Ice cream is refreshing and with its proteins and carbohydrates is considered a source of energy. However, it also takes a lot of energy to mix ingredients like milk, dairy chocolate, sugar, and vanilla beans into the finished product. Electricity and compressed air play an important role in the thermal and kinetic processes for everything from mixing and extruding the ingredients, deep-freezing to -25°C, dipping into various chocolate coatings, through to final packaging. Energy efficiency is therefore right at the top of Unilever's list of priorities. As part of the Unilever Sustainable Living Plan, this global corporation has succeeded in saving more than 150 million euros in energy costs from efficiency improvements in production alone since 2008.
In the area of pneumatics too, the use of innovative developments offers the potential to save energy and thereby lower costs. In the Unilever plant in Heppenheim, the energy efficiency module MSE6-E2M has recently been deployed to reduce the compressed air consumption of a system manufacturing Magnum ice creams. Unilever and Festo worked together closely to get this prototype of the energy efficiency module to the production stage. This process also showed that it is not just in the field of energy consumption that less is more.
The Heppenheim factory is one of Unilever's main production locations for ice cream. These include well-known products from the Heartbrand line, including Magnum, Feast, Viennetta, and Carte d'Or. High production quantities form the basis for supplying other parts of the European market. Just one of the five Magnum production lines in Heppenheim produces more than 20,000 ice creams per hour. This requires a lot of energy. In order to reduce the compressed air consumption of the pneumatic components, the ability to visualize and measure compressed air consumption was of huge importance to Unilever. Previously, the consumption on the individual production lines had not been determined. “Until then we were just unaware,” said Alexander Hemmerich, Automation Engineer at the Unilever Plant, Heppenheim.“Air is not visible, so it is not immediately obvious if consumption is too high.”As part of the Unilever Sustainable Living Plan there had already been successes in the plant in other areas. Energy-intensive geared motors were replaced with more efficient ones, achieving energy savings of up to 60 percent. Also, numerous 18 kW ventilators in the cooling tunnels, which previously ran for 24 hours in continuous operation, were converted to frequency converters with quadratic torque. This lowered the energy consumption of the ventilators by around 40 percent.
Hemmerich and his team took the decisive step towards lowering compressed air consumption with the introduction of the energy efficiency module MSE6-E2M from Festo. “The energy efficiency module gave us the opportunity to see the amount of compressed air we were using during operation of a line,” explained Hemmerich. “In addition, we were able to determine how the compressed air requirement changed when we switched off individual consumers. We were thus able to locate leaks and eliminate unnecessary consumption.”Automatic shutoff of the compressed air in the standby mode of the MSE6-E2M made it possible to establish how quickly the system empties. The energy efficiency module MSE6-E2M immediately reports any unusually quick pressure drop to the system controller.
At the same time, the automatic pressure shutoff function prevents further compressed air consumption while the system is not in operation. Thanks to its onboard intelligence and the specific model for operating the compressed air systems, the MSE6-E2M independently identifies when a system is in production and when it is at standstill. At Unilever, however, they decided to use the alternative option of operating the MSE6-E2M via the system controller so that all information was merged centrally.
Thanks to the new condition monitoring for the pneumatic components of his Magnum machine, Alexander Hemmerich now has continuous process-relevant data. The MSE6-E2M regularly exchanges important measurement parameters, such as flow, pressure, and consumption, with the machine controller via Profibus. It is easy to operate via the control panel. “The Festo energy efficiency module has enabled us to reduce our air consumption on the Magnum production line step by step. And the Profibus connection has the advantage that we don't have to add any more cables when converting our existing systems.”On the Magnum line, the costs for compressed air consumption were reduced by more than 500 euros per year.
Heppenheim Plant
Langnesestrasse 1
64646 Heppenheim
Area of business: Production of Heartbrand ice cream