两再生器同轴布置FCC装置再生器料位控制难的原因

中国石油化工股份有限公司武汉分公司第二套催化裂化装置的两个再生器为同轴重叠式布置,第一再生器(一再)在第二再生器(二再)之上,一再、二再间用凸状分布板隔开.催化剂再生系统自1995年开工以来多次出现流化失常现象,一再料位难以控制,严重影响装置正常生产,通过对一再密相床层温度的分析,初步认为是由于一再流化床风速分布不均,一再至二再的半再斜管入口风速过高,催化剂难以流入半再斜管所致.2005年装置改造时将一再主风分布环改为双环并在半再斜管入口处增设溢流斗后,该问题基本得到解决.

DIFFICULTY IN CONTROL OF CATALYST LEVEL IN FCC REGENERATOR AND COUNTERMEASURES

The No. 2 FCC unit in SINOPEC Wuhan Company is of two-stage regenerator design with 1ststage regenerator on the top of the 2 nd-stage, and two regenerators are separated by distributor. The regenerator has experienced a number of mal-fluidizations since 1995, which made it difficult to control the catalyst level in the 1 st-stage regenerator and affected the normal operation of the FCC unit. The analysis of the temperature of 1 st-stage regenerator dense-phase bed preliminarily concluded that the mal-fluidization of the catalyst was caused by the mal-distribution of air velocity in the 1 st-state fluidized bed and excessive air velocity at the inlet of semi-regenerated catalyst line to the 2nd-stage regenerator, which made it difficult for the catalyst to flow to the semi-regenerated catalyst line. The problem was solved when the air distributor was replaced with double-ring distributor and a new overflow hopper was installed in the overhaul in 2005.