Void Characteristics in Turbulent Fluidized Beds

Abstract

Void properties(size,rising velocity)in the turbulent flow regime have been determined in a 0.1m-I.D*3.0 m high Plexiglas column of glass beads(dp=0.326 mm)by using an optical fiber probe system. The bubbles size increase with an increase in gas velocity in the slugging flow regime but it sharply decreases in the turbulent flow regime. The mean amplitude of pressure fluctuations is limearly related to the bubble or void size in the bed. The void rising velocity is almost constant in the turbulent flow regime. Uniform condition of the bed structure in the turbulent flow regime can be determined from the void distribution codfficient in the bed. In addition, the bed condition in the turbulent flow regime has been evaluated from the variations of the void velocity coefficient and the propulsive power of a rising void with gas velocity.