Liquid sampling device for itaconic acid fermentation process

Abstract

The invention discloses a liquid sampling device for itaconic acid fermentation process, which comprises a sampling tube and an operating rod movably inserted in the sampling tube, a suspension liquid sampling unit is slidably arranged on the sampling tube, and a bottom layer liquid sampling unit is detachably mounted at the lower end of the operating rod; according to the device, upper-layer suspension liquid sampling of fermentation liquid can be completed through the suspension liquid sampling unit, bottom-layer fermentation liquid sampling can be completed through the bottom-layer liquid sampling unit, extraction of two samples can be completed through one-time operation, and sampling is more efficient.

Description

Technical Field

[0001] The invention relates to a liquid sampling device for an itaconic acid fermentation process. Background Art

[0002] Itaconic acid is scientifically known as methylene succinic acid and methylene succinic acid. It is an unsaturated dibasic organic acid. It contains unsaturated double bonds and has active chemical properties. It can polymerize itself and other monomers such as acrylonitrile. It is soluble in water, ethanol and other solvents. It can undergo various addition reactions, esterification reactions and polymerization reactions. It is an important raw material for the chemical synthesis industry and an important raw material for chemical production.

[0003] Fermentation is an important step in the preparation of itaconic acid. During the fermentation process, regular sampling and testing are required according to the fermentation cycle to ensure the effectiveness of the fermentation.

[0004] The conventional sampling method is to directly sample by inserting a sampling tube into the fermentation tank. In this sampling method, a large amount of upper suspension first enters the sampling tube during the insertion process, and the sample obtained is not representative enough.

[0005] In order to obtain the most accurate fermentation data, it is necessary to sample the upper suspension and bottom liquid of the fermentation liquid separately and then conduct testing.

[0006] However, the existing sampling equipment obviously cannot meet the requirements of simultaneous needs, and when the number of fermentation tanks is large, the samples are easily mixed up.

[0007] Based on the above problems, we designed a liquid sampling device for itaconic acid fermentation process which can extract the suspension and bottom liquid at the same time. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a liquid sampling device for itaconic acid fermentation process which can extract suspension and bottom liquid at the same time.

[0009] To solve the above problems, the present invention adopts the following technical solutions:

[0010] A liquid sampling device for itaconic acid fermentation process comprises a sampling tube and an operating rod movably inserted into the sampling tube, a suspension sampling unit is slidably arranged on the sampling tube, and a bottom liquid sampling unit is detachably installed at the lower end of the operating rod.

[0011] Preferably, a tube cover is detachably installed on the upper end of the sampling tube, and the upper end of the operating rod passes upward through the tube cover. A limit ring is installed on the rod body of the operating rod, and the limit ring limits the upward movement of the operating rod. A threaded portion is processed on the upper part of the operating rod, and a rod cap is cooperated with the threaded portion, and the rod cap limits the downward movement of the operating rod.

[0012] Preferably, a groove is processed on the upper part of the operating rod, and a scale is arranged in the groove.

[0013] Preferably, the suspension sampling unit includes a first limiting ring and a sampling box, the first limiting ring forms a limit for the upward movement of the sampling box, an elastic clamp ring is embedded in the inner wall of the first limiting ring, the elastic clamp ring is interference fit with the sampling tube, a hollow buoyancy bin is formed by injection molding inside the sampling box, a convex ring is formed by injection molding on the top of the sampling box, a nut is clamped by the convex ring, a sampling bin is formed by injection molding at the lower part of the buoyancy bin inside the sampling box, a sampling hole is opened on the inner wall of the sampling box at a position corresponding to the upper part of the sampling bin, the sampling hole is connected to the sampling bin, an inner tube body is provided at the axis of the sampling box, and a nut is clamped on the outer wall of the inner tube body A sealing ring, wherein the inner tube body closes the sampling hole after sliding down along the sampling box, an external threaded portion is provided on the upper portion of the inner tube, and the diameter of the external threaded portion is larger than the inner diameter of the sampling box. After the inner tube body slides down, the nut cooperates with the external threaded portion, at which time the height of the inner tube body is locked, and the sealing ring seals the sampling hole, a sliding cap is cooperated with the external threaded portion, and the sliding cap transitionally cooperates with the sampling tube, a convex ring is provided at the outer bottom position of the sampling tube, and the convex ring forms a limit for the downward movement of the sliding cap, the inner diameter of the inner tube body is larger than the diameter of the convex ring, and after the connection between the external threaded portion and the sliding cap is released, the sampling box is taken out downward along the sampling tube.

