| Abstract: | Very shallow gas-fluidized beds, typically under 0.1 column diameters in settled depth, exhibit coherent particle oscillations, also manifested by regular pulsations in bed height. This phenomenon has been studied experimentally and correlations have been developed for the oscillation frequency and the maximum bed height. The results give qualified support for the theories of Hiby and Verloop and Heertjes, but needs for improvement in the theoretical approaches and for more experiments are also evident. In particular the effects of column diameter, distributor resistance, and plenum volume need systematic study in order to answer questions raised by our work, a theoretical suggestion by Davidson, and results of Baird and Klein for an adjacent operating regime. |
