Dissolved oxygen self-feedback fermentation system for microbial inoculant production

Abstract

This invention discloses a dissolved oxygen self-feedback fermentation system for the production of microbial inoculants, relating to the field of microbial fermentation technology. It includes a tank and an air distributor installed at the bottom of the tank, as well as a guide tube fixedly installed inside the tank. A stirring rod penetrating the guide tube is installed at the center of the tank. The stirring rod is equipped with multi-stage pusher blades and an airflow dispersion component elastically fitted to the bottom of the stirring rod. An air distribution net is slidably installed inside the guide tube between the multi-stage pusher blades and the airflow dispersion component. A transmission kit is fitted outside the stirring rod, with its top end abutting against the top surface of the guide tube and its bottom end connected to the airflow dispersion component. When the air distribution net rises and falls due to the flow rate of the air distributor, the transmission kit drives the airflow dispersion component to move in the opposite direction. This invention disperses air bubbles passing through the guide tube using an air distribution net, maintaining a stable dissolved oxygen concentration inside the tank and creating a constant growth and metabolic environment for the microorganisms.

Description

Technical Field

[0001] This invention relates to the field of microbial fermentation technology, specifically to a dissolved oxygen self-feedback fermentation system for the production of microbial agents. Background Technology

[0002] Microbial inoculants are mostly prepared by fermentation of aerobic strains. The growth, reproduction and synthesis of metabolites of the microorganisms depend on a sufficient and stable supply of dissolved oxygen. The dissolved oxygen efficiency and oxygen supply uniformity directly determine the number of viable cells, the spore conversion rate and the overall quality of the inoculant. They are the core control indicators for fermentation production. Generally, microbial inoculant fermentation systems rely on unidirectional aeration by an air distributor at the bottom of the tank, combined with a fixed stirring paddle to achieve gas-liquid mixing, thereby completing the transfer of dissolved oxygen.

[0003] The existing patent application, with publication number CN115074208A and publication date of September 20, 2022, is titled "A Stirred Airlift Fermenter and System." This patent includes a stirred airlift fermenter and an ethanol collection device. The stirred airlift fermenter comprises an outer wall component, a guide tube component, and a rotary jet device. This stirred airlift fermenter is an internal circulation reactor with a central air intake. During fermentation, a low stirring speed helps to further break up and disperse the bubbles, promoting gas-liquid mass transfer. Furthermore, the forced circulation provided by the four rotary nozzles and the single-stage propulsion agitator in the guide tube further enhances the gas-liquid mixing effect, allowing the microorganisms to fully utilize the biomass syngas, thereby increasing ethanol production. The entire system can simultaneously achieve continuous fermentation of biomass syngas to produce ethanol and the separation, purification, and collection of ethanol, showing promising application prospects in the biomass syngas fermentation ethanol production industry.

[0004] The above application has shortcomings. Although the sprayed bubbles are dispersed by stirring, the bubbles near the air outlet are still prone to quickly agglomerate and grow larger. The large bubbles rise quickly and have a short contact time with the fermentation liquid. The aeration flow rate and stirring action of the traditional system are independent of each other, and it is impossible to dynamically adjust the gas distribution and dispersion state according to the actual aeration volume. When the aeration flow rate increases, the bubbles are prone to local accumulation and gas-liquid mixing disorder. When the aeration flow rate decreases, the bubble distribution is sparse, the oxygen supply is insufficient, the dissolved oxygen concentration is difficult to maintain a stable level, and the sprayed airflow is difficult to diffuse evenly to the entire tank. The tank is prone to local over-oxygenation and local under-oxygenation. Summary of the Invention

[0005] The purpose of this invention is to provide a dissolved oxygen self-feedback fermentation system for the production of microbial inoculants, in order to overcome the shortcomings of the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A dissolved oxygen self-feedback fermentation system for the production of microbial inoculants includes a tank and an air distributor installed at the bottom of the tank. It also includes a guide tube fixedly installed inside the tank, with a stirring rod penetrating the guide tube at the center of the tank. The stirring rod is equipped with multi-stage pusher blades and an airflow dispersion component elastically fitted to the bottom of the stirring rod. Inside the guide tube, an air distribution net is slidably installed between the multi-stage pusher blades and the airflow dispersion component. A transmission kit is fitted outside the stirring rod, with its top end abutting against the top surface of the guide tube and its bottom end connected to the airflow dispersion component. When the air distribution net rises and falls due to the airflow rate of the air distributor, the transmission kit drives the airflow dispersion component to move in the opposite direction, while simultaneously, the transmission kit intermittently pushes the air distribution net downwards.

