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The effect of temperature on drop size of black liquor sprays Bennington, Chad Patrick Joseph 1983

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THE EFFECT OF TEMPERATURE ON DROP SIZE OF BLACK LIQUOR SPRATS by CHAD PATRICK JOSEPH BENNINGTON B.Sc, The University of British Columbia, 1979 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in THE FACULTY OF GRADUATE STUDIES Department Of Chemical Engineering We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA October 1983 Chad Patrick Joseph Bennington, 1983 I n p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f t h e r e q u i r e m e n t s f o r an advanced degree a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , I a g r e e t h a t t h e L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and s t u d y . I f u r t h e r agree t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y p u r p o s e s may be g r a n t e d by t h e head o f my department o r by h i s o r h e r r e p r e s e n t a t i v e s . I t i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l n o t be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . Department o f Chemical Engineering The U n i v e r s i t y o f B r i t i s h C o l u m b i a 2075 Wesbrook P l a c e V a n c ouver, Canada V6T 1W5 D a t e September 30, 1983 w.-f> ( 2 / 7 9 1 ABSTRACT The effect of temperature on drop size of black liquor sprays produced by small grooved-core nozzles at near boiling point conditions was investigated. It was found that increasing temperature through the boiling point decreased the Sauter mean diameter in a smooth manner, by a magnitide accounted for by the viscosity decrease. In contrast, water sprayed through the same nozzle under similar conditions showed a near step increase in mean drop size for the same temperature increase through its boiling point. The mass-weighted distributions of drop size for black liquor sprays were much broader than those of water, or glycerol/water solutions having the same viscosity as black liquor. Increasing the temperature through the boiling point of black liquor shifted its drop size distribution to smaller diameters. - i i i -TABLE OF CONTENTS Page ABSTRACT i i TABLE OF CONTENTS i i i LIST OF TABLES v i LIST OF FIGURES v i i 1. INTRODUCTION 1 2. LITERATURE REVIEW 4 2.1 Kraft Recovery Furnace Operation 4 2.2 Physical Properties of Black Liquor 8 2.3 Atomization 9 2.4 Liquid Flashing 12 3. EXPERIMENTAL WORK 14 3.1 Objectives 14 3.2 Apparatus 14 3.2.1 Spray Bomb 14 3.2.2 Sampling Cell 16 3.2.3 Sampler 18 3.2.4 Nozzles Used 18 3.3 Test Procedure 18 3.3.1 Sample Preparation and Liquid Spraying 22 3.3.2 Spray Sampling and Sampling Location 22 3.3.3 Measurement of Drop Size 23 3.4 Calculation of Spray Parameters 25 3.4.1 Mean Drop Size Diameter of Sprays 25 3.4.2 Velocity 27 3.4.3 Orifice Diameter 27 3.4.4 Liquid Physical Properties 27 3.5 Measurement of Black Liquor Viscosity 29 3.6 Experimental Spray Tests 29 4. RESULTS AND DISCUSSION 32 4.1 Black Liquor Viscosity....... 32 4.2 Spray Mass Distribution 35 4.3 Analysis of Spray Drop Diameter Measurements 37 - iv -Page 4.3.1 Mathematical Representation of Spray Drop Size Distribution 37 4.3.2 Determination of Parameters in Correlation Equations from Drop Size Measurements 40 4.3.3 Effect of Velocity on Mean Drop Size 45 4.3.4 Effect of Viscosity on Mean Drop Size 47 4.4 Results of Spraying Superheated Water 49 4.5 Atomization of Black Liquor Above and Below it s Boiling Point 55 5. SUMMARY AND CONCLUSIONS 68 6 . RECOMMENDATIONS FOR FURTHER WORK 70 NOMENCLATURE 71 REFERENCES 73 APPENDIX I: Kraft Process and Recovery Furnace Overview.. 78 1. The Kraft Process 78 2. The Recovery Furnace 81 2.1 Introduction 81 2.2 Recovery Furnace Operation 83 2.2.1 Combustion Engineering (CE.) furnaces 83 2.2.2 Babcock and Wilcox (B & W) Furnaces 84 2.2.3 Black Liquor Firing 87 APPENDIX II: Literature Review of Atomization in Grooved-Core Nozzles 90 1. Introduction 90 2. Mechanism of Jet Breakup 91 3. Dimensional Analysis of Atomization Phenomenon.. 92 4. Drop Size Distributions in Sprays 94 4.1 Characterization of Sprays 94 4.2 Measurement of Spray Drop Size 98 4.3 Problems Involved With Accurate Determination of Spray Size 99 - v -Page 5. Studies of Grooved-Core Nozzles 100 5.1 Turner and Moulton 100 5.2 Tate and Marshall 103 5.3 Mugele 104 5.4 Nelson and Stevens 104 5.5 Lapple, Henry and Blake 106 5.6 Kim and Saunders 106 5.7 Dombrowski and Wolfshon 107 5.8 Wang and Tien 109 6. Comparison of Grooved-Core Nozzle Studies 110 7. Atomization by Liquid Flashing 114 8. Summary and Conclusions 116 APPENDIX III: Review of the Physical Properties of Black Liquor 119 1. Introduction 119 2. Chemical Composition 119 3. Liquor Solids Content 120 4. Boiling Point Rise 122 5. Liquor Density 122 6. Surface Tension 122 7. Viscosity 126 8. Characterization of Liquor used in Study 127 APPENDIX IV: Computer Program for Spray Drop Size Distribution Analysis 135 APPENDIX V: Data 141 1. Nozzle Flow Rate Data 141 2. Black Liquor Viscosity Measurements 142 3. Glycerol/Water Solution Properties 143 4. Introduction to Spray Analysis Data Tables 144 5. Part I - Atomization of Water and Glycerol/Water Mixtures 145 6. Part II - Atomization of Water and Superheated Water 149 7. Part III - Atomization of Concentrated Black Liquor in Spraying Systems 1/4LNN2 Grooved-Core Nozzles. 151 8. Part IV - Mean Diameters Determined from Experimental Data 152 9. Part V - Mean Diameters of Averaged Black Liquor Tests 158 - v i -LIST OF TABLES Page 1. Summary of Grooved-Core Nozzle Dimensions 21 2. Data for the Measuring Systems Used in Black Liquor Viscosity Work 30 3. Power Dependence Found for Fundamental Spray Variables 42 II - l Mean Diameters Used to Describe Sprays 96 II-2 Summary of Dependence of Variables on the Mean Drop Size Produced by Swirl Jet Nozzles 112 II I - l Summary of Literature Work on Black Liquor Surface Tension 125 III-2 Summary of Literature Work on Black Liquor Viscosity 128 III-3 Chemical Analysis of West Coast Black Liquor Tested 131 V-l Tabulation of Experimental Measurements of West Coast Black Liquor Viscosity 142 V-2 Tabulation of Glycerol/Water Solution Physical Properties 143 V-3 Atomization of Water and Glycerol/Water Mixtures 145 V-4 Atomization of Water and Superheated Water 149 V-5 Atomization of Concentrated Black Liquor in Spraying Systems 1/4LNN2 Grooved-Core Nozzle 151 V-6 Mean Diameters Determined from Experimental Data 152 V-7 Mean Diameters of Averaged Liquor Tests 158 - v i i -LIST OF FIGURES Page 1. Schematic of Spray Bomb Apparatus 15 2. Layout of Spray Apparatus 17 3. Spray Curtain and Sampler Details 19 4. 1/4LNN Series Atomizing Nozzles Component Sketch 20 5. Drop Size Photographs of Representative Water Sprays.. 24 6. Schematic Diagram of Videoplan Components 26 7 . Plots of Shear Stress Versus Shear Rate for Representative Black Liquor Tests 33 8. Experimentally Determined Viscosities 34 9. Spray Mass Flow Distribution 36 10. Square-Root Normal Representation of Drop Size Distributions 38 11. Log Normal Representation of Drop Size Distributions 39 12. Comparison of Predicted and Measured Spray Drop Sizes 44 13. Effect of Velocity on Mean Spray Drop Size 46 14. Effect of Viscosity on Mean Spray Drop Size 48 15. Effect of Liquid Superheat on a Simple Water Jet 50 16. Effect of Liquid Superheat on Water Sprays Produced from Grooved-Core Nozzles 51 17. Effect of Liquid Temperature on the Mean Drop Size of Sprays Produced by Grooved-Core Nozzles 53 18. Effect of Water Temperature on the Mass Distribution of Sprays Produced by Grooved-Core Nozzles 54 - v i i i -Page 19. Number Distribution Sampled from the Cone of a Superheated Water Spray 56 20. Drop Size Photgraphs from Sprays of Water, Glycerol/Water and Black Liquor 58 21. Effect of Viscosity on the Mean Drop Size of Black Liquor Sprays 59 22. Example of 'Poor Atomization' Found for Some Black Liquor Sprays 61 23. Temperature Dependence of Black Liquor Sprays 63 24. Mass Distribution of Black Liquor Sprays 65 25. Mass Distribution of Selected Water, Glycerol/Water and Black Liquor Sprays 67 1-1 Diagram of the Kraft Process 79 1-2 Nozzles Used for Black Liquor Firing in North American Recovery Furnaces 85 1-3 Schematic of a Combustion Engineering Recovery Furnace 86 I I - l Comparison of the Number Distribution and Mean Diameters of a Typical Spray 97 II-2 Estimated Error of Sauter Mean Diameter Based on Sample Size 101 II-3 Comparison of Drop Size Correlations 113 I I I - l Kraft Liquor Boiling Point Rise Data From Several Sources 123 III-2 Temperature Dependence of 65% Solids Content Black Liquors 129 III-3 West Coast Black Liquor Density (90°C) 132 III-4 West Coast Black Liquor Viscosity 134 V-l Flow Rate Data for 1/4LNN Series Nozzles 141 - ix -ACKNOWLEDGEMENTS I sincerely thank the following individuals for their help throughout the course of this project: My supervisor, Dr. R.J. Kerekes for his suggestions and guidance. The members of my advisory committee Dr. J.R. Grace, Dr. K.L. Pinder and Dr. I.S.D. Shaw for their helpful advice. Mr. S.K. Shroderus, Mr. A.R. Smith and Mr. F. Willamson of MacMillan Bloedel Limited for their help and suggestions. The members of the PAPRICAN group at UBC, in particular Georgina White for her help. The members of the chemical engineering department office, shops and stores for their assistance. Meriza Bennington, Elizabeth Grace and Sonya Ocampo-Gooding for their patient image analysis of the droplet photographs. Ron, Linda, Mike and Dwight for the distractions of diving, camping and skiing. The financial support of the Natural Sciences and Engineering Research Council of Canada is recognized and greatly appreciated. INTRODUCTION The size of drops in a black liquor spray is an important parameter in the operation of a kraft recovery furnace. Though every spray contains a range of drop sizes, the upper and lower bounds of this range define limits within which furnace operation must be stable and controllable. When the drop size is too large, the liquor droplets do not dry sufficiently before they reach the char bed. This lowers the temperature in the char bed resulting in a poorer reduction efficiency, higher emission of H2S, and could lead to a significant lowering of furnace temperature (a "brown out"). When the drop size is too small, droplets are entrained by the combustion gases and carried upwards in the furnace (carryover). In this case, smelt production decreases because insufficient liquor reaches the char bed, the upper furnace temperature increases, and the deposition of particulate matter on the boiler tubes causes heat transfer fouling. While increased fouling necessitates more frequent soot blowing, conditions could arise where soot blower resistant deposits form resulting in boiler passage plugging [ 1 ] . Increased carry over also increases the recycle of deadload chemicals through the recovery cycle (ash particles captured in the boiler and recycled with the incoming black liquor) and the emission of particulate matter from the boiler. To avoid the foregoing problems, recovery boilers are operated with a "coarse" spray, that i s , a spray which has a drop size distribution that maintains char bed temperature but minimizes - 2 -particulate carryover. Many variables affect this desired drop size distribution, for example: furnace operation, nozzle geometry, and black liquor properties. However, few of these variables can be changed during on-line operation. Furnace operation, for example, is largely determined by the installation. Nozzle geometry is usually fixed; liquor flow rate and solids content are determined by production rate. However, there is one easily-changed operational variable: the liquor temperature. This is commonly used to achieve on-line control of spray drop size. It is well known from operational experience that black liquor temperature has a significant effect on furnace operation [2,3,4]. In practice the liquor f i r i n g temperature is carefully controlled by steam injection upstream of the boiler nozzles. Here slight temperature changes are used to control the quantity of material (inventory) in the furnace char bed. On occasion, very significant changes in recovery furnace operation can be made with relatively small changes ln liquor temperature. For example, i t has sometimes been observed in practical experience that a furnace brown out can be overcome by changing the liquor temperature only a few degrees. While much is known from practical experience about the effect of liquor temperature on recovery boiler operation, very l i t t l e specific detailed technical information on this subject has been published in the literature. There i s , however, considerable published information on atomization theory, and a lesser but significant amount on black liquor properties to permit some prediction of the effect of temperature. - 3 -Fir s t , the drop size of any spray is known to be dependent on the viscosity of the liquid. Black liquor viscosity is known to be very temperature dependent. Second, flashing in or just after a nozzle can significantly affect spray characteristics. Black liquor is commonly sprayed at or near its boiling point. Thus, two factors, viscosity and flashing may individually or in combination significantly affect the sprayability of black liquor when temperature changes take place. The objective of this thesis is to determine the effect of temperature on the drop size of black liquor sprays at near boiling point conditions. The specific aim is to determine whether small temperature changes can cause significant changes in drop size - changes large enoughs to be considered an instability. The Investigation begins with a detailed search of the literature in the fields of recovery furnace operation, atomization theory, and black liquor properties. - 4 -2. LITERATURE REVIEW 2.1 Kraft Recovery Furnace Operation There are two types of recovery furnaces common in North American kraft pulp mills: the Combustion Engineering (CE) furnace and the Babcock and Wilcox (B & W) furnace. While both perform the same recovery function, there are some key differences in operating strategy between them. One of these is the method used to fi r e black liquor in the furnace. CE furnaces practice suspension firing in which the black liquor, atomized in grooved-core nozzles, evaporates and burns as i t fa l l s as droplets onto the char bed. The drop size distribution of the spray determines the degree of bed cooling and particulate carryover. Accordingly, CE furnace operation requires control on both the upper and lower limits of drop size. In contrast, B & W furnaces spray the liquor on the opposite furnace wall and rely upon wall drying for liquor evaporation. The B & W method of liquor f i r i n g is less sensitive to spray drop size since control is only required on the lower limit to ensure that the drops do not become too small. This thesis w i l l concentrate on atomization in grooved-core nozzles characteristic of CE furnace f i r i n g because this method of furnace operation is likely to be more sensitive than the B & W furnace to changes in spray drop size. The scientific literature pertaining to black liquor f i r i n g and recovery furnace operation recognizes the importance of black liquor - 5 -atomization on the control and efficiency of recovery furnaces [2,3,4]. However, despite this, there is l i t t l e detailed information available on black liquor atomization. In fact, the only work involving actual in situ measurement of black liquor drop size has been done by Sandquist [5]. In this work, motion pictures were taken of black liquor sprays through an observation port at the firing gun level in the recovery furnace. Black liquor droplets recorded on the film were then measured. A typical black liquor spray produced by an impingement nozzle for suspension f i r i n g (Scandanavian practice) gave an average drop size of 2.1 mm for typical operating conditions.* Other investigators have attempted to describe or estimate the optimum size of a black liquor droplet required for efficient recovery furnacy operation. The common reference to a "coarse" drop size is an indication that fine spray formation and the problems associated with particulate carryover are undesirable. Nelson [6] stated that the flash dried liquor drop should be spherical and about 1/2 inch in diameter. He used the "popped popcorn" analogy to describe the appearance of the dried droplets upon reaching the char bed. V'yukov [7] stated that the liquor droplet size must be such that droplets reaching the hearth contain 8-10% moisture for optimum reduction efficiency. He presented a system of equations to solve for this optimum size. *The test conditions were as follows: nozzle orifice diameter =• 34 mm, nozzle operating pressure = 18.9 psig, nozzle flow rate = 10.6 1/s, black liquor solids content = 63%, black liquor f i r i n g temperature = 98°C, black liquor viscosity = 115 cp. - 6 -Modelling has also been attempted as a means of describing recovery furnace operation [3, 8, 9]. The most recent one, by Merrian [10], is a steady-state model of the entire kraft recovery furnace. It predicts that a drop size diameter close to 1.5 mm is required for stable f i r i n g in the CE furnace. However, the notion of a single optimum drop size can be misleading because, in actual fact, a distribution of drop sizes is produced by any spray nozzle. The sensitivity of the black liquor spray to temperature is well known. Galtung and Williams [3] stated that "the drop size distribution is extremely sensitive to the liquor temperature as a few degrees w i l l change a coarse spray into a fine mist." Jutila et a l . [4] studied the actual effect of changes in firing variables on the temperature profile in a recovery furnace. They found that changing the liquor temperature by as l i t t l e as 2°C introduced a noticable difference in the boiler temperature profile. They stated that liquor temperature control could be used to control the location of combustion and heat release in the furnace. They gave a narrow temperature range of 117 to 119°C for optimum liquor f i r i n g . The mechanism by which temperature effects drop size is a question of contention. Viscosity is believed to be important by some investigators. For example, Kennedy [11] specified that black liquor should be sprayed at 125 cp, but did not give any indication of what would happen to the liquor drop size i f the viscosity changed. Computer models, like Merriam's [10], used atomization models that allowed drop size to vary as a power of the viscosity. The other effect of - 7 -temperature - liquor flashing - is believed to be important by several investigators. Hochmuth [12] described the firing of black liquor as one of partial flashing of the liquor's water content. The liquor, heated above its atmospheric boiling point to 112 to 115°C is sprayed into the furnace. Upon leaving the nozzle, the liquor partially flashes, causing each droplet formed to expand to many times i t s original size, thereby increasing the available surface area for moisture removal. He suggested that changes in liquor temperature can be used to control the black liquor drop size. Reiche [13] also discussed flashing in the black liquor sprays in recovery furnaces. He cited two possibilities: droplets could either burst into smaller particles, or expand to larger ones due to the formation of a tough skin around their surface that traps the vaporizing moisture. There is a third atomization phenomenon sometimes found In recovery furnaces - liquor roping [3]. This occurs when the liquor temperature Is too low for spray formation. The resulting liquor flow can quickly quench the char bed and cause a black out. It is reportedly caused by high liquor viscosity. It is apparent upon reviewing the literature that atomization of black liquor is a complex problem about which l i t t l e is known. Temperature is known to be important in establishing the drop size of the liquor spray, but the independent effects of viscosity and liquid flashing, both of which are affected by liquor temperature, is not clear. - 8 -2.2 Physical Properties of Black Liquor Black liquor is an aqueous mixture of dissolved lignin, heraicelluloses, and extractives from the pulped wood, and inorganic compounds formed from the cooking liquor of sodium hydroxide and sodium sulfide. The exact composition and physical properties of any given black liquor is determined by the particular wood species and the pulping conditions. Because black liquor properties change dramatically with liquor solids content (the gravimetrially determined solid material remaining after the liquor is dried under a fixed set of conditions, usually expressed as a percent (see appendix II)) and temperature, i t is common to characterize a liquor by these variables. For safe f i r i n g in the recovery furnace liquor, solids content must be kept above 58% [14]. The usual practice is to f i r e the liquor at higher solids content, typically 62-68%. The physical properties of interest in liquor f i r i n g are: boiling point rise, density, viscosity, and surface tension. The measurement of these properties at solids contents greater than 55% is d i f f i c u l t . Even the measurement of black liquor solids content can vary by as much as five percent, depending on the test procedure used. Nevertheless, values for these properties have been measured and reported in the literature. A detailed literature review of these properties is reported in appendix III. The findings are summarized below. Boiling point r i s e : The boiling point rise of black liquor has been investigated by a number of researchers. A good summary is given by Clay and Grace [15]. Figure III-l shows the boiling point rise as a - 9 -function of liquor solids content. At a typical f i r i n g solids content of 65%, most investigators report the boiling point rise to be 12 to 15°C above the water boiling point. Density: The measurement of liquor density is straightforward. A number of correlations of density versus solids content are given in the literature (see appendix III-4). Surface tension: Although attempts have been made to measure the surface tension of black liquor at typical solids contents used in f i r i n g (60-70%), most published data are for 50% solids content and lower. However, Soderjelm and Koivuniem [16] did report a value for black liquor at 61% solids, but suspected i t s accuracy because of experimental d i f f i c u l t i e s . The extrapolation of published data to liquor solids contents in the f i r i n g range suggest that surface tension Is likely to be between 30 and 40 dynes/cm. Viscosity: Black liquor viscosity is a strong function of solids content and temperature. The published data for viscosity at a typical solids content used in liquor f i r i n g (65%) are compared in figure III-2. The values In this figure vary widely, but appear to cluster about two levels which differ by a factor of more than ten. No indication of which level is appropriate for any given liquor is given in the literature. Thus the viscosity of an unfamiliar liquor must be measured. 