A hexavalent chromium sample sampling device with multi-stage filtering function

Abstract

This invention provides a hexavalent chromium sample sampling device with multi-stage filtration function, belonging to the field of hexavalent chromium preparation technology. It includes a primary filtration component, a secondary filtration component, and a tertiary filtration device. This application adds a primary and secondary filtration component for multiple filtrations of the filtrate after the reaction, separating impurities from the reaction solution. This reduces the working pressure of the front-end filtration component, extends its service life, and achieves high filtration efficiency. The addition of a side strip assembly with a filter membrane connected to the third housing enables the purification and separation of the generated hexavalent chromium. The filtered solution can be further transported for processing, leaving the generated hexavalent chromium on the filter membrane surface for easy sampling and transfer. This provides high filtration efficiency and ensures the purity of the generated hexavalent chromium, enabling multi-stage filtration of the reaction solution for hexavalent chromium preparation.

Description

Technical Field

[0001] The utility model belongs to the technical field of hexavalent chromium production, and in particular relates to a hexavalent chromium sample sampling device with a multi-stage filtering function. Background Art

[0002] Hexavalent chromium exists in the form of oxygen-containing acid radicals. Uses in electronic products: Hexavalent chromium is often used as chromic acid in the electrochemical industry. It is also used as a colorant in pigments (lead chromate) and as an anticorrosive agent (sodium dichromate) in cooling water circulation systems, such as heat pumps, industrial freezers, and refrigerator heat exchangers. Uses in the strip galvanizing industry: Hexavalent chromium is used for post-plating passivation of galvanized sheets to increase the corrosion resistance of galvanized sheets.

[0003] Hexavalent chromium belongs to heavy metal ions in a broad sense. When the hexavalent chromium is prepared, the existing hexavalent chromium sample sampling device has a high concentration of the solution after the reaction is completed, and the pressure of the filtration equipment is relatively high. Moreover, when the hexavalent chromium is finally separated, the existing integrated active filtration device leaves hexavalent chromium on the surface of the filter element, blocking the mesh of the filter element of the filtration device, which will reduce the filtration efficiency and affect the solution's continued backward transportation. Utility Model Content

[0004] The utility model aims to provide a hexavalent chromium sample sampling device with a multi-stage filtering function, aiming to solve the problems raised in the above-mentioned background technology.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A hexavalent chromium sample sampling device with multi-stage filtering function, comprising a primary filtering component and a secondary filtering component,

[0007] The primary filter assembly comprises a first housing, a first filter element installed inside the first housing, and a first cover plate installed on the top of the first housing, wherein the first cover plate is located above the first filter element, and the first filter element is clamped on the inner side wall of the lower end of the first cover plate;

[0008] The secondary filter assembly includes a second shell, a second filter element installed inside the second shell, and a second cover plate installed on the top of the second shell. The liquid inlet of the second shell is connected to the liquid outlet of the first shell through a pipeline.

[0009] As a preferred solution of the utility model, the liquid outlet of the second shell is installed with a three-stage filter assembly, and the three-stage filter assembly includes a third shell and a filter membrane installed inside the third shell, and the liquid inlet of the third shell is connected to the liquid outlet of the second shell through a pipeline.

[0010] As a preferred solution of the utility model, the filter membrane side wall is encapsulated with an edge strip, the edge strip is sealed and clamped on the inner side wall of the third shell, and the edge strip side wall is provided with an inclined structure matching the filter membrane.

[0011] As a preferred solution of the utility model, a bracket is installed at the bottom of the third shell, and the first shell and the second shell are fixedly connected to the bracket by bolts in sequence.

[0012] As a preferred solution of the utility model, a material collection box is inserted into the bottom side wall of the third shell, a hopper matching the material collection box is threadedly connected to the middle position of the bottom of the third shell, and the lower end of the hopper extends into the interior of the material collection box.