[0007] Preferably, a dissolved oxygen electrode is inserted into one side of the tank, and a variable frequency motor connected to a stirring rod is installed on the top of the tank. The controller adjusts the variable frequency motor and the air distributor based on the dissolved oxygen value of the dissolved oxygen electrode.

[0008] Preferably, the multi-stage pusher includes a connecting sleeve coaxially sleeved on the stirring rod, and multiple pusher blades are axially distributed along the outer edge of the connecting sleeve, and the multiple pusher blades are all located inside the guide tube.

[0009] Preferably, the airflow dispersion component includes a connecting sleeve that is vertically slidably sleeved at the bottom of the stirring rod, a buffer spring is installed inside the connecting sleeve and between it and the stirring rod, and an airflow distribution paddle is installed outside the connecting sleeve.

[0010] Preferably, the outer side of the air distribution net has multiple sliders distributed in a ring, and the inner wall of the guide tube has a vertical groove that matches the slider, and a through hole is formed in the groove.

[0011] Preferably, the transmission assembly includes a transmission sleeve that is vertically slidably sleeved on the outside of the stirring rod and an adjustment sleeve that is rotatably nested on the stirring rod. The top of the transmission sleeve passes through an air distribution net and is fixedly connected to an abutting toothed ring. The top surface of the air distribution net has a plurality of abutting protrusions that abut against the abutting toothed ring in an annular arrangement.

[0012] Preferably, the adjusting sleeve is located between the transmission sleeve and the connecting sleeve. The adjusting sleeve has a plurality of upper inclined grooves and lower inclined grooves symmetrical to the upper inclined grooves distributed in a ring. The inner wall of the transmission sleeve is fixedly connected to a plurality of transmission pins that are respectively inserted into each of the upper inclined grooves. The inner wall of the connecting sleeve is fixedly connected to a plurality of insertion pins that are respectively inserted into the lower inclined grooves.

[0013] Preferably, the stirring rod is equipped with a defoaming plate above the guide tube, and a guide cone is installed at the bottom of the defoaming plate.

[0014] Preferably, the bottom surface of the defoaming disc is slidably equipped with a plurality of defoaming paddles arranged in a ring, and the defoaming disc is equipped with a plurality of counter-centrifugal transmission components that are connected to each defoaming paddle. When the centrifugal force increases, the counter-centrifugal transmission components drive the defoaming paddles to overcome the centrifugal force and retract.

[0015] Preferably, the reverse centrifugal transmission assembly includes a counterweight block slidably installed in the defoaming disc, a top spring for pushing the counterweight block towards the center is installed in the defoaming disc, a pulley is rotatably installed at the bottom of the defoaming disc, and a traction rope passing around the pulley is connected between the counterweight block and the defoaming paddle.

[0016] In the above technical solution, an air distribution net is used to disperse air bubbles passing through the guide tube. When the air intake of the air distributor increases, it pushes the air distribution net upward. Simultaneously, the air distribution net moves downward via a transmission kit, bringing the airflow dispersion component closer to the air distributor's outlet. This close-range dispersion and diversion of the ejected airflow prevents large-volume airflow from concentrating and causing rapid bubble coalescence. When the intake volume decreases and the airflow impact weakens, the air distribution net falls back to its original position under the gravity of the transmission kit. Simultaneously, the transmission kit moves the airflow dispersion component upward, away from the air distributor's outlet, adapting to the dispersion requirements of small-volume airflows and ensuring airflow... Uniform diffusion ensures a stable dissolved oxygen concentration within the tank, creating a constant growth and metabolic environment for the microorganisms. The airflow dispersion component moves up and down with the air intake, working in conjunction with the rotational motion driven by the stirring rod to break up the airflow ejected from the air distributor in multiple stages, dispersing large bubbles into uniform and fine microbubbles. This prolongs the residence time of bubbles in the fermentation broth, increases the gas-liquid contact area and dissolved oxygen transfer rate. Simultaneously, the transmission kit intermittently pushes the air distribution net, preventing clogging, ensuring smooth airflow, and further dispersing the airflow to optimize air distribution uniformity. Dissolved oxygen requirements can be met without blindly increasing the air intake and stirring speed, thus reducing fermentation energy consumption.

[0017] It should be understood that the foregoing general description and the following detailed description are exemplary and illustrative only, and are not intended to limit this disclosure.

