Study on Heat Transfer to Gas-Solids Suspension : Part 1, Influence of Free Turbulence on Heat Transfer

Abstract

This investigation is experimentally carried out on the dependence of heat transfer on the intensity of free turbulence and on the superficial heat capacity of a suspension loaded with glass spherical particles of 55 μm. The experiments are performed using a flat plate, which has a comparatively low temperature surface to make it possible to neglect radiative heat transfer coefficients at a constant surface temperature. A large increase in heat transfer coefficients is shown at loading ratio m<0.8 due to the moving turbulent inducer of particles, when the initial turbulence intensity of main stream is small. In contrast, when the main stream is already in high turbulence, the particles reduce turbulence intensity and in this region the increase in heat transfer is mainly performed by superficial heat capacity of working fluid.