Parameters Optimization of Four-air Channel Pulverized Coal Burner in Rotary Kiln

摘要

This paper presents a 3-dimentional numerical study on the effects of various operational and structural parameters of a four-air channel pulverized coal burner on flame feature and temperature profile in an alumina clinker rotary kiln with CFX software, which provides reference for optimal design and operation of the multi-jet coal burner. A thermal measurement was conducted on an alumina rotary kiln (4.5m in diameter, 90m in length) with four-air channel coal burner to determine the boundary conditions. The calculation result shows that ratio of swirl air to axial air is the key factor influencing the flame shape and thermal distribution in kiln, and the opening ratio can be regulated from 40/100 to 65/80 according to the actual work conditions. For large kiln, the angle of swirl jet can be 45° . The appropriate excess air coefficient in sintering zone is 1.40. For anthracite, coal size should be limited within 40 μm.