[0018] This application provides an overview of various implementations or examples of the technology described in this disclosure, and is not a full disclosure of the entire scope or all features of the disclosed technology. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0020] Figure 1This is a schematic diagram of the overall structure of a dissolved oxygen self-feedback fermentation system for the production of microbial inoculants according to the present invention; Figure 2 This is a cross-sectional view of the overall structure of a dissolved oxygen self-feedback fermentation system for the production of microbial inoculants according to the present invention. Figure 3 This is a schematic diagram of the internal structure of a tank in a dissolved oxygen self-feedback fermentation system for the production of microbial inoculants according to the present invention. Figure 4 This is a schematic diagram showing the connection between the stirring rod and the airflow dispersion component in a dissolved oxygen self-feedback fermentation system for the production of microbial inoculants according to the present invention. Figure 5 This is a schematic diagram of the flow guide tube and aeration net in a dissolved oxygen self-feedback fermentation system for the production of microbial inoculants according to the present invention; Figure 6 This is a schematic diagram of the airflow dispersion component and transmission kit in a dissolved oxygen self-feedback fermentation system for the production of microbial inoculants according to the present invention. Figure 7 This is a schematic diagram showing the connection between the stirring rod and the regulating sleeve in a dissolved oxygen self-feedback fermentation system for the production of microbial inoculants according to the present invention. Figure 8 This is a schematic diagram showing the connection of an airflow dispersion component and a regulating kit in a dissolved oxygen self-feedback fermentation system for the production of microbial inoculants according to the present invention; Figure 9 This is a schematic diagram of the reverse centrifugal transmission component in a dissolved oxygen self-feedback fermentation system for the production of microbial inoculants according to the present invention.

[0021] Explanation of reference numerals in the attached figures: 1. Tank body; 101. Dissolved oxygen electrode; 2. Air distributor; 3. Flow guide tube; 301. Air distribution net; 302. Sliding block; 303. Slide groove; 304. Through hole; 305. Abutment protrusion; 4. Stirring rod; 401. Variable frequency motor; 5. Multi-stage pusher; 501. Connecting sleeve; 502. Pusher blade; 6. Airflow dispersion assembly; 601. Connecting sleeve; 602. Buffer spring; 60 3. Airflow distribution propeller; 604. Insertion post; 7. Transmission assembly; 701. Transmission sleeve; 702. Adjustment sleeve; 703. Abutment toothed ring; 704. Upper inclined groove; 705. Lower inclined groove; 706. Transmission post; 8. Defoaming disc; 801. Guide cone; 802. Defoaming propeller; 9. Counter-centrifugal transmission assembly; 901. Counterweight; 902. Top spring; 903. Pulley; 904. Traction rope. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0023] Please see Figure 1-9 This invention provides a dissolved oxygen self-feedback fermentation system for the production of microbial agents, comprising a tank 1 and an air distributor 2 installed at the bottom of the tank 1, and a guide tube 3 fixedly installed inside the tank 1. A stirring rod 4 penetrating the guide tube 3 is installed at the center of the tank 1. A multi-stage pusher 5 is installed on the stirring rod 4. An airflow dispersion component 6 is elastically sleeved on the bottom end of the stirring rod 4. An air distribution net 301 is slidably installed inside the guide tube 3 between the multi-stage pusher 5 and the airflow dispersion component 6. A transmission kit 7 is sleeved on the outside of the stirring rod 4, with its top end abutting against the top surface of the guide tube 3 and its bottom end being connected to the airflow dispersion component 6. When the air distribution net 301 rises and falls due to the flow rate of the air distributor 2, the transmission kit 7 drives the airflow dispersion component 6 to move in the opposite direction. At the same time, the transmission kit 7 intermittently pushes the air distribution net 301 downward.

