Maintenance, cleaning, and upkeep of the fermentation tank system

In order to ensure the normal operation of the fermentation tank, users must not only be familiar with the working principle of the equipment, the structure and performance of each component, as well as the role of pipelines and valves, but also pay attention to and strengthen the maintenance and upkeep of the equipment. Only by carefully maintaining the equipment can it be guaranteed to be in the best condition and extend its service life.

The fermentation tank systemDaily inspection and maintenance, as well as regular inspection and maintenance

The maintenance and upkeep of the fermentation tank system can be divided into two ways: daily and regular, both of which are indispensable.

Daily inspection and maintenance(The monitoring content during equipment operation should be recorded accordingly)

Is the system pressure and tank pressure stable within the specified range. Is the sound of the mixing system, temperature control system, and solenoid valve normal. Is the color of the culture medium normal. Temperature and dissolved oxygenPHDisplay whether the parameters match the settings. Is the liquid level in the tank normal. Check if the valve pipe joints and interfaces are normal and if there are any leaks.

Regular inspection and maintenance

Every three months, a comprehensive inspection and correction of the equipment is required. Cut off all power, water, and gas sources.

Carefully check whether all sealing rings and sealing ends of the system are normal. if anyDeformation, aging, scratches, and damage must be replaced. Check the integrity of the sterilization filter, and replace it if there is any damage or blockage.

The wear of motor carbon brushes and the condition of rectifiers, bearings, couplings, and mixing systems.

Check all switches, buttons, electrical and electronic components, fixing screws, and nuts of the electrical controller for looseness and overheating.

Cleaning, maintenance and upkeep of fermentation tank body

wash

The fermentation tank body is the place that comes into direct contact with the material. The degree of surface smoothness and cleanliness of internal components are factors that directly affect bacterial contamination. Therefore, it is necessary to clean the tank and related equipment in a timely manner after each fermentation and before reuse. When cleaning, attention should be paid to electrical components and electrode interfaces to prevent water and moisture from entering.

Before cleaning, it should be removedPHTheDOThe electrode should be maintained according to its requirements (see electrode maintenance).

The cleaning of the tank can be carried out in conjunction with water intake, motor stirring, and heating. If the tank cannot be cleaned after multiple water changes, the top cover should be opened and the components inside the tank should be brushed with a soft bristled brush. The method is as follows: control the switch and power switch, remove the top cover electrode, motor and its connecting plug. Remove the quick connector of the condenser from the intake hose and detach the hose and connector on the intake filter; Remove the top cover together with the mixer vertically upwards and place it horizontally on a flat table. Place it on a cushion without colliding with the shaft and impeller, and use neutral detergent to scrub the tank body and internal components.

Note:When moving and cleaning the tank cover, only the shaft sleeve or top cover should be grasped, and the mixing shaft, impeller, and other easily deformed parts should not be grasped. During cleaning, it is necessary to address issues such as the tank and outlet valveOCheck the sealing ring, if foundDeformation, aging, scratches and other phenomena need to be replaced in a timely manner. After cleaning and reinstalling, the surface and tank rack should be wiped dry with a cloth. Tighten the six fastening screws on the can cover with balanced force and pay attention to the even gap between the can and the can seat. Special care should be taken when cleaning glass fermentation tanks, and do not collide during disassembly and assembly; When tightening the screws of the can cover, be sure to apply balanced force and pay attention to the even gap to avoid damaging the glass can body.

Sealing test

Install the electrodes, motors, cables, inlet and outlet hoses, and condenser inlet and outlet water joints in place; After installation, the tank body should be ventilated（0.2MPa）Conduct a sealing test. The method is as follows: Close 401、304、106 Valve;

Tighten every interface, plug, and electrode fastening cap on the tank body; open207、208、209Valves and air compressors, regulating206Valve maintains tank pressure0.2MPaabout; unplugDXThe quick connector on the tank should have a pressure drop rate of less than0.02Mpa/h. Conduct a system review2--3Test run for hours, and only after addressing any issues can it be officially put into use.

Fermentation tank ready for use

If it is necessary to cultivate fermentation again in the short term, it should be sterilized. Then introduce sterile air and maintain pressure for later use.

If it is intended to be used for a long time, it should be sterilized, then the water tank and tank should be drained, the fastening screws of the tank cover should be loosened, the electrode should be taken out for maintenance and storage, the remaining water in the tank and various pipelines should be drained, all valves and power should be closed, and a dust cover should be covered. After secondary cultivation, use a clean cloth to remove any debris from electrical boxes, cable joints, and other tank components.

