Fermentation tanks eliminate hidden dangers of equipment contamination

### Ensuring Fermentation Tank Integrity and Preventing Contamination

#### **1. Ensuring Fermentation Tank Sealing**

- **Importance**: Proper sealing of fermentation tanks is critical to prevent contamination.

- **Inspection**: Before use, check for:

- Agitation system issues.

- Mechanical seal tightness.

- Loose screws, blockages, or leaks in tank piping and interlayers.

- **Mechanical Seals**:

- Replace traditional packing seals with mechanical seals for better performance.

- Ensure precise installation and alignment of the agitator shaft to prevent leakage.

- Use multi-spring balanced mechanical seals to offset shaft deflection.

#### **2. Removing the Sight Glass Flushing Pipe**

- **Problem**: Steam pipes for sight glass flushing can introduce contamination due to unsterile condensate.

- **Solution**:

- Remove steam pipes to reduce contamination risk.

- Use high-brightness sight glass lights for visibility in foggy conditions.

#### **3. Using PVDF Membranes for Air Purification**

- **Advantages**:

- PVDF membranes offer high filtration accuracy and flow rates.

- They are moisture-insensitive and hydrophobic, overcoming issues with traditional filters like cotton.

- **Validation**:

- Monitor filter performance by passing filtered air through sterilized medium and checking for sterility over time.

#### **4. Regular Monitoring and Control Systems**

- **Sterilization Requirements**:

- Use high-temperature, supersaturated steam for sterilization.

- Maintain accurate sterilization temperature (around 110°C) and pressure (above 0.5 MPa).

- **Monitoring**:

- Regularly test temperature probes and pressure sensors.

- Use temperature as the primary reference for larger tanks.

#### **5. Valve Selection and Maintenance**

- **Sealing Requirements**:

- Use steam-grade seals for fermentation equipment.

- Prefer soft-seal valves with replaceable PTFE gaskets for better sealing and wear resistance.

- **Inspection**:

- Check upper seals to prevent media leakage through the valve stem.

- Replace packing materials with expanded PTFE for improved sealing.

#### **6. Addressing Dead Corners and Air System Monitoring**

- **Dead Corners**:

- Monitor sterility testing to identify contamination sources, especially in dead corners.

- **Air System**:

- Ensure sterility in the air purification system to prevent large-scale contamination.

By addressing these aspects, fermentation processes can minimize contamination risks and ensure consistent production quality.