Experimental Investigations on Variation in Static Bed Height and Particle Size on Pressure Drop and Bed Expansion Ratio in Three Phase Fluidized Bed

Fluidized beds have got a great application in the industries. Fluidization depends on the effective contact between the phases. So it is very important to understand aspects like type of distributor, particle shape and size, type of fluid etc. for the proper functioning of the fluidized beds. In the present work, hydrodynamics of the fluidized bed with irregular particles was studied. The hydrodynamic behaviour like pressure drop, minimum fluidization velocity and bed expansion ratio of a co-current three-phase fluidized bed have been studied. Experiment was carried out using raschig rings as solid particles, water as liquid and compressed air as gas. Variation of pressure drop and bed expansion ratio with liquid velocity at constant gas velocity and minimum liquid fluidization velocities with gas velocity were investigated. It has been observed that the minimum liquid fluidization velocity, pressure drop decreases with the increase in superficial gas velocity but increases with particle size. Bed expansion ratio increases with increase in the values of both liquid and gas velocities but decreases with diameter of particles and initial static bed height. The results obtained have been compared with other correlations and have been found to agree well.