Semi-solid state fermentation bioreactor

Abstract

The utility model relates to the technical field of bioreactors, and discloses a semi-solid fermentation bioreactor, which comprises a tank body with a feed port and a discharge port, a rotary guide cylinder is arranged in the tank body, the rotary guide cylinder can rotate around the axis of the rotary guide cylinder, and the feed port is communicated with the discharge port. The inner wall and / or the outer wall of the rotary guide cylinder are / is provided with a spiral band extending along the length direction of the rotary guide cylinder, the rotary guide cylinder is arranged in the tank body, and the inner wall and / or the outer wall of the rotary guide cylinder are / is provided with the spiral band extending along the length direction of the rotary guide cylinder. The spiral belt can forcibly drive reaction materials in the tank body to ascend or descend when the rotary guide cylinder rotates around the axis of the rotary guide cylinder, so that the reaction materials in the tank body are fully mixed, and the purpose of strengthening mass transfer and heat transfer of semi-solid fermentation materials is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of bioreactors, and particularly relates to a semi-solid fermentation bioreactor. Background Art

[0002] In related technologies, solid-state fermentation generally refers to a fermentation method in which microorganisms carry out fermentation on a solid culture medium without or with almost no free-flowing free water. The solid culture medium can be a natural solid culture medium or an impregnated inert carrier. In solid-state fermentation, the gas phase is the continuous phase and the mobile phase, and the oxygen required by microorganisms mainly comes from the gas phase.

[0003] The natural solid culture medium used in solid-state fermentation usually uses inexpensive, rich in sources and types, and complex in composition insoluble solid biomass (such as grains, beans, lignocellulose, etc.) as the main raw material, and is mixed with auxiliary fermentation raw materials such as inorganic salts and growth factors. The main raw material in the form of particles serves as a nutritional carrier, providing both the substrate and energy required for the growth and metabolism of microorganisms, and also playing a supporting role as a particulate carrier to provide a microenvironment for the growth of microorganisms.

[0004] Compared with liquid fermentation, those skilled in the art generally believe that solid-state fermentation has advantages such as relatively simple equipment and process, energy conservation, water conservation, and less discharge of polluting wastewater. However, the cycle of solid-state fermentation is relatively long, and the conversion and utilization rate of insoluble solid biomass is relatively low. The specific reasons include: 1) The core of microbial fermentation is enzyme-catalyzed reactions, and water is the reaction medium for the vast majority of biological enzymes. In the absence of free water, the catalytic environment of extracellular biological enzymes is poor, and their catalytic ability cannot be fully exerted; 2) The average particle size of the nutrient carriers in forced-aeration solid-state fermentation is generally relatively large. The large steric hindrance and its non-productive adhesion to microorganisms and enzymes severely restrict the accessibility of microorganisms and enzymes to the substrate; 3) The particle size of the solid culture medium must be appropriate to facilitate sufficient contact between the substrate and microorganisms and to play a loose supporting role, maintaining the air permeability of the discontinuous physical structure of the solid culture medium and ensuring gas diffusion. If the particle size of the solid culture medium is too small and the particle gaps are narrow, sufficient oxygen cannot be provided for the microorganisms. Therefore, the nutrient carriers cannot be consumed excessively, which directly limits the conversion and utilization rate of the main raw materials; 4) Due to the difficulties in mass transfer and heat transfer in solid-state fermentation, the material not only has macroscopic inhomogeneity, but the heterogeneity of the microenvironment of the substrate particles also seriously affects fermentation, manifested as gradients of oxygen, water, carbon source, nitrogen source, product, pH, microorganisms, and enzymes, etc., and the significant differences in the microenvironments of the surface and bottom layers of the microbial film formed by colonization on the surface of the substrate particles, resulting in significant differences in microbial metabolic growth and enzymatic reactions; 5) Soluble nutrient components penetrate into the interior of the solid substrate particles and are not easily utilized, resulting in low utilization rates and high residues of these components; 6) Filamentous fungi often produce a large number of spores in the solid-state fermentation environment. The production of spores consumes a large amount of nutrients. If the goal is not to obtain spores, the production of spores reduces the effective conversion rate of the substrate and the yield of the target product. In summary, the proportion of the target product in solid-state fermentation products is not high, and it is usually only applicable to processes with relatively low requirements for product purity. Moreover, the downstream product separation process is also a difficult process.

[0005] In terms of large-scale solid-state fermentation equipment and its process control, due to the lack of large reactors that can meet the requirements of strictly controllable culture conditions, the mechanization level of solid-state fermentation is low and the labor intensity is high, resulting in weak competitiveness in the large-scale production efficiency of many products and unstable control of product quality. For pure culture fermentation and mixed culture fermentation products with defined strains, contamination will cause heavy losses of products, funds, and time. Therefore, aseptic operation of the fermentation process must be carried out in a large closed space. It is precisely the rigid requirement for aseptic operation in a closed space that makes it difficult to achieve large-scale controllable solid-state fermentation processes. The volume of existing closed dynamic solid-state fermentation reactors is difficult to exceed 20m 3, which are mainly reflected in: difficult mass and heat transfer, obvious gradients in nutrition, products and temperature, difficulties in monitoring and controlling parameters such as pH, temperature, humidity, oxygen content, biomass, substrate and product concentration during the fermentation process, and low levels of automation and controllability. It is very difficult to carry out feeding and discharging operations on solid materials while ensuring aseptic operation, so it is also difficult to achieve continuous fermentation. The apparent utilization rate of the effective volume of shallow pan type, thick layer ventilation tank type and drum type solid state fermentation reactors is generally less than 40%. Due to the need to leave gaps between substrates, the actual utilization rate of the reactor is even lower. For example, it is very difficult to control the temperature and other parameters during the fermentation process of traditional solid state rice wine, vinegar, sauce, etc. Therefore, only small containers can be used, with low efficiency, low raw material utilization rate, long fermentation cycle and high cost, which do not meet the requirements of large-scale industrialization.

