Energy-efficient and safe packaging thanks to centralized vacuum supply

Südbayerische Fleischwaren GmbH operates four production plants in Ingolstadt, Donauwörth, Traunstein and Obertraubling. All four production sites have a combined range of 305 different products for fresh food and service counters. Südbayerische Fleischwaren delivers to a total of 1,280 retail outlets, 35 other businesses and three warehouses, each belonging to EDEKA Südbayern. Speed is the key: sophisticated logistics ensure that the ordered goods are delivered within 24 hours. Südbayerische Fleischwaren uses exclusively meat from Bavaria for all products and thus guarantees high quality and can completely trace the origin of the meat. A total of 221 DLG quality seals are the best proof of the excellent quality of Südbayerische Fleischwaren.

The Obertraubling meat products plant mainly produces raw and cooked sausages in shift operation. Between 22 and 24 tons of raw and cooked sausage products leave the factory on a daily basis. Products are packaged on four packaging lines with thermoforming machines. Originally, a vacuum booster and a rotary vane vacuum pump were each installed in these machines to supply the packaging machines with vacuum for thermoforming the bottom film and for evacuating the vacuum chamber.

Due to the very good experience with central vacuum systems in the production plant in Traunstein, plant manager Walter Stemplinger also considered the option of centralization. The main thing that triggered this was the shutdown of a packaging line during the annual maintenance work on the vacuum pumps. He also wanted to eliminate the radiated heat from the vacuum pumps from the cooled packaging room and reduce noise emissions. He contacted the vacuum experts from Busch, who had already designed and built the systems for Bayernfleisch and the meat plant in Traunstein.

The space conditions in the production and packaging areas posed a challenge. To be able to satisfy the increasing demand, the meat plant in Obertraubling has undergone a series of expansions in recent years. Nevertheless, there was no room for the installation of a central vacuum system in the packaging area, which was last expanded in 2015. The vacuum experts from Busch then designed a vacuum system (Fig. 1) that fitted into a 20-foot container. Busch supplied this vacuum system, essentially consisting of four PANDA vacuum boosters, four R5 rotary vane vacuum pumps as backing pumps and a control cabinet completely mounted in the container (Fig. 2). The buffer tanks were mounted on top of the container and all four packaging lines were connected to them.

The packaging chambers are evacuated in two steps with two vacuum supply lines. In the first line, there is a constant so-called rough vacuum of 30 millibars. This enables fast evacuation to the rough vacuum level. Once this has been achieved, the system switches to the second line with a vacuum level of 4 millibars. This two-stage pressure equalization method facilitates short cycle times. The buffer tanks on the container and the volume of the 18 to 25 meter long suction lines ensure that the necessary vacuum levels are permanently present in the lines. For the thermoforming of the bottom film, the rough vacuum level is completely sufficient, so that the forming tools are only exposed to this vacuum. The system is operated according to demand. Depending on the pressure, the individual vacuum pumps are switched on or off using pressure transmitters. This means that, in contrast to the previous decentralized vacuum supply, not all vacuum pumps are in operation at all times.

The vacuum supply is now fully redundant. This means that for the maintenance of individual vacuum pumps, these can simply be uncoupled via valves without this affecting active operations. The service technician no longer has to enter the hygienically sensitive packaging area. Thus, the annual service of the Busch vacuum supply is carried out during ongoing operation. After the plant was started up in 2018, the production plant manager in Obertraubling can today confirm: "If service work is being performed on the vacuum supply, nobody notices this at packaging lines."

It was possible to significantly reduce noise emissions by removing the individual vacuum pumps from the packaging room. The cooling of the packaging room could now also be reduced because the heat emitted by the vacuum pumps is no longer emitted into the ambient air. This and the demand-driven control of the vacuum supply contribute to a reduced energy consumption. Due to the energy savings and the easy service during operation, Südbayerische Fleischwaren has now also installed an extremely economical vacuum supply at its second production plant. In the event of a vacuum pump failure, further packaging could be performed on the packaging lines without restrictions. Thanks to a service contract with Busch, Walter Stemplinger can be sure that the vacuum supply is always fully functional.