2.3 Atomization A vast body of literature exists on theoretical and experimental studies of atomization. Of this, only a small portion is directly - i n -applicable to this study. A search of the appropriate literature was made and is described f u l l y in appendix II. What follows is a summary of the pertinent parts of this search. The f i r s t requirement of any atomization study is to choose a suitable method of characterizing the drop size in the spray. A l l sprays contain a distribution of drop sizes; thus, a s t a t i s t i c of the distribution i s necessary to represent the spray. The selection of the s t a t i s t i c is dictated by the objective of the study. Black liquor is atomized for evaporation and combustion; accordingly, a mean diameter appropriate to these processes - the Sauter mean diameter - was chosen. The Sauter mean diameter, d$2> is the diameter of the droplet having the same ratio of volume to surface area as the entire spray. This diameter is commonly used in atomization studies, and therefore readily permits comparison with other investigations in the f i e l d . Although some theoretical analyses have been made to predict the characteristics of sprays from hydrodynamic f i r s t principles [17], in practice the prediction of spray drop size is made from correlations. These are based on experimental data and the known dimensionless parameters that govern atomization. This holds true for the grooved-core nozzle of interest in this study. Although spray correlations can take many forms, most can be rewritten in the following non-dimensional and dimensional forms. X X _ V D a T 7 6 — = K Re We - 11 -, _ v _a TTb c d e d = K D U p u c T XX (2) For hydraulic swirl nozzles, of which the grooved-core nozzle is one type, the correlation given by Lappel, Henry and Blake [18] is the most general, encompassing the data published in the literature prior to 1967. This correlation i s : As with most spray correlations published in the literature, limitations on the applicability of this equation are not readily apparent or clearly stated. Nevertheless, they exist and may be important, as shown below. First, the above correlation was developed for a generic nozzle type - the hydraulic swirl nozzle. This generic category encompasses many specific types and geometries of nozzles. This wide application introduces an error, and may well account for some of the 50% error found in the use of equation (3). Second, limits on the range of values of the variables for which a correlation is applicable are usually not given, although i t is well known in practice that practical operating limits exist. For any given nozzle and liquid there is a minimum operating pressure required to atomize the liquid. Just above this lower limit is an operating range over which only partial or incomplete atomization occurs. Eventually, an operating range is reached where the spray becomes fully developed [19]. The correlations usually apply to - 5.5 Re -0.20 We -0.25 (3) - 12 -this latter range. An upper limit is reached when further increases in atomizer pressure do not further decrease the spray drop size. This upper limit is evident in graphs supplied by makers of commercial nozzles, e.g. [20]. Despite the foregoing shortcomings, correlations provide the only quantitative method for predicting the drop size of sprays and the dependence of drop size on specific variables. 2.4 Liquid Flashing As stated earlier, black liquor f i r i n g in recovery furnaces takes place at temperatures near the liquor boiling point. When heated liquids under pressure flow into a region of lower pressure in which the liquid is superheated, the liquid must partially vaporize (flash) to attain equilibrium with its surroundings. This sudden flashing may affect spray formation. Past studies have shown that a superheated water jet emerging from a plain circular orifice can be shattered to a sufficient extent to form a spray comparable to that created by other atomizing devices [21]. In other words, flashing alone can produce a spray. When a grooved-core nozzle is used in place of a circular o r i f i c e , a spray is formed without superheat. The effect of liquid superheat in this case is unknown. No information could be found on this subject in the literature, nor is the effect obvious. On one hand, flashing could diminish the spray drop size by superimposing a spray - 13 -forming mechanism on the one already there. On the other hand, i t could lead to two phase flow within the nozzle and disrupt the e x i s t i n g spray forming mechanism. As i s evident from the discussion thus f a r , temperature i s known to e f f e c t spray drop s i z e , but the mechanism by which i t does so and the magnitude of the changes i t introduces are not known. An experimental program to measure the e f f e c t of liquor temperature on spray formation i s described i n the following section. A major objective i s to determine the r e l a t i v e importance of liquor v i s c o s i t y and liquor superheat ( f l a s h i n g ) . - 14 -3. EXPERIMENTAL WORK 3.1 Objectives The objective of this thesis was to determine the effect of temperature on the drop size of black liquor sprays in grooved-core nozzles near boiling point conditions. This f i r s t required establishing the independent effect of viscosity and liquid temperature on drop size. The strong interdependence between temperature and viscosity i n black liquor did not permit this, so glycerol/water solutions were used to measure the effect of viscosity change without temperature change. Heated water was used to study liquid superheat. The experimental apparatus and program are discussed below. 3.2 Apparatus 3.2.1 Spray Bomb Sprays were produced in a desk top apparatus from which liquids could be atomized through various nozzles at pressures up to 600 psig. This 'spray bomb' is shown in Figure 1. It consists of a 1.6 1 stainless steel insulated cylinder to hold the liquid at elevated temperature and pressure. The latter was controlled by an air or nitrogen gas pad over the liquid regulated by a valve from a gas cylinder. The liquid temperature was varied by adjusting the voltage supplied to an internal 600 watt heater, with uniformity maintained by an internal s t i r r e r magnetically coupled to a variable speed drive. Figure 1 Schematic of Spray Bomb Apparatus. 1 K D 1 N i t r o g e n o r a i r c y l i n d e r 2 " S p r a y Bomb" 3 H i g h p r e s s u r e r e d u c t i o n v a l v e i] B l e e d v a l v e 5 V a r i a b l e s p e e d s t i r r e r 6 I n t e r n a l h e a t e r 7 I n s u l a t e d & h e a t e d t u b e 8 N o z z l e 9 M a i n Flow V a l v e (p) P r e s s u r e Gauge (J) T h e r m o c o u p l e - 16 -During spraying, the liquid was discharged through an insulated, heated tube to which various nozzles could be coupled. Temperatures and pressure were monitored inside the spray bomb and just upstream of the nozzle as shown in figure 1. To contain the spray downstream of the nozzle, a spray curtain (76 cm x 46 cm 0) of a 1/16" polycarbonate sheet was placed below the nozzle. A large plastic bag was fi t t e d over the base of the spray curtain to collect the liquid for reuse. A blower was also f i t t e d to the base to remove air entrained by the spray, thus preventing air currents from forming inside the curtain and carrying droplets back to the sample point. Two ports were cut into the spray curtain to hold and position the spray sampler. Photographs of the spray apparatus are given in figure 2. 3.2.2 Sampling c e l l The mean drop size of each spray was measured by capturing samples of the spray in a sample c e l l containing varsol. This capture technique, described by Rupe [22], permits the impinging droplets to retain their spherical shape by supporting them in an immisible f l u i d having a slightly lower specific gravity (varsol). The sample c e l l consisted of a 9.6 mm diameter, 7 mm deep cylinder secured to a microscope slide. The slide surface, forming the bottom of the sample c e l l , had been previously coated with a silicone based surfactant to prevent the captured drops from wetting the glass surface. Figure 2: Layout of Spray Apparatus. - 18 -3.2.3 Sampler The sampler consisted of a stationary plexiglass rod with a slot cut into its surface to hold the sample c e l l . A rotatable plexiglass tube having a "window" in line with the sample c e l l was fit t e d over the stationary rod. With the window closed, the sampler was positioned in the spray at the desired location. It was secured there by rings fitted to the outside of the spray curtain as shown in figure 3. 3.2.4 Nozzles Used Commercial gooved-core nozzles manufactured by the Spraying Systems Company were chosen for this study. Five nozzles of the 1/4LNN series with orifice diameters of 0.0406 cm to 0.2184 cm were used [23]. Of available commercial small-scale nozzles these were the closest that could be found to the geometry of grooved-core nozzles used in recovery furnaces. Figure 4 shows a sketch of nozzle components and table 1 gives a l i s t of important nozzle geometric parameters. While a l l the nozzles are grooved-core nozzles, they were not geometrically similar (having two, four, or six grooves, etc.). Nozzle parameter A, the ratio of the orifice area to the groove area, describes this difference to some extent. 3.3 Test Procedure Each test run consisted of the following steps: sample preparation, liquid spraying, sampling, sample photography, and drop - 19 -Figure 3: Spray Curtain and Sampler D e t a i l s . - 20 -Figure 4: 1/4LNN Series Atomizing Nozzles Component Sketch. ZTZM PART NO. DESCRIPTION BRASS STAINLZS5 STSSX. i 1206 1206-SS Cap, Brass o r S t a i n l e s s S t e e l 2 1207---SS 1207-«-SS O r i f i c e I n s e r t , S t a i n l e s s S t e e l 3 1195—-SS 1195-—SS Cora T i p , S t a i n l e s s S t e e l 4 2930-*-5S 2930-»-SS Screen, S t a i n l e s s S t e e l s 1194-* U94-*-SS Core T i p Holder & S t r a i n e r 3ody Sub-Assembly, Brass o r S t a i n l e s s S t e e l o 1210 1210-35. Body, Brass o r S t a i n l e s s S t e e l . 1/4" NPT(M) 1/4LSW— Atomizing Nozzle, Brass 1/4LUN-SS-— Atomizing Nozzle. S t a i n l e s s S t e e l •Specxsy Screen Mesh S i z e , Cora S i z a o r I n s e r t Sizes i / 4 L i r j — Aim 1/4LMN-SS-A T O M I Z I H G H O Z Z L Z S s PMYING SYSTEMS CD. NORTH AVENUE AT 3CHMALZ BOAO WHKATON. I L L . DATS : . ' U / 3 i NO. ?L i. 4L:IM-Table 1: Summary of Grooved-Core Nozzle Dimensions Core Nozzle Orifice Core No. Width Height Designation Diameter Insert Grooves cm cm A cm No. 1/4LNN.6 .0406 206 2 .0152 .0254 1.6767 1/4LNN2 .0711 216 2 .0406 .0610 0.8016 1/4LNN8 .1524 225 2 .0635 .0940 1.5281 1/4LNN14 .1930 421 4 .0508 .1016 1.4170 1/4LNN26 .2184 625 6 .0635 .1219 0.8066 Area of nozzle or i f i c e  Cross-sectional area of grooves upstream of nozzle orifice - 22 -size measurement. Each of these steps i s described in detail in the following sections. 3.3.1 Sample Preparat ion and L i q u i d Spraying Where necessary, liquids for spraying were prepared in advance. In the case of glycerol/water solutions, the correct proportions were mixed for the desired liquid viscosity. For black liquor, dilute black liquor from the m i l l had to be concentrated to the desired solids content. This was achieved by heating well-stirred weak black liquor ( = 36% solids) on a hot plate while maintaining a nitrogen pad over the evaporating liquid. The prepared liquids were then charged into the bomb. Where necessary, heating and s t i r r i n g were used to maintain the desired test conditions. The liquid was then sprayed. 3.3.2 Spray Sampling and Sampling Loca t ion A l l spray sampling was made at a fixed location. The vertical position was in a plane 14 cm below the nozzle, a distance at which a l l sprays were f u l l y developed and the spray density was low enough for easy sampling. The horizontal position (measured from the nozzle centerline) was separately chosen for each test to be the location of greatest mass flow in the spray. This varied with the nozzle, liquid, and operating conditions. The means for determining this location i s described in section 4.2. Before sampling, the sample c e l l was prepared by half f i l l i n g with varosol. It was then placed in the sampler. With the sampler - 23 -correctly positioned in the spray, droplets were captured by rotating the outer cylinder of the sampler to permit spray droplets to impinge on the c e l l . The exposure time of the c e l l was varied to obtain samples having an approximately equal droplet density. 3.3.3 Measurement of Drop Size After sampling, the sample c e l l was completely f i l l e d with varosol and a standard microscope cover slip was placed over the c e l l to eliminate the miniscus. The c e l l was then photographed using a 35mm camera through a Wilde M20 microscope having an effective magnification of 13.6 times. The effective magnification of the microscope was determined by photographing a specially-constructed calibration c e l l containing a stage micrometer. This was photographed under identical conditions to those used for the test runs. The precise magnification factor determined from the image of the stage micrometer was recorded on the film. This permitted accurate measurement of droplet sizes. To photograph the captured spray from a typical test run, the sample c e l l was divided into six to nine segments of equal area. Each segment was photographed onto one frame of a film. An identity number was assigned to each photograph, and a record was kept of each test condition (the liquid atomized, nozzle used, atomizer pressure and liquid temperature). A number of photographs of tests made with water are shown in figure 5. These tests were made with the same nozzle but varying atomizer pressure. - 24 -Figure 5: Drop Size Photographs of Representative Water Sprays. A l l tests made with the 1/4LNN2 grooved-core nozzle using water at 18°C sprayed into air. Samples taken from cone of spray. Magnification factor = 34.4X. Operating pressure: (A) 50 psig (B) 150 psig (C) 200 psig - 25 -After use, the sample c e l l was flushed with water and dried with a gas stream (canned photographic propellant was used). Oven drying was used i n i t i a l l y . However, the c e l l detached from the microscope slide after four or five cycles. The diameters of the drops in the photographs were measured using a Zeiss MOP/40 Videoplan semi-automatic image analyser with video overlay. Constant magnification was used throughout these tests, permitting the measurements to be converted to their actual sizes by a single scale factor. The drop diameter measurements were stored on floppy disks in the Videoplan for later analysis. A schematic diagram of the image analyser components is given in figure 6. This semi-automatic method of measurement proved to be very tedious: each of the 156 tests made required approximately two hours to complete. However, the procedure gave reliable measurements, even for the case of very dense sprays in which many droplets were touching. 3.4 Calculation of Spray Parameters 3.4.1 Mean Drop Size Diameter of Spray As described earlier, the Sauter mean diameter, d^2» w a s used to characterize the sprays. This drop size was calculated from measured drop sizes by f i r s t transferring the data from the Videoplan's floppy disk f i l e s to the UBC central computer. Here, the program given in appendix IV was used to compute a number of st a t i s t i c a l parameters, including the Sauter mean diameter, for each test. - 26 -Figure 6: Schematic Diagram of Videoplan Components. 1. Videoplan: Main computer 2. Television Monitor 3. Computer Keyboard 4. Printer 5. Digitizer tablet 6. Microscope 7. High resolution television camera - 27 -3.4.2 Velocity The velocity used throughout these tests was the superficial velocity at the nozzle or i f i c e . This was calculated by dividing the known volumetric flow rate from the nozzle by the cross sectional area of the ori f i c e . The volumetric flow rate was measured as a function of atomizer pressure for each of the liquids in the grooved-core nozzles studied, and is given in figure V - l . Although the velocity determined by this method is not the velocity in the orifice (due to the presence of an air core and a tangential velocity component), i t is the velocity commonly used by investigators in this f i e l d . 3.4.3 Orifice Diameter The orifice diameter was obtained from the manufacturer's specifications for each nozzle [23]. These were listed previously in table 1. 3.4.4 Liquid Physical Properties The physical properties of the liquids used in this study were obtained from standard reference tables or measured by standard procedures. Water: The density, viscosity and surface tension of water were determined from tables published in the CRC handbook [24]. The viscosities of superheated water were estimated using a nomograph in Perry's handbook [25]. - 28 -Glycerol/Water Solutions; Glycerol and water solutions were prepared to give the desired viscosity levels. The refractive index of samples taken from each test solution were made at 20°C using an Atago refractometer. This permitted a good estimate of the weight fraction of the solutions using tables in the CRC handbook [24]. The density was estimated using these same tables, while estimates of the surface tension were made using the International C r i t i c a l Tables [26] . The viscosity of each solution was experimentally determined using a Haake RV 12 Rotovisco viscometer and the NV sensor system. A summary of the properties for each glycerol/water solution i s given in table V-2. Black Liquor; One black liquor from a typical coastal kraft m i l l in British Columbia pulping a hemlock/balsam mixture was used in these tests. The liquor sample was obtained from the oxidized strong black liquor storage tank. It was diluted at the mill site from 50.5% to 35.6% solids content to maintain liquor homogeneity during transport and storage. The physical properties of the liquor were estimated on the basis of liquor solids content. Density was determined using a correlation for the mill liquor tested. Surface tension was estimated to the best degree possible from findings reported in the literature (see appendix III). The viscosity of black liquor was measured as a function of liquor solids content and temperature, as described in the following section. Other properties of the liquor, including Its chemical analysis, were also determined and are presented in appendix III. - 29 -3.5 Measurement of Black Liquor Viscosity Black liquor viscosity was measured as a function of liquor solids content over the range of 38.2 to 68.8% solids and temperature over the range 26 to 127°C using a rotational viscometer (Haake RV12 Rotovisco). The sensor systems chosen for this analysis were the MV-400-I and the SV-400-II, details of which are given in table 2. The viscosity measurements were made using the manufacturer's recommended procedures [27]. A nitrogen purge was maintained over the liquor sample to minimize oxidation. Viscosity was measured over the range of shear rates obtainable with the bob and cup used while maintaining test temperature to within ± 0.5°C. 3 .6 Experimental Spray Tests In total, 156 spray tests to determine spray drop sizes for various liquids under various conditions were carried out. The f i r s t series consisted of 88 tests, using water and three glycerol/water solutions having viscosities of 14.7, 64.8 and 205 cp. These were atomized in the five 1/4LNN nozzles. The operating range for pressure was from 50 to 600 psig. In the second test series, 42 tests were carried out using heated and superheated water. A l l five 1/4LNN series nozzles were used, and discharge velocity was maintained at 851 ± 43 cm/sec. The final test series consisted of 26 tests using concentrated Table 2: Data for the Measuring Systems Used in Black Liquor Viscosity Work. Temperature Shear Rate Sample Radius of Radius of Sensor Range Ranj>e Volume Measuring Bob Measuring Cup System °C S~ cm mm mm MV-400-I -60 to 300 2.34 to 1198 50 20.04 21 SV-400-II -60 to 300 0.89 to 456 6 10.1 11.55 - 31 -black liquor in one nozzle and at one fixed operating pressure. The operating temperature was varied to pass through the estimated boiling point of the liquor. The conditions and results for a l l tests are given in Appendix V. - 32 -4. RESULTS AND DISCUSSION 4.1 Black Liquor Viscosity The measured values for black liquor viscosity are presented in table V - l . Although the liquor did exhibit shear thinning during some tests as reported in the literature [28, 29], this effect was not observed for a l l tests. The reported viscosities were determined by plotting the shear stress against the shear rate and f i t t i n g a line by linear regression through the data points as shown in figure 7. The viscosity values* were correlated with solids content and temperature using an equation similar to that suggested by Jagannath [30]. Agreement between this equation, u(cp) = 0.0459 exp{l.22 x 10~2 (% solids) + 4.20 x 10~3 (% s o l i d s ) 2 + 8.04 x 10~2 (T°C) +3.15 x 10~4 (T°C) 2 - 3.25 x 10"3 (% solids) (T°C)| (4) and the experimental data i s shown in figure 8. This equation was used to extrapolate the measured data to determine the viscosity dependence of a 65% solids liquor as a function of temperature for comparison with the findings of other investigators. Agreement was good as shown in *Viscosity values of black liquor are "apparent viscosities" that do not take into account possible non-Newtonian behaviour at high solids content and high shear rates in nozzles. - 33 -Figure 7: Plots of Shear Stress Versus Shear Rate for Representative Black Liquor Tests. - 34 -Figure 8: Experimentally Determined V i s c o s i t i e s . 10,000 , r 10 20 30 40 50 60 70 80 90 100 110 120 130 140 T E M P E R A T U R E (°C) - 35 -figure III-3. Thus, we may estimate the viscosity of the black liquor at the mill firing conditions (68% solids and 115°C) to be approximately 175 cp. 4.2 Spray Mass Distribution A grooved-core nozzle produces a hollow cone spray with air in i t s core and the major part of the liquid mass flow concentrated in a conical ring about the nozzle axis. As described earlier (section 3.3.2), our horizontal location of sampling was in this conical ring. To determine its location, the mass flow profile was measured in 1 cm increments in a plane 13 cm below the nozzle. The mass profile for a typical operating condition (water at 18°C atomized through a 1/4LNN2 nozzle at 190-200 psig) is shown in figure 9. This distribution clearly shows the major mass flow to be centered in a cone approximately 7 cm from the nozzle. This corresponded to the visually observed center of mass flow and was the sampling position chosen for this test condition. The sample window indicated on figure 9 shows the size of the sample c e l l relative to the mass distribution in the spray. Since a major objective of this thesis was to look for large changes in drop size caused by temperature change with other factors remaining constant, we only took samples from one position in the spray for each test. A l l sprays were sampled at a vertical location 14 cm below the nozzle and a radial distance corresponding to the major mass flow as determined by visual observation. Figure 9: Spray Mass Flow Distribution. " 1— T — I — I — r l 1 1 r i — i — r J— i—i i i i J 1 1 1 L J i i i i L 5 6 8 9 10 11 12 13 DISTANCE FROM NOZZLE CENTERLINE ( C M ) 1/4LNN2 Nozzle, 190-200 psig, water at 18°C, sampled 13 cm below nozzle. - 37 -4.3 Analysis of Spray Drop Diameter Measurements 4.3.1 Mathematical Representation of Spray Drop Size Distribution The drop size distribution of the test samples were found to be best described by the square-root normal distribution function given below: . , 1/2 - 1/2.2 f(x) » expj-i = s/2~it 2s The suitability of this equation is demonstrated by the goodness of a straight line f i t to the plotted values of the square-root of the droplet diameter against i t s cumulative number fraction on probability paper. Such a f i t for a number of tests is shown in figure 10. The appropriateness of the square-root normal distribution for characterizing spray drop size distributions is consistent with the findings of other investigators [31-34]. A commonly used alternative distribution, the log normal distribution [35], is plotted for the same tests in figure 11. It gives a poorer representation of the data, particularly at the ends of the distribution. The Sauter mean diameter was estimated directly from the spray drop size data by the following equation: Figure 11: Log Normal Representation of Drop Size D i s t r i b u t i o n s . % L E S S THAN - 40 -n 3 E 4, d i=l d32 = < 6 ) E • A i=l 1 1 This diameter is used to represent the mean drop size of the spray. 