[0006] To sum up, an important factor restricting the application of solid state fermentation in modern bioreaction engineering is the lack of mature and applicable large reactors, which has become a worldwide problem [Chen Hongzhang et al. Bioprocess Engineering and Equipment [M]. Beijing: Chemical Industry Press, 2004: 107.].

[0007] In addition, if the fermented material needs to be leached with water or biological reactions such as enzymatic hydrolysis are carried out, a large amount of free water must be added, and the product will be diluted by water after adding water. If the water leaching or enzymatic reaction process requires maintaining a sterile environment and stirring, existing solid state fermentation reactors are often not applicable. In addition, for some raw materials with high moisture content and small particle size (such as wine lees, bean dregs, potato dregs, beet dregs, coffee dregs, sauce dregs, peels and residues of fruits and vegetables, grass, banana pseudostems, cacti, kitchen waste, etc.), in order to meet the requirements of the moisture content of the solid culture medium, dehydration treatment needs to be carried out, or a large amount of dry matrix needs to be added, resulting in increased raw material, process costs and energy consumption, and a significant reduction in the use ratio of the target raw material.

[0008] In the process of researching and developing the fermentation and utilization of lignocellulose and food industry residues, it is crucial to provide a closed semi-solid state fermentation bioreactor to improve the conversion and utilization rate of raw materials to ensure the predictability and stability of the quality of fermentation products.

[0009] On the other hand, from the perspective of fermentation or enzymatic reaction products, if the product is an insoluble substance such as starch, when the product concentration is high, the reaction material is in a semi-solid state, and it is very difficult for existing liquid deep fermentation reactors or general stirred enzymatic reaction reactors to achieve suspension and mixing of the material, and the structure of the reactor also needs to be innovated. Summary of the Utility Model

[0010] The purpose of the present utility model is to solve the problem that traditional reactors cannot be applied to semi-solid fermentation reactions, and to provide a closed semi-solid fermentation bioreactor suitable for pure bacteria fermentation or defined-strain mixed bacteria fermentation. This semi-solid fermentation bioreactor can effectively improve the mass transfer and heat transfer effects of the fermentation materials and ensure the effective progress of the aseptic operation of semi-solid fermentation reactions.

[0011] To achieve the above object, the present utility model provides a semi-solid fermentation bioreactor, including a tank body having a feed inlet and a discharge outlet. A rotary deflector is arranged inside the tank body, and the rotary deflector is arranged to be rotatable around its own axis. A spiral band extending along its length direction is arranged on the inner wall and / or outer wall of the rotary deflector.

[0012] Preferably, there is one rotary deflector and it is coaxially arranged with the tank body.

[0013] Preferably, there are multiple rotary deflectors, and the multiple rotary deflectors are evenly spaced and distributed inside the tank body.

[0014] Preferably, spiral bands are simultaneously arranged on the inner wall and outer wall of the rotary deflector, and the spiral band on the inner wall of the rotary deflector and the spiral band on the outer wall of the rotary deflector have opposite helix directions.

[0015] Preferably, at least part of the barrel wall of the rotary deflector is arranged as a hollow structure.

[0016] Preferably, a motor is arranged at the inner top of the tank body, and the motor is used to drive the rotary deflector to rotate around its own axis.

[0017] Preferably, an antifoaming paddle is arranged above the rotary deflector, and the antifoaming paddle is driven by the motor to rotate around the axis of the rotary deflector.

[0018] Preferably, the semi-solid fermentation bioreactor further includes a spiral ribbon propeller, and the spiral ribbon propeller is coaxially inserted into the rotary deflector and is driven to rotate around its own axis to push the materials inside the rotary deflector to flow.

[0019] Preferably, a fixed deflector is arranged between the lower end of the rotary deflector and the inner bottom of the tank body. The fixed deflector is coaxially arranged with the rotary deflector. A rim propeller is arranged on the inner barrel wall and / or outer barrel wall of the fixed deflector, and the rim propeller is used to push the materials to move axially along the fixed deflector; and / or

[0020] The semi-solid state fermentation bioreactor further includes an airbag and a pipeline. The airbag is arranged below the liquid level in the tank body, and the pipeline is configured to be able to input fluid into the airbag to control the volume of the airbag.

[0021] Preferably, the fixed draft tube is an integral cylinder or composed of at least two segmented cylinders combined along the axial direction of the tank body, and an annular gap is provided between the axial directions of two adjacent segmented cylinders.

[0022] Through the above technical solution, by arranging a rotary draft tube in the tank body, and a spiral band extending along its length direction is arranged on the inner wall and / or outer wall of the rotary draft tube. Compared with the stirring paddle structure in the traditional reactor, the spiral band in the present invention can forcibly drive the reaction materials in the tank body to rise or fall when the rotary draft tube rotates around its own axis, promoting the full mixing of the reaction materials in the tank body, so as to achieve the purpose of strengthening the mass transfer and heat transfer of the semi-solid state fermentation materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of a semi-solid state fermentation bioreactor provided by the present invention;

[0024] Figure 2 is a top view of a semi-solid state fermentation bioreactor provided by the present invention with multiple rotary draft tubes;

[0025] Figure 3 is a schematic structural diagram of another semi-solid state fermentation bioreactor provided by the present invention;

[0026] Figure 4 is a schematic structural diagram of still another semi-solid state fermentation bioreactor provided by the present invention;

[0027] Figure 5 is a schematic structural diagram of a semi-solid state fermentation bioreactor provided by the present invention with both a rotary draft tube and a fixed draft tube;

[0028] Figure 6 is a schematic structural diagram of a structure for supplying gas by designing the rim propeller as a self-priming impeller provided by the present invention;

[0029] Figure 7 is a schematic structural diagram of a semi-solid state fermentation bioreactor with a large diameter-height ratio provided by the present invention;

[0030] Figure 8 is a schematic structural diagram of an open semi-solid state fermentation bioreactor provided by the present invention;

[0031] Figure 9It is a schematic longitudinal sectional view of a fixed draft tube with heat exchange function provided by the present utility model;

[0032] Figure 10 It is a schematic cross-sectional view of a fixed draft tube with heat exchange function provided by the present utility model.

