CN118638603A - A self-turning microbial agent fermentation tank - Google Patents

Abstract

The present invention relates to the technical field of microbial fermentation equipment, and specifically discloses a self-turning microbial inoculant fermentation tank, which includes a tank body and a tank cover. A mixing device is arranged inside the tank body, and the mixing device includes a cylinder, an upper shaft and a lower shaft. The cylinder is vertically suspended inside the tank body under the support of the upper shaft and the lower shaft. The upper shaft is connected to a power device. An inner spiral wing and an outer spiral wing are respectively fixed to the inner and outer sides of the cylinder, and the inner spiral wing and the outer spiral wing drive the fermentation liquid to flow in opposite directions. When the self-turning microbial inoculant fermentation tank is working, during the rotation of the mixing device, the inner spiral wing and the outer spiral wing jointly drive the fermentation liquid to reciprocate and turn up and down to achieve a good mixing effect; the fermentation tank has high mixing efficiency and good mixing effect, the rotation speed of the mixing device is low, the rotation resistance is small, the energy consumption in the mixing process is reduced, foam is not easily generated during the mixing process, and the physical damage to the microorganisms can be significantly reduced.

Description

A self-turning microbial agent fermentation tank

Technical Field

The invention relates to the technical field of microbial fermentation equipment, in particular to a self-turning microbial inoculant fermentation tank.

Background Art

Microbial inoculant fermentation tank is a kind of equipment used for microbial inoculant fermentation production. Its main function is to provide a suitable growth environment for microorganisms so that they can grow and reproduce quickly and efficiently. When fermenting microorganisms, it is necessary to stir the fermentation liquid to mix the components in the fermentation liquid evenly, make the temperature at each position consistent, and promote gas exchange to improve the efficiency and quality of microbial fermentation. Therefore, the stirring device is a necessary component of the microbial inoculant fermentation tank.

At present, most microbial fermentation tanks use mechanical stirring devices to mix the fermentation liquid. The stirring device is generally composed of a main shaft and multiple groups of stirring paddles. The stirring paddles are used to stir the fermentation liquid, and the baffles set on the side wall of the tank body are used to make the fermentation liquid produce violent convection, thereby achieving the purpose of uniform mixing. During the rotation of the stirring paddle, the fermentation liquid at different positions is subjected to obvious differences in stirring force. The corners of the tank body are farthest from the stirring paddles and are subjected to the least stirring force. In order to avoid the formation of a mixing dead angle and affect the mixing effect, the stirring paddle must be rotated at a higher speed. On the one hand, the high-speed rotation of the stirring paddle consumes more energy, which increases the operating cost of the microbial fermentation tank. On the other hand, the fermentation liquid close to the stirring paddle will be excessively stirred and easily produce a large amount of foam, which needs to be defoamed, increasing the workload and energy consumption of the microbial fermentation tank. In addition, the high-speed rotating stirring paddle will cause certain physical damage to the microorganisms in the fermentation liquid, and have a certain adverse effect on the fermentation yield and microbial activity.

Summary of the invention

In order to solve the technical problems existing in the prior art, the present invention provides a self-turning microbial inoculant fermentation tank, in which a mixing device is installed inside the tank body, and the mixing device is composed of a cylinder, an inner spiral wing and an outer spiral wing. During the rotation of the mixing device, the fermentation liquid can be driven to circulate back and forth fully and orderly, and turn up and down, so as to achieve a good mixing effect; based on the above-mentioned mixing mechanism, the rotation speed of the mixing device is low and the rotation resistance is small, which reduces the energy consumption in the mixing process, effectively reduces the generation of foam, and reduces the physical damage to the microorganisms in the fermentation liquid.

In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

A self-turning microbial inoculant fermentation tank comprises a tank body and a tank cover which are sealed and fixedly connected, a discharge port is fixed at the bottom of the tank body, a mixing device is arranged inside the tank body, and a feed port and a power device are fixed on the tank cover, wherein the mixing device comprises a vertical cylinder and an upper shaft and a lower shaft respectively fixed at the upper and lower ends of the cylinder; the upper shaft is rotationally sealed with an axial hole provided on the tank cover, the upper shaft is transmission-connected with the power device, and the lower shaft is rotationally matched with a supporting shaft sleeve fixed at the bottom of the tank body, so that the cylinder is suspended inside the tank body and can only perform rotational motion around the central axis; the upper and lower ends of the cylinder are both in an open state, and an inner spiral wing and an outer spiral wing for driving the fermentation liquid to flow are respectively fixed on the inner side and the outer side of the cylinder, and when the cylinder rotates, the inner spiral wing and the outer spiral wing drive the fermentation liquid to flow in opposite directions.

