Rotary impeller, aeration device and rotary impeller aeration bioreactor

Abstract

The invention provides a rotary impeller which comprises a bottom plate and a cover plate which are vertically spaced and coaxially arranged, a gas-liquid mixing chamber and a gas-liquid runner chamber are sequentially divided between the cover plate and the bottom plate from inside to outside with the axis of the cover plate and the bottom plate as the center, and a gas guide structure extends into the gas-liquid mixing chamber. A plurality of liquid inlets are formed in the bottom plate in the range of the gas-liquid mixing chamber, a gas-liquid outlet is formed between the bottom plate and the outer edge of the cover plate, and a plurality of gas-liquid flow channels which are uniformly distributed around the axis are formed in the gas-liquid flow channel chamber through separation of a plurality of partition plates; and one or more of a shunting and pipe shrinking structure, a secondary acceleration and expansion structure and a micro-channel mixed shearing structure are arranged in each gas-liquid flow channel. The invention also provides an aeration device and a bioreactor comprising the rotary impeller. According to the scheme, fresh gas reaches the rotating impeller to generate microbubbles, the structure is simple, and the cost is low; the method is not limited to bioreactors, and can also be used for reactions of general gas-liquid two-phase and gas-liquid-solid three-phase systems.

Description

Technical Field

[0001] The invention belongs to the technical field of biochemical engineering, and in particular relates to a rotary impeller, an aeration device and a rotary impeller aeration bioreactor. Background Art

[0002] Multiphase reactors are widely used in various industries, especially in the biochemical industry. The efficiency of multiphase reactors is related to the quality and cost of products, and sometimes directly reflects the success of the process route. At present, there are many types of multiphase reactors, such as Venturi reactors, trickle bed reactors, bubble reactors, supergravity bed reactors, microchannel reactors, etc. Their common purpose is to increase the mass transfer efficiency between phases.

[0003] Due to its particularity, the structure and requirements of multiphase bioreactors are higher. For multiphase reactions such as gas-liquid, gas-liquid-solid, etc., designers must consider both the mass transfer efficiency and the aseptic requirements of the reactor. Therefore, most biological reactions currently have low mass transfer efficiency in gas-liquid and gas-liquid-solid. However, since the advent of micro-interface mass transfer enhancement technology, a revolution has been set off in bioreactors. New reactions such as Venturi microbubble reactors, supergravity field microbubble reactors, dynamic membrane microbubble reactors, and microchannel reactors have emerged to solve the mass transfer efficiency of gas-liquid and gas-liquid-solid. However, some new reactors (such as Venturi microbubble reactors, supergravity field microbubble reactors, and microchannel reactors) are affected by the requirements for pure microbial culture, and their application is limited.

[0004] At present, most bioreactors use aeration methods such as dynamic membrane aeration and multi-layer shear microporous aeration, which have good effects. However, although dynamic membrane aeration can solve the blockage problem and increase the service life, the transmembrane pressure of the membrane will increase with the increase of operating time, thereby reducing the ventilation volume per unit membrane area, and also increasing the intake pressure and operating costs. Multi-layer shear microporous aeration uses multi-layer shear, which invisibly increases the motor power and increases the operating cost, and multi-layer shear is not suitable for shear-sensitive systems.

[0005] In summary, highly aerobic, C1 gas and biomass gas fermentation systems urgently need to design a bioreactor that can produce microbubbles, use multiple systems and operate aeration for a long time. Summary of the invention

[0006] In view of the above problems, the present invention provides a rotary impeller, an aeration device and a rotary impeller aeration bioreactor. Due to the unique built-in structure of the rotary impeller, different fermentation systems can select suitable impeller structures, which greatly improves its application range. The present invention also provides an aeration device with such a rotary impeller and a rotary impeller aeration bioreactor using such an aeration device. The reactor uses an external power to control the rotation speed of the rotary impeller, so that the rotation speed of the rotary impeller can be flexibly adjusted for different systems; the reactor has the characteristics of good gas-liquid mixing effect, simple structure, convenient maintenance, flexible operation, etc.

[0007] To achieve the above object, the present invention adopts the following technical solution: A rotating impeller comprises a bottom plate and a cover plate spaced apart and coaxially arranged up and down, wherein the space between the cover plate and the bottom plate is divided into a gas-liquid mixing chamber and a gas-liquid flow channel chamber from the inside to the outside with its axis as the center, an air guide structure extends into the gas-liquid mixing chamber, a plurality of liquid inlets are arranged on the bottom plate within the range of the gas-liquid mixing chamber, a gas-liquid outlet is formed between the outer edges of the bottom plate and the cover plate, a plurality of gas-liquid flow channels evenly distributed around the axis are formed in the gas-liquid flow channel chamber by a plurality of partitions, and one or more of a diversion and contraction structure, a secondary acceleration and expansion structure, and a microchannel mixing shear structure are arranged in each of the gas-liquid flow channels.

[0008] Furthermore, a liquid guide wheel is provided at the inner bottom of the gas-liquid mixing chamber, and the liquid guide wheel is penetrated and fixed at the lower end of the gas guide structure; the number of guide impellers on the liquid guide wheel is 4 or 6 or 8 or 12 or 16 or 24, preferably 6 or 8 or 12 or 16.

[0009] Furthermore, the rotating impeller also includes a core shaft seat formed in the middle of the upper end surface of the cover plate, and a mounting hole extending axially downward from the upper end surface of the core shaft seat to the lower end surface of the base plate, and the air guide structure is connected to the rotating impeller through the mounting hole; the axial height of the gas-liquid mixing chamber is greater than the axial height of the gas-liquid flow channel chamber.