[0033] Description of reference numerals

[0034] 100, tank body; 101, feed inlet; 102, exhaust port; 103, discharge port; 104, horizontal fixed beam frame; 105, fixed column; 106, shaft seat; 110, motor; 120, upper gas distributor; 130, lower gas distributor; 140, flow guide cone; 150, spoiler; 160, eddy current flow guide plate; 170, perforated sieve plate; 200, rotary draft tube; 210, spiral band; 220, defoaming paddle; 300, spiral ribbon propeller; 400, fixed draft tube; 401, segmented cylinder; 402, annular gap; 410, rim propeller; 411, self-priming impeller; 412, rim propeller fixed tube; 413, suction hole; 414, intake pipe; 420, draft tube heat exchange tube; 500, airbag; 510, pipeline. Detailed implementation manners

[0035] The following will describe in detail the specific implementation manners of the present utility model with reference to the accompanying drawings. It should be understood that the specific implementation manners described herein are only used to illustrate and explain the present utility model, and are not used to limit the present utility model.

[0036] As Figure 1 shown, the present utility model provides a semi-solid fermentation bioreactor, which includes a tank body 100 having a feed inlet 101 and a discharge port 103. A rotary draft tube 200 is arranged inside the tank body 100. The rotary draft tube 200 is arranged to be able to rotate around its own axis. A spiral band 210 extending along its length direction is arranged on the inner wall and / or outer wall of the rotary draft tube 200.

[0037] When using the semi-solid fermentation bioreactor provided by the present utility model for fermentation reaction, reaction materials are put into the tank body 100 through the feed inlet 101, and the materials after the fermentation reaction are discharged through the discharge port 103. In the technical solution provided by the present utility model, by arranging a rotary draft tube 200 inside the tank body 100, and a spiral band 210 extending along its length direction is arranged on the inner wall and / or outer wall of the rotary draft tube 200. Compared with the stirring paddle structure in the traditional reactor, the spiral band 210 in the present utility model can forcibly drive the semi-solid reaction materials in the tank body 100 to rise or fall when the rotary draft tube 200 rotates around its own axis, so as to promote the full mixing of the reaction materials in the tank body 100, thereby achieving the purpose of strengthening the mass transfer and heat transfer of the semi-solid fermentation materials.

[0038] Furthermore, thanks to the semi-solid fermentation bioreactor provided by the present utility model, the raw materials for fermentation production, such as insoluble solid biomass, can be first refined into sufficiently small particles and fibers, and then the space between the insoluble solid biomass particles is filled with free water to obtain a culture medium with a high solid content. This culture medium is in a slurry-like fluid state, with fine insoluble solid biomass particles, fibers, and microorganisms suspended in water. The oxygen required by the microorganisms is mainly the dissolved oxygen in the water (it should be particularly emphasized that in existing liquid submerged fermentation, the dissolved oxygen is also obtained from water, but the nutrients in its culture medium are generally soluble in water. For example, widely used starch needs to be liquefied by amylase and then dissolved in water). When the above-mentioned culture medium is put into the semi-solid fermentation bioreactor of the present utility model, the free water content of the fermentation material is high, providing an abundant reaction medium for enzymatic catalysis. The soluble substances are dissolved in water and evenly distributed; due to the significant reduction in the particle size of the insoluble substrate, the steric hindrance is reduced, and its surface area increases significantly. As the fermentation progresses, the insoluble substrate is also utilized, and the particle size of the insoluble substrate further decreases, which is more conducive to the utilization of the insoluble substrate, improving the conversion and utilization rate of the raw materials and reducing their residues; in addition, the semi-solid fermentation bioreactor provided by the present utility model is also conducive to the separation of the target product; it is suitable for using fermentation substrates with a high water content and small particle size; filamentous fungi do not produce spores in a semi-solid fermentation environment; it is suitable for the cultivation of more types of microorganisms, providing more choices for constructing a fermentation flora for mixed fermentation of defined strains, and realizing the resource-based and high-value conversion and utilization of waste streams. Therefore, using the semi-solid fermentation bioreactor provided by the present utility model for semi-solid fermentation overcomes many defects of liquid fermentation and solid fermentation at the same time.

[0039] In addition, since the reaction material applicable to the semi-solid fermentation bioreactor in the present utility model is a fluid, it is convenient to implement large-scale closed positive-pressure fermentation. Aseptic operations such as sterilization and inoculation are easy to implement and are not easily contaminated with bacteria; compared with solid materials, fluid materials are more easily mixed by gas flow and mechanical agitation to enhance mass transfer and heat transfer, making mass transfer and heat transfer no longer difficult; the adhesion of substrate particles to microorganisms and enzymes is significantly weakened, and microorganisms and enzymes are evenly distributed in the material, greatly reducing the macroscopic and microscopic heterogeneity of the material; water has a large heat capacity, and it is easy to control the temperature of the fermentation system through the heat exchange components of the reactor; there are mature sensors for parameters such as fermentation temperature, pH, dissolved oxygen, tank pressure, stirring speed, and ventilation volume, making it easy to implement monitoring and regulation, and it is also convenient for feeding, discharging, and sampling, thereby realizing continuous fermentation; off-line detection of biomass, substrate concentration, and product concentration can be conveniently carried out through aseptic sampling; the degree of automation and controllability is high, the labor productivity is high, and the quality of the fermentation product can be better stabilized; the equipment utilization rate is high, and the effective utilization rate of the tank volume can exceed 75%.

