Fermentation is a reaction process in which specialized metabolites are produced and accumulated in large quantities through the growth, cultivation, and chemical changes of microorganisms (or animal and plant cells). Therefore, a fermentation tank is a tank that provides the environment and conditions for the completion of microbial fermentation processes. Fermentation tanks commonly include mechanical ventilation fermentation tanks, anaerobic fermentation tanks, solid fermentation tanks, liquid fermentation tanks, fully automatic fermentation tanks, stainless steel fermentation tanks, strain fermentation tanks, small fermentation tanks, beer fermentation tanks, wine fermentation tanks, edible mushroom fermentation tanks, double fermentation tanks, triple fermentation tanks, etc.

Fermentation tanks have functions such as heating, cooling, sterilization, and constant temperature, which can provide a suitable fermentation environment for microbial growth, namely suitable temperature and pressure, and nutrition.Fermentation tank_Fully automatic fermentation tank_

Biological fermentation tank manufacturer

The culture medium inside the fermentation tank provides the necessary carbon, nitrogen, oxygen, growth factors, water, etc. for microbial growth. Fermentation tanks are mainly used to cultivate and ferment various bacterial cells and fermented products. The fermentation tank has functions such as automatic temperature control, automatic pH adjustment, automatic data recording, and automatic feeding, greatly simplifying operation and reducing the chance of bacterial contamination. It is the main bioreactor of modern fermentation equipment.

Fermentation tank finished product image

2、 Purpose of fermentation tank

The structure of a fully automatic fermentation tank used for anaerobic fermentation (such as producing alcohol and solvents) can be relatively simple. Fermentation tanks used for aerobic fermentation (such as the production of antibiotics, amino acids, organic acids, vitamins, etc.) require continuous introduction of a large amount of sterile air into the tank, and to consider the utilization rate of the introduced air, the structure of the fermentation tank is relatively complex. Commonly used fermentation tanks include mechanical stirring fermentation tanks, bubble fermentation tanks, and gas lift fermentation tanks. The fermentation process of dairy products and alcoholic beverages is a sterile and pollution-free process. The fermentation tank adopts a sterile system to avoid and prevent microbial contamination in the air, greatly extending the shelf life and purity of the product. The tank is specially designed and installed with sterile breathing holes or sterile positive pressure fermentation system. The tank is equipped with a Milo plate or a labyrinth jacket, which can be heated or cooled by circulating a heating or cooling medium. The capacity of fermentation tanks varies from 300-15000L in different specifications. Fermentation tanks can be divided into laboratory small fermentation tanks, pilot production fermentation tanks, large fermentation tanks, etc. according to their usage scope. Fermentation tanks are widely used in industries such as dairy products, beverages, biotechnology, pharmaceuticals, and fine chemicals. The tank body is equipped with a sandwich layer, insulation layer, and can be heated, cooled, and insulated. The tank body and upper and lower filling heads (or conical shapes) are both processed by spinning R angles, and the inner wall of the tank is polished with a mirror finish to ensure no hygiene dead corners. The fully enclosed design ensures that the materials are always mixed and fermented in a pollution-free state. The equipment is equipped with air breathing holes, CIP cleaning nozzles, manholes, and other devices. Classification of fermentation tanks: According to the equipment of the fermentation tank, it is divided into mechanical stirring and ventilation fermentation tanks and non mechanical stirring and ventilation fermentation tanks; According to the growth and metabolic needs of microorganisms, they are divided into aerobic fermentation tanks and anaerobic fermentation tanks. A fermentation tank is a device that mechanically stirs and ferments materials. This device adopts an internal circulation method, using a stirring blade to disperse and crush bubbles. It has a high dissolved oxygen rate and good mixing effect. The tank body is made of imported stainless steel SUS304 or 316L, and is equipped with an automatic spray cleaning machine head to ensure that the production process meets GMP requirements.

Fermentation tank, seed tank

3、 Composition and structure of fermentation tank

(1) Tank body

The tank body of a fermentation tank is welded from a cylinder and an elliptical or disc-shaped head, and the head and cylinder of a small fermentation tank are connected by flanges. The top of the tank is equipped with a sight glass and a light mirror for easy observation of the fermentation status inside the tank. The connections on the top of the fermentation tank include: feed pipe, feed pipe, exhaust pipe, inoculation pipe, and pressure gauge connection. The connections on the tank body include cooling water inlet and outlet pipes, air inlet pipes, sampling pipes, thermometer pipes, and measurement and control instrument interfaces.

(2) Size ratio of tank body

The dimensions of each part of the tank have a certain proportion, and fermentation tanks are generally slender due to the special needs of fermentation, with a height to diameter ratio of about 1.7-2.5.

(3) Blender

Fermentation tanks are usually equipped with two sets of agitators, with a spacing S of approximately three times the diameter of the agitators. For large fermentation tanks and those with high liquid depth HL, three or more sets of agitators can be installed. The bottom set of agitators is usually closer to the outlet of the air duct, and the distance C from the bottom of the tank is generally equal to the diameter Di of the agitator, but it should not be less than 0.8Di, otherwise it will affect the circulation of the liquid.

