Vacuum Pump Application in Refrigeration Equipment

 

Creating a vacuum is a crucial step in the production or maintenance of refrigeration equipment before charging refrigerant. This process involves connecting a vacuum pump to the system piping to eliminate non-condensable gases and moisture from the piping.

The 2XZ series rotary vane pump is a prime example of this application, as depicted in the following image.

 

The role of the vacuum pump in refrigeration equipment includes:

1. Removal of non-condensable gases:

    Non-condensable gases can elevate the condensing pressure and exhaust gas temperature, thereby impacting cooling efficiency. Additionally, they can lead to lubricating oil carbonization at high temperatures, posing risks to compressor operation and motor integrity.

2. Elimination of moisture: 

   Moisture poses a significant threat in refrigeration systems, particularly in the Freon system of vapor compression refrigeration cycles. Moisture can react with lubricants to form acids, causing corrosion and copper plating phenomena, ultimately damaging the compressor. Moreover, moisture can lead to ice formation in expansion valve ports or capillaries, resulting in ice blockages.

The vacuuming process in refrigeration systems should follow system cleaning, drainage, and pressure testing for leaks. Vacuuming verifies system air-tightness and removes air, moisture, and non-condensable gases in preparation for refrigerant charging, typically accomplished using a vacuum pump.

For smaller refrigeration systems with medium and small open or semi-hermetic compressors, the compressor itself can perform vacuuming. However, this method is not recommended if prohibited by the equipment manufacturer's manual.

Vacuum Pumping Procedure:

1. Close external communication valves (e.g., filling valves, air release valves) and open all internal system valves.
2. Remove the exhaust valve bypass hole plug, open the bypass, and connect the vacuum pump.
3. Start the vacuum pump and conduct vacuuming in stages to facilitate air removal. Ammonia system residual pressure should be less than 7.999 kPa, while Freon systems should be less than 1.333 kPa.
4. After reaching the desired vacuum level, close the bypass channel, stop the vacuum pump, remove the suction pipe, and plug the exhaust valve bypass hole.
5. Maintain the vacuum for 24 hours, ensuring that system pressure does not exceed 666.61Pa during this period. Address any rapid pressure increases promptly by identifying and resolving the underlying cause.

With its pivotal role in refrigeration equipment maintenance and production, the 2XZ series rotary vane pump continues to be a cornerstone in ensuring system efficiency and longevity.

For more information or inquiries, please visit our website at www.nuoxutech.com or contact us via email at contact@nuoxutech.com. You can also reach us on WhatsApp at +86 13849062209.

Keywords: 2XZ series rotary vane, vacuum pump, refrigeration equipment, maintenance, refrigerant charging, moisture removal, air-tightness, compressor operation.