Heat Transfer from Submerged Body Moving in Granular Bed

Abstract

The heat transfer coefficient between the granular bed and the heating cylinder submerged in it was measured under the conditions that there existed the relative velocity between both ones and that air flowed through the bed. The velocity of through-flow gas was limited to less than the minimum fluidization velocity. The angle between the path-line of particles and the axis of the cylinder was changed. In order to measure the heat transfer coefficient, the heat flux generator was used, which was especially prepared for this measurement. Using this device, the heat transfer coefficient could be easily and quickly obtained.

The heat transfer model was proposed which was based on “the particle heat transfer model” suggested by Schlünder and partly revised by Mollekopf and Martin. Experimental heat transfer coefficients almost coincided with calculated ones. As the results, the effect of through-flow gas on the heat transfer coefficient turned out to be insignificant so long as its velocity was less than the minimum fluidization velocity but the relative velocity between the cylinder and the granular bed was not so small.