催化裂化再生器树枝状气体分布器射流作用区的床层压力脉动特性

在催化裂化装置中再生器底部通常设置有树枝状气体分布器，通过分布器上的喷嘴分布气体。分布器射流区的压力信号可以很好地反应分布器的流场特性，为减小磨损进行结构改进提供理论依据。为此，在二维床实验装置上针对分布器射流区压力分布及压力脉动进行了实验研究，结果表明：分支管间床层压力沿床层轴向高度逐渐减小，随喷射角度增大而减小，随喷嘴出口气速和静床高度增大而增大，由测点以上的物料量决定，可用来判断不同操作工况；当喷射角度为0°和22.5°时，分支管间处于密相区，压力脉动先增后减，对应着气泡的产生、聚并和破碎的规律；当喷射角度为45.0°和67.5°时，分支管间由射流形成稀相区，压力脉动由气流湍流度决定，高于密相区，随喷嘴出口气速和静床高度增大而增大，可为减小分支管外部磨损提供依据；影响喷嘴射流压力脉动的因素为相邻喷嘴射流冲击和颗粒的作用，喷射角度为22.5°时的射流压力脉动存在临界气速，取决于是否受到相邻射流的冲击，可以为喷嘴射流稳定性及工业上减小分布器的内部和外部冲蚀磨损提供理论依据。

BED PRESSURE FLUCTUATION CHARACTERISTICS IN JET AREA OF PIPE GRID GAS DISTRIBUTOR IN FCC REGENERATOR

In the catalytic cracking unit, the bottom of the regenerator is equipped with a pipe grid gas distributor. The gas is distributed into the regenerator bed through the nozzles on the distributor. The pressure signals in the jet area can react well to the flow characteristics of the distributor, which provide a theoretical basis for the structural improvement to reduce wear. The experimental study on the distribution of pressure and pressure fluctuation in jet area was conducted in a two-dimensional bed experimental device. The experimental results showed that the pressure of bed between the branch pipes decreases along the axial height of the bed, decreases with the increase of the jet angle, increases with the increase of the nozzle gas velocity, and the static bed height, bed pressure is determined by the amount of particles above the measuring point, which could judge different operating conditions; When the jet angle is 0 ° and 22.5 °, the pressure fluctuation between branch pipes first increases and then decreases, which corresponds to the law of bubble generating, convergenting and crushing; when the jet angle is 45.0 ° and 67.5 °, the lean phase space is formed by the jet between the two branches, the pressure fluctuation is determined by the turbulence degree of the jet and higher than that of the dense phase, increases with the gas velocity and the height of the static bed, providing a basis for reducing the external wear of branch pipes. The co-work of adjacent nozzle jet impact and particles are the factor to influence the nozzle jet pressure fluctuation. Jet pressure fluctuation at a jet angle of 22.5 ° has a critical gas velocity depending on whether it is impacted by an adjacent jet, providing a basis for the stability of the jet and reducing internal and external erosion wear of gas distributor.