Industrial Utility Efficiency

Two Vacuum System Optimization Case Studies from Europe


Case Study #1: Enormous Savings in Water Consumption with Modern Vacuum Technology

Figure 1. Degassing tank (center of picture) at one of the filling plants at Rheinfelsquellen

Sustainability and environmental protection are not just words to Rheinfelsquellen H. Hövelmann GmbH & Co. KG but, as one of Germany's largest private wells, a genuine concern. This is demonstrated, for example, by the DIN ISO 50001 energy management system already introduced in 2012 and the DIN ISO 14001 certification of the environmental management system. Saving resources is thus a high priority at Rheinfelsquellen, which was just one of the reasons for drastically reducing the consumption of water from the municipal water supply.

By using state-of-the-art vacuum technology for degassing mineral water, it has been possible to save an average of 3,000 cubic meters of water per filling plant per year. The solution was to replace the existing liquid ring vacuum pumps with MINK claw vacuum pumps from Busch Vacuum Solutions.

The roots of Rheinfelsquellen go back to 1905. The family-run business has developed into one of Germany's largest private wells, and the owners are the fourth generation of the family to run the company. Around 700 million liters of mineral water and other non-alcoholic beverages are produced each year. The product range includes the Sinalco, Aquintel and Staatl. Fachingen brands, which are sold throughout Germany, as well as brands sold in North Rhine-Westphalia such as Rheinfels Quelle, Römerwall, Burgwallbronn, Ardey Quelle, Urquell and Rheinperle. 

Filling takes place at the Duisburg-Walsum site across a total of eight filling plants for returnable and non-returnable PET bottles, glass bottles, and returnable kegs with a total capacity of 210,000 bottles per hour.

Figure 2. MINK claw vacuum pump for degassing the well water in the degassing tank.

Liquid ring vacuum pumps were used at all filling plants for degassing the well water in the degassing tank (Fig. 1). Their operating principle requires water as an operating fluid in order to generate vacuum. This water is drawn from the public water network and then goes into the public sewer system as waste water. The water was fed through the vacuum pumps in a partial circuit. 

However, fresh water had to be supplied permanently in order to avoid a rise in the water temperature. This is necessary because the performance of liquid ring vacuum pumps depends on the water temperature. They are technically designed to achieve the highest vacuum level at an operating fluid temperature of 59°F (15°C). The warmer the water in the circuit, the poorer the vacuum. However, a certain vacuum level is required to extract all gases from the well water nebulized in the degassing tank. 

Rheinfelsquellen recorded an average water consumption of 3,000 cubic meters per bottling plant per year. The costs for this amounted to an annual average of 10,000 Euro per filling plant. In order to limit or completely avoid this water consumption, the topic of dry vacuum pumps was addressed. Busch Vacuum Solutions' MINK claw vacuum pump seemed to be the perfect solution. This vacuum pump does not require any operating fluid in the compression chamber, so it runs without water – or any other operating fluid. 

First, a MINK claw vacuum pump (Fig. 2) was installed in a plant on a trial basis. A liquid separator was installed upstream of it, as it can always happen that small amounts of well water are also suctioned in. This liquid separator prevents water from getting into the vacuum pump. It works completely self-sufficiently. If a certain amount of water has accumulated in it, it empties itself automatically during ongoing operation without affecting the separation performance. This means that the water is degassed completely automatically during three-shift operation on five or six working days per week.

Figure 3. Operating principle of the operating fluid-free MINK claw vacuum pump

Following the successful operation of the first MINK claw vacuum pump, Rheinfelsquellen has converted three more filling plants to this modern vacuum technology, thus drastically reducing water consumption. MINK claw vacuum pumps are nearly maintenance-free due to their operating fluid-free and contactless operating principle (Fig. 3). A maintenance contract stipulates that all vacuum pumps are checked once a year by a Busch service engineer to ensure that they are functioning properly. In addition, a 24-hour service hotline is available to customers.

