ISSN:
0001-1541
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
This paper concerns a study of radiation as a contributing mechanism in the transfer of heat between discrete solid particles. A theory for transfer in such systems is generalized to include planar-, spherical-, and cylindrical-bed geometries; because of the particulate nature of the system the generalization is given in terms of finite-difference equations. Transfer experiments were performed in a quiescent cylindrical bed with an axial heat source and a cylinderical containing-wall sink. Heat fluxes and radial-temperature profiles were measured. As the experiments were arranged, only modest temprature gradients were established between source and sink, but the ambient sink temperature was taken in steps from 100° to 1,000°C. For a bed of 3.8-mm.-diameter alumina spheres the ratio of heat transferred by radiation to that transferred by conduction was estimated to increase with average bed temperature from the order of 0.1 at 100°C., to 1.2 at 1,000°C. The effects of temperature on bed reflectivity and transmissivity and on apparent boundary-temperature discontinuities are discussed.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aic.690050416
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