Energy-saving measures are a cornerstone of the corporate philosophy of global firm Unilever. The company is now significantly reducing its compressed air consumption on a machine producing Magnum ice creams by using the new energy efficiency module MSE6-E2M.
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.
Endless production: Each one of the five Magnum lines produces more than 20,000 units per hour.
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.
The Magnum line at Unilever provided an ideal environment to field test the MSE6-E2M prototype. The pilot use in the Heppenheim plant and close cooperation with the Festo developers revealed important requirements for daily operation. While the first version of the energy efficiency module still had I/O slots, the final MSE6-E2M uses a Profibus interface. The exhaust valve of the first product generation was also dropped. It was more important to keep the energy efficiency module compact, especially given the limited installation space of existing systems. Thus the MSE6-E2M was designed on the basis of a combination of pressure and flow sensor, shut-off valve, and fieldbus node.
As a finished commercial product it is now only about half the size of the prototype and thus optimally tailored to the requirements of machine operators and builders. It makes energy monitoring simple and effective, and supports companies such as Unilever on their path to effectively increase their sustainability.
The energy efficiency module MSE6-E2M monitors and regulates the compressed air supply in new and existing systems—fully automatically. Similar to the start-stop system in a car, the intelligent MSE6-E2M detects a standby mode and automatically shuts off the supply of compressed air. Compressed air consumption is thus reduced to zero during system downtimes and breaks. In addition, the MSE6-E2M makes it possible to measure leaks by notifying the system operator if the pressure drops too quickly during downtimes. Moreover, it continuously delivers process-relevant data such as flow, pressure, and consumption, which it sends to the machine controller via Profibus.