Safe packing with oxygen
Safety, reliability and profitability: these are the main requirements on technical meat processing facilities. This also applies to packaging lines used to pack meat products in MAP packages, especially to the vacuum pumps that generate the vacuum. The oxygen vacuum pumps in the R 5 series made by Busch are state-of-the-art.
Packaging sausages and convenience foods with modified atmospheres is a common method for increasing shelf-life. Film packages are first evacuated and then refilled with other gases. Typically, this “modified atmosphere packaging” (MAP) technique uses carbon dioxide (CO2), nitrogen (N2), oxygen (O2) or various mixtures of these gases. Using oxygen for the gassing process presents certain safety risks because there is a danger of explosion as of an oxygen concentration of 21 percent. Packaging machine and vacuum pump manufacturers have developed various concepts to guarantee absolute process safety for such applications. Busch has now developed a special series of vacuum pumps for packaging in oxygen atmospheres. According to the manufacturer, these vacuum pumps set standards not only in safety, but also in reliability and profitability.
One of Germany’s largest sausage producers, with a production capacity of over 100 t per day, has used Busch’s rotary vane vacuum pumps for packaging its products for over ten years. In 1996, the company centralized its vacuum supply. This central system provides the vacuum for the thermoformer machines in the 17 lines used to package meat and sausage products. Convenience products are packaged with various types of protective gases, including oxygen, on five additional tray packagers. These products are evacuated by four similarly constructed Busch R 5 rotary vane vacuum pumps made for use with oxygen, which are located in a partial story directly above the packaging room.
For operators of such vacuum pumps, there is one very important difference from when standard pumps are used: if a vacuum pump malfunction occurs, inflowing oxygen must not be able to come in contact with mineral oil. This is why the pumps use a completely synthetic lubricant, a so-called perfluorpolyether (PFPE).
Busch’s four oxygen vacuum pumps have been used in three-shift operation for over ten years and achieve an average operating life of 6,000 hours per year. The operator relies on the manufacturer’s customer service for all pump maintenance tasks. Twice a year, the rotary vane vacuum pumps undergo a maintenance procedure that is limited to only several inspection processes.
During the actual maintenance, filter elements are prophylactically exchanged. Changing the synthetic lubricant is unnecessary because perfluorpolyether is highly inert and does not combine with other elements, e.g. oxygen. R 5 rotary vane vacuum pumps for oxygen applications are thus lubricated for their entire operating life. This is an important aspect for all those responsible for technology in meat- and sausage-producing companies because it eliminates the costs of lubricant exchange. Only in the case of too little lubricant – a situation that can occur when filter elements are changed – must more lubricant be added.
The meat processing industry rigorously pursues the concept of producing fresh products. Its aim is to ensure that no more than 24 hours go by between the production of wares and their display on the sales counter. This is one of the reasons that production must take place on Saturdays. This enables fresh products to be placed in markets on Mondays.
For technical equipment, this means that the vacuum pumps must be one hundred percent reliable. The breakdown of only one pump would mean the halt of a packaging line, thus resulting in a production stop, supply shortages and possibly even the spoilage of the goods. The technology experts in sausage production have exceptionally positive experiences with the Busch rotary vane vacuum pumps: none has ever malfunctioned. This is due to both the high quality of the vacuum pumps as well as the prophylactic maintenance by Busch’s customer service department. Even after an operating life of over ten years and far more than 60,000 operating hours, no reduction of the rotary vane vacuum pumps’ performance, reliability or operating safety has occurred.