Compared with the prior art, the present invention has the following beneficial technical effects:

In the self-turning microbial inoculant fermentation tank, the cylinder divides the internal space of the tank body into intervals, and the inside of the cylinder is connected to the outside of the cylinder to form a closed circulation channel. During the rotation of the mixing device, under the joint drive of the inner spiral wing and the outer spiral wing, the fermentation liquid in the tank body circulates back and forth in the circulation channel and turns up and down, so that all the fermentation liquid fully and orderly participates in the mixing effect, and the fermentation liquid in the tank body is subjected to a balanced and consistent mixing force as a whole; during the reciprocating up and down turning process, the fermentation liquid converges from all sides and flows into the cylinder, and then flows out of the cylinder and disperses to all sides. After reciprocating convergence and dispersion, the fermentation liquid can achieve a good mixing effect. In the mixing mechanism adopted by the self-turning microbial inoculant fermentation tank, the role of the mixing device is not to directly stir and mix the fermentation liquid, but to drive the fermentation liquid to circulate back and forth so that the fermentation liquid is mixed evenly during the flow process. Therefore, the rotation speed of the mixing device is low and the rotation resistance is small, which reduces the energy consumption in the mixing process, is not easy to generate foam during the mixing process, and can also significantly reduce the physical damage to microorganisms.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the external structure of the self-turning microbial inoculant fermentation tank in Example 1.

FIG. 2 is a schematic diagram of the external structure of the self-turning microbial inoculant fermentation tank in Example 1 from another direction.

FIG3 is a schematic diagram of the structure of the self-turning microbial inoculant fermentation tank in Example 1 after partial cutaway.

FIG. 4 is a schematic diagram of the structure of the tank body in Example 1 after partial cutaway.

FIG. 5 is a schematic diagram of the structure of the tank cover and the mixing device in Example 1.

FIG. 6 is a schematic diagram of the structure of the mixing device in Example 1 after partial sectioning.

FIG. 7 is a schematic diagram of the flow of the fermentation liquid when the mixing device in Example 1 rotates in one direction.

FIG8 is a schematic diagram of the flow of the fermentation liquid when the mixing device in Example 1 rotates in another direction.

FIG. 9 is a schematic diagram of the internal structure of the self-turning microbial inoculant fermentation tank in Example 2.

FIG. 10 is a schematic diagram of the coordination state between the mixing device and the defoaming device in Example 2 when the mixing device rotates in the forward direction.

FIG. 11 is a schematic diagram showing the coordination state of the mixing device and the defoaming device in Example 2 when the mixing device rotates in the reverse direction.

In the figure:

1. Tank body, 101. circulating liquid outlet, 102. testing instrument access port, 103. sampling port, 104. circulating liquid inlet, 105. discharge port, 106. air inlet, 107. interlayer, 108. baffle, 109. supporting shaft sleeve;

2. Tank cover, 201, feed port, 202, exhaust port, 203, feed port;

3. Power plant;

4. mixing device, 401. cylinder, 402. upper shaft, 403. outer spiral wing, 404. spoke, 405. lower shaft, 406. air outlet blind pipe, 407. truncated cone, 408. air outlet hole, 409. inner spiral wing;

5. Defoaming device, 501. Rotating shaft sleeve, 502. Centrifugal turbine, 503. Driven wheel, 504. Driving wheel, 505. First transmission wheel, 506. Second transmission wheel, 507. Cover.

DETAILED DESCRIPTION

The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

Example 1

1 to 3 , the present embodiment discloses a specific structure of a self-flipping microbial inoculant fermentation tank, which includes a tank cover 2 and a tank body 1 distributed up and down, the tank cover 2 and the tank body 1 are sealed and fixedly connected, and according to the specifications and models of the fermentation tank, the fixed connection method can be selected from common methods such as fastening screws and locks; a discharge port 105 is fixed at the bottom of the tank body 1 for discharging the successfully fermented fermentation liquid, and a mixing device 4 is provided inside the tank body 1 to mix the fermentation liquid to ensure uniform distribution of substances in the fermentation liquid and promote gas exchange to improve the efficiency and quality of microbial fermentation; a feed port 201 is fixed on the tank cover 2 for feeding materials required for fermentation into the tank body 1, and a power device 3 is fixed on the tank cover 2, and the power device 3 is used to provide drive for the mixing device 4.

