什么是泵气氮
气蚀不是影响泵系统的新现象，而是一个问题太多了。由于流动液体的部分压降在泵内产生气泡时，就会发生这种情况，从而导致微小的气泡。气泡移动，压力增加，气泡瞬间爆炸。蒸气气泡的塌陷侵蚀了叶轮表面和泵外壳。如果在泵入口处发生强烈的气态，泵的性能会降低，这可能导致过早的泵浦故障。
由于NPSH的要求，最常见的是带离心泵的泵空气，但也可以在正位移泵中找到。当叶轮吸入液体的温度和压力等于蒸气压时，就会发生这种情况。它可以在低压和正常工作温度下发生。了解不同类型的泵气蚀和应采取不惜一切代价采取的步骤非常重要。
TYPES OF PUMP CAVITATION
1. Air Aspiration Cavitation
空气是不可预测的，有时可以通过故障阀或其他弱组件吸入泵中。空气最终将开始形成气泡，然后泵叶轮在压力下弹出。防止这种气蚀类型的一些技巧包括：
- 检查所有O形圈和机械密封
- Ensure all piping is crack-free
- Make sure joint rings have not perished on any suction piping
- Regularly checking any components that will likely fail at some point
2. Internal Re-Circulation
这种类型的空化阻止泵说charging at your desired rate, meaning that the liquid will now re-circulate around the impeller. The liquid travels through low- and high-pressure zones resulting in heat and high velocity, which in turn creates vaporized bubbles. Some tips to prevent this type of cavitation include:
- 在泵上打开一个受限制的放电阀
- 运行太近的闭门头
- 闭合排放阀
- An over-pressurized header
- 解开下游过滤器
- Assess pressure at the discharge line
3.湍流
Any kind of turbulence within a pump is never a good sign. If the system has been designed with parts that are inadequate for the amount of liquid you’re trying to pump, it will in turn create vortexes in said liquid. These vortexes will become turbulent and experience major pressure differences throughout the system. This all leads to erosion of solid materials over time. Some tips to eliminate turbulence in your system include:
- 设计泵吸管管道和路由以避免过多的湍流
- Have sufficient NPSHa
- 尊重最大允许流量限制
- 增加泵抽吸线大小
4. Vane Syndrome
如果泵叶轮的直径太大，则会发生这种气态，或者外壳太厚。这里的两个问题都在整个泵外壳中创造了更少的空间。然后，该泵将从可用的少量自由空间中的液体中的速度增加，这又导致总压力降低。在这里，您会看到气泡气泡，因为较低的压力现在正在加热液体。防止这种空气的一些技巧包括：
- 叶轮叶片尖端之间的可用空间
- Ensure the free space between your impeller and its housing is 4% of the impeller’s diameter or more
5.汽化
Also called inadequate NPSHa (Net Positive Suction Head Available) cavitation – this is the most common form. This type of cavitation occurs when a centrifugal pump imparts velocity on a liquid as it passes through the eye of the impeller. Liquid gets vaporized quickly if the impeller is not functioning correctly, which then creates tiny shock waves. Some tips to prevent cavitation due to vaporization include:
- npsha> npshr + 3英尺或更多安全保证金
- Lower temperature
- Raise liquid level in suction vessel
- Change out pump type
- 减少电动机RPM
- 使用叶轮诱导剂
- 增加叶轮眼的直径
CONCLUSION
Regularly checking on the performance of your pump and maintaining a reliable maintenance process is the best way to identify early warning signs of cavitation. Some common symptoms of cavitation include: Decreased flow or pressure, unexpected vibrations, seal/bearing failure, noise, erratic power consumption and impeller erosion.
You will significantly increase the efficiency and lifespan of your pump by taking the necessary steps to prevent pump cavitation. Detect a failing pump before it becomes a major problem. If you need any help identifying which components you need for your system, don’t hesitate to在这里与我们的一位泵专家联系。
避免空化的唯一方法是考虑到预防空化的预防 - 简单明了。在工业泵市场空间中的数十年经验，安德森流程具有独特的位置，即使是最复杂的液体过程设备挑战，也可以为系统设计提供卓越的系统设计。泵空气不会到任何地方 - 立即与我们联系，以开始设计最适合您应用的系统的过程。