[0013] As a preferred solution of the utility model, an absorption tube is sealed and plugged into the bottom of the hopper, a base is clamped in the middle of the bottom of the collecting box, and the lower end of the absorption tube is plugged into the inner side of the middle through hole of the base.

[0014] As a preferred solution of the utility model, a spring sheet is inserted into the side wall of the base, and the protrusion at the end of the spring sheet is clamped in the middle of the groove on the bottom side wall of the absorption tube. A hand-position groove structure matching the spring sheet is opened in the middle of the side wall of the base.

[0015] As a preferred solution of the utility model, a spring located below the base is connected to the middle position of the aggregate box by bolts, the upper end of the spring is connected to a support plate by bolts, the base is clamped to the upper end of the support plate, and a bayonet structure matching the buckle of the side wall of the support plate is provided at the bottom of the base.

[0016] As a preferred solution of the utility model, a connecting rod is threadedly connected to the center position of the collecting box, and the upper end of the connecting rod is clamped on the bottom side wall of the supporting plate through a bearing member.

[0017] As a preferred solution of the utility model, a third cover plate is clamped on the upper end of the third shell, and a rubber pad matching the upper end of the third shell is bonded to the side wall of the third cover plate, and a suction connector is threadedly connected to the side wall of the third shell.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] The present application adds a primary filter assembly consisting of a first housing, a first filter element and a first cover plate to perform preliminary filtration on the reaction solution, remove most of the impurities in the reaction solution, and then transport the filtered solution backwards, which is convenient for subsequent processing, reduces the operating pressure of subsequent equipment, and can be maintained separately without affecting the operation of subsequent equipment;

[0020] The present application adds a secondary filter assembly consisting of a second filter element and a second housing for re-filtering the filtrate after the reaction, separating impurities from the reaction solution, and multi-stage filtration, which can reduce the working pressure of the front-end filter assembly and extend the service life of the front-end filter assembly. The combined filter assembly can also be maintained separately, reducing maintenance costs and having high operating filtration efficiency.

[0021] The present application adds a side strip assembly equipped with a filter membrane and connects it to the third shell, so that the generated hexavalent chromium can be purified and separated. The filtered solution can continue to be transported backward for processing, and the generated hexavalent chromium is left on the surface of the filter membrane for convenient sampling and transfer processing. The filtration efficiency is high and the purity of the generated hexavalent chromium can be guaranteed. It is connected with the primary filter assembly and the secondary filter assembly at the front end, and the reaction solution prepared by the hexavalent chromium can be subjected to multi-stage filtration processing;

[0022] The present application increases a collection box and connects it to the bottom of the third shell to close the space at the bottom of the third shell, protects the hopper installed in the middle position of the bottom of the third shell, and facilitates the hopper to collect filtered liquid. The absorption tube connects to the hopper at the bottom of the third shell to form a sealed connection component, which can ensure that the absorption tube for receiving the filtrate and the three-stage filter assembly form a negative pressure during filtration, so that the filtrate can flow into the filtrate absorption tube for easy transfer. The base is used to cooperate in supporting and limiting the absorption tube, maintain the stability of the position of the absorption tube, and keep the absorption tube running safely. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0024] Figure 1 This is one of the overall structural diagrams of the utility model;

[0025] Figure 2 This is the second schematic diagram of the overall structure of the utility model;

[0026] Figure 3 It is a front structural schematic diagram of the utility model;

[0027] Figure 4 It is a top view schematic diagram of the utility model;

[0028] Figure 5 It is a schematic diagram of the cross-sectional structure of the utility model at AA.

