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Void fraction and effective thermal conductivity of binary particulate bed

DSpace at IIT Bombay

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Field Value
 
Title Void fraction and effective thermal conductivity of binary particulate bed
 
Creator MANDAL, D
SATHIYAMOORTHY, D
VINJAMUR, M
 
Subject Void fraction
Particulate bed
Coordination number
Packed fluidized bed
Effective thermal conductivity
Lithium titanate
SPHERICAL-PARTICLES
LITHIUM-TITANATE
MIXTURES
PACKING
DENSITY
SOLIDS
 
Description In many industrial processes, solid particles of different sizes are mixed in different volume or mass fractions for various applications, primarily to reduce void volume or to increase the density of the mixture. A few of these processes include: production of high density ceramics, mortar, concrete, graphite, bricks and carbon blocks. Experiments were carried out with alumina and lithium titanate pebbles (size >= 1 mm) and particles (size < 1 mm) of different sizes and volume fractions in cylindrical and rectangular vessels to study the variation of void fraction with volume fraction of component pebbles and with large pebble to small pebble or pebble to particle size ratio. It was observed that the variation of void fraction with volume fraction of smaller pebbles or particles is 'V-shaped'. Thus there exists a minimum void fraction and two different volume fractions of smaller pebbles or particles which can give same void fraction. The effect of void fraction on the effective thermal conductivity of binary bed of lithium titanate and alumina pebbles and particles of different sizes and volume fractions was investigated. From the experimental results it was found that the binary particulate bed has higher effective thermal conductivity that that of a unary particulate bed. Effective thermal conductivitys of binary particulate bed is the maximum when its void fraction is the minimum. The binary particulate bed with less volume fraction of small particles has higher conductivity than that of the binary bed of higher volume fraction of small particles and having same void fraction. This is due to the fact that with increase in volume fraction of small pebbles or particles, the number of small-to-small and large-to-small pebbles and or particles contact point increases resulting in higher resistance to heat transfers. The experimental details and results are discussed in this paper. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.
 
Publisher ELSEVIER SCIENCE SA
 
Date 2014-10-15T16:51:43Z
2014-10-15T16:51:43Z
2013
 
Type Article
 
Identifier FUSION ENGINEERING AND DESIGN, 88(4)216-225
http://dx.doi.org/10.1016/j.fusengdes.2013.02.033
http://dspace.library.iitb.ac.in/jspui/handle/100/15256
 
Language en