How to maintain the fermenter and common problems

In order to ensure the normal operation of the fermenter, in addition to being familiar with the working principle of the equipment and the structure, performance of each component and the role of pipelines and valves, users should also pay attention to and strengthen the maintenance and maintenance of the equipment, only to achieve careful maintenance of the equipment can ensure that the equipment is in the best state and extend the working life of
the equipment.
Daily inspection maintenance and regular inspection and maintenance of the fermentation tank system can be divided into daily and regular two ways, both of which are indispensable
.
Daily inspection and maintenance (the monitoring content in the operation of the equipment should be recorded accordingly) whether the system pressure and tank pressure are stable within the specified range
.
Whether the stirring system, temperature control system, and solenoid valve sound are normal
.
Whether the culture medium color is normal
.
Whether the temperature and dissolved oxygen PH display parameters are consistent
with the settings.
Whether the liquid level in the tank is normal
.
Whether the valve pipe joints and each interface are normal, and whether there is leakage
.
Regular inspection and maintenance every three months, the equipment needs to be fully inspected and corrected
.
Turn off all power sources, water sources, and gas (steam) sources
.
Carefully check whether all seals and sealing ends of the system are normal
.
If there is deformation, aging, scratching, damage, it must be replaced
.
Check the integrity of the sterilization filter, and replace
it if it is damaged or blocked.
Motor carbon brush wear and commutator, bearing, connector, mixing system
.
Check whether all switches, buttons, electrical appliances, electronic components, fixing screws, and nuts of the electrical controller are loose or
heated.
Cleaning maintenance and maintenance of the fermenter tank body Cleaning the fermentation tank is a place
that is in direct contact with the material.
The degree of surface finish and the cleanliness of internal components are factors
that directly affect the infection.
Therefore, after each fermentation and before reuse, the tank and related equipment must be cleaned in time, and attention should be paid to electrical components and electrode interfaces when cleaning, so that water can not enter and be damp
.
Before cleaning, the PH and DO electrodes should be taken out for maintenance according to their requirements (see electrode maintenance).

The cleaning tank can be carried out with water intake, motor stirring, and heating, if the water can not be cleaned after multiple water changes, the top cover should be opened and the parts
in the tank should be brushed with a soft brush.
Here's how: control the switch and power switch, remove the top cover electrode, the motor and its wiring plug
.
Unplug the intake hose condenser quick coupling Remove the hose and connector on the intake filter; Remove the top cover and stirring vertically upwards, and place it horizontally on a flat tabletop, pad it, do not collide with the shaft and impeller, and brush the can and internal parts
with neutral detergent.
Note: When the tank lid is moved and cleaned, only the shaft sleeve or top cover can be grasped, and the mixing shaft, impeller and other deformable parts
can not be grasped.
At the same time of cleaning, some O-rings such as tanks and outlet valves should be inspected, such as deformation, aging, scratches and other phenomena need to be replaced
in time.
After cleaning and reinstalling, dry its appearance and tank rack with a rag
.
Tighten the six fastening screws of the tank lid, balance the force and pay attention to the balance of the gap between the
can and the tank seat.
Special care should be taken for the cleaning of glass fermenters, and do not collide when disassembling; When tightening the lid fastening screws, the force must be balanced, and pay attention to the balance of the gap, so as to avoid damage to the glass jar.

The tightness test installs the electrode, motor, cable, inlet and outlet hose, condenser inlet and outlet joints in place; After installation, the ventilation (0.
2MPa) in the tank should be tested for tightness
.
Here's how: close the 401, 304, 106 valves; Tighten each interface, plug, electrode fastening cap on the tank; Open the 207, 208, 209 valve and air compressor, adjust the 206 valve to keep the tank pressure at about 0.
2MPa; unplug the quick coupling on the DX, the tank pressure drop speed should be less than 0.
02Mpa/h
.
Carry out 2-3 hours trial operation of the system, and if there is a problem, it can be officially used
.
If the fermenter needs to be cultivated again in the short term, it should be sterilized
.
Sterile air is then introduced and retained under pressure
.
If it is ready to be stopped for a long time, it should be sterilized, and then the water in the tank and tank should be put away, the tightening screw of the tank lid should be relaxed, the electrode should be taken out for maintenance and storage, the remaining water of the tank and each pipeline should be cleaned, all valves and power supplies should be closed, and the dust cover
should be covered.
After the second culture, use a clean rag to remove the electrical box, cables and other joints and other tank parts.
Precautions Before sterilization, check and adjust the output pressure of the steam generator to ensure that the pressure ≤ 0.
35Mpa (steam generator pressure gauge display value).

