Dynamic growth needs a solid basis. Therefore, when it comes to their current expansion of production facilities, AZ Ausrüstung und Zubehör GmbH & Co. KG from Hattingen, a company of the Vollmann Group, rely on Reisner cooling technology. From now on, a new and fully equipped system featuring pioneering energy saving technology provides the necessary cooling performance: a safe and efficient solution, already prepared for the automotive supplier's further expansions.

Since 2017, AZ Ausrüstung und Zubehör GmbH & Co. KG is geared for growth. The company produces high-quality fastening components and accessory parts for motor vehicles, mostly using injection moulding technology. Due to their very positive order situation they launched an extensive conversion project. Thomas Ostkamp, plant manager for the automotive supplier, kicked it off in December 2017. "At first, we had to create a viable basis for our expansion", he recalls. "We needed several new injection moulding machines and subsequently a lot more cooling performance. For many years we had been working with a Reisner cooling system much to our satisfaction, so we decided to request Reisner Cooling Solutions GmbH for a quotation about the new system. Our priorities were set on absolute reliability, high energy efficiency and maximum flexibility. The Reisner concept convinced us in all regards."

Fully equipped, flexible and mobile
To cover the newly determined need of 160 kW in tool cooling and 200 kW in hydraulics cooling, Reisner Cooling Solutions GmbH combined a state-of-the-art screw compressor cooling machine with two dry coolers. They attached a custom-made tank system featuring pumps and cooling water treatment technology. While the existing cooling system was positioned within the production area, building space had become scarce in the meantime. The Reisner solution: They placed the complete system including plate heat exchangers and control cabinet inside a container, 12 metres long and 2.45 metres wide. Condenser and dry coolers were installed on the container roof. In case of extreme summer temperatures, the dry cooler can be sprayed with water - the so called "adiabatic cooling" helps to absorb peak loads.

Within the production hall, Reisner installed a sophisticated cooling water circulation system right below the ceiling. It is completely constructed of corrosion-free materials and leads through the whole production area so that all injection moulding machines are supplied with cooling water. The individually programmed PLC guarantees a smooth operation. It controls the new system components as well as the existing cooling unit which was integrated to add to the operational safety as a part redundancy. Using the touch panel of the control unit inside the container and a second panel in the production area, the AZ technicians can read off all operating states intuitively and handle the system comfortably.

More performance, less consumption
The sophisticated control is crucial to gaining the necessary cooling performance without raising the energy consumption level proportionally. On the contrary: "Our energy management is certified according to DIN EN ISO 50001", explains Michael Lohmann, head of project management and production technology on the Hattingen site. "With our high-energy production, this is an important key to reducing operational costs. Our aim was to increase the output significantly without having energy consumption rates explode. This is why we imposed high demands on the new cooling technology's energy efficiency. The intelligent Reisner solution combines three energy saving features that help us keep our operational costs on a low level."

Aside from the pre-cooling of the refrigerant known as "ECO", the most effective way of reducing energy consumption Reisner Cooling Solutions use is the so called Vario technology. Thomas Imenkämper, CEO and sales manager, explains: "With Reisner Vario we adapt the condensation temperature of our cooling system to the actual ambient temperature. As the outside temperature declines, we need less compressor performance for the necessary cooling results. Consequently, energy consumption and operational costs decrease. The dry coolers save energy as well with cooler outside temperatures. One of the dry coolers can be used as a winter relief. This operational mode, also known as "free cooling", gradually turns down the cooling machine and has the cooling performance provided for by the dry cooler, so that in the maximum stage of winter relief the compressor's consumption is lowered to zero.

The new cooling system's consumption values impressively illustrate this Reisner effect. While a regular 160 kW cooling system without Reisner energy saving technologies would consume 258,760 kWh per year, the Vario equipment already reduces this consumption to 160.850 kWh. As Reisner also installed the winter relief, this rate is once again drastically lowered. In the end, the whole cooling system operates on 66,183 kWh per year only, proving that the Reisner energy saving equipment reduces the energy consumption by a full 75%.

Clean and safe, for years to come
The influence of the cooling water quality on energy consumption is often underrated. Reisner Cooling Solutions have taken this into account and installed their complete water treatment equipment in the AZ container. In the first step, a full-stream reverse flow filtration system consisting of stainless steel filter baskets frees the cooling water of solids. Michael Lohmann appreciates this filtration concept: "The filter works without pressure, and a build-up of backwater is avoided. Even if the filter inserts are blocked, the water can flow back to the tank. Production continues, and no interruptions are necessary for clearing the filters. A perfectly balanced dosing of corrosion inhibitor and biocide prevents rusting and infestation by algae. This protects the heat exchangers as well as the expensive tools AZ uses for injection moulding.

A further plus for operational safety: Reisner service technicians will tend to the system on a long-term basis with preventive maintenance. In case of a malfunction, they are always close at hand. "The Reisner team enabled us to contribute to the maintenance of the system ourselves by giving us detailed instructions shortly after commissioning", reports Michael Lohmann. "Now we are well-trained in the operation of and care for our system." With the help of a special signalling system and a second control panel inside the production hall his staff can constantly keep an eye on the system status without leaving the building.

Fit for the future
All these details were drawn together by Thomas Imenkämper and his team in close collaboration with AZ. This way they perfectly adapted the system to the current and upcoming requirements of the operating company. Michael Lohmann is content with the outcome, but also with the process. "The 3D visualizations we regularly received showed us that the works proceeded exactly as we had planned. Within the container, all components are arranged neatly and they are perfectly accessible for maintenance and repair. The pipework was also carried out accurately. Planned with a view to the future, it keeps us all options open for further expansion." With their choice of refrigerant, Reisner Cooling Solutions proved their future orientation as well: R513a has a low GWP and will be available at reasonable prices for years to come. "The system is up and running, upcoming additional requirements are taken care of, and if we want to reorganize our production we can reposition the container at the blink of an eye", Hattingen plant manager Thomas Ostkamp summarises, "with Reisner technology we are perfectly prepared for further growth".