Choosing the right air compressor volume requires comprehensive consideration gas demand, equipment characteristics and environmental factors and other factors. The following is a detailed selection guide:
1. Key Considerations
- gas Demand Analysis
- statistics of total gas consumption: List the rated gas consumption of all gas-consuming equipment (e. g., pneumatic tools, production line equipment) and consider peak gas consumption (e. g., during peak production hours).
- Reserved allowance: It is recommended that the gas balance should be at least 10%-20%. If the gas end is far away from the air compressor or there is a production expansion plan, the balance can be increased to 20%-30%.
- Formula Reference:
required gas volume = total gas volume × 1.1~1.2 (coefficient)
(For example, if the total gas consumption is 20m & sup3;/min, the recommended gas selection is 22-24m & sup3;/min)
- device characteristic matching
- pressure demand: Select the pressure level according to the equipment requirements (such as 7bar, 8bar), and consider the pipeline pressure loss (recommended pressure margin 1-2bar).
- Air compressor type:
- piston type: Suitable for small displacement and low pressure scenarios (such as maintenance workshops).
- screw type: Cost-effective, suitable for most industrial scenarios (such as manufacturing).
- Centrifugal: Suitable for continuous operation with large displacement (such as chemical plants).
- Energy efficiency grade first-class energy efficiency (specific power ≤ 7.2kW/(m & sup3;/min)) is preferred, and the energy saving effect is remarkable.
- Environmental Impact Assessment
- temperature: High temperature resistant models shall be selected or cooling measures shall be added in high temperature environment.
- Humidity: High humidity areas need to strengthen the drying of air compressor.
- Elevation: The air in high altitude areas is thin, and the air volume parameters need to be corrected.
2. selection steps
- calculate total gas consumption
- instrumental statistical method: Summarize the air consumption of all gas-consuming equipment (refer to equipment nameplate or supplier data).
- measurement method: When the production line is running, use a flowmeter to measure the actual gas consumption of key nodes.
- Select air compressor type and specification
- small displacement (<10m & sup3;/min): Piston or small screw machines are preferred.
- Medium displacement (10-50m & sup3;/min): Select screw type air compressor, and select frequency conversion or power frequency according to the fluctuation of gas consumption.
- Large displacement (>50m & sup3;/min): Select centrifugal or multiple screw machines in parallel.
- Determine pressure and power
- pressure: Terminal pressure + pipeline loss (usually plus 1-2bar margin).
- Power: Choose the matching motor power according to the air volume and pressure, and avoid "big horse-drawn cart" or "small horse-drawn cart".
3. selection recommendations
- avoid Common Mistakes
- blind selection of large models: Excessive air compressor will frequently load and unload, resulting in increased energy consumption and oil emulsification.
- Neglect the alternative: It is recommended to configure spare air compressors for key production lines to prevent shutdown due to single failure.
- Optimize gas allocation
- multiple joint control: For scenes with large air consumption fluctuations, power frequency + frequency conversion air compressor can be combined to give consideration to efficiency and adjustment flexibility.
- intelligent control: Adjust the gas volume in real time through the Internet of Things monitoring system to avoid energy waste.
- Consulting Professionals
- provide detailed gas consumption data (such as equipment list and gas consumption curve) to air compressor manufacturers to obtain customized solutions.
- Consider full life cycle costs (including energy consumption, maintenance, accessories, etc.).
4. example calculations
scene: The filling line of a food factory needs to drive 10 pneumatic filling machines, each with a rated gas consumption of 2m & sup3;/min, the peak gas consumption is 1.5 times of the total gas consumption, and the pressure requirement is 7bar.
Calculation:
- total gas consumption= 10 units × 2m & sup3;/min = 20m & sup3;/min
- peak gas consumption= 20m³/min × 1.5 = 30m³/min
- type selection gas volume= 30m & sup3;/min × 1.2 (margin) = 36m & sup3;/min
- pressure selection= 7bar + 1bar (margin) = 8bar
recommended Scheme: Select 2 sets of 20m & sup3;/min screw air compressor (one for use and one for standby), or one 37m & sup3;/min frequency conversion screw machine.
Summary: Air compressor capacity selection needs to be "tailored" to balance current needs and future expansion, combined with professional advice to ensure the accuracy and economy of selection.
