The core of temperature control technology in fermentation tanks is to maintain the temperature stability of the fermentation system to adapt to the metabolic needs of microorganisms/cells. The overall process can be divided into two parts: temperature control system composition and process execution logic, as follows:

1. Core components of temperature control system
① Jacket/coil: It is the main heat exchange structure of the fermentation tank. The jacket wraps around the outer wall of the tank, while the coil is built into the tank. Both achieve temperature regulation through the circulation of heat exchange medium.
② Temperature control unit: equipped with multiple high and low temperature integrated units or chillers (including heating modules), responsible for providing constant temperature medium for the jacket/coil, and integrating temperature sensors, temperature control valves, circulation pumps and other components.

③ Monitoring and control system: Platinum resistance and other temperature sensors are installed inside the tank to collect real-time temperature data of the fermentation broth. Through PLC or industrial control system linkage with the temperature control unit, closed-loop regulation is achieved.
2. Specific temperature control process logic
① Preheating stage: Before fermentation, the temperature control unit outputs the heated medium (such as thermal oil, pure water), which is circulated through a jacket/coil to raise the temperature of the culture medium or empty tank to the preset fermentation starting temperature (such as 28-37 ℃, depending on the strain), ensuring that microorganisms can quickly start metabolism after inoculation.
② Fermentation stage
Cooling is the main focus: The microbial fermentation process releases a large amount of metabolic heat. At this time, the temperature control unit switches to cooling mode, delivering low-temperature medium to take away excess heat and accurately maintaining the set temperature; If there is a temperature fluctuation, the system will automatically adjust the medium flow rate or the opening of the temperature control valve to avoid local supercooling/overheating.
Special scenario heating: For low-temperature fermentation strains (such as certain lactic acid bacteria), or when the ambient temperature is too low and the tank temperature drops, the temperature control unit starts the heating module to supplement heat to stabilize the temperature.
③ Post fermentation stage: After fermentation is completed, the temperature can be adjusted through a temperature control system as needed (such as increasing the temperature to inactivate the bacterial strain, or decreasing the temperature to preserve the fermentation broth) to prepare for subsequent extraction processes.
3. Key process requirements
① Uniformity: By optimizing the jacket structure and adding a stirring device (with temperature control), the temperature deviation in different areas of the tank is ensured to be ≤ ± 1 ℃, avoiding local temperature differences that affect the activity of the bacterial strains.
② Timeliness of response: The temperature control system needs to have rapid heat exchange capability to cope with sudden increases in metabolic heat during the fermentation process and prevent fermentation failure caused by temperature exceeding the threshold.
③ Medium compatibility: The heat exchange medium needs to be compatible with the fermentation system (such as purified water and food grade thermal oil required in the pharmaceutical industry), and insulation and anti-corrosion treatment of the medium circulation loop should be done well.