Fermentation tank

Abstract

The present invention discloses a fermentation tank, which includes a tank body and a stirring system, wherein the stirring system includes a stirring shaft, a turbine air collecting plate and a stirring aeration impeller. The stirring aeration impeller of the present invention is provided with a plurality of blades, and a flow guide channel is provided on the blades, and has both stirring function and aeration function. The stirring aeration impeller cooperates with the turbine air collecting plate and the stirring shaft to aerate at medium and low speeds and under the premise of low shear force requirements, so that the upper gas is dispersed into the solution, thereby improving the utilization efficiency of oxygen in the fermentation process, saving gas consumption, reducing energy consumption in large-scale fermentation processes, and saving costs. By improving the utilization efficiency of oxygen, the air intake is further reduced, and the rate of foaming in the fermentation liquid can also be reduced. In addition, the generated foam can be actively eliminated without the need to add a large amount of defoaming agent to eliminate the foam.

Description

Technical Field

[0001] The invention relates to a fermentation tank. Background Art

[0002] The schematic diagram of the fermentation tank currently used is as follows Figure 1 As shown, during the fermentation process, the gas supply is mainly carried out through a deep ventilation pipe, which is located at the bottom of the fermentation tank.

[0003] 1. Fermentation tank and accessories (accessories include temperature, pressure, pH, DO, measuring instruments (weighing or liquid level), defoaming electrodes, liquid level switches, sight glasses, sight lights, installation devices, spray balls, etc.): These instruments or devices are connected to the tank. Instrument accessories directly monitor the relevant data inside the tank and transmit them to the automatic control system in real time. Safety devices can generally be safety valves or bursting discs to protect the tank and prevent excessive pressure inside the tank. Spray balls are used to clean the inner wall of the tank.

[0004] 2. TCU system: TCU system refers to a temperature control unit, which is generally connected to the jacket of the tank body. The circulating pump inside the TCU continuously circulates the medium in the tank jacket and TCU, and the circulation direction is from bottom to top and from top to bottom of the jacket. A heating and cooling device is generally set in the TCU to heat / cool the circulating medium, so as to achieve the heating and cooling of the fermentation tank. The temperature in the fermentation tank can be controlled in real time through the automatic control system. Furthermore, the heating and cooling device of the TCU can be two plate heat exchangers, one of which is used to heat the circulating medium and the other is used to cool the circulating medium. The other side of the heated plate heat exchanger is heated by industrial steam, and the other side of the cooled plate heat exchanger is cooled by cooling water or chilled water.

[0005] 3. Feeding system: including basic culture medium, inoculation, acid / alkali, defoaming, culture medium, etc. These media are added to the fermenter once, intermittently or continuously through the feeding system. There are generally many ways to control feeding. The feeding with a relatively small capacity is added to the fermenter by means of a bench scale + peristaltic pump + four-valve group. The feeding control is controlled by the automatic control system according to the data feedback from the relevant instruments of the fermenter. The feeding with a relatively large capacity is generally connected to the fermenter by a pipe through a feeding tank (or feeding bag). The amount of feeding liquid added is controlled by a flow meter and a regulating valve before entering the fermenter. The feeding amount is controlled by the automatic control system through the instrument data of the fermenter to control the opening of the regulating valve in real time to adjust the feeding flow.

[0006] 4. Air intake system: It is a system for introducing gas into the bottom (deep layer) of the fermentation tank. Deep ventilation includes a gas distributor installed at the bottom of the fermentation tank (the distributor is connected to the air system outside the fermentation tank through a pipeline). It mainly introduces gas into the fermentation tank and distributes bubbles into the fermentation liquid through the gas distributor. Generally, the ventilation pipeline is equipped with a separate gas filter, and the front end of the filter is connected to a gas flow and a regulating valve to control the flow of gas introduced. These gases can be compressed air, oxygen, etc. The automatic control system feeds back the data of the fermentation tank instrument to the air intake regulating valve and flow meter in real time to adjust the intake flow in real time.

[0007] 5. Exhaust system: It is used to discharge the waste gas generated by cell metabolism in the fermentation tank and control the pressure inside the fermentation tank through the exhaust gas regulating valve. The automatic control system controls the opening of the exhaust gas regulating valve through real-time feedback of the instrument data of the fermentation tank to maintain a constant pressure value inside the fermentation tank.

