(223f) Bed Density in a Grating Internals Fluidized Bed Stripper
As is typical for two-phase countercurrent flow unit operations, flooding can be an issue with strippers. Flooding can occur at a given gas velocity if the solids flow is too high or at a given solids flow rate if the gas velocity is too high. Installing internals reduces the risk of flooding because they promote cross-current contacting between gas bubbles and the catalyst. Therefore, as has been previously observed, usage of internals increases not only the stripping efficiency but also the flow through capacity of the stripper.
Test were conducted in a 0.9-m-diameter, 7.5 m tall column with a 3.7 m height baffled with horizontal grating trays, spaced 0.6 m apart. Pressure drops were measured across the baffled height to estimate the stripper bed density. Tests were conducted using equilibrium fluid catalytic cracking (FCC) catalyst at a superficial gas velocity of 0.3 m/s at solids fluxes of up to 150 kg/s-m2. In this presentation, we will report stripper density variation with solids flux.