Sample pretreatment device for food detection

Abstract

The invention discloses a sample pretreatment device for food detection, relates to the technical field of sample pretreatment, and aims to solve the technical problem of excessive bubbles caused by easy mixing of gas in the pretreatment extraction process, the sample pretreatment device comprises two circular rings, a fixed column is fixed between the two circular rings, one side of each circular ring is connected with a bent extension rod, and one side of each bent extension rod is fixedly provided with a clamping arc. A homogenizing shell is restrained among the inner peripheries of the multiple clamping arcs, a discharging opening is formed in the bottom of the homogenizing shell, a center shaft is arranged in the center of the interior of the homogenizing shell, multiple stirring and cutting tools are arranged on the periphery of the center shaft, and a sealing cover, a metal deformation piece and a check valve nozzle are further arranged in the homogenizing shell. Through shape transformation, efficient improvement can be carried out, the extraction quality is high, the whole process is sealed, external gas is prevented from entering, the interference of the external gas on full contact of a solvent and food tissues is reduced, the possibility that a detection signal is interfered by bubbles is reduced, the detection precision is improved, the instrument blockage risk can be reduced, and the instrument maintenance cost is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sample pretreatment, and more specifically, to a sample pretreatment device for food detection. Background Art

[0002] In the field of food pretreatment and extraction, with the continuous improvement of the requirements for the quality and safety of food extracts, the quality control of extracts has become increasingly crucial. Extraction is not only widely used in food processing, but also plays an important role in the preparation of raw materials for pharmaceuticals, cosmetics, etc.

[0003] In the current pretreatment and extraction process, the problem of excessive bubbles is generally faced. On the one hand, during the crushing and juicing of food, a large amount of air will mix into the material to form bubbles. These bubbles not only reduce the space utilization rate of the extraction equipment, but also hinder the subsequent extraction operation. For example, when using the solvent extraction method to extract the active ingredients in food, the bubbles will prevent the solvent from fully contacting the food tissue, interfere with the solid-liquid mass transfer process, reduce the extraction efficiency, prolong the extraction time, and increase the production cost.

[0004] On the other hand, excessive bubbles have a significant impact on the detection and analysis of extracts. In precision detection links such as spectroscopic analysis and chromatographic analysis, the bubbles will cause abnormal light path scattering or absorption, interfere with the detection signal, reduce the detection accuracy, and in severe cases, cause deviations in the detection results, making it impossible to accurately reflect the true content of each component in the extract. In addition, the bubbles entering the pipelines and detectors of the detection instrument may cause instrument blockage, increase the instrument maintenance cost, and shorten the service life of the instrument.

[0005] Although there are currently some technologies for removing bubbles in liquids, such as the simple static degassing method, this method takes a long time and is difficult to meet the needs of large-scale production; while the vacuum degassing method has high requirements for equipment, high operating costs, and in a vacuum environment, some volatile active ingredients will escape with the gas, reducing the quality of the extract. In view of this, we propose a sample pretreatment device for food detection. Summary of the Invention

[0006] The purpose of the present invention is to provide a sample pretreatment device for food detection to solve the technical problem of easy gas mixing and excessive bubbles in the pretreatment and extraction process.

[0007] To solve the above technical problems, the present invention provides the following technical solution: A sample pretreatment device for food detection, comprising two rings, a fixing column is fixed between the two rings, a bent rod is connected to one side of the ring, a clamping arc is fixed to one side of the bent rod, a homogenizing shell is constrained between the inner circumferences of the plurality of clamping arcs, a discharge port is opened at the bottom of the homogenizing shell, a central shaft is provided at the center inside the homogenizing shell, a plurality of stirring and cutting tools are arranged on the outer circumference of the central shaft, the plurality of stirring and cutting tools are arranged radially, a driving motor is installed at the top of the central shaft, a cavity is opened on the side wall of the homogenizing shell, a convex arc seat is installed at the bottom of the homogenizing shell, the outer circumference of the central shaft is connected to a closing cover through a one-way bearing, a deformation metal sheet in contact with the homogenizing shell is fixed to the bottom of the closing cover, the closing cover is connected to the homogenizing shell, both the homogenizing shell and the deformation metal sheet are made of shape memory polymer material into a spherical structure, the upper half of the homogenizing shell is a structure that is heated and deformed into a cone shape, after the homogenizing shell is heated and deformed, a circulation track is formed inside, the convex arc seat is provided with an inner cavity communicating with the inside of the homogenizing shell and the cavity, and a check valve nozzle is installed inside the inner cavity.

