Heat transfer from a plane sufrace to liquids and to liquids-solid fluidised beds

Abstract

Heat transfer coefficients have been measured for transfer between a small immersed electrically heated surface and both liquids and liquid-solid fluidised beds. Fluid viscosity, and hence Prandtl number, has been varied approximately 600 fold. Experimental results for liquids have been expressed in terms of Nusselt, Reynolds and Prandtl numbers and for the fluidised systems in terms of Stanton number, particle Reynolds number for free falling conditions, and bed voidage. Maxima in the heat transfer coefficient-voidage relations are satisfactorily predicted.