Critical Bed Height for Solid Circulation in a Compartmented Gas-Fluidized Bed

Abstract

The influence of design and operating parameters on minimum upstream bed height required for steady solid circulation across a compartmented gas-fluidized bed has been studied. The partition plate in the compartmented bed is fitted with two pairs of V-valve and riser with orifices in them. Silica sand of three different sizes, viz., 490 μm, 325 μm and 250 μm, has been used and the range of the aeration rate tested covers 1–3Umf through the bed, 5–60Umf through the V-valve and 0–60Umf through the riser. A model incorporating pressure balance across the circulation loop has been developed to analyze the experimental findings. Studies show the existence of a unique critical bed height for a given set of fluidization velocities through the bed, V-valve, riser and the size of the solids.