[0014] Preferably, an annular groove is formed by injection molding on the inner wall of the convex ring, and a clamping ring inserted into the groove is formed by injection molding on the outer wall of the nut, and the clamping ring rotates along the groove.

[0015] Preferably, more than three slide grooves are arranged in an annular manner on the inner wall of the sampling box, and an arc-shaped elastic sheet is arranged at the lower part of the inner tube body. The lower end of the elastic sheet is stuck in the slide groove and can slide vertically along the slide groove. When the external threaded part cooperates with the nut, the elastic sheet bulges after being compressed, and the bulged elastic sheet forms a support for the bottom liquid sampling unit; a convex tube part is injection-molded at the bottom of the sampling box, and with the support of the convex tube part, the lower end of the bottom liquid sampling unit is separated from the ground.

[0016] Preferably, the bottom liquid sampling unit comprises a liquid storage cup and a connecting cap, the upper end of the liquid storage cup is processed with an embedding end, the embedding end is inserted into the sampling tube, a liquid storage tank is arranged inside the liquid storage cup, the upper end of the liquid storage tank is processed with an internal thread, a connecting part is arranged at the bottom of the connecting cap, the outside of the connecting part is processed with an external thread matching the internal thread, a liquid inlet hole is processed at a position near the top of the outer wall of the connecting part, a sealing gasket is matched at the outer wall of the connecting part, when the connecting part moves along the lower end of the internal thread When rotated to the limit, the sealing gasket is clamped between the liquid storage cup and the connecting cap. At this time, the liquid inlet hole is closed. The top of the connecting cap is processed with a threaded hole that matches the operating rod. A first sealing gasket is clamped on the outer wall of the embedded end. As the operating rod moves upward, the first sealing gasket is sealed between the sampling tube and the liquid storage cup. The diameter of the liquid storage cup is smaller than the inner diameter of the inner tube body. The liquid storage cup is conical, and its diameter gradually decreases downward. After the liquid storage cup is removed, it is positioned by an elastic sheet.

[0017] Preferably, a sealing ring is provided on the outer wall of the connecting cap, and the sealing ring is interference fit with the inner wall of the sampling tube.

[0018] Preferably, an annular slot is coaxially arranged at the bottom of the connecting cap, a clamping ring made of elastic rubber material is clamped in the slot, an annular filter is clamped on the inner side of the clamping ring, the outer wall of the clamping ring is formed by interference fit with the inner wall of the sampling tube, and the upper end of the embedded end is processed with a small diameter portion, and the small diameter portion fits the inner wall of the filter.

[0019] The beneficial effects of the present invention are:

[0020] Advantage 1: This device can complete the sampling of the upper suspension of the fermentation liquid through the suspension sampling unit, and can complete the sampling of the bottom fermentation liquid through the bottom liquid sampling unit. The extraction of two samples can be completed in one operation, and the sampling is more efficient.

[0021] Advantage 2: After sampling, the bottom liquid sampling unit can be inserted into the suspension sampling unit, so that samples in the same fermentation tank can be placed together to avoid confusion.

[0022] Advantage three, when the device is sampling, before reaching the sampling depth, the bottom liquid sampling unit is in a closed state. Only when the sampling depth is reached will the bottom liquid sampling unit extend from the sampling tube, thereby making the sample more accurate.

[0023] Advantage four: the suspension sampling unit is suspended above the fermentation liquid, thus preventing the device from falling into the fermentation tank.

[0024] Advantage 5: The device has a simple structure, low cost and is suitable for promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a structural schematic diagram of the present invention;

[0027] Figure 2 is a cross-sectional view of the present invention;

[0028] Figure 3 It is an exploded schematic diagram of the operating rod and the bottom liquid sampling unit;

[0029] Figure 4 for Figure 3 A magnified view at point A;

[0030] Figure 5 is a stereogram of the sampling tube;

[0031] Figure 6 It is a schematic diagram of the coordination between the suspension sampling unit and the sampling tube;

[0032] Figure 7 A perspective view of a suspension sampling unit;

[0033] Figure 8 for Figure 6 Enlarged view at B;

[0034] Fig. 9 for Figure 6 Enlarged view at C;

[0035] Fig.10 It is a schematic diagram of the coordination of the suspension sampling unit and the bottom liquid sampling unit;