4.3.2 Determination of Parameters i n Correlation Equations  from Drop Size Measurements Earlier in section 2.3, we described the use of correlation equations as the common means of predicting drop size in sprays. The suitability of these equations for this purpose was evaluated by f i t t i n g the equations to our data. The mean diameters from tests conducted at room temperature (where l i t t l e evaporation takes place (Series I, table V-3)), were fitted to the following two equations: Y = K R e a WeP (1) K» Rea' WeP* A Y (7) Several mean diameters, d 1 Q , d 3 0 and d 3 2 were used as the basis of these correlations. The curve f i t t i n g was achieved by a multiple regression program (UBC TRP [36]) after the equations had been linearized by taking logarithms. Each data point was weighted based on - 41 -an estimate of i t s error. This error estimate was based on the number of droplets sampled in each test using a relationship developed by Bowen and Davies [37] (see Appendix II). Of these two equations, equation (1) proved to best represent the data. The addition of the nozzle geometric parameter, A, to the equation did not improve the f i t of the data enough to warrant i t s further use. The power dependence of each spray variable was determined from the f i t obtained for the non-dimensional equation (1). By rewriting this equation in i t s dimensional form (equation (2)), each exponent was determined from the known values of a and S. d _ = K D ( 1 + a + P ) U ( a + 2 P } o ( a + P ) a~ a a-"*5 xx u a ^ (8) Table 3 gives the values of the exponents so obtained. There is clearly good agreement between the average power dependence found here and those reported by Lappel et. a l . [18]. In fact the measured values a l l l i e within the range reported by previous investigators (see Table II-3). While the measured dependence of the powers of the various variables agrees well with those reported in the literature, the prediction of individual values of drop size is poor. For example, the correlation determined for the Sauter mean diameter: = 1.56 Re"* 1 8 We"*18 (9) Table 3: Power Dependence Found for Fundamental Spray Variables. Mean Drop Size Correlated Recommended by Variable dio d30 d32 Average s Lappel et a l . [18] D 0.47 0.56 0.64 0.56 0.09 0.55 U -0.86 -0.69 -0.53 -0.69 0.17 -0.70 P -0.53 -0.44 -0.36 -0.44 0.09 -0.45 H 0.19 0.19 0.18 0.19 0.01 0.20 a 0.33 0.25 0.18 0.25 0.08 0.25 - 43 -does not represent the data well, as is shown by the large scatter in figure 12. Thus, the precision for any individual point is low. The mean error for any single determination is approximately 50%. Such a large error may, however, be expected. When other investigators have specified confidence limits, they too report large errors of the order of 12% to 50% [18, 38]. There are a number of possible sources for the large error in equation (9). These are: 1. Nozzle geometry: Geometric dissimilarities between nozzles of one generic type (in this case the grooved-core nozzle) would change the atomization conditions (e.g., the axial and tangential velocity components) in ways that could not be accounted for by the simple equation forms. The geometric factor, A, did not account for these differences. 2. Sampling errors: The chosen sampling point, that is the cone of maximum liquid mass flow in the spray, may not be representative of the entire spray. Also, the sample may have been affected by the sampling technique. 3. Sample size: The number of droplets sampled in each test governs the accuracy with which the true population mean can be determined. For the majorty of tests the sample size was greater than 1000 drops, but in some cases sample sizes of less than 500 drops were obtained. For a test sample size of 500 drops, estimates by Bowen and Davies [37] place the error in estimating d 3 2 , due to sample size alone, at 17.5%. - 45 -4. Limits on range of variables: A l l data obtained in test series I were used in evaluating the correlation, even data for the case where sprays had reached a limiting condition, i.e. where further changes in the independent variable did not further change the mean drop size. This factor was described in section 2.3, and is discussed in more detail in the following sections. In summary, the correlation equation for Sauter mean diameter derived from these test data gives a power dependence of the spray variables in agreement with values published in the literature. However, the scatter of the data about the correlation equation is large. Therefore, there can be a large error when the equation is used to predict mean drop size for a given case. This error may be in part due to shortcomings in the measurements, but is also due in part to the inability of the correlation equation to adequately describe the atomization process. These factors limit the use of these equations for prediction of mean drop size. 4.3.3 Effect of Velocity on Mean Drop Size As shown in the findings of the literature search (Section 2.2 and Appendix II), the flow velocity and nozzle orifice diameter are the two major variables that effect mean drop size. The effect of velocity on spray drop size, dj2t when atomizing water in the five grooved-core nozzles of this study is shown in figure 13. As expected, there is considerable scatter in the data - a factor li k e l y due to the errors discussed in the previous section. There is - 46 -Figure 13: E f f e c t of V e l o c i t y on Mean Spray Drop Size. 2 5 0 2 0 0 o o ro T J LU N 00 Cu O or < LU 150 100 5 0 • i i — i — i — r 0 3 0 0 V4LNN26 1/4LNN14 A J 1/4LNN8 o 1/4LNN2 A 1/4LNN.6 • J 1 1 ' ' ' 5 0 0 7 0 0 1 0 0 0 1500 2 0 0 0 3 0 0 0 F L O W V E L O C I T Y (cm/sec) - 47 -also an unexpected decrease in mean drop size produced when the nozzle o r i f i c e diameter is increased from 0.0406 cm to 0.0711 cm. This finding cannot be explained, even by geometric differences between the two nozzles. The general finding of the data presented in figure 13 is that, for a given nozzle, the mean spray drop size decreases as velocity increases. This is consistent with the prediction of the correlation equations discussed ea r l i e r . In the case of the 1/4LNN2 nozzle, there i s no further decrease in drop size above a flow velocity of approximately 1100 cm/sec. This finding, which agrees with the data supplied by the nozzle manufacturer [20], suggests a limiting drop size rather than an indefinitely decreasing drop size as the flow velocity is increased. This is an example of a limit on the applicability of the correlation equations that is found in practice but not always indicated in the literature. 4.3.4 Effect of V iscosi ty on Mean Drop Size The effect of f l u i d viscosity on the drop size of sprays was evaluated in one nozzle, the 1/4LNN2 nozzle. The results are shown in figure 14. These findings show that, as the viscosity increases, the drop size of the spray increases (other factors remaining constant). This is predicted by the correlation equations. Here too there are limits of viscosity over which this effect takes place. Some viscous fluids could not be atomized even at the highest operating pressures attainable in the test apparatus (600 psig). - 48 -Figure 14: Effect of Viscosity on Mean Spray Drop Size. 500 700 1000 2000 3000 5000 FLOW VELOCITY (cm/sec) 10000 Spraying Systems Company 1/4LNN2 grooved-core nozzle. Orifice diameter - 0.0711 cm. - 49 -4.4 Results of Spraying Superheated Water As discussed in section 2.4, the sudden flashing (vapor generation) inside a superheated liquid jet can significantly affect atomization. In the case of a liquid jet issuing from a circular o r i f i c e , i t can shatter the jet to form a spray. A Spraying Systems Company 1/4TT000009 nozzle having an orifice diameter of 0.0203 cm was used to produce a solid liquid jet of water. As is shown in figure 15, this jet was almost completely shattered when the water temperature was increased to 140°C. This concurs with the findings of Brown and York [21], who found that 46°C of superheat was required to completely shatter a 0.0787 cm liquid jet. Although the shattering of liquid jets has been reported in several occasions in the literature [21, 39-43], as described earlier we could find no reported observations on the effect of liquid superheat on sprays from grooved-core nozzles. To determine what may happen in this case, we sprayed water through the five 1/4LNN nozzles described in section 3.2.4 at temperatures above and below i t s boiling point. For each nozzle, the operating pressure was adjusted to make the flow velocity equal in a l l tests. A tabulation of the findings is given in appendix V. They are described in detail below. As the water temperature was progressively increased through i t s boiling point, we observed the formation of a fine mist inside the hollow cone of the spray. As shown in figure 16, the size of this inner core of mist grew as water superheat was increased. We also measured drop sizes in these sprays by sampling at two locations: at the spray Figure 15: Effect of Liquid Superheat on a Simple Water Jet. A l l water sprays made with a Spraying Systems Company 1/4TT000009 nozzle that produces a solid liquid stream. Tests made with water at 50 psig. Temperature: (A) 29°C, (B) 92°C (C) 118°C, (D) 140°C. Figure 16: Effect of Liquid Superheat on Water Sprays Produced from Grooved-Core Nozzles. A l l water sprays are made with a Spraying System Company 1/4LNN2 nozzle operating at 100 ps Temperatures (A) 115°C, (B) 136°C, (C) 155°C. - 52 -cone (the normal sampling point), and at the centerline of the nozzle. The results for the 1/4LNN series nozzles, showing the Sauter mean diameter plotted against water temperature, are shown in figure 17. The drop sizes measured in the cone (zone of major mass flow) of the spray are discussed f i r s t . For the 1/4LNN2 nozzle, the data show a near step increase in drop size when the water temperature i s increased through i t s boiling point. This discontinuity is also present in the case of the 1/4LNN8 nozzle, though on a smaller scale. However, the two largest nozzles do not show any evidence of such a discontinuity. The discontinuity in mean diameter size observed for the 1/4LNN2 nozzle is also apparent in the spray mass distribution. As shown in figure 18, when water i s increased in temperature from 18°C to 85°C, there is a shift in the mass distribution of the spray towards smaller drop sizes. This trend of decreasing drop size with increasing temperature is reversed upon reaching 100°C. Here the distribution shifts to larger drop sizes. A further increase in temperature to 146°C does not drastically alter the mass distribution. As shown in figure 17, the mean drop sizes measured on the spray centerline for the 1/4LNN2 and 1/4LNN8 nozzles are nearly the same at a l l temperatures (d32 = 25.0 ± 2.8 microns). For the two larger nozzles operating below the water boiling point, the drop sizes f a l l in this range. Above the boiling point, the measured drop size increases with temperature. However, for any given temperature, the drop size measured on the spray centerline is always less than that measured in the spray cone. - 53 -Figure 17: Effect of Liquid Temperature on the Mean Drop Size of Sprays Produced by Grooved-Core Nozzles TEMPERATURE (°C) Flow velocity = 851 ± 43 cm/sec. (A) 1/4LNN2, (B) 1/4LNN8, (C) 1/4LNN14, (D) 1/4LNN26. • Sampled from cone of spray . A Sampled from center of spray Equation (9) 54 -Figure 18: Effect of Water Temperature on the Mass Distribution of Sprays Produced by Grooved-Core Nozzles. DROP SIZE (microns) 1/4LNN2 Nozzle, 100-110 psig, Samples taken from cone of spray. Temperatures: (A) 18°C, (B) 85°C, (C) 100°C, (D) 146°C. - 55 -The small droplets described above are not always confined to the center of the spray. Figure 19 shows a drop size distribution sampled from the cone of a superheated water spray from the 1/4LNN2 nozzle. Here, the drop size distribution is clearly bimodal. This indicates that smaller drops may also be present in the cone of the spray. It is not within the scope of this thesis to attempt a definitive explanation of these interesting observations. Our best hypothesis i s that vaporization takes place in the grooves of the nozzle where the f l u i d flows at high velocity (and consequently low pressure). This vaporization may create a two phase flow in the nozzle that could disrupt the nozzle's normal atomization mechanism, thereby producing a coarser spray. Fine droplets may be produced by flashing of individual droplets. These remain largely in the central nozzle area and form the mist observed in the photographs. From the spray tests using heated water, i t is apparent that liquid superheat can introduce significant changes in the character of sprays produced by grooved-core nozzles. The largest effect was observed for the 1/4LNN2 nozzle. To determine i f a similar effect may occur with black liquor, we carried out further spraying tests using black liquor and this particular nozzle. 4.5 Atomization of Black Liquor Above and Below i t s Boiling Point The black liquor described earlier in section 3.4.4 was used in these spraying tests. A liquor solids content of approximately 56% was Figure 19: Number D i s t r i b u t i o n Sampled from the Cone of a Superheated Water Spray. 0.15h O L U PQ o.ioh U l CC 0.05h 0.00 100 150 DROP SIZE (microns) 200 250 Test run 93: 1/4LNN2 nozzle, 105 psig, 127°C, sample taken from cone of spray. - 57 -chosen because i t was fe l t to be the most viscous liquid that could be atomized in the small nozzles. A l l tests were carried out using one nozzle (1/4LNN2) at one operating pressure (200 psig). The liquid temperature was varied from 100 to 136°C - a range which spanned the estimated liquor boiling point of 110°C (see figure I I I - l ) . Duplicate test runs were conducted on the same liquor at a solids content of 56%. The data for these test are tabulated in table V-6. The black liquor spray was found in most respects to be similar in appearance to the hollow cone sprays of water and glycerol/water solutions. However, atomization did not appear to begin Immediately at the orifice; rather a conical sheet formed, which then fragmented into droplets approximately 3 cm from the nozzle or i f i c e . Such an extended sheet is common when viscous solutions are atomized. At the highest superheat used (136°C), a very small mist was observed inside the spray cone. Repeated attempts to sample from this mist failed, suggesting that the droplets were very small. Thus, a l l measurements of drop size in black liquor sprays were taken from the cone of the spray. A comparison of droplet samples taken from sprays of (a) water, (b) 64.8% w/w glycerol/water, and (c) 56.3% solids black liquor at 120°C are shown in figure 20. These tests were a l l made using the 1/4LNN2 nozzle at the same flow velocity of approximately 1350 cm/sec. Figure 21 compares the average Sauter mean diameter from the black liquor tests to the drop sizes of other liquids sprayed in the 1/4LNN2 nozzle. The expected trend of increasing drop size with increasing viscosity at a fixed velocity is evident, as shown in the - 58 -Figure 20: Drop Size Photgraphs from Sprays of Water, Glycerol/Water and Black Liquor. (A) Water, 200 psig, 18°C, pt - lcp (B) 64.8% w/w glycerol/water, 195 psig, 23°C, u - 14.7cp (C) 56.3% solids content West Coast Black Liquor, 210 psig, 120°C, p. - 18.9cp. Magnification - 34.3X. - 59 -Figure 21: E f f e c t of V i s c o s i t y on the Mean Drop Size of Black Liquor Sprays. 2 5 0 I 2 0 0 | 150 100 5 0 01 3 0 0 J L • 2 0 5 cp o 6 8 . 0 cp A 14 .7 cp o I CP A B L A C K L I Q U O R A T 100 ° C AI ~ 3 7 cp ® - B L A C K L I Q U O R I* 100 ° C 2 = 120 ° C 3 = 135 ° C i i 5 0 0 7 0 0 1 0 0 0 2 0 0 0 3 0 0 0 5 0 0 0 F L O W V E L O C I T Y (cm/sec) 1 0 0 0 0 - 60 -previous photographs. As expected, the mean drop size of the black liquor sprays decrease as their velocity increases. In some of the black liquor sprays, the captured drops were not spherical, but rather appeared as deformed spheres and ligaments or cylinders. This phenomenon did not seem to occur for any particular operating condition. An example of this 'poor atomization' is shown in figure 22. While these particles were clearly not spherical, there was no noticable effect on the appearance of the spray. A possible explanation for this phenomenon is that during the i n i t i a l stages of sheet formation, where the sheet thins to the point of ligament formation, the liquor is cooled to a high viscosity such that the surface tension forces cannot pull the ligaments into spheres. The resulting sample then consists of ligaments formed in the early stages of spray formation. It is not clear why this effect was only observed in some cases. The samples that exhibited this 'poor atomization' were not analysed. Most of the black liquor tests yielded spherical droplets, with the Sauter mean diameters from the tests showing a large amount of scatter. As described earlier, such large scatter is expected in spraying studies, and can be attributed to the di f f i c u l t i e s involved in spraying and spray sampling. In our case, an additional source of error was the relatively small number of droplets sampled for some test conditions (see figure II-2). To increase the sample size, the two test runs made under similar conditions were combined to obtain a weighted average of the drop size for three temperature levels: 100°C, 120°C and - 61 -Figure 22: Example of 'Poor Atomization' Found for Some Black Liquor Sprays. Test run 154: Black liquor at 55.2% solids content, Spraying Systems Company 1/4LNN2 groved-core nozzle, orifice diameter = 0.0711 cm, liquor temperature - 133°C, operating pressure = 205 psig. - 62 -135°C. The lower value i s estimated to be approximately 10 degrees below the liquor boiling point (110°C), while the latter is 25°C above. The measured mean diameters for the black liquor sprays are shown in figure 23. An estimate of the error associated with these averaged values was based on the standard deviation of the mean obtained by averaging the individual test points. This error is represented by error bars in figure 23. For comparison, the drop size predicted from correlation equation (9) using the measured properties of black liquor at the test conditions is also shown in the figure. The data curves of figure 23 show several interesting findings. These are summarized in point form below: 1. The measured mean drop size of black liquor sprays are much larger than those predicted by correlation equation (9). 2. Although larger in absolute size than predicted, the dependence of drop size change on temperature change appears to be similar to that predicted by the correlation equation, i.e. lines through the measured and predicted drop sizes have similar slopes. 3. The drop size of black liquor does not show a discontinuous change through the boiling point as did water when sprayed through this nozzle. It is not clear why the measured black liquor drop sizes are so much larger than those predicted by the correlation equation, although i t may be noted that such is also the case for water sprayed through Figure 23: Temperature Dependence of Black Liquor Sprays. i T — i 1 T I 1 I I L I | 80 90 100 110 120 130 140 LIQUOR TEMPERATURE (°C) - 64 -larger nozzles. For black liquor, a possible reason for the observed larger drop size may be the rapid cooling of the liquor when i t is sprayed into a 23°C environment. The liquor cooling increases the liquor viscosity and, as a result, i t is atomized as a more viscous liquid than is thought to be the case. However, extrapolation of the theoretical curve to the level of lower temperature required to produce the measured drop size suggests that the liquor temperature would have to f a l l below room temperature for i t to account for this effect. Thus rapid cooling does not appear to account for the large drop sizes measured in black liquor sprays. While the cause of the larger than predicted size is not clear, i t is evident that the change in drop size with temperature through the boiling point is not discontinuous. Rather, i t is a smooth change, having a slope similar to the slope of the correlation equation. This suggests that the change in drop size with change in temperature can be accounted for by change in viscosity - the only property in the correlation equation to vary significantly with temperature. The nature of the change in drop size with temperature is further i l l u s t r a t e d by the mass-weighted distribution of drop sizes of the black liquor sprays. These are shown in figure 24. It is evident that as the black liquor temperature increases, there is a shift in the distribution to smaller drops. Thus, under the conditions of these tests, i t appears that increasing temperature of black liquor through i t s boiling point does not radically change the Sauter mean diameter of the spray. Rather, i t shifts the drop size distribution slightly towards smaller droplets. -.65 -Figure 24: Mass Distribution of Black Liquor Sprays. O 0 0 CO U J w o w o DROP SIZE (microns) A l l distributions are from tests made with the 1/4LNN2 nozzle at approximately 200 psig. Liquor temperature is given below. A l l samples taken from cone of spray. (A) 100°C (B) 120°C (C) 135°C - 66 -On figure 25, the mass drop size distributions for water, 64.8% w/w glycerol/water solution and 56.3% solids black, liquor at 120°C are compared. It is apparent that the mass distributions of the black liquor and glycerol/water solutions differ markedly, even though both have viscosities of approximately 15 cp. Black liquor has a much greater size distribution, further suggesting that black liquor sprays in a different manner than glycerol/water solution of similar viscosity. - 67 -Figure 25: Mass Distribution of Selected Water, Glycerol/ Water and Black Liquor Sprays. DROP SIZE (microns) A l l distributions are from tests made with the 1/4LNN2 nozzle at approximately 200 psig. (A) Water, 18°C, u - 1 cp (B) 64.8% w/w glycerol/water solution, 23°C, \x - 14.7 cp (C) 56.3% solids content West-Coast Black Liquor 120°C, H - 18.9 cp. - 68 -5. SUMMARY AND CONCLUSIONS The results of this study are summarized below. 1. Prediction of the Sauter mean diameter from correlations published in the literature is subject to large error, as much as 50%. This error is due largely to the dif f i c u l t y in obtaining accurate measurements of spray drop size, specifically in sampling. Other factors may also be important in certain circumstances: differences in nozzle geometry not accounted for by the correlations and limits In the range of applicability of the correlations not specified. 2. Increasing the temperature of water through i t s boiling point was found to drastically change the atomization characteristics of some grooved-core nozzles. In the case of smaller nozzles, this change produced a near step increase in the Sauter mean diameter, as well as a shift in the mass distribution to larger drop sizes. The larger nozzles did not exhibit this drastic change. However, a l l nozzles showed the presence of an inner core of fine mist located on the nozzle centerline when the temperature was increased above 120°C. 3. When the temperature of black liquor was increased through its boiling point, the resulting sprays did not show a near step change in Sauter mean diameter for the nozzle and flow - 69 -velocity where water exhibited this effect. 4. The measured value of mean drop size of black liquor sprays were much larger than those predicted by the correlation equation (9). However, the change in mean drop size with temperature change was similar to that predicted by the correlation equation for the corresponding viscosity change, i.e. the slopes of the experimental and predicted lines were similar. 