As shown in FIGS. 3 to 7 , the mixing device 4 comprises a cylinder 401, an upper shaft 402 and a lower shaft 405; the cylinder 401 is a cylindrical hollow cylinder in a vertical state, that is, the central axis of the cylinder 401 is in a vertical direction; the upper shaft 402 is fixed to the upper end of the cylinder 401 and extends upward, the upper shaft 402 is rotatably sealed with an axial hole opened on the tank cover 2, the upper end of the upper shaft 402 extends to the top of the tank cover 2 and is transmission-connected with the power device 3; the lower shaft 405 is fixed to the lower end of the cylinder 401 and extends downward, the lower shaft 405 is rotatably matched with a supporting sleeve 109 fixed to the bottom of the tank body 1; the central axes of the cylinder 401, the upper shaft 402 and the lower shaft 405 coincide with each other, and the cylinder 401, the upper shaft 402 and the lower shaft 405 are rotatably matched. The upper and lower ends of the cylinder 401 are supported by the upper shaft 402 and the lower shaft 405 respectively, so that the cylinder 401 is stably suspended inside the tank body 1 and can only rotate around its own central axis; the upper and lower ends of the cylinder 401 are both open, and the inner side of the cylinder 401 is fixed with an inner spiral wing 409 for driving the fermentation liquid inside the cylinder 401 to flow up and down, and the outer side of the cylinder 401 is fixed with an outer spiral wing 403 for driving the fermentation liquid outside the cylinder 401 to flow up and down; the spiral directions of the inner spiral wing 409 and the outer spiral wing 403 are opposite, that is, one is left-handed and the other is right-handed, so that when the cylinder 401 rotates, the inner spiral wing 409 and the outer spiral wing 403 drive the fermentation liquid to flow in opposite directions.

The mixing mechanism of this self-turning microbial agent fermentation tank is:

As shown in FIG. 7 , in the structure of the self-turning microbial inoculant fermentation tank, the cylinder 401 is suspended inside the tank body 1, and has the function of dividing the internal space of the tank body 1 into intervals. The inside of the cylinder 401 is connected with the outside of the cylinder 401 to form a closed circulation channel. When the microorganisms are fermented and cultured, it is ensured that the fermentation liquid level in the tank body 1 is higher than the cylinder 401, so that the cylinder 401 is completely immersed in the fermentation liquid. During the rotation of the mixing device 4, the fermentation liquid circulates back and forth in the circulation channel and turns up and down under the joint drive of the inner spiral wing 409 and the outer spiral wing 403, so that the tank body 1 All the fermentation liquids fully and orderly participate in the mixing action, and it is not easy to produce dead corners of mixing, so that the fermentation liquid in the tank body 1 is mixed evenly and uniformly as a whole, and there is no local excessive stirring; in the process of reciprocating up and down tumbling, the fermentation liquid converges from all sides and flows into the cylinder 401, and then flows out of the cylinder 401 and disperses to all sides. After the reciprocating convergence and dispersion, the fermentation liquid can achieve a good and efficient mixing effect; at the same time, in the process of circulating flow, the flow direction of the fermentation liquid will change, and the inner spiral wings 409 and the outer spiral wings 403 can also play a certain stirring role, which can further improve the mixing effect.

In the prior art in this technical field, the power device is usually composed of components such as a motor, a reduction mechanism and a coupling. Most motors have the functions of adjustable steering and speed. At the same time, the existing electromechanical control technology can easily realize the regulation of the motor steering and speed; therefore, a controller can be set in the self-turning microbial inoculant fermentation tank, and the power device can drive the mixing device to rotate in different directions under the control of the controller, and can adjust the rotation speed of the mixing device; thus, as shown in Figures 7 and 8, the speed, steering and other working states of the mixing device 4 are preset, so that the mixing device 4 rotates alternately in forward and reverse rotation, and the fermentation liquid can be driven to circulate alternately in different directions, so as to obtain better mixing effect and mixing efficiency; when switching the steering direction, the power device 3 enables the mixing device 4 to perform a buffer transition at a lower speed, which can reduce the workload of the mixing device 4 and improve the working stability and service life of the mixing device 4.

