煅后焦颗粒在余热回收换热器内流动特性试验研究

为了提高煅后焦余热回收效率,改进余热回收换热器设计,研究了煅后焦余热回收换热器内颗粒的流动特性.搭建等比例缩小的以有机玻璃为材料的余热回收换热器试验台,进行可视化试验,并且提出了一种流动均匀性的评价方法.试验采用粒子示踪法,定时进行数据采集,研究了煅后焦颗粒在换热器内的流型变化情况、颗粒流动轨迹和流经内换热器的绕流情况,以及颗粒粒径、流动速度对流动均匀性的影响,并拟合了流动均匀性随粒径变化的公式.试验结果表明:煅后焦在换热器内流动为整体流;物料流经内换热器时沿上集箱绕流,流动过程中无堵塞现象;在试验范围内,随着煅后焦粒径增大,流动均匀性变差;煅后焦在换热器内的流动速度对流动均匀性影响较小.

Experimental Study on the Flow Characteristics of Calcined Petroleum Coke Particles in a Heat Exchanger

In order to improve the efficiency of calcined petroleum coke(CPC) heat recovery and the design of heat exchanger,the flow situation of CPC particles in a heat exchanger was studied.The experimental bench was scaled down and made of plexiglass,so that visual experiments can be carried out.An evaluation method for the flow uniformity was presented.By using the methods of particle tracing and timing data acquisition,the variation of the flow pattern of particles in the heat exchanger,the trajectory of the particle flow and the flow around the inner heat exchanger were observed.The influences of the particle size and flow rate on the flow uniformity were also discussed.In addition,the formula for the flow uniformity along with the change of the particle size was fitted.The results show that the flow pattern of CPC presents itself as a whole flow in the heat exchanger,and particles will flow around the header when the material flows through the internal heat exchanger and no clogging appears in the flow process.It''s also found that as the CPC particle size increases,the flow uniformity is poor within the experimental range,and the flow rate of the CPC in the heat exchanger has little effect on the flow pattern and flow uniformity.