Fermentation system with adjustable pH value

Abstract

The invention discloses a fermentation system with an adjustable pH value, and belongs to the technical field of fermentation equipment.The fermentation system comprises a fermentation tank, an alkali liquor conveying system and a temporary storage tank used for storing alkali liquor, the alkali liquor conveying system comprises an atomization spraying device, a liquor conveying pipe and a liquor supply pump, the atomization spraying device is installed above the fermentation liquor level in the fermentation tank, and the liquor conveying pipe is connected with the atomization spraying device; the atomization spraying device is communicated with the temporary storage tank through the liquid feeding pipe, and the liquid supply pump is arranged on the liquid feeding pipe. Alkali liquor in the temporary storage tank can be conveyed to the atomization spraying device through the liquor supply pump and the liquor conveying pipe, then atomized alkali liquor is conveyed into the fermentation tank through the atomization spraying device, the alkali liquor is evenly dispersed on the fermentation liquor surface of the fermentation tank, the added alkali liquor is rapidly and evenly dispersed, the situation that the local pH value is too high can be avoided, and target bacteria can be killed; the problem that the temperature of a local area is too high in the dilution process of the concentrated alkali liquor in the fermentation tank to influence the growth of strains is solved, and fermentation is further facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of fermentation equipment, and particularly to a fermentation system with adjustable pH value. Background Art

[0002] During the fermentation process of many organic acid products such as lactic acid, acetic acid, propionic acid, citric acid, pyruvic acid, butyric acid, malic acid, fumaric acid, succinic acid, α-ketoglutaric acid, tartaric acid, gluconic acid, itaconic acid, kojic acid, and long-chain dicarboxylic acid, due to the continuous acid production by microorganisms, as the organic acids accumulate, the pH value of the fermentation broth continuously decreases. When the organic acids accumulate to a certain extent, it will affect the growth and reproduction of microorganisms, even stop growing and eventually die. Supplementing acid and alkali during the fermentation process can, to a certain extent, adjust the pH value during the fermentation process, promote the continuous growth and reproduction of microorganisms, effectively induce the microorganisms to continue producing acid, and improve the fermentation efficiency and yield. Generally, the method of supplementing alkali is to directly add the alkali solution into the fermentation tank through an electromagnetic valve control, but this method is very likely to cause too high local pH value during the addition of strongly alkaline alkali solutions (such as sodium hydroxide, potassium hydroxide, etc.), killing the target bacteria. At the same time, the local area temperature is too high during the dilution process of the concentrated alkali solution in the fermentation tank, affecting the growth of the bacterial species, resulting in an extended fermentation cycle and seriously affecting the fermentation efficiency. Summary of the Invention

[0003] The object of the present invention is to solve the above technical problems and provide a fermentation system with adjustable pH value. This system uses an atomizing nozzle spraying method to add the alkali solution, enabling the rapid and uniform dispersion of the added alkali solution, avoiding the problems of too high local pH value and overheating of the local area temperature, and being more conducive to fermentation.

[0004] To achieve the above object, the present invention provides the following solution: The present invention discloses a fermentation system with adjustable pH value, including a fermentation tank, an alkali solution delivery system, and a temporary storage tank for storing the alkali solution. The alkali solution delivery system includes an atomizing spraying device, a liquid delivery pipe, and a liquid supply pump. The atomizing spraying device is installed above the fermentation liquid level in the fermentation tank. The atomizing spraying device is connected to the temporary storage tank through the liquid delivery pipe, and the liquid supply pump is arranged on the liquid delivery pipe.

[0005] Preferably, a stirring device for stirring the fermentation liquid is provided on the fermentation tank. The stirring device includes a vertically arranged stirring shaft, and stirring blades are provided on the stirring shaft.

[0006] Preferably, the atomizing spraying device includes an annular pipe. The annular pipe is coaxially sleeved outside the stirring shaft. The diameter of the annular pipe is larger than the diameter of the circumcircle where the stirring blades are located. Atomizing nozzles are uniformly arranged on the annular pipe, and the annular pipe is connected to the liquid delivery pipe.

