Particle hold-up in two fluidized reactor system with two loopseals

Pressures in a circulation loop under various conditions were measured in a cold mode (a riser of 35 mm I.D. x 5450 mm high and a fluidized reactor of 160 mm I.D. x 1250 mm high) with particles of mean diameter of 78 mum, and bulk, and particle densities of 1.03, and 1.90 g/cm(3), respectively, Soli d circulation rates were measured with a load cell hopper. The particle hol d-ups at various sections were analyzed from differential pressure data. Th e voidage in the riser reactor increases with the increase in gas velocity, even though the solid circulation rate increases with gas velocity. The so lid circulation rate increases to a maximum with gas velocity at the riser, and levels off because the non-mechanical valve adopts the role of solid r ate determining step in the circulation loop of the system. Particle hold-u p in the riser reaction zone increases by using an underflow standpipe loop seal below the fluidized reactor instead of an overflow standpipe loopseal.