[0029] In the figure: 100, primary filter assembly; 101, first shell; 102, first filter element; 103, first cover plate; 200, secondary filter assembly; 201, second shell; 202, second filter element; 203, second cover plate; 300, tertiary filter assembly; 301, third shell; 302, filter membrane; 303, side strip; 304, bracket; 305, collection box; 306, hopper; 307, absorption tube; 308, base; 309, spring; 310, spring; 311, support plate; 312, connecting rod; 313, third cover plate; 314, suction filter joint. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0033] Example 1

[0034] Reference Figure 1-5 , which is the first embodiment of the utility model, and which provides a primary filtering component 100 of a hexavalent chromium sample sampling device with a multi-stage filtering function, comprising

[0035] A first housing 101, a first filter element 102 installed inside the first housing 101, and a first cover plate 103 installed on the top of the first housing 101, wherein the first cover plate 103 is located above the first filter element 102, and the first filter element 102 is clamped on the inner side wall of the lower end of the first cover plate 103;

[0036] When in use, the solution after the reaction is completed enters the interior of the first shell 101 from the liquid inlet of the first shell 10. The first filter element 102 can use a sand core of grade G1 or above. The liquid enters the first filter element 102 to filter out most of the large particle impurities, and then enters the subsequent processing device. When the internal components of the first shell 101 need to be maintained, the first cover plate 103 is opened, and the first cover plate 103 is closed after the maintenance is completed.

[0037] In summary, the present application adds a primary filter assembly 100 composed of a first shell 101, a first filter element 102 and a first cover plate 103 to perform preliminary filtration on the reaction solution, remove most of the impurities in the reaction solution, and then transport the filtered solution backward to facilitate subsequent processing, reduce the operating pressure of subsequent equipment, and can be maintained separately without affecting the operation of subsequent equipment.

[0038] Example 2

[0039] Reference Figure 1-5 , which is the second embodiment of the utility model. Different from the previous embodiment, this embodiment provides a secondary filter assembly 200 of a sampling device, including

[0040] The second housing 201, the second filter element 202 installed inside the second housing 201 and the second cover plate 203 installed on the top of the second housing 201, the liquid inlet of the second housing 201 is connected with the liquid outlet of the first housing 101 through a pipeline.

[0041] Among them, the second filter element 202 is used to further filter the reaction solution, so as to facilitate subsequent equipment to filter and separate the reaction solution and separate the generated hexavalent chromium from the solution. The second filter element 202 can adopt a G2 grade sand core, but because the second filter element 202 needs to filter finer impurity particles, the pressure of the second filter element 202 during operation is higher, and a step edge structure or a matching connecting component can be added to the side wall of the second filter element 202 for limiting and fixing, so as to maintain the stability of the connection structure between the second filter element 202 and the second shell 201.

[0042] During use, when the solution passes through the secondary filter assembly 200, the remaining medium-sized particles of impurities will be filtered out by the second filter element 202, and the impurities will accumulate above the second filter element 202 to cooperate with subsequent cleaning operations. The solution will flow from the bottom of the second shell 201 to the rear equipment.

[0043] In summary, the present application adds a secondary filter component 200 composed of a second filter element 202 and a second shell 201 for re-filtering the filtrate after the reaction to separate impurities from the reaction solution. Multi-stage filtration can reduce the working pressure of the front-end filter component and extend the service life of the front-end filter component. The combined filter component can also be separately maintained, reducing maintenance costs and having high operating filtration efficiency.

[0044] Example 3

[0045] Reference Figure 1-5 , which is the third embodiment of the present utility model. Different from the previous embodiment, this embodiment provides a three-stage filtering component 300 of the sampling device.

[0046] Specifically, the liquid outlet of the second shell 201 is installed with a three-stage filter assembly 300, which includes a third shell 301 and a filter membrane 302 installed inside the third shell 301, and the liquid inlet of the third shell 301 is connected to the liquid outlet of the second shell 201 through a pipeline.

[0047] Among them, a three-stage filtering component 300 consisting of a third shell 301 and a filter membrane 302 is added to further filter the filtrate, leaving the sample on the filter membrane 302, and the filtrate is discharged from the bottom of the third shell 301, which is convenient for transferring the sample.

[0048] Furthermore, the side wall of the filter membrane 302 is encapsulated with a side strip 303 , the side strip 303 is sealed and clamped on the inner wall of the third shell 301 , and the side wall of the side strip 303 is provided with an inclined structure matching the filter membrane 302 .

