荆门重油催化装置外取热器催化剂流动故障原因分析及对策

Causes of Catalyst Flowing Fault in External Heat Exchanger of RFCCU in Jinmen Company

荆门石化1200kt/a重油催化装置反再结构为高低并列、重叠式两段不完全再生型式,再生器配有一台下流式外取热器。2010年6月26日,外取热器出现催化剂流动故障,表现为催化剂在器内基本停止流动,处于死床状态,影响后果是:由于第一再生器过剩热量无法取出,导致再生器超温,装置处理量和掺渣率大幅下降。技术判断认为:外取热器内有部分衬里脱落,堵塞了催化剂流动通道,使催化剂在器内停止流动。为此,制定不停工在线处理技术方案:铺设中压蒸汽反吹线,将外取热器中脱落的衬里吹入第二再生器,打通催化剂流动通道;精细控制第一再生器催化剂进入外取热器的流量,将外取热器进入第二再生器的阀门全开,使催化剂流动更加顺畅;加大外取热器流态化床层流化风流量和催化剂输送立管松动风流量,目的是消除气阻,加快催化剂流动速度。以上方案实施后,外取热器催化剂流动和取热操作逐渐恢复,装置生产转入正常,该处理方案避免了停工处理损失费用共计160万元。

The reactor and regenerator system of Sinopec Jinmen Company＇s 1200kt/a RFCCU is a vertically positioned lapped-type two-stage incomplete regeneration system.The regenerators are equipped with a down flow-type external heat exchanger.On June 26,2010,the external heat exchanger experienced a catalyst flowing problem.The catalyst inside the heat exchanger stopped flowing and the resulting effects include：as the excessive heat in the first regenerator could not be taken out,the regenerators were overheated,leading to a dramatic drop in the processing capacity and residue blending rate of the unit.Technicians judged that lining falling off inside the external heat exchanger had clogged the passage through which the catalyst flowed, thus stopping the flowing of the catalyst.They then worked out an inline solution without the need to stop production：laying a medium-pressure steam back flushing line to blow the lining falling off in the external heat exchanger into the second regenerator,opening the passage for catalyst flowing;accurately controlling the flow rate of catalyst entering the external heat exchanger from the first regenerator and fully opening the valve controlling the entry from the external heat exchanger to the second regenerator to facilitate catalyst flow ;and increasing the rate of flow of fluidized air for the fluidized bed of the external heat exchanger as well as the rate of aeration air for the catalyst-conveying riser,the aim of which is to remove air resistance and quicken the flow of catalyst.After the above measures were taken,the flow of catalyst in the external heat exchanger and heat exchange gradually picked up and operation of the RFCCU resumed to normalcy.Without stopping production for an overhaul,the above solution saved a total of 1.6 million yuan for the company.