[0036] Fig.11 It is a cross-sectional view of the bottom liquid sampling unit;

[0037] Fig.12 This is a schematic diagram of the structural explosion of the bottom liquid sampling unit;

[0038] Fig.13 for Fig.11 Enlarged view at D. DETAILED DESCRIPTION

[0039] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0040] Any feature disclosed in this specification (including any additional claims, abstract and drawings), unless otherwise stated, may be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0041] In the description of the present invention, it is necessary to understand that the terms "one end", "the other end", "outside", "upper", "inside", "horizontal", "coaxial", "center", "end", "length", "outer end" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0042] In addition, in the description of the present invention, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0043] In the present invention, unless otherwise clearly specified and limited, the terms "disposed", "socketed", "connected", "through", "plugged" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] See also Figure 1 A liquid sampling device for an itaconic acid fermentation process is shown, comprising a sampling tube 1, and an operating rod 2 movably inserted into the sampling tube 1, a suspension sampling unit 3 is slidably arranged on the sampling tube 1, and a bottom liquid sampling unit 4 is detachably installed at the lower end of the operating rod 2.

[0045] In the above technical solution, the sampling work can be completed simultaneously in one sampling process by the suspension sampling unit 3 and the bottom liquid sampling unit 4, thereby improving the sampling efficiency.

[0046] For multiple fermentation tanks, multiple sets of suspension sampling units 3 and bottom liquid sampling units 4 may be prepared.

[0047] The suspension sampling unit 3 and bottom layer sampling unit 4 of each group can be combined to facilitate classification and avoid mistakes.

[0048] See also Figures 2 to 5As shown, a tube cover 101 is detachably installed on the upper end of the sampling tube 1, and the upper end of the operating rod 2 passes through the tube cover 101 upward. A limit ring 21 is installed on the rod body of the operating rod 2, and the limit ring 21 limits the upward movement of the operating rod 2. A threaded portion 22 is processed on the upper part of the operating rod 2, and a rod cap 23 is matched with the threaded portion 22, and the rod cap 23 limits the downward movement of the operating rod 2.

[0049] In the above technical solution, when the rod cap 23 is screwed down along the threaded portion 22 to the limit position, the sliding of the operating rod 2 is limited by the limiting ring 21 and the rod cap 23 .

[0050] At this time, the operating rod 2 moves upward to the limit position, and the bottom liquid sampling unit 4 cooperates with the sampling tube 2 to form a seal.

[0051] See also Figure 4 As shown, a groove 24 is processed on the upper part of the operating rod 2, and a scale 2444 is arranged in the groove 24.

[0052] The groove 24 and the scale 2444 facilitate marking the position of the rod cap 23.

[0053] See also Figures 5 to 11As shown, the suspension sampling unit 3 includes a first limiting ring 31 and a sampling box 32, the first limiting ring 31 forms a limit for the upward movement of the sampling box 32, an elastic clamp ring 3112 is embedded in the inner wall of the first limiting ring 31, and the elastic clamp ring 3112 is interference fit with the sampling tube 1, a hollow buoyancy chamber 33 is formed by injection molding inside the sampling box 32, a convex ring 34 is formed by injection molding on the top of the sampling box 32, a nut 35 is clamped by the convex ring 34, a sampling chamber 36 is formed by injection molding at the lower part of the buoyancy chamber 33 inside the sampling box 32, a sampling hole 361 is opened on the inner wall of the sampling box 32 at a position corresponding to the upper part of the sampling chamber 36, the sampling hole 361 is connected to the sampling chamber 36, an inner tube body 37 is arranged at the axis of the sampling box 32, and a sealing ring 38 is clamped on the outer wall of the inner tube body 37 1, the inner tube body 37 slides down along the sampling box 32 and closes the sampling hole 361. The upper part of the inner tube 37 is provided with an external threaded portion 371, and the diameter of the external threaded portion 371 is larger than the inner diameter of the sampling box 32. After the inner tube body 37 slides down, the nut 35 cooperates with the external threaded portion 371. At this time, the height of the inner tube body 37 is locked, and the sealing ring 381 seals the sampling hole 361. The external threaded portion 371 is matched with a sliding cap 39, and the sliding cap 39 is transitionally matched with the sampling tube 1. A convex ring 121 is provided at the outer bottom position of the sampling tube 1. The convex ring 121 forms a limit for the downward movement of the sliding cap 39. The inner diameter of the inner tube body 37 is larger than the diameter of the convex ring 121. After the connection between the external threaded portion 371 and the sliding cap 39 is released, the sampling box 32 is taken out downward along the sampling tube 1.

