design and working of an industrial fermenter

An industrial fermenter, also known as a bioreactor, is a vessel used to carry out fermentation processes for large-scale production of biochemicals, pharmaceuticals, and other products through the cultivation of microorganisms or cells. Here is a detailed description of its design and working:

 

Design of an Industrial Fermenter

1. Vessel Body:

   • Material: Typically made from stainless steel to ensure durability, ease of cleaning, and resistance to corrosion and microbial contamination.
   • Shape: Usually cylindrical with a rounded top and bottom to facilitate mixing and cleaning.

2. Capacity:

   • Fermenters vary in size from small laboratory-scale (1-10 liters) to large industrial-scale (up to several thousand liters).

3. Agitation System:

   • Impellers: Mechanical devices like Rushton turbines or marine impellers are used to mix the contents of the fermenter.
   • Baffles: Vertical strips attached to the inner walls of the vessel to prevent vortex formation and improve mixing efficiency.

4. Aeration System:

   • Sparger: A device at the bottom of the fermenter that introduces air or oxygen to the culture medium.
   • Air Filters: Ensure sterile air is supplied to prevent contamination.

5. Temperature Control:

   • Heating/Cooling Jackets: Surround the fermenter to control the temperature of the culture medium.
   • Sensors: Temperature sensors monitor the temperature inside the vessel.

6. pH Control:

   • Probes: pH sensors measure the acidity or alkalinity of the medium.
   • Addition of Acid/Base: Automated systems add acid or base to maintain the desired pH level.

7. Foam Control:

   • Antifoam Agents: Chemicals added to reduce foam formation.
   • Foam Sensors: Detect foam levels and trigger the addition of antifoam agents.

8. Sterilization:

   • The fermenter and its accessories are sterilized using steam or chemical methods to prevent contamination.

9. Sampling and Harvesting Ports:

   • Sampling Ports: Allow for periodic sampling of the culture for analysis.
   • Harvest Ports: Used to remove the final product.

10. Control System:

    • PLC (Programmable Logic Controller): Automates and monitors the fermentation process.
    • SCADA (Supervisory Control and Data Acquisition): Provides a graphical interface for operators to control and monitor the process.

Working of an Industrial Fermenter

1. Preparation:

   • The fermenter is cleaned and sterilized before use.
   • The culture medium is prepared and added to the vessel.

2. Inoculation:

   • Microorganisms or cells are introduced into the culture medium.

3. Fermentation:

   • The fermenter is sealed, and the process is started.
   • The agitation system ensures thorough mixing of the culture medium, maintaining even distribution of nutrients, temperature, and oxygen.
   • The aeration system provides the necessary oxygen for aerobic fermentation or maintains an anaerobic environment if required.
   • Temperature and pH are continuously monitored and adjusted to optimal levels for the growth of the microorganisms or cells.

4. Monitoring:

   • Throughout the fermentation process, various parameters such as pH, temperature, dissolved oxygen, and biomass concentration are monitored and controlled.
   • Samples are taken periodically to check the progress of the fermentation and to ensure product quality.

5. Harvesting:

   • Once the fermentation is complete, the culture broth is removed from the fermenter.
   • The product is separated from the biomass and other impurities through filtration, centrifugation, or other downstream processing methods.

6. Cleaning and Sterilization:

   • After harvesting, the fermenter is cleaned and sterilized, making it ready for the next batch.

Key Considerations

• Sterility: Ensuring the fermenter and all inputs (air, nutrients, etc.) are sterile is crucial to prevent contamination.
• Scalability: The design should allow for easy scaling up or down depending on production needs.
• Process Control: Advanced control systems are essential for maintaining optimal conditions and maximizing yield.

By understanding and optimizing these aspects, industrial fermenters can efficiently produce a wide range of bioproducts on a large scale.