Microbial agent fermentation culture device

Abstract

The invention relates to the technical field of microbial fermentation equipment, in particular to a microbial agent fermentation culture device which comprises a fermentation tank, a mixing mechanism and a regulation and control mechanism are arranged in the fermentation tank, and a control system is arranged outside the fermentation tank; a motor is mounted at the top end of the fermentation tank, the mixing mechanism comprises a stirrer rotationally connected in the fermentation tank, an air inlet channel is formed in a shaft where the stirrer is located, a centrifugal impeller is mounted on the stirrer, and the centrifugal impeller is close to the cavity bottom of the fermentation tank; the regulation and control mechanism comprises a detection unit and a compensation assembly which are mounted on the fermentation tank, a gas supply device in the compensation assembly is automatically triggered, the supplementation amount of aerobic gas is increased, a control system automatically triggers a solvent tank in the compensation assembly, the supplementation amount of acid or alkali is automatically adjusted to the fermentation tank, and then the fermentation tank is started. The automatic balance adjustment of the acid-base culture conditions of the liquid culture medium is completed.

Description

Technical Field

[0001] This invention relates to the field of microbial fermentation equipment technology, and in particular to a microbial agent fermentation and cultivation device. Background Technology

[0002] Microbial fermentation is a process that utilizes the life activities of microorganisms to transform organic matter into useful products. These fermentation agents are applied in medical environments, such as in analytical instruments for microbial detection, screening systems in disease diagnosis, cultivation of recurrent pathogens, and medical diagnosis. Furthermore, as a class of biological agents composed of specific microbial species and their metabolites, microbial fermentation agents demonstrate multifaceted application potential in the medical field. They exert their effects through the specific functions and metabolites of microorganisms, providing new ideas and methods for disease treatment and health management.

[0003] The equipment used to prepare microbial agents is usually a fermenter. Traditional fermenters often have the following drawbacks: conventional agitators and stirring methods can easily create dead zones in the tank, resulting in uneven distribution of nutrients (liquid culture medium), dissolved oxygen, and metabolites. When aerobic gas is introduced, it tends to aggregate into large bubbles, resulting in low diffusion efficiency. The effectiveness of microbial agents is closely related to the pH value of the environment. Different types of microorganisms have significantly different pH tolerance ranges, and the pH performance during the cultivation process of nutrients (base liquid, fermentation broth, liquid culture medium) cannot be automatically regulated. Summary of the Invention

[0004] To address the above problems, the present invention provides a microbial agent fermentation and cultivation device, including a fermenter, wherein the fermenter is provided with a mixing mechanism and a control mechanism inside the fermenter, and a control system is provided outside the fermenter. The top of the fermentation tank is equipped with a motor, and the mixing mechanism includes a stirrer that is transferred into the fermentation tank. An air inlet channel is provided on the shaft where the stirrer is located, and a centrifugal impeller is installed on the stirrer. The centrifugal impeller is close to the bottom of the fermentation tank. The control mechanism includes a detection unit and a compensation component installed on the fermenter; The control system is configured to: control the compensation component to add a culture medium to the liquid culture medium in the fermenter; control the compensation component to introduce gas into the liquid culture medium through the air inlet channel; and control the motor to drive the stirrer to adjust the rotation speed; so that the culture medium and gas are dispersed and dissolved in the liquid culture medium under the rotation of the centrifugal impeller.

[0005] As a further preferred embodiment, the detection unit includes a dissolved oxygen detection sensor installed on the fermenter, and the compensation component includes an adapter and a dissolved oxygen input pipe. The adapter is connected to the bottom end of the shaft where the stirrer is located and communicates with the air inlet channel, and the dissolved oxygen input pipe is connected to the other end of the adapter.

[0006] As a further preferred embodiment, the end of the dissolved oxygen input pipe away from the adapter extends outside the fermenter and is connected to a sterile air filtration device.