[0040] It should be noted that for the fermentation utilization and conversion of insoluble solid organic biomass, filamentous fungi and macrofungi are preferred strains. When using these mycelia for fermentation production, the influence of the shear force of stirring during the fermentation process on the mycelia must be considered, that is, on the premise of meeting the requirements of mass transfer, heat transfer and aeration in the mixing and stirring process, the shear force of stirring should be greatly reduced. Existing solid-state fermentation reactors and common liquid deep fermentation reactors such as stirring type, air-lift type, bubble column type, self-aspirating type, etc. are not applicable because they cannot achieve complete mixing of the materials in the reactor; or the shear force is too large and the stirring energy consumption is extremely high. The semi-solid fermentation bioreactor provided by the present utility model can achieve low-shear-force fermentation production and is suitable for the fermentation utilization and efficient conversion of insoluble solid organic biomass by filamentous fungi and macrofungi.

[0041] It can be understood that, as shown in Figure 1 In the semi-solid fermentation bioreactor provided by the present utility model, the feed inlet 101 can also be used as a manhole; in order to facilitate exhaust, an exhaust port 102 is further provided at the top of the tank body 100.

[0042] It should be noted that in the present utility model, the setting of the rotary draft tube 200 needs to be adaptively selected according to its own specification size and the specification size of the tank body 100 to be able to effectively push the reaction materials in the tank body 100 and ensure the enhancement of mass transfer and heat transfer. In some embodiments, one rotary draft tube 200 is provided and is coaxially arranged with the tank body 100.

[0043] In some embodiments, a plurality of rotary draft tubes 200 are provided, and the plurality of rotary draft tubes 200 are evenly spaced in the tank body 100. As shown in Figure 2 In a specific embodiment of the present utility model, four rotary draft tubes 200 are provided, and the four rotary draft tubes 200 are evenly spaced around the axis of the tank body 100.

[0044] In some embodiments, the spiral bands 210 are simultaneously provided on the inner wall and the outer wall of the rotary draft tube 200, and the spiral bands 210 on the inner wall of the rotary draft tube 200 and the spiral bands 210 on the outer wall of the rotary draft tube 200 have opposite helix directions. In this way, the reaction materials inside and outside the rotary draft tube 200 can achieve cyclic flow, which is conducive to mass transfer and heat transfer during this process and promotes the efficient progress of the fermentation reaction.

[0045] In the present utility model, in order to reduce the influence of the self-weight of the rotary draft tube 200 on its rotation and energy consumption, at least part of the tube wall of the rotary draft tube 200 is provided with a hollow structure. Combining the buoyancy it receives in the reaction material can balance the self-weight of the rotary draft tube 200, ensuring its stable and reliable rotation in the tank body 100 and effectively reducing the energy consumption required to drive the rotation of the rotary draft tube 200.

[0046] In the present utility model, the rotary draft tube 200 can be driven in any suitable driving form to rotate around its own axis in the tank body 100. In some embodiments, a motor 110 is provided at the inner top of the tank body 100, and the motor 110 is used to drive the rotary draft tube 200 to rotate around its own axis.

[0047] It can be understood that for pure bacteria fermentation and mixed bacteria fermentation products with defined bacteria species, the scheme of arranging the motor 110 outside the tank body 100 requires the use of a relatively expensive dynamic seal, and there is also a risk of external microbial contamination of the fermentation environment in the tank body 100 due to poor sealing. In the present utility model, by arranging the motor 110 at the inner top of the tank body 100, a closed fermentation environment without dynamic seal is formed, thereby ensuring the stable and reliable fermentation production at a relatively low construction cost.

[0048] In the present utility model, the motor 110 is a tubular motor with an axial flux structure. The rotor of the tubular motor with an axial flux structure can be sleeved outside the stator or inside the stator; in the tank body 100, the stator of the tubular motor can be fixed at the inner top of the tank body 100, or fixed on a vertical rod or vertical pipe extending downward from the inner top of the tank body 100. Specifically, for example Figure 1 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 7 as shown in, a fixed column 105 extending downward is provided at the inner top of the tank body 100, and the motor 110 is fixed on the fixed column 105.

[0049] Alternatively, the motor 110 is a disk-shaped motor with a radial flux structure. The rotor and stator of the disk-shaped motor with a radial flux structure are arranged at intervals up and down. There can be one or more stators, and there can also be one or more rotors.

[0050] Alternatively, the motor 110 can rotate forward and backward. By adjusting the forward and reverse rotation of the motor, the material can be pushed downward or upward in the tank body 100; further, the motor 110 is a magnetic levitation motor.

[0051] It is understandable that in the present utility model, when multiple rotary guide cylinders 200 are provided, the motors 110 corresponding to each rotary guide cylinder 200 can be independently controlled, so as to respectively regulate the pushing ability and pushing direction of each rotary guide cylinder 200 on the reaction materials in the tank body 100.

[0052] In the present utility model, in combination with Figure 1 As shown, a defoaming paddle 220 is provided above the rotary guide cylinder 200, and the defoaming paddle 220 is driven by the motor 110 to rotate around the axis of the rotary guide cylinder 200. That is to say, the motor 110 drives the defoaming paddle 220 to rotate while driving the rotary guide cylinder 200 to rotate, playing a role in defoaming.

[0053] In the present utility model, in order to further improve the flow effect of the reaction materials in the tank body 100 and strengthen mass transfer and heat transfer, the semi-solid fermentation bioreactor further includes a spiral ribbon propeller 300, and the spiral ribbon propeller 300 is coaxially inserted into the rotary guide cylinder 200 and is driven to rotate around its own axis for pushing the materials in the rotary guide cylinder 200 to flow.

[0054] In a specific embodiment of the present utility model, the spiral ribbon propeller 300 and the rotary guide cylinder 200 share a motor 110, that is, the motor 110 drives the spiral ribbon propeller 300 and the rotary guide cylinder 200 to rotate simultaneously.

[0055] In the present utility model, the spiral ribbon propeller 300 can adopt any appropriate structural form as long as it can push the materials in the rotary guide cylinder 200 to flow when rotating around its own axis. The spiral ribbon propeller 300 can be, for example, a single spiral ribbon propeller (as shown in Figure 1 ), or a double spiral ribbon propeller (as shown in Figure 8 ). Further, in order to ensure the stable and reliable rotation of the spiral ribbon propeller 300, a shaft seat 106 is provided at the inner bottom of the tank body 100 to form a rotational fit with the bottom end of the spiral ribbon propeller 300.