[0008] Preferably, a top plate is provided above the homogenizing shell, the fixing part of the driving motor is connected to the top plate, and a connecting rod is connected between the top plate and the ring.

[0009] Preferably, the stirring and cutting tool includes two side blades, the thickness of the two side blades gradually increases from the side edges to the center, and a plurality of side impact ribs with gradually increasing diameters are installed on the side edges of the two side blades.

[0010] Preferably, the stirring and cutting tool includes a telescopic sleeve, the outer circumference of the telescopic sleeve is fixed to the center of the two side blades, an anti-collision ball is fixed to one end of the telescopic sleeve, an opening is opened at the other end of the telescopic sleeve, a telescopic rod is inserted into the opening end with a limit tenon, the telescopic rod is fixed to the central shaft, and a spring is arranged between the telescopic rod and the telescopic sleeve.

[0011] Preferably, the circulation track includes a top arc surface, the top arc surface is one side surface after the deformation metal sheet is thermally deformed, the top arc surface is a conical structure with a diameter gradually decreasing from top to bottom, a bottom arc surface is provided below the top arc surface on one side of the convex arc seat, the bottom arc surface is a conical structure with a diameter gradually increasing from top to bottom, and a return slope surface is arranged between the top arc surface and the bottom arc surface.

[0012] Preferably, a heating wire is embedded around the curve of the side wall of the homogenizing shell, a positioning needle column is fixed between the cavities, and a plurality of mixing ports communicating with the cavities are opened in the upper half of the homogenizing shell.

[0013] Preferably, the check valve nozzle includes a positioning ring which is fixed to the inner cavity. A waterproof membrane sleeve is adhesively fixed to the inner ring of the positioning ring. The waterproof membrane sleeve is made of neoprene with elasticity and waterproof function. A plurality of water outlet pipes and drain pipes are installed on the waterproof membrane sleeve and are distributed in an annular array.

[0014] Preferably, the water outlet pipes and the drain pipes are respectively fixed to the upper half and the lower half of the waterproof membrane sleeve. Elastic sheets which are connected to the positioning ring and have the ability of elastic deformation are fixed to the outer peripheries of the water outlet pipes and the drain pipes. A plurality of the elastic sheets form a convex and pointed structure.

[0015] Preferably, an inner expansion ring is installed on the inner wall of the water outlet pipe. A plurality of arc-shaped pointed sheets are connected to one side of the drain pipe. The plurality of arc-shaped pointed sheets are in an arc-shaped fan structure and have elasticity. A closed pointed cone is formed after the plurality of arc-shaped pointed sheets are extruded.

[0016] Preferably, an empty opening communicating with the discharge port is formed at the center of the top of the convex arc seat. A liquid discharge port communicating with the empty opening is arranged on the outer side of the convex arc seat. The bottom of the cavity communicates with the discharge port.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present invention seals the inlet through the closing cover to form a fully enclosed environment during the extraction process, effectively preventing external gas from entering, suppressing the generation of bubbles from the source. This not only avoids the reduction of the space utilization rate of the extraction equipment by bubbles, reduces the interference of bubbles on the full contact between the solvent and the food tissue, reduces the possibility of the detection signal being interfered by bubbles, improves the detection accuracy, but also reduces the risk of instrument blockage, greatly reduces the instrument maintenance cost, and solves the problem of excessive bubbles easily mixed in during the pretreatment extraction process.