As is known to all, when fermenting and culturing microorganisms, the fermentation temperature needs to be regulated and controlled. Therefore, existing fermentation tanks are usually provided with heat exchange functions. It is common to install coils or tubes in the tank body and to adopt a jacketed structure for the tank body. In the present invention, the mixing mechanism adopted by the self-turning microbial inoculant fermentation tank is different from the past. During the operation of the mixing device, the fermentation liquid will flow back and forth in an orderly manner along the inner side of the tank body. Therefore, when the tank body adopts a jacketed structure, the self-turning microbial inoculant fermentation tank can achieve a very outstanding heat exchange effect; therefore, as shown in Figures 2 and 4, the tank body 1 is a jacketed structure. Specifically, the tank wall of the tank body 1 is a double-layer structure with an interlayer 107, and the tank body 1 is fixed with a circulating liquid inlet 104 and a circulating liquid outlet 101 that are connected to the interlayer 107.

As shown in Figures 7 and 8, in the above-mentioned mixing mechanism adopted by the self-turning microbial inoculant fermentation tank, the function of the mixing device 4 is not to directly stir and mix the fermentation liquid, but to drive the fermentation liquid to circulate and flow, so that the fermentation liquid is mixed during the flow. Based on this mixing mechanism, the rotation speed of the mixing device 4 is low and the rotation resistance is small, thereby reducing the energy consumption in the mixing process. There is no local excessive stirring in the mixing process, so it is not easy to generate foam. The mixing device 4 acts on the fermentation liquid in a relatively mild and balanced manner, which can significantly reduce the physical damage to the microorganisms and ensure the yield and activity of the microorganisms in the fermentation liquid.

Optionally, the self-turning microbial inoculant fermentation tank disclosed in this embodiment may also have one or more of the following technical features:

5 and 6 , a truncated cone portion 407 is fixed to the lower end of the upper shaft 402 and the upper end of the lower shaft 405, and the truncated cone portion 407 is fixedly connected to the cylinder 401 via a plurality of spokes 404 distributed at equal angles; thereby, it is possible to ensure that the upper shaft 402, the lower shaft 405 and the cylinder 401 have sufficient connection strength, while reducing the shielding of the two ports of the cylinder 401 by the connection structure, so as to reduce the obstruction to the flow of the fermentation liquid;

As shown in FIG1 , the tank body 1 is provided with a sampling port 103 for obtaining a fermentation liquid sample;

As shown in FIG1 , the tank body 1 is provided with a plurality of detection instrument access ports 102 for installing sensing probes of pressure, liquid level, pH, temperature, dissolved oxygen and other parameter measurement equipment;

As shown in FIG. 1 , the tank cover 2 is provided with a feeding port 203 to add materials such as agents, strains, pH regulators, etc. into the tank body 1 according to actual needs during the fermentation process;

As shown in FIG. 1 and FIG. 2 , the tank body 1 is provided with an air inlet 106 for inputting sterile air, and the tank cover 2 is provided with an exhaust port 202 for discharging waste gas; when it is necessary to set the air inlet 106 and the exhaust port 202 for the self-turning microbial inoculant fermentation tank, a more preferred method is:

3 to 7 , the air inlet 106 is located at the lower end of the tank body 1, an upwardly extending air outlet blind pipe 406 is fixed to the upper end of the lower shaft 405, and air outlet holes 408 are evenly distributed on the side wall of the air outlet blind pipe 406. The lower shaft 405 is sealed with the supporting shaft sleeve 109, and an air passage for connecting the air inlet 106 with the air outlet blind pipe 406 is provided in the lower shaft 405 and the supporting shaft sleeve 109; therefore, when sterile air is input through the air inlet 106, the air outlet blind pipe 406 rotates synchronously with the mixing device 4, and the sterile air can be released more dispersedly into the circulating fermentation liquid, which is more conducive to quickly and evenly mixing the sterile air and the fermentation liquid;

As shown in FIG. 3 and FIG. 4 , a plurality of baffles 108 extending up and down along the side wall are fixed in the tank body 1 . The baffles 108 can prevent the fermentation liquid from rotating horizontally in the tank body 1 , and circulate more efficiently.

Example 2

It is well known that when microorganisms are fermented and cultured, a certain amount of foam will be generated as the fermentation proceeds, especially during the mixing process, which will promote the generation of foam.

