Fermentation Tank Sterilization Procedures
Proper sterilization is essential to ensure safe, contamination-free fermentation. Below is a complete step-by-step guide for sterilizing a stainless steel fermentation tank.
Pre-Sterilization Checklist
Before starting the sterilization process, carefully inspect the system:
- Ensure all piping connections are properly installed and secure
- Check all interfaces, plugs, threaded ports, and bolts are tightly fixed
- Confirm availability of air, steam, and cooling water supply
- Turn off all equipment operations
- Decide whether to enable mixing or automatic sterilization mode
- Monitor the pressure gauge continuously
- Tank pressure and jacket pressure must not exceed 0.3 MPa
Initial Valve Settings and Heating
Follow these steps to begin the sterilization process:
- Turn off all steam valves (LS1, LS2, LS3, LS4)
- Close valve PA3, keep the flowmeter open, and close SD2
- Open exhaust valve VT1, then jacket drain valve BD1, and finally steam valve LS2
- Allow steam to heat the jacket
- Keep pressure below 0.3 MPa
- Close air inlet valve PA4, open BD3 and BD4, then open steam valve LS1
- When temperature exceeds 100°C, adjust VT1 to maintain pressure
- Open steam valves for sterilization:
- LS3 & F1 → Sampling valve
- LS4 & F3 → Bottom valve
- At 115°C–121°C, open S1 & F2 if required
Sterilization Phase and Fermentation Preparation
- At 115°C–121°C, open PA4 to allow steam into the tank
- Steam pressure must be above 0.11 MPa
- Maintain 121°C for 30 minutes (adjust time if necessary)
- Keep pressure between 0.11 MPa – 0.3 MPa
- After sterilization:
- Close valves S1, F1, F2, F3
- Shut all steam valves and BD1
- Open PA3, adjust VT1, and open PA4
- At 115°C, open SD2 and start intermittent cooling
- At 95°C, close BD3 and BD4, switch to temperature control mode
- When the tank reaches the desired temperature, activate fermentation mode
