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 -13°F (-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 $186 million (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, Germany, the energy efficiency module MSE6-E2M has just recently been deployed to reduce the compressed air consumption of a plant manufacturing Magnum ice creams. Unilever and Festo worked together closely to get this prototype of the energy efficiency module ready for series production. This process also showed that it is not just in the field of energy consumption that less is more.


Sustainability along the entire line

The Heppenheim factory is one of the main Unilever production locations for ice cream. These include products of the well-known Wall’s 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 on a stick per hour. This requires a lot of energy. In order to reduce the compressed air consumption of the pneumatic components, the ability to visualise and measure the 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,” says 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 other areas of the plant. Energy-intensive geared motors were replaced with more efficient ones, achieving energy savings of up to 60 per cent. Numerous 18 kW ventilators in the cooling tunnels, which previously ran for 24 hours in continuous operation, were also converted to frequency converters with variable torque loads. This lowered the energy consumption of the ventilators by around 40 per cent.


Energy consumption made visible

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,” explains Hemmerich. “In addition, we were able to determine how the compressed air requirement developed when we switched off individual consumers. We were thus able to locate leaks and eliminate unnecessary consumption.”

One of the core functions of the MSE6-E2M is the automatic shut-off of the compressed air in stand-by mode, which made it possible to establish how quickly the system empties. The energy efficiency module MSE6-E2M immediately reports an unusually quick drop in pressure to the system controller. At the same time, the automatic pressure shut-off 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 to operate the MSE6-E2M via the system controller so that all information is merged centrally.


Significantly reduced energy consumption

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 machines controller. It is easy to operate via the control panel. “We’ve been able to reduce compressed air consumption on the Magnum production system step by step with the energy efficiency module from Festo. We did not have to add any addtional communication or power cables when converting our existing systems.” On the Magnum line, the costs for compressed air consumption were reduced by more than $650 (500 euros) per year.


Concentrating on the essentials

The Magnum line at Unilever provided an ideal environment to field test the MSE6-E2M prototype. The pilot use in the Heppenheim plant and the close cooperation with Festo developers showed what daily operation would be like. While the first version of the energy efficiency module still had I/O slots, the final MSE6-E2M uses a fieldbus 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 complete series 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.


Smart Service Unit Lowers Compressed Air Energy Cost and Contributes to Improved Machine Operation

The intelligent unit automatically monitors and optimizes compressed air use by a machine and also alerts plant personnel to system leaks.


Festo MS6-E2M units can pay for themselves in less than a year from the energy savings accrued. The MS6-E2M automatically shuts off the air supply to a machine when in standby mode, thus reducing energy consumption. E2M performs typical monitoring functions, making system pressure and flow information available in real time which enables faster response to compressed air leaks. These units can send information directly to PLCs via such communication protocols as Ethernet/IP, EtherCAT, ModbusTCP, PROFINET IO, and PROFIBUS DP. 

The MS6-E2M features a solenoid valve integrated with a pressure and a flow sensor in one compact package. These units flow up to 5,000 liters of compressed air per minute.


Automatically go into standby mode to save energy

Based on user defined parameters, the MS6-E2M module detects when a machine is idle and automatically shuts off the air supply. When the unit receives a startup signal from an operator, the MS6-E2M resupplies compressed air. In the case of a particularly complex production process, automatic standby detection can be deactivated in favor of manual operation.


Automatic leakage detection

The MS6-E2M unit detects when there is a pressure drop greater than a predefined value and sends an alert about a possible leak. Higher than anticipated air flow during production also indicates possible leakage and triggers a user defined alert. Eliminating leaks not only saves energy, it also brings the compressed air system back to specification, ensuring quality operation of the machine, optimum throughput, and higher overall equipment effectiveness (OEE).


A wealth of data

The MS6-E2M actively monitors the condition of the pneumatic system in real time. This feature gives plant operations personnel access to up-to-the-minute process-related data as well as comparative data over time. Values for flow rate, air consumption, and pressure are continuously available. Data can help personnel determine historical trends on consumption, the amount of air consumed per product batch, and pressure and flow at the time of a malfunction or bad batch of product.  The MS6-E2M module is suitable for new machines and as an easy retrofit to existing machines.