[0018] 2. The present invention also adopts a high-strength alloy steel central shaft and radially distributed stirring and cutting tools. Driven by a stable drive motor, the stirring and cutting tools generate centrifugal force when cutting food by virtue of the unique design of increasing thickness and side impact ribs, and cooperate with the spiral crushing path to greatly improve the crushing efficiency, crush the food more finely. This increases the specific surface area of the material, creates favorable conditions for the full contact between the extractant and the food components, significantly improves the extraction effect, shortens the extraction time, reduces the production cost, further improves the homogenization effect and reduces the extraction time.

[0019] 3. The homogeneous shell of the present invention is made of a shape memory material such as nickel-titanium alloy, which can be deformed into a pear-shaped structure under the action of a heating wire. In cooperation with the circulation track formed by the convex arc seat and the deformed metal sheet, and the rotational movement driven by the central axis, an efficient internal circulation of the internal substances and liquid is formed. During this process, the substances and liquid flow orderly under the guidance of the top arc surface, bottom arc surface and return slope surface, realizing efficient internal circulation extraction, improving the quality and yield of the extract, and further enhancing the extraction effect and efficiency.

[0020] 4. The present invention also makes the cavity on the side wall of the homogeneous shell, the mixing port and the check valve nozzle cooperate with each other. During the circulation process, a small part of the liquid enters the cavity through the mixing port and then discharges from the inner cavity, forming a convection with the circulating liquid. This not only further strengthens the mass transfer efficiency of substances during the extraction process, makes the reaction between the extractant and food components more sufficient, but also further improves the extraction effect and efficiency.

[0021] 5. The present invention can also accurately control the bidirectional flow of the liquid through the check valve nozzle. When the mixed flow liquid is output from the inner cavity, it will orderly discharge through the drain pipe, multiple arc tip pieces and the water outlet pipe to ensure the smooth outflow of the mixed flow liquid. When a small amount of circulating liquid attempts to enter the inner cavity, the liquid pressure pushes the elastic piece to undergo elastic deformation, causing the water outlet pipe and the drain pipe to approach each other, and multiple arc tip pieces to contact and squeeze the inner expansion ring, forming a closed structure to prevent the liquid from flowing back. When the incoming liquid is blocked and flows back, the elastic piece automatically recovers, enabling the check valve nozzle to resume the mixing function again, ensuring the stable and continuous mixing process and avoiding interference with the extraction process due to liquid backflow. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the present invention; Figure 2 is a schematic internal structure diagram of the homogeneous shell in the homogenization stage of the present invention; Figure 3 is a schematic half-sectional structure diagram of the homogeneous shell in the homogenization stage of the present invention; Figure 4 is a diagram of the radial arrangement state of the cutting and stirring tool of the present invention; Figure 5 is a schematic structural diagram of the cutting and stirring tool of the present invention; Figure 6 is a schematic internal structure diagram of the homogeneous shell in the extraction stage of the present invention; Figure 7 is a schematic half-sectional structure diagram of the homogeneous shell in the extraction stage of the present invention; Figure 8 is a schematic half-sectional structure diagram of the convex arc seat of the present invention; Figure 9 is a schematic half-sectional structure diagram of the check valve nozzle of the present invention; Figure 10This is a schematic diagram of the state of the arc tip piece when the check valve nozzle of the present invention is in a closed state.

[0023] Explanation of the reference numerals in the figure: 1. Ring; 2. Fixed column; 3. Bent rod; 4. Clamping arc; 5. Homogeneous shell; 51. Cavity; 52. Mixed flow port; 6. Central axis; 601. Tenon insertion tube; 602. Tenon insertion rod; 7. Stirring and cutting tool; 8. Convex arc seat; 9. Sealing cover; 10. Deformable metal sheet; 11. Check valve nozzle; 12. Driving motor; 13. Top plate; 14. Connecting rod; 15. Shielding inclined tube; 16. Positioning pin column; 18. Heating wire; 701. Both sides cutting edges; 702. Side impact rib; 703. Telescopic sleeve; 704. Anti-collision ball; 705. Telescopic rod; 901. Top arc surface; 902. Bottom arc surface; 903. Backflow slope surface; 111. Positioning ring; 112. Waterproof membrane sleeve; 113. Water outlet pipe; 114. Drain pipe; 115. Elastic sheet; 116. Inner expansion ring; 117. Arc tip piece. Detailed implementation manners

