Challenge
A mass producer of plastic decorative ornaments for car interiors needed a heat rejection solution to ensure adequate cooling capacity during the injection moulding manufacturing process. This is a particular challenge in summer when ambient temperatures are high and the company’s existing free cooling system isn’t sufficient.
The injection moulding process obtains moulded products by shaping liquids – or malleable raw material such as metal, plastic or glass – in a fixed frame known as a mould or matrix and typically consists of a three-step process. Firstly, the malleable raw material is heated and injected under very high pressure into a closed metal mould tool. Then the molten material needs to cool down and harden before being removed. For this customer, the products need to cool down to between 32°C and 35°C before being ejected from the mould tool and delivered to secondary operations. The customer’s injection moulding machines have a built-in, water-cooled heat exchanger which is hydraulically connected to the centralized cooling system and heat rejection is provided through this centralised system.
Solution
The local Trane Rental Services team recommended the use of a DRY500 dry cooler. Dry cool units utilise air to regulate process temperature and consist of a system of tubes or fins that allow refrigerant to flow through them. As air is blown over the surface of the tubes or fins, the heat from the refrigerant is transferred to the air, and the refrigerant is then returned to the system to absorb more heat.
Trane’s DRY500 is capable of 500Kw of cooling capacity under standard conditions and, to ensure the required cooling effect during the summer peaks, a Trane Rental Adiabatic cooling system was also added. Analysis of the adiabatic effect during summer climatic conditions (both temperature and relative humidity) determined that the only solution to deal with climate peaks would be the provision of a dry cooler.
The Trane Rental system now augments the customer’s existing free cooling system to provide increased cooling capacity, serving half of the production machines at the site.
Results
The customer was delighted with the Trane Rental solution. Adiabatic pre-cooling is provided by Trane, a unique UV-resistant mesh and water spray that optimises the performance of air-cooled chillers, dry coolers and refrigeration plants while drastically reducing energy consumption. In addition, the coils of the cooling equipment are protected as the water spraying of the adiabatic cooling system is in counterflow with the forced air circulation of the coolers.
Trane Rental also supplied the customer with a high-pressure head circulation pump kit and hoses. This hydraulic module comes with a full electric control panel and hydraulic balancing accessories. A Freeze Protection Module was also in operation over the winter period. This antifreeze equipment ensures that should freezing conditions occur, all outdoor installations are insulated from the factory’s hydraulic circuit.
The customer took advantage of a Trane EaaSy contract for the rental period. EaaSy stands for “Equipment-as-a-Service” and it’s a Trane Rental formula that provides a host of stand-out benefits for customers including ongoing maintenance and 24/7 service support. Full training was also supplied along with connection to the customer’s existing system.