[0007] Preferably, a notch is provided on the annular pipe, and the atomizing nozzles are arranged from one end of the notch of the annular pipe to the other end.

[0008] Preferably, the atomizing nozzle is a rotary nozzle.

[0009] Preferably, the rotary nozzle is an automatic rotary nozzle.

[0010] Preferably, the automatic rotary nozzle includes a connector, a rotating head, and an atomizing nozzle. One end of the connector is connected to the liquid supply pipe, the other end of the connector is rotatably connected to the rotating head, the atomizing nozzle is circumferentially arranged on the rotating head, and the atomizing nozzle drives the rotating head to rotate by the reaction force of the ejected liquid.

[0011] Preferably, the height of the annular pipe is adjustable.

[0012] Preferably, the liquid supply pump is a screw pump.

[0013] Preferably, a pH detector is provided on the fermentation tank, and a flow regulating valve is provided between the liquid supply pipe and the temporary storage tank.

[0014] The present invention has achieved the following technical effects compared with the prior art:

[0015] In the fermentation system with adjustable pH value of the present invention, the lye in the temporary storage tank can be sent to the atomizing spraying device through the liquid supply pump and the liquid supply pipe, and then the atomizing spraying device transports the atomized lye into the fermentation tank, so that the lye is evenly dispersed on the fermentation liquid surface of the fermentation tank, enabling the added lye to be quickly dispersed and evenly distributed, avoiding the problem that the local pH value is too high to kill the target bacteria, and the problem that the local temperature is too high during the dilution process of the concentrated lye in the fermentation tank affects the growth of the bacterial species, thereby being more conducive to fermentation. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a schematic structural diagram of the fermentation system with adjustable pH value in this embodiment;

[0018] Figure 2 It is a schematic cross-sectional structure diagram of the fermentation tank (without notch on the annular pipe) in this embodiment;

[0019] Figure 3 It is a schematic structural diagram of the straight-head atomizing nozzle in this embodiment;

[0020] Figure 4 It is a schematic cross-sectional structure diagram of the fermenter (ring pipe with a notch) in this embodiment;

[0021] Figure 5 It is a schematic structure diagram of the automatic rotary atomizing nozzle in this embodiment;

[0022] Figure 6 It is a schematic diagram of the OD600 change value in this embodiment;

[0023] Figure 7 It is a schematic diagram of the total organic acid change value in this embodiment;

[0024] Figure 8 It is a schematic diagram of the Nisin titer change value in this embodiment.

[0025] Explanation of reference numerals: 1, fermenter; 2, storage tank; 3, spraying device; 4, liquid delivery pipe; 5, liquid supply pump; 6, pH detector; 7, driving motor; 8, stirring shaft; 9, stirring blade; 10, ring pipe; 11, atomizing nozzle; 12, automatic rotary nozzle; 13, connector; 14, rotating head; 15, atomizing nozzle; 16, flow regulating valve. Specific implementation manners

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] This embodiment provides a fermentation system with adjustable pH value, as Figures 1 to 8 shown, including a fermenter 1, a storage tank 2 and an alkali solution delivery system. The alkali solution delivery system includes an atomizing spraying device 3, a liquid delivery pipe 4 and a liquid supply pump 5. The atomizing spraying device 3 is installed above the fermentation liquid level in the fermenter 1. The atomizing spraying device 3 is communicated with the storage tank 2 through the liquid delivery pipe 4. The liquid supply pump 5 is arranged on the liquid delivery pipe 4. The storage tank 2 is used to store alkali solution. After starting the liquid supply pump 5, the alkali solution in the storage tank 2 can be sent to the atomizing spraying device 3 through the storage tank 4, and then the atomizing spraying device 3 transports the atomized alkali solution into the fermenter 1, so that the alkali solution is evenly dispersed on the fermentation liquid surface of the fermenter 1, enabling the added alkali solution to be quickly and evenly dispersed, avoiding the problem that the local pH value is too high to kill the target bacteria, and the problem that the local area temperature is too high during the dilution process of the concentrated alkali solution in the fermenter affects the growth of the bacterial strain, and then being more beneficial to fermentation.

