Dynamic waves in fluidized beds

Abstract Published results on the velocity of propagation and the change of amplitude of dynamic waves in fluidized beds are reviewed and re-evaluated. A distinction is drawn between pressure waves and solids concentration waves. Over the range of frequencies of interest in fluidized beds, predictions of the velocity of compression waves by pseudo-homogeneous models and by models which treat the two phases separately differ little. Therefore the experimental results are compared against the simpler pseudo-homogeneous models. The behaviour of dynamic waves is inconsistent with models which ignore particle-particle contacts. To distinguish unambiguously between compression and dynamic waves, experiments at elevated pressure are needed. The results are not consistent with pseudo-homogeneous description of compression waves.

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