[0024] Specifically, the air distributor 2 is fixedly installed at the bottom of the tank 1 to introduce sterile air into the fermentation broth inside the tank 1. The guide tube 3 is vertically fixed inside the tank 1 and is coaxial with the tank 1. Both the upper and lower ends of the guide tube 3 are open, allowing the fermentation broth and airflow to circulate inside and outside the tube. The multi-stage pusher paddles 5 are evenly arranged along the axial direction of the stirring rod 4 and are located inside the guide tube 3. As the stirring rod 4 rotates, the multi-stage pusher paddles 5 can drive the fermentation broth to form a circulation between the guide tube 3 and the tank 1, while also helping to disperse air bubbles, improving the gas-liquid mixing efficiency and providing auxiliary power for the airflow mixing and circulation. The airflow dispersion component 6 can also be adjusted accordingly. The stirring rod 4 rotates synchronously to break up the airflow. The surface of the air distribution mesh 301 is uniformly covered with fine pores to disperse the rising airflow and prevent large bubbles from rising directly. The air distribution mesh 301 can float up and down according to the airflow rate of the air distributor 2. When the air distribution mesh 301 rises due to airflow impact, it drives the airflow dispersion component 6 to move in the opposite direction via the transmission kit 7. That is, when the air distribution mesh 301 rises, the airflow dispersion component 6 moves down; when the air distribution mesh 301 falls, the airflow dispersion component 6 moves up. Employing a self-feedback airflow dynamic adjustment mechanism, the lifting and lowering displacement of the air distribution mesh 301 is entirely determined by the airflow rate of the air distributor 2. When the intake volume increases and the airflow impact force becomes stronger, the upward airflow thrust overcomes the gravity of the transmission kit 7, pushing the air distribution net 301 to slide upward along the guide tube 3. The air distribution net 301 transmits displacement power through the transmission kit 7, causing the airflow dispersion component 6 to move downward in the opposite direction, close to the air outlet of the air distributor 2, and breaking up the concentrated airflow that has just been ejected at close range and with high intensity, preventing the formation of large bubbles from the source, and avoiding uneven gas-liquid mixing and a sharp drop in dissolved oxygen transfer efficiency caused by a large flow of airflow. When the intake volume decreases and the airflow impact force weakens, the air distribution net 301 loses sufficient upward thrust, and under the action of its own gravity, it slides upward along the transmission kit 7. The airflow distribution device 6 smoothly returns to its initial position. At the same time, the transmission kit 7 drives the airflow dispersion component 6 to reset upwards, away from the air outlet of the air distributor 2, to avoid excessive obstruction of the small flow of air and ensure that the small flow of air can be evenly diffused. This adapts to the dissolved oxygen supply requirements under low oxygen demand conditions and prevents the dissolved oxygen concentration from being too low and affecting the metabolism of the microorganisms. During operation, the transmission kit 7 will also intermittently push the air distribution net 301 downwards to achieve a small vibration of the air distribution net 301. This can prevent the microorganisms and impurities in the fermentation liquid from clogging the ventilation holes of the air distribution net 301 and ensure smooth airflow. It can also help to disperse the airflow and further improve the uniformity of air distribution.

[0025] Compared with the prior art, this embodiment of the invention disperses bubbles passing through the guide tube 3 by setting an air distribution net 301. When the air intake of the air distributor 2 increases, it pushes the air distribution net 301 upward. As the air distribution net 301 moves upward, the transmission kit 7 drives the airflow dispersion component 6 to move downward and approach the air outlet of the air distributor 2. This disperses and diverts the ejected airflow at close range, preventing the concentrated jetting of large-volume airflow and the rapid coalescence of bubbles. When the air intake decreases and the airflow impact weakens, the air distribution net 301 falls back to its original position under the gravity of the transmission kit 7. Simultaneously, the transmission kit 7 drives the airflow dispersion component 6 to move upward, away from the air outlet of the air distributor 2, adapting to the dispersion of small-volume airflow. To meet the oxygen demand, the airflow dispersion component 6 can move up and down with the air intake, and together with the rotation driven by the stirring rod 4, it breaks up the airflow sprayed from the air distributor 2 in multiple stages, breaking large bubbles into uniform and fine microbubbles, prolonging the residence time of bubbles in the fermentation liquid, increasing the gas-liquid contact area and dissolved oxygen transfer rate. At the same time, the transmission component 7 intermittently pushes the air distribution net 301, which can not only prevent the air distribution net 301 from being blocked and ensure smooth airflow, but also help to disperse the airflow and further optimize the uniformity of air distribution. The dissolved oxygen demand can be met without blindly increasing the air intake and stirring speed, thus reducing fermentation energy consumption.