[0049] Among them, the edge strip 303 is added to fix the filter membrane 302 and connect it with the third shell 301. The edge strip 303 can improve the connection strength between the filter membrane 302 and the third shell 301, prevent the filter membrane 302 from curling up during use, and prevent the filter membrane 302 from being loosened due to excessive force, thereby maintaining the stable use of the filter membrane 302. The edge strip 303 with an inclined structure can guide the filtrate along the inclined surface to the collection component below the third shell 301.

[0050] Preferably, a bracket 304 is installed at the bottom of the third shell 301 , and the first shell 101 and the second shell 201 are fixedly connected to the bracket 304 in sequence by bolts.

[0051] Among them, the bracket 304 installed at the bottom of the third shell 301 is connected to the first shell 101 and the second shell 201 respectively, which can maintain the stability of the position of the first shell 101 and the second shell 201 during operation and reduce the impact of the filtering process on the stability of the first shell 101 and the second shell 201 and the third shell 301.

[0052] When in use, when the filtrate enters the third shell 301, it will pass through the filter membrane 302 component. The reaction solution and some small molecular substances can pass through the filter membrane 302 freely. For large molecular substances, the selective filter membrane 302 is not permeable to them and they are intercepted, thereby completing the purification and separation of the generated hexavalent chromium. The filter membrane 302 is preferably a 0.45um microporous filter membrane.

[0053] In summary, the present application adds a side strip 303 component equipped with a filter membrane 302 and connects it to the third shell 301, so as to purify and separate the generated hexavalent chromium. The filtered solution can continue to be transported backward for processing, and the generated hexavalent chromium is left on the surface of the filter membrane 302 for easy sampling and transfer processing. The filtration efficiency is high and the purity of the generated hexavalent chromium can be guaranteed. It is connected with the primary filter component 100 and the secondary filter component 200 at the front end, and the reaction solution prepared by hexavalent chromium can be subjected to multi-stage filtration processing.

[0054] Example 4

[0055] Reference Figure 1-5 , which is the third embodiment of the present utility model. Different from the previous embodiment, this embodiment provides a suction filtration component of a three-stage filtration component 300.

[0056] Specifically, a material collecting box 305 is inserted into the side wall of the bottom of the third shell 301 , and a hopper 306 matching the material collecting box 305 is threadedly connected to the middle position of the bottom of the third shell 301 , and the lower end of the hopper 306 extends into the interior of the material collecting box 305 .

[0057] The addition of the collecting box 305 connected to the bottom of the third shell 301 can seal the space at the bottom of the third shell 301, protect the hopper 306 installed in the middle of the bottom of the third shell 301, and facilitate the hopper 306 to collect the filtered liquid.

[0058] Furthermore, an absorption tube 307 is sealed and plugged into the bottom of the hopper 306 , a base 308 is clamped in the middle of the bottom of the collecting box 305 , and the lower end of the absorption tube 307 is plugged into the inner side of the middle through hole of the base 308 .

[0059] Among them, the absorption tube 307 is connected to the hopper 306 at the bottom of the third shell 301 to form a sealed connection component, which can ensure that the absorption tube 307 for receiving the filtrate and the three-stage filter assembly 300 form a stable negative pressure during filtration, so that the filtrate can flow into the filtrate absorption tube 307 for easy transfer. The base 308 is used to support and limit the absorption tube 307, maintain the stability of the position of the absorption tube 307, and keep the absorption tube 307 running safely.

[0060] Furthermore, a spring piece 309 is inserted into the side wall of the base 308 , and the protrusion at the end of the spring piece 309 is clamped in the middle of the groove on the bottom side wall of the absorption tube 307 . A hand-positioned groove structure matching the spring piece 309 is opened in the middle of the side wall of the base 308 .

