Periodic Pressure Fluctuation in a Gaseous Fluidized Bed

Abstract

Pressure responses caused by the periodic oscillation of inlet gas flow were measured in a three-dimensional fluidized bed. Showing that pressure responses could be classified into five groups in terms of both the inlet frequency and the flow rate of gas, operating conditions suitable for pulsed fluidization were defined. The model for pressure fluctuation previously reported was modified by considering the momentum of splashed particles at the top of the bed. The pressure response curves calculated from this model were found to explain well the experimental results obtained under both the externally oscillated inlet-gas flow condition and the free-bubbling condition.
It was found that the fluidized bed was a highly resonant system and that its frequency agreed with the natural frequency of the bed estimated from a linearized model and is controllable by change of bed height and plenum volume.