PSA装置程控阀内漏判断与解决措施

Judgment and solution of internal leakage of program-controlled valve in PSA unit

某炼化公司13 dam^3/h氢气提纯装置的尾气中氢体积分数高达45%,经判断为部分程控阀修复后仍内漏,对其进行更换后,尾气中氢体积分数降至35%,变压吸附(PSA)氢气回收率提升至82.5%。阀门内漏原因主要有密封圈老化、主密封圈及阀体密封面磨损、阀杆与阀板连接的方键与键槽出现松动导致锥销断裂、阀板偏移以及阀门阀杆与执行器连接的方键与键槽有间隙、齿轮与齿条有松动间隙。密封圈老化、主密封圈及阀体密封面磨损、阀杆与阀板连接的方键与键槽出现松动导致锥销断裂、阀板偏移等问题可取返厂检修更换密封圈及对密封面进行研磨、切削,实现对内漏阀门的修复。但是,对于齿轮磨损间隙、阀座磨损缺陷问题,靠修复已难以彻底解决。

The hydrogen content in the tail gas of 13 dam 3/h hydrogen purification unit in a refining and chemical company is as high as 45%.It is judged that there was still internal leakage in the program-controlled valve after partial repair,and the program-controlled valve that was still internally leaking after repair is replaced.The hydrogen content in the tail gas is reduced to 35%,and the hydrogen recovery rate of PSA is increased to 82.5%.Combined with the disassembly and inspection of the program-controlled valve during overhaul,the main causes of valve internal leakage are aging of sealing ring,wear of main sealing ring and sealing surface of valve body,loosening of square key and keyway between valve stem and valve plate leading to cone pin fracture,valve plate offset,clearance between square key and keyway between valve stem and actuator,and loose clearance between gear and rack.Aging of sealing ring,wear of main sealing ring and valve body sealing surface,loosening of square key and keyway between valve stem and valve plate,resulting in cone pin fracture and valve plate offset,can be taken back to the factory for repair and replacement of sealing ring,grinding and cutting of sealing surface,so as to realize the repair of internal leakage valve.However,for the problem of gear wear clearance and valve seat wear defect,it is difficult to completely solve by repairing.