5. For the black liquor sprays, the mass-weighted drop size distribution was found to be much broader than that found for a glycerol/water solution of corresponding viscosity, sprayed in the same nozzle, at the same velocity. 6. Increased temperature in the black liquor sprays shifted the drop size distribution of the spray towards smaller drop sizes. In conclusion, the findings of these tests indicate that raising of the temperature of black liquor through i t s boiling point does not introduce a discontinuous change in drop size. Rather, the mean drop size decreases in the manner predicted by the correlation equations for the corresponding viscosity change. The distribution of drop sizes i s shifted to smaller diameters. - 70 -6. RECOMMENDATIONS FOR FURTHER WORK Further work on this topic is necessary to fully understand black liquor spraying as i t occurs In a pulp m i l l recovery furnace. The recomendations listed below aim to do this. They f a l l into two general categories: suggestions to make the conditions of the spraying closer to those used in industrial practice and improvements upon the techniques used to measure drop size. 1. Further experiments should be made with black liquors using a higher liquor solids content more typical of recovery furnace operation i.e. 60-70%. In addition, a better simulation of the liquor f i r i n g conditions, e.g. atomizing the liquor Into heated chamber and/or the use of large industrial scale grooved-core nozzles. 2. The major shortcoming of the drop size measurement technique was the extremely long time required to measure the drop sizes. In future, a fully automatic image analysis technique should be employed for this purpose. 3. If extensive further tests are to be carried on, a reappraisal of the drop size measuring techniques should be made. Recent developments In this field may be adapted to the present problem and improve the representativeness of the spray data obtained. - 71 -NOMENCLATURE Unless otherwise indicated here or in the text, cgs units are used thoughout. A nozzle parameter, the ratio of the flow area i n the nozzle or i f i c e to the flow area of the nozzle grooves. D, Do nozzle o r i f i c e diameter. Di inlet diameter of swirl chamber for a swirl hydraulic nozzle. K constant. P di f f e r e n t i a l pressure across nozzle, psig. Q volumetric flow rate. Re Reynolds number = V-T temperature. U, Uo superficial flow velocity through the nozzle o r i f i c e . V tangential velocity component. Va, Vv vertical or axial velocity component. We Weber number = ^ P . a X, Y, Z parameters of equations 11-11 and 11-19. a,b,c,d,e exponents of equation (2). d droplet size. d unspecified mean drop size (see Table I I - l ) . d3 2 sauter mean drop size, the drop diameter having the same ratio of volume to surface area as the entire spray. D^,Q ^ number mean diameter. - 72 -dv,Q 5 volume mean diameter. p, q parameters i n equation II-4. s square-root normal standard d i s t r i b u t i o n . w mass flow rate. x s i z e , or droplet s i z e . x mean size or mean droplet s i z e . a exponent on Reynolds number. B exponent on Weber number equations. Y exponent on nozzle parameter A, equation (7). 9 spray angle. 9FFL maximum spray angle. \x, l i q u i d v i s c o s i t y . ("Apparent v i s c o s i t y " f o r black l i q u o r as described on page 32.) u v i s c o s i t y of gas phase. cS p , p ^ l i q u i d density. p density of gas phase. a surface tension. <j>, ¥ in d i c a t e s f u n c t i o n a l i t y . s ubscripts i denotes siz e or class increment. - 73 -REFERENCES 1. Iran, H.N., Reeve, D.W., and Barham, D., Pulp & Paper Canada, J54 (1), 36 (1983). 2. Chamberlain, R.E., and Cairns C.E., Pulp & Paper Canada, 73_t N: 0 9 (1972). 3. Galtung F.L., and Williams T.J., "An overall control system for the Combustion Engineering recovery furnace," Modelling and Control of  Kraft Production Systems, Proc. Inst. Soc. America, 131 (1975). 4. J u t i l a E.A.A., Uronen, P., Huovinen, N., and Peltola, H. , Pulp & Paper, July, 133 (1981). 5. Sandquist, K., private communication (1982). 6. Nelson, W., "Effects of operating variables on reduction efficiency in the C.E. Kraft Chemical Recovery Furnace," and "Fine spray low bed f i r i n g versus C.E. method," BLRBAC Meeting, October 5, Atlanta, Georgia (1977). 7. V'yukov, B.E., Sb. Tr. VNII Tsellyul Bumayh. Prom. 59, 158 (1971). 8. Merriam, R.L., Richards on, D.L., Grace, T.M., and Taylor, M.L., "Model studies of kraft recovery furnaces," New Process  Alternatives in the Forest Products Industries; Frederick, W.J. Jr. (ed), AIChE Symponium Series, 76_ (1980). 9. Merriam, R.L., TAPPI J., September, 112 (1982). 10. Merriam, R.L., Kraft, Version 2.0, Computer Model of a Kraft  Recovery Furnace, Vol. II: Engineering manual. Report to the American Paper Institute by Arthur D. L i t t l e , Inc. (1980). 11. Kennedy, E.H., Combustion, Nov., 52, (1954). 12. Hochmuth, F.W., TAPPI, 36 (8), 359 (1953). 13. Reiche, H., Papier 2l_ (10), 593; Papier 2A_ (11) 834 (1967). 14. Grace, T.M., "North American recovery boiler explosion experience," International Conference on Recovery of Pulping Chemicals, Sept. 22-25, Vancouver, B.C., proceedings, 127 (1981). 15. Clay, T.M., and Grace, T.M., "Vapor pressure of black liquor at high solids content," Black Liquor Recovery Boiler Symposium 1982, August 31 - September 1, Helsinke, Finland, preprints (1982). 16. Sbderhjelm, L., and Koivuniem, U., "Recent developments in black liquor analysis," Black Liquor Recovery Boiler Symposium 1982, August 31 - September 1, Helsinki, Finland, preprints (1982). - 74 -17. Pilcher, J.M., and Miesse, C.C., Chapter 1, "The mechanism of atomization," Chapter 3, "Design of Atomizers," Injection and  Combustion of Liquid Fuels, Battelle Memorial Institute (1957). 18. Lapple, C.E., Henry, J.P., and Blake, D.E., Atomization - A Survey  and Critique of the Literature, Stanford Research Institute, Menlo Park, Calif., (1967). 19. Marshall, W.R. Jr., Atomization an Spray Drying, AIChE Monograph Series, 50_ (2) (1954). 20. Spraying Systems Company, Drawing No. 11825-28 (1969). 21. Brown, R., and York, J.L., AIChE J. 8_ (2), 149 (1962). 22. Rupe, J.H., "A technique for the investigation of spray characteristics of constant flow nozzles," Third Symposium on Combustion, Flame and Explosion Phenomena, 680 (1949). 23. Spraying Systems Company, Spray Nozzles and Accessories, Industrial Catalog 27 (1978). 24. Weast, R.C. (ed.), Handbook of Chemistry and Physics, CRC press (1976). 25. Perry, R.H., and Chilton, CH. (ed.), Chemical Engineers' Handbook, Edition V, McGraw-Hill (1973). 26. Washburn, E.W. (ed.), International C r i t i c a l Tables of Numerical  Data, Physics, Chemistry and Technology, Edition I, McGraw-Hill (1929). 27. Haake Instruction manuals, Rotovisko RV12, Sensor System MV/SV 400. 28. Sandquist, K., "Rheological properties and evaporation of black liquor at high dry solids content," International Conference on Recovery of Pulping Chemicals, Sept. 22-25, Vancouver, B.C., proceedings, 267 (1981). 29. Kim, H-K., Co, A. and Fricke, A.L., "Viscosity of black liquors by capillary measurements," AIChE Symposium Series, 207 (77), 2 (1981). 30. Jagannath, S., TAPPI 63_(3), 117 (1980). 31. Tate, R.W., and Marshall, W.R., Chem. Eng. Progress, 49_ (4), 169; Chem. Eng. Progress, 49_ (5), 226 (1953). 32. Nelson, P.A., and Stevens, W.F., AIChE J., 1_ (1), 81 (1961). 33. Kim, K.Y., and Saunders, E., "Drop-size distributions from large-scale pressure nozzles," Second Joint AIChE-IIQPR Meeting, May 19-22, Tampa, Florida, preprint 17C (1968). - 75 -34. Wang, K., and Tien, C , Ind. Eng. Chem. Process Des. Develop. 11_ (2), 169 (1972). 35. Turner, G.M., and Moulton, R.W., Chem. Eng. Progress, 49 (4), 185 (1953). 36. Le, C , and Tenisci, T., UBC TRP: Triangular Regression Package, University of British Columbia Computing Center (1978). 37. Bowen, I.G., and Davies, G.P., "Particle size distribution and the estimation of Sauter mean diameter," Shell Technical Report No. ICT/28, October (1951). 38. Dombrowski, N., and Wolfshon, D.L., Trans. Instn. Chem. Engrs. 50, 259 (1972). 39. Lienhard, J.H., and Stephenson, J.M., Trans. ASME, Journal of Basic Engineering, June, 525 (1966). 40. Lienhard, J.H., Trans. ASME, Journal of Basic Engineering, September, 685 (1966). 41. Bushnell, D.M., and Gooderum, P.B., J. Spacecraft and Rockets, 5 (2), 231 (1968). 42. Gooderum, P.B., and Bushnell, D.M., J. Spacecraft and Rockets, 6 (2), 197 (1969). 43. Lienhard, J.H., and Day, J.B., Trans. ASME, Journal of Basic Engineering, September, 515 (1970). 44. Britt, K.W., Handbook of Pulp and Paper Technology, Ed. 2, New York (1970). 45. Smook, G.A., Handbook for Pulp and Paper Technologists, TAPPl/CPPA (1982). 46. Casey, J.P. (ed.), Pulp and Paper Chemistry and Chemical Technology Vol. 1, Ed. 3., New York (1980). 47. MacDonald, R.G. (ed.), Pulp and Paper Manufacture, The Pulping of Wood, Vol. I, Ed II, New York (1969). 48. Whitney, R.P. (ed.), Chemical Recovery in Alkaline Pulping  Processes, TAPPI Monograph Series No. 32, TAPPI, N.Y., (1968). 49. Babcock and Wilcox Company, Steam: Its Generation and Use, Chapter 20, (1955). 50. Giffen, E., and Muraszew, A., The Atomization of Liquid Fuels, London. (1953). 51. Putnam, A.A. et. a l . , Injection and Combustion of Liquid Fuels, Battelle Memorial Institute (1957). - 76 -52. Dombrowski, N., and Munday, G., Chapter 20, "Spray drying," Biochemical and Biological Engineering Science, Blakebrough, N. (ed.), Vol. 2, Academic Press, New York (1968). 53. Pilcher, J.M., Miesse, C.C., and Putnam A.A., Chapter 4, "Spray Analysis" Injection and Combustion of Liquid Fuels, Battelle Memorial Institute (1957). 54. Pearson J.E., and Martin G.E. "An evaluation of raindrop sizing and counting instruments" I l l i n o i s State Water Survey and the University of I l l i n o i s (1957). 55. Matthews, B.J., Wuerker, R.F. and Harrje, D.T., "Small droplet measuring technique", TWR Systems, Calif., Technical report AFRPL-TR-67-295, (1968). 56. Chigier, N., "Drop and velocity instrumentation", 2nd International Conference on Liquid Atomization and Spray Systems, June 20-24, Madison, Wisconsin, proceedings (1982). 57. Tate, R.W., "Some problems associated with the accurate representation of droplet size distributions", 2nd International Conference on Liquid Atomization and Spray Systems, June 20-24, Madison, Wisconsin, proceedings (1982). 58. Mugele, R.A., AIChE J., 8_ (1), 3 (1960). 59. Rydholm, S.A., Pulping Processes, Interscience Publishers, Inc., New York (1965). 60. TAPPI, Technical Information Sheets. 61. Wagoner, C.L., and Vecci, S.J., TAPPI 57 (11), 86 (1974). 62. McDonald, K.L., TAPPI 62 (1), 80 (1979). 63. Hultin, S.O., "Physical properties of Finnish sulphite liquors and black liquors," Proc. of Symposium on Recovery of Pulping Chemicals, May 13-17, Helsinki, Finland (1968). 64. Koorse, G.M., and Veeramani, H., Indian Pulp and Paper, July-June, 21 (1976). 65. Laurola, H., and Wallendahl, U., "Properties of spent pulping liquors," Proc. TAPPI pulping conference (1981). 66. Jagannath, S., TAPPI, 62 (12), 113 (1979). 67. Maksimov, V.F., Bushmelev, V.A., Vol'f, I.V., and Isaeva, S.M., Bumazh. Prom. 11_ (5-7) (1966). 68. Mehrotra, A., and Veeramani, H., Indian Pulp and Paper, August-September, 11 (1977). - 77 -69. Beckwith, W.F., Small, J.D., and Wood, D.A.*, "Surface tension of black liquor," International Conference on Recovery of Pulping Chemicals, September 22-25, Vancouver, B.C. (1981). 70. Kobe, K.A., and McCormack, E.J., Ind. Eng. Chem., 41_ (12), 2847 (1949). 71. Hedlund, A.I., Svenok Papperstidning, 12_, 408 (1951). 72. Han, S.T., TAPPI 40 (11), 921 (1957). 73. Oye, R., Langfors, N.G., Phil l i p s , F.H., and Higgins, H.G., Appita, 31_ (1), 33 (1977). 74. Stenuf, T.J. and Agrawal, M.L., "Viscosity of black liquor," AIChE 89th Annual Meeting, August 17-20, Portland, Oregon, Paper 29d, (1980). 75. Davis, D.S., Paper Industry, Feb., 1097 (1955). 76. Harvin, R.L., A Study of the thermal and physical propeties and  heat transfer coefficients of sulfate paper mil l black liquor, PhD Thesis, University of Florida (1955). 77. Lengyel, P., "Investigation and technical experiences in the recovery of straw black liquor," Proc. of Symposium on Recovery of Pulping Chemicals, May 13-17, Helsinki, Finland (1968). 78. Lankenau, H.G., and Fores, A.R., Pulp and Paper Canada, January, 63 (1969). 79. Moser, C , The viscosity of concentrated black liquor, BASc thesis, University of British Columbia (1980). 80. Karoly, J.A., Pulp and Paper, Nov., 110 (1981). 81. Korpio, E., and Virkola, N.E., "The effect of cooking variables and wood raw material on the properties of black liquor," Black Liquor Recovery Boiler Symposium 1982, August 31-September 1, Helsinki, Finland (1982). 82. Liem, A.J., "A simple viscometer for spent liquor," International Conference on Recovery of Pulping Chemicals, Sept. 22-25, Vancouver, B.C. (1981). 83. Sadawarte, N.S., Dharwadkar, A.P., and Veeramani, H., "Pulp strength properties and black liquor viscosity for kraft pulping of bamboo-bagasse blends (70:30)," TAPPI Pulping Conference, October 25-27, Toronto, Ontario (1982). 84. Smith, A.R., private communication (1983). - 78 -APPENDIX I KRAFT PROCESS AND RECOVERY FURNACE OVERVIEW 1. The Kraft Process The kraft process is an important chemical pulping process that produces a strong pulp with minimum damage to the pulp fibers. In the kraft process, the desired cellulose and hemicellulose wood components making up the wood fibers are chemically separated from the undesired lignins and other extraneous wood components. A typical kraft pulping process w i l l remove about 50% of the wood mass. The spent materials -the dissolved wood and exhausted cooking chemicals - are recovered and processed through a recovery cycle that regenerates the cooking chemicals and recovers the energy value of the wood components. This cyclical and interrelated process is illustrated in figure 1-1. A brief description of the chemical reactions and process steps involved in the kraft cycle is presented below. Although the kraft process is an intricate chemical process that varies from mill to m i l l , the overall process steps remain the same. More detailed information about the kraft process can be found in the following reference texts [44-47]. The kraft cycle begins with the cook or digestion process. Wood chips are reacted with an aqueous cooking liquor composed of NaOH and Na2S under high temperature and pressure. This reaction takes place in batch or continuous mode in reactors called digesters. The cooking solution (white liquor) selectively reacts with the lignin, making i t Figure 1-1: Diagram of the Kraft Process. WHITE LIQUOR Na2S, NaOH WOOD CHIPS> DIGESTER LIMESTONE CaCO, BLOWTANK GREEN LIQUOR STORAGE GREEN LIQUOR. CURIFIER PULP' PULP WASHER \ B L 1 7 - 20 % \ EVAPORATOR DREGS WASHER 45 - 55 « * S B I -4 5 " * STORAGE- RECOVERY ' FURNACE 60 - 70 % WBL » Weak Black Liquor SBL = Strong Black Liquor * = Black Liquor Solids Na2S04 1 CaC03 •+ CaO + C02 2 CaO + H20 ->• Ca(OH)2 3 Ca(0H)2 + Na2C03 2NaOH + CaCO, Table 1. Baalc racovary-bollar raaclioni arc shown In almpllliad aqualiona R . d u c l n g s o n * Na,SO. Na,SO, Na,SO, 2C + 2CO + CO, + C + C + 2H, + 2C + 4C + C O, O, C H,0 2H, + 0 , • Na,S + 2CO, • Nafi + 4CO - Na,0 + SO, + • 2C0 • 2CO, • 2CO - CO + H, - CH. • 2H,0 Drying zona Na,S + CO, + H,0 Na,0 + CO, CH. + H,0 Na,C0, + H,S Na,C0, CO + 3H, Oxid iz ing z o n a N J , C O , + S O , 2Na ,S + 30, N a , C O , + S O , 2CO + O , • Na,SO. + CO, • 2Na,CO, + 2SO, - CO, + Na,SO, - 2CO, [4] - 80 -soluble ln the cooking liquor. After the cook, the cooking liquor, spent of its active components, is black in color due to the dissolved wood components. This black liquor is separated from the pulp In a counter current washing cycle. The washed pulp, a light brown in color, is then ready for further processing, depending on Its end use. After the washing cycle, the black liquor has been diluted to 16-18% solids content (see definition in section III-3). It Is then concentrated to 60 to 70% in two stages. It is f i r s t concentrated to 45-55% solids in multiple effect evaporators, and then to 60-70% solids using sensible heat from the recovery boiler flue gases. The black liquor is then sprayed into a recovery furnace where further evaporation and combustion of the dissolved wood components takes place. The heat recovered from the liquor combustion is used to generate steam for the m i l l . The spent cooking chemicals are reduced in the furnace by a complex set of reactions, which may be simplistically expressed by: Na2S0it + 2C •»• Na2S + 2C02 (1-1) As a result of these reactions, a molten smelt consisting of Na2S and Na2C0 3 is produced in the base of the furnace. This smelt is removed from the furnace and dissolved In water to form a solution of Na2C03 and Na2S (green liquor). In the subsequent recausticization step of the kraft process, the Na2C03 is converted to the desired NaOH by reaction with Ca(0H)2 as follows: - 81 -Na2C03 + Ca(0H)2 t 2NaOH + CaC03 (1-2) The CaC03 formed i n this reaction i s removed from the liquor by c l a r i f i c a t i o n and Is burned i n a lime k i l n to regenerate CaO used to make more Ca(0H)2 (Slaking). The c l a r i f i e d l i q u o r , containing NaOH and Na2S, i s now the white liquor used to pulp wood. Here the cycle s t a r t s again. 2. The Recovery Furnace 2.1 Introduction The recovery furnace i s the largest single piece of equipment i n the k r a f t m i l l . I t f u l f i l l s the important roles of producing pulping chemicals and process steam by the combustion of black l i q u o r . These along with other important objectives of recovery furnace operation are described below: Recovery of Pulping Chemicals: As described e a r l i e r , the k r a f t process uses a cooking liquor composed of NaOH and Na2S. In the recovery furnace the f i r s t step i n recovering these chemicals from a completed cook occurs - the regeneration of the sulfur compounds i n the black liquor as Na 2S. These reactions (represented by equation 1-1) takes place largely i n the char bed of the furnace i n a reducing atmosphere. The e f f i c i e n c y of the conversion i s measured by the reduction r a t i o : - 8 2 -Na2S Reduction ratio = -—„ , „ — — - (1-3) Na2S + Na2S0it v ' where the chemical quantities are represented on a molar basis. From the operational standpoint, i t is desirable to have as large a reduction ratio as possible, i.e. a minimum of Na2S0if The Na2S0it does not contribute to the pulping and is therefore considered a "dead load" that is carried around the chemical cycle. Typical reduction ratios are around 0.90 to 0.95. Production of Steam: The combustion of the organic solids present in the liquor releases a large quantity of heat. This heat is used in the furnace to further evaporate the black liquor and to generate process steam. The amount of steam generated makes an important contribution to the overall mill energy balance. High steam production requires efficient liquor combustion and clean heat transfer surfaces in the boiler heat exchanger. Minimization of Particulate and Gaseous Emissions: In the recovery furnace, particulate and gaseous compounds that can escape with the flue gases are formed. The particulates are primarily Na2S0j + and Na2C0 3« The gaseous compounds include CO, SO2, H2S and small quantities of highly odiferous sulfur compounds. From the environmental standpoint i t Is desired to reduce these emmissions as much as possible, which can be done to some extent by manipulation of certain furnace operating variables, e.g. the coarseness of the liquor spray. Safety: In the process of chemical recovery a smelt bed is - 83 -generated i n the base of the recovery furnace. I f water or d i l u t e liquor comes i n contact with this molten smelt, violent generation of steam, referred to as smelt/water explosions, can occur. Such an explosion can extensively damage the furnace and poses a threat to the safety of operating personnel. This fact necessitates close monitoring of the furnace operation, i n p a r t i c u l a r the spray liquor s o l i d s content. 2 . 2 Recovery Furnace Operation One of the more important steps involved i n recovery furnace operation i s the spraying of black liquor into the furnace. This aspect of recovery furnace operation i s the topic of this thesis and i s therefore discussed i n d e t a i l below. Discussion of other aspects of furnace operation may be found i n a number of texts and publications, for example see [2, 47-49]. In North America today there are two major types of recovery furnaces i n use - the Combustion Engineering Furnace and the Babcock and Wilcox furnace. Major differences between these furnace designs include the manner i n which liquor and a i r are Introduced to the furnace and are discussed below. 2 . 2 . 1 Combustion Engineering (CE) Furnaces In the CE furnace, black liqu o r i s evaporated and burned i n suspension. To achieve this the liquor i s f i r s t atomized using - 84 -grooved-core nozzles (illustrated in figure 1-2) and introduced to the furnace at the fi r i n g gun level (shown in figure 1-3) using oscillating liquor guns. Combustion air is introduced in the CE furnace in two zones: - the primary zone just above the char bed where approximately 65% of the total air is added; and the secondary zone, above the liquor guns where the remaining air is added in a tangential manner to promote intense mixing of the gases, thus completing the combustion process. Although recovery furnaces differ in design from installation to installation, the one shown in figure 1-3 is typical of a number of recovery units. In figure 1-3 the major pieces of operating equipment have been Identified. 2.2.2 Babcock and Wilcox (B & W) Furnaces In the B & W furnaces, black liquor is sprayed on to the furnace walls by an impringment (splash plate) nozzle, see figure 1-2. Liquor evaporation occurs on the furnace walls, with the dried liquor sloughing off and fa l l i n g to the char bed. Air is introduced in three areas in the B & W furnace. Approximately 45-55% of the total air is added in the primary zone just above the char bed and is used to control the shape of the bed. A further 20-35% of the total air is introduced between the primary zone and the liquor gun level, creating a secondary zone to control the wall drying and further adjust the char bed height and shape. The remaining air is added above the liquor nozzles in a tertiary zone to complete the combustion process. - 85 -Figure 1 - 2 : Nozzles Used for Black Liquor Firing in North American Recovery Furnaces. (A) CE furnace nozzle (B) B & W furnace nozzle Scales in centimeters. - 86 -Figure 1-3: Schematic of a Combustion Engineering Recovery Furnace. - 87 -2.2.3 Black Liquor Firing The spraying of black liquor is of fundamental importance to the operation and control of a recovery furnace. If the size of the liquor droplets in the spray is too small, they w i l l be entrained by the combustion gases and carried upwards in the furnace. If this size is too large the droplets w i l l have too small a surface/volume ratio and w i l l f a i l to sufficiently evaporate before reaching the char bed. This latter factor is of particular importance to a CE furnace which relys upon suspension firing of the liquor. The B & W furnace operation is not as sensitive to variation in spray drop size; the strategy of wall drying requires only that control on the small end of the drop size distribution be maintained - to prevent carry over. This review w i l l concentrate on suspension drying and burning of black liquor; however, many of the points to be discussed are equally valid for wall drying operation. There are two extreme conditions of black liquor sprays: fine sprays and coarse sprays. These are examined below along with the problems in furnace operation that result. Fine Spraying of Black Liquor CE furnaces are sometimes operated using a fine black liquor spray (less than 1/4 inch expanded particle diameter) caused by either too high a liquor temperature and/or pressure [6]. This results in a number of problems. First, there is increased carryover of particulate matter which leads to increased fouling of heat exchange surfaces and - 88 -places a greater load on the electrostatic precipitator. The former necessitates increased soot blowing and/or more frequent outages for thorough cleaning of the c r i t i c a l ash-accumulating sites in the boiler. The latter increases the recycle of dead load chemicals through the recovery cycle.