Fluidization

Fluidized Beds are typically used as gas-solids contactors and have many uses in the chemical industries. Fluidized beds might be used as contactors in catalytic reactors, for drying, mixing, heat transfer, coating or surface treatment, or in adsorption-desorption applications. The fluidized bed consists of a layer or bed of solid particles with a system for distributing gas up through the solids. Initially, the gas passes up through the bed of solids at low velocity. As the velocity is increased the bed expands. The forces exerted by the gas on the solid particles balance with the downward gravitational forces of the solid particles and the fluidization point is achieved. While the gas velocity is increasing the pressure drop across the bed increases to a maximum before dropping slightly at the fluidization point.

In this experiment, air is passed through a bed of uniformly sized particles to develop a graph of pressure drop versus velocity. The results are compared to theoretical values.