PARTICLE CIRCULATION AND LIQUID BYPASSING IN 3-PHASE DRAFT TUBED SPOUTED BEDS

The design of any fluid-solid contacting system is based on a knowledge of certain intrinsic parameters and their functional dependence on extrinsic or easily measurable parameters such as system geometry, flow rates, etc. For Three Phase Draft-Tubed Spouted Bed systems(TPDS), the important intrinsic design parameters are the particle circulation and the liquid distribution between the draft tube and the annulus. The extrinsic parameters are liquid and gas flow rates, solid loading, particle size, inlet size and draft tube size and spacing. In this paper a semi-empirical model is developed which relates the intrinsic design parameters to extrinsic variables at a constant draft tube size. The model is based on the earlier work of Grbavcic et al. (1991a,b) who used a variational drag in transport systems and Matthew's (Ph.D thesis, RPI, Troy NY) work on pressure profiles in draft tubed spouted beds.