期刊名称：International Journal of Innovative Research in Science, Engineering and Technology
印刷版ISSN：2347-6710
电子版ISSN：2319-8753
出版年度：2013
卷号：2
期号：4
页码：1106
出版社：S&S Publications
摘要：The internal convection currents generated during the cooling process affect convective heat transfercoefficient from the surface of the container, these convection currents may increase the effective value of the surfacefilm conductance (h). Therefore, in such situation the Nu-Re correlations, which are generally used to predict h-values,may not yield realistic results. In the present work, this effect has been investigated by using the empirical correlationdeveloped through Temperature-Time measurements at the centre of liquid food containers during cooling .The mainconcern of the present work is about considering the heat transfer behaviour for liquid foods for which a cylindricalshape container of brass metal have taken, in this work the transient Time-Temperature relation is utilized to calculatethe value of convection heat transfer coefficient (h) for each measured temperature at the centre of the cylinder (ro=0).Then after plotting the graph between „h‟ and „T‟ an expression between h and T is obtained, which is fed back in theprogramme developed with the help of finite difference method by which Time-Temperature variation is obtained.Experimental procedure was used to determine surface film conductance of cylindrical Apple and Orange juicecontainer, calculated temperatures have been compared with the experimental results when the measured surface filmconductance were used to solve the transient heat conduction equation in cylindrical coordinates. A consistentlyexcellent agreement was observed.
关键词：Convection currents; Convective heat transfer coefficient; surface film conductance; liquid foods
