变工况时气液两相机械密封端面动压实验分析

在理论分析变工况时机械密封动环密封圈摩擦力和比压的变化 ,以及端面轴向力平衡变化的基础上 ,采用 1GX70非平衡型机械密封 ,在实验室模拟变工况条件下开展了气液两相机械密封端面动压实验。实验结果表明 ,变工况时处于气液两相的机械密封 ,因端面间液膜闪蒸而导致端面开启 ,动、静环不再平行 ,动环密封圈摩擦力增大 ,动环追随性遭破坏致使密封失效 ;机械密封的动压膜压沿收敛间隙呈正弦分布 ,计算变工况密封开启力时不但要考虑密封端面闪蒸造成沸腾区压力的影响 ,还要考虑动压的影响

Test analysis of dynamic pressure on the end surfaces of mechanical seals for gas-liquid phases under varied working conditions

Based on analysis on varying of friction, specific pressure of dynamic sealing ring of the mechanical seals and balance of axial force on end surfaces, a unbalancing mechanical seal, 1GX70, is used. Simulating tests of dynamic pressure on end surfaces of gas-liquid mechanical seal under varied service conditions are implemented. Test results show that: (1) End surfaces of the mechanical seal are opened because of flash vaporizing of liquid membrane between end surfaces in gas-liquid phases under varied working conditions, (2) The running and static rings are unparallel anymore, (3) friction of running rings is increased, (4) The seal failure is occurred because of damage of following of running ring, (5) and dynamic membrane pressure distributes according to sinusoid along to convergent clearance. The influences of flash vaporizing on boiling pressure, and dynamic pressure should be considered when calculating opening pressure of the seal under varied service conditions.