[0010] Furthermore, the partition includes a plurality of first plane partitions and a plurality of second plane partitions, which are distributed in a circle with the axis as the center and are alternately arranged at equal intervals. The length of the first plane partition is greater than that of the second plane partition. The first plane partition penetrates the gas-liquid flow channel chamber in a radial direction, and the outer side surface of the second plane partition in the radial direction extends to the outer edge of the cover plate; two adjacent first plane partitions, the bottom plate and the cover plate form a gas-liquid flow channel, and a diverter and shrinkage tube structure and a secondary acceleration and expansion structure are arranged from the inside to the outside in the gas-liquid flow channel. The diverter and shrinkage tube structure is a crescent-shaped structural block with the concave surface facing the outside. The secondary acceleration and expansion structure consists of two first square bending blocks with the inner folded surface facing the outside and two second square bending blocks with the inner folded surface facing the outside. The two first square bending blocks and the two second square bending blocks are mirror-symmetrically arranged on both sides of the second plane partition, the first square bending block is located on the inner side of the second square bending block, and the outermost edge of the second square bending block is arranged adjacent to the outer edge of the cover plate.

[0011] Furthermore, the partition includes a plurality of first arc-shaped partitions uniformly distributed in a circle with the axis as the center, one end of the first arc-shaped partition is located at the outer edge of the cover plate, and the other end is located on the inner ring line of the gas-liquid flow channel chamber, and two adjacent first arc-shaped partitions, the bottom plate and the cover plate form a gas-liquid flow channel, and a diversion and reduction tube structure and a secondary acceleration and expansion structure are sequentially arranged in the gas-liquid flow channel from the inside to the outside, the diversion and reduction tube structure is an arrow-shaped structural block with the tip facing the inside, and the secondary acceleration and expansion structure is a triangular structural block with the tip facing the arrow-shaped structural block, and the outer side surface of the triangular structural block is located at the outer edge of the cover plate, and two shear blocks are mirror-imaged on the inner side surfaces of two adjacent first arc-shaped partitions.

[0012] Furthermore, the partition includes a plurality of V-shaped partitions which are evenly distributed in a circle with the axis as the center and have an inner angle greater than 90°, one end of the V-shaped partition is located at the outer edge of the cover plate, and the other end is located on the inner ring line of the gas-liquid flow channel chamber; two adjacent V-shaped partitions, the bottom plate and the cover plate form a gas-liquid flow channel, and two secondary acceleration and expansion structures are arranged in sequence from the inside to the outside in the gas-liquid flow channel, and the two secondary acceleration and expansion structures are two polygonal structural blocks of different shapes, and the two side ends of the two polygonal structural blocks along the extension direction of the gas-liquid flow channel are pointed.

[0013] Furthermore, the partition includes a plurality of second arc-shaped partitions uniformly distributed in a circle with the axis as the center, one end of the second arc-shaped partition is located at the outer edge of the cover plate, and the other end is located on the inner ring line of the gas-liquid flow channel chamber; a plurality of semi-heart-shaped grooves are evenly spaced on the side surfaces of the second arc-shaped partition along the arc direction, and the semi-heart-shaped grooves on the opposite sides of two adjacent second arc-shaped partitions are arranged opposite to each other, and the two adjacent second arc-shaped partitions, the bottom plate and the cover plate form a gas-liquid flow channel with a microchannel heart-shaped mixing shear structure.

[0014] An aeration device, characterized in that the aeration device includes a motor, a magnetic fluid seal, a hollow shaft and a rotating impeller, an air inlet is provided on the upper end side wall of the hollow shaft, the upper end of the hollow shaft is connected to an external air source through a magnetic fluid seal, the motor is connected to the hollow shaft through a coupling frame, the rotating impeller is the rotating impeller described in claims 1 to 7, the lower end of the hollow shaft is penetrated and fixed to the rotating impeller, and the air outlet located on the lower side wall of the hollow shaft is located in the gas-liquid mixing chamber.

[0015] A rotary impeller aerated bioreactor, characterized in that it comprises a tank body, a stirring device and the aeration device according to claim 8, wherein the tank body is provided with an air outlet and a material outlet, the stirring device is fixedly mounted on the tank body, the aeration device is fixedly mounted obliquely on the lower side wall of the tank body through a tank body connecting pipe arranged on the hollow shaft, the lower part of the hollow shaft and the rotary impeller are located inside the tank body; the angle between the horizontal plane of the central axis of the aeration device is θ, θ=15~90 0 , preferably 30 0 , 45 0 , 60 0 and 75 0 .

[0016] Furthermore, the angle θ between the central axis and the horizontal plane of the aeration device is 30 0 , 45 0 , 60 0 and 75 0 .

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention uses a rotating impeller gas distributor to generate microbubbles with a large specific surface area, increase the gas-liquid contact area, and greatly improve the mass transfer efficiency. At the same time, it avoids the potential risks of increased transmembrane pressure causing inlet pressure due to long operation time of dynamic membrane aeration and large shear force of multi-layer microporous shear aeration.

[0018] 2. The gas-liquid reactor in the present invention has a simple structure and low cost.

[0019] 3. The gas-liquid reactor of the present invention has wide applicability and is not limited to bioreactors. It can also be used for general gas-liquid two-phase and gas-liquid-solid three-phase system reactions.

[0020] 4. The independent power system of the rotating impeller of the device can adjust the rotating impeller speed at will, which improves the utilization rate of gas and greatly saves production costs.

