催化裂化装置旋风分离器的锥体器壁磨损穿孔分析

Analysis of Wear Holes on Cone Wall of Cyclone Separator in FCC Unit

某1.0 Mt/a催化裂化装置在运行过程中,再生器旋风分离器的锥体发生了器壁磨损穿孔损坏。旋风分离器器壁磨损穿孔后导致分离效率下降,出现了比较严重的催化剂跑损故障。为此,依据气固两相流的磨损模型和气固旋流流场特点分析了磨损穿孔问题发生的过程。催化剂在旋风分离器内部的离心力和重力的作用下聚集在器壁表面形成了下行的螺旋灰环。当螺旋灰环运动到锥体段时,灰环的加速旋转流动使灰环螺旋角减小,在器壁表面形成一个悬浮的旋转灰环,同时灰环的颗粒浓度也增大,对器壁的正压力增大,导致对器壁摩擦作用增强,最后造成锥体器壁的磨损穿孔。

The cyclone separator in the regenerator of a 1.0 Mt/a fluid catalytic cracking unit had the wear holes on the wall during operation,as a result,the separation efficiency of cyclone separator decreased,and a serious catalyst loss occurred.This paper analyszes the process of wear hole based on the wear model of gas-solid two-phase flow and the characteristics of gas-solid swirling flow field.Under the action of centrifugal force and gravity inside the cyclone separator,the catalyst gathers on the surface of the cyclone wall to form a downward spiral ash ring.When the spiral ash ring moves to the cone section,the swirling flow of the ash ring is accelerated and the spiral angle of the ash ring is reduced,forming a suspended rotary ash ring on the surface of the cone wall.At the same time,the particle concentration of the ash ring also increases,and the normal pressure on the cone wall is raised,resulting in enhanced friction and finally causing wear hole on the cone wall.