HEAT-TRANSFER IN GAS-FLUIDIZED BEDS .2. DEPENDENCE OF HEAT-TRANSFER ON GAS VELOCITY

In Part 1 of this paper, the dependence of heat transfer between heating or cooling surfaces and bubbling fluidized beds on systems properties was investigated. This investigation resulted in six correlations, which define the respective maximum heat transfers. The present paper shows that heat transfer depends on superficial gas velocity in terms of a nondimensional excess gas velocity, which defines the ratio of effective heat conductivity by particle mixing to heat conduction in the fluidizing agent. Simple procedures for reliable prediction of heat transfer in bubbling fluidized beds are presented.