[0008] 6. Stirring system. The stirring system includes mechanical stirring and magnetic stirring. It is to make the various media inside the fermenter mix evenly. The heat exchange of the jacket can maintain the uniformity of the temperature inside the fermenter to achieve the required mass transfer and heat transfer effect. The automatic control system adjusts the stirring speed in real time through the data of the fermenter instrument to achieve the required mass transfer and heat transfer effect inside the fermenter, and records the data of the instrument in real time. Although there are many forms of fermenter agitators at present, they are all classic and commonly used stirring blade types, mainly divided into axial flow stirring (such as propulsion blades, inclined blade blades, etc.) and radial flow agitators (such as hollow half-tube blades, six straight blade disc blades, etc.).

[0009] 7. Sampling system: The sampling system is to take out a small amount of fermentation liquid from the fermenter through a sampling device connected to the fermenter body. It is used to analyze some indicators offline and simply judge the fermentation status in the fermenter.

[0010] 8. CIP system: The CIP system is to clean the fermentation tank, and is integrated with the pipes and valves in the fermentation tank system. The CIP system is connected to a CIP station, which provides cleaning liquid to the fermentation tank. The inner wall of the fermentation tank and its internal tank accessories, stirring, air intake system, feeding system, sampling system, exhaust system and harvesting pipeline all need to be cleaned by the cleaning liquid of the CIP station. This function is achieved by controlling the valve switch of the CIP pipeline and the cleaning medium of the CIP system through the automatic control system.

[0011] 9. SIP system: To ensure the sterility of the fermentation tank, feeding system, air intake system, exhaust system, tail gas system and sampling system, the relevant pipes, valves and instruments are sterilized by pure steam. Each cold point is equipped with a low-point drain and temperature probe detection. The SIP process is completed by controlling the relevant valves and instruments through the automatic control system.

[0012] 10. Automatic control system: It includes software and hardware parts, including servers, operation stations, PLCs, touch screens, frequency converters, valve islands, etc. The electrical hardware connects the upper-level automatic control components with valve instruments or stirring components on site, and the various subsystems of the fermentation tank system are coordinated and operated in an orderly manner through the control of the automatic control system.

[0013] The problems existing in the prior art are as follows:

[0014] 1. Too much foam during the fermentation process will occupy a large amount of top space, reduce the utilization rate of the fermentation tank, and clog the exhaust gas filter, causing adverse effects such as fermentation failure and liquid escape. At present, the foam can only be eliminated by adding defoaming agents or adding defoaming blades above the liquid surface. Although adding defoaming agents to eliminate foam has a short-term defoaming effect, it is necessary to continuously add defoaming agents during the fermentation process to achieve the purpose of controlling the foam. The addition of a large amount of defoaming agents will increase the burden on downstream purification and have an adverse effect on the metabolism of cells during the fermentation process. The purpose of real defoaming cannot be achieved by adding defoaming blades above the liquid surface. Only the foam that contacts the blades can be eliminated, and a large amount of foam in other parts cannot be eliminated. In addition, due to the addition of defoaming blades, the balance of the stirring shaft is more challenged.

[0015] 2. The gas consumption during the fermentation process is too high, especially after industrialization. Too much gas consumption will consume a lot of energy to produce compressed air or oxygen for the fermentation tank. On the other hand, due to the very low solubility of oxygen in the fermentation liquid, a large amount of oxygen entering the fermentation liquid is not dissolved or used and is discharged from the fermentation tank. When the compressed air passes through the fermentation tank, only about 10% of the oxygen will be dissolved or used, and most of the oxygen will be discharged through the exhaust system. Therefore, how to improve the utilization efficiency of oxygen and reduce the consumption of oxygen or compressed air is an urgent problem to be solved in the fermentation field.

[0016] 3. The existing technology is applied in a high-speed and high-shear environment, while the fermenter is used to culture microbial cells or animal cells, which requires low shear force to achieve better mixing and mass transfer. The speed range generally used by the fermenter is medium and low.

[0017] High and low speeds are generally defined by the tip speed of the impeller when it rotates. The tip speed of the impeller in the prior art is generally 8-15m / s. The tip speed of the impeller in the fermentation tank is generally below 6m / s, and the maximum will not exceed 8m / s.

[0018] Therefore, how to achieve the dispersion of the upper gas into the solution at medium and low rotation speeds and under the premise of low shear force requirements is a technical problem that needs to be urgently solved in this field. Summary of the invention

[0019] The technical problem to be solved by the present invention is to provide a fermentation tank in order to overcome the defects in the prior art.