In the present invention, the self-turning microbial inoculant fermentation tank can effectively reduce the generation of foam based on the mixing mechanism it adopts. However, when the organic matter content in the fermentation liquid is high and continuous ventilation is required, a large amount of foam will inevitably be generated during the mixing process. In order to ensure the stable progress of fermentation, it is still necessary to provide a defoaming device.

At present, most microbial inoculant fermentation tanks use mechanical methods to achieve defoaming, that is, defoaming devices such as defoaming paddles, defoaming rakes or centrifugal turbines are installed on the main shaft to break the foam through physical action to achieve the purpose of defoaming. The shortcomings of the existing defoaming devices are: even if there is no foam above the liquid surface, the defoaming device is still driven by the main shaft to continue to operate, resulting in unnecessary energy consumption and increasing the operating energy consumption of the microbial inoculant fermentation tank. At the same time, the main function of the main shaft is to drive the mixing device or the stirring device to rotate, and the rotation speed of the main shaft is often difficult to make the defoaming device play an efficient defoaming effect.

In view of the above problems existing in the prior art, this embodiment discloses another implementation structure of a self-turning microbial inoculant fermentation tank, which is a further improvement made on the basis of the technical solution in Example 1.

As shown in FIG9 , the power device 3 can drive the mixing device 4 to rotate forward and reversely; a defoaming device 5 is installed at the lower side of the tank cover 2, and the defoaming device 5 includes a centrifugal turbine 502 and a cover 507; the centrifugal turbine 502 uses a rotating shaft sleeve 501 as a wheel axle, and the rotating shaft sleeve 501 is rotatably fixed on the upper shaft 402, and a driven wheel 503 is fixed on the upper end of the rotating shaft sleeve 501; a driving wheel 504 is rotatably fixed on the upper shaft 402, and the driving wheel 504 is connected to the upper shaft 402 through a ratchet mechanism. The one-way transmission feature of the mechanism is that when the mixing device 4 rotates forward, the upper shaft 402 cannot drive the driving wheel 504 to rotate. When the mixing device 4 rotates backward, the upper shaft 402 will drive the driving wheel 504 to rotate synchronously with it. The matching structure of the upper shaft 402 and the driving wheel 504 can be implemented with reference to the matching structure of the bicycle wheel axle and the flywheel in the prior art. The driving wheel 504 is connected to the driven wheel 503 in transmission. The lower end of the cover 507 is open, and the cover 507 is fixed to the lower side of the tank cover 2 and covers the outside of the centrifugal turbine 502.

Based on the above structure, the self-turning microbial inoculant fermentation tank can control the rotation direction of the mixing device 4 when it is working, so as to achieve the regulation of the operating state of the defoaming device 5; as shown in FIG10 , when the fermentation tank is operating normally, the mixing device 4 is rotated forward and the defoaming device 5 is in a stopped state, so as not to increase the operating energy consumption of the fermentation tank; as shown in FIG11 , when defoaming treatment is required, the mixing device 4 is rotated in the reverse direction, and the upper shaft 402 drives the centrifugal turbine 502 to rotate through the driving wheel and the driven wheel, and the centrifugal turbine 502 extracts the foam on its lower side, and the foam is thrown out at high speed by the centrifugal action and collides with the cover 507, thereby forcing the foam to burst, and achieving the purpose of defoaming; since the centrifugal turbine 502 is not directly fixedly connected to the upper shaft 402, there is a transmission component in the middle, and the speed ratio of the centrifugal turbine 502 to the upper shaft 402 can be adjusted by means of the transmission component, so that the centrifugal turbine 502 obtains a suitable speed, thereby achieving a better defoaming effect.

As for under what circumstances the mixing device needs to work in reverse rotation, reference can be made to common practices in the prior art; for example, a cycle can be set to make the mixing device work in reverse rotation periodically, that is, the defoaming device can be operated regularly to prevent excessive foam in the fermentation tank; for example, a monitoring element can be installed in the fermentation tank to monitor the amount of foam. When the amount of foam reaches a threshold, the mixing device will rotate in reverse to operate the defoaming device.

