How to choose air compressor according to air consumption

The selection of air compressor according to air consumption is a comprehensive decision-making process, which needs to be combined with factors such as air demand, pressure requirements, equipment characteristics and future expansibility. The following is a detailed selection guide:

1. core selection principle

1. gas volume matching

• calculation formula:

gas demand = total gas consumption of equipment x service time x service factor (1.1-1.2)

• allowance Reservation:

• basic margin: 10%-20% (to cope with peak gas consumption or future expansion).

• Long distance air supply: increase to 20%-30% (compensate for line pressure loss).

• Example: If the total gas consumption of the equipment is 100m & sup3;/min, the use time is 8 hours, and 20% allowance is reserved, then the required gas volume is:

100×8×1.2=960m³/h

2. pressure adaptation

• pressure classification:
• low pressure equipment (such as spraying and purging):5-7bar.
• Medium-pressure equipment (such as machine tools, pneumatic tools):7-10bar.
• High pressure equipment (such as laser cutting): above 16bar.
• Allowance Reservation: The rated pressure of the air compressor should be 0.1-0.2MPa higher than the maximum air pressure.

3. Energy efficiency priority

• specific power selection:
• level 1 energy efficiency (international advanced):≤ 5.5kW/(m & sup3;/min).
• Secondary energy efficiency (more energy saving):5.5-6.5kW/(m & sup3;/min).
• Tertiary energy efficiency (normal):≥ 6.5kW/(m & sup3;/min).

2. selection calculation method

1. predictive gas consumption method

• steps:
• statistics of all gas equipment rated gas consumption, working time and load rate.
• Calculate the average gas consumption and peak gas consumption.
• Select air compressor capacity according to peak demand (reserve 10%-20% margin).

2. demand side analysis method

• steps:
• monitor the actual gas consumption curve of the equipment and identify the peak demand.
• Calculate the total demand for gas in conjunction with future expansion plans.
• Select multiple small displacement air compressors in parallel, start and stop on demand to save energy.

3. compression ratio method

• formula:

air compressor capacity = average gas consumption × (compression ratio +1)

• example: If you need to provide 7bar air pressure, select 8bar air compressor (compression ratio 1.14), then:

air compressor capacity = 100m & sup3;/min×(1.14+1)= 214m & sup3;/min

4. air system comprehensive analysis method

• steps:
• evaluate the influence of pipe length, pipe diameter and number of elbows on pressure loss (pipe loss per 100 m & asynp; 0.05MPa).
• Combined with the gas characteristics of the equipment, the total gas demand of the system is calculated.

3. Key Configuration Choices

1. control mode

• frequency conversion control: It is suitable for scenes with large gas consumption fluctuation (such as 60%-100 load), with remarkable energy saving effect.
• power frequency control: Suitable for scenarios with stable gas consumption, low cost but low energy efficiency.
• multi-machine joint control: Dispatch multiple air compressors through the central controller to balance the load and extend the life of the equipment.

2. Post-processing equipment

• dryer cold dryer (-40 ℃ dew point) or suction dryer (-70 ℃ dew point) is selected according to the gas quality.
• Filter: Three-stage filtration (coarse effect + high efficiency + super high efficiency) to ensure the cleanliness of compressed air.

3. Gas tank

• capacity calculation:

tank capacity = air compressor displacement × unloading time

• example: air compressor displacement 20m & sup3;/min, unloading time 5 minutes, then:

gas tank capacity = 20 × 5 = 100L

4. considerations

1. security:

• select equipment equipped with safety valve, overload protection, temperature monitoring and other devices.

2. Environment adaptation:

• ventilation: Ensure that the installation location is well ventilated to avoid equipment failure caused by high temperature.
• Noise: Select low noise model (≤ 75dB) or install sound insulation cover.

3. Extensibility:

• preferred modular design for future expansion.

4. After-sales service:

• choose well-known brands to ensure spare parts supply and timely maintenance.

5. Industry Application Examples

Industry	typical gas consuming equipment	pressure demand	suggestions on Selection of Air Compressor
automobile Manufacturing	spraying line, pneumatic tools	7-10bar	frequency conversion screw machine (10%-20% margin)
food Processing	packaging machine, conveyor belt	5-7bar	oil-free air compressor (equipped with high-efficiency filter)
laser cutting	cutting head	16bar	high pressure piston machine (pressure staged air supply)

summary: According to the air consumption to choose the air compressor to consider the air volume, pressure, energy efficiency, control mode and future expansion. It is recommended to determine the best selection scheme through professional evaluation tools or consulting manufacturers, combined with measured data.