Dynamics of liquid‐solid fluidized bed expansion

Abstract

Abstract The dynamic response of height in liquid‐solid fluidized beds to a change in fluidizing valocity was considered. A linearized model was developed such that the time constant for the system could be estimated with the parameters characterizing the system. Spherical particles, with sizes ranging from 6 to 7 to 70 to 80 mesh and densities ranging from 1.08 g./cc. to 2.5 g./cc., were fluidized by water in a 2‐in. diameter glass column. The experimental response to step and rectangular pulse inputs in fluidizing velocity were measured and frequency response data were also obtained. Agreement between the experimental data and the model was quite reasonable in view of the known nonlinearity of fluidization systems. These results show that for control purposes the system behaves as a first order time constant process.