[0061] Among them, adding a spring piece 309 on the side wall of the base 308 to contact the groove on the side wall of the absorption tube 307 can maintain a stable connection between the base 308 and the bottom of the absorption tube 307, so that the base 308 is always stuck on the bottom of the absorption tube 307, supporting and protecting the bottom of the absorption tube 307, preventing the bottom of the absorption tube 307 from colliding with the inside of the collection box 305, and keeping the absorption tube 307 safe to use.

[0062] Preferably, a spring 310 located below the base 308 is bolted to the middle position of the aggregate box 305, the upper end of the spring 310 is bolted to a support plate 311, the base 308 is clamped to the upper end of the support plate 311, and a snap-on structure matching the side wall snap of the support plate 311 is provided at the bottom of the base 308.

[0063] Among them, the spring 310 equipped with a support plate 311 is docked with the base 308, and can support the base 308 on the basis of the connection with the collecting box 305, maintain the base 308 to provide an upward thrust under the elastic force of the spring 310, keep the absorption tube 307 docked with the hopper 306, and can also provide a reverse buffering force to the absorption tube 307 through the base 308 when the absorption tube 307 moves downward, thereby preventing the absorption tube 307 from falling.

[0064] It should be noted that a connecting rod 312 is threadedly connected to the center of the collecting box 305, and the upper end of the connecting rod 312 is clamped on the bottom side wall of the supporting plate 311 through a bearing.

[0065] Among them, a connecting rod 312 is installed in the middle of the aggregate box 305 and connected to the support plate 311. With the cooperation of the bearing, when the connecting rod 312 is rotated, the connecting rod 312 will rotate from the side wall of the aggregate box 305 to adjust the extension length. Since the end of the connecting rod 312 is connected to the support plate 311 through the bearing, the rotation of the connecting rod 312 will pull the support plate 311 to translate inside the aggregate box 305, thereby adjusting the height of the support plate 311, which is used to adjust and maintain the absorption tube 307.

[0066] It should be noted that the third cover plate 313 is clamped on the upper end of the third shell 301, and the side wall of the third cover plate 313 is bonded with a rubber pad matching the upper end of the third shell 301, and the side wall of the third shell 301 is threadedly connected with a filtration connector 314.

[0067] Among them, a third cover plate 313 is installed on the third shell 301 to close the third shell 301, keep the three-stage filter assembly 300 in a stable working space, and reduce the impact of the external environment on the three-stage filter assembly 300. Adding a rubber pad on the inner side of the third cover plate 313 can improve the sealing performance of the connection between the third cover plate 313 and the third shell 301. A suction connector 314 is installed on the side wall of the third shell 301 to connect the suction device. A vacuum pump equipped with filter paper, funnel and other components is used to reduce the pressure in the third shell 301 to achieve the purpose of solid-liquid separation.

[0068] When in use, a vacuum pump equipped with filter paper, funnel and other components is connected to the filtration joint 314. At this time, the internal pressure of the third shell 301 is reduced. Since the absorption tube 307 is connected to the hopper 306 at the bottom of the third shell 301 to form a sealed connection component, the absorption tube 307 for receiving the filtrate and the three-stage filter assembly 300 can form a stable negative pressure suction during filtration, so that the filtrate can flow into the filtrate absorption tube 307 and continue to transfer backward.

[0069] In summary, the present application can close the space at the bottom of the third shell 301 by adding a collection box 305 that is connected to the bottom of the third shell 301, and protect the hopper 306 installed in the middle position of the bottom of the third shell 301, so that the hopper 306 can collect the filtered liquid. The absorption tube 307 is connected to the hopper 306 at the bottom of the third shell 301 to form a sealed connection component. During filtration, it can ensure that the absorption tube 307 for receiving the filtrate and the three-stage filter assembly 300 form a negative pressure, so that the filtrate can flow into the filtrate absorption tube 307 for easy transfer. The base 308 is used to cooperate with the support and limit of the absorption tube 307, maintain the stability of the position of the absorption tube 307, and keep the absorption tube 307 safe.

[0070] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and ratio of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangements, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present utility model. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the present invention is not limited to a specific embodiment, but extends to various modifications that still fall within the scope of the appended claims.