[0054] In the above technical solution, the upper suspension enters the fermentation liquid through the sampling hole 361. When sampling, the sampling tube 1 is pressed downward, so that the first limiting ring 31 pushes the sampling box 32 to sink, so that the upper suspension enters the sampling chamber 36 through the sampling hole 361.

[0055] While sampling the upper layer, the handle bar 2 is moved downward to allow the bottom layer liquid sampling unit 4 below to separate downward from the sampling tube 2, thereby completing the sampling of the bottom fermentation liquid simultaneously.

[0056] After the sampling is completed, the sampling box 32 can be directly taken out downward along the sampling tube 1 by unscrewing the sliding cap 39 .

[0057] When it is necessary to take out the bottom liquid sampling unit 4 , the rod cap 23 needs to be screwed up so that the operating rod 2 has enough distance to slide downwards, so as to take out the bottom liquid sampling unit 4 .

[0058] The nut 35 can lock the inner tube body 37 so that the sealing ring 381 can always effectively seal the sampling hole 361 .

[0059] See also Figure 8 As shown, an annular groove 341 is formed by injection molding on the inner wall of the convex ring 34 , and a clamping ring 351 that is clamped into the groove 341 is formed by injection molding on the outer wall of the nut 35 . The clamping ring 351 rotates along the groove 341 .

[0060] The above technical solution mainly realizes the positioning of the nut 35 .

[0061] See also Figure 6 , Fig. 9 and Fig.10 As shown, more than three slide grooves 3221 are annularly arranged on the inner wall of the sampling box 32, and an arc-shaped elastic sheet 3222 is arranged at the lower part of the inner tube body 37. The lower end of the elastic sheet 3222 is stuck in the slide groove 3221 and can slide vertically along the slide groove 3221. When the external threaded part 371 cooperates with the nut 35, the elastic sheet 3222 bulges after being compressed, and the bulged elastic sheet 3222 forms a support for the bottom liquid sampling unit 4; a convex tube part 3223 is injection-molded at the bottom of the sampling box 32, and with the support of the convex tube part 3223, the lower end of the bottom liquid sampling unit 4 is separated from the ground.

[0062] In the above technical solution, the cooperation between the slide groove 3221 and the elastic sheet 3222 can realize the positioning of the inner tube body 37 and avoid the rotation of the inner tube body 37, so as to better cooperate with the nut and the screw nut.

[0063] After the nut locks the inner tube body 37 , the elastic sheet 3222 is squeezed and elastically deformed, so as to better position the bottom liquid sampling unit 4 .

[0064] See also Figures 10 to 13As shown, the bottom liquid sampling unit 4 includes a liquid storage cup 401 and a connecting cap 402. The upper end of the liquid storage cup 401 is processed with an embedded end 4441, and the embedded end 4441 is inserted into the sampling tube 1. The interior of the liquid storage cup 401 is provided with a liquid storage tank 403, and the upper end of the liquid storage tank 403 is processed with an internal thread 441. The bottom of the connecting cap 402 is provided with a connecting portion 404, and the outside of the connecting portion 404 is processed with an external thread 442 that matches the internal thread 441. A liquid inlet hole 405 is processed near the top position of the outer wall of the connecting portion 404, and a sealing gasket 406 is matched at the outer wall of the connecting portion 404. When the connecting portion 404 is moved along the inner When the thread 441 is screwed down to the limit, the sealing gasket 406 is clamped between the liquid storage cup 401 and the connecting cap 402. At this time, the liquid inlet hole 405 is closed. The top of the connecting cap 402 is processed with a threaded hole 407 that matches the operating rod 2. A first sealing gasket 4442 is clamped on the outer wall of the embedded end 4441. As the operating rod 2 moves upward, the first sealing gasket 4442 is sealed between the sampling tube 1 and the liquid storage cup 401. The diameter of the liquid storage cup 401 is smaller than the inner diameter of the inner tube body 37. The liquid storage cup 401 is conical, and its diameter gradually decreases downward. After the liquid storage cup 401 is removed, it is positioned by the elastic sheet 3222.