[0026] In a further embodiment of the present invention, a dissolved oxygen electrode 101 is inserted into one side of the tank body 1, and a variable frequency motor 401 connected to the stirring rod 4 is installed on the top of the tank body 1. The controller regulates the variable frequency motor 401 and the air distributor 2 based on the dissolved oxygen value of the dissolved oxygen electrode 101. Specifically, the dissolved oxygen electrode 101 monitors the dissolved oxygen concentration of the fermentation liquid in the tank in real time and transmits the data to the controller. The controller dynamically adjusts the output speed of the variable frequency motor 401 and the air intake flow of the air distributor 2 according to a preset dissolved oxygen threshold range. When the dissolved oxygen electrode 101 detects that the dissolved oxygen value is lower than the set lower limit, the controller immediately issues a command to improve the dissolved oxygen concentration. The high-frequency motor 401's rotation speed causes the stirring rod 4 to drive the multi-stage pusher 5 and airflow dispersion component 6 to rotate at a higher speed, enhancing the stirring intensity and bubble breaking effect of the fermentation broth. On the other hand, it increases the air intake of the air distributor 2, increasing the oxygen supply. Through the synergistic effect of the two, the dissolved oxygen concentration is quickly increased to a suitable range. When the dissolved oxygen value is higher than the set upper limit, the controller reduces the speed of the high-frequency motor 401 and reduces the air intake of the air distributor 2 to avoid energy waste and the adverse effects of over-aeration on cell growth. This achieves precise closed-loop control of dissolved oxygen concentration, ensuring that the fermentation process is always in the optimal dissolved oxygen environment.

[0027] In a further embodiment of the present invention, the multi-stage pusher 5 includes a connecting sleeve 501 coaxially sleeved on the stirring rod 4. Multiple pusher blades 502 are axially distributed along the outer edge of the connecting sleeve 501, and all multiple pusher blades 502 are located inside the guide tube 3. Specifically, the connecting sleeve 501 is sleeved with the stirring rod 4 through a keyway to ensure that the stirring rod 4 can synchronously drive the pusher blades 502 to rotate when it rotates. The multiple pusher blades 502 are evenly distributed along the axial direction of the connecting sleeve 501. When the stirring rod 4 drives the pusher blades 502 to rotate, the blades located inside the guide tube 3 generate axial thrust on the fermentation liquid, pushing the fermentation liquid to flow upward from the bottom of the guide tube 3. After reaching the top of the guide tube 3, it diffuses to the surroundings and then flows back downward along the annular space between the guide tube 3 and the inner wall of the tank 1, forming a stable internal circulation flow field. The multi-stage pusher can effectively enhance the stirring uniformity of the fermentation liquid, avoid the occurrence of stirring dead zones in local areas, and promote the dispersion and dissolution of bubbles in the fermentation liquid, thereby improving the dissolved oxygen transfer efficiency.

[0028] In a further embodiment of the present invention, the airflow dispersion component 6 includes a connecting sleeve 601 vertically slidably sleeved at the bottom of the stirring rod 4. A buffer spring 602 is installed inside the connecting sleeve 601 and between it and the stirring rod 4, and an airflow equalization paddle 603 is installed outside the connecting sleeve 601. Specifically, the stirring rod 4 drives the airflow equalization paddle 603 to rotate synchronously through the connecting sleeve 601 connected to its keyway. When the connecting sleeve 601 rotates with the stirring rod 4, the airflow equalization paddle 603 forms a shearing force on the airflow ejected from the air distributor 2 during rotation, cutting larger bubbles into smaller bubbles. At the same time, the centrifugal force generated by the rotation of the paddle can throw the bubbles out in all directions, promoting the uniform diffusion of bubbles in the fermentation liquid. The buffer spring 602 provides an upward elastic support force for the connecting sleeve 601, so that the airflow dispersion component 6 maintains its initial height when not in operation. The buffer spring 602 can also absorb the impact force when the airflow dispersion component 6 moves up and down, avoiding wear caused by rigid collisions between components and extending the service life of the equipment.

[0029] In a further embodiment of the present invention, a plurality of sliders 302 are distributed in a ring on the outer side of the aeration net 301, and a vertical groove 303 matching the sliders 302 is provided on the inner wall of the guide tube 3, and a through hole 304 is provided through the groove 303. Specifically, the sliders 302 and the groove 303 slide together to ensure that the aeration net 301 can only move vertically up and down along the inner wall of the guide tube 3, so as to avoid the aeration net 301 from shifting or rotating under the impact of airflow, and to ensure the stability and reliability of the movement of the aeration net 301. The through hole 304 allows the fermentation liquid inside and outside the guide tube 3 to be further exchanged through the through hole 304, balance the pressure difference inside and outside the guide tube 3, and avoid the formation of local pressure fluctuations in the guide tube 3 due to the rise and fall of the aeration net 301, which would affect the normal circulation of the fermentation liquid. At the same time, the guiding effect of the through hole 304 can help the fermentation liquid form an orderly up and down circulation in the guide tube 3, and improve the gas-liquid mixing effect.