Axial agitator: blade type, propeller type

Radial (turbine) agitator (Disc turbine): straight blades, curved blades, arrow blades

(4) Barrier board

The function of the baffle is to change the direction of the liquid flow from radial flow to axial flow, causing the liquid to vigorously flip and increasing dissolved oxygen.

Full baffle condition: it refers to adding accessories in the tank at a certain number of revolutions while the shaft power remains unchanged. To reach the full baffle condition, the following requirements must be met:

(5) Defoamer

The defoamer is used to break foam. The commonly used forms of defoamers include serrated, comb shaped, and orifice plate. The aperture of the orifice plate is about 10-20 millimeters. The length of the defoamer is approximately 0.65 times the diameter of the tank.

(6) Coupling

The mixing shaft of a large fermentation tank is relatively long and often divided into two to three sections. A coupling is used to firmly and rigidly connect the upper and lower mixing shafts. There are two commonly used types of couplings: drum shaped and clamp shell shaped. Small fermentation tanks can use flanges to connect the stirring shaft, and the shaft connection should be vertical with the centerline aligned.

(7) Bearing

In order to reduce vibration, medium-sized fermentation tanks usually have bottom bearings inside the tank, while large fermentation tanks have middle bearings. The horizontal position of the bottom and middle bearings should be adjusted appropriately. Lubricating oil cannot be added to the bearings inside the tank, and liquid lubricated plastic bearings (such as polytetrafluoroethylene, etc.) should be used. The gap between the bearings and the shaft is often taken as 0.4-0.7% of the shaft diameter. To prevent journal wear, a shaft sleeve can be added to the shaft in contact with the bearing.

(8) Variable speed device

The test tank adopts a continuously variable transmission device. The commonly used variable speed devices for fermentation tanks include V-belt transmission, cylindrical or spiral bevel gear reduction devices, among which V-belt variable speed transmission is more convenient.

(9) Shaft seal

The function of the shaft seal is to seal the gap between the top or bottom of the tank and the shaft, preventing leakage and contamination of bacteria. There are two commonly used types of shaft seals: stuffing box and end face shaft seal.

① A stuffing box type shaft seal is composed of a stuffing box body, a stuffing bottom liner, a stuffing cover, and clamping bolts, etc., to achieve a sealing effect on the rotating shaft.

The advantage of a stuffing box shaft seal is its simple structure. The main disadvantages are: there are many blind spots, it is difficult to completely sterilize, and it is prone to leakage and bacterial contamination; The wear of the shaft is severe; The friction power consumption is high after the packing is compressed; Short lifespan, frequent maintenance, and high labor consumption.

② End face type shaft seal, also known as mechanical shaft seal. The sealing effect is achieved by the pressure of elastic elements (springs, bellows, etc.) to tightly adhere the smooth surfaces of the moving and stationary rings perpendicular to the axis, and to rotate relative to each other to achieve sealing.

(10) Heat exchange device for fermentation tank

① Jacketed heat exchange device

This device is commonly used in fermentation tanks with smaller volumes; The height of the jacket should be slightly higher than the height of the stationary liquid level. The advantages of this device are: simple structure; Easy to process, no cooling equipment inside the tank, few dead corners, easy to clean and sterilize, beneficial for fermentation. Its disadvantages

Yes: The heat transfer wall is thick, the cooling water flow rate is low, and the cooling effect during fermentation is poor.

② Vertical snake tube heat exchange device

This device is a vertical snake tube grouping installation inside the fermentation tank, with four, six, or eight groups depending on the diameter of the tubes, with a volume of 5 cubic meters

The above fermentation tanks often use this type of heat exchange device. The advantage of this device is that the flow rate of cooling water inside the pipe is high; High heat transfer coefficient. This cooling device is suitable for areas where the cooling water temperature is low and the amount of water used is relatively small. However, in areas with high temperatures, the cooling water temperature is relatively high, making it difficult to cool down during fermentation. The fermentation temperature often exceeds 40 ℃,

Due to the impact on fermentation yield, frozen salt water or chilled water cooling should be used, which increases equipment investment and production costs. In addition, curved positions are more prone to erosion.

③ Vertical tube heat exchange device

This device is symmetrically grouped and installed in a fermentation tank in the form of tubes. Its advantages are: easy processing, suitable for areas with high temperatures and abundant water sources. The disadvantage of this device is that its heat transfer coefficient is lower than that of a serpentine tube, and it requires a larger amount of water.

Fermentation tank equipment diagram

4、 Anhui Xiangpai Machinery is a manufacturer of biological fermentation tanks. Below are the characteristics of fermentation tanks

1. It can be cleaned online with CIP and sterilized with SIP (121 ° C/0.1MPa).