In this embodiment, as shown in Figure 9, the driving wheel 504 is transmission-connected with the driven wheel 503, and the transmission connection requirements of the driving wheel 504 and the driven wheel 503 can be met by adopting the common transmission method in the prior art. For example, a vertically extending transmission shaft is rotatably fixed on the lower side of the tank cover 2, and a first transmission wheel 505 and a second transmission wheel 506 are fixed on the transmission shaft. The first transmission wheel 505 is transmission-coordinated with the driving wheel 504, and the second transmission wheel 506 is transmission-coordinated with the driven wheel 503, thereby achieving the purpose that the driving wheel 504 can drive the driven wheel 503 to rotate; the first transmission wheel 505 and the driving wheel 504, as well as the second transmission wheel 506 and the driven wheel 503 can be transmission-coordinated with each other by common methods such as gears, belts, and chains.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

Claims (10)

1. The utility model provides an automatic-turning microbial agent fermentation cylinder, includes sealed fixed connection's jar body and cover, and jar body bottom is fixed with the bin outlet, and jar internal portion is equipped with mixing arrangement, is fixed with feed inlet and power device, characterized by on the cover: the mixing device comprises a vertically arranged cylinder, and an upper shaft and a lower shaft which are respectively fixed at the upper end and the lower end of the cylinder; the upper shaft is in rotary sealing fit with a shaft hole formed in the tank cover, the upper shaft is in transmission connection with the power device, and the lower shaft is in rotary fit with a bearing shaft sleeve fixed at the bottom of the tank body, so that the cylinder is suspended in the tank body and can only perform rotary motion around the central shaft; the upper end and the lower end of the cylinder are both in an open state, the inner side and the outer side of the cylinder are respectively fixed with an inner spiral fin and an outer spiral fin for driving the fermentation liquor to flow, and when the cylinder rotates, the inner spiral fin and the outer spiral fin drive the fermentation liquor to flow in opposite directions.

2. The automatic turning microbial inoculant fermenter of claim 1, wherein: the power device can drive the mixing device to rotate in different directions under the control of a controller, and can adjust the rotation speed of the mixing device.

3. The automatic turning microbial inoculant fermenter of claim 1, wherein: the lower end of the upper shaft and the upper end of the lower shaft are respectively fixed with a round platform part, and the round platform parts are fixedly connected with the cylinder through a plurality of spokes distributed at equal angles.

4. The automatic turning microbial inoculant fermenter of claim 1, wherein: the tank wall of the tank body is of a double-layer structure with an interlayer, and a circulating liquid inlet and a circulating liquid outlet which are communicated with the interlayer are fixed outside the tank body.

5. The automatic turning microbial inoculant fermenter of claim 1, wherein: the tank body is provided with a sampling port and a plurality of detecting instrument access ports.

6. The automatic turning microbial inoculant fermenter of claim 1, wherein: and a feed supplement port is arranged on the tank cover.

7. The automatic turning microbial inoculant fermenter of claim 1, wherein: a plurality of barrier strips extending up and down along the side walls are fixed in the tank body.

8. The automatic turning microbial inoculant fermenter of claim 1, wherein: the tank body is provided with an air inlet, the air inlet is positioned at the lower end of the tank body, an upward extending air outlet blind pipe is fixed at the upper end of the lower shaft, air outlet holes are uniformly distributed on the side wall of the air outlet blind pipe, the lower shaft is in sealing fit with the bearing shaft sleeve, and an air passage for communicating the air inlet with the air outlet blind pipe is formed in the lower shaft and the bearing shaft sleeve.

9. The automatic turning microbial inoculant fermenter of claim 1, wherein: the lower side of the tank cover is provided with a defoaming device, and the defoaming device comprises a centrifugal turbine and a housing; the centrifugal turbine takes a rotary shaft sleeve as a wheel shaft, the rotary shaft sleeve is rotationally fixed on the upper shaft, and the upper end of the rotary shaft sleeve is fixed with a driven wheel; a driving wheel is fixedly arranged on the upper shaft in a rotating way, the driving wheel is in transmission connection with the upper shaft through a ratchet mechanism, and the driving wheel is in transmission connection with a driven wheel; the lower end of the housing is open, and the housing is fixed on the lower side of the tank cover and covers the centrifugal turbine.

10. The automatic turning microbial inoculant fermenter of claim 9, wherein: the lower side of the tank cover is fixedly provided with a vertically extending transmission shaft in a rotating mode, a first transmission wheel and a second transmission wheel are fixedly arranged on the transmission shaft, the first transmission wheel is in transmission fit with the driving wheel, and the second transmission wheel is in transmission fit with the driven wheel.