一种新型气固分离器气相流场实验研究

Experimental Research of the Flow Field in a Novel Gas-Solids Separator

针对后置烧焦管式组合催化裂化再生工艺的要求设计了一种用于烧焦管出口的新型气固分离器。为进一步优化分离器结构，弄清分离机理，采用五孔探针在入口气速为10-22m·s^-1的实验范围内对分离器内部气体流场进行了测试，得出了该分离器内气相流场的整体特性——气流绕中心管旋转，以切向气速为主，愈靠近中心管切向气速越大，径向和轴向气速均较小。同时分析了入口气速对流场的影响规律。在此基础上，给出了计算无因次切向气速的经验公式，公式预测结果与实验值吻合较好。依实验数据计算出了通过两条窄缝及经下方空间返回气量占进入第一条窄缝前气量的比例分别为31％、41％和28％，上述比例不随入口气速变化，说明分离器操作稳定。根据气相流场实验数据结果，指出了进一步结构优选的方向。

A new type of catalyst regeneration technique combining the post coke-burning riser and the conventional turbulent bed regenerator was proposed previously. One of distinct features of the technique is the arrangement of the gas-solid separator which is located at the outlet of the riser, where it may bring forth some advantages such as the simple structure, the higher separation efficiency, the lower pressure drop, and flexible operation. To meet these requirements, a novel gas-solid separator incorporating the inertial and the centrifugal separation mechanism was figured out. Based on the previous study on the structural optimization and the performance investigation, the flow field of the proposed separator was studied by using five-hole probe under the operating condition of the inlet gas velocity 10-22 m·s^-1. The main characteristic of this type separator is that gas flowing around the central pipe is mainly along tangential direction, the closer to the central pipe the higher the velocity is. Based on the experimental results, the structure advantages and disadvantages were discussed. At the same time, the proportions of gas flux passing through the slots and under central pipe space were calculated, respectively. Furthermore, the formula for predicting the tangential velocity distribution was given.