* Secondly, fine spraying reduces the amount of liquor brought to the char bed, which can result in formation of a shallow char bed. These conditions decrease reduction efficiency, and increase the deadload Na2S0it recycled through the kraft process. Thirdly, fine spraying causes the upper areas in the boiler to heat up [4] which can lead to conditions where soot blower resistent deposits are formed [1]. Other problems are encountered with fine liquor spraying, including increased H 2 S , mercaptan and SO2 emission, decreased liquor burning stability and increased fireside corrosion of waterwall tubes have been documented by Nelson [ 6 ] . Very Coarse Spraying of Black Liquor Although the correct drop size for black liquor sprays is commonly described as being coarse [ 6 ] , eventually a point occurs when the droplets become so large that insufficient evaporation takes place before the liquor droplets reach the char bed. This excess moisture must be evaporated, which removes heat from the char bed. The resulting decrease in bed temperature adversly affects the reduction efficiency and can result in a condition known as a "brown out," a localized cooling of the char bed. If the bed temperature f a l l s too far, •Captured particulate matter is returned to the black liquor and is therefore fired again. - 89 -i n s u f f i c i e n t heat i s present to maintain combustion. The heat present continues the evolution of pyrolysis gases which may form pockets in the furnace. If one should suddenly i g n i t e , the r e s u l t i n g explosion could rupture a wall tube and r e s u l t i n a second more vi o l e n t smelt/water explosion. While the above discussion has been concerned with a single drop s i z e , any spray produced by a nozzle has a d i s t r i b u t i o n of drop s i z e s . Thus any spray i s l i k e l y to have extremes which f a l l into the categories of "coarse" or " f i n e " sprays as described above. Therefore, a desirable operating point i s one where stable operation with a maximum of steam production and reduction e f f i c i e n c y and a minimum of p a r t i c u l a t e carryover i s achieved. - 90 -APPENDIX II LITERATURE REVIEW OF ATOMIZATION IN GROOVED-CORE NOZZLES 1. Introduction Atomization is the subdivision of a continuous liquid jet into a spray consisting of a large number of droplets. This subdivision produces a considerable increase in surface are of the liquid, and therefore is an important means for obtaining high mass and/or heat transfer between liquids and gases. For this reason atomization is commonly used in drying, evaporation, and combustion processes. Atomizers are usually classified by two c r i t e r i a : the energy source used to atomize the liquid and the shape of the resulting spray. Most atomization techniques use hydraulic, pneumatic, or centrifugal energy sources to produce sprays with a hollow cone, f u l l cone, or f l a t spatial configuration. The liquid to be atomized and the characteristics required of the spray w i l l determine which atomizer is best suited for the task. The performance of atomization devices are described by four key parameters: 1. mean size and size distribution of the droplets in the spray, 2. energy required for atomization, 3. volumetric flow capacity of the device, and 4. special operational considerations, such as erosion and clogging. - 91 -While a l l of these are important, the mean drop size and drop size distribution i s most important in light of the objective of atomization. This review examines the published literature of one type of atomizer - the gooved-core hydraulic nozzle. Emphasis is placed on published findings of drop sizes produced in sprays from these nozzles and the dependence of this drop size on key liquid properties. For a general overview of atomization and spraying processes, a number of references can be consulted [18, 19, 50-52]. 2 Mechanism of Jet Breakup A l l atomization techniques involve the disruption of the st a b i l i z i n g forces within the liquid by the application of internal or external forces. These forces initate i n s t a b i l i t i e s which result in fragmentation of the liquid. After dissipation of the disruptive forces, the liquid fragments form spheres under influence of surface tension forces. The detailed steps in the atomization process have been summarized by Lappel et. a l . [18] as: 1. The extension of the bulk liquid into sheets, jets, films or streams by acceleration of the liquid. 2. The i n i t i a t i o n of small disturbances in the liquid in the form of ripples, proturbances, or waves. 3. The formation of short ligaments on the liquid surface as a result of f l u i d pressure or shear forces. - 92 -4. The collapse of the ligaments into drops as the result of surface tension. 5. The further breakup of drops as they move through the gaseous medium by the action of fluid pressure or shear forces. Some or a l l of the above steps may be important in a given atomization process. For atomization by grooved-core nozzles, distrubances are initated by the imposition of directional changes on the fluid as i t moves through the nozzle. The liquid emerges from the nozzle as ligaments or sheets which rapidly collapse into droplets. This process is extremely rapid, so much so that in many cases the spray forms immediately at the orifice. Several theoretical analysis have been attempted to explain the atomization process by rigorous hydrodynamic analysis [17], While these theoretical studies have improved our understanding of the atomization processes, they apply to circumstances far to idealized to be used for quantitative prediction of spray drop size in commonly used nozzles. Most equations in the literature which yield this type of quantitative prediction have been derived from experimental data, and are presented in the form of correlations of dropsize with nozzle geometry, operating conditions and liquid properties. Often the variables in these correlations are grouped as dimensionless parameters. 3.0 Dimensional Analysis of Atomization Phenomenon A number of dimensional analyses of atomization phenomenon are - 93 -given in the literature [18, 50]. The use of this approach greatly simplifies the development of experimental correlations for predictive purposes. In the case of liquid atomization, the many variables which govern this process may be grouped Into three categories: 1. The nozzle type and the nature of the flow at the ori f i c e , 2. The physical properties of the discharging fluid, and 3. The properties of the medium into which the fluid is discharged. While dimensional analyses can be applied with equal validity to any number of atomization processes, the solution presented here is developed for atomization in grooved-core nozzles under the experimental conditions studied in this thesis. For other situations some of the simplifying assumptions made may not be valid. The mean drop size diameter can be expressed as a function of many variables, d ^ - T (D, U, pv p g, a, u A, u g, 0) (II-l) where D is a characteristic dimension of the nozzle, usually the ori f i c e diameter, and U is a characteristic of the jet velocity, more properly the relative velocity between the liquid and gas phases, but usually for simplicity the superficial discharge velocity. By applying the principles of dimensional analysis, one solution of equation (II-l) i s : - 94 -d *'(Re, We, P j l/p g, u^/Ug, 9) (H-2 ) For the atomization of l i q u i d s into ambient a i r , the gaseous properties p and u w i l l be constant, and the terms P 0 / p and H 0 / u _ drop from equation (II-2). The spray angle, 6, can be treated i n a number of ways. Some authors use i t to describe the r a d i a l and a x i a l components of the l i q u i d v e l o c i t y at the o r i f i c e , while others did not observe any dependence of the spray angle on the drop size and do not include i t i n their c o r r e l a t i o n s . If the spray drop size i s independent of 9, equation (II-2) can be further s i m p l i f i e d to: d y = K R e a WeP (II-3) 4. Drop Size Distributions i n Sprays 4.1 Characterization of Sprays A l l nozzles y i e l d sprays having a d i s t r i b u t i o n of drop s i z e s . To characterize the spray drop s i z e , i t i s necessary to choose appropriate s t a t i s t i c a l parameters to represent the mean drop size as well as i t s d i s t r i b u t i o n . The major requirement, however, i s to define some form of mean drop s i z e . There are a number of ways of defining the mean drop size of a - 95 -spray. The specific mean chosen in any particular case is determined by application. Some possible mean diameters are listed in table I I - l along with a brief description of their usual application. These statistics are computed from the spray distribution using the equation given below: n E • d q-p d = fi=* } qp n E • d 1=1 i i where fy^ is the fraction (weight or number) of particles in the i size interval having mean diameter d^« One cannot directly compare size distributions described by different mean diameters. This fact is shown in figure I I - l where the different mean diameters calculated for a spray drop size distribution are shown along with the original number distribution. A complete description of a spray is given when the distribution as well as the mean drop size is specified. To achieve this, some investigators have chosen empirical distribution functions that require estimation of two or three parameters from experimental data. Others have used standard distributions such as the log normal or square-root normal functions. The square-root normal distribution has been found to describe spray drop size data well [31-34] . This distribution is given below: - 96 -Table I I - l Mean Diameters Used to Describe Sprays Mean Diameter Symbol Field of Application Linear or arithmetic Surface djo evaporation, comparisons d 2g adsorption, or other processes where the surface area is controlling Volume Surface diameter Volume diameter Volume-surface or Sauter mean d3Q comparison of the mass distribution of a spray d 2 i adsorption d 3 1 evaporation, molecular diffusion d 3 2 efficiency studies, mass transfer, reaction Figure I I - l : Comparison of the Number Dist r i b u t i o n and Mean Diameters of a Typical Spray. 800 700 600 500 o o 400 300 200 100 1 1 1 1 1 1 1 1 1 r 1 23 4 5 6 7 1 Yo.5 NUMBER MEAN -2 d g GEOMETRIC MEAN 3 dio ARITHMETIC MEAN — 4 d20 SURFACE MEAN 5 d30 VOLUME MEAN 6 d32 SAUTER MEAN -7 dV,0.5 MASS MEAN JL _l_ VO 0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 DROP SIZE (microns) 160.0 180.0 200.0 - 98 -f(x) -s/2~7t 1 expf (H-5) 4.2 Measurement of Spray Drop Size As described earlier, most of our fundamental knowledge of spray drop size has been obtained by experiment. Accordingly, much effort has been spent developing suitable techniques for measuring drop sizes in sprays. Many techniques have been developed; each has advantages and disadvantages, and none is completely satisfactory. There are two basic approaches for obtaining drop size information from a spray: (1) measurement of the droplets that pass through a plane during a given time interval (temporal sampling); and (2) measurement of the droplets present in a volume of space in a given instant (spatial sampling). Excepting the special case where a l l droplets have the same velocity and direction, the two methods give different results. Another factor involved in measuring the spray is the technique used to sample the droplets. Direct sampling, i.e. where the spray droplets are physicaly captured, poses problems of withdrawing a representative, unaltered sample from the spray. Indirect sampling, where the spray drops are photographed or measured by optical methods, can Introduce other errors such as spatial resolution. In addition, different sampling methods can yield a number or weight distribution of - 99 -the drop sizes in the spray. A extensive discussion of the many spray measuring techniques available is beyond the scope of this thesis. Such information can be found in a number of sources in the literature, for example references [53-56]. The main point to be noted from this discussion is that many different measuring techniques, mean diameters, and distribution functions have been used by workers in the past to describe sprays. This makes comparison of findings reported in the literature very d i f f i c u l t , i f not impossible. 4.3 Problems Involved With Accurate Determination of Spray Drop Size There are a number of problems associated with the accurate determination of spray drop size distributions. One discussed previously is the sampling technique. Other problems involve sampling procedures, including incorrect sampling location, and the instrumentation used. These are summarized and discussed in an art i c l e by Tate [57]. One major problem in sampling is to ensure that enough droplets are measured that a meaningful mean droplet size is obtained. This problem was addressed by Bowen and Davies [37] who experimentally measured the error of estimating the Sauter mean diameter from a known population of drops when various sample sizes were taken. Their results indicated that 5500 drops had to be measured to obtain a sample mean accurate to within five percent of the population mean, while 35,000 - 100 -drops were required to be within two percent. Their findings are shown in figure II-2. Bowen and Davies commented that these values were likely maximum error limits and that actual measurements would give a better representation of the true mean drop size. 5. Studies of Grooved-Core Nozzles As reported earlier, the grooved-core nozzle is of special interest in this study. It is therefore discussed in some detail below. The grooved-core nozzle takes its name from the helically-grooved insert that imparts a swirl notion to the liquid upstream of the nozzle or i f i c e . This swirl motion produces a spray with a characteristic hollow cone. The main mass flow of the liquid is within this outer conical ring, but the mass distribution becomes more uniform as the distance from the nozzle is increased [50]. Previous investions of grooved-core nozzles have produced a number of correlations for mean drop size. Some of these applied to specific nozzles, while others were intended to apply to the generic class of nozzle of which the grooved-core nozzle is a member. The various correlation equations presented in the literature for grooved-core nozzles are discussed below. 5.1 Turner and Moulton (1953) Turner and Moulton [35] studied commercial grooved-core nozzles (Spraying Systems Company 1/4LN and 1/8A) spraying organic materials - 101 -Figure II-2: Estimated Error of Sauter Mean Diameter Based on Sample Size. 100,000 I 1 p 1 1 PERCENT ERROR After Bowen and Davies [ 3 7 ] . - 102 -that solidified well above room temperature. The material was liquidified by heating and sprayed. The atomized droplets solidified as cooling occurred, and were then collected and measured. A characteristic mean size defined by: ., — E n x 3 log x log x - 3^— (II-6) E n x was used to describe the spray distribution. The findings gave the following correlation for the 1/4LN nozzle: - , , . ,1.520 -.444 0.713 0.159 ,__ ... x (microns) = 16.56 D w a \i (II-7) where w is the flow rate in g/s and the other quantities are in cgs units. For our purposes, equation (II-7) can be rewritten as: - . _0.632 TT0.444 0.444 0.159 0.713 / T T Q , x = 0.127 D U p \i a (II-8) The large exponent for surface tension (0.713) shows strong dependence of mean drop size on this liquid property, in contrast to the weaker dependence found by other investigators (typically 0.2 to 0.3). Turner and Moulton fitted their data to the log normal distribution function and used an adjustment factor to account for the - 103 -sampling losses of small drops. To facil i t a t e correlation of the data, the nozzle orifice diameter alone was used to describe the nozzles even though other geometric differences existed among them. This practice is commonly used by investigators in this f i e l d . 5.2 Tate and Marshall (1953) Tate and Marshall [31] studied the atomization of water in Spraying Systems Company grooved-core nozzles. They sampled drops in an immisible liquid collector. The drops were then photographed and measured. In deriving their correlation, Tate and Marshall concentrated on three variables they f e l t to be of fundamental importance: the nozzle orifice diameter, and the axial and tangential velocity components of the liquid emerging from the o r i f i c e . The liquid velocity components were calculated from knowledge of the nozzle geometry and the assumption that the orifice ran f u l l . The correlation they obtained i s : d 3 2(microns) « 286(0.394D + 0.17) exp{ ° -3.08 x 10 Vt} (II-9) v where D, the orifice diameter is in cm, and V v and Vt, the liquid velocity components are in cm/sec. While only water was used to obtain this correlation, t r i a l runs with viscous liquids demonstrated that increased liquid viscosity produced a sharp increase in the drop size as - 104 -well as a decrease i n spray uniformity. 5.3 Mugele (1960) Mugele [58] analyzed atomization i n hydraulic nozzles using data a v a i l a b l e i n the l i t e r a t u r e supplemented with photographic measurements of some sprays. He r a t i o n a l i z e d that every nozzle produces a maximum drop s i z e , and f i t t e d the observed spray d i s t r i b u t i o n s to an empirical function requiring the s p e c i f i c a t i o n of three parameters: the mean drop s i z e , the variance of the d i s t r i b u t i o n , and the upper size l i m i t of the drops. He recommended the following c o r r e l a t i o n for the grooved-core nozzle: I t i s i n t e r e s t i n g to note that Mugele recommends this c o r r e l a t i o n for other atomization devices in addition to the hydraulic swirl nozzle. 5.4 Nelson and Stevens (1961) 5.0 Re -0.35 f\iV a •0.20 (11-10) Nelson and Stevens [32] studied the atomization of water and organic l i q u i d s i n Spraying Systems Company type SL spray drying nozzles. The spray was sampled by freezing the droplets in l i q u i d - 105 -nitrogen. They then screened and weighed the size fractions and correlated their data using the square-root normal distribution. They found their water data to be correlated by: where Y = -0.144 Z 2 + 0.702 Z - 1.260 (II-lla) Y = l o g i o ^ r T ^ (II-llb) Z - log l o [Re(ff) 0- 2 0 (l^) 1- 2 0] ( I I - l l c ) Lappel [18] has shown that this can be correlated as: 0, n n0.47 0.42 0.11 . 23,0* K 2 _ ( / em-,0.64 TI0.60 0.53 (.tan - j ) U p where dy^o.5 ^3 t n e volume mean diameter. Nelson and Stevens also present a graph for obtaining the Sauter mean diameter from the volume mean diameter and square-root normal standard distribution of the spray. The authors developed two separate correlations - one for water and another for organic liquids. They offered no explanation for this. - 106 -It is possible that factors other than the physical differences between water and the organic liquids may have accounted for this. 5.5 Lappel, Henry and Blake (1967) This study c r i t i c a l l y reviewed and evaluated published findings in the fi e l d of atomization prior to 1966 [18]. Their literature review covering 955 pertinent references is the most comprehensive summary of atomization work to date. For hydraulic swirl nozzles, these authors derived a correlation which gave best agreement between the data (weighted average) of various investigators. This correlation is given below: d32 -0.20 -0.25 ,__ —-— = 5.5 Re We (11-13) The authors found the error of the above correlation to be large: ±50%. They attributed most of this to differences among the drop size analysis techniques used by different investigators, particularly spray sampling. 5 .6 Kim and Saunders (1971) Kim and Saunders [33] carried out an experimental investigation of swirl nozzles with orifice diameters up to 3.96 mm. They used a sampling technique in which a representative sample of spray was captured, frozen in chilled petroleum ether, and then screened. - 107 -They found the drop size distribution of these sprays to be square-root normal, and presented two correlations for the mass median diameter. The f i r s t was based on the axial and tangential velocities (in ft/sec): ^ m 5 (microns) = 7670 0??l'"o.40 ( I I " 1 4 ) Va Vt with Do (the orifice diameter) expressed in inches. The second equation was based on the nozzle geometry: 0.95 n,0.80 dy Q 5(microns) = 16900 ^ — (II-15) where D^  is the diameter of the nozzle swirl chamber inlet, in inches, and Q is the volumetric flow rate, USGPM. Kim and Saunders found that other investigators' data could be correlated by these equations i f the constant was changed. They concluded that this constant depended on nozzle geometry. However, i t could also depend on differences in spray sampling among investigators. 