[0007] As a further preferred embodiment, the detection unit further includes a pH detection sensor installed on the fermenter, and the compensation assembly further includes an acid compensation tank and a salinity compensation tank disposed outside the fermenter; a first compensation pipe is connected to the acid compensation tank, and the other end of the first compensation pipe is connected to the inside of the fermenter; a second compensation pipe is connected to the salinity compensation tank, and the other end of the second compensation pipe is connected to the inside of the fermenter; and liquid pumps are installed on the first compensation pipe and the second compensation pipe.

[0008] As a further preferred embodiment, the first compensation pipe and the second compensation pipe extend horizontally to one end of the fermenter and are symmetrically arranged on both sides of the stirrer, and each has a number of second air holes corresponding to the centrifugal impeller. As a further preferred embodiment, at least one ring of first air holes is formed on the shaft where the agitator is located. The first air holes are perpendicular to the axis and communicate with the air inlet channel, with their outer ends corresponding to the top of the centrifugal impeller.

[0009] As a further preferred embodiment, the fermenter is provided with a jacket around its perimeter, and a heater is provided inside the jacket.

[0010] As a further preferred embodiment, the cavity wall of the fermenter is made of 316L stainless steel, and its cavity wall is polished to a roughness of less than or equal to 0.4 micrometers. Its cavity bottom adopts a conical design, and a discharge pipe is installed at the bottom, with a valve installed on the discharge pipe.

[0011] The advantages of this invention compared to the prior art are: 1. The air inlet channel is set on the stirring shaft of the agitator with the axis of the fermentation tank as the center, and a centrifugal impeller is set at the bottom of the shaft. In addition to the impeller blades mixing the liquid culture medium to accelerate fermentation, the centrifugal impeller will also create a negative pressure zone near the axis by rotating at high speed. The high speed of rotation will draw in the liquid culture medium from the bottom of the tank and then eject it upwards at high speed along the liquid culture medium, so that the liquid culture medium will generate a strong internal circulation in the zone. The aerobic gas is discharged into the zone through the air inlet channel at the axis, which forms a shear with the internally circulating liquid culture medium. It dissolves into the liquid culture medium at the rotation radius of the centrifugal impeller, which has a wider mixing range, reduces reaction dead zones, and improves cultivation efficiency. 2. The centrifugal impeller and the shaft containing the agitator are integrated into a design, and combined with microbubble generation technology, the mass transfer efficiency of oxygen molecules to the base liquid is further improved, and energy consumption is reduced. It is especially suitable for the industrial expansion of high-aerobic bacteria, and the dissolved oxygen efficiency is improved.

[0012] 3. A control system, detection unit, and control mechanism are set up. The key parameters of the fermentation broth collected by the detection unit are transmitted to the control module, triggering the control mechanism to compensate for the base liquid. For example, when the dissolved oxygen detection sensor detects that the dissolved oxygen is below the threshold: First, the motor is triggered to increase the speed, which enhances the stirring and shearing force between the centrifugal impeller and the aerobic gas entering at the shaft, thereby improving the bubble breaking efficiency and stirring speed; Second, the gas supply equipment in the compensation component is automatically triggered to increase the amount of aerobic gas added. The control system will automatically trigger the solvent tank in the compensation component to automatically adjust the amount of acid or alkali added to the fermenter, thereby completing the automatic balance adjustment of the acid-base cultivation conditions of the liquid culture medium. Attached Figure Description

[0013] Figure 1 A three-dimensional schematic diagram of a microbial agent fermentation and cultivation device provided for an embodiment of the present invention; Figure 2 A microbial agent fermentation culture device provided for embodiments of the present invention comprises... Figure 1 A schematic diagram showing the cutaway view; Figure 3 A microbial agent fermentation culture device provided for embodiments of the present invention comprises... Figure 2 Enlarged schematic diagram of part A; Figure 4 A microbial agent fermentation culture device provided for embodiments of the present invention comprises... Figure 2 The resulting planar schematic diagram; Figure 5 A microbial agent fermentation culture device provided for embodiments of the present invention comprises... Figure 2 A schematic diagram showing the air intake channel from a three-dimensional perspective, with the stirring shaft partially cut open. Figure 6 A flowchart illustrating the control system of a microbial inoculant fermentation and cultivation device provided for an embodiment of the present invention.