During the sterilization process, the air pressure in the tank should be checked to ensure that the pressure < 0.
15Mpa
.
Before fermentation, the output pressure of the air compressor should be checked and adjusted to ensure that the pressure ≤ 0.
4Mpa (air compressor pressure gauge display value), and the output pressure of the pressure reducing valve should be adjusted ≤ 0.
25Mpa
.
During fermentation, the air pressure in the tank should be checked to ensure that the pressure ≤ 0.
10Mpa
.
The use and maintenance of DO and pH electrodes must be carried out according to the requirements, otherwise it is easily damaged
.
All electrical devices are strictly prohibited from water ingress, moisture and pollution
.
If you have any questions, please contact
us as follows.
Maintenance of the mixing system The mixing system includes the mixing shaft, stirring slurry, and mechanical seal.

Bearings, couplings and motors, etc
.
Daily maintenance: frequently check the operation of the mixing shaft, the heating of the motor and the emission of abnormal noise, and often check whether the bolts are loose
.
Check the wear of the mechanical seal every year to ensure the normal operation of the mechanical seal and avoid unnecessary sterilization
.
If a double-acting mechanical seal is used, it is necessary to always pay attention to the change of the sterile water level, and if the liquid level drops, it indicates that the seal gap leaks and should be dealt with
immediately after the end of fermentation.
Check the wear of the oil seal and the carbon brush of the motor every year, as well as the wear of the oil seal and bearing.
Maintenance and maintenance of sterilization air system 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, and the air tank drain valve should be drained twice
a day during the fermentation process.
Filter maintenance and maintenance sterilization temperature should be controlled below 125 °C During the sterilization process, it should be noted that the sterilization temperature of the filter should be controlled below
125 °C.
Because the filter material is too high a temperature, the binder will fall off and cause the filter to fail
.
The replacement of the filter element Because the air contains a lot of dust, after the filter is used for a period of time, the micropores of the filter element will gradually be blocked, which on the one hand leads to increased resistance, causing a serious lack of air flow and an increase in air pressure drop, thereby affecting the ventilation volume, and may cause infection
.
This is where it needs to be replaced
.
Due to the large differences in air quality in different places, there is no accurate service life, generally up to more than
6 months.
The replacement standard is that the minimum air flow is not less than 1.
5 times
the volume of the tank.
(The pressure difference between the outlet of the pressure reducer and the tank pressure is not less than 1kg/cm2) At the end of 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 cleaned
with compressed air.
If the fermentation broth is viscous or contains fine particles, it is best to remove the air distributor, then unscrew the plug and rinse with
water.
At the same time
, ensure the smooth ventilation of the small hole.
Maintenance and maintenance of steam systems Steam systems include steam filters, steam line valves, etc
.
During use, we should always pay attention to ensure that the steam pressure is constant
.
The filter element of the steam filter will also clog after a period of use and the filter element
needs to be replaced.
During operation, attention should be paid to opening the steam valve, do not immediately open it fully, which will impact the steam filter element, and in severe cases, the filter element will be broken or leaked and make it invalid
.
Maintenance of dissolved oxygen electrode Maintenance of dissolved oxygen electrode If it is not used for a long time, please remove the electrode from the tank and put it in the electrode box
.
If the sensitive film is dirty, please rinse it with clean water, and if it cannot be rinsed, do not scratch it with any hard object to avoid hanging the sensitive film
.
Do not soak in liquids such as water or moist air such as vapor to erode cable connectors and electrode connectors
.
Do not scratch the sensitive film with sharp objects to avoid damage
.
HOW TO CHANGE THE MEMBRANE AND ELECTROLYTE METTLER TOLEDO OXYGEN ELECTRODE AFTER A SERIES OF INSPECTIONS BEFORE LEAVING THE FACTORY, THE ELECTRODE ITSELF HAS AN ELECTRODE MEMBRANE, BUT BECAUSE IT TAKES A CERTAIN CYCLE DURING PURCHASE AND TRANSPORTATION, IT IS BEST TO REPLACE THE ELECTROLYTE BEFORE USE
.
If the electrode signal generates errors (long response time, mechanical damage, increased current in oxygen-free medium, etc.
), it is necessary to replace the membrane, replace the electrolyte maintenance work, which is carried out every three months: place the electrode in a vertical position, unscrew the old electrode membrane
.
Rinse the internal electricity with waterCarefully dry the polar body with cotton paper, check whether there is electrolyte between the inner electrode body and the stainless steel housing, and gently shake it off
if there is any residual electrolyte.
After using for a period of time, if you find that the silver ring of the electrode body is black, you can
use more than 1000 mesh fine sandpaper to polish it.
Inspect the o-rings and springs for mechanical damage and replace
them if needed.
Pour the electrolyte into the membrane to be replaced, the liquid level is controlled below the thread, add more electrolyte appropriately, can avoid affecting the polarization of the electrode due to less electrolyte, put the electrode in a vertical position and gently screw the membrane on the electrode body, pay attention to the principle of "two in and out of one" when screwing the electrode membrane, to avoid breaking the membrane due to the excess liquid in the membrane can not be discharged in time, and finally the electrode film should be tightened, no O-ring color (black) is exposed, and the exuding electrolyte is dried
with cotton paper.
Due to the sealing effect of the O-ring, the membrane will be easily tightened, and if it needs to be tightened hard or the process cannot be easily completed, it may not be in the correct position
.
After each film change or electrolyte change, the electrode must be repolarized and calibrated (see operating instructions for details) polarization: after replacing the new electrolyte or replacing the new membrane, it must be continuously energized for more than 7 hours, that is, polarization, and accurate calibration
can be carried out after polarization.
Polarization first, calibration later
.
Calibration: For specific operation steps, please refer to the oxygen transmitter operation manual
.
Maintenance of solenoid valve solenoid valve is used for the cooling of fermentation tank, solenoid valve core stuck, valve core seal ring failure and solenoid coil damage can cause solenoid valve failure
.
Fault judgment: cooling valve failure: open the solenoid valve, the upper end face of the solenoid valve is non-magnetic, no cooling water discharge, and the coil is broken; Close the solenoid valve, cooling water leaks out of the drain, and the valve core seal fails; Open and close the solenoid valve, the drainage situation remains unchanged, and the valve core is stuck
.
In the case of ensuring the operation of the circulating pump and the smooth circulating pipeline, the biggest reason for the temperature to drop but not rise is the leakage of the solenoid valve or the valve core is stuck, and the other reason may be that the electric heater is burned out
.
Other maintenance of ferrule ball valve maintenance: Because the seals in the ball valve are made of two more hemispherical tetrafluoroethylene, after long-term use, there may be leakage
between the seal and the valve core.
Maintenance method: loosen the tube 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 to rotating the valve stem) Leakage of the compression joint: tighten the pressure cap on the joint
.
Maintenance of discharge valve: unscrew the bonnet, extract the spool, check whether the sealing ring is intact, otherwise replace the sealing ring
.
Note 1.
During the fermentation process, it is strictly forbidden to open the drain valve of the filter suddenly and cause the fermentation broth to flow back, and do not let the pressure in the tank be greater than the pressure
of the pipeline.
2.
When the power is suddenly out, the air system of the fermenter should be quickly turned off to ensure that the tank pressure and air system do not cause negative pressure, and the pressure gauge on the filter and the pressure gauge of the fermentation tank cannot be zero
.
3.
The pressure of steam sterilization filter shall not exceed 0.
15Mpa
.
4.
When the air is dissipated, the sewage valve in the jacket should be opened, and the tank pressure cannot be reduced to zero
when the real consumption is cooled.
5
.
After the end of actual consumption, the jacket should first open the drain valve, and then open the inlet valve to prevent high water pressure in some areas, causing equipment damage or pressure gauge failure.
6.
When opening steam, the intake valve should be opened first and then the valve should be opened (look at the pressure gauge reading above the sub-cylinder).

