Solids Circulation Flux and Gas Bypassing in a Pressurized Spout-fluid Bed with a Draft Tube

摘要

An experimental study on solids circulation flux and gas bypassing of a spout-fluid bed with a draft tube at elevated pressures up to 600 kPa was performed in a 200 mm diameter cylindrical steel column with a 60° conical distributor. Class beads with mean diameter 2.067 mm were used as bed materials to investigate the effect of operating conditions and geometric configuration on the solids circulation flux and the gas distribution between the annulus and the draft tube. A novel technique has been developed to measure the solids fluxes under pressure, and gas (CO_2) traces have been employed to investigate gas bypassing characteristics. The solids circulation flux is greatly enhanced when operating pressure and auxiliary gas flowrate are increased, and it is also strongly influenced by geometric configuration. Two experimental relations are proposed for predicting solids circulation flux enhancement factors.