Total Cost of Ownership costs minimized - profits increased

The Whey V project of Sachsenmilch in Leppersdorf has recently started using hygienic high-efficiency centrifugal pumps from Packo

High-efficiency pumps are high in demand for filtration systems in the dairy industry. A continuous operation and large volumes to be pumped require "workhorses" whose number of suppliers can be counted on the fingers of one hand. Designing centrifugal pumps with a high capacity, both hygienically and as energy-saving as possible, is a real challenge.

Sachsenmilch Leppersdorf GmbH, which was acquired by the Theo Müller group in 1994, is today regarded as one of the biggest and most modern dairy companies in Europe. Every year, around 2,600 employees process more than 1.8 billion kilograms of raw milk into a wide variety of products such as UHT milk, milk powder, butter, cheese or whey derivatives. Since the takeover in 1994, the site has been constantly expanded and modernized, and a total of more than 1 billion euros has been invested.

A considerable amount was invested in the construction of buildings and equipment for the processing of whey, where currently around 160 people are working. Since 2002, this independent business unit has been set up in four steps called Whey II to V. The whey V section, which came into use in April 2016, is also responsible for the production of lactose according to the Dry Mix standard for use in the baby food industry.

All expansion phases have in common - and this is especially true for whey V - that not only the garantuee of the highest hygiene standards has the highest priority, but also aspects of energy efficiency play an important role in the use of modern mechanical equipment. This includes the choice of the right pumping equipment, which must fulfil a wide variety of tasks in production.

Ideal collaboration

VA GmbH, member of the Kieselmann Group, could be attracted as an optimal partner with regard to filtration and process technology. The company, headquartered in Stuttgart and with an assembly centre in Heilbronn, specializes in the planning and installation of process installations for the food and dairy industry and supplied various membrane filtration plants for the total whey project V.

After a short time, the performance of the pumps in operation was put to the test and alternatives were sought in this capacity range. The choice fell on the centrifugal pumps from Packo Pumps. As a result, our German distributor Koch Pumpentechnik was responsible for the technical advice and the organizational handling and, as an executive body, supervised the conversion on site.

Based on the consideration that centrifugal pumps for filtration applications are used almost 365 days per year and in 24-hour operation at Sachsenmilch, high efficiency, lower operating costs and less maintenance work were important factors in the decision-making process. Three years ago, to begin with, one of the 16 pumps equipped with 110 kW motor on one of the ultrafiltration systems was replaced as a trial by a Packo Pumps MFP3 series stainless steel centrifugal pump. The four-month test produced amazing results in several respects.

Optimized flow mechanics due to volute construction

An important goal was to achieve an increased efficiency, since the replaced pump has a welded construction which is not optimal for the efficiency. The MFP3, on the other hand, is equipped with an efficiency-increasing 316L cast stainless steel pump casing and a hygienic closed cast impeller made of stainless steel.

Packo Pumps is one of the few manufacturers of hygienic centrifugal pumps that meet or even exceed the high technical requirements of the European Regulation No. 547/2012 MEI (Minimum Efficiency Index, actually prescribed for water pumps). These excellent efficiencies for centrifugal pumps are made possible by the optimization of the design of the pump casing and the impellers using advanced flow simulation programs. The improvement of the flow behaviour is mainly achieved by a volute construction of the pump casings, which ultimately can only be achieved by casting.

Decreasing energy consumption

Thanks to the higher efficiency of more than 80 percent in some cases, the energy consumption is significantly reduced. The energy savings that were established in practice thus became the decisive criterion. These are in the order of about 15 to 20 percent. In this specific case, the type MFP3 / 150-315 / 9004 (C-360) was used with a four-pole motor of 90 kW. With this power the pump appeared to be almost overdimensioned. With a real power consumption of 70 kW, the 75 kW model of the series could have been sufficient as well. The series also include versions with a motor output of up to 250 kW and a maximum flow of 1,200 m³/h - in the industrial version up to 1,800 m³/h.

Another positive effect of the high efficiency is the very gentle pumping of the media. It was also determined that the Packo pump works much quieter than the previous model.

Low maintenance costs

An additional advantage is the considerably lower maintenance costs. In the past, for example, the mechanical seals had to be replaced once a year, but the Packo pumps have been running smoothly with the first sealing set for almost two years now. Not only are they particularly low-maintenance in this respect, but they also significantly reduce annual revision costs.

The successfully completed test run resulted in a considerable order at Koch Pumpentechnik and respectively Packo Pumps, for a total of 16 MFP3 pumps, which were installed in the filtration systems in 2016. In addition, another 54 centrifugal pumps, also exclusively produced in hygienic design, are installed in the periphery, for example for supply from the tanks. With capacities between 1.1 and 90 kW they reflect the wide reach of the Packo range.

Positive practical experience

Michael Kühn, Head of Technical Projects at Sachsenmilch Leppersdorf GmbH, assesses the new pump installation in great detail and in a practical way, building on more than 30 years of professional experience. His experience so far is extremely positive: "for me as a process engineer, the flow optimization achieved by the special volute design and the resulting energy savings are decisive. In terms of the absorbed power that we are talking about here, differences in motorization already play an important role. Profit in energy consumption can only be achieved by minimizing the loss in the pump itself and that is a matter of flow optimization.

This has become clear to us during a visit to the Belgian factory in a very illustrative way. We had the opportunity to look over the shoulders of the Packo engineers and learn that pumps are first tested by software before they go into the casting production. For example, we could assume that they are selected for the respective application and work at their optimum point. The figures on paper have proven themselves. In practice, we were able to demonstrate the promised energy savings in the order of 15 to 20 percent very quickly and clearly.

He is also satisfied with the low maintenance costs of the pumps, which are regularly maintained preventively. "We have noticed that such a pump does not have to be opened every three months. An additional advantage is that Packo Inox only uses standard parts for all series ".

Michael Kühn is also satisfied with the organizational completion of the conversion: "The whole, fairly extensive installation went smoothly, even though we used completely new pumps."

Extensive follow-up order

In the perspective of this extremely positive assessment, it is not surprising that Koch Pumpentechnik received an extensive follow-up order for Sachsenmilch from VA GmbH in December 2017. It concerns a microfiltration installation equipped with seven MFP3 pumps. Some of these are types with 200 kW motors and maximum flow rates up to 1,800 m³/h, making them even more powerful than the above-mentioned models. In addition, 36 units were installed for further projects - starting from an engine power of 3 kW - and 20 additional Packo centrifugal pumps were set up in the periphery.

Packo Pumps is just one of the partners with whom Koch Pumpentechnik has been implementing similar projects for years. Partner companies of the in 1980 founded specialist in Porta Westfalica are also Ytron Process Technology and Pumpenfabrik Wangen. In addition, pumps that are universally applicable in many areas are built under their own name, for example in process engineering, for washing slops - in particular dirty water -, animal feed, liquid fertilizers or oils and coolants.

As CEO of the North-East Westphalian company, which has branches in Ellerbek near Hamburg, Nuremberg and Leipzig, Uwe Koch sees the company as problem solver that goes beyond just sales. 
This also includes extensive advice on large-scale projects and technically advanced process installations, for example when problematic or sensitive media needs to be pumped.

Bernd Neumann