[0024] As Figures 1 to 10 shown, a sample pretreatment device for food detection according to the present invention constructs a stable framework based on two rings 1. The two rings 1 are connected by fixed columns 2. The fixed columns 2 are precisely designed in terms of quantity, position and size to ensure the relative position stability of the two rings 1, providing reliable support for the entire device. One side of the ring 1 is connected with a bent rod 3. The bent rod 3 is made of high-strength metal material, with good flexibility and strength. Its bent shape design fits the overall spatial layout of the device. One side of the bent rod 3 is fixed with a clamping arc 4. Multiple clamping arcs 4 act together to constrain the homogeneous shell 5 between the inner circumferences. The inner side surface of the clamping arc 4 is closely attached to the outer circumference of the homogeneous shell 5, and an anti-slip design is adopted to prevent the homogeneous shell 5 from displacing or shaking during operation, ensuring the stability of the device operation. A top plate 13 is arranged above the homogeneous shell 5. The top plate 13 is connected with the ring 1 through a connecting rod 14. The connecting rod 14 further enhances the stability of the entire structure and provides reliable support for the top plate 13.

[0025] The bottom of the homogeneous shell 5 is provided with a discharge port to facilitate the discharge of the crushed materials. At the central position inside the homogeneous shell 5, a central shaft 6 is arranged. The central shaft 6 is made of high-strength alloy steel, with good rigidity and fatigue resistance, ensuring that it will not deform or break during high-speed rotation. A plurality of stirring and cutting tools 7 are radially arranged on the outer periphery of the central shaft 6. This radial design enables the stirring and cutting tools 7 to cover a larger working area when rotating, improving the crushing efficiency. A driving motor 12 is installed at the top of the central shaft 6. The fixing part of the driving motor 12 is connected to the top plate 13 by fastening means such as bolts, ensuring the stability of the driving motor 12 during operation and providing stable and strong power for the rotation of the central shaft 6 and the stirring and cutting tools 7.

[0026] The stirring and cutting tool 7 is composed of two side blades 701. The thickness of the two side blades 701 gradually increases from the side edges of the two blades to the center. This unique design enables the stirring and cutting tool 7 not only to cut food during rotation but also to generate centrifugal force during cutting to fling the food outward. A plurality of gradually expanding side impact ribs 702 are installed on the side edges of the two side blades 701. The side impact ribs 702 collide with the food during the process of the food being flung, further crushing the food and centrifugally flinging the food, while increasing the force on the food and strengthening the crushing and extraction effect.

[0027] A closed cover 9 is connected to the outer periphery of the central shaft 6 through a one-way bearing. The closed cover 9 is connected to the homogeneous shell 5. Through the cooperation of the one-way bearing, this connection can be achieved through various methods such as mortise and tenon insertion, interference fit, or threaded connection. Thus, when the central shaft 6 rotates, it can drive the homogeneous shell 5 to rotate.

[0028] To facilitate feeding, the central shaft 6 is composed of a mortise rod 602 and a mortise tube 601 that are mutually limited by mortise and tenon insertion. Through the one-way bearing, the closed cover 9 can be lifted to add materials inside. After the material addition is completed, the connection of the closed cover 9 is completed to prevent air from entering during extraction.

[0029] Working principle: By closing the inlet through the closed cover 9, the interior is in a sealed state during the extraction process, and external gas cannot enter, further avoiding the generation of bubbles and contributing to improving the extraction effect.

