Prediction of particle circulation rate in an internally circulating fluidized bed with a central draft tube

Abstract

Controlling the internal particle circulation rate quantitatively is of great importance to the operation of the internally circulating fluidized bed with a central draft tube used in the biomass gasification field. In this work, the effects of the operating parameters on the internal particle circulation rate were investigated on a laboratory experimental apparatus. The results indicated that the internal particle circulation rate increased with the increasing air velocity in the central draft tube, and gently increased with the air velocity in the annular bubbling bed. The internal particle circulation rate increased with the increasing initial static bed height in the annular bubbling bed and decreased with the increasing particle size. The correlation formula was obtained through the regression of experimental data. Furthermore, a dynamic prediction model was established based on the theory of fluid mechanics, and the matching degree between the predicted values and experimental data was larger than 80%.