Mathematic simulation of heat transfer and operating optimization in alumina rotary kiln
来源期刊：中南大学学报(英文版)2013年第10期
论文作者：YI Zheng-ming(易正明) XIAO Hui(肖慧) SONG Jia-lin(宋佳霖) MA Guang-bai(马光柏) ZHOU Jie-min(周孑民)
文章页码：2775 - 2780
Key words：alumina; rotary kiln; heat transfer; mathematical mode; temperature profile
Abstract: Based on the analysis of material motion in the axial direction, heat transfer and mass transport processes in a rotary kiln, and combining with pulverized coal combustion, material pyrogenation, cooling of furnace wall finally, and heat transfer and mass transport equations, the combined heat transfer mathematical model for alumina rotary kiln was built up. According to the in-site real operation parameters, the heat transfer mathematical model was solved numerically for an alumina rotary kiln to predict the temperature profiles of gas and material in the axial direction. The results show that as the excess air coefficient reduces from 1.38 to 1.20, the temperature of the sintering zone increases and the length decreases. However, as the excess air coefficient reduces from 1.20 to 1.10, the temperature of the sintering zone decreases and the length increases. When the mixed coal amount at the end of kiln is reduced from 68.6 kg/t to 62.0 kg/t and the burned coal amount at the head of kiln correspondingly increases from 155.3 kg/t to 161.9 kg/t, the sintering zone temperature increases and the length reduces. The suitable excess air coefficient and mixed coal amount at the end of kiln are recommended for the rotary kiln operation optimization.
YI Zheng-ming(易正明)1, XIAO Hui(肖慧)1, SONG Jia-lin(宋佳霖)1, MA Guang-bai(马光柏)2, ZHOU Jie-min(周孑民)2
(1. Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education (Wuhan University of Science and Technology), Wuhan 430081, China;
2. School of Energy Science and Engineering, Central South University, Changsha 410083, China)
Abstract:Based on the analysis of material motion in the axial direction, heat transfer and mass transport processes in a rotary kiln, and combining with pulverized coal combustion, material pyrogenation, cooling of furnace wall finally, and heat transfer and mass transport equations, the combined heat transfer mathematical model for alumina rotary kiln was built up. According to the in-site real operation parameters, the heat transfer mathematical model was solved numerically for an alumina rotary kiln to predict the temperature profiles of gas and material in the axial direction. The results show that as the excess air coefficient reduces from 1.38 to 1.20, the temperature of the sintering zone increases and the length decreases. However, as the excess air coefficient reduces from 1.20 to 1.10, the temperature of the sintering zone decreases and the length increases. When the mixed coal amount at the end of kiln is reduced from 68.6 kg/t to 62.0 kg/t and the burned coal amount at the head of kiln correspondingly increases from 155.3 kg/t to 161.9 kg/t, the sintering zone temperature increases and the length reduces. The suitable excess air coefficient and mixed coal amount at the end of kiln are recommended for the rotary kiln operation optimization.
Key words:alumina; rotary kiln; heat transfer; mathematical mode; temperature profile
