The radial solids fraction profiles in the entrance of a 140mm id.Downer was studied by means of a duel─beam optical fiber solids density sensor.The effects of entrance structure

solids circulating rate

gas velocity on radial solids fraction profiles were studied.The radial solids fraction profile can be divided into two regions:the distributor effect region and turbulence control region.The entrance structure has a large influence on the solids fraction profile.A phosphorescent tracer method has been used to determine solids residence time distribution in the entrance of downer.The entrance effect reduces axial solids backmixing and enlarges radial solids mixing.The effects of entrance structure

solids circulating rate

gas velocity and solids fraction on axial and radial solids mixing were studied.The entrance structure has a large influence on the radial solids mixing near the entrance region.