Precautions　

Before sterilization, the output pressure of the steam generator should be checked and adjusted,Ensure this pressure≤0.35Mpa(Steam generator pressure gauge display value). During the sterilization process, the air pressure inside the tank should be checked,Ensure this pressure<0.15Mpa.

Before fermentation, the output pressure of the air compressor should be checked and adjusted,Ensure this pressure≤0.4Mpa(Air compressor pressure gauge display value),Adjust the output pressure of the pressure reducing valve≤0.25MpaDuring the fermentation process, the pressure inside the tank should be checked,Ensure this pressure≤0.10Mpa.DOThepHThe use and maintenance of electrodes must be carried out according to requirements, otherwise they are easily damaged. All electrical devices are strictly prohibited from being exposed to water, moisture, or pollution. For any questions, please contact us using the following methods.

Maintenance of mixing system

The mixing system includes a mixing shaft, a mixing slurry, and a mechanical seal. Bearings, couplings, motors, etc.

Daily maintenance: Regularly check the operation of the mixing shaft, the heating condition of the motor, and the emission of abnormal noise. Regularly check whether the relevant bolts are loose.

Check the wear of mechanical seals annually to ensure their normal operation and avoid unnecessary bacterial contamination.

If a double end mechanical seal is used, it is important to pay close attention to changes in the sterile water level. If the liquid level drops, it indicates a leak in the sealing gap and should be dealt with immediately after fermentation is complete.

Check the wear of oil seals and carbon brushes of motors every year, as well as the wear of oil seals and bearings.

Maintenance and upkeep of sterilization air system

The sterilization air system includes air compressors, coarse filters, fine filters, diaphragm valves, and air distributors.

In daily maintenance, attention should be paid to the operation of the air compressor. During the fermentation process, the drain valve of the gas storage tank should be drained twice a day. The sterilization temperature for filter maintenance and upkeep should be controlled at125Below ℃

During the sterilization process, it is important to control the sterilization temperature of the filter within a certain range125Below ℃. Because the material of the filter will peel off its adhesive at too high a temperature, causing the filter to fail.

Replacement of filter cartridge

Due to the presence of a large amount of dust in the air, the micropores of the filter element will gradually become clogged after a period of use. This leads to an increase in resistance, causing severe air flow and pressure drop, thereby affecting ventilation and potentially causing bacterial contamination. At this point, it needs to be replaced.

Due to significant differences in air quality across different regions, there is no exact lifespan, and it is generally achievable6More than a month. The replacement standard is that the minimum air flow rate should not be less than the tank volume1.5Twice. The pressure difference between the outlet of the pressure reducer and the tank pressure shall not be less than1kg/cm²）

After each fermentation, the air distributor needs to be cleaned. If the properties of the fermentation broth are similar to water, water can be added to the tank and then compressed air can be used for cleaning. If the fermentation broth is viscous or contains small particles, it is best to remove the air distributor, unscrew the plug, and rinse with water. At the same time, ensure smooth ventilation through the small hole.

Maintenance and upkeep of steam system

The steam system includes steam filters, steam pipeline valves, etc. During use, it is important to regularly ensure a constant steam pressure.

The filter element of the steam filter will also clog after a period of use and needs to be replaced. During the operation, it is important to note that when opening the steam valve, do not immediately fully open it, as this can impact the steam filter element and, in severe cases, break or leak the element, causing it to fail.

Maintenance of dissolved oxygen electrode

Maintenance of dissolved oxygen electrode

If not used for a long time, please remove the electrode from the can and place it in the electrode box. If the sensitive film is dirty, please rinse it with clean water. If it cannot be washed off, do not scratch it with any hard object to avoid damaging the sensitive film. Do not soak the cable joints and electrode joints in liquid or humid air such as water or steam.

Do not use sharp objects to scratch sensitive film to avoid damage.

How to change the membrane and electrolyte

METTLER TOLEDOThe oxygen electrode undergoes a series of inspections before leaving the factory. The electrode itself has an electrode film, but due to the need for a certain period of time during purchase and transportation, it is best to replace the electrolyte before use.

