烧成系统旁路放风装置的过程研究与开发设计

为解决原燃料中钾、钠、氯、硫等元素对新型干法窑生产过程造成影响,使系统运行稳定,以保证产品质量.采用窑尾旁路放风装置是目前解决高含量钾、钠、氯问题的有效途径.采用CFD数值模拟技术,利用在开源代码OpenFOAM基础上的开发模型,通过对折流式放风装置的参数化研究,以及与直流式混合室的对比,对两种型式的放风装置进行综合分析.研究结果表明:(1)折流式放风装置,采用低入口风速有利于提高冷却效果;其出口面积的大小影响装置的阻力,据此可通过出口尺寸确定来调整系统平衡;但在出口处会有部分高温区域与器壁相接触,可能造成结皮堵塞.(2)细长型蜗壳折流式混合室的冷却风混合效果不如短蜗壳好. (3)直流式放风装置,在出口处克服了折流式的缺陷,但其进口处也会存在部分高温区域与器壁相接触现象,且其混合强度较弱,需较长的混合距离.

Research and development of the bypass device in burning system

To avoid the bad effect caused by K, Na, S etc that come from raw material and fuel on new dry process cement production, to ensure the system stable running and to guarantee the product, it is an effective measure to use a bypass device at the kiln end at present. By CFD Numerical Simulation Technology and the development model based on the Open source code of OpenFOAM, studied the parameters of the baffled bypass device and compared it with the straight-flow bypass device, finally, synthetically analysed the two kinds of bypass device. The results show as follows, first, for the baffled bypass device, its low inlet air speed is a benefit for improving the cooling effect, and the surface of its outlet may affect the resistance of the system, according to which we can adjust the balance of the whole system by the outlet size, but a part of high temperature zone meets with the device wall at the outlet, which may cause coating and blocking; second, the mixing effect of the cooling air in the long snai-shell baffled mixing chamber is not so good as that of the short snai-shell; finally, for the straight-flow bypass device, although it is better than the baffled bypass device for its outlet, there still existing meeting zone, and the mixing is so weak that it need a long mixing distance.