石油化工泵备用机械密封及报警系统的研究

为防止和监控关键泵用机械密封的突然失效，研制了备用机械密封及报答系统。该系统是在主密封后面安装一个非接触式备用机械密封，主密封与备用密封间有一个辅助密封腔，与压力报警装置相连。当主密封失效时，辅助密封腔内压力上升，驱动备用密封的两端面立即贴合进入工作状态，起到二次密封的作用，防止危险介质向大气泄漏并保证主机连续运转。此系统比传统的双端面密封及串联密封的结构简单，安装方便，给出了非接触式备用机械密封的设计方法和计算公式，得出了备用密封的最佳参数范围。试验及现场检验表明，研制的备用密封工作多数在理论上与实际相一致。

STUDY OF STANDBY MECHANICALSEAL AND SEALING SYSTEM OF PETROCHEMICAL PUMP

The standby seal and warning system are developed to monitor the failureof key pump mechanical seals. A non-contacting standby seal is set at the back of a primaryseal.There is an auxiliary seal chamber between the primary seal and standby seal in thissystem. The chamber links with a pressure warning device. When primary seal fails and thepressure in the chamber goes up, the standby seal faces can be closed, which causes a whistleto sound and a fluorescent coloured indicator to activate simultaneously. The system issimpler in design and more convenient in use than the double-face mechanical seal and tandemmechanical seal. The design procedure and calculation formulas of standby seal are given,Theoptimal values of standby seal are obtained The field trial showed that the predicated values ofall parameters are identical with their actual values of the standby seal.