What Causes Liquid Ring Pump Cavitation and How To Prevent It?
Liquid ring vacuum pumps are
commonly used in a variety of industries for applications that require the reliable vacuum. These pumps work by using a liquid ring to
compress air and other gases in the system. However, these pumps can sometimes cavitate, which can lead to damage and decreased
efficiency. In this article, we will explore the reasons why liquid ring vacuum pumps cavitate and how to prevent it from happening.
What is cavitation in liquid ring vacuum pumps?
Cavitation is a process that occurs when the pressure at the inlet of a liquid ring vacuum pump drops below the vapor pressure of the liquid
being used to create the vacuum. This can happen when there is a sudden increase in demand for vacuum or If the amount of non-condensable
gas is too small. When cavitation occurs, vapor bubbles form in the liquid ring, which then collapse and cause damage to the impeller and
other parts of the pump. This can lead to decreased efficiency, reduced capacity, and even failure of the pump.
Why do liquid ring vacuum pumps cavitate?
There are several reasons why liquid ring vacuum pumps can cavitate. One of the most common reasons is an increase in demand for the vacuum.
When the demand for the vacuum increases, the pressure at the inlet of the pump decreases. If the pressure drops below the vapor pressure of
the liquid being used to create the vacuum, cavitation can occur.
Another reason for cavitation in liquid ring vacuum pumps is poor design or maintenance of the pump. If the pump is not properly designed or
maintained, it can create conditions that lead to cavitation. For example, if the impeller is damaged or worn, it can increase turbulence in
the liquid ring, which can cause vapor bubbles to form and collapse.
Similarly, if the seal fluid being used in the pump is contaminated or has a high vapor pressure, it can also lead to cavitation.
Contamination can increase turbulence in the liquid ring, while a high vapor pressure can make it more likely that the pressure at the inlet
of the pump will drop below the vapor pressure of the liquid.
How to prevent cavitation in liquid ring vacuum pumps
Preventing cavitation in liquid ring vacuum pumps requires proper design, maintenance, and operation of the pump. Here are some steps that
can be taken to prevent cavitation:
Proper pump design - The pump should be designed to handle the maximum demand for the vacuum. This means that the pump should be sized
properly for the application and the liquid being used to create the vacuum. The impeller should be properly designed and maintained to
minimize turbulence in the liquid ring.
Proper seal liquid - The liquid being used in the pump should have a low vapor pressure relative to the operating conditions and be free of
contaminants. This will help to minimize the likelihood of cavitation occurring.
Proper maintenance - The pump should be regularly inspected and maintained to ensure that it is operating properly. This includes vibrations
levels, checking the impeller for damage or wear, checking the liquid level in the pump, cleaning the heat exchanger and replacing any worn
or damaged parts.
Avoid sudden changes in demand - Sudden increases in demand for the vacuum should be avoided. This can be achieved by properly sizing the
pump for the application, and by also using control systems like pressure control valves or variable speed drives to manage the demand for
the vacuum.
Overall, cavitation is a very common problem that can occur in liquid ring vacuum pumps. It can lead to damage to the pump and decreased
efficiency. However, by taking steps to properly design, maintain, and operate the pump, it is possible to prevent cavitation and ensure
optimal performance.
Do you have an idea for our #expertcorner? Let
us know!
Who we are and how Ash Air can help your business!
Ash Air has been around in New Zealand since 1979, and we’ve grown into a nationwide company with international support and a
reputation for quality and reliability.We look after all things compressed air for your business!
Reciprocating, Screw, air compressors
Vacuum pumps
Nitrogen
An extensive line of air treatment components
Ash Air's range of Chicago Pneumatic, Alup, Pneumatech, and Quincy compressors are used extensively around the world in industries
ranging from oil and gas to food, automotive and farming, and we bring you these world class compressors here in the land of the long white
cloud.Our technicians are compressed air equipment experts and are dedicated to addressing customer needs. Supported by a 13 locations
nationwide, Ash Air offers one of the widest selections of compressed air equipment and parts available today in New Zealand.
Reliability and Efficiency
With Ash Air compressors, you can count on reliability and high performance for even the most demanding applications. We focus our
efforts on the following:
A liquid ring vacuum pump is a powerful and steadfast piece of equipment that, if well maintained, can provide years of dependable
performance. Whether you purchase a large or small unit, you can rely on a vacuum pump for smooth, consistent and relatively quiet operation
for many months on end between each inspection.
Read More…
Just like any other equipment, a compressed air installation also requires the necessary maintenance work during its entire
lifespan. Even though maintenance costs are only about 5 to 10% of a machine's annual operating costs, failure to budget for
maintenance can have potentially disastrous consequences.
Read More…