[0056] In some embodiments, in combination with Figure 5 As shown, a fixed guide cylinder 400 is provided between the lower end of the rotary guide cylinder 200 and the inner bottom of the tank body 100. The fixed guide cylinder 400 is coaxially arranged with the rotary guide cylinder 200, and a rim propeller 410 is provided on the inner cylinder wall and / or outer cylinder wall of the fixed guide cylinder 400, and the rim propeller 410 is used to push the materials to move axially along the fixed guide cylinder 400.

[0057] In the present utility model, the rim thruster 410 is also known as a Rim Driven Thruster (RDT), a shaftless thruster, or an integrated motor thruster. It integrates the rotor and the propeller blade of the thruster into one body without using a shaft to transmit torque. The torque generated by the motor is directly transmitted to the rim part of the rim blade through the rotor, driving the rim blade to rotate, and completely eliminating the stirring shaft system and shaft seal system passing through the tank body in the traditional stirrer. The rim thruster 410 is divided into an inner rotor rim thruster and an outer rotor rim thruster according to the position of the rotor inside and outside the stator. Compared with the traditional shaft stirring system, since it does not require shaft system equipment, it is much lighter in weight, the noise source is reduced, and the vibration is very low. It also has the advantages of high efficiency, compact structure, small volume, and a larger speed range. In addition, magnetic levitation technology can be adopted for the stator and rotor of the rim thruster 410.

[0058] In the present utility model, as a specific arrangement mode of the rim thruster 410 on the fixed draft tube 400, the cylindrical stator of the rim thruster 410 is connected to the fixed draft tube 400.

[0059] In the rim thruster 410 of the present utility model, the integrated rotor and propeller blade are called an "impeller", and the impeller can have various design forms. The propeller blade of the rim thruster 410 is preferably an inclined blade or approximately a helical surface blade, and there are two or more, symmetrically distributed. When the rim thruster 410 operates, the propeller blade presses the fluid in the corresponding area downward or upward, strengthening the flow rate of the material in the downcomer area or the upcomer area, accelerating the circulation and mixing of the reaction liquid, and breaking the aggregated bubbles in the material.

[0060] In the present utility model, the rim thruster 410 can specifically be an electric rim thruster driven by electricity or a pneumatic rim thruster driven by compressed gas. While the pneumatic rim thruster drives the rotor to rotate with compressed gas, gas is introduced into the fermentation material. Therefore, the compressed gas drive can not only make full use of the kinetic energy of the compressed gas but also introduce fresh gas into the material. The cables of the electric rim thruster and the compressed gas pipelines of the pneumatic rim thruster are easy to arrange and seal in the reactor, occupying less space.

[0061] In comparison, the rim thruster 410 on the fixed draft tube 400 provides the moving power for the reaction material in the tank body 100 from a local position, and the spiral band 210 on the rotary draft tube 200 provides the moving power for the reaction material in the tank body 100 from a larger range. By combining the rotary draft tube 200 and the fixed draft tube 400 arranged in the tank body 100, the mass transfer and heat transfer efficiency of the reaction material are effectively improved.

[0062] In addition, based on the rim propeller 410 provided by the present utility model, the utilization rate of the raw material gas can also be improved thereby. Specifically, the interior of the impeller is designed as a cavity to form a self-priming impeller 411. As Figure 6 shown, the interior cavity of the impeller communicates with the lower end of the rim propeller fixed pipe 412, and an air suction hole 413 is opened at the upper end of the rim propeller fixed pipe 412 in the tank. By increasing the rotational speed of the impeller, the gas in the top space of the reactor can be sucked into the reaction liquid from the air suction hole 413, realizing the recirculation of the gas in the top space of the reactor, so that the reaction gas can be fully utilized, reducing the emission of waste gas and the cost of treating the tail gas. The mechanism is as follows: The rim propeller 410 is directly hoisted into the tank body 100 and immersed in the material. When the impeller rotates, a liquid flow is formed around the impeller, continuously repelling the surrounding reaction materials. When the impeller rotates at a high speed and reaches the critical speed, the pressure of the materials around the impeller is lower than the pressure at the center of the impeller cavity. The impeller with a cavity generates a pressure difference at the end opening. When the local pressure drop overcomes the liquid level head of the materials, the gas in the hollow rim propeller fixed pipe 412 reaches the end opening of the rotor and is ejected at a high speed, and the air suction hole 413 at the upper end of the rim propeller fixed pipe 412 sucks the gas in the top space of the reactor, realizing the recirculation of the gas. The self-priming impeller 411 can have various design methods / structures, which are not limited in the present utility model. If the rim propeller fixed pipe 412 communicates with the intake pipe 414 outside the tank, as Figure 6 shown, the gas inside and outside the tank can be sucked in simultaneously.

[0063] In the present utility model, the fixed guide cylinder 400 is an integral cylinder or is composed of at least two segmented cylinders 401 combined along the axial direction of the tank body 100. As Figure 5 shown, in a specific embodiment of the present utility model, the fixed guide cylinder 400 is composed of two segmented cylinders 401 combined along the axial direction of the tank body 100, and an annular gap 402 is provided between the axial directions of two adjacent segmented cylinders 401.

[0064] Correspondingly, the fixed guide cylinder 400 can be a regular cylinder or a spiral cylinder, guiding the reaction materials to rise or fall in a spiral manner through it, increasing the tangential flow and turbulence of the flow field, and prolonging the residence time and flow path of the bubbles in the reaction materials, so as to achieve the purpose of promoting the reaction effect.

[0065] In some embodiments, the semi-solid fermentation bioreactor further includes a gas distributor, and the gas distributor is used to supply gas to the reaction materials in the tank body 100; fresh gas is provided to the tank body 100 through the gas distributor to meet the requirements for microbial fermentation production.