[0020] The present invention solves the above technical problems through the following technical solutions:

[0021] A fermentation tank, comprising a tank body and a stirring system, wherein the stirring system comprises:

[0022] A stirring shaft is disposed in the tank body, the stirring shaft is provided with a first fluid channel extending axially, and the stirring shaft is provided with a fluid inlet communicating with the first fluid channel;

[0023] A turbine air collecting plate, comprising a shell and a guide vane, wherein the shell is sleeved on the outside of the stirring shaft, the diameter of the shell gradually decreases along a first direction, the first direction is parallel to the axial direction of the stirring shaft, one side of the guide vane is connected to the stirring shaft, and the other side is connected to the shell, the guide vane is spirally arranged along the first direction, the guide vane, the stirring shaft, and the shell are enclosed to form a guide channel, the guide channel is communicated with the fluid inlet, and one end of the shell away from the bottom of the tank body is set to be open and is always located above the working liquid level in the tank body;

[0024] A stirring and aerating impeller is installed at one end of the stirring shaft close to the bottom of the fermentation tank, the stirring and aerating impeller includes a plurality of blades, a second fluid channel connected to the first fluid channel is opened on the blade, an outlet of the second fluid channel is arranged on the side of the blade opposite to the forward rotation direction of the stirring and aerating impeller, and an opening direction of the outlet of the second fluid channel is the tangential direction of the stirring and aerating impeller.

[0025] Preferably, the shell is coaxially arranged with the stirring shaft, and / or one end of the shell close to the bottom of the tank body is arranged to be closed.

[0026] Preferably, the guide vane comprises a first guide vane and a second guide vane, and the first guide vane and the second guide vane are staggered and spirally arranged along a first direction.

[0027] Preferably, the number of the fluid inlets is plural and they are evenly distributed along the circumference of the stirring shaft.

[0028] Preferably, the stirring shaft is a hollow shaft, and the hollow part thereof serves as the first fluid channel.

[0029] Preferably, the stirring shaft is a sandwich shaft structure formed by a solid shaft and a hollow tube with a larger diameter, and the sandwich is the first fluid channel.

[0030] Preferably, a trumpet-shaped jet baffle is installed around the outlet of the second fluid channel.

[0031] Preferably, the number of the blades is 6 and they are evenly distributed.

[0032] Preferably, the blade is in the shape of a straight plate.

[0033] Preferably, the blade is in a C-shaped arc shape, and the direction of the arc opening is the forward rotation direction of the stirring and aerating impeller.

[0034] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0035] The positive and progressive effects of the present invention are: the fermentation tank of the present invention includes a tank body and a stirring system, and the stirring system includes a stirring shaft, a turbine air collecting plate and a stirring aeration impeller. The stirring aeration impeller of the present invention is provided with a plurality of blades, and a guide channel is provided on the blades, and has both stirring function and aeration function. The stirring aeration impeller cooperates with the turbine air collecting plate and the stirring shaft to aerate at medium and low speeds and under the premise of low shear force requirements, so that the upper gas is dispersed into the solution, thereby improving the utilization efficiency of oxygen in the fermentation process, saving gas consumption, reducing energy consumption in large-scale fermentation processes, and saving costs. By improving the utilization efficiency of oxygen, the air intake is further reduced, and the rate of foaming in the fermentation liquid can also be reduced. In addition, the generated foam can be actively eliminated without the need to add a large amount of defoaming agent to eliminate the foam. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of a fermentation tank in the prior art.

[0037] Figure 2 Schematic diagram of a fermentation tank according to a preferred embodiment of the present invention.

[0038] Figure 3 This is a schematic diagram of the connection relationship between the turbine gas collecting plate and the stirring shaft in a preferred embodiment of the present invention.

[0039] Figure 4 The figure is a schematic diagram of the connection relationship between the stirring aeration impeller and the stirring shaft according to a preferred embodiment of the present invention.

[0040] Figure 5 This is a schematic diagram of the connection relationship between the stirring aeration impeller and the stirring shaft in another form of a preferred embodiment of the present invention.

[0041] Description of reference numerals:

[0042] Tank 1

[0043] Temperature control unit 2

[0044] Feeding system 3

[0045] Intake system 4

[0046] Exhaust system 5

[0047] Mixing system 6

[0048] Stirring shaft 61

[0049] First fluid channel 611

[0050] Fluid inlet 612

[0051] Turbine air collecting plate 62

[0052] Housing 621

[0053] Guide plate 622

[0054] First guide plate 6221

[0055] Second guide piece 6222

[0056] Diversion channel 623

[0057] Mixing aeration impeller 63

[0058] Blade 631

[0059] Second fluid channel 632

[0060] Sampling system7 DETAILED DESCRIPTION

[0061] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] It should be noted that in the claims and description of this patent, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0063] like Figure 2-Figure 5 As shown, this embodiment discloses a fermentation tank, which includes a tank body 1, a temperature control unit 2, a feeding system 3, an air intake system 4, an exhaust system 5, a stirring system 6, a sampling system 7, a CIP system, a SIP system, and an automatic control system. The stirring system 6 includes a stirring shaft 61, a turbine air collecting plate 62 and a stirring aeration impeller 63.

