Dairy Fermentation Tank Working Principle and Operation
Working Principle
Sterile Environment Maintenance
The fermentation process has extremely high sterility requirements to prevent contamination by unwanted microorganisms. Fermentation tanks use sealed design and steam sterilization to thoroughly sterilize the tank body, pipelines, and internal accessories before fermentation, ensuring a pure fermentation environment.
Temperature Control
Microbial growth and metabolism are highly sensitive to temperature. Different microorganisms have optimal growth temperature ranges. For example, the optimal temperature for yeast fermentation producing alcohol is typically 25-30 deg C. Fermentation tanks are equipped with temperature control systems using jackets or coil structures, utilizing circulating heating media such as hot water or cooling media such as cold water to regulate tank temperature, maintaining it within the optimal range.
Aeration and Stirring
For aerobic fermentation, adequate oxygen supply is critical. By introducing sterile air into the tank and using stirring devices to disperse air into micro-bubbles, the gas-liquid contact area increases, meeting microbial oxygen demands. Stirring also uniformly distributes nutrients in the fermentation liquid, promoting full contact between microorganisms and nutrients while aiding heat dissipation to prevent local overheating.
pH Regulation
Microbial metabolic activity causes changes in fermentation liquid pH. An appropriate pH is necessary for normal microbial growth and metabolism. Fermentation tanks typically include pH detection and control systems. When pH deviates from the set range, acid or alkali solutions can be automatically added for adjustment.
Standard Operation Process
Step 1: Equipment Preparation
- Comprehensively inspect all components to ensure they are intact and undamaged
- Check that pipe connections are tight with no leakage
- Verify temperature, pH, and dissolved oxygen sensors are working properly and calibrate them
- Perform thorough cleaning and sterilization of the tank and related pipelines. High-temperature steam sterilization or chemical sterilization methods may be used
Step 2: Culture Medium Preparation and Inoculation
- Accurately prepare culture medium according to fermentation process requirements
- Ensure nutritional content meets microbial growth and metabolism needs
- Transfer prepared medium to tank using aseptic techniques
- Under sterile conditions, inoculate appropriate amount of microbial seed liquid based on specific fermentation process and microbial characteristics
Step 3: Fermentation Process Control
- After fermentation starts, closely monitor all parameters
- Adjust temperature, aeration rate, and stirring speed based on microbial growth and fermentation progress
- In early fermentation, microbial growth is vigorous and oxygen demand increases. Appropriately increase aeration and stirring speed
- As fermentation proceeds and metabolites accumulate, pH may change. Adjust pH promptly
- Regularly sample fermentation liquid for testing: analyze microbial concentration, substrate consumption, and product generation indicators
Step 4: Fermentation Completion and Post-Processing
- When fermentation reaches target or endpoint, stop the process
- Transfer fermentation liquid through sterile pipelines to subsequent processing equipment
- Clean and disinfect the fermentation tank to prepare for next fermentation session
- Properly treat waste gas and wastewater to meet environmental requirements
Conclusion
Correctly mastering fermentation tank principles and usage methods is key to achieving efficient, stable fermentation production. From design principles to strict process control at every step, ensuring optimal microbial growth environments delivers high-quality fermentation products for various industries.