[0021] 5. Due to the unique structure of the rotating impeller, micro bubbles are generated, which greatly improves the gas-liquid mass transfer efficiency and saves production costs, and reduces the harm of toxic and harmful gases to the environment and personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of the rotary impeller aerated bioreactor described in the present invention.

[0023] Figure 2 It is a schematic structural diagram of the rotary impeller aeration device with a liquid guide wheel according to the present invention.

[0024] Figure 3 This is a schematic structural diagram of the rotary impeller aeration device without a liquid guide wheel described in the present invention.

[0025] Figure 4 This is a top view of the structure of the rotating impeller described in Example 1.

[0026] Figure 5 This is a top view of the structure of the rotating impeller described in Example 2.

[0027] Figure 6 This is a top view of the structure of the rotating impeller described in Example 3.

[0028] Figure 7 This is a top view of the structure of the rotating impeller described in Example 4.

[0029] Figure 8 This is a top view of the structure of the rotating impeller described in Example 6.

[0030] Fig. 9 This is a top view of the structure of the rotating impeller described in Example 7.

[0031] Fig.10 This is a top view of the structure of the rotating impeller described in Example 8.

[0032] Fig.11 This is a top view of the structure of the rotating impeller described in Example 9.

[0033] Among them, 1-tank body, 2-heat exchange layer, 3-stirring motor, 4-stirring shaft, 5-stirring impeller, 6-motor, 7-magnetic fluid seal, 8-hollow shaft, 9-rotating impeller, 10-first plane partition, 11-second plane partition, 12-moon-shaped structural block, 13-first square bending block, 14-second square bending block, 15-first arc-shaped partition, 16-arrow-shaped structural block, 17-triangular structural block, 18-trapezoidal block, 19-V-shaped partition, 22-second arc-shaped partition, 23-tank body connecting pipe, 24-coupling frame, 25- Liquid guide wheel, 251-guide impeller, 221-semi-heart-shaped groove, 1-1-air outlet, 1-2-material outlet, 1-3-perspective mirror, 1-4-manhole, 1-5-sampling port, 1-6-instrument interface, 2-1-steam inlet or cooling water outlet, 2-2-steam condensate outlet or cooling water inlet, 8-1-hollow shaft air inlet, 8-2-hollow shaft air outlet, 9-1-bottom plate, 9-2-cover plate, 9-3-core shaft seat, 9-4-gas-liquid mixing chamber, 9-5-gas-liquid flow channel chamber, 9-6-liquid inlet, 9-7-gas-liquid outlet. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention. Example 1

[0035] like Figure 1 and Fig.11As shown, a rotary impeller aerated bioreactor comprises a tank body 1, a stirring device and an aeration device, an air outlet 1-1, a material outlet 1-2 and a manhole 1-4 are arranged on the side wall of the tank body 1, a perspective mirror 1-3 and a manhole 1-4 are arranged on the top side wall of the tank body 1, a sampling port 1-5 and an instrument interface 1-6 are arranged on the lower side wall of the tank body 1, a heat exchange layer 2 is arranged outside the side wall of the tank body 1, and a steam inlet or cooling water outlet 2-1 and a steam condensate outlet or cooling water inlet 2-2 are arranged on the outer side wall of the heat exchange layer 2; the stirring device comprises a stirring motor 3, a stirring shaft 4 and a plurality of stirring impellers 5 arranged axially at intervals along the stirring shaft 4, and the stirring motor 3 is fixed on the top of the tank body 1. Both solid and liquid reaction materials can enter from the manhole 1-4 or some solid materials can enter from the manhole 1-4. In this embodiment, the aeration device includes a motor 6, a magnetic fluid seal 7, a hollow shaft 8 and a rotating impeller 9. A hollow shaft air inlet 8-1 is provided on the upper end side wall of the hollow shaft 8. The upper end of the hollow shaft 8 is connected to the external air source through the magnetic fluid seal 7. The motor 6 is connected to the hollow shaft 8 through a coupling frame 24; the aeration device is obliquely fixed to the lower side wall of the tank body 1 through a tank body connecting pipe 23 provided on the hollow shaft 8, and the lower part of the hollow shaft 8 and the rotating impeller 9 are located inside the tank body 1.

[0036] If the angle between the horizontal planes of the central axis of the aeration device is too small, the rotation axis will be too long, which is difficult to implement. If the angle between the horizontal planes of the central axis of the aeration device is 90°, the rotation axis is the shortest, but it is difficult to install and the effect is not good. Therefore, in this embodiment, the angle between the horizontal planes of the central axis of the aeration device is θ, θ=15~90 0 In this embodiment, θ is preferably 30 0 , 45 0 , 60 0 and 75 0 .

[0037] The rotating impeller 9 adopts an external power device, and the rotation speed of the motor 6 can be from 0 to 3000 rpm, preferably 500 to 2000 rpm.