5.7 Dombrowski and Wolfshon (1972) Dombrowski and Wolfshon [38] carried out investigations on a series of commercial swirl spray nozzles, some of which were of the - 108 -grooved-core type. Atomizing water over the range of 1 to 725 US gal/hr and at pressures ranging from 50 to 500 psig, they found the drop sizes to be smaller than those reported by other investigators, and independent of nozzle design. Their data were correlated well (+14% to -12.5%) by the following equation: where Q is in US gal/hr and Uo in ft/sec. No dependence of the drop size on spray angle was found. Their data were also correlated well by: where P is the pressure drop across the nozzle, psig. These correlations were derived from drop sizes measured by the Sauter light absorption technique which only gives the Sauter mean diameter of the spray. To obtain size distributions they supplemented this study by photographing sprays from selected nozzles. The distributions were found to be best described by the square-root normal distribution. A correlation for the square-root standard deviation was also given. d,„(microns) = 3305 (11-16) d,0(microns) = 332 (11-17) - 109 -5.8 Wang and Tien (1972) Wang and Tien [34] studied the atomization of non-Newtonian fluids in grooved-core nozzles. The drops were frozen, then collected and seived. They proposed a correlation of the form: d -j?L = 7(Re, We, A) (11-18) where A is the ratio of the orifice area to that of the grooved slots. Their study showed that the correlation was valid i f the viscosity used was the liquid viscosity at the shear rate in the nozzle. Their correlation, based on 210 sets of data (their own combined with Nelson and Stevens' data for organic fluids) is given below Y - -0.60 X + 1.40 (II-19a) where Y = l o g 1 0 (^ 4^ -) (II-19b) and i /„ °«40 „ 0.52 ,0.30. , „ , n v X = logio(Re We A ) (II-19c) - 110 -This correlation can be rewritten to: ty± = 25.1 Re" 0' 2 4 0 We"'312 A' 0' 1 8 0 (11-20) 6* Comparison of Grooved-Core Nozzle Studies The published findings on atomization from grooved-core nozzles described thus far show the following: 1. Different mean drop sizes are used by different investigators, 2. A wide range of correlations are used to predict spray drop size, 3. The dependence of mean drop size on nozzle geometry, operating conditions, and liquid properties differs among the various investigators. Thus, the current state of knowledge does not definitively indicate which correlation, i f any, can accurately, or even adequately, represent the process of atomization in grooved-core nozzles. It is likely that each of the correlations is suitable in the particular experimental conditions under which i t was investigated. Nevertheless, to obtain some form of general picture of the dependence of spray drop size on key spray variables, we attempted to compare a l l the published correlations on a common basis. This was achieved in two ways. First, a comparison was based on rearranging each investigators' correlation in the following form: - I l l -= K D a U b p c | i d a e (II-21) Table II-2 gives the dependence of the mean drop size found by each investigator on the fundamental spray properties given i n equation (11-21). Here most investigators found similar magnitude for the powers a,b,c... representing the powers of the i n d i v i d u a l variables a f f e c t i n g the spray. The values suggested by Lappel et. a l . [18] are average values based on those reported i n the l i t e r a t u r e prior to 1966, and give a good i n d i c a t i o n of the l i k e l y dependence of mean drop size on each v a r i a b l e . The nozzle o r i f i c e diameter and flow v e l o c i t y c l e a r l y have the largest e f f e c t on spray drop size, while the other variables have lesser e f f e c t s . The dependence reported for surface tension varies widely among authors. This i s l i k e l y due to the limited range over which i t can be varied experimentally. A second comparison was made and i s shown i n figure II-3. Here, the correlations found i n the l i t e r a t u r e predicting the Sauter mean diameter of grooved-core nozzles are compared using one p a r t i c u l a r nozzle as a basis. The correlations were evaluated for water atomization into a i r at 23°C using the Spraying Systems Company 1/4LNN2 grooved-core nozzle (described i n section 3.2.4). In making this comparison, the l i m i t s for each c o r r e l a t i o n s p e c i f i e d by the author were taken into account. Where no l i m i t s were s p e c i f i e d , the range of v e l o c i t y over which this nozzle was found to operate i n our experiments was used. TABLE 1 1 - 2 SUMMARY OF DEPENDENCE OF VARIABLES ON THE MEAN DROP SIZE PRODUCED  BY SWIRL JET NOZZLES Year I n v e s t l g a t o r ( s ) and R e f e r e n c e Power Dependence of Mean Drops I ze on I n d i c a t e d V a r i a b l e Comments N o z z l e O r i f i c e D tameter V e l o c i t y L i q u i d D e n s i t y p L i q u i d V i s c o s i t y * S u r f a c e T e n s i o n a 1943 Longwel l [18] 1.00 - 0 . 7 5 - 0 . 3 7 5 1949 19S3 J o y c e (18] 0 . 5 0 - 0 . 8 - 0 . 6 0 . 2 .1953 T u r n e r ft M o u l t o n [35] 0 . 6 3 2 0 . 5 1 5 - 0 . 4 4 4 - 0 . 5 3 7 - 0 . 4 4 4 - 0 . 5 3 7 0 . 159 0 . 2 2 0 0 . 7 1 3 0 .594 -G rooved Core N o z z l e s - T a n g e n t i a l N o z z l e s 1954 1955 R a d c l l f f e [18] O . 5 0 to 0 . 6 3 6 - 0 . 5 5 to - 0 . 7 4 2 - 0 . 15 to - 0 . 2 1 2 1955 K n i g h t [18] 0 . 4 1 8 - 0 . 7 0 7 - 0 . 4 6 4 0 . 2 1 5 1955 Tanasawa & Kobayasa l [18] 0 . 7 5 - 0 . 5 0 - 0 . 2 5 0 . 2 5 1957 M c l r v l n e [18] 1.28 - 0 . 6 6 - 0 . 3 3 0 . 19 0 . 2 4 1960 Mugele [58] 0 . 6 5 - 0 . 5 5 - 0 . 3 5 0 . 15 0 . 2 0 1961 N e l s o n & S t e v e n s [32] 0 . 4 7 0 . 4 7 - 0 . 8 2 - 0 . 6 4 - 0 . 5 3 - 0 . 5 3 0 . 2 4 0 . 4 2 0 . 2 9 0 . 11 - O r g a n i c l i q u i d s -Water 1964 I l ' y a s h e n k o ft T a l a n t o v [18] 1 .OO - 0 . 8 1 7 0 . 7 7 1967 L a p p e l . Henry & B l a k e [18] 0 . 5 5 - 0 . 7 0 - 0 . 4 5 0 . 20 0 . 2 5 Dependence b a s e d on v a l u e s r e p o r t e d In the l i t e r a t u r e p r i o r to 1967. 1968 Kim & Saunders [33] 0 . 7 3 - 0 . 5 1 1972 Dombrowski ft Wol fshon [38] 0 . 6 7 - 0 . 6 7 1972 Wang ft T i e n [34] 0 . 4 4 - 0 . 8 6 - 0 . 5 5 0 . 2 4 0 . 3 1 - 113 -Figure II-3: Comparison of Drop Size Correlations. IO1 7 5 10° I 7 5 1 Tate & Marshall 2 Mugele 3 Nelson & Stevens 4 Laople 5 Dom5rowskl & Wolfshon 6 Bennington 3 L IO"' 7 5 •-6 10 -2 j i i_ io- 5 7 IO4 REYNOLDS NUMBER (Re) 5 7 10-Spraying Systems Company 1/4LNN2 nozzle atomizing water into air at room temperature. Correlations used are given in text. - 114 -Examination of figure II-3 shows that the absolute drop size predicted by the various correlations varies over a wide range, almost by a factor of ten at any given Reynolds number. However, the dependence of the mean drop size on flow velocity is similar as i s indicated by the similar slopes of the two correlations. Only one orifice diameter was used to prepare this figure. Thus, although the graph as presented is dimensionless, scale up on the basis of orifice diameter should not be attempted. 7. Atomization by Liquid Flashing When a liquid at high temperature suddenly moves into a zone of reduced pressure i t becomes superheated. The liquid must partially vaporize (flash) to attain equilibrium with its surroundings, by removing sensible heat from the liquid through the latent heat of vaporization. Vaporization continues until the remaining liquid i s cooled to the saturation temperature. This generation of vapor can occur at any suitable nucleus in the liquid. Once a bubble is formed, the bubble provides a site where further vaporization can easily occur, promoting rapid bubble growth. This may create a major instability in the liquid. The rapid growth of bubbles caused by flashing may be sufficient to shatter a liquid jet to the extent that i t is atomized. Atomization produced by this means may not require other sources of instabilities as are commonly introduced in spraying nozzles, eg. the tangential swirl - 115 -induced by a grooved core nozzle. Brown and York [21] showed this -that flashing alone, caused by superheating a liquid jet issuing form an or i f i c e , is sufficient to produce sprays having a drop size distribution similar to that produced by other techniques. However, they found that complete jet breakup occurred only when the water temperature was typically 40°C or more above i t s saturation point. In addition they found that the temperature below which no effect was shown on the liquid jet and above which the jet was shattered was only 3°C, with the actual jet shattering temperature determined by the liquid flow rate through the or i f i c e . They correlated their data with water temperature and Weber number as follows: j f . s 1840 - 5.18 T(°F) , T T _.N d 1 Q(microns) = ^ ^ — ( 1 1 - 2 2 ) Brown and York also commented that more rapid disintegration of the liquid mass would be expected for water than for organic fluids due to the much larger rate of bubble growth in water. Also, they suggested that flashing may occur with smaller superheat in larger nozzles. Lienhard [40] examined superheated water jets issuing from 1/8" ID glass tubes. His observations showed that superheats of only 2.5°C could disrupt a turbulent liquid jet and that as the amount of superheat was Increased the divergence of the issuing jet increased. Gooderum and Bushnell [42] studied the mean drop size produced from the atomization of superheated water jets. They found that when - 116 -liquid temperature was above that required to shatter the liquid jet that the drop size was only a function of liquid temperature and nozzle diameters. 8. Summary and Conclusions Although there have been many theoretical and experimental studies of a l l aspects of the atomization process, prediction of spray drop size is s t i l l best made from correlations of experimental results. Some major considerations to take into account when using these correlations are given below: 1. The correlations available in the literature should be used cautiously. Ideally they should be used for the particular nozzle or nozzles for which they were developed, and then only over the range of conditions for which the correlation is valid. Under favorable conditions the mean drops could probably be estimated to within 15 to 25 percent. For the more general correlations, such as the one suggested by Lappel et. a l . (See equation 11-13), prediction to within ±50% would be considered good. 2. The relationship between the mean dropsize and the fundamental spray properties as determined by various investigators can vary widely as shown In Table II-2. While the magnitude of the dependence differs from investigator to investigator, a trend is clearly evident: jet velocity has - 117 -the largest influence on the spray drop size, while the fluid properties of viscosity and surface tension have smaller influences. It has been observed that factors that hinder atomization -low discharge velocity and high liquid viscosity - increase spray nonuniformity. The calculation of mean diameters from the spray distribution should be carried out cautiously. Large errors can result i f the actual drop size distribution does not closely follow the one chosen to represent the distribution. Estimation of mean drop size is best made from the original data using equation II-4. The extrapolation of drop size correlations to conditions beyond which they were developed should be done with extreme caution. For the particular case of the orifice diameter, most studies were made with small scale nozzles having orifice diameters less than four millimeters. While the influence of orifice diameter on spray drop size is anticipated to be similar for larger nozzles, there is no experimental confirmation of this in the literature. It has been noted that when existing correlations are extended beyond their applicable range for orifice diameter that the mean drop size is overestimated. It is possible to completely atomize a fluid jet using liquid superheat alone, but the amount of superheat required - 118 -to achieve t h i s i s generally large. The drop size d i s t r i b u t i o n s produced by t h i s method are comparable to those produced using conventional h y d r a u l i c nozzles. The e f f e c t of atomizing superheated l i q u i d s i n other nozzles, where a spray forming mechanism i s already present, i s not known. - 119 -APPENDIX III REVIEW OF THE PHYSICAL PROPERTIES OF BLACK LIQUOR 1. Introduction Black liquor is the spent cooking liquid after the kraft pulping process. It is an aqueous solution containing material dissolved from the wood and inorganic chemicals. Black liquor composition depends on the mixture of wood species pulped and the operating conditions of the cook. However, a l l black liquors share certain general characteristics in their physical and chemical properties. 2. Chemical Composition The organic components of black liquor are primarily lignin compounds (largely aromatic in nature), carbohydrates, fatty acids and resins. Most of the lignin is solubilized as large colloidal macromolecules with molecular weights ranging from 500 to 1800. The organic fraction exists largely as sodium salts, while the inorganic part of the liquor contains Na2C0 3, Na2S0i t, Na2S, Na2S203, NaOH and NaCl. Depending on the degree of closure of the recovery system, quantities of other chemicals can also build up to significant levels. A description of the f u l l range of the components present in black liquor may be found in standard pulp and paper handbooks [47, 59]. The following is a brief description of the physical properties of black liquor that are important to its spraying. - 120 -3. Liquor Solids Content The solids content is defined as the total dissolved and suspended solids remaining after the evaporation of water from the liquor sample. In practice, because other non aqueous volatile materials are also removed during the evaporation, the solids content is affected by the analytical procedure used. Accordingly the Industry definition is defined by a standard test (TAPPI T 650 su [60]). In essence, this is a gravimetric determination of the solids remaining after a sample of black liquor is evaporated to dryness under controlled conditions.* Because the TAPPI test is rather lengthy, other analytical techniques that correlate with the TAPPI test have been developed. Nevertheless, values of liquor solids content in the literature are usually reported as TAPPI solids. There are a number of analytical techniques used to measure black liquor solids content. These include evaporation (various oven drying and microwave drying procedures), d i s t i l l a t i o n , and chemical methods. It Is not possible to compare the absolute accuracy of each technique because there is no way to determine exactly how much water is present as H2O in the liquor. Wagoner and Veeci [61] compared several techniques used for liquor solids determination and found as much as *Black liquor samples are dried at 105°C for a minimum of 6 hours with an inert surface extender and a controlled flow of dried air to increase drying rate and eliminate moisture entrapment. Strong black liquors are diluted to allow volumetric handling and to reduce scum formation. - 121 -five percent difference in reported solids content between them. These differences were attributed to the different temperature maxima reached by the liquor sample during testing. Tests that reached higher liquor temperatures resulted in lower reported solids content. Wagoner and Veeci identified the potential problems affecting the solids content determination as: 1. formation of a surface film, 2. loss or retention of water of hydration from organic salts, 3. loss or retention of volatile matter, 4. oxidation of liquor constituents, 5. water produced by reaction of NaOH with organic liquor constuents, 6. water produced by degradation of organic liquor constituents, and 7. detection of other liquor constituents and water of hydration as free water. In our study, we determined black, liquor solids content using the f i l t e r paper procedure developed by McDonald [62]. This procedure requires less time to complete than the TAPPI standard procedure and correlates well with i t . This correlation is given below: TAPPI (% solids) = 1.018 x F i l t e r Paper (% solids) -0.4 (III-l) A l l solids contents reported in this thesis are TAPPI solids. - 122 -4. Boiling Point Rise The boiling point rise of a black liquor is the difference between the boiling point of the liquor and that of pure water at a given pressure. Its value is primarily effected by the liquor solids content, and to a lesser extent by liquor composition, in particular the ratio of organic to inorganic material in the liquor. Clay and Grace [15] have summarized the investigations made of the the boiling point rise of kraft black liquor. These findings are shown in figure I I I - l . Most investigations place the boiling point rise of a kraft black liquor with 65% solids content between 12-15°C. 5. Liquor Density The density of black liquor is influenced primarily by its solids content and to a lesser degree by liquor temperature and composition. The density of various black liquors have been reported by a number of investigators including Hultin [63], Koorse and Veeramani [64], and Laurola and Wallendahl [65]. A correlation for liquor specific gravity as a function of solids content and liquor temperature was given by Jagannath [66]. Most investigators report liquor densities of approximately 1.35 g/cm for liquor with 65% solids content. 6. Surface Tension There have been few investigations of black liquor surface - 123 -Figure I I I - l : Kraft Liquor Boiling Point Rise Data from Several Sources. 35 h Andrews. 1982 Clay, 1981 Andrews. 1981 Grace, 1981 Frederick, 1980 Arhippainen, 1968 Han, 1957 Kobe, 1939 yy D5] _L 35 45 55 65 75 85 Solids Content (wgt % O.D.) 95 - 124 -tension, and only one where a value is reported for a liquor having a solids content greater than 50%. Surface tension measurements are d i f f i c u l t to obtain for concentrated liquors due to the tendency of the liquor to form a surface film. One of the earliest measurements of surface tension was made by Maksimov et. a l . [67]. They correlated the surface tension of white and black liquor with alkali content and temperature. This correlation was used to predict liquor surface tension in Merriam's computer model of a recovery furnace [10]. Mehrotra and Veeramani [68] measured the surface tension of bamboo and bagasse black liquors at low solids content using the capillary rise method. Beckwith et. a l . [69] used a Du Nouy ring tensiometer for surface tension measurements of softwood black liquors up to 45% solids content. Surface tensions for liquors of greater solids contents could not be determined because a tube of liquor was pulled from the surface. So'derhjelm and Koivuniem [16] obtained a value of approximately 34 dynes/cm for a 61% solids content liquor using a method that involved droplet formation at a capillary. They commented that this determination was likely inaccurate due to high liquor viscosity and poor drop formation. The consensus among the reviewed articles is that surface tension decreases with increasing temperature. From So'derhjelm and Koivuniem's work i t appears that as liquor solid content is increased surface tension f i r s t decreases, reaches a plateau and then increases again. The reviewed literature is summarized in table I I I - l . Most researchers report typical values of black liquor surface tension of 30-40 dynes/cm. TABLE I I I - l SUMMARY OF LITERATURE WORK ON BLACK LIQUOR SURFACE TENSION Year I n v e s t l g a t o r ( s ) and R e f e r e n c e Method Used L I q u o r T e s t e d Comments 1966 Makslroov, Bushmelev . V o l ' f & I s a e v a (67) ( R u s s . ) not g i v e n k r a f t w h i t e ft b l ack I n s t i t u t e of Paper Chemlstery A b s t r a c t . E q u a t i o n g i v e n to c o r r e l a t e s u r f a c e t e n s i o n w i t h a l k a l i c o n t e n t , C (g/1) and tempera tu re , t (*C): a • 7 6 . 2 + O.O805C - 0 . 1 6 7 t S u r f a c e t e n s i o n i s a f f e c t e d by c o m p o s i t i o n , w i t h o r g a n i c components r e d u c i n g a and i n o r g a n i c components i n c r e a s i n g o 1966 V o l k o v . Kh im. P e r e r a b o t k a D r e v e s l n y . R e f . I n f o r m , n o . 4 : 8 - 9 ( 1 9 6 6 ) . [ R u s s . ] ; R e f . Z h . . Kh im. no 13:AS335 ( J u l y 10. 1966) . not g i v e n k r a f t I n s t i t u t e o f P a p e r Chemlstery A b s t r a c t . S u r f a c e t e n s i o n i n c r e a s e d w i t h s o l i d s c o n t e n t but not e f f e c t e d by s u l f a t e soap c o n c e n t r a t i o n . 1968 H u l t i n [63] T e n s i o -meter S u l f i t e S u l f i t e l i q u o r was t e s t e d from 11 to 57 p e r c e n t s o l i d s and f rom 20 t o 9 0 " C . V a l u e s f o r a ranged from 50 t o 37 dynes/cm. 1970 V o l k o v & G r t g o r ' e v . L e s n a y a P r o m y s h l e n n o s t ' , Moscow, ( 1 9 7 0 ) . [ R u s s ] not g i v e n k r a f t ft s u l f 1 t e I n s t i t u t e of Paper Chemls tery A b s t r a c t . O ther p h y s i c a l p r o p e r t i e s o f spent l i q u o r s a r e g i v e n as w e l l . 1970 P o l y a k o v & Marshak , T r . L e n i n g r a d . T e k h n o l . I n s t . T s e l l y u l . - B u m a z h . Prom. n o . 2 7 : 2 1 - 7 ( 1 9 7 0 ) . [ R u s s . ] not g i v e n soda & k r a f t I n s t i t u t e of Paper Cheroistery A b s t r a c t . N o t e d g r a d u a l d e c r e a s e of s u r f a c e t e n s i o n as o r g a n i c c o n t e n t I n c r e a s e d . 1976 F o l l a d o v a & K l p r l a n o v , I z v . MUZ. L e s n o i Zh . 19. n o . 5 : 9 1 - 9 3 ( 1 9 7 6 ) . [ R u s s . ] not g i v e n hardwood k r a f t I n s t i t u t e o f Paper Chemls tery A b s t r a c t . S u r f a c e t e n s i o n of hardwood l i q u o r d e c r e a s e d l i n e a r l y w i t h i n c r e a s i n g t e m p e r a t u r e . 1977 M e h r o t r a ft Veeramant [68] C a p ! 1 l a r y r 1 se Bamboo, B a g a s s e ft mixed k r a f t S u r f a c e t e n s i o n s measured at low l i q u o r s o l i d s c o n t e n t . 10-3554. and f rom 2 7 - 9 5 " C . The s u r f a c e t e n s i o n r a n g e d from 15 t o 45 dynes/cm. 1981 B e c k w l t h , Smal l & Wood [69] Ou Nouy r i n g tens IO-meter k r a f t S u r f a c e t e n s i o n measured f o r southern k r a f t l i q u o r s gave v a l u e s of s u r f a c e t e n s i o n of 31 -35 dynes/cm up t o 4554 s o l i d s . 1982 S o d e r h j e l m & K o t v u n l e m i [16] C a p l 1 l a r y d rop method k r a f t V a l u e s of s u r f a c e t e n s i o n a re g i v e n f o r v a r i o u s s o l i d s c o n t e n t up to 6154 s o l i d s . The authors commented on the p r o b a b l e I n a c c u r a c y of v a l u e s o b t a i n e d at the h i g h e r s o l i d s c o n t e n t due to h i g h l i q u o r v i s c o s i t y and poor d r o p f o r m a t i o n . The d a t a show an i n i t i a l d e c r e a s e In a as l i q u o r s o l Ids a r e Increased and p o s t u l a t e d an i n c r e a s e tn a a f t e r a p p r o x i m a t e l y 4054 s o l i d s . - 126 -7.0 Viscosity The viscosity of black liquor has been measured in a number of investigations. The aim of the review is restricted to data and means of predicting the viscosity of black liquor at high temperatures and high solids content. The f i r s t study of black liquor viscosity was made in 1949 by Kobe and McCormarck [70]. They studied three different pulping liquors: soda, sulfite and sulfate over a range of 14-48% liquor solids content and up to 97°C using Ostwald viscometry. They developed a nomograph for spent liquors based on a l l data and made no distinction between liquor types. Hedlund [71] reported viscosities for sulfate liquors with different inorganic contents at the same solids level. Han [72] was the f i r s t to report a non-Newtonian behaviour for neutral sulfite spent liquor - a thixotropic behaviour at high solids content. In 1977, Oye et. a l . [73] reported the viscosity of black liquors from various tropical woods. Although liquor analyses were made, no attempt was made to correlate these with liquor viscosity. Stenuf and Agrawal [74] measured the viscosity of several black liquors with three different types of viscometers. The viscosities they measured using an Ostwald viscometer and a flow tube viscometer of their own design were markedly different than those determined using a rotational viscometer. They dismissed the results of the rotational viscometer, but gave no sound reason for this decision. Kim et. a l . [29] studied kraft softwood liquors at high solids contents of 54-69%, up to 90°C, using a wide - 127 -range of shear rates. They concluded that the liquors exhibited shear thinning and found the departure from Newtonian behaviour marked at lower temperatures and higher solids contents. They also noted that both liquor viscosity and shear rate behaviour varied significantly with liquor source. The general findings of this literature search is summarized in Table III-2. Figure III-2 compares the available viscosity data found for black liquors having solids contents ranging from 65 to 67%. Here, viscosity is plotted against liquor temperature. Figure III-2 shows that reported liquor viscosities vary by almost two orders of magnitude at conditions typical of liquor f i r i n g in a recovery furnace (65% solids and 110-115°C). In view of this wide variation and no obvious way of reconciling i t , we decided that i t was necessary to measure the viscosity of any specific liquor used in our atomization tests. 