裂解气压缩机机械密封失效的原因分析.doc

裂解气压缩机机械密封失效的原因分析
摘要: 阐述了机械密封零部件损坏的现象,从原理上分析了密封油泄漏的原因和机械密封元件损坏的原因。
关键词: 离心式压缩机; 机械密封; 泄漏;喘振
中图分类号 TH452 文献标识码: B
Reason Analysis of the Invalid Mechanical Seal in Cracked pressor
Abstract: This paper has specified the damage phenomenon of mechanical ponents and theoretically analyzed the reasons of seal oil leaking and damaged mechanical ponents.
Key words: pressor; mechanical seal; leaking; surge
1 机械密封简介和失效判断
1 introduction of mechanical seal and failure judgement
兰州石化公司乙烯联合车间烯烃装置的裂解气压缩机机组,为 1996 年装置兴建时引进意大利新比隆公司的设备。该设备为超高压蒸汽轮机驱动,压缩机分高、低压缸两缸,低压缸 3MCL606 ,高压缸 2BCL459 。该机组轴端密封型式采用的是德国伯格曼公司生产的机械密封和浮环联合密封,低压缸 3MCL606 使用的机械密封的型号为 SH1/200-E1 ,单端面、平衡式、双转动机械密封,在密封腔的外侧装有浮环(节流环),通过浮环径向间隙起第二密封作用( 见图 1) 。密封油的压力为 900 ~ 650kPa, 油气压差即密封油与密封气的压力差控制在 350 ~ 200kPa 。为了使机械密封得到良好的润滑和冷却作用,密封腔内必须有充分的密封油,如果油气压差偏低或密封气的压力高于密封油的压力密封腔内充满气体,密封端面就会发生干磨,产生大量热量,在很短的时间内机械密封就会烧坏。本机械密封的密封油最小流量为 32 L /min ,密封油大部分通过机械密封外环即动环外侧腔体流出并带走密封端面产生的热量,极少量的密封油通过密封端面流出进入静环内侧的腔体,最后进入油气分离器,平均最大漏油量为 50 L /d 。高压缸 BCL459 使用的机械密封的型号为 SH7/117-E1 ,单端面、平衡式、双转动机械密封。密封油的压力油气压差与低压缸的要求相同,密封油最小流量为 10 L /min ,进入油气分离器的平均最大漏油量为 13 L/d [2] 。
Ethylene joint workshop olefin plant of lanzhou pany of cracking pressor unit, for the 1996 introduction of Italy during the construction of the new equipment than pany. The device for the super high pressure steam turbine driven, compressor is divided two cylinder, high and low pressure cylinder 3 McL606 low pressure cylinder, high pressure cylinder 2 bcl459. Is the unit shaft end seal with German pany produces the mechanical seal and floating ring seal, low pressure cylinder 3 McL606 type mechanical seal to the use of the SH1/200 - E1, single, balance type, double rotating mechanical seal, on the outer edge of the sealed cavity filled with floating ring (throttling ring), through the radial clearance on the floating ring seal effect (see figure 1). Seal oil pressure is 900 ~ 650 kpa, oil and gas differential pressure oil seal and seal gas pressure difference control in 350