[0038] In this embodiment, the rotating impeller 9 includes a bottom plate 9-1 and a cover plate 9-2 which are spaced apart and coaxially arranged up and down, a core shaft seat 9-3 formed in the middle of the upper end surface of the cover plate 9-2, and a mounting hole extending from the upper end surface of the core shaft seat 9-3 downward along its axial direction to the lower end surface of the bottom plate 9-1; between the cover plate 9-2 and the bottom plate 9-1, they are divided into a gas-liquid mixing chamber 9-4 and a gas-liquid flow channel chamber 9-5 from the inside to the outside with their axes as the center, and the axial height of the gas-liquid mixing chamber 9-4 is greater than the axial height of the gas-liquid flow channel chamber 9-5; the lower end of the hollow shaft 8 is provided with a mounting hole connected to the rotating impeller 9, located in the The hollow shaft air outlet 8-2 on the lower side wall of the hollow shaft 8 is located in the gas-liquid mixing chamber 9-4, and a plurality of liquid inlets 9-6 are provided on the bottom plate 9-1 located within the range of the gas-liquid mixing chamber 9-4. The plurality of liquid inlets 9-6 are distributed in a circle around the axis. In the present embodiment, the liquid inlet 9-6 is in the shape of an arc-shaped long strip hole, and a gas-liquid outlet 9-7 is formed between the outer edges of the bottom plate 9-1 and the cover plate 9-2. A plurality of gas-liquid flow channels evenly distributed around the axis are formed in the gas-liquid flow channel chamber 9-5 by a plurality of partitions, and a diversion and contraction tube structure and a secondary acceleration and expansion structure are provided from the inside to the outside in each of the gas-liquid flow channels.

[0039] like Figure 4 As shown, in this embodiment, the partition includes a plurality of first plane partitions 10 and a plurality of second plane partitions 11, which are all distributed in a circle with the axis as the center and are alternately arranged at equal intervals. The length of the first plane partition 10 is greater than the length of the second plane partition 11. The first plane partition 10 penetrates the gas-liquid flow channel chamber 9-5 in the radial direction, and the outer side surface of the second plane partition 11 in the radial direction extends to the outer edge of the cover plate 9-2; two adjacent first plane partitions 10, the bottom plate 9-1 and the cover plate 9-2 form a gas-liquid flow channel, and there are spaced from the inside to the outside in the gas-liquid flow channel. The flow-dividing and shrinking tube structure and the secondary acceleration and expansion structure, the flow-dividing and shrinking tube structure is a crescent-shaped structural block 12 with the concave surface facing outward, the secondary acceleration and expansion structure is composed of two first square bending blocks 13 with the inner folding surface facing outward and two second square bending blocks 14 with the inner folding surface facing outward, the two first square bending blocks 13 and the two second square bending blocks 14 are mirror-symmetrically arranged on both sides of the second plane partition 11, the first square bending block 13 is located inside the second square bending block 14, and the outermost edge of the second square bending block 14 is arranged adjacent to the outer edge of the cover plate 9-2. In other embodiments, the flow-dividing and shrinking tube structure can also have other shapes that are the same or similar.

[0040] When the rotating impeller 9 aeration bioreactor is working, the bioreactor stirring device is started, and at the same time, the rotating impeller 9 aeration motor 6 is started, and fresh air enters from the rotating impeller 9 aeration device air inlet 8-1, then enters the magnetic fluid seal 7 and the hollow shaft 8, and then enters the rotating impeller 9. Driven by the motor 6, the rotating impeller 9 shears and mixes the reaction solution and the incoming gas inside the rotating impeller 9, and finally, under the action of the rotating centrifugal force, disperses them into the bioreactor. At this time, the gas is dispersed into tiny bubbles, and the microbubbles are evenly dispersed into the bioreactor solution under the action of the bioreactor stirring blades, and then the gas rises to the liquid surface and escapes from the liquid surface, and the waste gas leaves the reactor from the bioreactor outlet 1-1.

[0041] The above device is applied to the production of DHA products: sterile culture medium is prepared in the bioreactor, and DHA-producing bacteria are connected from the inoculation port of the reactor. Then, sterile air enters from the air inlet 8-1 of the aeration device of the rotating impeller 9, passes through the magnetic fluid seal 7 and the hollow shaft 8 to the rotating impeller 9, and the rotating impeller 9 shears and mixes the fermentation solution and sterile air to form microbubbles dispersed in the fermentation medium, providing enough dissolved oxygen for the bacteria to reproduce the bacteria and produce DHA products. Fermentation culture conditions: temperature 28 ° C, ventilation volume 1 vvm, tank pressure 0.06 Mpa, dissolved oxygen (DO) 10~20%, sugar supplement time is residual sugar control at 8~10 g / L, fermentation time 140 h. Finally, the wet weight of the bacteria is 416 g / L, the total oil content is 45 g / g, and the DHA content is 35 g / g, which are 20%, 10%, and 10% higher than the original conventional tank, respectively. Example 2

[0042] The device used in this embodiment is substantially the same as that in the first embodiment, except that another design of the rotating impeller 9 is used for aeration, namely, arrow-shaped and triangular secondary contraction and expansion shear mixing.

[0043] Specifically, Figure 5As shown, the partition includes a plurality of first arc partitions 15 uniformly distributed in a circle with the axis as the center, one end of the first arc partition 15 is located at the outer edge of the cover plate 9-2, and the other end is located on the inner ring line of the gas-liquid flow channel chamber 9-5, and two adjacent first arc partitions 15, the bottom plate 9-1 and the cover plate 9-2 form a gas-liquid flow channel, and a shunt and shrink tube structure and a secondary acceleration and expansion structure are arranged in the gas-liquid flow channel from the inside to the outside. The shunt and shrink tube structure is an arrow-shaped structural block 16 with the tip facing the inside, and the secondary acceleration and expansion structure is a triangular structural block 17 with the tip facing the arrow-shaped structural block 16, and the outer side surface of the triangular structural block 17 is located at the outer edge of the cover plate 9-2. Two shear blocks are arranged on the inner side surfaces of two adjacent first arc partitions 15 in a mirror-image manner. The shape of the shear block can be trapezoidal, triangular, hexagonal or circular. In this embodiment, the shear block is in the shape of a trapezoidal block, and two trapezoidal blocks 18 are mirror-imaged on the inner sides of two adjacent first arc-shaped partitions 15. The two trapezoidal blocks are located on the outside of the arrow-shaped structural block 16, and the tip of the triangular structural block 17 facing the arrow-shaped structural block 16 is located between the two trapezoidal blocks.

