Effect of Liquid Viscosity and Solid Inventory on Hydrodynamics in a Liquid - solid Circulating Fluidized Bed

A comprehensive hydrodynamic study of a Liquid - Solid Circulating Fluidized Bed (LSCFB) is conducted with changes in viscosity of the fluidizing medium and the inventory height of solids initially fed into the system. An LSCFB of height ۲.۹۵m and riser outer diameter ۰.۱m was chosen for experimentation. The three liquid media systems with varying viscosities that were chosen were water, glycerol ۱۰% (v/v) and glycerol ۲۰% (v/v). Effect of inventory on the hydrodynamics was also studied, by taking initial heights of inventory to be ۱۵cm, ۲۵cm and ۳۵cm. The hydrodynamic studies concentrated on pressure gradients along the axial pressure tapings, axial solid holdup, average solid holdup, solid circulation rate and slip velocity. Uniformity in axial solid holdup and average solid holdup was validated for changes in viscosity and inventory. Solid flux was seen to follow an inverse relationship to holdup. The changes in slip velocity with varying viscosity and inventory were studied, and found to decrease with both variables. The distribution parameter, Co of the drift flux model was found to be in the range of ۰.۹۸۳-۰.۹۹۴, suggesting non-uniformity in radial solid distribution, with higher solid concentration by the walls compared to the core of the column.

کلیدواژه ها:

Fluidization ، Liquid ، solid circulating fluidized bed ، Solid holdup ، Solid circulation rate ، Slip velocity ، Viscosity and inventory