[0030] Homogenizing shell 5 Homogenizing shell 5 is installed with convex arc seat 8 at the bottom, and a deformed metal sheet 10 in contact with homogenizing shell 5 is fixed at the bottom of closing cover 9. The deformed metal sheet 10 is in contact with homogenizing shell 5, and the deformed metal sheet 10 is deformed synchronously by heat transfer. The upper half of homogenizing shell 5 is a structure that is deformed into a cone by heat. The side wall curve of homogenizing shell 5 is surrounded and embedded with heating wire 18. The heating wire 18 is connected to an external power supply. The heating temperature of the heating wire 18 corresponds to the deformation temperature of nickel-titanium alloy. This can be achieved by selecting heating materials or temperature controllers of different materials. In order to cooperate with the transformation of its shape, the stirring and cutting tool 7 includes a telescopic sleeve 703, the periphery of the telescopic sleeve 703 is fixed to the center of the blades 701 on both sides, an anti-collision ball 704 is fixed to one end of the telescopic sleeve 703, and the anti-collision ball 704 keeps a certain safety distance between the blades 701 on both sides and the homogenizing shell 5, and the other end of the telescopic sleeve 703 is provided with an opening, and a telescopic rod 705 is inserted into the limit tenon at the open end, and the telescopic rod 705 is fixed to the central axis 6, and a spring is arranged between the telescopic rod 705 and the telescopic sleeve 703, and the telescopic sleeve 703 can be contracted by the elasticity of the spring, and when the shape is changed, the contraction can be adaptively performed without affecting the extraction.

[0031] The homogeneous shell 5 is made of a shape memory material in a spherical structure. The shape memory material is preferably nickel-titanium alloy. Nickel-titanium alloy has a unique shape memory effect. Within a certain temperature range, it can remember its initial shape. When deformed by an external force, it becomes a conical structure. As long as it is heated to a specific temperature above the phase transition temperature, it will quickly return to its original shape.

[0032] When it becomes a conical structure, a circulation track is formed inside the homogenizing shell 5, and the circulation track includes a top arc surface 901, which is a side surface of the deformed metal sheet 10 after thermal deformation. The top arc surface 901 is a conical structure with a diameter that gradually decreases from top to bottom. The top arc surface 901 guides the material and liquid to fall from the side to the center. A bottom arc surface 902 is provided below the top arc surface 901 and is located on one side of the convex arc seat 8. The bottom arc surface 902 is a conical structure with a diameter that gradually increases from top to bottom. A reflux slope 903 is provided between the top arc surface 901 and the bottom arc surface 902. The bottom arc surface 902 guides the material and liquid to move from the center to the reflux slope 903, and can move toward the center by cooperating with the rotation of its slope and the homogenizing shell 5.

[0033] Working principle: Before deformation, the interior of the homogenizing chamber is generally in a spherical shape. In this shape, it has a larger homogenizing area. The structural design of the blades 701 on both sides can homogenize it more efficiently.

[0034] When homogenization is nearly complete, heating the heating wire 18 can deform the homogenization shell 5 into a pear-shaped structure. In combination with the top arc surface 901, the bottom arc surface 902, and the reflux slope surface 903, and combined with the rotation of the homogenization shell 5 driven by the central axis 6, the centrifugal force generated forms a circulation track, enabling efficient internal circulation extraction inside.

[0035] It is worth introducing that the overall process operates in a closed manner, and external gas cannot enter, greatly reducing the generation of bubbles and facilitating subsequent detection.

[0036] To further improve the extraction effect, a cavity 51 is provided on the side wall of the homogenization shell 5. A positioning pin column 16 is fixed on the inner wall of the cavity 51. The positioning pin column 16 is provided in multiple numbers and is evenly distributed, mainly playing a role in supporting the cavity 51 and maintaining the shape stability. Multiple mixing ports 52 communicating with the cavity 51 are provided in the upper half of the homogenization shell 5. The mixing ports 52 can be safely filtered by a filter layer to prevent solid particulate matter from entering. The convex arc seat 8 is provided with an inner cavity communicating with the inside of the homogenization shell 5 and the cavity 51. Working principle: During the circulation process, a small part of the liquid will enter the cavity 51 through the mixing port 52 and then be discharged from the inner cavity. The discharged liquid will then generate convection with the liquid and substances during the circulation process, further enhancing the extraction efficiency.

