关键词: 石油焦, 回转窑, 传热过程, 传质过程, 数学模型

Abstract: Based on the analysis of material motion in the axial direction, heat transfer and mass transport process in a rotary kiln, and comprehensive consideration of the effects of physical change and chemical reaction in the rotary kiln on the heat transfer process, the mathematic model of heat transfer for petroleum coke calcining rotary kiln was built up. The heat transfer mathematic model was solved numerically for an industrial kiln reported in the literature to predict the temperature profiles of the solid bed, the gas phase and the kiln internal wall in the axial direction. The results show that the high temperature region in the kiln is in the zone that volatile matter massively burns. The injection of tertiary air causes obvious drop of gas temperature, but there is no obvious change of solid temperature. In the heat exchange process among material, gas and inwall, the heat convection between the material and the inwall covered with material, and the heat radiation between the gas phase and the surface of solid bed are the principal heat transfer mechanism. The predicted results are in good agreement with the measured data. This model can be used to guide the optimum design and economic operation of petroleum coke calcining rotary kilns.

Key words: petroleum coke, rotary kiln, heat transfer process, mass transfer process, mathematic model