[0044] Using the above device, a sterile culture medium is prepared in a bioreactor, and the DHA-producing bacteria are connected from the inoculation port of the reactor. Then, sterile air enters from the air inlet 8-1 of the aeration device of the rotating impeller 9, passes through the magnetic fluid seal 7 and the hollow shaft 8 to the rotating impeller 9, and the rotating impeller 9 shears and mixes the fermentation solution and the sterile air to form microbubbles dispersed in the fermentation medium, providing enough dissolved oxygen for the bacteria to reproduce the bacteria and produce DHA products. Fermentation culture conditions: temperature 28 ° C, ventilation volume 1vvm, tank pressure 0.06 Mpa, dissolved oxygen (DO) 10~20%, sugar supplement time is residual sugar control at 8~10 g / L, fermentation time 140 h. Finally, the wet weight of the bacteria is 425 g / L, the total oil content is 47 g / g, and the DHA content is 36 g / g, which are 24%, 13%, and 12% higher than the original conventional tank, respectively. Example 3

[0045] The device used in this embodiment is substantially the same as that in the first embodiment, except that another design of the rotating impeller 9 is used for aeration, namely, a polygonal secondary contraction and expansion shear mixing method is used.

[0046] Specifically, Figure 6As shown, the partition includes a plurality of V-shaped partitions 19 which are evenly distributed in a circle with the axis as the center and have an inner angle greater than 90°. One end of the V-shaped partition 19 is located at the outer edge of the cover plate 9-2, and the other end is located on the inner ring line of the gas-liquid flow channel chamber 9-5; two adjacent V-shaped partitions 19, the bottom plate 9-1 and the cover plate 9-2 form a gas-liquid flow channel, and two secondary acceleration and expansion structures are arranged in sequence from the inside to the outside in the gas-liquid flow channel. The two secondary acceleration and expansion structures are two inner polygonal structural blocks 20 and an outer polygonal structural block 21 of different shapes. Both side ends of the two polygonal structural blocks along the extension direction of the gas-liquid flow channel are pointed. The inner polygonal structural block 20 and the outer polygonal structural block 21 can be polygonal structures of any shape, and polygonal structures of different shapes have different effects.

[0047] Using the above device, a sterile culture medium is prepared in a bioreactor, and the DHA-producing bacteria are connected from the inoculation port of the reactor. Then, sterile air enters from the air inlet 8-1 of the aeration device of the rotating impeller 9, passes through the magnetic fluid seal 7 and the hollow shaft 8 to the rotating impeller 9, and the rotating impeller 9 shears and mixes the fermentation solution and the sterile air to form microbubbles dispersed in the fermentation medium, providing enough dissolved oxygen for the bacteria to reproduce the bacteria and produce DHA products. Fermentation culture conditions: temperature 28 ° C, ventilation volume 1vvm, tank pressure 0.06 Mpa, dissolved oxygen (DO) 10~20%, sugar supplement time is residual sugar control at 8~10 g / L, fermentation time 140 h. Finally, the wet weight of the bacteria is 409 g / L, the total oil content is 44 g / g, and the DHA content is 33 g / g, which are 19%, 9%, and 8% higher than the original conventional tank, respectively. Example 4

[0048] The device used in this embodiment is substantially the same as that in Embodiment 1, except that another design of the rotating impeller 9 is used for aeration, namely, a shear mixing method of a microchannel flow channel is used.

[0049] Specifically, Figure 7 As shown, the partition includes a plurality of second arc-shaped partitions 22 uniformly distributed in a circle with the axis as the center, one end of the second arc-shaped partition 22 is located at the outer edge of the cover plate 9-2, and the other end is located on the inner ring line of the gas-liquid flow channel chamber 9-5; a plurality of semi-heart-shaped grooves 221 are evenly spaced along the arc direction on the side surfaces of the two sides of the second arc-shaped partition 22, and the semi-heart-shaped grooves 221 on the opposite sides of two adjacent second arc-shaped partitions 22 are arranged opposite to each other at one time, and the two adjacent second arc-shaped partitions 22, the bottom plate 9-1 and the cover plate 9-2 form a gas-liquid flow channel with a microchannel heart-shaped mixing shear structure.

[0050] Using the above device, a sterile culture medium is prepared in a bioreactor, and the DHA-producing bacteria are connected from the inoculation port of the reactor. Then, sterile air enters from the air inlet 8-1 of the aeration device of the rotating impeller 9, passes through the magnetic fluid seal 7 and the hollow shaft 8 to the rotating impeller 9, and the rotating impeller 9 shears and mixes the fermentation solution and the sterile air to form microbubbles dispersed in the fermentation medium, providing enough dissolved oxygen for the bacteria to reproduce the bacteria and produce DHA products. Fermentation culture conditions: temperature 28 ° C, ventilation volume 1vvm, tank pressure 0.06 Mpa, dissolved oxygen (DO) 10~20%, sugar supplement time is residual sugar control at 8~10 g / L, fermentation time 140 h. Finally, the wet weight of the bacteria is 418 g / L, the total oil content is 46 g / g, and the DHA content is 37 g / g, which are 22%, 13%, and 14% higher than the original conventional tank, respectively.