[0030] In a further embodiment of the present invention, the transmission assembly 7 includes a transmission sleeve 701 vertically slidably sleeved outside the stirring rod 4 and an adjusting sleeve 702 rotatably nested on the stirring rod 4. The top of the transmission sleeve 701 passes through the air distribution mesh 301 and is fixedly connected to an abutting toothed ring 703. The top surface of the air distribution mesh 301 has a plurality of abutting protrusions 305 arranged in a ring to abut against the abutting toothed ring 703. Specifically, when the stirring rod 4 drives the adjusting transmission sleeve 701 to rotate, since the air distribution mesh 301 cannot rotate with the stirring rod 4, the abutting toothed ring 703 on the transmission sleeve 701 and the plurality of abutting protrusions 305 on the air distribution mesh 301 periodically engage and disengage. When the two disengage, the abutting protrusions... 305 pushes up the abutting toothed ring 703, pushing the aeration net 301 upward against gravity. When the two mesh, the aeration net 301 falls back under its own weight and the pressure of the transmission kit 7. During this process, the intermittent abutting engagement between the abutting toothed ring 703 and the abutting protrusion 305 realizes the small up-and-down vibration of the aeration net 301. This vibration can not only effectively remove the bacteria and impurities attached to the surface of the aeration net 301 and prevent the ventilation holes from being blocked, but also further disturb the rising airflow through the vibration of the aeration net 301, making the airflow more evenly dispersed and avoiding the accumulation of local bubbles. Thus, without increasing the additional power, the gas-liquid mass transfer efficiency is improved, providing a stable ventilation environment for the efficient fermentation of microbial agents.

[0031] In a further embodiment of the present invention, the adjusting sleeve 702 is located between the transmission sleeve 701 and the connecting sleeve 601. The adjusting sleeve 702 has a plurality of upper inclined grooves 704 and lower inclined grooves 705 symmetrically distributed on its annular surface. A plurality of transmission posts 706, each inserted into one of the upper inclined grooves 704, are fixedly connected to the inner wall of the transmission sleeve 701. A plurality of insertion posts 604, each inserted into one of the lower inclined grooves 705, are fixedly connected to the inner wall of the connecting sleeve 601. Specifically, when the air distribution net 301 is subjected to… As the airflow impacts and slides upward along the guide tube 3, the air distribution net 301 drives the transmission sleeve 701 to rise synchronously. The transmission column 706 on the inner wall of the transmission sleeve 701 slides upward along the upper inclined groove 704 of the adjusting sleeve 702. Since the upper inclined groove 704 and the axis of the adjusting sleeve 702 form a certain angle, the transmission column 706 will generate a circumferential rotational force on the adjusting sleeve 702 during the sliding process, causing the adjusting sleeve 702 to rotate around the stirring rod 4. When the adjusting sleeve 702 rotates, its lower inclined groove 705... The insert post 604 on the inner wall of the connecting sleeve 601 slides relative to the upper inclined groove 704. The inclination direction of the lower inclined groove 705 is opposite to that of the upper inclined groove 704. Therefore, when the insert post 604 slides in the inclined groove, it will drive the connecting sleeve 601 to move downward along the stirring rod 4, thereby causing the airflow dispersion component 6 to move down synchronously and approach the air distributor 2. Conversely, when the air distribution net 301 falls downward under the action of gravity, the transmission sleeve 701 moves down accordingly, and the transmission post 706 slides in the opposite direction along the upper inclined groove 704, driving the adjusting sleeve 702 to rotate in the opposite direction. The lower inclined groove 705 pulls the connecting sleeve 601 upward to reset through the insert post 604, realizing the upward movement of the airflow dispersion component 6. The linear motion of the air distribution net 301 is converted into the rotational motion of the adjusting sleeve 702, and further converted into the reverse linear motion of the airflow dispersion component 6. This realizes the linkage adjustment of the airflow dispersion component 6 and the air distribution net 301, ensuring that the two can respond quickly and work together when the air intake changes, and always maintain the best bubble breaking and dispersion effect.