[0037] To prevent the circulating liquid from entering the inner cavity.

[0038] A check valve nozzle 11 is installed inside the inner cavity.

[0039] The check valve nozzle 11 includes a positioning ring 111. The positioning ring 111 is fixed to the inner cavity. An anti-water membrane sleeve 112 is adhesively fixed to the inner ring of the positioning ring 111. The anti-water membrane sleeve 112 is made of neoprene with elasticity and waterproof function. A plurality of groups of water outlet pipes 113 and drain pipes 114 distributed in an annular array are installed on the anti-water membrane sleeve 112. The water outlet pipes 113 and the drain pipes 114 are respectively fixed to the upper half and the lower half of the anti-water membrane sleeve 112. Elastic sheets 115 connected to the positioning ring 111 and having elastic deformation ability are fixed to the outer periphery of the water outlet pipes 113 and the drain pipes 114. A shielding inclined pipe 15 is provided on one side of the water outlet pipe 113. The outer peripheral arc surface of the shielding inclined pipe 15 faces the liquid flow direction, further preliminarily preventing the liquid during the circulation process from entering the inner cavity. An inner expansion ring 116 is installed on the inner wall of the water outlet pipe 113. A plurality of arc tip pieces 117 are connected to one side of the drain pipe 114. The plurality of arc tip pieces 117 are arc-shaped fan pieces and have elasticity. After being squeezed, the plurality of arc tip pieces 117 form a closed sharp cone.

[0040] Working principle: When the mixed-flow liquid is output from the inner cavity, it will first be discharged through the drain pipe 114, multiple arc tip pieces 117 and the water outlet pipe 113. When a small amount of circulating liquid enters the inner cavity, it will push the elastic piece 115 to deform elastically and move, causing the water outlet pipe 113 and the drain pipe 114 to approach each other. When the multiple arc tip pieces 117 contact the inner expansion ring 116, extrusion will occur, causing it to be closed, thus achieving closure and avoiding backflow and internal filling. Due to the water-impermeable material of the waterproof membrane sleeve 112, when the incoming liquid is blocked and flows back, the elastic piece 115 automatically returns, and the mixed flow can be carried out again.

[0041] Furthermore, multiple elastic pieces 115 form a convex tip structure, which can cause the liquid during backflow to concentrate towards the center and generate a high-speed backflow. This design is beneficial to changing the flow velocity difference between the liquid entering and discharging from the inner cavity, and ensuring the stability of the elastic piece 115 to rebound and recover.

[0042] In order not to affect the discharging of materials, a hollow opening communicating with the discharging port is provided at the center of the top of the convex arc seat 8, and a liquid discharging port communicating with the hollow opening is provided on the outer side of the convex arc seat 8. The bottom of the cavity 51 communicates with the discharging port, thereby avoiding the generation of residual materials.

[0043] In order to facilitate the cleaning of the homogenizing shell 5, its interior can be flushed with high pressure, and then operated in cooperation to make the clear water circulate and clean, thus completing the cleaning.

[0044] The embodiments disclosed in the present invention are preferred embodiments, but not limited thereto. Those of ordinary skill in the art can easily understand the spirit of the present invention based on the above embodiments and make different extensions and changes. However, as long as they do not depart from the spirit of the present invention, they are within the protection scope of the present invention.

