Key Components of Fermenter Design
Fermenter Vessel
Made of stainless steel (SS 316) to withstand pressure and corrosion.
Equipped with a cooling jacket or coils for temperature regulation.
Agitation System
Uses impellers (e.g., Rushton turbine, marine propellers) for proper mixing.
Baffles prevent vortex formation and improve aeration.
Aeration System
Spargers (porous rings or pipes) introduce sterile air for oxygen supply.
Airflow rate is controlled to optimize oxygen transfer.
Temperature Control
Thermocouples and heat exchangers maintain the optimal temperature.
Cooling coils prevent overheating from microbial metabolism.
pH Control
Sensors monitor pH, and acids or alkalis are automatically added to maintain stability.
Foam Control
Foam sensors detect foam formation.
Antifoam agents (silicone-based) are added to prevent overflow.
Nutrient Feeding System
Used in fed-batch fermentation to supply fresh nutrients gradually.
Prevents substrate inhibition and enhances yield.
Sterilization System
Steam-in-Place (SIP) for vessel sterilization.
Clean-in-Place (CIP) for cleaning pipelines and sensors.
Pressure & Exhaust Control
Pressure sensors maintain vessel integrity.
Exhaust gas system removes CO₂ and other gases.
Sampling & Harvesting System
Sterile sampling ports allow periodic culture analysis.
Harvesting ports collect the final product for downstream processing.
Controls in Large-Scale Fermenters
Effective controls ensure consistency, efficiency, and safety in fermentation processes.
These include:
Temperature Control: Automatic regulation via cooling/heating jackets.
pH Control: Automated addition of acids/bases.
Dissolved Oxygen (DO) Control: Adjust aeration/agitation rates.
Pressure Control: Maintain optimal pressure conditions to avoid contamination.
Foam Control: Addition of antifoaming agents to prevent foam formation.
Feeding Control: Automatic nutrient addition (fed-batch fermentation).
Sterility Control: Automated sterilization cycles and aseptic sampling.