[0065] In the above technical solution, sampling can be completed by the cooperation of the liquid storage cup 401 and the connecting cap 402. When sampling, the liquid inlet hole 405 is exposed to the outside of the liquid storage tank 403. When the operating rod 2 is pushed down to expose the liquid inlet hole 405 to the outside of the sampling tube 1, the fermented bottom liquid enters the liquid storage tank 403 through the liquid inlet hole 405, completing the sampling work.

[0066] The provision of the sealing gasket 406 can prevent the fermentation liquid from entering the sampling tube 1 when the sampling tube 1 does not reach the required depth.

[0067] See also Fig.11 As shown, a sealing ring 4222 is clamped on the outer wall of the connecting cap 402 , and the sealing ring 4222 is interference fit with the inner wall of the sampling tube 1 .

[0068] During the sampling process, the rod cap 23 limits the downward movement of the operating rod 2, so that during the sampling process, the sealing ring 4222 is always sealed between the connecting cap 402 and the sampling tube 1 to prevent a large amount of fermentation liquid from entering the interior of the sampling tube 1.

[0069] See also Fig.11 , Fig.12 and Fig.13As shown, an annular slot 4223 is coaxially arranged at the bottom of the connecting cap 402, and a clamping ring 4224 made of elastic rubber material is clamped in the slot 4223. An annular filter 4225 is clamped on the inner side of the clamping ring 4224. The outer wall of the clamping ring 4224 is formed by interference fit with the inner wall of the sampling tube 1, and the upper end of the embedded end 4441 is processed with a small diameter portion 4443, and the small diameter portion 4443 fits the inner wall of the filter 4225.

[0070] According to the above technical solution, after the connecting cap 402 is removed upward, the filter 4225 can be directly pulled out downward, which is convenient for maintenance of the filter 4225, and the filter 4225 can slide down along the small path portion 4443. Therefore, after the sampling is completed, there is no need to remove the filter 4225, and the connecting cap 402 can be screwed down to complete the closure of the liquid storage tank 403.

[0071] The particles in the fermentation tank are deposited in the lower layer of the fermentation liquid. Therefore, the filter 4225 can block these particles, so that the device can effectively extract the fermentation liquid and avoid extracting a large amount of particles.

[0072] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A liquid sampling device for itaconic acid fermentation process, characterized in that: The invention comprises a sampling tube (1) and an operating rod (2) movably inserted into the sampling tube (1); a suspension sampling unit (3) is slidably arranged on the sampling tube (1); and a bottom liquid sampling unit (4) is detachably mounted at the lower end of the operating rod (2).

2. The liquid sampling device for itaconic acid fermentation process according to claim 1, characterized in that: The upper end of the sampling tube (1) is detachably mounted with a tube cover (101); the upper end of the operating rod (2) passes through the tube cover (101) upwards; a limit ring (21) is mounted on the rod body of the operating rod (2); the limit ring (21) limits the upward movement of the operating rod (2); a threaded portion (22) is processed on the upper part of the operating rod (2); a rod cap (23) is matched with the threaded portion (22); the rod cap (23) limits the downward movement of the operating rod (2).

3. The liquid sampling device for itaconic acid fermentation process according to claim 2, characterized in that: A groove (24) is processed on the upper part of the operating rod (2), and a scale (2444) is arranged in the groove (24).

4. The liquid sampling device for itaconic acid fermentation process according to claim 1, characterized in that: The suspension sampling unit (3) comprises a first limiting ring (31) and a sampling box (32), wherein the first limiting ring (31) limits the upward movement of the sampling box (32), an elastic collar (3112) is embedded in the inner wall of the first limiting ring (31), and the elastic collar (3112) is interference fit with the sampling tube (1), a hollow buoyancy chamber (33) is formed by injection molding inside the sampling box (32), and a convex ring (34) is formed by injection molding on the top of the sampling box (32), The convex ring (34) is clamped with a nut (35); a sampling chamber (36) is formed by injection molding at the lower part of the buoyancy chamber (33) inside the sampling box (32); a sampling hole (361) is opened on the inner wall of the sampling box (32) at a position corresponding to the upper part of the sampling chamber (36); the sampling hole (361) is connected to the sampling chamber (36); an inner tube body (37) is arranged at the axis of the sampling box (32); a sealing ring (381) is clamped on the outer wall of the inner tube body (37) The inner tube body (37) slides down along the sampling box (32) and closes the sampling hole (361). The upper part of the inner tube (37) is provided with an external threaded portion (371). The diameter of the external threaded portion (371) is larger than the inner diameter of the sampling box (32). After the inner tube body (37) slides down, the nut (35) cooperates with the external threaded portion (371). At this time, the height of the inner tube body (37) is locked, and the sealing ring (381) seals the sampling hole (361). The threaded portion (371) is matched with a sliding cap (39), and the sliding cap (39) is transitionally matched with the sampling tube (1). A convex ring (121) is provided at the outer bottom position of the sampling tube (1), and the convex ring (121) forms a limit for the downward movement of the sliding cap (39). The inner diameter of the inner tube body (37) is larger than the diameter of the convex ring (121). After the connection between the external threaded portion (371) and the sliding cap (39) is released, the sampling box (32) is taken out downward along the sampling tube (1).