Case Study #2: Vacuum Packaging with the Latest Vacuum 4.0 Technology

Vinzenz Murr GmbH has converted its existing central vacuum system to the latest Vacuum 4.0 technology to generate vacuum for packaging processes. The system now uses the latest R5 PLUS vacuum pumps, which are pressure-regulated to keep the vacuum for all packaging machines exactly and permanently at the pre-programmed level – while also being extremely energy efficient.

Vinzenz Murr GmbH has been producing meat and sausage products for almost 120 years [2020]. Company founder Vinzenz Murr opened his first butcher shop in Munich in 1902. Today, Vinzenz Murr GmbH is not only one of the largest producing butcheries in Munich and southern Bavaria, but with over 2,000 employees also one of the largest employers in the industry. Since 1970, Vinzenz Murr has been producing its meat and sausage products in the Munich district of Obersendling. Products are sold almost exclusively through the 270 branches in Bavaria.

Since 2004, Vinzenz Murr has been using a central vacuum system from Busch Vacuum Solutions to supply vacuum to all the packaging machines in the butchery plant in Obersendling. This central vacuum supply consisted of a vacuum system with three R5 rotary vane vacuum pumps and three vacuum boosters. The vacuum system was operated using a cascade control unit. This means that only as many vacuum pumps were in operation as were necessary for the current demand. The vacuum pumps involved were switched on or off as required. A vacuum chamber with a volume of two cubic meters served as a buffer so that the necessary vacuum level is immediately available in the respective packaging chambers when needed. So far, four large thermoforming machines have been supplied with vacuum.

Figure 4. Modern vacuum technology with the latest PLUS Master Control unit for efficient central vacuum supply according to the actual demand.

When moving the vacuum system to another room, Managing Director Alexander Brandl decided to swap the rotary vane vacuum pumps equipped with standard motors for frequency-controlled rotary vane vacuum pumps to be able to adjust the performance of the vacuum system more precisely to the actual demand. This is because the packaging machines are used to package products ranging from several kilos in weight to small portion packs for self-service counters. This means that very different tools are used for packaging and therefore the volumes of the packaging chambers vary considerably. Due to relatively small quantities, the total volume of all packaging machines changes frequently and therefore also the vacuum system's power requirement.

Managing Director Alexander Brandl decided on the latest generation of intelligent vacuum pumps: the R5 PLUS from Busch Vacuum Solutions. The reasons for this were obvious. Not only has he had good experiences with Busch products over many years, he was also impressed by the easy handling of such systems via touchscreen.

The new system has now been in operation since June 2020. Thanks to pressure control, each individual R5 PLUS can precisely maintain the specified vacuum level and compensate for changing pumping speeds via the rotational speed. The individual integrated primary control units in each R5 PLUS communicate with each other via a higher-level secondary control unit – the PLUS Master Control. In this way, the overall performance of the vacuum system adapts precisely to the actual demand. The central vacuum system can be easily operated via the PLUS Master Control touchscreen. 

After several months of operation, it became apparent in practice that the vacuum system's control unit responds much more finely than with the previous system, which also responded to changes in demand by simply switching individual vacuum pumps on and off, but in coarser steps. The converted vacuum system can now guarantee compliance with cycle times and a precisely defined vacuum level in each individual package. The new R5 PLUS rotary vane vacuum pumps are larger than the vacuum pumps previously used. This is because in the future, even more thermoforming machines will be connected to the central vacuum supply. But the proven old R5 rotary vane vacuum pumps are not to be abandoned in the future. One or more will be used in the future on tumblers as a single unit.

About the Author
Uli Merkle is Head of Marketing Services at Busch Dienste GmbH in Germany, part of the international group of Busch Vacuum Pumps and Systems, email: uli.merkle@busch.de.

About Busch Vacuum Pumps and Systems
Busch Vacuum Pumps and Systems is one of the largest manufacturers of vacuum pumps, blowers and compressors in the world. Our products are at the forefront of vacuum and low-pressure technology. For more information, visit www.buschvacuum.com.
All photos courtesy of Busch Vacuum Pumps and Systems.

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