[0064] The stirring shaft 61 is arranged in the tank body 1, and the axial direction of the stirring shaft 61 is the same as the depth direction of the tank body 1 (the extension direction of the side wall of the tank body 1). The stirring shaft 61 is provided with an axially extending first fluid channel 611, and the stirring shaft 61 is provided with a fluid inlet 612 connected to the first fluid channel 611.

[0065] The turbine gas collecting plate 62 includes a shell 621 and a guide vane 622. The shell 621 is sleeved on the outside of the stirring shaft 61. The diameter of the shell 621 is along the first direction ( Figure 2 The X direction shown in the figure (i.e., the direction from top to bottom) gradually decreases, that is, the shell 621 is in a truncated cone shape with a larger top and a smaller bottom. The first direction is parallel to the axial direction of the stirring shaft 61. One side of the guide plate 622 is connected to the stirring shaft 61, and the other side is connected to the shell 621. The guide plate is spirally arranged along the first direction. The guide plate, the stirring shaft 61, and the shell 621 are surrounded to form a guide channel 623. The guide channel 623 is connected to the fluid inlet 612. The end of the shell 621 away from the bottom of the tank body 1 ( Figure 3 The upper end of the turbine gas collecting plate 62 is set to an opening and is configured to be always located above the working liquid level in the tank body 1 to ensure that the turbine gas collecting plate 62 can always collect the gas and bubbles above the working liquid level.

[0066] The stirring and aerating impeller 63 has both stirring and aerating functions, and is installed at one end of the stirring shaft 61 close to the bottom of the fermentation tank. The stirring and aerating impeller 63 includes a plurality of blades 631, and a second fluid channel 632 connected to the first fluid channel 611 is opened on the blade 631. The outlet of the second fluid channel 632 is arranged on the side of the blade 631 opposite to the forward rotation direction of the stirring and aerating impeller 63, and the opening direction of the outlet of the second fluid channel 632 is the tangential direction of the stirring and aerating impeller 63.

[0067] The turbine air collecting plate 62 rotates with the stirring shaft 61 and can absorb the surrounding gas or foam. When rotating clockwise, the surrounding gas and foam will be sucked into the guide channel 623 and enter the first fluid channel 611 in the stirring shaft 61 through the fluid inlet 612. When rotating counterclockwise, an outward centrifugal force will be generated, which can suck up the liquid of the lower stirring and aeration impeller 63 to achieve the purpose of cleaning the channel and the inside of the impeller. Since negative pressure will be generated on the back of the blade 631 when the stirring and aeration impeller 63 rotates forward, the gas and foam in the first guide channel 623 can be drawn out through the second guide channel 623. On the other hand, since the forward rotation of the stirring and aeration impeller 63 will also generate centrifugal force, the gas and foam in the first guide channel can also be thrown out by the action of centrifugal force.

[0068] According to experimental tests, a separate aeration wheel without stirring capability cannot aerate at medium and low speeds. The stirring aeration impeller 63 of this embodiment is provided with a plurality of blades 631, and a guide channel 623 is provided on the blades 631, which has both stirring and aeration functions. The stirring aeration impeller 63 cooperates with the turbine air collecting plate 62 and the stirring shaft 61 to aerate at medium and low speeds under the premise of low shear force requirements, so that the upper gas is dispersed into the solution, thereby improving the utilization efficiency of oxygen in the fermentation process, saving gas consumption, reducing energy consumption in large-scale fermentation processes, and saving costs. By improving the utilization efficiency of oxygen, the air intake is further reduced, and the rate of foaming in the fermentation liquid can also be reduced. In addition, the generated foam can be actively eliminated without the need to add a large amount of defoaming agent to eliminate the foam.

[0069] Furthermore, in this embodiment, one end of the shell 621 close to the bottom of the tank 1 is set to be closed, and the shell 621 is coaxially arranged with the stirring shaft 61 .

[0070] The guide vane 622 includes a first guide vane 6221 and a second guide vane 6222 , and the first guide vane 6221 and the second guide vane 6222 are staggered and spirally arranged along a first direction.

[0071] There are multiple fluid inlets 612 that are evenly distributed along the circumference of the stirring shaft 61 .

[0072] In this embodiment, any of the above-mentioned structural forms can improve the efficiency of the turbine gas collecting plate 62 in sucking the surrounding gas or foam and sending it into the first guide channel 623 in the stirring shaft 61.

