Refrigeration in the Metalworking Industry: Machining and Heat Treatment
The metalworking industry relies heavily on refrigeration systems to ensure dimensional accuracy, surface quality, and tool life. From CNC machining centers to heat treatment furnaces, temperature control is critical.
Refrigeration Applications in Metalworking
Cutting Fluid Refrigeration
The cutting fluid (soluble or synthetic oil) heats up during machining. Keeping its temperature controlled is essential for:
- Dimensional stability of the parts
- Tool life
- Surface finish quality
- Operator health (mist reduction)
Spindle Refrigeration
High-speed spindles generate significant heat. Inadequate cooling causes:
- Thermal expansion and loss of precision
- Premature bearing wear
- Unscheduled downtime
Heat Treatment
Processes such as quenching, tempering, and carburizing require precise temperature control to achieve the desired metallurgical properties.
Typical Process Temperatures
| Application | Temperature | Precision |
|---|---|---|
| Cutting fluid | 18°C to 22°C | ±2°C |
| Spindle cooling | 20°C to 25°C | ±1°C |
| Oil quenching | 40°C to 80°C | ±5°C |
| Polymer quenching | 25°C to 40°C | ±2°C |
| Precision grinding | 20°C ±0.5°C | ±0.5°C |
Helioterm Solutions for Metalworking
Chillers for Cutting Fluid
- Capacities from 1 to 50 TR
- Stainless steel evaporators (resistance to cutting fluid)
- Easy-to-clean filters
- Precise temperature control
Thermoregulators
For applications requiring heating and cooling:
- Temperature range from 5°C to 150°C
- Control of ±0.5°C
- High-pressure pump for long circuits
Chillers for Heat Treatment
- High cooling capacity
- Resistance to high return temperatures
- Materials compatible with quenching oils
Success Story: Auto Parts Manufacturer
An auto parts industry with 15 CNC machining centers was facing problems with dimensional variation in parts and high tool consumption.
Diagnosis:
- Cutting fluid temperature varying from 25°C to 38°C
- Each machine with an individual cooling system (adapted splits)
- Dimensional variation of ±0.05mm (specification: ±0.02mm)
- Tool change 40% above the forecast
Solution implemented:
- Chilled water plant with 2 Helioterm 20 TR chillers
- Distribution network with manifold
- Individual heat exchangers per machine
- Temperature monitoring system
Results:
- Fluid temperature stabilized at 20°C ±1°C
- Dimensional variation reduced to ±0.015mm
- Tool life increased by 60%
- Scrap reduction from 4.5% to 0.8%
- ROI in 10 months
Sizing Chillers for Machining
To correctly size a chiller for machining, consider:
- Machine power: Approximately 30% of the main motor power is converted into heat in the fluid
- Type of operation: Roughing generates more heat than finishing
- Material being machined: Hard materials generate more heat
- Ambient temperature: Hotter locations require greater capacity
Rule of thumb: 1 TR of refrigeration for every 10 to 15 kW of installed machine power.
Conclusion
Proper refrigeration in the metalworking industry is an investment in quality and productivity. Centralized systems offer better control, lower operating costs, and greater reliability than improvised solutions.
Helioterm serves metalworking industries of all sizes, with solutions ranging from compact chillers to large-capacity chilled water plants.