8. Characterization of Black Liquor Used i n this Study The liquor chosen for study was from a typical coastal kraft m i l l i n British Columbia pulping a wood mixture of Hemlock and Balsam f i r . The liquor was obtained from the oxidized strong black liquor storage tank and diluted to maintain i t s homogeneity during transportation and storage. Prior to the spray tests the liquor was concentrated to the desired solids content by evaporation over a hot plate. A nitrogen purge was kept over the liquor surface during evaporation to minimize oxidation. TABLE I U - 2 SUMMARY OF LITERATURE WORK ON BLACK LIQUOR VISCOSITY Year I n v e s t I g a t o r ( s ) and Refe rence V i s c o m e t e r Used L1quor Tested So l Ids Range X Temp. Range •C D a t a G i v e n Comments 1949 Kobe & McCormack [70] O s t w a l d S u l f a t e 14-48 0 - 9 7 yes Nomograph f o r s o d a , s u l f a t e & s u l f i t e l i q u o r . No d i s t i n c t i o n between l i q u o r t y p e s . 195 t Hedlund [71] Hopp1er S u l f a t e 0 - 6 5 2 0 - 2 0 0 yes 1954 Kennedy [11] not g i v e n S u l f a t e 5 5 - 6 8 10-148 no 1955 D a v i s [75] not g i v e n not g i v e n 4 5 - 7 0 6 - 2 0 4 no Nomograph, no d a t a o r I n f o r m a t i o n g i v e n 1955 H a r v l n (76) Os twa ld S u l f a t e 13 -53 3 8 - 9 3 y e s Used Cannon -Fenske -Os twa ld type v i s c o m e t e r 1957 Han [72] B r o o k f i e l d & Os twa ld S u l f i t e 10-47 2 5 - 1 0 0 y e s Non-Newtonian 1967 Re lche (13] Hopp le r & E n g l e r S u l f a t e 0 - 6 0 3 0 - 1 1 0 no 1968 H u l t l n [63] Hopp1er S u l f a t e 0 - 6 5 2 0 - 1 5 0 no E x t r a p o l a t i o n above 100'C 1968 Lengyel [77] not g i v e n Straw S u l f a t e 1 0 - 5 0 2 0 - 1 4 0 no 1969 Lankenau & F l o r e s [78] not g i v e n S u l f a t e 6 0 - 6 7 5 0 - 1 7 5 no Graphs f o r v a r i o u s l i q u o r s 1977 Oye et a l . [73] Epprecht Hardwood E u c a l p t S u l f a t e 9 - 7 0 2 0 - 6 0 yes Fo r l i q u o r s s t u d i e d , v i s c o s i t y i n c r e a s e d w i th i n c r e a s i n g o r g a n i c mat ter 1980 Jagannath [30] not g i v e n S u l f a t e <40 >40 no Two c o r r e l a t i o n s a r e g i v e n . No d a t a or l i m i t s a r e g i v e n f o r the e q u a t i o n s . 1980 Moser [79] Haake SV S u l f a t e 5 1 - 6 7 12 -69 yes D i f f i c u l t y w i th skimming 1980 Stenuf & Agrawal [74] Flow tube , Ostwald & B r o o k f i e l d Softwood Hardwood S u l f a t e 15-65 12 -69 yes Compared v a r i o u s types of v i s c o m e t e r s . They n o t e d l a r g e d i f f e r e n c e s w i t h v i s c o s i t i e s d e t e r m i n e d w i th the B r o o k f i e l d v i s c o m e t e r . 1981 K a r o l y [80] no t g i ven S u l f a t e 6 7 - 7 7 5 8 - 9 0 yes V a r i e d shear r a t e . Non-Newtonian 198 1 K i n , Co & F r i c k e [29] C a p l 1 l a r y Softwood S u l f a t e 5 4 - 6 9 3 0 - 9 0 yes V a r i e d shear r a t e from 10 to 5000s ' 1981 Sandquls t [28] C o n t r a v e s Rheomat 15 S u l f a t e 6 3 - 7 3 I10&115 yes V a r i e d shear r a t e . Non-Newtonian 1982 K o r p l o & V l r k o l a [81] not g i v e n S u l f a t e 55 90 yes Data as p a r t of s tudy of b l a c k l i q u o r s 1982 Llera [82] Flow tube S u l f a t e 4 4 - 6 7 8 9 - 1 0 5 yes P o i s e l l e f low . non-Newtonian 1982 Sadawarte e t . a l . [83] C a p i 1 l a r y S u l f a t e 10-60 90 yes Bagasse & bamboo 1 iquors Figure HI-2: Temperature Dependence of 65% Solids Content Black Liquors. I0« IO 5 IO 4 o >- io3 co O o > IO 2 10' \ \ 1^0 1 H e d l u n d 2 Kennedy 3 D a v i s 4 R e i c h e 5 H u l t i n 6 Lankenau & F l o r e s 7 J a g a n n a t h 8 Moser ( 65.2% ) 9 S t e n u f & Agrawal 10 Kim, Co s F r i c k e (66.1 11 S a n d q u l s t ( 66.7% ) 12 Liem ( 66.5% ) 13 B e n n i n g t o n 10° 4 0 6 0 8 0 100 120 140 TEMPERATURE (°C) 160 180 2 0 0 - 130 -The fol lowing figures and tables characterize the l iquor chemical composition, density as a function of so l ids content, and v i s c o s i t y as a function of both temperature and so l ids content. The l iquor surface tension and b o i l i n g point r i s e were not measured, but were estimated using information avai lable i n the l i t e r a t u r e as discussed i n the previous sect ions . Chemical Composition; Results of a chemical analysis made on the l iquor i s sumarized i n table I I I - 3 . For de ta i l s regarding the tes t ing procedures the reader should consult the TAPPI standard procedures [60]. The high NaCl content reported i n table I I I -3 i s t y p i c a l for coas ta l m i l l s pulping ocean-borne logs . Black Liquor Density: To estimate the black l iquor density at any given so l ids content, a co r r e l a t i on was developed based on information supplied by the m i l l [84]. 167 i n d i v i d u a l density measurements spanning a range of so l ids content from 10 to 67% were used i n developing th is c o r r e l a t i o n , given below: p(g/aa 3) - 0.950 + 6.503 x 10~ 3 (% s o l i d s ) Figure I I I -3 shows the agreement between this equation and the data. Because the data and equation are for l i quor at 90°C, density correc-tions for temperature were estimated based on H u l t i n ' s resu l t s [63]. - 131 -Table III-3 Chemical Analysis of West Coast Black Liquor Tested. Dilution factor 1.419 Total solids - diluted black liquor 35.6% w/w Total solids - original black liquor 50.5% w/w Chemical Analysis* % w/w ODS** "NaOH" 5.03 Na2S 0.21 Na2C03 8.55 Na2S203 4.90 Na2S0it 1.04 NaCl 15.2 Total Na 20.9 Total S 3.23 TOC 31.4 Ash 50.7 Calorific Value 5189 BTU/lb ODS Density 1.212 g/ml *for testing procedure see TAPPI TIS sheets [60]. **0DS = Oven dried solids. - 133 -Liquor Viscosity: The liquor viscosity is the most important liquor variable in atomization. Consequently much detail has been given about this subject (see sections 3.5, 4.1 and III-7). The correlation developed for this liquor (equation (4)) is used in figure III-4 to predict the liquor viscosity between 35 and 70% solids content from 20 to 130°C. - 134 -Figure III-4: West Coast Black Liquor Viscosity. 10,000 'lO 20 30 40 50 60 70 80 90 IQO 110 120 130 140 TEMPERATURE (°C) - 135 -APPENDIX IV: COMPUTER PROGRAM FOR SPRAT DROP SIZE DISTRIBUTION ANALYSIS 1 2 C C DROP SIZE DISTRIBUTION ANALYSIS ROUTINE 3 4 C C This program takes the Information from a drop s i ze d i s t r i b u t i o n 5 ' C presented as the number of d i sc rete occurences 1n classes of 6 7 C Q known s i ze , and computes the fo l lowing propert ies of the d i s t r i b u t i o n : 8 c (1) Linear Mean Diameter 9 c (2) Surface Mean Diameter 10 c ' (3) Volume Mean Diameter 1 1 c (4) Sauter Mean Diameter 12 c (5) Geometric Mean Diameter 13 c (6) Square.Root Mean Diameter 14 c (7) Normal Standard Dv1at1on 15 c (8) Log Normal Standard Deviation, and 16 c (9) Square-Root Normal Deviat ion. 17 c -18 c The data deck for th i s program may be set up 1n two ways. The s ize of 19 c each c lass may be ca lcu la ted from appropriate Information, or read in 20 c from a f i l e . (The l a t te r w i l l allow the use of non-un1formly s ized 21 c i n terva l s ) 22 c 23 c 24 c (A) Ca lculated Class Increments 25 c 26 c The card deck (1n Input unit 5) must be structured as fol lows: 27 c (The appropriate format Is given in braces) 28 c 29 c (1) N, The number of c lasses, (12) 30 c (2) The number ' 1 ' , Indicating that the Information for the 31 c c lass s izes 1s to be ca lcu la ted, (11) 32 c (3) The s t a r t ing pos i t ion of the f i r s t increment, (F5.1) 33 c (4) The Incremental step for each c la s s , (F5.1) 34 c (5) Five cards g iv ing Information about the spray from 35 c which the d i s t r i b u t i o n was produced, including the: 36 c - Data set ID number 37 c - F l u i d atomized 38 c - Nozzle used 39 c - Atomizer pressure 40 c - L iqu id temperature 41 c (6) The number of drops In each class.. There must be N 42 c data sets. 43 c 44 c 45 c (B) Class Sizes Read in from F i l e s 46 c 47 c The card deck is in Input unit 5, structured as before, with the 48 c fo11ow1ng except 1ons: 49 c 50 c (1) Card 2 is ' 0 ' , 51 c (2) Cards 3 & 4 are el iminated. 52 c 53 c The c lass s izes are read from input unit 7, structured in the fol lowing 54 c way: 55 c 56 c FROM TO MEAN 57 c 58 c The format 1s (3F7.3). There must be N ent r ie s . 59 c 60 c cpjb - 136 -61 62 63 IMPLICIT REALM (A-H, 0-Z) 64 DIMENSION M(150). L ( 1 5 0 ) . SCALE(150,3). DR0P(150,5) 65 REALM MEAN, SURF, VOLUME, SAUTER, CHECK 66 REALM LOWER, DINCR, STDEV 67 REALM GEO, LSD 68 REALM SRN, SRDEV 69 INTEGER COUNT, N, INPUT 70 INTEGER CHAR(5.80) 71 72 DATA COUNT, MEAN, SURF / 0, 0.0, 0.0 / 73 DATA VOLUME, SAUTER, CHECK / 0.0, 0.0, 0.0 / 74 DATA STDEV / 0.0 / 75 DATA GEO, LSD / 0.0, 0.0 / 76 DATA SRN. SRDEV / 0.0, 0.0 / 77 78 READ(5,4) N 79 4 FORMAT(12) 80 READ(5,5) INPUT 81 5 FORMAT(11) 82 83 C Input o f C l a s s S i z e s 84 85 IF (INPUT.E0.1) GO TO 20 86 DO 15 IR0W=1,N 87 READ(7,10) (SCALE(IROW,ICOL), IC0L=1,3,1) 88 10 FORMAT (3F7.3) 89 15 CONTINUE 90 GO TO 40 91 20 CONTINUE 92 READ(5,21) LOWER 93 READ(5,21) DINCR 94 21 FORMAT (F5. 1 ) 95 SCALE(1,1)=LOWER 96 SCALE(1,2)=L0WER+DINCR 97 SCALE( 1 ,3) = (L0WER+SCALE(1,2))/2 98 DO 25 IR0W=2,N 99 SCALE(IROW,1)=SCALE(IROW-1,1)+DINCR 100 SCALE(IR0W,2)=SCALE(IR0W-1,2)+DINCR 101 SCALE(IROW,3)=SCALE(IR0W-1,3)+0INCR 102 25 CONTINUE 103 40 CONTINUE 104 105 C Reading of Spray Data I n f o r m a t i o n 106 107 DO 50 1=1,5 108 READ (5.45) (CHAR(I.J). 0=1,80,1) 109 45 FORMAT (80A1) 110 50 CONTINUE 1 11 112 C Input of 0r o p - s 1 z e D i s t r i b u t i o n 113 114 DO 70 IR0W=1,N 115 M(IROW)=IROW 116 READ(5.60) L(IROW) 117 60 FORMAT (14) 118 COUNT=COUNT+L(IROW) 119 70 CONTINUE 120 - 137 -121 C 122 123 124 125 126 127 128 100 129 130 131 132 120 133 134 135 136 137 138 139 140 141 140 142 150 143 144 145 146 147 148 149 150 C C 151 152 153 154 155 156 157 190 158 200 159 160 161 162 163 164 C 0 165 166 167 225 168 169 240 170 171 245 172 173 247 174 175 250 176 177 260 178 179 270 180 C a l c u l a t i o n of Mean Diameters DO 100 IROW-1,N DROP(IROW,1)=FLOAT(L(IROW))/FLOAT(COUNT) DR0P(IROW.2)-DROP(IROW,1)*SCALE(IROW,3) DROP(IROW.3)-DROP(IROW,1)"SCALE(I ROW,3)**2 DR0P(IR0W,4)=DR0P(IR0W,1)*SCALE(IR0W,3)**3 CONTINUE DROP(1,5)=DR0P( 1,1) DO 120 IR0W=2,N DROP(IROW.5)-DROP(IROW-1,5)+DROP(IROW,1) CONTINUE DO 150 IR0W=1,N CHECK=CHECK+DROP(IROW,1) MEAN=MEAN+DR0P(IROW,2) SURF=SURF+OROP(IR0W.3) VOLUME=VOLUME+DROP(IR0W.4) IF (L(IROW).EO.O) GO TO 140 GEO=GEO+DROP(IROW,1)*ALOG(SCALE(IROW,3)) SRN=SRN+L(IR0W)*S0RT(SCALE(IR0W,3)) CONTINUE CONTINUE SAUTER-VOLUME/SURF SURF=SORT(SURF) VOLUME=(ALOG(VOLUME))/3 VOLUME-EXP(VOLUME) GEO=EXP(GEO) SRN=(SRN/COUNT) C a l c u l a t i o n o f St a n d a r d D e v i a t i o n s DO 200 IR0W=1,N IF (L(IROW).EO.O) GO TO 190 STDEV = STDEV+L(IROW)*(SCALE(IROW.3)-MEAN)* *2 LSD=LSD+L(IR0W)*((AL0G(SCALE(IR0W,3))-ALOG(GEO))**2) SRDEV=SRDEv+L(IR0W)*(SQRT(SCALE(IR0W,3))-SQRT(SRN)**2)**2 CONTINUE CONTINUE STDEV=SQRT(STDEV/(C0UNT-1)) LSD=SQRT(LSD/COUNT) LSD=EXP(LSD) SRDEV-(SRDEV/COUNT) Output of Data WRITE (6,225) FORMAT ( ' 1 ' ,/) WRITE (6,240) FORMAT (' SPRAYABILITY OF CONCENTRATED ') WRITE (6,245) FORMAT ( ' BLACK LIQUOR - MASc THESIS') WRITE (6,247) FORMAT (' ',/) WRITE (6,250) (CHAR(1,J), J-1,80,1) FORMAT (' ' . ' I d e n t i f i c a t i o n Number: ',80A1) WRITE (6,260) (CHAR(2,J), J=1,80,1) FORMAT (' ' , ' F l u i d Atomized: '.80A1) WRITE (6.270) (CHAR(3,J), J-1.80.1) FORMAT (' ','Nozzle Used: '.80A1) WRITE (6.280) (CHAR(4,J). J-1,80,1) - 138 -181 280 FORMAT (' ','Atomizer P r e s s u r e : ',80A1) 182 WRITE (6,290) (CHAR(5,J), 0=1,80,1) 183 290 FORMAT (' ','Temperature: '.80A1) 184 WRITE (6,295) COUNT 185 295 FORMAT (' '.'Drops Counted: ',14) 186 WRITE (6,247) 187 WRITE (6,300) 188 300 FORMAT ( ' CLASS FROM TO MEAN COUNTS REL, 189 1 FRACTION CUMULATIVE' ) 190 DO 400 IR0W=1,N 191 400 WRITE (6,410) M(IROW), (SCALE(IROW,d), J=1,3,1), 192 1 L(IROW), DROP(IROW,1), DR0P(IR0W,5) 193 WRITE (6,247) 194 410 FORMAT (3X,12,5X,F6.2,2X.F6 . 2,3X,F6.2,5X,14,10X,F6.4,12X,F6.4 195 WRITE (6,247) 196 WRITE (6,420) COUNT, CHECK 197 420 FORMAT ( ' Sum= ',14, 198 1 ' '.F6.4) 199 WRITE (6,247) 200 WRITE (6,225) 201 WRITE (6.240) 202 WRITE (6,245) 203 WRITE (6,247) 204 WRITE (6.250) (CHARM.J). J-1,80.1) 205 WRITE (6.247) 206 WRITE (6.247) 207 WRITE (6,440) 208 440 FORMAT ( ' CALCULATED DROPSIZE DIAMETERS FROM DISTRIBUTION') 209 WRITE (6,247) 210 WRITE (6,450) MEAN 211 450 FORMAT (' L i n e a r Mean: ',F8.3) 212 WRITE (6.460) SURF 213 460 FORMAT (' S u r f a c e Mean: '.F8.3) 214 WRITE (6,470) VOLUME 215 470 FORMAT (' Volume Mean: '.F8.3) 216 WRITE (6,480) SAUTER 217 480 FORMAT (' Sauter Mean: ',F8.3) 218 WRITE (6,490) GEO 219 490 FORMAT (' Geometric Mean: '.F8.3) 220 WRITE (6,495) SRN 221 495 FORMAT (' Square Root Mean:',F8.3) 222 WRITE (6,247) 223 WRITE (6,500) 224 500 FORMAT ('CALCULATED STANDARD DEVIATIONS ') 225 WRITE (6,247) 226 WRITE (6,550) STDEV 227 550 FORMAT (' Normal Standard D e v i a t i o n : '.F8.3) 228 WRITE (6,600) LSD 229 600 FORMAT (' Log Normal Standard D e v i a t i o n : '.F8.3) 230 WRITE (6.650) SRDEV 231 650 FORMAT (' Squ a r e - r o o t Normal Standard O e v i a t i o n : ' , F 8 . 3 ) 232 WRITE (6,70O) 233 700 FORMAT (' ',/////) 234 STOP 235 END End of f i l e - 139 -SPRAYABILITY OF CONCENTRATED BLACK LIQUOR - MASc THESIS I d e n t i f i c a t i o n Number: F l u i d Atomized: N o z z l e Used: A t o m i z e r P r e s s u r e : Temperature: Drops Counted: RUN 73 64.8% G l y c e r o l / W a t e r 1/4LNN2 195 p s i g 23 C 2516 CLASS 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 16 17 18 19 20 21 22 FROM TO MEAN COUNTS RELATIVE FRACTION 0.0 10.00 5.00 1 0.0004 10.00 20.00 15.00 38 0.0151 20.00 30.00 25.00 573 0.2277 30.OO 40.00 35.00 590 0.2345 40.00 50.00 45.00 353 0.1403 50.00 60.00 55.00 303 0.1204 60.00 70.00 65.00 214 0.0851 70.00 80.00 75.00 159 0.0632 80.00 90.00 85.00 116 0.0461 90.00 100.00 95.00 64 0.0254 100.00 110.00 105.00 43 0.0171 110.OO 120.OO 115.00 28 0.0111 120.00 130.00 125.00 13 0.0052 130.00 140.00 135.00 7 0.0028 140.00 150.00 145.00 7 0.0028 150.00 160.00 155.00 3 0.0012 160.00 170.00 165.00 2 0.0008 170.00 180.00 175.00 1 0.0004 180.00 190.00 185.00 0 0.0 190.00 200.00 195.00 0 0.0 200.00 210.00 205.00 0 0.0 21O.0O 220.00 215.O0 1 0.0004 CUMULATIVE 0.0004 0.0155 0.2432 0.4777 0.6180 0.7385 0.8235 0.8867 0.9328 0.9583 0.9754 0.9865 0.9917 0.9944 0.9972 0.9984 0.9992 0.9996 0.9996 0.9996 0.9996 1.OOOO Sum= 2516 1.OOOO - 140 -SPRAYABILITY OF CONCENTRATED BLACK LIQUOR - MASc THESIS I d e n t i f i c a t i o n Number: RUN 73 CALCULATED OROPSIZE DIAMETERS FROM DISTRIBUTION L i n e a r Mean: 48.641 S u r f a c e Mean: 54.455 Volume Mean: 60.627 Sa u t e r Mean: 75.152 Geometric Mean: 43.494 Square Root Mean: 6.780 CALCULATED STANDARD DEVIATIONS Normal S t a n d a r d D e v i a t i o n : 24.487 Log Normal S t a n d a r d D e v i a t i o n : 1.594 Sq u a r e - r o o t Normal Standard D e v i a t i o n : 2.673 - 141 -APPENDIX V: DATA Figure V-I: Flow Rate Data for 1/4LNN Series Nozzles. 0.05r-0.01 "n 1/4LNN26 J 1/41NN14 1/4LNN8 o 1/4LNN2 1/4LNN.6 • Water, p« 1 cp • 64.&% w/w Glycerol/Water, y= 14.7 cp 0 82.5% w/w Glycerol/Water, p- 68.0 cp A 89.7S w/w Glycerol/Water, u» 205 cp 10 20 50 100 200 OPERATING P R E S S U R E (psig) 500 100' - 142 -Table V-l Tabulation of Experimental Measurements of West Coast Black Liquor Viscosity. Tappi Percent Solids Temperature °C Viscosity cp Comments 68.8 68.8 68.8 68.8 68.8 62.2 62.2 62.2 56.3 56.3 56.3 55.2 55.2 55.2 45.8 45.8 45.8 45.8 38.2 38.2 38.2 76.5 90.5 100.5 107.0 127.0 86.0 101.0 121.5 71.0 91.0 111.0 60.0 81.0 100.0 36.0 57.0 73.5 84.0 26.0 42.0 61.0 5209 1178 1031 290.3 83.0 654.3 150.4 9.8 191.7 85.5 33.6 231.3 81.0 39.0 62.6 26.9 16.7 15.1 15.4 9.4 8.2 Liquor Boiling in c e l l TABLE V - 2 PHYSICAL PROPERTIES OF GLYCEROL/WATER SOLUTIONS AT 2 3 » C DETERMINED FROM REFRACTIVE INDICES ~ " G l y c e r o l Sample I d e n t i f i c a t i o n : R e f r a c t 1ve Index a t 2 0 ° C G l y c e r o l P e r c e n t w / w Dens 1ty P g/cm' S u r f a c e Tens Ion a dynes/cm V 1 s c o s I t y 1 c cp VI s c o s 1 t y ' c c p S t o c k G l y c e r o l (99.5%) 1.4715 9 8 . 6 G l y c e r o l d i l u t i o n #1, b e f o r e t e s t s a f t e r t e s t s a v e r a g e 1 .4579 1.4579 8 9 . 7 8 9 . 7 8 9 . 7 1.2323 1.2323 1 .2323 64 . 3 64 . 3 6 4 . 3 2 2 2 . 9 2 2 2 . 9 2 2 2 . 9 2 0 5 . 0 G l y c e r o l d i l u t i o n #2, b e f o r e t e s t s a f t e r t e s t s a v e r a g e 1.4472 1.4467 8 2 . 6 9 8 2 . 3 6 8 2 . 5 1.2137 1.2128 1 .2132 6 5 . 2 75. 24 7 3 . 15 7 4 . 2 6 8 . 0 G l y c e r o l d i l u t i o n #3, b e f o r e t e s t s a f t e r t e s t s a v e r a g e 1 .4190 1.4212 6 4 . 0 7 6 5 . 5 3 64 .8 1 . 1634 1 . 1673 1.1654 6 7 . 5 13 .70 1 5 . 3 0 14 .5 14 .7 LO I v ] s c o s 1 t 1 e s d e t e r m i n e d a t 2 0 ° C f rom r e f r a c t i v e Index measurements V i s c o s i t i e s d e t e r m i n e d a t 2 3 ° C u s i n g Haake RV12 R o t o v l s c o - 144-4. Introduction to Spray Analysis Data Tables The following sections give the data for each individual test made in the course of this study. The tabulated spray parameters were determined as described in section 3.4 and require no further comment here. In table V-7 the following abbreviations are used: Poor Atom = the atomization produced by the nozzle was judged to be poor. Some Flash = the presence of a mist in the center region of the spray. % S BL => black liquor solids content TABLE V - 3 SUMMARY OF EXPERIMENTAL RESULTS: P a r t I  A t o m i z a t i o n of Water and G l y c e r o l / W a t e r M i x t u r e s T e s t No. N o z z l e G l y c e r o l Water Weight Percent F l u i d Temp • c Atom. P r e s . p s i g O r i f i c e 0 tameter cm Uo cm/s P O e n s l t y g/cm' a S u r f a c e Tens i o n dynes/cm V i s e , cp Re We Drops Counted Mean D1ameter d i o f,m 1 1/4LNN.6 0 . 0 17 50 0 .0406 547. 1 0 . 9 9 8 9 7 3 . 2 0 1.081 2053 165.8 384 6 9 . 9 2 1/4LNN.6 0 . 0 17 50 0 .0406 547 . 1 0 . 9 9 8 9 7 3 . 2 0 1.081 2053 165.8 1178 5 6 . 7 3 1/4LNN.6 0 . 0 17 100 0 .0406 7 3 3 . 8 0 . 9 9 8 9 7 3 . 2 0 1.081 2753 2 9 8 . 3 1061 6 0 . 0 4 1/4LNN.6 0 . 0 17 100 0 .0406 7 3 3 . 8 0 . 9 9 8 9 7 3 . 2 0 1.081 2753 2 9 8 . 3 3199 47 . 4 5 1/4LNN.6 0 . 0 17 150 0 .0406 8 6 9 . 0 0 . 9 9 8 9 7 3 . 2 0 1.081 3260 4 1 8 . 4 2436 3 9 . 1 6 I/4LNN.6 0 . 0 17 200 0 .0406 9 7 8 . 4 0 . 9 9 8 9 7 3 . 2 0 1.081 3671 5 3 0 . 4 4282 2 8 . 8 7 1/4LNN.6 0 . 0 17 200 0 .0406 9 7 8 . 4 0 . 9 9 8 9 7 3 . 2 0 1.081 3671 5 3 0 . 4 2017 22 .6 a 1/4LNN.6 0 . 0 17 300 0 .0406 1 159 0 . 9 9 8 9 7 3 . 2 0 1.081 4348 7 4 4 . 2 3536 1 9 . 5 9 1/4LNN.6 0 . 0 18 400 0 .0406 1300 0 . 9 9 8 6 7 3 . 0 4 1.053 5005 9 3 8 . 4 1588 1 3 . 9 10 1/4LNN.6 0 . 0 18 400 0 .0406 1300 0 . 9 9 8 6 7 3 . 0 4 1.053 5005 938. 1 2869 17 . 7 1 1 1/4LNN.6 0 . 0 18 550 0 .0406 1493 0 . 9 9 8 6 7 3 . 0 4 1 .053 5748 1237 243 1 5 . 5 12 1/4LNN.6 0 . 0 18 550 0 .0406 1493 0 . 9 9 8 6 7 3 . 0 4 1.053 5748 1237 3196 1 3 . 5 13 1/4LNN2 0 . 0 18 50 0 .0711 6 0 8 . 7 0 .9986 7 3 . 0 4 1 .053 4104 3 6 0 . 2 872 3 5 . 5 14 1/4LNN2 0 . 0 18 50 0 .0711 6 0 8 . 7 0 . 9 9 8 6 7 3 . 0 4 1.053 4104 3 6 0 . 2 790 4 9 . 0 15 1/4LNN2 0 . 0 18 100 0 .0711 852. 1 0 .9986 73 .04 1.053 5745 7 0 5 . 8 1076 32 . 1 16 •1/4LNN2 0 . 0 18 150 0 .0711 1028 0 . 9 9 8 6 7 3 . 0 4 1.053 6932 1027 1650 2 3 . 3 17 1/4LNN2 0 . 0 18 150 0 .0711 1028 0 . 9 9 8 6 7 3 . 0 4 1.053 6932 1027 753 2 5 . 3 18 1/4LNN2 0 . 0 18 200 0 .0711 1175 0 .9986 73 .04 1 .053 7922 1342 2096 1 5 . 5 19 1/4LNN2 0 . 0 18 200 0 .0711 1175 0 .9986 7 3 . 0 4 1 .053 7922 1342 606 24 . 0 20 1/4LNN2 0 . 0 18 200 0 .0711 1175 0 .9986 7 3 . 0 4 1 .053 7922 1342 502 32 . 4 21 1/4LNN2 0 . 0 18 3O0 0 . 0 7 1 1 1457 0 .9986 7 3 . 0 4 1 .053 9824 2064 4342 15 . 8 22 1/4LNN2 0 . 0 18 400 0 .0711 1547 0 .9986 7 3 . 0 4 1 .053 104 3 0 2326 334 1 2 0 . 1 2 3 1/4LNN2 0 . 0 19 400 0 . 0 7 1 1 1547 0 .9984 72 . 8 9 1 .027 10690 2331 1279 2 0 . a 24 1/4LNN2 0 . 0 24 550 0.0711 1889 0 . 9 9 7 3 72 . 13 0 . 9 1 1 14700 3502 916 2 0 . 3 25 1/4LNN2 0 . 0 23 550 0 . 0 7 1 1 1889 0 . 9 9 7 5 7 2 . 2 8 0 . 9 3 2 5 14370 3501 931 16 .6 SUMMARY OF EXPERIMENTAL RESULTS: P a r t I ( c o n t )  A t o m i z a t i o n of Water and G l y c e r o l / W a t e r M i x t u r e s T e s t No. N o z z l e G l y c e r o l " Water Weight Percent F l u i d Temp •c Atom. P r e s . p s i g O r i f i c e 0 lameter cm Uo cm/s Dens 1ty g/cra" a S u r f a c e T e n s i o n dynes/cm V i s e , c p Re We Drops Counted Mean Dlameter d i o ^m 26 1/4LNN2 0 . 0 21 560 0 .0711 1910 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 13860 3566 3766 18. 1 27 1/4LNN8 0 . 0 21 50 0 .1524 5 2 9 . 9 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 8241 5 8 8 . 3 498 7 7 . 8 28 1/4LNN8 0 . 0 21 50 0 .1524 5 2 9 . 9 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 8241 5 8 8 . 3 212 7 1 . 8 29 1/4LNN8 0 . 0 21 50 0 .1524 5 2 9 . 9 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 8241 5 8 8 . 3 282 68 . 4 30 1/4LNN8 0 . 0 21 too 0.1524 7 3 3 . 8 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 11410 1128 942 72 . 2 31 1/4LNN8 0 . 0 21 150 0 .1524 9 3 1 . 9 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 14490 1820 1367 57 .9 32 1/4LNN8 0 . 0 21 300 0 .1524 1334 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 20750 3729 565 5 8 . 7 33 1/4LNN8 0 . 0 21 300 0 .1524 1334 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 20750 3729 1002 68 . 2 34 1/4LNN8 0 . 0 21 510 0 .1524 1736 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 27000 6315 1096 4 4 . 8 35 1/4LNN8 0 . 0 21 500 0 .1524 1727 0 . 9 9 8 0 72 .59 0 . 9 7 8 26860 6249 1382 5 3 . 1 36 1/4LNN8 0 . 0 21 400 0 .1524 1544 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 24010 4995 2074 54 . 3 37 1/4LNN14 0 . 0 21 50 0 . 1 9 3 0 581 . 1 0 . 9 9 8 0 72 .59 0 . 9 7 8 11440 8 9 6 . 0 789 6 0 . 6 38 1/4LNN14 0 . 0 21 50 0 . 1 9 3 0 581 . 1 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 11440 8 9 6 . 0 1020 62 . 1 39 1/4LNN14 0 . 0 21 100 0 . 1 9 3 0 826. 1 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 16270 181 1 1520 3 9 . 0 40 1/4LNN14 0 . 0 21 150 0 . 1 9 3 0 1014 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 19970 2728 4065 4 1 . 4 4 1 1/4LNN26 0 . 0 21 50 0 .2184 8 0 5 . 3 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 17950 1947 1373 4 6 . 6 42 1/4LNN26 0 . 0 21 150 0 . 2 1 8 4 1401 0 . 9 9 8 0 7 2 . 5 9 0 . 9 7 8 31230 5894 3506 3 0 . 4 43 1/4LNN26 0 . 0 20 305 0 .2184 2002 0 .9982 72.74 1 .002 43560 12010 3431 28 . 3 44 1/4LNN26 0 . 0 20 310 0 .2184 2010 0 .9982 72.74 1 .002 43730 12110 3704 29. 1 45 1/4LNN14 0 . 0 20 340 0 . 1 9 3 0 1532 0 .9982 72 .74 1 .002 29460 6216 6700 32 . 1 46 1/4LNN14 0 . 0 19 325 0 . 1 9 3 0 1504 0 .9984 7 2 . 8 9 1 .027 28220 5980 3001 43 . 2 47 1/4LNN14 0 . 0 20 500 0 . 1 9 3 0 1834 0 .9982 72 .74 1 .002 35270 8908 1210 3 9 . 9 48 , t/4LNN14 0 . 0 20 475 0 . 1 9 3 0 1800 0 .9982 72.74 1 .002 34610 8581 1349 42 . 1 49 1/4LNN14 0 . 0 20 475 0 . 1 9 3 0 1800 0 .9982 72 .74 1 .002 34610 8581 2222 54 . 3 50 1/4LNN2 8 9 . 7 23 500 0 . 0 7 1 1 2687 1 . 232 6 4 . 3 205 114.8 9836 507 53 . 3 SUMMARY OF EXPERIMENTAL RESULTS: P a r t I ( c o n t )  A t o m i z a t i o n o f Water and G l y c e r o l / W a t e r M i x t u r e s T e s t No. N o z z l e G l y c e r o l Water Weight Percent F l u i d Temp - C Atom. P r e s . p s i g O r i f i c e 0 tameter cm Uo cm/s Oens1 t y g/cra' a S u r f a c e T e n s i o n dynes/cm C V i s e , c p Re We Drops Counted Mean D 1 a m e t e r d . o pni 51 1/4LNN2 8 9 . 7 23 500 0 . 0 7 1 1 2687 1.232 6 4 . 3 205 114.8 9836 1300 37 .8 52 1/4LNN8 8 9 . 7 23 460 0 .1524 1827 1.232 6 4 . 3 205 167.3 9747 3286 5 6 . 2 53 1/4LNN14 8 9 . 7 23 460 0 . 1 9 3 0 1709 1.232 6 4 . 3 205 198.2 10800 1491 58 .9 54 1/4LNN26 89.7 23 350 0 .2184 1913 1.232 6 4 . 3 205 251. 1 15310 82 5 6 . 2 55 1/4LNN26 8 2 . 5 23 350 0 .2184 2091 1.213 6 5 . 3 6 8 . 0 8 1 4 . 6 17740 668 5 0 . 2 56 1/4LNN8 8 2 . 5 22 325 0 .1524 1407 1.214 6 5 . 2 6 8 . 0 382 .8 5618 1635 62 . 3 57 1/4LNN8 8 2 . 5 22 430 0 .1524 1608 1.214 6 5 . 2 6 8 . 0 4 3 7 . 5 7337 631 5 3 . 5 58 I/4LNN8 8 2 . 5 22 475 0 .1524 1690 1.214 6 5 . 2 6 8 . 0 4 5 9 . 8 8105 611 6 8 . 7 59 1/4LNN2 8 2 . 5 22 275 0 . 0 7 1 1 1889 1.214 6 5 . 2 6 8 . 0 239.8 4724 2534 4 9 . 0 60 1/4LNN2 8 2 . 5 22 475 0 .0711 2645 1.214 6 5 . 2 6 8 . 0 335.7 9262 17 10 5 5 . 5 61 1/4LNN2 8 2 . 5 22 550 0 . 0 7 1 1 2771 1.214 6 5 . 2 6 8 . 0 351 .7 10170 1906 47 . 1 62 1/4LNN14 8 2 . 