[0071] Additionally, in order to provide a concise description of example embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0072] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0073] It should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A hexavalent chromium sample sampling device with multi-stage filtering function, characterized in that: It comprises a primary filter assembly (100) and a secondary filter assembly (200), The primary filter assembly (100) comprises a first housing (101), a first filter element (102) installed inside the first housing (101), and a first cover plate (103) installed on the top of the first housing (101), wherein the first cover plate (103) is located above the first filter element (102), and the first filter element (102) is clamped on the inner side wall of the lower end of the first cover plate (103); The secondary filter assembly (200) comprises a second shell (201), a second filter element (202) installed inside the second shell (201), and a second cover plate (203) installed on the top of the second shell (201); the liquid inlet of the second shell (201) is connected to the liquid outlet of the first shell (101) through a pipeline.

2. The hexavalent chromium sample sampling device with multi-stage filtering function according to claim 1, characterized in that: The liquid outlet of the second shell (201) is installed with a three-stage filter assembly (300), the three-stage filter assembly (300) comprising a third shell (301) and a filter membrane (302) installed inside the third shell (301), and the liquid inlet of the third shell (301) is connected to the liquid outlet of the second shell (201) through a pipeline.

3. The hexavalent chromium sample sampling device with multi-stage filtering function according to claim 2, characterized in that: The side wall of the filter membrane (302) is encapsulated with a side strip (303), the side strip (303) is sealed and clamped on the inner side wall of the third shell (301), and the side wall of the side strip (303) is provided with an inclined surface structure matching the filter membrane (302).

4. The hexavalent chromium sample sampling device with multi-stage filtering function according to claim 3, characterized in that: A bracket (304) is installed at the bottom of the third shell (301), and the first shell (101) and the second shell (201) are fixedly connected to the bracket (304) in sequence by bolts.

5. The hexavalent chromium sample sampling device with multi-stage filtering function according to claim 4, characterized in that: A material collection box (305) is inserted into the bottom side wall of the third shell (301), and a hopper (306) matching the material collection box (305) is threadedly connected at the middle position of the bottom of the third shell (301), and the lower end of the hopper (306) extends into the interior of the material collection box (305).

6. The hexavalent chromium sample sampling device with multi-stage filtering function according to claim 5, characterized in that: An absorption tube (307) is sealed and plugged into the bottom of the hopper (306), a base (308) is clamped in the middle of the bottom of the collection box (305), and the lower end of the absorption tube (307) is plugged into the inner side of the middle through hole of the base (308).

7. The hexavalent chromium sample sampling device with multi-stage filtering function according to claim 6, characterized in that: The side wall of the base (308) is plugged with an elastic sheet (309), the protrusion at the end of the elastic sheet (309) is clamped in the middle of the groove on the bottom side wall of the absorption tube (307), and a hand position groove structure matching the elastic sheet (309) is provided in the middle of the side wall of the base (308).

8. The hexavalent chromium sample sampling device with multi-stage filtering function according to claim 7, characterized in that: The middle position of the aggregate box (305) is connected to a spring (310) located below the base (308) by bolts, and the upper end of the spring (310) is connected to a support plate (311) by bolts. The base (308) is clamped to the upper end of the support plate (311), and the bottom of the base (308) is provided with a snap-fit ​​structure that matches the side wall buckle of the support plate (311).

9. The hexavalent chromium sample sampling device with multi-stage filtering function according to claim 8, characterized in that: A connecting rod (312) is threadedly connected to the center of the material collecting box (305), and the upper end of the connecting rod (312) is clamped to the bottom side wall of the support plate (311) through a bearing member.

10. The hexavalent chromium sample sampling device with multi-stage filtering function according to claim 9, characterized in that: The upper end of the third shell (301) is clamped with a third cover plate (313), and the side wall of the third cover plate (313) is bonded with a rubber pad matching the upper end of the third shell (301), and the side wall of the third shell (301) is threadedly connected with a suction filter joint (314).

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