[0051] In order to distribute the external liquid more evenly into the various flow channels of the rotating impeller 9, so that each fluid can be better mixed and sheared with gas and liquid, in some embodiments, a liquid guide wheel is provided at the inner bottom of the gas-liquid mixing chamber 9-4, and the liquid guide wheel is penetrated and fixed at the lower end of the gas guide structure; the number of guide impellers on the liquid guide wheel is 4 or 6 or 8 or 12 or 16 or 24, preferably 6 or 8 or 12 or 16. Example 5

[0052] The device used in this embodiment is substantially the same as that in Embodiment 1, with the only difference being that another design of rotating impeller 9 is used for aeration, namely, a liquid guide wheel 25 is provided at the inner bottom of the gas-liquid mixing chamber 9-4, and the liquid guide wheel 25 is penetrated and fixed at the lower end of the gas guide structure.

[0053] Specifically, Figure 8As shown, the partition includes a plurality of first plane partitions 10 and a plurality of second plane partitions 11, which are all distributed in a circle with the axis as the center and are alternately arranged at equal intervals. The length of the first plane partition 10 is greater than the length of the second plane partition 11. The first plane partition 10 penetrates the gas-liquid flow channel chamber 9-5 in the radial direction, and the outer side surface of the second plane partition 11 in the radial direction extends to the outer edge of the cover plate 9-2; two adjacent first plane partitions 10, the bottom plate 9-1 and the cover plate 9-2 form a gas-liquid flow channel, and a flow dividing and contraction arrangement is arranged from the inside to the outside in the gas-liquid flow channel. The secondary acceleration and expansion structure is a crescent-shaped structural block 12 with the concave surface facing outward, and the secondary acceleration and expansion structure is composed of two first square bending blocks 13 with the inner folding surface facing outward and two second square bending blocks 14 with the inner folding surface facing outward. The two first square bending blocks 13 and the two second square bending blocks 14 are mirror-symmetrically arranged on both sides of the second plane partition 11, and the first square bending block 13 is located inside the second square bending block 14, and the outermost edge of the second square bending block 14 is arranged adjacent to the outer edge of the cover plate 9-2. In other embodiments, the flow-dividing and shrinking structure can also have other shapes that are the same or similar. Using the above device, a sterile culture medium is prepared in a bioreactor, and the DHA-producing bacteria are connected from the inoculation port of the reactor. Then, sterile air enters from the air inlet 8-1 of the aeration device of the rotating impeller 9, passes through the magnetic fluid seal 7 and the hollow shaft 8 to the rotating impeller 9, and the rotating impeller 9 shears and mixes the fermentation solution and the sterile air to form microbubbles dispersed in the fermentation medium, providing enough dissolved oxygen for the bacteria to reproduce the bacteria and produce DHA products. Fermentation culture conditions: temperature 28 ° C, ventilation volume 1 vvm, tank pressure 0.06 Mpa, dissolved oxygen (DO) 10~20%, sugar supplement time is residual sugar control at 8~10 g / L, fermentation time 140 h. Finally, the wet weight of the bacteria is 467 g / L, the total oil content is 46g / g, and the DHA content is 37 g / g, which are 26%, 20%, and 17% higher than the original conventional tank, respectively. Example 6

[0054] The device used in this embodiment is substantially the same as that in Embodiment 1, with the only difference being that another design of rotating impeller 9 is used for aeration, namely, a liquid guide wheel 25 is provided at the inner bottom of the gas-liquid mixing chamber 9-4, and the liquid guide wheel 25 is penetrated and fixed at the lower end of the gas guide structure.

[0055] Specifically, Fig. 9As shown, the partition includes a plurality of first arc partitions 15 uniformly distributed in a circle with the axis as the center, one end of the first arc partition 15 is located at the outer edge of the cover plate 9-2, and the other end is located on the inner ring line of the gas-liquid flow channel chamber 9-5, and two adjacent first arc partitions 15, the bottom plate 9-1 and the cover plate 9-2 form a gas-liquid flow channel, and a flow splitting and shrinking tube structure and a secondary acceleration and expansion structure are sequentially arranged in the gas-liquid flow channel from the inside to the outside, and the flow splitting and shrinking tube structure is an arrow-shaped structural block 16 with the tip facing the inside, and the secondary acceleration and expansion structure is a triangular structural block 17 with the tip facing the arrow-shaped structural block 16, and the outer side surface of the triangular structural block 17 is located at the outer edge of the cover plate 9-2. Two trapezoidal blocks 18 are arranged in a mirror-image manner on the inner side surfaces of two adjacent first arc partitions 15, and the two trapezoidal blocks are located on the outside of the arrow-shaped structural block 16, and the tip of the triangular structural block 17 facing the arrow-shaped structural block 16 is located between the two trapezoidal blocks.

[0056] Using the above device, a sterile culture medium is prepared in a bioreactor, and the DHA-producing bacteria are connected from the inoculation port of the reactor. Then, sterile air enters from the air inlet 8-1 of the aeration device of the rotating impeller 9, passes through the magnetic fluid seal 7 and the hollow shaft 8 to the rotating impeller 9, and the rotating impeller 9 shears and mixes the fermentation solution and the sterile air to form microbubbles dispersed in the fermentation medium, providing enough dissolved oxygen for the bacteria to reproduce the bacteria and produce DHA products. Fermentation culture conditions: temperature 28 ° C, ventilation volume 1vvm, tank pressure 0.06 Mpa, dissolved oxygen (DO) 10~20%, sugar supplement time is residual sugar control at 8~10 g / L, fermentation time 140 h. Finally, the wet weight of the bacteria is 489 g / L, the total oil content is 47 g / g, and the DHA content is 39 g / g, which are 31%, 24%, and 19% higher than the original conventional tank, respectively. Example 7

[0057] The device used in this embodiment is substantially the same as that in Embodiment 1, with the only difference being that another design of rotating impeller 9 is used for aeration, namely, a liquid guide wheel 25 is provided at the inner bottom of the gas-liquid mixing chamber 9-4, and the liquid guide wheel 25 is penetrated and fixed at the lower end of the gas guide structure.

