[{"key":"dc.contributor.author","value":"Cao, Feng","language":null},{"key":"dc.date.accessioned","value":"2009-12-03T23:10:01Z","language":null},{"key":"dc.date.available","value":"2009-12-03T23:10:01Z","language":null},{"key":"dc.date.issued","value":"2005","language":null},{"key":"dc.identifier.uri","value":"http:\/\/hdl.handle.net\/2429\/16313","language":null},{"key":"dc.description.abstract","value":"Heat transfer is fundamental to pyrometallurgy processing and the viability of new or existing\r\nprocesses often hinges on achieving high rates of heat transfer into the material being processed.\r\nSlags are a feature of extractive and refining processes and heat transfer through liquid slag is an\r\nimportant part of many operations, for example utilizing energy from port-combination in the\r\nEAF for scrap melting. However, relatively little work has been directed at characterizing heat\r\ntransfer through non-stagnant slag layers. Heat transfer through the slag includes conduction,\r\nradiation and, with stirring, advection due to flow within the slag. The combined effect of all\r\nthree mechanisms is convection but it is often more convenient to combine all three as an\r\neffective thermal conductivity.\r\n\r\nA review of methods currently employed to measure the conductivity of stagnant oxide melts,\r\nwhich involve numerical solution of the transient conduction problem for interpretation of the\r\ndata, did not indicate that any method was readily adaptable to stirred systems nor were they\r\nbroadly applicable to a wider range of materials such as liquid metals or granular solids. Based\r\non these factors the objectives of the work were to develop a broadly applicable steady-state\r\nmethod for directly measuring the effective thermal conductivity of a variety of materials\r\nranging from stationary granular solids to liquid oxides and metals (with or without stirring) for\r\ntemperatures covering the spectrum encountered in extractive metallurgy, and to use the\r\ntechnique to determine the extent to which the effective thermal conductivity of liquid oxides\r\nmight be increased by flow-induced stirring. The methodology covers a range of issues related to\r\nthe design of the apparatus, interpretation of the raw data and general validation of the technique. \r\n\r\nFor stagnant systems the technique was validated at low temperature against existing\r\nconductivity data for both water and silicon oil and good agreement was obtained. For\r\nintermediate temperatures trials were also carried out using several granular materials at\r\ntemperatures up to about 800\u00b0C and results were shown to be within the range indicated by some\r\ncommon models for predicting conductivity of packed beds. As expected, the measured\r\nconductivity of packed beds increases with temperature due to the radiative contribution to heat\r\ntransfer. For the limited range of sites tested no clear link between particle site and conductivity\r\nwas observed. High temperature validation was obtained against existing data for oxide melts\r\n(40%CaO - 40%SiO\u2082 - 20%Al\u2082O\u2083 ) and again good agreement was shown.\r\n\r\nFor non-stagnant systems, of the liquids tested, water, silicon oil and oxide melts, only the\r\nformer showed the rotation-induced flow to have any significant effect on effective thermal\r\nconductivity. This was explained by the calculated peripheral Reynolds and Taylor numbers for\r\nthe systems that indicted laminar flow for oil and oxide melts and turbulent flow for water. For\r\nwater with turbulent flow and at shear rates up to 0.55 sec\u207b\u00b9, the effective conductivity increased\r\nby a factor up to ~ 2.7 which is well short of the order of magnitude increase deemed desirable\r\nfor heat transfer through the slag layer in the rotary scrap-melting furnace. For silicon oil with\r\npaddle mixers and at shear rates up to 0.55 sec\u207b\u00b9, the effective conductivity showed only a small\r\nincrease.","language":"en"},{"key":"dc.format.extent","value":"5955161 bytes","language":null},{"key":"dc.format.mimetype","value":"application\/pdf","language":null},{"key":"dc.language.iso","value":"eng","language":"en"},{"key":"dc.publisher","value":"University of British Columbia","language":null},{"key":"dc.rights","value":"For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https:\/\/open.library.ubc.ca\/terms_of_use.","language":null},{"key":"dc.title","value":"Measurements of the effective thermal conductivities of granular solids and oxide melts under shear strain by a new technique","language":"en"},{"key":"dc.type","value":"Text","language":null},{"key":"dc.degree.name","value":"Master of Applied Science - MASc","language":"en"},{"key":"dc.degree.discipline","value":"Materials Engineering","language":"en"},{"key":"dc.degree.grantor","value":"University of British Columbia","language":null},{"key":"dc.date.graduation","value":"2005-05","language":"en"},{"key":"dc.type.text","value":"Thesis\/Dissertation","language":"en"},{"key":"dc.description.affiliation","value":"Applied Science, Faculty of","language":null},{"key":"dc.description.affiliation","value":"Materials Engineering, Department of","language":null},{"key":"dc.degree.campus","value":"UBCV","language":"en"},{"key":"dc.description.scholarlevel","value":"Graduate","language":"en"}]