[0066] In some embodiments, the gas distributor includes an upper gas distributor 120 and / or a lower gas distributor 130. The upper gas distributor 120 is disposed at the upper inner part of the tank body 100, and the lower gas distributor 130 is disposed at the bottom inner part of the tank body 100.

[0067] It can be understood that the ventilation volumes of the upper gas distributor 120 and the lower gas distributor 130 can be controlled independently. In actual use, both the upper gas distributor 120 and the lower gas distributor 130 can be used simultaneously, or the upper gas distributor 120 or the lower gas distributor 130 can be used alone. For example Figure 1 , Figure 3 , Figure 4 and Figure 5 As shown, in a specific embodiment of the present utility model, both the upper gas distributor 120 and the lower gas distributor 130 are provided in the semi-solid fermentation bioreactor and selectively used according to specific reaction requirements.

[0068] The present utility model does not make special limitations on the structural form of the gas distributor. For example, it can be a single-tube type, an umbrella cover type, a small-hole coil type, a jet type, a swirl type or a turbine type. A microfiltration membrane can be provided at the gas outlet of the gas distributor, preferably a ceramic membrane or a sintered metal membrane, and its advantage is that the bubbles introduced into the tank body 100 can be made smaller.

[0069] In addition, the gas distributor composed of the microfiltration membrane can also press out or extract the filtrate from the tank body 100 in the reverse direction. Utilizing the pressure difference between the inside of the tank body 100 and the ventilation pipe, the materials in the tank body 100 can achieve solid-liquid separation through the microfiltration membrane, and the filtrate flows out from the ventilation pipe. This operation is applicable to the online separation of products that can pass through the microfiltration membrane produced by microbial fermentation and enzyme catalysis. By timely removing the products to reduce the feedback inhibition of the products, the coupling of fermentation and product separation, continuous fermentation and online sampling are implemented.

[0070] In the present utility model, the lower gas distributor 130 is preferably a cyclone propulsion type gas distributor. The advantage of this cyclone propulsion type gas distributor is that it can make full use of the jet kinetic energy of the compressed gas to increase the flow velocity of the rising materials. Specifically, the cyclone propulsion type gas distributor has a cavity turbine (cyclone propulsion type gas distributor turbine) rotating around the gas outlet at the air outlet of the lower ventilation pipe. The rotating vanes evenly distributed in the cavity turbine are radially open, and the upper part of the cavity turbine is connected with a paddle (cyclone propulsion type gas distributor paddle) for pushing the fluid to rise axially. When the lower gas distributor 130 injects gas into the tank body 100, the gas is guided by the rotating vanes in the cavity turbine, and the gas pushes the cavity turbine to rotate in the reverse direction. The paddle on the cavity turbine rotates accordingly, thereby pushing the fluid to move upward, strengthening the flow velocity of the fluid in the liquid-lifting area, and further breaking the bubbles at the same time.

[0071] The turbine of the cyclone-driven gas distributor can also be composed of multiple tangential-flow gas nozzles (cyclone-driven gas distributor nozzles).

[0072] The stator and rotor of the cyclone-driven gas distributor can adopt magnetic levitation technology to reduce the friction between the rotating disk and the ventilation pipe, reduce energy consumption, and extend the service life.

[0073] It should be noted that the dissolved oxygen concentration (DO) in the aerobic fermentation reaction material is an important operating variable during the reaction process, and its regulation level directly affects the changes of multiple other variable parameters. Specifically, the present utility model can regulate the DO, gas content, apparent liquid velocity, material circulation time, and mixing intensity in the reaction material through the ventilation volume of the upper gas distributor 120, the ventilation volume of the lower gas distributor 130, and the rotation speed of the rotary draft tube 200, providing the possibility for implementing new control methods for the flow field environment, temperature field, concentration field, etc.

[0074] In some embodiments, a heat exchange structure is provided on the outer wall of the tank body 100 for controlling the temperature inside the tank body 100. Exemplarily, the heat exchange structure is a heat exchange jacket or a semi-circular heat exchange tube provided on the outer wall of the tank body 100.

[0075] It should be noted that the fixed draft tube 400 itself can also be set as a hollow draft tube heat exchange tube 420 inside. The draft tube heat exchange tube 420 can be a coil tube on the inner wall and / or outer wall of the fixed draft tube 400 ( Figure 9 A is a semi-circular tube on the inner wall of the fixed draft tube 400), or a longitudinal riser tube ( Figure 10 A is a circular vertical tube on the inner wall of the fixed draft tube 400, Figure 10 B is a square vertical tube on the inner wall of the fixed draft tube 400, Figure 10 C is a semi-circular riser tube on the outer wall of the fixed draft tube 400); it can also directly use the draft tube heat exchange tube 420 to longitudinally and / or transversely piece together the shape of the fixed draft tube 400 ( Figure 9 B is the shape of the fixed draft tube 400 pieced together by horizontally spiraling square tubes, Figure 10 D is the shape of the fixed draft tube 400 pieced together by longitudinally connecting square tubes).

[0076] A heat exchange fluid is introduced into the hollow jacket of the fixed draft tube 400 or the inside of the draft tube heat exchange tube 420, enabling the fixed draft tube 400 to have the function of a heat exchanger, heating and cooling the reaction material, improving the temperature control performance of the semi-solid fermentation reactor, heating up and cooling down faster, not only saving the heating and cooling time for sterilization, improving the equipment utilization rate, but also being able to adapt to fermentations with large heat release.

[0077] In some embodiments, a guide cone 140 is provided at the inner bottom of the tank body 100; the guide cone 140 is provided to guide the reaction materials at the inner bottom of the tank body 100, thereby improving the circulation and mixing effects of the reaction materials at this position, avoiding the formation of a flow dead zone in the center of the inner bottom of the tank body 100, and especially preventing the accumulation of fermentation particles at this position.

[0078] In some embodiments, in combination Figure 3 and Figure 4 As shown, a spoiler 150 is provided on the inner upper part of the tank body 100, one end of the spoiler 150 is fixed on the inner wall of the tank body 100, and the other end is inclined toward the center of the tank body 100. By providing the spoiler 150, the reaction materials are disturbed to promote more efficient mixing of the reaction materials.