[0058] Specifically, Fig.10As shown, the partition includes a plurality of V-shaped partitions 19 which are evenly distributed in a circle with the axis as the center and have an inner angle greater than 90°. One end of the V-shaped partition 19 is located at the outer edge of the cover plate 9-2, and the other end is located on the inner ring line of the gas-liquid flow channel chamber 9-5; two adjacent V-shaped partitions 19, the bottom plate 9-1 and the cover plate 9-2 form a gas-liquid flow channel, and two secondary acceleration and expansion structures are arranged in sequence from the inside to the outside in the gas-liquid flow channel. The two secondary acceleration and expansion structures are two inner polygonal structural blocks 20 and outer polygonal structural blocks 21 of different shapes, and both side ends of the two polygonal structural blocks along the extension direction of the gas-liquid flow channel are pointed.

[0059] Using the above device, a sterile culture medium is prepared in a bioreactor, and the DHA-producing bacteria are connected from the inoculation port of the reactor. Then, sterile air enters from the air inlet 8-1 of the aeration device of the rotating impeller 9, passes through the magnetic fluid seal 7 and the hollow shaft 8 to the rotating impeller 9, and the rotating impeller 9 shears and mixes the fermentation solution and the sterile air to form microbubbles dispersed in the fermentation medium, providing enough dissolved oxygen for the bacteria to reproduce the bacteria and produce DHA products. Fermentation culture conditions: temperature 28 ° C, ventilation volume 1vvm, tank pressure 0.06 Mpa, dissolved oxygen (DO) 10~20%, sugar supplement time is residual sugar control at 8~10 g / L, fermentation time 140 h. Finally, the wet weight of the bacteria is 465 g / L, the total oil content is 45 g / g, and the DHA content is 37 g / g, which are 25%, 19%, and 16% higher than the original conventional tank, respectively. Example 8

[0060] The device used in this embodiment is substantially the same as that in Embodiment 1, with the only difference being that another design of rotating impeller 9 is used for aeration, namely, a liquid guide wheel 25 is provided at the inner bottom of the gas-liquid mixing chamber 9-4, and the liquid guide wheel 25 is penetrated and fixed at the lower end of the gas guide structure.

[0061] Specifically, Fig.11 As shown, the partition includes a plurality of second arc-shaped partitions 22 uniformly distributed in a circle with the axis as the center, one end of the second arc-shaped partition 22 is located at the outer edge of the cover plate 9-2, and the other end is located on the inner ring line of the gas-liquid flow channel chamber 9-5; a plurality of semi-heart-shaped grooves 221 are evenly spaced along the arc direction on the side surfaces of the two sides of the second arc-shaped partition 22, and the semi-heart-shaped grooves 221 on the opposite sides of two adjacent second arc-shaped partitions 22 are arranged opposite to each other at one time, and the two adjacent second arc-shaped partitions 22, the bottom plate 9-1 and the cover plate 9-2 form a gas-liquid flow channel with a microchannel heart-shaped mixing shear structure.

[0062] Using the above device, a sterile culture medium is prepared in a bioreactor, and the DHA-producing bacteria are connected from the inoculation port of the reactor. Then, sterile air enters from the air inlet 8-1 of the aeration device of the rotating impeller 9, passes through the magnetic fluid seal 7 and the hollow shaft 8 to the rotating impeller 9, and the rotating impeller 9 shears and mixes the fermentation solution and the sterile air to form microbubbles dispersed in the fermentation medium, providing enough dissolved oxygen for the bacteria to reproduce the bacteria and produce DHA products. Fermentation culture conditions: temperature 28 ° C, ventilation volume 1vvm, tank pressure 0.06 Mpa, dissolved oxygen (DO) 10~20%, sugar supplement time is residual sugar control at 8~10 g / L, fermentation time 140 h. Finally, the wet weight of the bacteria is 481 g / L, the total oil content is 45 g / g, and the DHA content is 37 g / g, which are 29%, 20%, and 18% higher than the original conventional tank, respectively.

[0063] Those skilled in the art should understand that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A rotary impeller, characterized in that: It includes a bottom plate and a cover plate spaced apart and coaxially arranged up and down, and the space between the cover plate and the bottom plate is divided into a gas-liquid mixing chamber and a gas-liquid flow channel chamber from the inside to the outside with its axis as the center, and an air guide structure extends into the gas-liquid mixing chamber, and a plurality of liquid inlets are arranged on the bottom plate located within the range of the gas-liquid mixing chamber, and a gas-liquid outlet is formed between the outer edges of the bottom plate and the cover plate. A plurality of gas-liquid flow channels evenly distributed around the axis are formed in the gas-liquid flow channel chamber by a plurality of partitions, and one or more of a diversion and contraction structure, a secondary acceleration and expansion structure, and a microchannel mixing shear structure are arranged in each of the gas-liquid flow channels.