[0014] In the diagram: 11. Fermentation tank; 111. Jacket; 112. Heater; 12. Mixing mechanism; 121. Stirrer; 122. Air inlet channel; 123. Centrifugal impeller; 124. First vent; 13. Control mechanism; 131. Adapter; 132. Dissolved oxygen input pipe; 133. Acidity compensation tank; 134. Alkalinity compensation tank; 135. Dissolved oxygen sensor; 136. pH sensor; 1331. First compensation pipe; 1341. Second compensation pipe; 1342. Liquid pump; 1343. Second vent; 14. Control system. Detailed Implementation

[0015] The above and other embodiments and advantages of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0016] Throughout the specification and claims, the following terms will have at least the meaning explicitly associated herein, unless the context otherwise requires. The meanings defined below are not intended to limit the terms, but are merely illustrative examples.

[0017] In the description of this invention, the phrase "in one embodiment" does not necessarily refer to the same embodiment, although it may refer to the same embodiment. Similarly, the phrase "in some embodiments," as used herein, does not necessarily refer to the same embodiment when used multiple times, although it may refer to the same embodiment. As used herein, the term "or" is an inclusive "or" operator and is equivalent to the term "and / or," unless the context clearly specifies otherwise. The term "based on" is not exclusive and allows for reliance on additional factors not described, unless the context clearly specifies otherwise. The word "exemplary" herein means "used as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments. The scope of this invention is limited only by the scope of the appended claims, and any examples set forth in this specification are not intended to be limiting, but merely illustrate some of the many possible embodiments of the claimed invention. The various embodiments provided in this invention should not be construed as limiting the scope of protection of this invention.

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0020] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] In one implementation, such as Figures 1-6 As shown: This embodiment provides a microbial agent fermentation and cultivation device, including a fermenter 11. The fermenter 11 is provided with a mixing mechanism 12 and a control mechanism 13 inside, and a control system 14 is provided outside the fermenter 11. A motor is installed at the top of the fermentation tank 11. The mixing mechanism 12 includes an agitator 121 that is transferred into the fermentation tank 11. An air inlet channel 122 is provided on the shaft of the agitator 121. A centrifugal impeller 123 is installed on the agitator 121 and is close to the bottom of the fermentation tank 11. The shaft (mixing shaft) of the agitator 121 is connected to the fermentation tank 11 at a reasonable position through a bearing or bearing bracket to improve the stability of the agitator 121 when rotating (existing assembly technology, not shown in the figure).

[0022] The control mechanism 13 includes a detection unit and a compensation component installed on the fermenter 11; The control system is configured to: control the compensation component to add culture medium to the liquid culture medium in the fermenter 11; control the compensation component to introduce gas into the liquid culture medium through the air inlet channel 122; and control the motor to drive the stirrer 121 to adjust the speed; so that the culture medium and gas are dispersed and dissolved in the liquid culture medium (or fermentation broth, base liquid in this invention) under the rotation of the centrifugal impeller 123.