7
.
When transporting hot water, the valve above the hot water pump should be set ajar.
8
.
The Y-shaped filter should be checked regularly, and the flow meter should be repaired in time when the aeration volume is reduced or the flow meter does not go up during fermentation.
9.
As soon as the motor of the seed tank is turned on, the cooling water must be turned on in advance; All motors cannot be idle.

10.
The leakage of the diaphragm valve should be disassembled and cleaned and then installed (do not use excessive force when closing to avoid damaging the diaphragm!).
)
。 11.
The ball valve and diaphragm valve are closed clockwise and opened counterclockwise; The two-way valve ("one" valve) is closed horizontally and opened
along the pipeline.
12.
When feeding materials, attention should be paid to whether the connection between the silicone tube of each feeding bottle and the corresponding peristaltic pump is correct and stable
.
Common faults and troubleshooting methods Fault cause analysis Troubleshooting method Close the valve, the tank pressure can not be maintained 1.
The fastening screws of the can lid flange are not tightened or the tightness of the screws is not the same
.
2.
The seal is damaged or there is a gap
at the interface.
3.
Air
leakage in pipe fittings or valves.
4.
Mechanical seal wear.

1.
Tighten the screws to maintain consistent
tightness.
2.
Check the seal or replace
it.
3.
Tighten the nut or replace
.
4.
Replace the sealing device
.
When steam sterilizing, the temperature rises too slowly 1.
The steam pressure is low and the air supply is insufficient
.
1.
Check whether the electric heating tube is burned out
.
2.
Whether the pressure gauge value of the upper room of the sub-cylinder is normal
.
Fermentation broth backflows from the air line 1.
Caused by
misoperation.
Pay attention to the operation
.
Temperature control failure 1.
The sensor or lead is damaged
.
2.
The meter is damaged
.
1.
Check the sensor
.
2.
Check the meter or replace
it.
Dissolved oxygen is too low 1.
Insufficient
air supply.
2.
The filter is clogged
.
3.
Pipeline
valve leakage.
1.
Open the valve or increase the supply pressure
.
2.
Check the filter and replace the filter element
.
3.
Check the pipeline valve
.
PH display failure 1.
The pH electrode is damaged
.
2.
PH electrode is clogged
.
1.
Check or replace
the PH electrode.
2.
Clean the electrode
.
Dissolved oxygen shows malfunction Dissolved oxygen electrode membrane damage Replace the membrane