炭素回转窑内物料停留时间的确定

Calculation of Mean Residence Time of Solids in Carbon Rotary Kilns

在前人建立的等径回转窑内物料料层轴向厚度变化公式基础上,推导出了适合于窑尾扩径和内衬增设翻料装置的变径窑内物料层厚度的计算式;同时利用上述两种窑内料层厚度计算式进一步求出了两种窑内物料停留时间的计算式,计算式中综合考虑了窑内径、窑长、窑头挡料圈高度、窑倾角、窑转速、物料体积流率、物料安息角、物料颗粒粒径等多种因素;为了验证计算公式的正确性,建立了实验装置,进行了冷态实验测试.结果表明,公式计算值与实验测试值比较吻合,误差较小,并且计算中不需要引入修正系数.

Based on the earlier works concerning the formula of the change in the axial depth of a bed in a diameter-invariable rotary kiln,the formula of axial depth of bed in a diameter-variable kiln was deduced to adapt to the diameter enlargement at kiln inlet and the turn-down rigs set on the kiln lining.Then,the formulae of mean residence time of solids in both diameter-invariable and diameter-variable kilns were deduced,where several factors were taken into account,such as the inner diameter,total length,discharge dam height,axis inclination and rotation speed of kiln mass feed rate of solids,and the particle diameter and dynamic angle of repose of solids.Cold-state experiments were carried out on a laboratory rotary kiln to verify the formulae proposed,and the results showed that calculated results of the residence time of solids are basically in agreement with the experimental values,with no correction coefficient required beause of small errors.