[0073] Furthermore, in this embodiment, the stirring shaft 61 is a hollow shaft, and the hollow part thereof is the first fluid channel 611. The hollow stirring shaft 61 not only has a simple structure, but also can reasonably utilize space, and the stirring shaft 61 can be miniaturized.

[0074] In other alternative embodiments, the stirring shaft 61 is a sandwich shaft structure formed by sleeved a hollow tube with a larger diameter outside a solid shaft, and the sandwich is the first fluid channel 611. The stirring shaft 61 of this structural form is easy to produce and assemble.

[0075] Furthermore, in this embodiment, a trumpet-shaped jet baffle is installed around the outlet of the second fluid channel 632. In order to make the impeller have a self-cleaning function, this baffle can be a circular trumpet mouth, or a variety of forms such as an eight-shaped groove. The purpose is that when the impeller needs to achieve self-cleaning, the impeller will reverse, so that the trumpet mouth design can collect the cleaning water and the positive pressure of the rotation will allow the liquid to flow back into the first fluid channel 611 inside the stirring shaft 61 and the upper turbine air collecting plate 62. As mentioned above, the turbine air collecting plate 62 also has a certain suction force, which can achieve the purpose of internal self-cleaning. In order to achieve the self-cleaning function of the impeller, the second fluid channel 632 of the stirring aeration impeller 63 of the lower layer also needs to be curved. On the one hand, it can increase the centrifugal force of the gas being thrown out during aeration. On the other hand, when the impeller reverses, there can be a certain suction force to improve the cleaning efficiency.

[0076] In this embodiment, the number of blades 631 is 6 and they are evenly distributed. The blades 631 are in the shape of straight plates.

[0077] The blade 631 is in a C-shaped arc shape, and the direction of the arc opening is the forward rotation direction of the stirring and aerating impeller 63 .

[0078] In this embodiment, the number of blades 631 is designed to be 6, which can simplify the structure and save costs while ensuring the efficiency of stirring and aeration. The straight blade 631 has a simple structure and is easy to install; while the C-shaped arc blade 631 has the advantage of further improving the efficiency of stirring and aeration.

Claims

1. A fermentation tank, comprising a tank body and a stirring system, characterized in that: The stirring system comprises: A stirring shaft is disposed in the tank body, the stirring shaft is provided with a first fluid channel extending axially, and the stirring shaft is provided with a fluid inlet communicating with the first fluid channel; A turbine air collecting plate, comprising a shell and a guide vane, wherein the shell is sleeved on the outside of the stirring shaft, the diameter of the shell gradually decreases along a first direction, the first direction is parallel to the axial direction of the stirring shaft, one side of the guide vane is connected to the stirring shaft, and the other side is connected to the shell, the guide vane is spirally arranged along the first direction, the guide vane, the stirring shaft, and the shell are enclosed to form a guide channel, the guide channel is communicated with the fluid inlet, and one end of the shell away from the bottom of the tank body is set to be open and is always located above the working liquid level in the tank body; a stirring aeration impeller, mounted at one end of the stirring shaft close to the bottom of the fermentation tank, the stirring aeration impeller comprising a plurality of blades, the blades being provided with a second fluid channel connected to the first fluid channel, the outlet of the second fluid channel being arranged on the side of the blade opposite to the forward rotation direction of the stirring aeration impeller, and the opening direction of the outlet of the second fluid channel being the tangential direction of the stirring aeration impeller; The guide vane comprises a first guide vane and a second guide vane, wherein the first guide vane and the second guide vane are staggered and spirally arranged along a first direction; A trumpet-shaped jet baffle is installed around the outlet of the second fluid channel.

2. The fermentation tank according to claim 1, characterized in that The shell is coaxially arranged with the stirring shaft, and / or one end of the shell close to the bottom of the tank body is arranged to be closed.

3. The fermentation tank according to claim 1, characterized in that The number of the fluid inlets is multiple and evenly distributed along the circumference of the stirring shaft.

4. The fermentation tank according to claim 1, characterized in that The stirring shaft is a hollow shaft, and its hollow part is the first fluid channel.

5. The fermentation tank according to claim 1, characterized in that The stirring shaft is a sandwich shaft structure formed by sleeved a hollow tube with a larger diameter outside a solid shaft, and the sandwich is the first fluid channel.

6. The fermentation tank according to claim 1, characterized in that The number of the blades is 6 and they are evenly distributed.

7. The fermentation tank according to claim 1, characterized in that The blade is in the shape of a straight plate.

8. The fermentation tank according to claim 1, characterized in that The blade is in a C-shaped arc shape, and the direction of the arc-shaped opening is the forward rotation direction of the stirring aeration impeller.

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