[0032] In a further embodiment of the present invention, a defoaming plate 8 is installed above the guide tube 3 on the stirring rod 4, and a guide cone 801 is installed at the bottom of the defoaming plate 8. Specifically, the guide cone 801 has an inverted cone structure that is wider at the top and narrower at the bottom. Its cone surface can guide the foam that rises to the top of the tank 1 to the edge of the defoaming plate 8, so as to avoid the foam from accumulating in the central area of ​​the top of the tank, which facilitates rapid dispersion and defoaming, and also allows the fermentation liquid to flow smoothly from the top opening of the guide tube 3 to the outside.

[0033] In a further embodiment of the present invention, a plurality of defoaming paddles 802 arranged in a ring are slidably mounted on the bottom surface of the defoaming disc 8. A plurality of counter-centrifugal transmission components 9 are mounted on the defoaming disc 8 and are connected to each defoaming paddle 802. When the centrifugal force increases, the counter-centrifugal transmission components 9 drive the defoaming paddles 802 to overcome the centrifugal force and retract. When the centrifugal force decreases, the defoaming paddles 802 extend under the action of centrifugal force. Specifically, when the stirring rod 4 drives the defoaming disc 8 to rotate at high speed, the centrifugal block moves outward under the action of centrifugal force, and the counter-centrifugal transmission components 9 drive the defoaming paddles 802 to gradually retract to the bottom of the defoaming disc 8. Even if the paddle blades retract slightly, their terminal linear velocity is still sufficient to efficiently break up the foam, and the high-flow-rate fermentation liquid can also quickly impact the defoaming disc 8. At this time, excessively long paddle blades are not required. By appropriately retracting the blades at high speeds, unnecessary power consumption and side effects can be significantly reduced while maintaining sufficient defoaming linear speed, achieving a balance between energy efficiency and protection. When the dissolved oxygen value measured by the dissolved oxygen electrode 101 is too high, causing the rotation speed of the stirring rod 4 to decrease, the centrifugal force decreases. The defoaming blade 802 extends under the action of centrifugal force, which can significantly increase the linear speed and expand the sweeping area, capturing foam over a larger range and compensating for insufficient rotation speed. The surface of the defoaming blade 802 is uniformly distributed with serrated defoaming teeth, which can efficiently cut the foam and disrupt its stability during rotation. At the same time, the centrifugal force generated by the blade rotation throws the broken foam droplets toward the tank wall, which then flows back into the fermentation liquid along the wall, reducing the risk of foam overflow and ensuring the stable progress of the fermentation process.

[0034] In a further embodiment of the present invention, the reverse centrifugal transmission assembly 9 includes a counterweight 901 slidably mounted in the defoaming disc 8. A top spring 902 is installed inside the defoaming disc 8 to push the counterweight 901 toward the center. A pulley 903 is rotatably mounted at the bottom of the defoaming disc 8. A traction rope 904, passing around the pulley 903, connects the counterweight 901 and the defoaming paddle 802. Specifically, when the defoaming disc 8 rotates with the stirring rod 4, the counterweight 901 slides toward the edge of the defoaming disc 8 under the action of centrifugal force, overcoming the elastic force of the top spring 902. The traction rope 904 changes the direction of the force through the pulley 903, pulling the defoaming paddle 802 toward the center of the defoaming disc 8. When the stirring speed decreases and the centrifugal force weakens, the top spring 902 pushes the counterweight 901 back to the center, and the traction rope 904 loosens. At this time, the defoaming paddle 802 can extend outward under the action of a smaller centrifugal force, realizing the dynamic adjustment of the length of the defoaming paddle 802 with the speed. This allows the defoaming system to adaptively adjust the extension length of the paddle according to the changes in the stirring speed during fermentation. While ensuring the defoaming effect, it minimizes energy consumption, avoids power waste caused by excessively long paddles at high speeds and excessive shearing of the fermentation liquid, and can also ensure sufficient defoaming coverage by extending the paddle at low speeds, effectively dealing with foam generation at different fermentation stages.

[0035] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A dissolved oxygen self-feedback fermentation system for the production of microbial inoculants, comprising a tank (1) and an air distributor (2) installed at the bottom of the tank (1), characterized in that, Also includes: The guide tube (3) is fixedly installed inside the tank (1), and a stirring rod (4) that penetrates the guide tube (3) is installed in the center of the tank (1). The stirring rod (4) is equipped with a multi-stage pusher (5). An airflow dispersion component (6) is elastically sleeved at the bottom of a stirring rod (4), and an air distribution net (301) is slidably installed inside the guide tube (3) between the multi-stage pusher (5) and the airflow dispersion component (6). The transmission kit (7) is sleeved outside the stirring rod (4), and its top end abuts against the top surface of the guide tube (3), and its bottom end is connected to the airflow dispersion component (6) in a transmission manner; When the air distribution net (301) rises and falls due to the flow rate of the air distributor (2), the airflow dispersion component (6) is driven to move in the opposite direction by the transmission kit (7), and at the same time the transmission kit (7) intermittently pushes the air distribution net (301) downward.

