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Heat transfer to clouds of particles
Author(s) -
Themelis N. J.,
Gauvin W. H.
Publication year - 1963
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450410103
Subject(s) - heat transfer , reynolds number , convection , particle (ecology) , materials science , thermodynamics , convective heat transfer , mechanics , hydrogen , chemistry , analytical chemistry (journal) , turbulence , physics , chromatography , organic chemistry , geology , oceanography
An analysis was made of the rate of heat transfer by convection, radiation, and chemical reaction to a dispersion of particles in a non‐absorbing gas. The gas‐solids suspension was subjected to co‐gravitational flow at low Reynolds Numbers (50–500) through a cylindrical reactor, the wall of which was maintained at a uniform temperature (400–900°C). The rate of heat transfer by convection from the wall to the gas was determined experimentally. The differential equations were solved on an IBM‐650 digital computer, for the reduction of iron oxide particles (40 to 100 microns) by hydrogen. The program output recorded the particle residence time and corresponding values of gas and particle temperatures, length of reactor travelled, percent reduction, and individual rates of heat transfer to the particle by convection, radiation and chemical reaction. Experimental measurements in an electrically‐heated, 4.4‐in. i.d. × 8.5 ft. long stainless steel reactor verified the calculated prediction that the particle temperature should at all time be nearly equal to that of the gas.