共查询到20条相似文献,搜索用时 171 毫秒
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为解决加氢裂化进料泵在高温》高速》高腐蚀介质运行中的泄露问题,分析加氢裂化进料泵密封的故障原因,提出改进方案.将原设计采用的单端面弹簧密封改进为双端面机械密封,根据加氢进料泵密封特点选择合适的机械密封辅助系统,给出校验密封性能参数计算的方法.此改造方案在加氢进料泵实践应用中验证了双端面机械密封在高腐蚀介质,高温,高转速下可稳定运行,满足了工业化生产的需求,对相同工况下密封方法的选型具有一定参考价值. 相似文献
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乙烯装置丙烯外送泵为GSB型立式高速泵,密封频繁泄漏,通过对其机械密封端面比压的核算,及机械密封材料和结构的分析找到了密封失效的原因,有针对性地加以综合改造,收到良好效果。该方法对解决类似的设备泄漏问题,具有一定的参考价值。 相似文献
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研制成功的小流量、高压热水循环泵,由于其工作参数高(压力100 kg/cm~2温度200℃),存在着轴向力平衡、热影响及轴端密封问题。因此,采用浮动式叶轮及单端面、流体动压式、平衡型机械密封。本文着重讨论该泵体的结构设计及高温、高压下机械密封的设计应考虑问题。 相似文献
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变工况下汽液两相机械密封端面膜压的计算与试验研究 总被引:3,自引:3,他引:3
作了变工况(泵抽空或压力波动)条件下机械密封端面运动的实验.运用流体膜的相变理论,讨论了机械密封在变工况条件下端面膜压的计算.认为端面瞬时相变是造成机械密封端面打开度失效的原因,提出了提高机械密封在变工况下的抗变能力的保护性措施. 相似文献
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The effect of a face coning on seal performance, especially energy losses as indicated by a torque, were studied by comparing torque, face temperature, leakage, and wear of a conventional, widely used flat-face seal with three coned-face seals. Experimental evaluation was performed at rotation speeds to 8000 rpm, with pressures to 2758 kPa (400 psig), using a petroleum-base turbine oil. Axial movement of the mating seal parts was recorded using a digital data acquisition system. The height of the convergent-type cone on the face of the tungsten carbide primary ring ranged from 0.51 μm (20 μin) to 5.6 μm (220 μin) over the 3.175-mm to 6.36-mm (0.125-in to 0.25-in) face width. The torque of the coned-face seal, balanced lo 76.3 percent, was an average 42 percent lower, the leakage eleven limes higher than that of the standard flat-face seal. Reducing the balance to 51.3 percent by decreasing the face width of the coned-face seal resulted in lowering the torque by an additional 44 percent and increasing the leakage 12 to 230 times, depending on the seal shaft speed. No measurable wear was observed on the face of the coned seals. All four seals operated in the stable region of the stability map. 相似文献
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《流体机械》2016,(3):11-17
维持机械密封端面间一定的膜厚是保证机械密封正常运行的关键,利用声发射技术监测得到的反映机械密封膜厚状态的信号往往信噪比很低,对其工作状态进行分类存在一定的困难。提出一种基于声发射信号利用总体经验模式分解(EEMD)和离散隐马尔可夫模型(DHMM)识别的机械密封端面膜厚识别技术。首先对声发射信号进行分帧处理,运用EEMD方法对信号进行时频分析,对分解出的子频分量分别提取时域和频域特征,再由核主成分分析法对特征参数进行优化降维,利用简化后的特征参数矢量训练各个机械密封端面膜厚状态的DHMM,最后由训练好的DHMM实现机械密封端面膜厚状态的识别,从而实现机械密封端面接触状态的监测。试验研究表明:该方法能够快速有效地判断出膜厚状态,并且需要的训练样本少,训练速度快,对实现机械密封端面接触状态的智能化在线监测具有重要的意义。 相似文献
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分析某装置反应器循环泵机械密封频繁泄漏量及端面温度高的原因。指出介质端密封载荷系数选择不当,导致密封端面比压偏小,是介质侧密封失效的主要原因;泵送环输送能力低,循环隔离液不能有效将密封摩擦热传递出去是导致大气侧端面温度高过高的主要原因。通过调整载荷系数和提高机械密封泵送能力,密封改造后使用寿命大幅提高,解决了循环泵机械密封频繁泄漏的问题。 相似文献
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Itzhak Green 《摩擦学汇刊》2013,56(3):284-293
Face seals are typically designed to be in contact at standstill. However, as speed and pressure build up, the seal faces deform from their factory flat conditions because of viscous and dry friction heating, as well as mechanical and centrifugal effects. It is imperative that such deformations form a converging gap for radial flow to ensure stable operation and to promote favorable dynamic tracking between stator and rotor. A numerical simulation is presented for the transient response of a face seal that is subjected to forcing misalignments while speeds and pressures are ramped up and down. Asperity contact forces and transient face deformation caused by viscous heating are included. A new closed-form solution is obtained for the elastoplastic contact model, which allows seamless transition between contacting and noncontacting modes of operation. The model is then used to calculate face contact forces that occur predominantly during startup and shutdown. The viscous heating model shows that the time-dependent deformation (coning) is hereditary and that it lags behind the instantaneous heat generation. The dynamic analysis provides a numerical solution for the seal motion in axial and angular modes. The eventual build up of hydrostatic pressure and coning during startup generates opening forces and moments that separate the seal faces, resulting in noncontacting operation. The reverse occurs during shutdown; however, because of the thermal time constant a seal may continue to leak even after it returns to standstill. The analysis and simulation results compare very well with a closed-form solution that predicts a critical speed of separation of contacting seals. 相似文献