Reobijn is saving around 10% a year on its total energy bill with a new, future-proof cooling system from ONI Wärmetrafo & Plastima.
The combination of free cooling, frequency control and waste heat recovery cuts consumption and makes the installation ready for further growth of the machine park.
Reobijn specialises in the injection moulding of technical plastic components and is increasingly committed to more sustainable materials, including recycled and biobased plastics. That kind of operation also calls for close attention to the energy consumption of the production process, and process cooling is one of the larger items.
Reobijn’s existing cooling system was approaching the end of its service life, while there were plans to further expand the number of injection moulding machines. Additional energy savings and production reliability were therefore the main drivers behind the decision to invest in a new installation.
“We built this to be prepared for the future.”
Chris Visschedijk, Purchasing Manager and responsible for the cooling system at Reobijn
The new system comprises two separate cooling circuits. The hydraulic circuit is cooled entirely by free cooling; the free coolers run on 100% water, without glycol. The mould circuit is served by both a chiller and a free cooler: as soon as the outside temperature is low enough, the free cooler takes over the role of the compressor in the chiller. At those times this delivers up to 90% energy savings compared with compressor cooling.
Thanks to this combination of free and mechanical cooling, the installation runs as efficiently as possible for a large part of the year. The chiller and free coolers are placed on the roof, while the technical installation is housed indoors.
According to Reobijn, the energy consumption of the entire plant has fallen by around 10% on an annual basis compared with the old cooling system. The biggest contribution comes from the efficient use of the free coolers for hydraulic and mould cooling. In addition, frequency-controlled pumps match the output to the actual cooling demand, and ONI’s advice to raise the temperature of the hydraulic circuit contributed further: it extends the range in which free cooling can be used.
The energy efficiency goes beyond limiting electricity consumption alone. The heat extracted from the hydraulic circuit is reused within the plant: several departments are heated with it, and part of the underfloor heating also runs on this heat.
Beforehand, Reobijn had some doubts as to whether the available waste heat and the relatively small-looking heating units would be sufficient to actually heat the rooms. In practice it has proven to be a sound solution that fully heats the various departments. Energy that would otherwise be lost as waste heat is thus put to use again within the production facility.
Before making the investment, Reobijn approached several suppliers. ONI and Plastima had already supplied a cooling system to Reobijn’s sister company Final Plastics, and through that relationship ONI also came into the picture at Reobijn. In the preparatory discussions, ONI convincingly demonstrated its relevant experience with cooling systems for plastics processing, which played an important role in the final choice.
Reobijn is now very satisfied with the installation as well as the support, execution and service. Chris Visschedijk describes the ONI engineers as true professionals who know what they are doing.
The new cooling system gives Reobijn more than reliable process water cooling. Free cooling, frequency control, energy-efficient components and waste heat recovery limit consumption, while the design takes the future growth of the machine park into account.
That is precisely the focus of Plastima and ONI in projects like these: not just supplying a cooling system, but looking together with the customer at the total cooling demand, energy efficiency and future developments in the production process — and providing the right advice along the way.
Plastima and ONI Wärmetrafo thank Reobijn for the confidence placed in them and look forward to continuing the collaboration.
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