What is the charging capacity of the medium pressure air compressor

Analysis of filling capacity of medium pressure air compressor

The filling capacity of a medium pressure air compressor is one of the core indicators to measure its performance, which is directly related to the air supply efficiency and application scenarios of the equipment. The following is explained from four aspects: technical definition, performance, influencing factors and selection suggestions to help enterprises scientifically understand the filling capacity of medium pressure air compressors.

1. Technical definition of medium pressure air compressor

1. Pressure range definition
   • Medium pressure air compressors usually refer to equipment with discharge pressures between 1.0MPa and 10.0MPa (10bar to 100bar).
   • comparative statement: Low-pressure models (≤1.0MPa) are suitable for general pneumatic tools, and high-pressure models (≥10.0MPa) are mostly used in special industrial fields.
2. Core parameters of refueling capacity
   • exhaust volume: Volume of gas output per unit of time, in cubic meters per minute (m³/min) or cubic feet per minute (CFM).
   • fill rate: The time required to charge the air storage tank from low pressure to rated pressure reflects the short-term air supply capacity of the equipment.

2. Performance of intermediate-pressure air compressor

1. Dynamic relationship between flow and pressure
   • theoretical rule: According to the gas state equation, when the temperature is constant, an increase in pressure will cause the volume of the gas to shrink. However, medium pressure air compressors can increase the pressure while maintaining a high flow rate through multi-stage compression design.
   • actual performance: At a pressure of 4.0MPa, the displacement volume of a certain medium pressure screw air compressor can reach 5.0m³/min; when the pressure rises to 8.0MPa, the displacement volume may drop to 3.5m³/min.
2. Gas filling efficiency case
   • scene simulation: Charge 1 cubic meter gas storage tank (initial pressure 0.5MPa) to 8.0MPa.
   • efficiency comparison：
     • Medium pressure piston air compressor: It takes about 15 minutes, and the filling rate is 0.067m³/min·MPa.
     • Medium pressure screw air compressor: It takes about 12 minutes, and the gas filling rate is 0.083m³/min·MPa.

3. Factors affecting refueling capacity

1. Differences in equipment structure
   • piston type: By compressing gas through reciprocating motion, the gas filling capacity decreases significantly with the increase of pressure, but the initial gas filling rate is fast.
   • screw: Using continuous rotary compression, the pressure-flow curve is smoother, suitable for scenarios requiring stable gas supply.
   • centrifugal: The efficiency attenuation is obvious under high-pressure conditions, and it is mostly used in large-flow, medium and low pressure scenarios.
2. Power and cooling systems
   • motor power: The higher the power, the stronger the driving capacity and the higher the filling rate. For example, a 30 kW motor-driven model fills 20%-30% faster than a 22 kW model.
   • cooling method: Water-cooled models have high heat dissipation efficiency and can operate continuously at high load; air-cooled models are prone to overheating and load drop in high temperature environments.
3. Pipeline and air storage tank design
   • tubing diameters: Too small diameter increases airflow resistance and prolongs filling time. For example, increasing the pipe diameter from DN25 to DN40 can reduce pressure losses by approximately 40%.
   • Air storage tank capacity: The larger the capacity, the longer the intermittent operation time of the equipment, but the initial refueling time increases accordingly.

4. Selection suggestions and application scenarios

1. Key considerations for selection
   • pressure demand: Select the model according to the rated pressure of the gas equipment, and reserve a pressure margin of 10%-20%.
   • flow demand: Calculate the total flow demand of gas equipment and select a model with matching exhaust volume.
   • environmental adaptability: Water-cooled models need to be preferred for high temperature and high humidity environments; integrated design is optional for space-limited scenarios.
2. typical application scenarios
   • industrial manufacturing: Provide high-pressure air source for CNC machine tools and laser cutting machines. The pressure requirement is usually 4.0-8.0MPa.
   • petrochemical: To drive valves and actuators, explosion-proof design models are required, and the pressure requirement is 6.0-10.0MPa.
   • scientific research experiment: Provide pure high-pressure gas source for gas chromatographs and mass spectrometers, and require supporting post-processing equipment.

V. Summary

The filling capacity of medium pressure air compressors is affected by multiple factors such as equipment structure, power configuration, cooling method and pipeline design. When selecting models, enterprises need to combine comprehensive assessments of pressure requirements, flow requirements and environmental conditions, give priority to models with high energy efficiency and strong stability, and improve overall gas supply efficiency by optimizing pipeline and gas storage tank design.