A machining center usually needs an air compressor with a power of 7.5kW to 22kW and a displacement of 0.5m & sup3;/min to 1.2m & sup3;/min the specific selection shall be determined in combination with the gas consumption of the equipment, the simultaneous use coefficient, the leakage rate and the actual working conditions. The following is a specific analysis:
calculation basis of core parameters
- exhaust pressure: The rated pressure of pneumatic actuators in the machining center is 0.6-0.7MPa(6-7bar), and the pipeline pressure loss (0.01-0.02MPa/100 m) and allowance (0.05MPa) should be considered. For example, when the workshop pipeline is 200 meters long, the selection pressure is 0.6+0.04+0.05=0.69MPa, and the 0.7MPa standard model is preferred.
- Exhaust volume: The air consumption of a single processing center is usually 0.3-1.2m & sup3;/min, the total demand should be multiplied by the simultaneous use coefficient (0.7-0.9) and leakage rate (15%-20%), and 10%-20% margin should be reserved. For example, 10 sets of gas consumption 0.5m & sup3;/min processing center, the total demand is 10 × 0.5 × 0.8 × 1.18=4.72m & sup3;/min, it is recommended to choose 5-6m & sup3;/min model.
Typical Configuration Scheme
- small shop (1-3 machining centers): Recommend 7.5-22kW permanent magnet frequency conversion single-stage screw machine with 1m & sup3; Small gas storage tank and three-stage filtration system meet the demand for intermittent gas consumption with small pressure fluctuation.
- Medium-sized intershop (4-10 machining centers): 37-75kW permanent magnet frequency conversion two-stage screw machine is recommended, equipped with 3-5m & sup3; Air storage tank and cold dryer support multi-machine linkage and comprehensive energy saving of 50%.
- Precision machining center: ISO 8573-1 Class 0 oil-free screw machine is required, with precision filter and adsorption dryer to ensure that the oil content of compressed air approaches zero.
Key considerations for selection
- avoid false standard of theoretical displacement: The supplier is required to provide a measured flow report under actual working conditions (target pressure + ambient temperature) to prevent the purchase of equipment with insufficient displacement.
- Priority permanent magnet variable frequency drive more than 30% energy saving compared with power frequency models, especially in low load conditions (such as single operation at night), the energy saving effect is remarkable, and the pressure fluctuation can be controlled within ± 0.1bar.
- Select the cooling method as required: Air-cooled type is recommended for single machine power ≤ 75kW, and water-cooled type is recommended for ambient temperature> 45 ℃ or multi-machine centralized air supply, with higher cooling efficiency and lower noise.
