Vacuum Pump Cavitation and Its Prevention

While traveling through a vacuum pump, the bubble may form in the liquid due to several factors, such as vapor exposure and pressure variances. When these bubbles burst, pressure differences are caused as well. This formation and bursting of bubbles in fluid is called cavitation in vacuum pumps.

Cavitation can cause damaging effects to the system and its internal components as well as affect the production process. It will reduce system reliability and durability and, therefore, should not be ignored or left unattended. 

Understanding cavitation is crucial for maintaining vacuum pump efficiency, ensuring smooth operation, and preventing costly system failures.

Why is Cavitation a Critical Issue?

In addition to the above issues, cavitation may also lead to rapid vibration and noise while the vacuum pump operates. This damages the internal parts of the vacuum system and reduces its operational life.

Besides, the lower productivity of the vacuum pump will translate into economic losses. This amount will be larger due to the unnecessary expenses incurred on the replacement of damaged parts.

Since vacuum pump efficiency and cavitation are related to one another, you must not ignore such occurrences. You must respond as soon as it happens and take proactive steps to prevent the vacuum pump from failing or shutting down completely, thereby unsettling production processes.

What Is Cavitation in Vacuum Pumps?

Definition and Explanation of Cavitation

As said earlier, the formation and explosion of bubbles inside a vacuum pump is called cavitation. When the system pressure is lower than the vapor pressure of the liquid flowing inside the system, bubbles that explode inside are created. This is a continual process and can lower the performance level and output of the vacuum pump and even destroy it.

How Cavitation Occurs in Vacuum Systems

When the inlet pressure is very low within the vacuum systems, cavitation occurs. It may also happen if the velocity of the fluid is excessively high, as it will reduce pressure. Technically speaking, cavitation in vacuum pumps occurs if there are flaws in the system design or the working condition is imperfect.

Causes of Cavitation in Vacuum Pumps

Low Suction Pressure and High Vapor Pressure

One primary reason for cavitation to occur in vacuum pumps is high vapor pressure. It is also caused when the suction pressure is lower than the vapor pressure of the liquid resulting in the violent formation and explosion.

Incorrect Pump Sizing or Design Issues

Cavitation may also occur if the size of the vacuum pump is improper according to the application. This will affect the flow rate of the liquid and fluctuate the pressure within.

Rapid Pressure Changes in the System

If unstable conditions are created within the system due to abrupt changes in the pressure of the vacuum system, it will also cause cavitation.

Presence of Air or Gas Pockets in the Pumping Chamber

Sometimes, gas or air may be entrapped in the liquid, affecting its flow rate. This will, once again, impact the pressure dynamics inside the system and enhance the chances of cavitation.

Unwarranted Speed of the Pump 

Unnecessary high speed causes turbulence in the liquid and will, in turn, lower the localized pressure. This will create bubbles and cavitation. 

Effects of Cavitation on Vacuum Systems

Increased Noise and Vibration

The vacuum pump will start emitting unusual noise and even vibrate noticeably when cavitation occurs. This will cause system wear due to higher mechanical stress.

Reduced Pump Efficiency and Performance

The efficiency of the vacuum pump will be reduced significantly due to cavitation. This is attributed to the disruption in the fluid flow. Such inefficient performance will subsequently lower output and unnecessarily increase the consumption of energy.

Damage to Impellers and Internal Components

Seals, impellers, and other components inside the vacuum pump are susceptible to damage due to cavitation. This is because the high impact of the shock waves will corrode them. 

Lower Durability and Higher Cost of Maintenance 

Cavitation will cause greater mechanical wear, thereby reducing the life of the vacuum pump. This will translate into higher repairs and costs.

How to Prevent Cavitation in Vacuum Pumps

Pick the Right Pump According to Your Application Requirements 

Know your application requirements first, and then select a vacuum pump that will accommodate all its needs. This will ensure proper fluid flow and pressure, thereby minimizing cavitation likelihood.

Maintaining Optimal Operating Conditions

Ensuring appropriate working conditions and monitoring your vacuum pump regularly is another way to prevent cavitation, as it will prevent variances in flow rates, temperature, and pressure.

Ensuring Correct Suction Pressure and Fluid Temperature

To prevent cavitation, ensure that the suction pressure is proportionate to the vapor pressure of the liquid. Also, the temperature of the fluid should be controlled. 

Removing Air and Gas Pockets from the System

Degas fluid and remove air pockets from the fluid to ensure smoother operation and prevent cavitation.

Regular Maintenance and System Inspections

There is no alternative to routine checks to prevent cavitation as that will allow early detection of cavitation signs and timely maintenance.

Take Action Now!
Preventing cavitation keeps your vacuum pump efficient and avoids costly repairs. Follow these steps:

• Check Your System: Identify any potential cavitation issues.

• Get Expert Advice: Consult professionals for the best solutions.

• Stay on Track: Perform regular maintenance to prevent problems early.

Need more guidance? Contact our team today to keep your vacuum pump running at its best!

FAQs

1. What is cavitation in vacuum pumps?

The formation and explosion of bubbles in the fluid that results in a fall in pressure and mechanical damage is called cavitation in vacuum pumps.

2. How can cavitation damage a vacuum pump?

Cavitation will result in shock waves and vibration. These will degrade the seals, impellers, and other internal parts of the vacuum pump, thereby damaging the entire system.

3. Are there any tell-tale signs of vacuum pump cavitation?

Noticeable vibration, abnormal noise, and lower output are crucial signs of cavitation in vacuum pumps.

4. How do I prevent cavitation in my vacuum system?

You must take proactive measures to prevent cavitation in the vacuum system, provided you have chosen the right type of pump for your application in the first place. Monitor its operation regularly to pick up the signs of cavitation early. 

5. Which is the best pump type for evading cavitation?

Using vacuum pumps with proper design to ensure pressure stability is the best way to prevent cavitation.