Effect of Geometry of the Plenum Chamber on Gas Distribution in a Fluidized Bed

The computational fluid dynamics (CFD) technique was used to simulate a fluidized bed with eight different plenum chambers of different design. The effect of the geometry of the plenum chamber on the velocity profile on the distributor and the pressure drop across the distributor was investigated. The plenums were selected such that the influence of characteristics such as body shape, direction and location of gas entrance, entrance type, and existence and shape of the internal baffle could be studied. The results indicate that the geometry of the body and the existence of the baffle are the most important characteristics that affect the flow uniformity above the distributor. It was shown that the shape of the baffle does not have a remarkable impact on the velocity profile. The direction and location of the gas entrance each has a significant effect on the distribution quality. The downward injection of gas and placement of the gas entrance far enough from the distributor increases the uniformity of flow over the distributor. It was shown that the geometry of the plenum chamber affects the total pressure drop across the distributor. A correction factor was introduced to quantify the effect of the geometry of the plenum on the pressure drop of the perforated plate distributor.