[0023] In this embodiment, the air inlet channel 122 is located on the shaft of the stirrer 121. Simply put, the air inlet channel 122 is positioned on the stirring shaft. When aerobic gas is injected into the fermenter 11 through the air inlet channel 122, it is equivalent to the aerobic gas entering the fermenter 11 from its core. When the stirrer 121 rotates with the centrifugal impeller 123, in addition to using the impeller blades to mix the liquid culture medium and accelerate fermentation, the centrifugal impeller 123 creates a negative pressure zone near its shaft center due to its high-speed rotation. This high-speed rotation draws in the liquid culture medium from the bottom of the tank and then ejects it upwards at high speed, creating a strong internal circulation of the liquid culture medium in this zone. Simultaneously, the aerobic gas is discharged through the air inlet channel 122 at the shaft center. Within this zone, the liquid culture medium circulating within the centrifuge impeller 123 undergoes shearing action, and the micron-sized bubbles formed by the shearing action of the impeller 123 and the violent collision with the liquid dissolve rapidly into the liquid culture medium (the aerobic gas is efficiently dispersed directly at the centrifuge impeller 123). Therefore, in addition to the aerobic gas rapidly entering the fermenter 11 through the axis, it dissolves in the liquid culture medium precisely at the rotation radius of the centrifuge impeller 123, resulting in a wider mixing range, reduced reaction dead zones, and improved cultivation efficiency. Furthermore, the integrated design of the centrifuge impeller 123 and the air inlet channel 122, combined with microbubble generation technology, further improves the mass transfer efficiency of oxygen molecules to the base liquid, reduces energy consumption, and is particularly suitable for the industrial expansion cultivation of high-aerobic bacteria (such as Bacillus and acetic acid bacteria), where dissolved oxygen efficiency is improved.

[0024] In this embodiment, such as Figure 6As shown, the control mechanism 13 consists of a detection unit and a compensation component forming a real-time response network. For example, the detection unit integrates a pH sensor and a dissolved oxygen detection sensor. The probes of both extend into the liquid culture medium in the fermenter 11. According to the control program programmed by the controller module, the key parameters of the fermentation broth are collected every 5 seconds and transmitted to the control controller module. The fermentation process expert database built into the module compares the real-time data with the preset process curve (such as dissolved oxygen setpoint and pH value) through machine learning algorithms. For example, when the dissolved oxygen detection sensor detects that the dissolved oxygen is below the threshold: firstly, the motor is triggered to increase its speed, thereby enhancing the stirring and shearing force between the centrifugal impeller 123 and the aerobic gas entering at the shaft, improving the bubble breaking efficiency and stirring speed; secondly, the gas supply device in the compensation component is automatically triggered to increase the amount of aerobic gas supplied, thereby increasing the number of oxygen molecules supplied; at the same time, when the pH sensor detects an acid-base imbalance (for example, the pH range of yeast / mold is 5.0-6.0, and when it is below this value), the control system 14 will automatically trigger the solvent tank in the compensation component to automatically adjust the amount of acid or alkali supplied to the fermenter 11, thereby completing the automatic balance adjustment of the acid-base cultivation conditions of the liquid culture medium.

[0025] Furthermore, during the aforementioned dynamic adjustments, the speed of the agitator 121 is controlled by adjusting the speed of the motor. For example, when the above-mentioned index values ​​are in a high range, the agitator 121 rotates at a low speed due to the low compensation injection amount of aerobic and catalyst; conversely, the agitator 121 rotates at a high speed. This matching mode of controlling the speed of the agitator 121 saves energy, reduces shear force damage to the centrifugal impeller 123, and improves its service life.

[0026] like Figure 4 , Figure 5 As shown, the detection unit includes a dissolved oxygen sensor 135 installed on the fermenter 11. The compensation assembly includes an adapter 131 and a dissolved oxygen input pipe 132. The adapter 131 is connected to the bottom end of the shaft where the stirrer 121 is located and communicates with the air inlet channel 122. The dissolved oxygen input pipe 132 is connected to the other end of the adapter 131. The end of the dissolved oxygen input pipe 132 away from the adapter 131 extends outside the fermenter 11 and is connected to a sterile air filtration device.

[0027] like Figure 2 , Figure 3As shown, the dissolved oxygen input pipe 132 is rigidly connected to the bottom of the stirring shaft via an adapter 131, allowing the gas filtered by sterile air to be directly injected into the air intake channel 122. The adapter 131 ensures that the rotation of the stirrer 121 is not affected by the presence of the dissolved oxygen input pipe 132. When the dissolved oxygen detection sensor 135 detects that the dissolved oxygen in the fermenter 11 is lower than the threshold set by the module in the controller, the control system 14 will control the sterile air filtration equipment to compensate for oxygenation. At this time, the gas passes through the dissolved oxygen input pipe 132 to the adapter 131, from the adapter 131 to the air intake channel 122, and from the inner end of the air intake channel 122 to the shearing range of the centrifugal impeller 123. The centrifugal impeller 123 shears the gas into microbubbles, instantly improving the oxygen mass transfer efficiency.