[0028] The specific process of the fermentation system is as follows: After the lye is prepared, it is sterilized, filtered, and then pumped into the temporary storage tank 2. According to the detection of the pH value change of the fermentation tank 1, the liquid supply pump 5 is controlled, and the lye is pumped into the fermentation tank 1 through the atomizing spray device 3 to maintain the pH value stability of the fermentation broth.

[0029] In one embodiment, as Figures 1 to 8 shown, the fermentation tank 1 is provided with a stirring device for stirring the fermentation liquid. The stirring device includes a stirring shaft 8 arranged vertically, and stirring blades 9 are provided on the stirring shaft 8.

[0030] In one embodiment, as Figures 1 to 8 shown, the atomizing spray device 3 includes an annular pipe 10. The annular pipe 10 is coaxially sleeved outside the stirring shaft 8. The diameter of the annular pipe 10 is larger than the diameter of the circumscribed circle where the stirring blades 9 are located. Atomizing nozzles 11 are uniformly arranged on the annular pipe 10, and the annular pipe 10 is communicated with the liquid supply pipe 4. The setting method of the annular pipe 10 can avoid the atomized lye spraying onto the stirring blades 9, and then the problem of too high local pH value caused by the confluence of the stirring blades 9 and the stirring shaft 8 on the fermentation liquid surface. Preferably, the height distance between the atomizing nozzle 11 and the fermentation liquid surface is 0.5 - 2m. The inner wall diameter of the fermentation tank 1 is d 1 , the diameter of the circumscribed circle where the stirring blades 9 are located is d 2 , the diameter of the annular pipe 10 is d 3 , d 2 < d 3 < d 1 , preferably d 3 = (d 1 + d 2 ) / 2. The stirring shaft 8 is rotated through a driving mechanism. Preferably, the driving mechanism is a driving motor 7. The driving motor 7 is installed on the top of the fermentation tank 1 and is located outside the fermentation tank 1.

[0031] In one embodiment, as Figures 1 to 8 shown, the annular pipe 10 is provided with a notch, and the atomizing nozzles 11 are arranged from one end of the notch of the annular pipe 10 to the other end. The annular pipe 10 can be conveniently installed through the notch. The notch is an arc-shaped notch, and the arc-shaped notch is usually not more than 1 / 4 of the annular pipe 10.

[0032] In one embodiment, as Figures 1 to 8 shown, the atomizing nozzle 11 adopts an ordinary straight-head nozzle. Both the annular pipe 10 without a notch and the annular pipe 10 with a notch can adopt straight-head nozzles. The angle of the spray holes of the straight-head nozzle needs to be set according to specific circumstances. The number of straight-head nozzles is set on the annular pipe 10 according to the fermentation requirements (mainly according to factors such as fermentation acid production amount and lye concentration, etc.). Preferably, there are 10 - 50 straight-head nozzles, which are evenly arranged on the annular pipe 10.

[0033] In one embodiment, asFigures 1 to 8 As shown, the atomizing nozzle 11 is a rotary nozzle. Both the seamless annular pipe 10 and the notched annular pipe 10 can adopt rotary nozzles. The rotary nozzle can rotate 360° for spraying, providing a complete spherical spraying coverage. The formed spraying range can be significantly larger than that of ordinary straight nozzles, thus reducing the number of atomizing nozzles 11. For an annular pipe 10 with the same diameter, if 10 - 50 straight nozzles are used, only 3 - 8 atomizing nozzles 11 are needed, preferably 4. Generally, the rotary nozzle is more compatible with the notched annular pipe 10, effectively filling the problem that there is no spraying coverage at the notch of the notched annular pipe 10 where there is no nozzle.

