A hydrodynamic model of loop seal with a fluidized standpipe for a circulating fluidized bed

Abstract

Loop seals are among the most common non-mechanical valves used in circulating fluidized bed systems. In the present work, a fundamental study is conducted of a fluidized loop seal, which consists of a fluidized standpipe, a fluidized supply chamber, and a fluidized recycling chamber. Based on the principles of momentum, mass, and energy conservation, a hydrodynamic model for a loop seal is established, consisting of 13 equations. The effects of operating conditions such as the bottom aeration rate, total solid inventory, and fluidizing gas velocity in the riser on the solids flow rate and the performance of the loop seal are studied by a combination of model analysis and experiments. The experiments are carried out in a circulating fluidized bed with silica gel particles (Geldart group A). The model predictions show good agreement with the experimental data.