[0079] In some embodiments, in combination Figure 3 As shown, a vortex guide plate 160 is also provided on the inner wall of the tank body 100, and the vortex guide plate 160 is used to guide the reaction materials to form a vortex, promote efficient mixing, and enhance mass transfer and heat transfer. Further, the vortex guide plate 160 is also provided with a through hole, which can disperse the bubbles.

[0080] In some embodiments, in combination Figure 4 As shown, a plurality of porous sieve plates 170 are arranged on the inner wall of the tank body 100, and the plurality of porous sieve plates 170 are arranged in sequence and spaced apart along the height direction of the tank body 100. One end of each of the porous sieve plates 170 is fixed on the inner wall of the tank body 100, and the other end extends in the direction toward the center line of the tank body 100 and avoids the rotating guide cylinder 200.

[0081] It should be noted that the height of the material above the rotary guide tube 200 in the tank body 100 has a great influence on the mixing cycle of the material. This part is composed of a gas-liquid-solid dispersed phase, and its height varies with both the volume of the material in the tank body 100 and the amount of gas injected. The gas content of the material (the percentage of the gas phase in the volume of the gas-liquid mixture), the inoculation, feeding, sampling, discharge, continuous fermentation and other operations in the reaction process will affect the apparent volume of the material in the tank body 100 and its liquid level. In order to stabilize and adjust the height of the liquid level in the tank body 100, such as Figure 7 As shown, in the present invention, the semi-solid fermentation bioreactor also includes an air bag 500 and a pipeline 510. The air bag 500 is arranged below the liquid level in the tank body 100, and the pipeline 510 is arranged to be able to input fluid into the air bag 500 for controlling the volume of the air bag 500; it can be understood that the volume of the air bag 500 is changed by controlling the filling degree of the air bag 500, thereby adjusting the liquid level height of the reaction material in the tank body 100.

[0082] In the present utility model, the fluid input into the input airbag 500 for adjusting the filling degree of the airbag 500 can be a gas or a liquid. The gas can be, for example, compressed air. The advantage of adjusting the filling degree of the airbag 500 by inputting compressed air is that rapid adjustment can be achieved. The liquid can be, for example, water. The advantage of adjusting the filling degree of the airbag 500 by inputting water is that it can circulate while adjusting the filling degree of the airbag 500, and play a role in heat exchange for the reaction materials in the tank body 100.

[0083] In the present utility model, in order to avoid affecting the mass transfer and heat transfer of the reaction materials in the tank body 100 while adjusting the liquid level height of the reaction materials in the tank body 100 through the airbag 500, the airbag 500 is arranged in a structure with a fusiform longitudinal section in the height direction of the tank body 100, and the wall of the airbag 500 is made of an elastic polymer material that can withstand the fermentation sterilization temperature and pressure.

[0084] In some embodiments, in order to improve the regulation ability of the liquid level height of the reaction materials in the tank body 100 based on the airbag 500, a plurality of airbags 500 are provided, and the plurality of airbags 500 are evenly distributed in the tank body 100.

[0085] It should be noted that an appropriate height of the reaction materials is beneficial to prolong the residence time of the gas in the reaction materials and improve the utilization rate of the gas. Therefore, the height-diameter ratio of traditional air-lift reactors is usually 4 - 12, and the height of industrial production-scale reactors can even reach more than 30m. However, when the liquid level of the reaction materials in a large air-lift bioreactor is too high, the gas-liquid distribution is uneven, and during the circulation process of the reaction liquid, the pressure change amplitude borne by the microbial cells is relatively large. In addition, the static pressure of the liquid material is large, so the pressure at the outlet of the gas compressor must be increased, the power consumption of the gas compressor increases significantly, the pressure bearing capacity designed for the reactor is large, the manufacturing and installation costs of the tank body 100 are high, and the static pressure at the lower part of the reactor may directly affect the survival rate of the microbial cells, or the increase in gas solubility may affect the metabolic activity, thereby affecting the productivity and product quality. Therefore, on the premise of ensuring the effective volume, the height of the reactor can be reduced and the diameter of the tank body 100 can be increased, that is, the height-diameter ratio of the reactor is reduced. To ensure the material circulation of a semi-solid fermentation reactor with a small height-diameter ratio, a plurality of rotary guide cylinders 200 are arranged in the tank body 100, and the plurality of rotary guide cylinders 200 are evenly distributed in the tank body 100.

[0086] Furthermore, the outer shape of the reactor provided with a plurality of rotary guide cylinders 200 can be spherical; for the same volume, the area of the tank wall material required for the spherical tank body 100 is the least, and the pressure bearing capacity is stronger, and a relatively thin tank wall design can be adopted.

[0087] Such asFigure 7 A semi-solid fermentation bioreactor with a large diameter-height ratio provided by the present utility model; as Figure 8 is an open semi-solid fermentation bioreactor provided by the present utility model. In this open semi-solid fermentation bioreactor, the motor 110 is fixed through a horizontal fixed beam frame 104 horizontally arranged above the reactor.

[0088] The semi-solid fermentation bioreactor provided by the present utility model can implement closed semi-solid fermentation with less wastewater discharge, and utilize edible or feedable insoluble solid organic biomass, such as soybean dregs, wheat bran, rice bran, vinegar residues, distiller's grains, sauce residues, straw, etc., to produce protein through appropriate microbial fermentation.

[0089] The biological conversion and utilization of non-grain biomass such as lignocellulose are very important. Using the semi-solid fermentation bioreactor of the present utility model to implement the fermentation of insoluble solid organic biomass, while producing small molecule compounds and / or nutrient-rich microbial cells, the enzymes produced by microorganisms can also be synchronously separated and obtained.