Claims

1. A sample pretreatment device for food testing, characterized in that: It comprises two circular rings, a fixed column is fixed between the two circular rings, a bending extension rod is connected to one side of the circular ring, a clamping arc is fixed to one side of the bending extension rod, a homogenizing shell is constrained between the inner peripheries of the multiple clamping arcs, a discharge port is opened at the bottom of the homogenizing shell, a central axis is arranged at the center of the homogenizing shell, a plurality of stirring and cutting knives are arranged on the outer periphery of the central axis, the plurality of stirring and cutting knives are arranged radially, and a driving motor is installed on the top of the central axis; A cavity is provided on the side wall of the homogeneous shell, a convex arc seat is installed on the bottom of the homogeneous shell, a closing cover is connected to the outer periphery of the central axis through a one-way bearing, a deformable metal sheet in contact with the homogeneous shell is fixed to the bottom of the closing cover, the closing cover is connected to the homogeneous shell, the homogeneous shell and the deformable metal sheet are both made of a spherical structure of a shape memory polymer material, the upper half of the homogeneous shell is a structure that is deformed into a cone shape by heat, a circulating track is formed inside the homogeneous shell after being deformed by heat, the convex arc seat is provided with an inner cavity connected to the interior of the homogeneous shell and the cavity, and a check valve mouth is installed inside the inner cavity.

2. A sample pretreatment device for food testing according to claim 1, characterized in that: A top plate is arranged above the homogenizing shell, the driving motor fixing part is connected to the top plate, and a connecting rod is connected between the top plate and the circular ring.

3. A sample pretreatment device for food testing according to claim 1, characterized in that: The mixing and cutting tool comprises blades on both sides, and the blades on both sides have a structure with gradually increasing thickness from the edges to the center, and the edges of the blades on both sides are equipped with a plurality of side impact ribs with gradually expanding diameters.

4. A sample pretreatment device for food testing according to claim 3, characterized in that: The mixing and cutting tool comprises a telescopic sleeve, the outer periphery of which is fixed to the centers of the blades on both sides, an anti-collision ball is fixed to one end of the telescopic sleeve, an opening is opened at the other end of the telescopic sleeve, a telescopic rod is inserted into the limiting tenon at the opening end, the telescopic rod is fixed to the central axis, and a spring is arranged between the telescopic rod and the telescopic sleeve.

5. A sample pretreatment device for food testing according to claim 4, characterized in that: The circulating track includes a top arc surface, which is a side surface of the deformed metal sheet after thermal deformation. The top arc surface is a conical structure with a diameter that gradually decreases from top to bottom. A bottom arc surface is provided below the top arc surface on one side of the convex arc seat. The bottom arc surface is a conical structure with a diameter that gradually increases from top to bottom. A return slope surface is provided between the top arc surface and the bottom arc surface.

6. A sample pretreatment device for food testing according to claim 5, characterized in that: A heating wire is embedded in the side wall of the homogenizing shell in a curved shape, positioning needles are fixed between the cavities, and a plurality of mixing ports communicating with the cavities are opened in the upper half of the homogenizing shell.

7. A sample pretreatment device for food testing according to claim 6, characterized in that: The check valve mouth includes a positioning ring, which is fixed to the inner cavity. A waterproof membrane sleeve is bonded and fixed to the inner ring of the positioning ring. The waterproof membrane sleeve is made of chloroprene rubber with elasticity and waterproof function. Multiple groups of outlet pipes and drain pipes distributed in a circular array are installed on the waterproof membrane sleeve.

8. A sample pretreatment device for food testing according to claim 7, characterized in that: The outlet pipe and the drain pipe are respectively fixed to the upper and lower halves of the waterproof membrane sleeve. Elastic sheets connected to the positioning ring and having elastic deformation capability are fixed to the outer periphery of the outlet pipe and the drain pipe. A plurality of the elastic sheets form a convex structure.

9. A sample pretreatment device for food testing according to claim 8, characterized in that: A shielding inclined pipe is installed on one side of the outlet pipe, an inner expansion ring is installed on the inner wall of the outlet pipe, and a plurality of arc-tip pieces are connected to one side of the drain pipe. The plurality of arc-tip pieces are arc-sector-shaped pieces with elasticity, and a closed pointed cone is formed after being squeezed.

10. A sample pretreatment device for food testing according to any one of claims 1 to 9, characterized in that: An empty opening connected to the discharge port is provided at the center of the top of the convex arc seat, a liquid discharge port connected to the empty opening is provided on the outer side of the convex arc seat, and the bottom of the cavity is connected to the discharge port.

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