5 22 230 0 . 1 9 3 0 1231 1.214 6 5 . 2 6 8 . 0 424 . 2 5446 777 64 . 7 63 1/4LNN14 8 2 . 5 22 350 0 . 1 9 3 0 1493 1.214 6 5 . 2 6 8 . 0 514.4 8010 1938 5 3 . 0 64 1/4LNN14 8 2 . 5 22 525 0 . 1 9 3 0 1874 1.214 6 5 . 2 6 8 . 0 645 .7 12620 2734 44 . 9 65 1/4LNN14 8 2 . 5 22 525 0 . 1 9 3 0 1874 1.214 6 5 . 2 6 8 . 0 645 .7 12620 990 4 0 . 7 66 1/4LNN26 8 2 . 5 22 210 0 .2184 1513 1.214 6 5 . 2 6 8 . 0 5 8 9 . 9 9309 1 171 52 . 1 67 1/4LNN26 8 2 . 5 22 300 0 .2184 1980 1.214 6 5 . 2 6 8 . 0 7 7 2 . 0 15940 1003 5 8 . 2 68 1/4LNN26 8 2 . 5 22 450 0 . 2184 2491 1.214 6 5 . 2 6 8 . 0 9 7 1 . 3 25230 2956 48 . 4 69 1/4LNN.6 8 2 . 5 22 625 0 . 0 4 0 6 1867 1.214 6 5 . 2 6 8 . 0 135.3 2635 17B4 33 . 9 70 1/4LNN.6 64 .8 23 570 0 . 0 4 0 6 1892 1 . 165 6 7 . 5 14.7 6 0 8 . 8 2508 2403 5 5 . 6 71 1/4LNN.6 64 .8 23 350 0 . 0 4 0 6 1339 1 . 165 6 7 . 5 14.7 430 .8 1256 2590 52 . 5 72 1/4LNN2 64 a 23 100 0 .0711 1007 1 . 165 67 .5 14.7 567.4 1244 2430 67 .6 73 .1/4LNN2 64 .8 23 195 0 .0711 1352 1 . 165 6 7 . 5 14.7 761 .8 2243 2516 48 .6 74 1/4LNN2 6 4 . 8 23 310 0 .0711 1637 1 . 165 6 7 . 5 14 . 7 9 2 2 . 4 3288 4151 27 . 1 75 1/4LNN2 64 .8 23 450 0 .0711 1931 1 . 165 6 7 . 5 14.7 1088 4576 1233 18 . 9 SUMMARY OF EXPERIMENTAL RESULTS: P a r t I ( c o n t ) A t o m i z a t i o n of Water and G l y c e r o l / W a t e r M i x t u r e s T e s t No. N o z z l e G l y c e r o l Water Weight P e r c e n t F l u i d Temp °C Atom. P r e s . p s i g Or i f Ice D iameter cm Uo cm/s P D e n s i t y g/cm' 0 S u r f a c e T e n s i o n dynes/cm r V i s e , cp Re We Drops Counted Mean D iameter d i » i*m 76 1/4LNN2 6 4 . 8 23 435 0 .0711 1910 1. 165 6 7 . 5 14.7 1076 4477 3733 2 6 . 5 77 1/4LNN2 64 .8 23 575 0 .0711 2120 1. 165 6 7 . 5 14.7 1195 5515 3969 2 4 . 7 78 1/4LNN8 6 4 . 8 23 95 0 .1524 731 1. 165 6 7 . 5 14.7 8 8 2 . 9 1405 1867 3 0 . 2 79 1/4LNN8 6 4 . 8 23 300 0 .1524 1270 1. 165 6 7 . 5 14.7 1534 4242 2809 4 9 . 2 80 1/4LNN8 6 4 . 8 23 300 0 .1524 1270 1. 165 6 7 . 5 14.7 1534 4242 1350 3 8 . 0 81 1/4LNN8 6 4 . 8 23 575 0 .1524 1681 1. 165 6 7 . 5 14.7 2030 7433 3307 4 2 . 8 82 1/4LNN14 6 4 . 8 23 95 0 . 1 9 3 0 798 1. 165 6 7 . 5 14.7 1221 2121 1652 58 . 1 83 1/4LNN14 6 4 . 8 23 320 0 . 1 9 3 0 1481 1. 165 6 7 . 5 14.7 2265 7306 2042 4 6 . 5 84 1/4LNN14 6 4 . 8 23 500 0 . 1 9 3 0 1766 1. 165 6 7 . 5 14.7 2701 10390 3385 54 . 3 85 1/4LNN26 6 4 . 8 23 100 0 .2184 1023 1. 165 6 7 . 5 14.7 1771 3945 233 57 . 7 86 1/4LNN26 6 4 . 8 23 110 0 .2184 1045 1. 165 6 7 . 5 14.7 1809 4116 2902 37 . 7 87 1/4LNN26 64 .8 23 300 0 .2184 1869 1. 165 6 7 . 5 14.7 3235 13170 2196 5 9 . 8 88 1/4LNN26 6 4 . 8 23 470 0 .2184 2447 1. 165 6 7 . 5 14.7 4235 22570 1658 4 7 . 6 TABLE V - 4 SUMMARY OF EXPERIMENTAL RESULTS: P a r t II  A t o m i z a t i o n of Water and Superheated Water T e s t N o . N o z z l e Water Temp •C Atom. P r e s . p s i g O r i f I c e D iameter cm Samp1e L o c a t ' n Uo cra/s f D e n s i t y g/cm' a S u r f a c e T e n s i o n dynes/cm v i s e , cp Re We Drops Counted Mean Diameter d i • „ra 89 1/4LNN.6 86 153 0 .0406 c e n t e r 875 0 .968 6 1 . 5 0 . 3 3 10420 489 4207 2 4 . 9 90 1/4LNN.6 100 150 0 .0406 c e n t e r 870 0 . 9 5 8 5 8 . 9 0 . 2 5 13520 500 2803 27 .7 91 1/4LNN.6 120 154 0 .0406 c e n t e r 875 0 .944 5 5 . 2 0 . 19 17650 532 2941 16.6 92 1/4LNN.6 149 155 0 .0406 c e n t e r 875 0 . 9 2 6 4 9 . 9 0 . 125 26320 576 1016 16.2 93 1/4LNN2 127 105 0 .0711 cone 877 0 . 9 4 0 5 4 . 0 0 . 17 34580 952 958 57 .8 94 1/4LNN2 146 105 0 .0711 cone 877 0 . 9 2 6 5 0 . 5 O. 13 44420 1003 1384 5 7 . 7 95 1/4LNN2 148 110 0 :0711 c e n t e r 882 0 . 9 2 5 5 0 . 1 0 . 13 44620 1021 6410 17.8 96 1/4LNN2 85 107 0 .0711 c e n t e r 879 0 . 9 6 9 6 1 . 7 0 . 3 2 18730 863 3425 17.2 97 1/4LNN2 85 105 0 .0711 cone 877 0 . 9 6 9 6 1 . 7 0 . 3 2 18880 859 1692 30 .4 98 1/4LNN2 102 105 0.0711 c e n t e r 877 0 . 9 5 7 5 8 . 6 0 . 2 5 23870 893 2737 16. 1 99 1/4LNN2 104 107 0 .0711 cone 879 0 . 9 5 6 5 8 . 2 0 . 2 4 24890 902 894 4 9 . 1 too 1/4LNN2 126 110 0 .0711 c e n t e r 882 0 . 9 4 0 5 4 . 1 0 . 18 32820 961 1689 16.8 101 1/4LNN2 126 110 0 .0711 cone 882 0 . 9 4 0 5 4 . 1 0 . 18 32820 961 1016 8 6 . 0 102 1/4LNN8 84 130 0 . 1524 c e n t e r 861 0 . 9 6 9 6 1 . 8 0 . 3 2 39720 1770 2145 15.8 103 1/4LNNS 87 134 0.1524 cone 886 0 . 9 6 7 6 1 . 3 0 . 3 3 39580 1890 3444 4 4 . 5 104 ..1/4LNN8 105 125 0 .1524 cone 850 0 . 9 5 5 5 8 . 0 0 . 2 5 49480 1813 2027 5 1 . 1 105 1/4LNN8 127 109 0.1524 c e n t e r 804 0 . 9 4 0 5 4 . 0 0 . 17 67750 1715 1432 15.2 106 1/4LNN8 130 127 0.1524 c e n t e r 859 0 . 9 3 8 5 3 . 4 0 . 17 72220 1975 1142 2 0 . 8 107 1/4LNN8 130 129 0 .1524 cone 859 0 .938 5 3 . 4 0 . 17 72220 1975 578 3 3 . 4 108 1/4LNN14 120 99 0 . 1 9 3 0 ..center 820 0 .944 5 5 . 2 0 . 19 78670 2219 134 1 13.2 109 1/4LNN14 120 103 0 . 1 9 3 0 cone 843 0 .944 5 5 . 2 0 . 19 80840 2346 1292 4 2 . 3 1 10 I/4LNN14 120 82 0 . 1 9 3 0 c e n t e r 740 0.944 5 5 . 2 0 . 19 70960 1807 1 108 13.9 11 1 ' 1/4LNN14 116 82 0 . 1 9 3 0 cone 740 0 . 9 4 8 5 6 . 0 0 . 2 0 67600 1789 2422 4 0 . 5 112 1/4LNN14 1 16 125 0 . 1 9 3 0 c e n t e r 911 0 .948 5 6 . 0 0 . 2 0 83340 27 1 1 1038 40 . 2 113 1/4LNN14 1 16 125 0 . 1 9 3 0 cone 91 1 0 . 9 4 8 5 6 . 0 0 . 2 0 83340 27 1 1 336 8 3 . 4 1 14 1/4LNNia; 1 16 123 0 . 1 9 3 0 cone 911 0 .948 56 . 0 0 . 20 83340 271 1 663 7 5 . 0 SUMMARY OF EXPERIMENTAL RESULTS: Par t II ( c o n t ) A t o m i z a t i o n of Water and Superheated Water T e s t No . N o z z l e Water Temp •c Atom. P r e s . p s i g O r i f i c e D iameter cm Sample L o c a t ' n Uo cm/s •, P Oensi ty g/cm' a S u r f a c e Tens i o n dynes/cm * V i s e , c p Re We Drops Counted Mean D iameter d i o pro 1 IS 1/4LNN26 88 50 0 .2184 c e n t e r 805 0 .967 6 1 . 1 0 . 3 1 54840 ' 2240 1062 16.4 1 16 1/4LNN26 88 50 0 .2184 cone 805 0 .967 6 1 . 1 0 . 3 1 54840 2240 3163 4 5 . 9 1 17 1/4LNN26 119 55 0 .2184 cone 850 0 . 9 4 6 5 5 . 4 0 . 19 92430 2690 353 44 . 0 1 18 1/4LNN26 119 55 0 .2184 c e n t e r 850 0 .946 5 5 . 4 0 . 19 92430 2690 1134 3 0 . 4 1 19 1/4LNN26 121 55 0 .2184 cone 850 0 .944 5 5 . 1 0 . 18 97360 2700 2126 5 2 . 2 120 1/4LNN26 138 48 0 .2184 c e n t e r 796 0 . 9 3 3 5 1 . 9 0 . 15 108100 2490 2158 2 9 . 9 121 1/4LNN26 135 48 0 .2184 c e n t e r 796 0 . 9 3 5 5 2 . 5 0 . 15 108100 2460 1367 3 0 . 6 122 1/4LNN26 136 48 0 .2184 cone 796 0 .934 5 2 . 3 O. 15 108100 2470 589 72 . 5 123 1/4LNN26 136 53 0 .2184 cone 832 0 .934 5 2 . 3 0 . 15 113100 2700 1213 73 8 124 1/4LNN2 96 50 0 .0711 c e n t e r 609 0 .961 5 9 . 6 0 . 2 7 15410 425 2062 38 . 0 125 1/4LNN2 96 50 0 .0711 cone 609 0 .961 5 9 . 6 0 . 2 7 15410 425 847 85 . 3 126 1/4LNN2 97 150 0 .0711 c e n t e r 1028 0 .961 5 9 . 6 0 . 2 7 26020 1218 1260 2 5 . 6 127 1/4LNN2 98 150 0 .0711 cone 1028 0 . 9 6 0 5 9 . 3 0 . 2 7 16020 1218 498 71 .8 128 1/4LNN2 98 380 0 .0711 c e n t e r 1595 0 . 9 6 0 5 9 . 3 0 . 2 7 40320 2930 1081 t 3 . 0 129 1/4LNN2 98 380 0 .0711 cone 1595 0 . 9 6 0 5 9 . 3 0.-27 40320 2930 653 5 0 . 8 ISO 1/4LNN2 98 385 0 . 0 7 11 cone 1595 0 . 9 6 0 5 9 . 3 0 . 27 40320 2930 635 62 . 7 TABLE V - 5 SUMMARY OF EXPERIMENTAL RESULTS: P a r t H I A t o m i z a t i o n of C o n c e n t r a t e d B l a c k L i q u o r <n S p r a y i n g Systems 1/4LNN2 G r o o v e d - C o r e N o z z l e T e s t No. B l a c k L Iquor S o l Ids % L iquor Temp » C Atom. P r e s . p s i g Uo cm/s D e n s i t y g/cm' a S u r f a c e T e n s i o n dynes/cm P V i s e , c p Re We Drops Counted Mean D iameter d i o „m Comments 131 5 6 . 3 102 185 1322 1.31 35 4 6 . 0 268 4650 2729 6 0 . 3 132 5 6 . 3 108 175 1280 1.31 35 3 7 . 0 332 4360 782 113.8 133 56 . 3 135 170 1257 1.31 35 8 . 5 1377 4210 364 126.7 134 5 6 . 3 112 195 1343 1.31 35 2 7 . 3 458 4800 1589 9 5 . 8 135 5 6 . 3 134 205 Poor Atom. 136 56 . 3 136 195 Poor Atom. 137 5 6 . 3 110 180 Poor Atom. 138 5 6 . 3 121 380 Poor Atom. 139 5 6 . 3 121 210 1393 1.31 35 1 7 . 5 741 5160 1408 8 4 . 2 140 5 6 . 3 120 210 1393 1.31 35 1 8 . 9 720 5160 245 6 5 . 1 141 5 6 . 3 102 4 10 1721 1.31 35 4 6 . 0 348 7880 871 9 0 . 6 142 56 . 3 101 520 2057 1.31 35 4 8 . 0 399 1 1260 1320 8 3 . 5 143 5 5 . 2 100 195 1343 1.31 35 3 7 . 0 338 4800 904 105 .0 144 5 5 . 2 102 190 1339 1.31 35 3 4 . 0 367 4800 97 166.9 145 5 5 . 2 100 190 1339 1.31 35 3 7 . 0 337 4800 1811 117.4 146 . . 5 5 . 2 134 190 1339 1.31 35 7 . 8 1560 4800 385 128.2 Some f l a s h . 147 5 5 . 2 135 200 1364 1.31 35 7 . 5 1694 4950 1504 9 1 . 2 148 5 5 . 2 133 190 1339 1.31 35 8 . 3 1503 67O0 418 134.3 Some f l a s h . 149 5 5 . 2 1 19 195 1343 1.31 35 1 5 . 5 807 4800 648 144 . 3 150 5 5 . 2 120 195 1343 1.31 35 1 5 . 0 833 480O 368 133.0 151 5 5 . 2 1 18 200 1364 1.31 35 16.2 784 4950 626 128.4 152 5 5 . 2 135 200 Poor Atom. 153 ' 55 . 2 136 200 Poor Atom. 154 5 5 . 2 133 205 Poor Atom. 155 5 5 . 2 . 120 200 1364 1.31 35 1 5 . 0 847 4950 604 114.8 156 5 5 . 2 •- 1 15 200 1364 1.31 35 18.6 683 4950 161 1 97 .4 TABLE V - 6 SUMMARY OF EXPERIMENTAL RESULTS: Par t IV Mean D i a m e t e r s Dete rmined from E x p e r i m e n t a l Data T e s t NO. N o z z l e L i q u i d Used L i q u i d Temp. •c Atom. P r e s . p s i g Sample L o c a t ' n Mean D i a m e t e r s ( m i c r o n s ) D e v i a t ions d 11 d l a d i o d . i d geom d s q r t Geo . S q . R t . 162 1/4LNN.6 water 17 50 c e n t e r 5 9 . 9 7 6 . 7 9 2 . 6 135.2 4 5 . 2 7 . 2 0 2 . 12 7 . 76 38.4 1/4LNN.6 water 17 100 c e n t e r 5 0 . 5 6 5 . 9 79 . 3 115.0 3 3 . 5 6 . 5 0 2 .73 8 . 4 5 5 1/4LNN.6 water 17 150 c e n t e r 3 9 . 1 4 8 . 3 5 6 . 3 7 6 . 3 2 9 . 6 5 . 8 5 2 . 16 4 .83 6&7 1/4LNN.6 water 17 200 c e n t e r 2 6 . 8 3 2 . 3 38. 1 5 3 . 0 2 2 . 4 4 . 9 5 1 .80 2 . 39 8 1/4LNN.6 water 17 300 c e n t e r 19.5 2 1 . 6 2 3 . 8 2 8 . 9 17 .7 4 . 3 1 1 .54 0 . 9 4 9610 1/4LNN.6 water 18 400 c e n t e r 16.4 18.6 2 1 . 0 2 6 . 7 14 .2 3 . 9 1 1 .72 1 .08 1 1612 1/4LNN.6 water 18 550 c e n t e r 13.3 15. 1 17.2 2 2 . 4 1 1 . 9 3 . 5 5 1 .58 0 . 74 13614 1/4LNN2 water 18 50 cone 4 1 . 9 5 2 . 1 6 1 . 7 8 6 . 8 3 2 . 9 6 . 0 9 2 .01 4 . 77 15 1/4LNN2 water 18 100 cone 32 . 1 3 7 . 3 4 2 . 7 5 5 . 7 2 7 . 6 5 . 4 5 1 . 73 2 . 39 166 17 1/4LNN2 water 18 150 cone 23 .9 2 6 . 5 2 9 . 2 3 5 . 3 2 1 . 5 4 . 7 7 1 .59 1 . 24 1 8 - 2 0 1/4LNN2 water 18 200 cone 19.7 2 2 . 6 2 5 . 8 3 3 . 6 1 7 . 3 4 . 29 1 .64 1 . 28 2 1 1/4LNN2 water IB 300 cone 15.8 17 .5 19. 7 2 5 . 0 14.4 3 . 8 8 1 .52 0 . 7 5 22623 1/4LNN2 water 18 400 cone 2 0 . 3 2 3 . 2 2 7 . 4 3 8 . 2 1 8 . 3 4 . 3 8 1 . 54 1 . 10 24625 1/4LNN2 water 23 550 cone 18.4 2 0 . 5 2 3 . 2 2 9 . 6 1 6 . 9 4 . 2 0 1 .48 0 . 8 1 26 1/4LNN2 water 21 560 cone 18. 1 2 0 . 3 2 3 . 8 3 2 . 4 16 .6 4 . 16 1 .47 0 . 8 2 2 7 - 2 9 1/4LNN8 water 21 50 cone 7 3 . 9 ' 9 8 . 1 120.6 182.5 48 . 5 7 .82 2 . 7 4 12 . 77 30 1/4LNN8 water 21 100 cone 7 2 . 2 ' 8 7 . 4 100 .0 130.9 5 3 . 3 7 . 9 5 2 . 40 8 . 9 7 31 1/4LNN8 water 21 150 cone 57 .9 6 9 . 2 7 8 . 4 100.4 44 . 0 7 . 16 2 . 28 6 . 6 7 32633 1/4LNN8 water 21 300 cone 64 .8 7 1 . 5 7 7 . 5 9 1 . 1 5 6 . 2 7 . 8 0 1 .82 3 95 34 1/4LNN8 water 21 510 cone 4 4 . 8 5 9 . 1 78. 1 136.7 3 1 . 7 6 . 18 2 . 46 6 . 5 9 35 1/4LNN8 water 21 500 cone 5 3 . 1 7 1 . 7 9 0 . 8 145.6 3 5 . 0 6 . 2 4 2 . 6 9 9 . 19 36 1/4LNN8 water 21 400 cone 54 . 3 7 0 . 0 8 6 . 6 132 .6 3 9 . 0 6 . 8 2 2 . 38 7 .53 37638 1/4LNN14 water 2 1 50 cone 6 1 . 5 8 5 . 8 1 10.8 184 .9 4 1 . 3 7 .11 2 . 47 10 89 SUMMARY OF EXPERIMENTAL RESULTS: Par t IV ( c o n t ) Mean D i a m e t e r s Determined from E x p e r i m e n t a l Data T e s t No. Nozz1e L1qu1d Used L1qu1d Temp. °C Atom. P r e s . p s i g Sample L o c a t ' n Mean D i a m e t e r s (mic rons ) D e v l a t I o n s d i o d i o di o d i > d georo d s q r t Geo . S q . R t . 39 1/4LNN14 water 21 100 cone 3 9 . 0 5 6 . 6 7 7 . 6 145.7 2 6 . 3 5 . 6 5 2 . 3 9 7 . 0 0 40 1/4LNNI4 water 21 150 cone 4 1 . 4 6 0 . 0 8 0 . 0 142.2 2 7 . 2 5 . 7 9 2 . 4 8 7 . 8 0 4 i 1/4LNN26 water 21 50 cone 4 6 . 6 70 . 7 100.6 2 0 3 . 6 2 9 . 5 6 . 10 2 .62 9 . 4 9 42 1/4LNN26 water 21 150 cone 3 0 . 4 4 5 . 1 6 3 . 7 126.7 2 0 . 4 4 . 9 3 2 .41 5 .61 43S44 1/4LNN26 water 20 305 cone 2 8 . 7 4 4 . 1 6 6 . 0 148 .0 19.6 4 . 8 5 2 . 32 5 . 2 0 45 1/4LNN14 water 20 340 cone 32 . 1 4 8 . 0 7 3 . 3 170.6 2 3 . 8 5 . 2 2 2 .04 4 . 78 46 1/4LNN14 water 19 325 cone 4 3 . 2 61 . 0 82 . 7 152. 1 3 1 . 8 6 . 0 6 2 . 0 6 6 . 5 0 47 1/4LNN14 water 20 500 cone 3 9 . 9 5 0 . 9 6 6 . 2 111.7 3 2 . 6 5 . 9 9 1.81 4 .04 4B&49 1/4LNN14 water 20 475 cone 4 9 . 7 7 0 . 3 9 6 . 5 181 . 9 3 7 . 0 6 . 5 2 2 .02 7 . 28 50 1/4LNN2 89.7% g/w 23 500 cone 5 3 . 3 8 1 . 6 119.2 2 5 3 . 9 3 6 . 8 6 . 6 2 2 . 2 2 9 . 5 9 SI 1/4LNN2 89. 7% g/w 23 500 cone 3 7 . 8 6 2 . 8 113. 1 3 6 6 . 4 2 9 . 7 5 . 7 2 1.79 5 . 0 9 52 1/4LNN8 89.7% g/w 23 460 cone 5 6 . 2 8 3 . 0 124.6 281 1 4 2 . 3 6 . 9 3 1 .97 8 . 10 53 1/4LNN14 89.7% g/w 23 460 cone 5 8 . 9 8 2 . 7 110. 1 194.9 4 2 . 2 7 .04 2 . 18 9 . 34 54&5S 1/4LNN26 82.5% g/w 23 350 cone 5 0 . 9 7 5 . 3 100.2 177 . 0 2 9 . 6 6 . 2 9 3 . 0 3 1 1 . 29 56 1/4LNN8 82.5% g/w 22 325 cone 6 2 . 3 7 5 . 7 8 9 . 3 124 . 1 5 0 . 4 7 . 4 9 1 .93 6 . 23 57 1/4LNN8 82.5% g/w 22 430 cone 5 3 . 5 6 1 . 2 6 9 . 4 8 9 . 4 4 6 . 6 7 . 0 7 1 .69 3 . 5 3 58 1/4LNN8 82.5% g/w 22 475 cone 6 8 . 7 7 5 . 0 8 1 . 4 9 5 . 8 6 2 . 6 8 . 10 1 . 56 3 .08 59 1/ 1LNN2 82.5% g/w 22 275 cone 4 9 . 0 7 0 . 8 102 . 1 2 1 2 . 7 3 6 . 9 6 . 4 8 1 . 9 9 7 .01 60 1/4LNN2 82.5% g/w 22 475 cone 5 5 . 5 7 6 . 5 102.3 182 .6 4 1 . 3 6 . 8 9 2 .08 7 .91 61 1/4LNN2 82.5% g/w 22 550 cone 47. 1 7 0 . 4 101 .4 210. 1 3 4 . 3 6 . 2 9 2 .05 7 . 5 0 62 1/4LNN14 82.5% g/w 22 230 cone 6 4 . 7 7 9 . 0 95 . 3 138.6 52 . 3 7 .64 1 . 95 6 . 44 63 1/4LNN14 82.5% g/w 22 350 cone 5 3 . 0 74 . 2 9 8 . 3 172 . 7 38 . 1 6 . 6 8 2 . 17 8 . 36 64&65 I/4LNN14 82.5% g/w 22 525 cone 4 3 . 8 6 2 . 4 88 . 5 178.0 3 2 . 3 6 . 10 2 . 0 6 6 . 57 SUMMARY OF EXPERIMENTAL RESULTS: P a r t IV ( c o n t ) Mean D i a m e t e r s Determined from E x p e r i m e n t a l Data Tes t NO. NozzIe L i q u i d Used L i q u i d Temp. °C Atom. P r e s . p s i g Sample L o c a t ' n Mean D i a m e t e r s ( m i c r o n s ) D e v i a t ions d i o d i e d i o d i . d geom d s q r t Geo. S q . R t . 66 1/4LNN26 82.5% g/w 22 210 cone 52 . 1 6 9 . 6 8 5 . 9 130.8 3 6 . 4 6 .61 2 . 34 8 . 4 2 67 1/4LNN26 82.5% g/w 22 300 cone 5 8 . 2 7 6 . 5 9 3 . 9 141.3 4 1 . 2 7.02 2 . 33 8 . 9 6 68 I/4LNN26 82.5% g/w 22 450 cone 48 . 1 6 9 . 4 9 4 . 4 174 .4 3 4 . 5 6 . 3 5 2 . 14 7 . 8 1 69 1/4LNN.6 82.5% g/w 23 625 c e n t e r 3 3 . 9 5 1 . 0 7 8 . 5 186.4 2 6 . 0 5 . 4 0 1 .88 4 . 76 70 1/4LNN.6 64.8% g/w 23 570 c e n t e r 5 5 . 6 7 6 . 8 101.6 178.0 4 1 . 3 6 . 8 9 2 .05 8 .09 7 1 I/4LNN.6 64.8% g/w 23 350 c e n t e r 5 2 . 5 6 3 . 5 7 5 . 3 106. 1 4 3 . 4 6 . 9 0 1 .82 4 .82 72 1/4LNN2 64.8% g/w 23 100 cone 6 7 . 6 8 7 . 3 108.3 166.7 5 1 . 6 7 .68 2 .06 8 . 6 2 73 1/4LNN2 64.8% g/w 23 195 cone 4 8 . 6 5 4 . 5 6 0 . 6 7 5 . 2 4 3 . 5 6 .78 1 .59 2 . 6 7 74 I/4LNN2 64.8% g/w 23 310 cone 2 7 . 1 2 9 . 5 3 2 . 3 3 8 . 7 2 5 . 0 5 . 10 1 .47 1 . 0 8 75 I/4LNN2 64.8% g/w 23 450 cone 18 .9 2 0 . 6 2 3 . 4 3 0 . 4 17.6 4 .27 1 .42 0 . 6 6 76 I/4LNN2 64.8% g/w 23 435 cone 2 6 . 5 2 8 . 7 3 1 . 2 37 . 0 2 4 . 5 5 . 0 5 1 .47 1 .01 77 1/4LNN2 64.8% g/w 23 575 cone 2 4 . 7 2 6 . 0 2 7 . 7 31 .4 2 3 . 6 4.91 1 . 33 . 56 78 I/4LNN8 64.8% g/w 23 95 cone 3 0 . 2 4 4 . 8 6 4 . 8 135.9 22 .4 5 . 0 5 1 .98 4 6 3 79S80 I/4LNN8 64.8% g/w 23 300 cone 4 5 . 6 6 5 . 3 92 . 0 182 . 3 34 . 2 6 .24 1 .99 6 . 6 1 81 I/4LNN8 64.8% g/w 23 575 cone 4 2 . 8 5 1 . 5 6 1 . 4 8 7 . 2 3 5 . 8 6 . 2 5 1 .79 3 . 7 3 82 I/4LNN14 64.8% g/w 23 95 cone 58 . 1 76. 7 97 . 2 156.3 4 4 . 3 7.11 2 .03 7 . 6 2 83 1/4LNN14 64.8% g/w 23 320 cone 4 6 . 5 5 8 . 7 7 2 . 3 109.7 3 6 . 9 6 . 4 3 1 .94 5 . 16 84 1/4LNNI4 64.8% g/w 23 500 cone 54 . 3 7 0 . 9 91 . 0 150.0 4 2 . 5 6 .91 1 .94 6 .49 8 5 1/4LNN26 64.8% g/w 23 100 cone 5 7 . 7 6 8 . 7 81 . 9 1 16. 1 4 9 . 1 7 .29 1 . 73 4 . 5 9 8 6 I/4LNN26 6 4 . 8 % g/w 23 110 cone 37 . 7 5 2 . 2 7 6 . 7 165.8 3 0 . 8 5 . 8 0 1 . 75 4 . 0 1 87 1/4LNN26 64.8% g/w 23 300 cone 5 9 . 8 6 9 . 2 7 9 . 9 106.5 5 1 . 1 7.44 1 . 7 9 4 . 4 2 88 I/4LNN26 6 4 . 8 % g/w 23 4 70 cone 4 7 . 6 52 . 3 56 .6 6 6 . 3 4 2 . 5 6 .72 1 65 2 . 5 1 8 9 I/4LNN.6 water 86 153 c e n t e r 24 .9 2 9 . 8 3 5 . 9 52 . 1 2 1.1 4 .79 1 7 6 2 . 0 4 SUMMARY OF EXPERIMENTAL R E S U L T S : P a r t IV ( c o n t ) M e a n D i a m e t e r s D e t e r m i n e d f r o m E x p e r i m e n t a l D a t a T e s t N o . N o z z l e L i q u i d U s e d L i q u i d Temp . °C A t o m . P r e s . p s i g S a m p l e L o c a t ' n M e a n D i a m e t e r s ( m i c r o n s ) D e v i a t i o n s d i o d i o d i o d i • d geora d s q r t G e o . S q R t 9 0 1 / 4 L N N . 6 w a t e r too 150 c e n t e r 2 7 . 7 31 . 4 3 5 . 4 4 4 . 9 24 . 5 5 . 1 1 1 . 6 4 1 69 91 I / 4 L N N . 6 w a t e r 120 154 c e n t e r 1 6 . 6 1 7 . 4 1 8 . 3 2 0 . 2 1 5 . 8 4 . 02 1 . 3 7 0 . 387 9 2 1 / 4 L N N . 6 w a t e r 146 155 c e n t e r 1 6 . 2 1 6 . 7 17 . 1 1 7 . 9 1 5 . 8 4 .01 1 . 25 0 . 20 9 3 1 / 4 L N N 2 w a t e r 127 105 c o n e 5 7 . 8 6 3 . 6 7 1 . 5 9 0 . 2 5 1 . 0 7 . 4 0 1 . 7 8 3 . 0 9 94 1 / 4 L N N 2 w a t e r 146 105 c o n e 5 7 . 7 6 2 . 3 6 6 . 5 7 6 . 0 5 2 . 8 7 . 4 4 1 . 5 6 2 . 4 1 9 5 1 / 4 L N N 2 w a t e r 148 110 c e n t e r 1 7 . 8 1 9 . 7 2 2 . 3 2 8 . 4 1 6 . 3 4 . 1 3 1 . 5 3 0 . 8 1 96 1 / 4 L N N 2 w a t e r 8 5 107 c e n t e r 1 7 . 2 1 8 . 9 2 1 . 2 2 6 . 7 1 5 . 9 4 . 0 6 1 . 4 8 0 . 70 97 1 / 4 L N N 2 w a t e r 8 5 105 c o n e 3 0 . 4 3 2 . 8 3 5 . 4 4 1 . 1 2 8 . 2 5 . 4 1 1 . 48 1 . 15 98 1 / 4 L N N 2 w a t e r 102 105 c e n t e r 16 . 1 1 7 . 3 1 8 . 6 2 1 . 5 1 5 . 0 3 . 9 4 1 . 4 7 0 . 57 9 9 1 / 4 L N N 2 w a t e r 104 107 c o n e 4 9 . 1 5 5 . 7 6 2 . 0 7 6 . 8 4 2 . 5 6 . 7 7 1 . 7 3 3 . 34 100 1 / 4 L N N 2 w a t e r 125 1 to c e n t e r 1 6 . 8 1 8 . 4 2 0 . 0 2 3 . 6 1 5 . 3 4 . 0 1 1 . 5 5 0 . 7 6 101 1 / 4 L N N 2 w a t e r 126 110 c o n e 8 6 . 6 1 1 2 . 2 1 3 5 . 2 1 9 6 . 5 6 2 . 2 8 . 5 9 2 . 30 12 . 79 102 1 / 4 L N N 8 w a t e r 8 4 130 c e n t e r 1 5 . 8 1 6 . 9 1 8 . 7 2 3 . 0 1 5 . 0 3 . 9 2 1 . 37 0 . 43 103 1 / 4 L N N 8 w a t e r 87 134 c o n e 4 4 . 5 5 9 . 5 7 5 . 6 1 2 2 . 0 3 3 . 5 6 . 2 0 2 . 0 5 6 . 0 9 104 1 / 4 L N N 8 w a t e r 105 125 c o n e 5 1 . 1 6 9 . 5 . 8 8 . 2 14 1 . 9 3 6 . 9 6 . 5 8 2 . 17 7 . 8 2 105 1 / 4 L N N 8 w a t e r 109 127 c e n t e r 1 5 . 2 1 6 . 6 1 8 . 7 2 3 . 5 14 . 1 3 . 8 3 1 . 5 0 0 . 59 106 I / 4 L N N 8 w a t e r 127 130 c e n t e r 2 0 . 8 2 2 . 4 2 4 . 2 2 8 . 3 1 9 . 4 4 . 4 8 1 . 4 4 0 . 7 3 107 1 / 4LNNS w a t e r 129 130 c o n e 3 3 . 7 4 6 . 6 5 7 . 7 8 8 . 2 2 3 . 2 5 . 2 8 2 . 2 7 5 . 9 0 108 1 / 4 L N N 1 4 w a t e r 9 9 120 c e n t e r 1 4 . 7 1 6 . 4 1 9 . 0 2 5 . 6 1 3 . 2 3 . 7 3 1 . 56 0 . 734 109 1 / 4 L N N 1 4 w a t e r 103 120 c o n e 4 2 . 3 5 7 . 5 7 1 . 5 1 1 0 . 4 2 9 . 1 5 . 9 3 2 . 40 7 . 1 1 1 10 1 / 4 L N N 1 4 w a t e r 8 2 120 c e n t e r 1 3 . 9 1 4 . 8 15 . 7 1 7 . 9 13 . t 3 . 6 7 1 .41 0 . 4 1 1 1 1 1 / 4 L N N 1 4 w a t e r 8 2 1 16 c o n e 4 0 . 5 5 8 . 5 8 2 . 8 1 6 5 . 9 2 8 . 5 5 . 8 1 2 . 2 5 6 . 6 8 1 12 1 / 4 L N N 1 4 w a t e r 125 1 16 c e n t e r 4 0 . 2 44 . 7 4 9 . 5 6 0 . 5 3 6 . 0 6 . 17 1 . 59 2 . 15 SUMMARY OF EXPERIMENTAL RESULTS: Par t IV ( c o n t ) Mean D i a m e t e r s D e t e r m i n e d from E x p e r i m e n t a l Data T e s t No. N o z z l e L i q u i d Used L I q u i d Temp. •c Atom. P res . p s i g Sample L o c a t ' n Mean D i a m e t e r s ( m i c r o n s ) Dev i a t i o n s d i o d i o d i o d i • d geom d s q r t Geo. S q . R t . 1 13 1/4LNN14 water 125 116 cone 8 3 . 4 9 1 . 6 9 8 . 3 113.3 7 2 . 3 8 . 8 5 1 .83 5.04 114 1/4LNN14 water 123 116 cone 7 5 . 0 9 0 . 7 105.8 144 . 0 5 9 . 0 8 . 18 2 .08 8 .03 1 15 1/4LNN26 water 8 B - 50 c e n t e r 16.4 19.4 23 . 1 3 3 . 0 13.9 3 .89 1 .82 1 . 30 1 16 1/4LNN26 water 88 50 cone 4 5 . 9 6 3 . 8 8 5 . 3 152. 1 3 3 . 8 6 .26 2 . 10 6.74 1 17 1/4LNN26 water 1 13 55 cone 4 4 . 0 5 2 . 6 6 2 . 3 8 7 . 6 3 7 . 4 6 . 3 6 1 .74 3 .58 1 18 1/4LNN26 water 1 19 55 c e n t e r 3 0 . 4 3 3 . 7 3 7 . 2 4 5 . 3 2 7 . 7 5 . 3 9 1 .53 1 .45 1 19 1/4LNN26 water 121 55 cone 5 2 . 2 6 4 . 3 7 7 . 0 110.2 4 2 . 2 6 . 8 5 1 .89 5 . 3 5 120 1/4LNN26 water 138 48 c e n t e r 2 9 . 8 3 7 . 1 4 5 . 7 6 9 . 4 2 4 . 9 5 . 2 0 1 .75 2 . 77 12 1 1/4LNN26 water 135 48 c e n t e r 3 0 . 6 3 5 . 6 4 1.4 5 5 . 9 2 6 . 4 5 .32 1 . 7 0 2.21 122 1/4LNN26 water 136 53 cone 7 2 . 5 8 5 . 6 9 6 . 9 124 0 5 7 . 7 8 .08 2 .06 7 . 27 123 1/4LNN26 water 136 53 cone 7 3 . 8 86 . 0 96 . 2 120.5 5 9 . 7 8. 18 2 .02 6 . 89 124 1/4LNN2 water 96 50 c e n t e r 3 8 . 0 4 3 . 3 4 9 . 1 6 3 . 4 3 3 . 6 5 .97 1 .63 3.31 125 1/4LNN2 water 96 50 cone 8 5 . 3 9 3 . 0 100. 3 116.6 7 6 . 6 9 . 0 0 1 .63 4 .21 126 1/4LNN2 water 97 150 c e n t e r 2 5 . 6 2 7 . 9 3 0 . 3 3 5 . 6 2 3 . 6 4 .96 1 . 49 1 .05 127 I/4LNN2 water 98 150 cone 7 1 . 8 7 8 . 6 8 4 . 7 9 8 . 4 6 3 . 8 8 .24 1 .68 3 .82 128 1/4LNN2 water 97 380 c e n t e r 1 3 . 0 13.8 14.8 16 .9 12.3 3 . 5 5 1 . 42 0 . 38 129 1/4LNN2 water 98 380 cone 5 0 . 8 5 7 . 2 6 3 . 3 77 .6 44 . 1 6 . 8 9 1 . 74 3.31 ISO 1/4LNN2 water 98 385 cone 6 2 . 7 7 3 . 7 84 . 7 111.6 51 .8 7 .56 1 . 9 0 5 . 5 0 131 1/4LNN2 56.3XS BL 102 185 cone 6 0 . 3 6 9 . 3 7 8 . 6 101 . 1 52 .0 7 .49 1 . 74 4 . 24 132 1/4LNN2 5 6 . 3 % S BL 108 175 cone 1 13.8 128. 1 143.6 180.3 100.3 10. 34 1 .87 6 79 133 I/4LNN2 5 6 . 3 % S BL 135 170 cone 126.7 140. 7 155.5 189.8 1 14 .0 10.96 1 . 58 6 . 5 2 139 1/4LNN2 5 6 . 3 7 . S BL 121 210 cone 8 4 . 2 9 8 . 7 114.0 152 . 3 7 0 . 8 8 . 8 0 1 . 83 6 . 8 6 140 1/4LNN2 5 6 . 3 % S BL 120 210 cone 6 5 . 1 7 7 . 4 89 . 5 1 19.8 5 3 . 6 7 . 7 0 1 8 9 5 . 9 2 SUMMARY OF EXPERIMENTAL RESULTS: Par t IV ( c o n t ) Mean D i a m e t e r s Dete rmined from E x p e r i m e n t a l Data T e s t No . Nozz1e L i q u i d Used L i q u i d Temp. •C Atom. P r e s . p s i g Sample L o c a t ' n Mean D i a m e t e r s ( m i c r o n s ) Dev ia t ions d i o dt o d i o d , , d geora d s q r t Geo. S q . R t . 14 1 1/4LNN2 56.3%S BL 103 410 cone 9 0 . 6 9 7 . 1 103.8 1 18.6 8 4 . 3 9 . 3 5 1 . 46 3 . 16 142 1/4LNN2 56.354S BL 101 520 cone 8 3 . 5 8 9 . 1 9 5 . 0 108. 1 7 8 . 3 8 . 9 9 1 . 43 2 .65 143 I/4LNN2 55.2%S BL 100 195 cone 105.0 132.2 157.3 2 2 3 . 0 8 0 . 6 9 . 6 0 2 .07 12 .88 144 1/4LNN2 55.2*/.S BL 102 190 cone 166.8 195.9 2 1 5 . 7 261 . 5 121 . 9 12. 11 2 . 5 6 20 . 15 145 1/4LNN2 55.2"/.S BL 100 190 cone 1 17.4 134.0 151.6 193.9 102 .5 10.48 1 . 6 9 7 . 6 9 146 1/4LNN2 55.2XS BL 134 190 cone 128.2 139. 1 150.7 176.8 117.4 11 .09 1 .54 5 . 37 147 1/4LNN2 55.2XS BL 135 200 cone 9 1 . 2 100.6 111.1 135.5 8 2 . 9 9 . 3 3 1 . 55 4 . 25 148 1/4LNN2 55 . 254S BL 133 195 cone 134.3 145.5 156.7 182.0 123. 1 11.34 1 .55 5 . 5 3 149 1/4LNN2 55.2XS BL 1 19 195 cone 144.3 159.6 174.3 2 0 7 . 9 127.7 11.67 1 . 7 0 8 .05 150 1/4LNN2 S5.2XS BL 120 195 cone 133.0 146.2 159.6 190.2 119.6 11 .24 1 .62 6 .64 151 1/4LNN2 55.2%S BL 1 18 200 cone 128.4 142 . 2 156.3 188.2 114.8 11.03 1 .62 6 . 85 155 1/4LNN2 55.2XS BL 120 200 cone 114.7 124.4 134 .4 156.5 105.8 10 .50 1 .49 4 . 6 0 156 1/4LNN2 55.2%S BL 115 200 cone 9 7 . 4 105.4 113.6 131.9 8 9 . 8 9 . 6 7 1 . 5 0 3 .84 TABLE V - 7 SUMMARY OF EXPERIMENTAL RESULTS: Part V Mean D i a m e t e r s of Averaged B lack L iquor T e s t s T e s t No. N o z z l e L i q u i d Used L i q u i d Temp. •C A t o a . P r e s . p s i g Sample L o c a t ' n Mean D i a m e t e r s ( m i c r o n s ) O e v l a t i o n s d . • d t . d> . d . . d geoa d « q r t Geo . Sq Rt BLIOO 1 1/4LNN2 56% S BL too ISO cone 115. 1 136 .0 156.6 2 0 7 . 6 8 5 . 4 10.25 t .87 10.08 B L 1 2 0 ' I/4LNN2 56% S BL 120 200 cone 109.4 I2S .7 141.6 179.3 9 2 . 7 10.06 1.61 8 .30 B L I 3 5 1 I/4LNN2 S6X S BL 135 ISO cone 108. 1 120.4 133.S 164. t 8 6 . 8 10. t t t .61 5 .74 ' Weighted average of t e s t s 143,144.145 ' Weighted average of t e s t s 1 3 9 . 1 4 0 , 1 4 9 . 1 5 0 , 1 5 1 . 1 5 5 ' Weighted average of t e s t s 133 .146.147,148 I M 00 I 

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