2. The rotary impeller according to claim 1, characterized in that: A liquid guide wheel is provided at the inner bottom of the gas-liquid mixing chamber, and the liquid guide wheel is penetrated and fixed at the lower end of the gas guide structure; the number of guide impellers on the liquid guide wheel is 4 or 6 or 8 or 12 or 16 or 24, preferably 6 or 8 or 12 or 16.

3. The rotary impeller according to claim 1 or 2, characterized in that: The rotating impeller also includes a core shaft seat formed in the middle of the upper end surface of the cover plate, and a mounting hole extending axially downward from the upper end surface of the core shaft seat to the lower end surface of the base plate, and the air guide structure is connected to the rotating impeller through the mounting hole; the axial height of the gas-liquid mixing chamber is greater than the axial height of the gas-liquid flow channel chamber.

4. The rotary impeller according to claim 3, characterized in that: The partition includes a plurality of first plane partitions and a plurality of second plane partitions, which are distributed in a circle with the axis as the center and alternately arranged at equal intervals. The length of the first plane partition is greater than that of the second plane partition. The first plane partition penetrates the gas-liquid flow channel chamber in the radial direction, and the outer side surface of the second plane partition in the radial direction extends to the outer edge of the cover plate; two adjacent first plane partitions, the bottom plate and the cover plate form a gas-liquid flow channel, and a diverter and shrinkage tube structure and a secondary acceleration and expansion structure are arranged from the inside to the outside in the gas-liquid flow channel. The diverter and shrinkage tube structure is a crescent-shaped structural block with the concave surface facing the outside, and the secondary acceleration and expansion structure is composed of two first square bending blocks with the inner folding surface facing the outside and two second square bending blocks with the inner folding surface facing the outside. The two first square bending blocks and the two second square bending blocks are mirror-symmetrically arranged on both sides of the second plane partition, and the first square bending block is located on the inner side of the second square bending block.

5. The rotary impeller according to claim 3, characterized in that: The partition includes a plurality of first arc-shaped partitions uniformly distributed in a circle with the axis as the center, one end of the first arc-shaped partition is located at the outer edge of the cover plate, and the other end is located on the inner ring line of the gas-liquid flow channel chamber, and two adjacent first arc-shaped partitions, the bottom plate and the cover plate form a gas-liquid flow channel, and a diversion and shrinkage structure and a secondary acceleration and expansion structure are arranged in the gas-liquid flow channel from the inside to the outside. The diversion and shrinkage structure is an arrow-shaped structural block with the tip facing the inside, and the secondary acceleration and expansion structure is a triangular structural block with the tip facing the arrow-shaped structural block, and the outer side surface of the triangular structural block is located at the outer edge of the cover plate; two shear block trapezoidal blocks are arranged in a mirror-image manner on the inner side surfaces of two adjacent first arc-shaped partitions.

6. The rotary impeller according to claim 3, characterized in that: The partition includes a plurality of V-shaped partitions which are evenly distributed in a circle with an axis as the center and have an inner angle greater than 90°. One end of the V-shaped partition is located at the outer edge of the cover plate, and the other end is located on the inner ring line of the gas-liquid flow channel chamber. Two adjacent V-shaped partitions, the bottom plate and the cover plate form a gas-liquid flow channel. Two secondary acceleration and expansion structures are arranged in sequence from the inside to the outside in the gas-liquid flow channel. The two secondary acceleration and expansion structures are two polygonal structural blocks of different shapes, and both side ends of the two polygonal structural blocks along the extension direction of the gas-liquid flow channel are pointed.

7. The rotary impeller according to claim 3, characterized in that: The partition includes a plurality of second arc-shaped partitions uniformly distributed in a circle with the axis as the center, one end of the second arc-shaped partition is located at the outer edge of the cover plate, and the other end is located on the inner ring line of the gas-liquid flow channel chamber; a plurality of semi-heart-shaped grooves are evenly spaced along the arc direction on the side surfaces of the second arc-shaped partitions, and the semi-heart-shaped grooves on the opposite sides of two adjacent second arc-shaped partitions are arranged opposite to each other, and the two adjacent second arc-shaped partitions, the bottom plate and the cover plate form a gas-liquid flow channel with a microchannel heart-shaped mixing shear structure.

8. An aeration device, characterized in that: The aeration device includes a motor, a magnetic fluid seal, a hollow shaft and a rotating impeller. An air inlet is provided on the upper end side wall of the hollow shaft. The upper end of the hollow shaft is connected to an external air source through a magnetic fluid seal. The motor is connected to the hollow shaft through a coupling frame. The rotating impeller is the rotating impeller described in claims 1 to 7. The lower end of the hollow shaft is penetrated and fixed to the rotating impeller. The air outlet located on the lower side wall of the hollow shaft is located in the gas-liquid mixing chamber.

9. A rotary impeller aerated bioreactor, characterized in that: The invention comprises a tank body, a stirring device and the aeration device as claimed in claim 8, wherein the tank body is provided with an air outlet and a material outlet, the stirring device is fixed on the tank body, the aeration device is fixedly arranged on the lower side wall of the tank body by a tank body connecting pipe arranged on the hollow shaft, the lower part of the hollow shaft and the rotating impeller are located inside the tank body; the angle between the central axis of the aeration device and the horizontal plane is θ, θ=15~90 0 , preferably 30 0 , 45 0 , 60 0 and 75 0 .

10. The rotary impeller aerated bioreactor according to claim 9, characterized in that: The angle θ between the central axis and the horizontal plane of the aeration device is 30 0 , 45 0 , 60 0 and 75 0 .

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