5. The liquid sampling device for itaconic acid fermentation process according to claim 4, characterized in that: An annular clamping groove (341) is formed by injection molding on the inner wall of the convex ring (34), and a clamping ring (351) clamped in the clamping groove (341) is formed by injection molding on the outer wall of the nut (35), and the clamping ring (351) rotates along the clamping groove (341).

6. The liquid sampling device for itaconic acid fermentation process according to claim 4, characterized in that: More than three slide grooves (3221) are arranged in an annular shape on the inner wall of the sampling box (32), and an arc-shaped elastic sheet (3222) is arranged at the lower part of the inner tube body (37). The lower end of the elastic sheet (3222) is stuck in the slide groove (3221) and can slide vertically along the slide groove (3221). When the external threaded portion (371) cooperates with the nut (35), the elastic sheet (3222) bulges after being compressed, and the bulged elastic sheet (3222) forms a support for the bottom liquid sampling unit (4); a convex tube portion (3223) is formed by injection molding at the bottom of the sampling box (32), and under the support of the convex tube portion (3223), the lower end of the bottom liquid sampling unit (4) is separated from the ground.

7. The liquid sampling device for itaconic acid fermentation process according to claim 7, characterized in that: The bottom liquid sampling unit (4) comprises a liquid storage cup (401) and a connecting cap (402). The upper end of the liquid storage cup (401) is processed with an embedding end (4441), and the embedding end (4441) is inserted into the sampling tube (1). The interior of the liquid storage cup (401) is provided with a liquid storage tank (403), and the upper end of the liquid storage tank (403) is processed with an internal thread (441). The bottom of the connecting cap (402) is provided with a connecting portion (404), and the outside of the connecting portion (404) is processed with an external thread (442) matching the internal thread (441). A liquid inlet hole (405) is processed near the top of the outer wall of the connecting portion (404), and a sealing gasket (406) is matched on the outer wall of the connecting portion (404). When the connecting portion (404) is connected along the inner thread (441), the connecting portion (404) is provided with a sealing gasket (406). When the thread (441) is screwed down to the limit, the sealing gasket (406) is clamped between the liquid storage cup (401) and the connecting cap (402). At this time, the liquid inlet hole (405) is closed. The top of the connecting cap (402) is processed with a threaded hole (407) that matches the operating rod (2). A first sealing gasket (4442) is clamped on the outer wall of the embedded end (4441). As the operating rod (2) moves upward, the first sealing gasket (4442) is sealed between the sampling tube (1) and the liquid storage cup (401). The diameter of the liquid storage cup (401) is smaller than the inner diameter of the inner tube body (37); the liquid storage cup (401) is conical, and its diameter gradually decreases downward. After the liquid storage cup (401) is removed, it is positioned by the elastic sheet (3222).

8. The liquid sampling device for itaconic acid fermentation process according to claim 7, characterized in that: A sealing ring (4222) is clamped on the outer wall of the connecting cap (402), and the sealing ring (4222) is interference fit with the inner wall of the sampling tube (1).

9. The liquid sampling device for itaconic acid fermentation process according to claim 7, characterized in that: An annular slot (4223) is coaxially arranged at the bottom of the connecting cap (402), and a clamping ring (4224) made of elastic rubber material is clamped in the slot (4223). An annular filter (4225) is clamped on the inner side of the clamping ring (4224). The outer wall of the clamping ring (4224) is formed by interference fit with the inner wall of the sampling tube (1). The upper end of the embedded end (4441) is processed with a small diameter portion (4443), and the small diameter portion (4443) fits the inner wall of the filter (4225).

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