Vacuum pumps have long been used to remove oxygen from plastic packaging in order to extend the shelf life of food products. The vacuum packaging helps protect flavor and eliminate or reduce exposure to bacteria and other elements that may alter the food’s taste and quality.
Traditionally, food packaging plants have used rotary vane vacuum pumps for these processes, turning the pumps on in the morning and running them throughout the day.
How rotary vane pumps work
Rotary vane pumps are positive-displacement pumps that consist of vanes inserted into an offset mounted rotor inside the pump cylinder. Using centrifugal force, the vanes slide out of the rotor while sealing and maintaining contact with the pump housing. Air is trapped between the rotor and vanes, which increases cell volume and creates chambers where fluid enters.
The chambers decrease in size as the vanes continue to rotate and retract, causing the trapped air to exit through the discharge port. Because the vanes are in constant contact with the pump’s rotor and housing, this creates wear on the pump.
Testing rotary screw pumps
In recent years, meat packaging facilities have tested rotary screw vacuum technology as an alternative to vane pumps. Many have noticed a significant increase in reliability, energy efficiency and lower maintenance costs.
- Reliability – Rotary screw vacuum pumps have a non-contacting mechanism within the pump housing so there’s minimal wear and less need for maintenance.
- Energy efficiency – Food packaging plants often operate 25 hp rotary vane vacuum pumps. Switching to a 15 hp rotary screw pump with Variable Speed Drive (VSD) technology can help customers achieve more flow at a reduced install power of 40 percent less.
- Lower maintenance costs – Rotary vane pumps have maintenance intervals of 750-1,500 hours and are usually overhauled every 3-4 years, or every 16,000 running hours, whereas rotary screw pumps require maintenance at 8,000 hours and can run 48,000 hours before an overhaul.
Replacing rotary vane pumps with rotary screw can be a reliable and cost-effective solution for your food packaging facility. Plants making the switch have experienced longer periods between overhauls, higher flow rates with minimum absorbed power and an increase in uptime. To learn more, contact a vacuum solutions expert today.