[0028] like Figure 1 , Figure 5 As shown, the detection unit also includes a pH detection sensor 136 installed on the fermenter 11, and the compensation assembly includes an acid compensation tank 133 and a saline compensation tank 134 disposed outside the fermenter 11; the acid compensation tank 133 is connected to a first compensation pipe 1331, the other end of the first compensation pipe 1331 is connected to the inside of the fermenter 11, the saline compensation tank 134 is connected to a second compensation pipe 1341, the other end of the second compensation pipe 1341 is connected to the inside of the fermenter 11, and a liquid pump 1342 is installed on the first compensation pipe 1331 and the second compensation pipe 1341; the ends of the first compensation pipe 1331 and the second compensation pipe 1341 that are connected to the inside of the fermenter 11 extend horizontally and are symmetrically arranged on both sides of the stirrer 121, and each has a number of second air holes 1343 corresponding to the centrifugal impeller 123.

[0029] A pH sensor 136 monitors the acidity or alkalinity of the fermentation broth. When the pH deviates from the set value, the control system 14 activates a compensation mechanism. For example, when acidity imbalance requires compensation: the controller controls the liquid pump 1342 to draw acidic liquid (such as HCl solution) from the acidity compensation tank 133 and spray it above the centrifugal impeller 123 through the first compensation pipe 1331. Similarly, when alkalinity imbalance requires compensation: alkaline liquid (such as NaOH solution) from the alkalinity compensation tank 134 is symmetrically injected above the centrifugal impeller 123 through the second compensation pipe 1341. The compensation liquid is atomized and sprayed out through the second vent 1343, landing in the turbulent zone above the centrifugal impeller 123, where it is sheared by the impeller and rapidly dispersed into the fermentation broth. The symmetrical arrangement of the first compensation pipe 1331 and the second compensation pipe 1341 covers the cross-section of the fermentation broth as the centrifugal impeller 123 rotates, accelerating the pH adjustment speed of the fermentation broth. The compensation solution is sprayed into the fermenter 11 through the second vent 1343, avoiding the cell enrichment area at the bottom of the tank, and is quickly dispersed into the fermentation liquid by the centrifugal impeller 123 to prevent local pH accumulation.

[0030] like Figures 3 to 5As shown, at least one ring of first air holes 124 is formed on the stirring shaft where the stirrer 121 is located. The first air holes 124 are perpendicular to the axis and communicate with the air inlet channel 122, with their outer ends corresponding to the top of the centrifugal impeller 123. The first air holes 124 are formed on the stirring shaft and vertically penetrate the air inlet channel 122. After the gas is horizontally ejected through the first air holes 124, it forms an umbrella-shaped air curtain above the centrifugal impeller 123. The second air hole 1343 is located at the end of the compensation pipe, which supplements the injected gas to the negative pressure area of ​​the centrifugal impeller 123. When the impeller rotates, the airflow from the first air hole 124 is radially thrown out by centrifugal force, and the airflow from the second air hole 1343 is drawn into the center of the impeller by negative pressure. The two airflows form a vortex ring convection.

[0031] like Figure 4 As shown, the fermenter 11 is surrounded by a jacket 111, and a heater 112 is installed inside the jacket 111. The fermenter 11 is equipped with a temperature control function on the outside, and the heating effect of the heater 112 assists in the efficient reaction of the fermentation broth.

[0032] The chamber wall of fermenter 11 is made of 316L stainless steel and is polished to a roughness of less than or equal to 0.4 micrometers. The chamber bottom has a conical design and a discharge pipe with a valve installed at the bottom. The chamber wall is made of 316L stainless steel with a super mirror polish to eliminate micropore dead zones; the conical bottom ensures that 100% of the bacteria / culture medium is collected in the discharge pipe, leaving no residue.