2. The dissolved oxygen self-feedback fermentation system for microbial agent production according to claim 1, characterized in that, A dissolved oxygen electrode (101) is inserted into one side of the tank (1), and a variable frequency motor (401) connected to the stirring rod (4) is installed on the top of the tank (1). The controller adjusts the variable frequency motor (401) and the air distributor (2) by the dissolved oxygen value of the dissolved oxygen electrode (101).

3. The dissolved oxygen self-feedback fermentation system for microbial agent production according to claim 1, characterized in that, The multi-stage pusher (5) includes a connecting sleeve (501) coaxially sleeved on the stirring rod (4), and multiple pusher blades (502) are distributed along the outer axial direction of the connecting sleeve (501), and the multiple pusher blades (502) are all located inside the guide tube (3).

4. The dissolved oxygen self-feedback fermentation system for microbial agent production according to claim 1, characterized in that, The airflow dispersion component (6) includes a connecting sleeve (601) that is vertically slidably sleeved at the bottom of the stirring rod (4). A buffer spring (602) is installed inside the connecting sleeve (601) and between it and the stirring rod (4). An airflow distribution paddle (603) is installed outside the connecting sleeve (601).

5. The dissolved oxygen self-feedback fermentation system for microbial agent production according to claim 1, characterized in that, The air distribution net (301) has multiple sliders (302) distributed in a ring on the outer side. The inner wall of the guide tube (3) is vertically provided with a groove (303) that matches the slider (302), and a through hole (304) is provided in the groove (303).

6. The dissolved oxygen self-feedback fermentation system for microbial agent production according to claim 4, characterized in that, The transmission assembly (7) includes a transmission sleeve (701) that is vertically slidably sleeved outside the stirring rod (4) and an adjustment sleeve (702) that is rotatably nested on the stirring rod (4). The top of the transmission sleeve (701) passes through the air distribution net (301) and is fixedly connected to an abutting toothed ring (703). The top surface of the air distribution net (301) has a number of abutting protrusions (305) that abut against the abutting toothed ring (703).

7. A dissolved oxygen self-feedback fermentation system for the production of microbial inoculants according to claim 6, characterized in that, The adjusting sleeve (702) is located between the transmission sleeve (701) and the connecting sleeve (601). The adjusting sleeve (702) has a plurality of upper inclined grooves (704) and lower inclined grooves (705) symmetrical to the upper inclined grooves (704) distributed in a ring. The inner wall of the transmission sleeve (701) is fixedly connected to a plurality of transmission pins (706) that are respectively inserted into each of the upper inclined grooves (704). The inner wall of the connecting sleeve (601) is fixedly connected to a plurality of insertion pins (604) that are respectively inserted into the lower inclined grooves (705).

8. The dissolved oxygen self-feedback fermentation system for microbial agent production according to claim 1, characterized in that, The stirring rod (4) is equipped with a defoaming plate (8) above the flow guide tube, and a flow guide cone (801) is installed at the bottom of the defoaming plate (8).

9. A dissolved oxygen self-feedback fermentation system for the production of microbial inoculants according to claim 8, characterized in that, The bottom surface of the defoaming disc (8) is slidably equipped with a plurality of defoaming paddles (802) arranged in a ring. The defoaming disc (8) is equipped with a plurality of reverse centrifugal transmission components (9) that are connected to each defoaming paddle (802). When the centrifugal force increases, the reverse centrifugal transmission components (9) drive the defoaming paddles (802) to overcome the centrifugal force and retract.

10. A dissolved oxygen self-feedback fermentation system for the production of microbial inoculants according to claim 9, characterized in that, The reverse centrifugal transmission assembly (9) includes a counterweight (901) slidably installed in the defoaming disc (8), a top spring (902) for pushing the counterweight (901) towards the center is installed in the defoaming disc (8), a pulley (903) is rotatably installed at the bottom of the defoaming disc (8), and a traction rope (904) is connected between the counterweight (901) and the defoaming paddle (802) and passes around the pulley (903).

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