[0034] In one embodiment, as Figures 1 to 8 shown, the rotary nozzle adopts an automatic rotary nozzle 12. The automatic rotary nozzle 12 is a nozzle that uses the reaction force of the liquid to drive the rotary motion, which can rotate automatically 360° without the need for an external motor or gear to provide power.

[0035] Furthermore, in one embodiment, as Figures 1 to 8 shown, the automatic rotary nozzle 12 includes a connecting head 13, a rotary head 14, and an atomizing nozzle 15. One end of the connecting head 13 is connected to the liquid delivery pipe 4 (thread connection can be used), and the other end of the connecting head 13 is rotatably connected to the rotary head 14. A plurality of atomizing nozzles 15 are circumferentially arranged on the rotary head 14. The atomizing nozzle 15 uses the reaction force of the ejected liquid to drive the rotary head 14 to rotate. Specifically, the atomizing nozzle 15 needs to have an angle with the vertical direction, and at the same time, the spraying directions of the plurality of atomizing nozzles 15 are opposite to the rotation direction of the rotary head 14. When the atomizing nozzle 15 sprays out the lye, under the reaction of the liquid, it will push the rotary head 14 to rotate.

[0036] In one embodiment, as Figures 1 to 8 shown, the height of the annular pipe 10 is adjustable, and then the height distance between the atomizing nozzle 11 and the fermentation liquid surface can be adjusted. Preferably, the annular pipe 10 can automatically rise with the height of the fermentation liquid surface and maintain a certain distance to avoid flowing into the fermentation liquid after spraying on the tank wall of the fermentation tank 1 and the stirring blade 9.

[0037] In one embodiment, as Figures 1 to 8 shown, the liquid supply pump 5 is a screw pump. Of course, other types of pumps can also be replaced according to needs.

[0038] In one embodiment, as Figures 1 to 8As shown in the figure, a pH detector 6 is provided on the fermenter 1 to detect the pH value of the fermentation broth in the fermenter 1. A flow regulating valve 16 is provided between the liquid supply pipe 4 and the temporary storage tank 2, and the flow regulating valve 16 is used to regulate the alkali liquor delivery volume. According to the change of the pH value of the fermentation broth, the amount added to the fermentation broth can be controlled through the flow regulating valve 16. Generally speaking, the total addition ratio is 3-5% of the fermentation broth, and the temperature is 25-32 degrees Celsius. The alkali liquor can be configured into an alkali liquor with a concentration of 10-40%, preferably 15-30%. Stir evenly to make it completely dissolve, and then sterilize it. The sterilization temperature can be selected from 110-130°C, preferably 115-121°C. The sterilization time is 10-40 min, preferably 20-30 min. Finally, filter to remove the residue. Pump the sterilized alkali liquor into the temporary storage tank 2, and control the temperature of the alkali liquor to be maintained at 20-40°C, preferably 30-35. Preferably, a liquid inlet is provided at the upper part of the side wall of the temporary storage tank 2 for pumping in the alkali liquor. The liquid outlet of the temporary storage tank 2 is located at the lower part of the side wall. The liquid outlet is connected to the liquid supply pipe 4, and the flow regulating valve 16 is arranged on the liquid outlet. A drain port is provided at the bottom of the temporary storage tank 2, and the unused alkali liquor in the temporary storage tank 2 can be drained when not in use.

[0039] In one embodiment, as Figures 1 to 8 shown, the reference operation examples are as follows:

[0040] Starch is added with water in the fermenter 1, the concentration is adjusted to 15-25%, the pH is 5-6, the temperature is 35-45°C, and heat-resistant α-amylase is added for enzymatic hydrolysis and liquefaction. The temperature of the slurry is 95-100°C, and the maintenance time is 1-2 h. Then the pH value is adjusted to 4-6, and saccharifying enzyme is added for enzymatic hydrolysis and saccharification. The enzymatic hydrolysis time is 30-40 h, and when the glucose syrup content reaches 30-35%, the enzymatic hydrolysis is stopped.