[0090] Compared with solid-state fermentation, the semi-solid fermentation bioreactor provided by the present utility model can achieve closed and controllable semi-solid fermentation, is easy to control the contamination of miscellaneous bacteria, is suitable for pure bacteria fermentation and mixed bacteria fermentation with limited strains, and the quality control of products is stable; there is no need for loose large-particle carriers, the particle size of insoluble substrates is small, the steric hindrance is small, the surface area is larger, and it is more conducive to being utilized by microorganisms and enzymes; there is a large amount of free water, which provides a better reaction medium environment for enzymatic catalysis, the dispersion of substrates, enzymes, microbial cells and products is good, and the microenvironment difference of reaction materials is small; substrates with high moisture content do not need dehydration treatment, saving energy; filamentous fungi do not produce spores in the semi-solid fermentation environment, and the ineffective components of products are less; the reaction efficiency and the effective conversion and utilization rate of substrates are high, the substrate residues are less, and the proportion of target products is high; it is conducive to the post-treatment of fermentation materials and the separation of products, makes full use of fermentation products, and reduces the discharge of wastewater and solid waste.

[0091] In the semi-solid fermentation bioreactor provided by the present utility model, in order to reduce adhesion and corrosion, the inner wall of the tank body 100 and the surfaces of various components inside the tank body 100 can be coated with a material having hydrophobic properties, for example, it can be the self-assembled strongly adhesive copolymer film disclosed in the publication number "CN115612403 A".

[0092] In the present utility model, in order to facilitate the process parameters during fermentation, it is a conventional means in the art to set corresponding monitoring instruments on the tank body 100, and the present utility model will not elaborate here.

[0093] Correspondingly, the semi-solid fermentation bioreactor provided by the present utility model further includes one or more feedback control systems for regulating fermentation conditions and adjusting the volume of the culture or the liquid level height of the material. The feedback control system may, for example, include one or more sensors, or an on-line sampling and detection system for measuring one or more process parameters during fermentation; a calculation and analysis module for calculating and analyzing the process parameters to determine whether they are higher or lower than the preset values of the corresponding parameters; and an actuator for adjusting the process conditions to reach the preset values.

[0094] To ensure the stable progress of the fermentation process, corresponding auxiliary equipment, such as conventional equipment like a tail gas analysis system, a steam sterilization system, a heat exchange system, a gas supply system, etc., are common means in the art and are not elaborated herein for the present utility model.

[0095] The preferred embodiments of the present utility model have been described in detail above in conjunction with the accompanying drawings. However, the present utility model is not limited thereto. Within the scope of the technical concept of the present utility model, various simple modifications can be made to the technical solution of the present utility model. To avoid unnecessary repetition, the present utility model does not separately describe various possible combinations. But these simple modifications and combinations should also be regarded as the content disclosed by the present utility model and all fall within the protection scope of the present utility model.

Claims

1. A semi-solid fermentation bioreactor, characterized in that: The invention comprises a tank body (100) having a feeding port (101) and a discharging port (103), wherein a rotating guide cylinder (200) is arranged in the tank body (100), wherein the rotating guide cylinder (200) is arranged to be rotatable around its own axis, and a spiral belt (210) extending along the length direction of the rotating guide cylinder (200) is arranged on the inner wall and / or the outer wall of the rotating guide cylinder (200).

2. The semi-solid fermentation bioreactor according to claim 1, characterized in that: The rotary guide cylinder (200) is provided with one and is coaxially arranged with the tank body (100).

3. The semi-solid fermentation bioreactor according to claim 1, characterized in that: A plurality of the rotating flow guide cylinders (200) are provided, and the plurality of rotating flow guide cylinders (200) are evenly spaced and distributed in the tank body (100).

4. The semi-solid fermentation bioreactor according to claim 1, characterized in that: The spiral band (210) is arranged on both the inner wall and the outer wall of the rotating guide cylinder (200), and the spiral band (210) located on the inner wall of the rotating guide cylinder (200) and the spiral band (210) located on the outer wall of the rotating guide cylinder (200) have opposite rotation directions.

5. The semi-solid fermentation bioreactor according to claim 1, characterized in that: At least part of the wall of the rotary guide cylinder (200) is configured as a hollow structure.

6. The semi-solid fermentation bioreactor according to claim 1, characterized in that: A motor (110) is provided on the inner top of the tank body (100), and the motor (110) is used to drive the rotary guide cylinder (200) to rotate around its own axis.

7. The semi-solid fermentation bioreactor according to claim 6, characterized in that: A defoaming paddle (220) is arranged above the rotating flow guide cylinder (200), and the defoaming paddle (220) is driven by the motor (110) to rotate around the axis of the rotating flow guide cylinder (200).

8. The semi-solid fermentation bioreactor according to claim 1, characterized in that: The semi-solid fermentation bioreactor also includes a screw-belt propeller (300), which is coaxially inserted into the rotating guide tube (200) and driven to rotate around its own axis to promote the flow of materials in the rotating guide tube (200).

9. The semi-solid fermentation bioreactor according to any one of claims 1 to 8, characterized in that: A fixed flow guide cylinder (400) is arranged between the lower end of the rotating flow guide cylinder (200) and the inner bottom of the tank body (100); the fixed flow guide cylinder (400) is coaxially arranged with the rotating flow guide cylinder (200); a rim propeller (410) is arranged on the inner cylinder wall and / or the outer cylinder wall of the fixed flow guide cylinder (400); the rim propeller (410) is used to push the material to move along the axial direction of the fixed flow guide cylinder (400); and / or The semi-solid fermentation bioreactor also includes an air bag (500) and a pipeline (510), wherein the air bag (500) is arranged below the liquid level in the tank body (100), and the pipeline (510) is arranged to be able to input fluid into the air bag (500) for controlling the volume of the air bag (500).

10. The semi-solid fermentation bioreactor according to claim 9, characterized in that: The fixed flow guide cylinder (400) is an integrated cylinder or is composed of at least two segmented cylinders (401) combined along the axial direction of the tank body (100), and an annular gap (402) is provided between the axial directions of two adjacent segmented cylinders (401).

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