How much pressure is the air compressor used in the biological fermentation industry?

Official explanation on the pressure parameters of air compressors in the biological fermentation industry

In the biological fermentation process, the pressure setting of the air compressor needs to comprehensively consider microbial metabolic characteristics, fermentation equipment operating conditions and energy efficiency management requirements. After industry research and technical analysis, the specifications for the selection of pressure parameters are as follows:

1. Core pressure interval specifications
According to the characteristics of the fermentation process, the exhaust pressure of the air compressor is recommended to be set within the range of 0.3- 3.5 bar (g), of which:

1. Normal operating conditions: The pressure range of 1.8- 2.5 bar (g) can cover more than 80% of fermentation scenarios, and is suitable for mainstream processes such as aerobic bacterial cultivation and enzyme preparation production.
2. special applications：
   • Laboratory scale fermentation system: 0.8- 2.5 bar (g) can meet the oxygen supply needs of small fermentation tanks
   • Large-scale industrial fermentation device: 3.0-3.5bar(g) pressure setting is suitable for high-density cultivation and high-viscosity material fermentation scenarios

2. Key elements of pressure setting

1. Fermentation tank operating parameters：
   • Tank height: For every 1 meter increase in liquid column height, approximately 0.1 bar compensation pressure needs to be increased
   • Material characteristics: High viscosity medium needs to be increased by 0.2- 0.5 bar to overcome fluid resistance
   • Back pressure control: The vertical height from the fermentation liquid level to the exhaust port produces about 0.1 bar static pressure per meter
2. Pressure drop in piping system：
   • Precision filter: HEPA filter produces a pressure drop of 0.1- 0.15 bar
   • Steam sterilization device: Tubular heat exchanger increases resistance by 0.05- 0.1 bar
   • Pipe elbows: Each 90° elbow causes approximately 0.02 bar equivalent length loss
3. Process fluctuation compensation：
   • A pressure margin of 10-15% needs to be reserved to deal with differences in raw materials between batches
   • When multiple fermentation tanks are used in parallel, set according to the maximum required tank pressure

3. Technical Guidelines for Equipment Selection

1. Model adaptation principles：
   • Main air supply system: Oil-free screw or centrifugal air compressors are preferred to ensure that the oil content of the compressed air is ≤0.01mg/m³
   • Standby system: Piston air compressor can be configured, but three-level filtration device needs to be installed
2. Frequency conversion control strategy：
   • Adopt pressure closed-loop control system and achieve ±0.1bar accuracy control through PID algorithm
   • Equipped with permanent magnet variable frequency motor, maintaining ≥92% energy efficiency in the 50-100% load range
3. Energy saving optimization plan：
   • Pressure-flow linkage control is implemented, and compressor speed is adjusted according to real-time gas demand of fermentation tank.
   • Multi-unit staged air supply is adopted to avoid energy waste caused by frequent loading and unloading of single unit.

4. Operation and maintenance specifications

1. Pressure verification cycle：
   • Quarterly use of digital pressure gauge for full-scale verification
   • Pressure sensors at key process points need to be zero-point calibrated monthly
2. Handling of abnormal operating conditions：
   • When the pressure drops suddenly exceed 0.3 bar, immediately check the filter for clogging
   • If the pressure continues to be high, check the setting value of the air tank safety valve

When setting air compressor pressure parameters, enterprises should establish a three-dimensional model including fermentation tank parameters, pipeline characteristics, and process requirements, and optimize the pressure distribution through CFD fluid simulation. It is recommended to configure an intelligent pressure management system to collect 12 key parameters in real time to form a dynamic optimization plan for pressure-flow-energy efficiency. On the premise of ensuring the stability of the fermentation process, the comprehensive energy efficiency of the system can be improved by 15-20%.