Pig processor centralises vacuum supply

Pini Polonia operates three production facilities in Poland which slaughter and process 1000 pigs/h. The newest facility was commissioned in April 2015, and it manufactures cooked ham, salami and other sliced meat products. Located close to the company’s existing abattoir and processing centres, the site employs 850 staff and is equipped with the latest technology, producing 130 tons of cooked ham and 60 tons of salami in a two-shift system.

The Pini Polonia management team was certain from the outset of project planning that a centralised vacuum system for the 24 packaging lines would be the best solution. In comparison to directly mounted vacuum pumps, centralised systems offer higher levels of energy efficiency, hygiene and performance.

Pini Polonia chose a Busch system, and Busch vacuum specialists were involved from the start, helping with specifications for the pipework, the location of the centralised system and the development of the controller unit. When the new plant started production, it was equipped with one of the most modern and efficient centralised vacuum systems in Europe.

Busch centralised vacuum system at Pini Polonia.

As the individual packaging machines are not in close proximity to each other, it was decided to implement a so-called partial decentralisation. Panda vacuum boosters are mounted directly to the packaging machines, and all the R 5 rotary vane vacuum pumps are located in a separate room. This arrangement allows the rotary vane vacuum pumps to work at maximum efficiency, resulting in short evacuation times at every packaging machine.

The R 5 rotary vane vacuum pumps maintain a permanent prevacuum of 50 mbar throughout the pipework system. The Panda vacuum boosters operate on demand and activate only when a vacuum of 5 mbar is required in the chamber or the packaging. They evacuate rapidly from the prevacuum of 50 mbar to the final pressure within the packaging of less than 5 mbar. This two-stage evacuation arrangement and the controller system allow packaging cycle times to be reduced substantially.

A second vacuum network for foil thermoforming is operated independently of the packaging vacuum. The thermoforming vacuum ring is maintained at 130 to 200 mbar, a considerably higher pressure than the level required for packaging. All the vacuum pumps required for the thermoforming of foil to trays are integrated into the centralised vacuum system and are thus located away from the packaging areas.

Energy efficiency

Due to their working principle, centralised vacuum systems require fewer vacuum pumps than decentralised systems. The two-stage evacuation process permits the use of rotary vane vacuum pumps with a smaller volumetric displacement, so the motor size can be reduced. The system controller maintains a vacuum of 50 mbar in the pipework system, which acts as a vacuum reservoir for all the packaging lines.

Only the number of vacuum pumps required to maintain 50 mbar are active at any one time. As the packaging lines do not always run with short cycle times and high throughput, normally only a few of the vacuum pumps are in operation.

A further energy saving is achieved by vacuum supply centralisation: the vacuum pumps operate in a separate room, so no heat is given off to the packaging area. The air-conditioning unit of the packaging area has less work to do and thus requires less energy.

Improved hygiene

As the vacuum supply is centralised, no servicing of the rotary vane vacuum pumps is carried out in the clean areas of the packaging and processing lines. Any possibility of food contamination by oil aerosol (by equipment misuse) is excluded.

Maintenance

Centralised vacuum systems have a modular construction. Individual modules may be disconnected for maintenance purposes, in which case a standby unit will activate automatically. Servicing tasks can thus be carried out without affecting the packaging line output. As the vacuum pumps in a centralised system are subjected to lighter loads, the servicing intervals are longer than those of decentralised systems. The external location of the centralised vacuum supply is an additional advantage, as maintenance work does not cause production downtime or contamination of clean areas.