Flexible system meets dairy plant demands

The Lewa pumps in operation at the Arla plant
The Lewa pumps in operation at the Arla plant
Ecoflow pumps used at Arla are well-suited to the food industry
Ecoflow pumps used at Arla are well-suited to the food industry

Spreadable butter is one of the primary products of dairy company Arla. Water, rapeseed oil and brine are the key ingredients to give the butter Arla produces its flavor and spreadable consistency.

At its Swedish plant where it is producing the Bregott brand for the domestic market, ingredients must be precisely metered.

For 10 years, the production facility in Götene has used pumps from Lewa which are not only designed for high discharge pressures but are also accurate within a range of plus or minus 1%. When it came to installing new equipment, Lewa was able to configure a combination of its Ecoflow pumps which are ideal for food production.

High precision

The mixing system for the plant must meet the strictest hygienic requirements and – even more importantly – meter with high precision to guarantee consistent product quality. Ecoflow pumps are designed to be suitable for high discharge pressures and to ensure good reproducibility. About 30 of them were installed in different plants, including nine diaphragm pumps and one packed plunger pump in the facility in Götene.

In line with the modular principle, different drives were combined, each with two to six pump heads. With the Ecoflow, up to 6 m³/h per pump head can be conveyed. The discharge pressure supported can reach up to 500 bars. Depending on the application, the pressure range at Arla is up to about 1 m³/h and 15 bars.

Since the entire production facility runs at a highly automated level for both hygiene and efficiency, the pumps must be able to work nearly maintenance-free, so the manufacturing process needs to be interrupted as little as possible.

"The pumps are in operation about 20 hours a day, although not all at one time. And they have to work at a reproducible metering accuracy of plus or minus 1%,” said Klas Erikson, maintenance team leader at Arla Foods Götene.

"The strict requirements for precision and robustness that our application demands have been met by Ecoflow pumps."

Jörg Sommer, product manager at Lewa, added: "Thanks to the patented Diaphragm Protection System (DPS), used in the Ecoflow series, the diaphragm needs no positioning and the pumps can start reliably from any operating condition.”

Special technology

The result is a high level of process reliability and resilience. The special technology permits an absolute suction pressure of up to 0.1 bars.

"They keep working reliably even after operating errors or in case of extreme operating conditions, such as high suction pressure or a closed suction line," said Mr Sommer.

The pumps also have a diaphragm that can be changed quickly and easily. Automatic stroke adjustment and additional frequency control of the motor permits the large adjustment range of the pumps to be regulated reliably and the entire process can be documented. The concept is extremely well-suited for the traceability of batches and the high quality requirements in today's food industry.

"Aside from the usual standards for the food industry, we have also made sure the pumps can easily be cleaned," said Mr Erikson.

Thanks to its smooth stainless steel surfaces, the entire pump is well-suited for the food industry and for CIP cleaning. The hermetically sealed, oscillating diaphragm pumps are used where high production quality and precise recipe settings must remain consistent for years.

Operational reliability

Due to their operational reliability and the high metering accuracy, the pump is also used for toxic, environmentally harmful, abrasive, viscous, sensitive and expensive fluids. The diaphragm monitoring – in combination with the multi-layered design of the sandwich diaphragm structure – prevents any contamination of the product.

All components that come into contact with the medium are designed to be suitable for foods. When selecting the materials, Arla paid particular attention to the fact that the seals of the valves must remain elastic even after years of contact with brine.

Since salt has a corrosive effect over time, the decision was made to use Gylon, a type of Teflon. The diaphragm consists of pure Polytetrafluoroethylene, which is compatible with biological tissues.Finally, a combination of high energy efficiency, low maintenance costs and long life of the sandwich diaphragms means system costs over the course of its lifetime remain remarkably low.