Busch vacuum system cuts energy consumption by 70%

The Feinkost Dittmann delicatessen company dates back to 1901, when Carl Dittmann opened a delicatessen in Wiesbaden, Germany. Today, the family-run business is the German market leader for olives, antipasti, capers, garlic and anchovy specialities.

At its production plant in Taunusstein near Wiesbaden, 320 employees produce different antipasti specialities made from olives, feta cheese, garlic, pepper and dried tomatoes, which are dispatched to national and international retail store chains and discount stores in over 30 countries.

Products are manufactured as preserves in glass jars or as fresh products packed in plastic trays. During the packing process in the ‘fresh’ department, air is sucked out of the packaging trays before a CO₂N₂ protective gas mixture is added to the package. Synthetic material foils are then used to give the packaging a gas tight seal before the packaging is closed with an additional plastic cover. This type of packaging guarantees that the oxygen content is under 1%, significantly increasing shelf life.

In total, four tray sealers are used for packing during a two-shift operation. The vacuum required for this is generated by six oil-lubricated rotary vane vacuum pumps with 5.5 kW of motor power each. They were originally installed directly on the packaging machines; however, for hygienic reasons and to reduce the thermal load in the production rooms, these vacuum pumps were later installed in a separate room above the production room and connected to the packaging machines using a pipe network.

Andreas Lutz, the technical project manager in the production plant, was dissatisfied with this solution because the vacuum pumps still required high levels of maintenance. Also, fluctuations or failures in the vacuum network were first noticed if one of the packaging machines showed an error message and automatically shut down. This led to repeated production downtimes on individual packaging lines.

He charged the vacuum specialists from Busch with the task of offering a more reliable and efficient solution, using the existing pipe network. In addition, the vacuum supply was to be designed in such a way that connection of further packaging machines would be possible if production capacity were to grow.

Busch recommended a central vacuum system with four Mink claw vacuum pumps. These have the basic advantage that they do not require an operating fluid such as oil in the compression chamber, eliminating much maintenance work such as oil checks, oil changes, oil filter changes and the costs for procuring and disposing of oil and filters.

Central vacuum system with Mink claw vacuum pumps from Busch.

Mink claw vacuum pumps also use non-contact operation, meaning there are no parts in the compression chamber that come into mechanical contact and thus cause wear. The non-contact operation also enables a high degree of efficiency and therefore requires less motor power than conventional vacuum pumps.

Three vacuum containers with a volume of 3000 L each are upstream from the Mink claw vacuum pumps. This ensures that sufficient vacuum levels are immediately available at the machines when they are needed.

Previously, all six rotary vane vacuum pumps were in operation an average of 15 h/day. The Mink vacuum pumps in the new central system are controlled so that only those currently needed for the actual vacuum requirements are running.

Two of the vacuum pumps with standard motors are responsible for the so-called base load. The other two vacuum pumps are frequency controlled and ensure fine adjustment of the vacuum requirements by adjusting their speed. With this intelligent solution, the pumping speed of the central vacuum system adjusts itself to the current requirements.

During normal operation, all four vacuum pumps never need to operate at full load, so Feinkost Dittmann’s central vacuum system has sufficient power reserves to connect further packaging machines. There is a plan to additionally connect a vacuum filler for glass preserves, which would eliminate the need for the current decentralised liquid ring vacuum pump installation with 7.5 kW drive, creating further energy savings.

After more than two years of operation, project manager Andreas Lutz said that energy requirements have been reduced by more than 70%, alongside a drastic reduction of maintenance efforts, increased reliability and no failures or breakdowns.