[0033] The above orientation references do not represent the specific orientations of each component in this implementation scheme. This implementation scheme is only for the convenience of describing the scheme and to make relative descriptions based on the orientations of the references. In reality, the specific orientations of each component are based on their actual installation and use, as well as the orientation descriptions that are customary to those skilled in the art. This is hereby stated.

[0034] The specific embodiments described above further illustrate the inventive purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, or improvements made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A microbial inoculant fermentation and cultivation device, characterized in that, Include: The inside of the fermenter (11) is provided with a mixing mechanism (12) and a regulating mechanism (13), and the outside of the fermenter (11) is provided with a control system (14); The top end of the fermenter (11) is provided with a motor, the mixing mechanism (12) comprises a stirrer (121) connected in the fermenter (11), the shaft of the stirrer (121) is provided with an air inlet channel (122), the stirrer (121) is provided with a centrifugal impeller (123), and the centrifugal impeller (123) is close to the bottom of the cavity of the fermenter (11); The regulating mechanism (13) comprises a detection unit and a compensation assembly installed on the fermenter (11); The control system is configured to: control the compensation assembly to add a culture agent into the liquid medium in the fermenter (11); control the compensation assembly to introduce gas into the liquid medium through the air inlet channel (122); and control the motor to drive the stirrer (121) to adjust the rotating speed; so that the culture agent and the gas are dispersed and dissolved in the liquid medium under the rotating action of the centrifugal impeller (123).

2. The microbial inoculant fermentation culture device of claim 1, wherein, The detection unit comprises a dissolved oxygen detection sensor (135) installed on the fermenter (11), the compensation assembly comprises an adapter (131) and a dissolved oxygen input pipe (132), the adapter (131) is connected to the bottom end of the shaft of the stirrer (121) and communicates with the air inlet channel (122), and the dissolved oxygen input pipe (132) is connected to the other end of the adapter (131).

3. The microbial inoculant fermentation culture device of claim 2, wherein, The end of the dissolved oxygen input pipe (132) away from the adapter (131) penetrates out of the fermenter (11) and is connected to a sterile air filtration device.

4. The microbial inoculant fermentation culture device of claim 3, wherein, The detection unit further comprises a PH detection sensor (136) installed on the fermenter (11), and the compensation assembly further comprises an acidic compensation tank (133) and an alkaline compensation tank (134) arranged outside the fermenter (11); the acidic compensation tank (133) is connected with a first compensation pipe (1331), one end of the first compensation pipe (1331) communicates with the fermenter (11), the alkaline compensation tank (134) is connected with a second compensation pipe (1341), one end of the second compensation pipe (1341) communicates with the fermenter (11), and a liquid pump (1342) is installed on the first compensation pipe (1331) and the second compensation pipe (1341).

5. The microbial inoculant fermentation culture device of claim 4, wherein, The ends of the first compensation pipe (1331) and the second compensation pipe (1341) extending horizontally after communicating with the fermenter (11) are symmetrically arranged on both sides of the stirrer (121) and are provided with a plurality of second air holes (1343) corresponding to the centrifugal impeller (123).

6. The microbial inoculant fermentation culture device of claim 5, wherein, At least one circle of first air holes (124) is arranged on the shaft of the stirrer (121), the first air holes (124) are perpendicular to the axis and communicate with the air inlet channel (122), and the outer ends of the first air holes (124) correspond to the upper side of the centrifugal impeller (123).

7. The microbial inoculant fermentation culture device of claim 6, wherein, The fermenter (11) is provided with a jacket (111) outside, and the jacket (111) is provided with a heater (112) inside.

8. The microbial inoculant fermentation culture device of claim 7, wherein, The cavity wall of the fermenter (11) is made of 316L stainless steel, and the cavity wall is polished to have a roughness less than or equal to 0.4 microns; the cavity bottom is designed in a conical shape, and a discharge pipe is installed at the bottom, and a valve is installed on the discharge pipe.

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