If there is an error in the electrode signal (such as long response time, mechanical damage, increased current in anaerobic medium, etc.), it is necessary to replace the membrane and electrolyte for maintenance work, which should be carried out every three months:

Place the electrode in a vertical position and unscrew the old electrode film. Rinse the inner electrode body with water and carefully dry it with cotton paper to check for electrolyte between the inner electrode body and the stainless steel casing,

If there is any residual electrolyte, gently shake it clean. After using for a period of time, if the silver ring of the electrode body turns black, it can be used1000Polish with fine sandpaper above the eye level. Check itOIs there any mechanical damage to the ring and spring? If necessary, they can be replaced. Pour the electrolyte into the membrane to be replaced, keeping the liquid level below the thread. Add more electrolyte appropriately to avoid affecting electrode polarization due to insufficient electrolyte. Place the electrode in a vertical position and gently screw the membrane onto the electrode body. When twisting the electrode membrane, be careful“Two in, one out”The principle is to avoid bursting the membrane due to the inability to discharge excess liquid in a timely manner. Finally, the electrode membrane should be tightenedOUntil the color of the sealing ring (black) is exposed, wipe off the leaked electrolyte with cotton paper. due toOThe sealing effect of the O-ring makes it easy for the membrane to be tightened. If it needs to be tightened forcefully or this process cannot be easily completed, it may not be tightened in the correct position.

After each membrane or electrolyte change, the electrode must be repolarized and calibrated (see operating instructions for details)

Polarization: After replacing the electrolyte or membrane with a new one, continuous power must be applied7An hour or more is polarization, and accurate calibration can only be performed after polarization. Polarization first, calibration later.

Calibration: For specific operating steps, please refer to the oxygen transmitter operation manual.

Maintenance of solenoid valve

Electromagnetic valves are used for cooling fermentation tanks. The valve core of the electromagnetic valve is stuck, the sealing ring of the valve core fails, and the electromagnetic coil is damaged, all of which can cause the failure of the electromagnetic valve.

Fault diagnosis: Cooling valve failure: Open the solenoid valve, the upper end face of the solenoid valve is non-magnetic, no cooling water is discharged, and the coil is damaged; Turn off the solenoid valve, there is cooling water leakage from the drain outlet, and the valve core seal has failed;

Open and close the solenoid valve, the drainage situation remains unchanged, but the valve core is stuck. The main reason why the temperature only drops without increasing while ensuring the operation of the circulation pump and the smoothness of the circulation pipeline is that the solenoid valve leaks or the valve core is stuck, and the other reason may be that the electric heater is burnt out.

Other maintenance

Maintenance of sleeve ball valve: Due to the fact that the sealing components inside the ball valve are made of two hemispherical tetrafluoroethylene, there may be leakage between the sealing components and the valve core after prolonged use. Repair method: Loosen the sleeve joint nuts at both ends of the valve, and then tighten the cylindrical joints at both ends of the valve. (Under normal circumstances: there should be a certain resistance when rotating the valve handle)

Leakage of the card sleeve connector: simply rotate the pressure cap on the connector. Maintenance of discharge valve: Unscrew the valve cover, extract the valve core, check if the sealing ring is intact, otherwise replace the sealing ring.

Precautions

1.During the fermentation process, it is strictly prohibited to suddenly open the drain valve of the filter to cause the fermentation liquid to flow back, and do not let the pressure inside the tank exceed the pipeline pressure.

2.When there is a sudden power outage, the air system of the fermentation tank should be quickly shut down to ensure that the tank pressure and air system do not create negative pressure. The pressure gauge on the filter and the pressure gauge of the fermentation tank should not drop to zero.

3.The pressure during steam sterilization of sterilization filters shall not exceed0.15Mpa.

4.During the process of air disinfection and actual disinfection, the drain valve inside the jacket should be opened. During actual disinfection and cooling, the tank pressure should not drop to zero.

5.After the actual consumption is completed, the jacket should first open the drainage valve, and then open the inlet valve to prevent equipment damage or pressure gauge failure caused by high water pressure in some areas.

6.When opening steam, the intake valve should be opened first and then the air valve should be opened (pay attention to the pressure gauge reading above the cylinder).

7.When delivering hot water, the valve above the hot water pump should be in a semi open position.

8.YThe shape filter should be checked regularly, and if the ventilation rate decreases or the flow meter cannot be connected during fermentation, it should be repaired in a timely manner.

9.Once the motor of the seed tank is turned on, the cooling water must be turned on in advance; All motors cannot run idle.

10.If the diaphragm valve leaks, it should be disassembled, cleaned, and reinstalled (do not apply excessive force when closing to avoid damaging the diaphragm!).

11.The ball valve and diaphragm valve close clockwise and open counterclockwise; The two-way valve ("one" valve) is closed horizontally along the pipeline and opened along the pipeline.

12.When replenishing materials, attention should be paid to whether the connection between the silicone tube of each replenishment bottle and the corresponding peristaltic pump is correct and stable.

Common faults and troubleshooting methods