The main function of the fermentor is to make the gas disperse well in the liquid phase; to make the material mix more evenly, so that the other liquid which is not uniform can be suspended or fully emulsified; to make the solid particles suspend evenly in the liquid phase; in addition, to strengthen the heat transfer and mass transfer between phases.

　　1. How many systems does fermentation equipment usually consist of?

　　Fermentation equipment usually consists of sterilization system, temperature control system, fermentation system and aerodynamic system.

　　2. What are the dangerous stages in the operation of fermentor and how to deal with them?

　　Fermentor, steam generator and air compressor are all pressure vessels, so we should be careful in operation. Sterilization (air sterilization and solid sterilization) is dangerous, so the whole process of sterilization must be watched, and no one is allowed to leave.

　　Before fermentation, air digestion and solid digestion, all cover screws, probe and feeding port screws of fermentation tank must be tightened. Open the water inlet taps of fermentation tank and steam generator.

　　Before fermentation, turn on the air compressor. When the pressure of the air compressor reaches 0.6MPa, turn on the power supply of the fermentation tank. In case of sterilization, turn on the steam generator and air compressor, and then turn on the power supply of fermentation tank. During the fermentation process, when the fermentation tank is overpressured (≥ 0.15Mpa): set the intake flow to 0, if it still can't be controlled, turn off the air compressor; when no one is on duty at night, cancel the do speed correlation control. During fermentation, the tank pressure must be positive, usually 0.02-0.05mpa.

　　3. Why is positive pressure required for tank pressure in fermentation process?

　　During the fermentation process, the positive pressure of the fermentation tank is required to prevent the air carrying bacteria from entering the tank and causing pollution, and to prevent the pollution caused by small particles falling from the shaft seal. And a certain pressure will be conducive to oxygen dissolution, increase dissolved oxygen. Another function of fermentation tank pressure is to buffer and prevent air backflow caused by sudden power failure. Keeping tank pressure can prevent air backflow at the moment of power failure.

　　4. The function of air compressor in fermentation process and the opening and closing time?

　　The air compressor must be opened in the process of air digestion, actual digestion, fermentation and sampling. 

　　The main functions are as follows:

　　① Keep tank pressure.

　　② Provide oxygen.

　　③ Provide power for pneumatic valve. 

　　④ Blow dry the air filter.

　　The working pressure at the outlet of the air compressor must reach 0.6MPa to maintain the normal operation of the fermentation tank. It can be opened before fermentation and sterilization, and can only be closed after the end of the tank. During the fermentation process, when the fermentation tank is overpressured (≥ 0.15Mpa), if the air flow is set to 0, the tank pressure can not be controlled, the air compressor must be shut down.

　　5. What should be paid attention to when using the steam generator?

　　In the use of steam generator, attention should be paid to:

　　① The steam generator is used in air, real and sampling. The steam generator is a pressure vessel and should be operated carefully. During sterilization (air sterilization, real sterilization) and sampling, the whole process must be guarded, and no one is allowed to leave.

　　② When the fermentor is in use, open the water inlet tap of the steam generator, close the blowdown valve, open the steam discharge valve, and open the main steam inlet valve of the fermentor.

　　③ Turn on the steam generator power, there will be a water shortage alarm sound, water pump operation make-up, when it reaches the predetermined water level, stop the alarm, water pump stop make-up.

　　④ Pay close attention to the water level change of steam generator. If there is no water inflow in case of fault and the water level drops below the scale line, shut down and turn off the power supply immediately.

　　⑤ When heating the steam generator, temporarily close the steam valve. When the pressure reaches the working pressure, slowly open the steam valve and use the steam normally.

　　⑥ After use, turn off the power. If it is not used for a long time, the water inlet tap shall be closed and the water in the water tank shall be drained after the steam generator is cooled.

　　⑦ The steam generator usually starts to work 20-30min before sterilization or sampling, and the working pressure of the steam generator is 0.4-0.7mpa.

　　6. How to proceed with the sterilization of empty can?

　　① The air digestion is usually carried out before the actual digestion (sterilization by actual loading) or after cleaning the fermentation tank at the end of fermentation. It refers to the sterilization of tanks, pipes, valves, filters, etc.

　　② Open the steam generator and air compressor, pull out the pH and do electrodes, plug them with cap screws and tighten them. Other cover screws and feeding port screws must be tightened, and the mirror window of fermentation tank shall be equipped with protective plate.

　　③ The water in the jacket must be emptied before the air elimination, and the fermentor must be filled with about 5L water (just submerge the temperature electrode probe).

　　④ Turn on the power of fermentation tank, log in the system, click "start" to enter sterilization control → sterilization parameter setting. Sterilization speed of empty can is set to 0RPM, stirring stop temperature is set to 0 ℃, sterilization stable temperature is set to 121 ℃, sterilization time is set to 10 ~ 30min, generally 20min, sterilization is completed, tank pressure is set to 0.05Mpa, temperature is set to 37 ℃, flow is set to 30.0l/min after sterilization, click "start", sterilization can be automatically carried out according to sterilization parameters.

　　⑤ When the temperature of the tank reaches 70 ℃, open the bottom valve and the discharge valve to pass steam to sterilize the bottom valve and the discharge valve.

　　⑥ The whole process of sterilization of empty cans must be supervised by someone. If there is an alarm, it should be handled and reported immediately. Sterilization tank pressure ≤ 0.15Mpa.

　　⑦ The steam generator, fermentor and air compressor shall be shut down in sequence after the air disinfection.