Cooling Systems for Die Casting and Metal Injection Processes

Calculate loads from moulds, temperature controllers, hydraulic systems, induction equipment and auxiliary circuits separately. Review machine-maker data, cycle times and the number of machines operating together. For an existing plant, calculate actual load from measured flow and inlet-to-outlet temperature difference.

A preliminary estimate uses casting throughput: about 800 kJ/kg for aluminium and 200 kJ/kg for zinc alloy. A machine casting 150 kg of aluminium per hour has a mould load near 33 kW; add hydraulic-oil cooling, typically 10–20% of installed hydraulic power, and the controller load. Confirm capacity from machine-maker data or plant flow and temperature measurements.

There is no single value for every casting process. Direct water-cooled mould circuits often run at 15–30 °C, while moulds supplied through temperature controllers may run at 60 °C or above. Choose the temperature for the metal, part geometry, mould material, channels, cycle time and solidification target. Water that is too cold risks thermal shock; too hot can lengthen cycles.

Yes. The controller holds the mould at its set temperature but transfers excess mould heat to process water through its cooling exchanger. A chiller or dry cooler must then reject that heat. Include the controller maker’s cooling-side water temperature and flow requirements in plant sizing.

The bottleneck is often flow or heat transfer rather than cooling capacity. Blocked mould channels, trapped air, poor balancing, low pump pressure or a fouled exchanger can all limit cooling. Measure flow, pressure difference and inlet and outlet temperatures in each mould circuit before increasing chiller size.

It is technically possible, but open-loop water carries sediment, corrosion products and biological contamination. Narrow channels can lose flow and heat-transfer performance. Separating sensitive circuits with a heat exchanger and a closed, treated-water loop gives better control.

Induction-coil and power-unit circuits commonly need 25–35 °C inlet water and no more than 50–60 °C return water. They typically circulate deionised or demineralised water below 50 µS/cm conductivity in a separate closed loop. Confirm the exact limits with the furnace manufacturer.

It temporarily balances cyclical peak loads against chiller capacity and reduces frequent compressor starts and stops at low load. Size the tank from peak load, chiller capacity, peak duration and allowable water-temperature change.

Compare supply and return flows, monitor tank level and make-up water, track circuit pressures and add leak detection in critical areas. Set alarms and machine-stop sequences to match the casting-machine maker’s safety requirements and the facility risk assessment.

Savings depend on process-water temperature, location, operating hours and weather. Hydraulic-oil and auxiliary circuits at 35–45 °C may use dry coolers for much of the year; separating them from mould cooling can reduce required compressor capacity by 30–50% in many plants. Calculate actual benefit from hourly weather and load data.

Critical induction-cooling circuits can use standby pumps, independent power and control monitoring, low-flow alarms, buffer volume and, where needed, N+1 chillers. Integrate the safe-stop sequence with machine controls according to the equipment maker’s requirements.