INTERPHASE MASS TRANSFER FROM SPOUTS CONNECTING THE DISTRIBUTOR PLATE TO FORMING BUBBLES IN FLUIDIZED BEDS

Axial and radial concentration profiles of two tracer gases, methane and naphthalene, have been measured above orifices feeding gas into the base of fluidized beds of diameter 152 mm. The experiments were carried out under hydrodynamic conditions that led to short spouts connecting a central orifice to forming bubbles. Under these conditions mass transfer is shown to be primarily due to convective outflow from the spouts into the dense phase. The mass transfer is predicted with reasonable success by a convective model which uses pressure profiles to help fix hydrodynamic variables and assumes a series of well mixed annular cells in the dense phase.