[0041] After adding culture media such as sucrose, yeast extract, potassium dihydrogen phosphate, peptone, etc., sterilization treatment is carried out. The sterilization temperature is 110-125°C, and the time is 30-90 min.

[0042] After the sterilization is completed, the pH of the fermentation broth is adjusted to 6.5-7.5, and lactic acid bacteria (the lactic acid bacteria is Lactococcus lactis subsp. lactis, CICC6242) are inoculated for fermentation. The fermentation temperature is 30-35°C. During the fermentation process, the sterilized 25% sodium hydroxide solution in the temporary storage tank 2 is injected into the fermenter 1 to control the pH value at 7.0-7.2, and the fermentation cycle is 30-50 h. When the sugar content in the fermentation broth is less than 0.1% and the pH value no longer decreases during continuous fermentation, the fermentation can be stopped.

[0043] During the middle stage of fermentation, after adding alkali, the sampling detection results are compared as shown in the following table:

[0044]

[0045] The comparison of the fermentation process can be referred to Figures 6 to 8As shown in:

[0046] Comparing the above results, it can be seen that under the same fermentation conditions, supplementing the lye in the form of spraying can greatly reduce the impact on the bacteria, which is beneficial to improving the survival rate of viable bacteria, shortening the fermentation time, increasing the yield of the fermentation target product, improving the economic benefits of fermentation, and reducing the fermentation cost.

[0047] In the present invention, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A fermentation system with adjustable pH, characterized in that: It includes a fermentation tank, an alkali solution delivery system and a temporary storage tank for storing alkali solution. The alkali solution delivery system includes an atomizing spray device, a liquid delivery pipe and a liquid supply pump. The atomizing spray device is installed above the fermentation liquid level in the fermentation tank. The atomizing spray device is connected to the temporary storage tank through the liquid delivery pipe. The liquid supply pump is arranged on the liquid delivery pipe.

2. A pH-adjustable fermentation system according to claim 1, characterized in that: The fermentation tank is provided with a stirring device for stirring the fermented liquid. The stirring device comprises a vertically arranged stirring shaft, and the stirring shaft is provided with stirring blades.

3. A pH-adjustable fermentation system according to claim 2, characterized in that: The atomizing spray device comprises an annular tube, which is coaxially sleeved outside the stirring shaft, the diameter of the annular tube is larger than the diameter of the circumscribed circle where the stirring blades are located, atomizing nozzles are evenly arranged on the annular tube, and the annular tube is connected to the liquid delivery pipe.

4. A pH-adjustable fermentation system according to claim 3, characterized in that: The annular tube is provided with a notch, and the atomizing nozzle is arranged from one end of the notch of the annular tube to the other end.

5. A pH-adjustable fermentation system according to claim 3 or 4, characterized in that: The atomizing nozzle is a rotating nozzle.

6. A pH-adjustable fermentation system according to claim 5, characterized in that: The rotating nozzle is an automatic rotating nozzle.

7. A pH-adjustable fermentation system according to claim 6, characterized in that: The automatic rotating spray head includes a connecting head, a rotating head and an atomizing nozzle. One end of the connecting head is connected to the liquid delivery pipe, and the other end of the connecting head is rotatably connected to the rotating head. The atomizing nozzle is circumferentially arranged on the rotating head. The atomizing nozzle utilizes the reaction force of the sprayed liquid to drive the rotating head to rotate.

8. A pH-adjustable fermentation system according to claim 3 or 4, characterized in that: The height of the annular tube is adjustable.

9. The pH-adjustable fermentation system according to claim 1, characterized in that: The liquid supply pump is a screw pump.

10. The pH-adjustable fermentation system according to claim 1, characterized in that: The fermentation tank is provided with a pH detector, and a flow regulating valve is provided between the liquid delivery pipe and the temporary storage tank.

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