Device for digesting and filtering inorganic acid sample

Abstract

The utility model relates to a sample inorganic acid digestion filtering device, which belongs to the field of filtering equipment and comprises a suction filter, and a digestion solution quantifying cylinder, an upper filter cylinder, a filter membrane, a lower filter cylinder and a digestion solution collecting cylinder which are sequentially connected from top to bottom, an upper net-shaped partition plate is arranged at the bottom end of the upper filter cylinder, a lower net-shaped partition plate is arranged at the top end of the lower filter cylinder, and the filter membrane is clamped and fixed between the upper net-shaped partition plate and the lower net-shaped partition plate; a suction pipe is arranged on the side surface of the lower filter cylinder, and the suction filter is connected with the suction pipe; a vent hole A is formed in the digestion solution quantifying cylinder; the vent hole A is provided with a vent hole plug in a matched manner; according to the utility model, digestion liquid can be filtered in a sealed manner, controllable suction filtration power can be provided for filtration, and the filtration speed is improved while a filter membrane is prevented from being damaged.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of filtering equipment, specifically, relate to a sample inorganic acid digestion filter device. BACKGROUND

[0002] Digestion is through strong acid to dissolve the sample, make the organic matter in the sample into free element, convert various valence elements in the sample into the form easy to analyze, in order to obtain clear and transparent, no precipitate solution for subsequent analysis and detection, but digestion is difficult to guarantee that the sample is completely dissolved, such as soil, organic fertilizer, food additive and organic component in the food matrix complex is difficult to completely decompose, need to remove the precipitate or visible suspended solids by further filtration, at present, effective standard such as soil quality effective state lead and cadmium determination atomic absorption method (GB / T23739), determination of total nickel, total cobalt, total selenium, total vanadium, total antimony and total thallium content in fertilizers by inductively coupled plasma atomic emission spectrometry (GB / T39356), determination of lead in food additives (GB5009.75) of national food safety standard all stipulate that filtration is needed, and before using precision instruments for determination, filtration is needed, generally, filtration device is needed to filter the solution after digestion.

[0003] At present, the filtration of digestion solution is usually realized by using funnel and filter paper to filter the digestion solution, and if the filtration process is used with a suction filtration device, the filter paper is easily perforated, and then the digestion solution is leaked out without effective filtration. In order to avoid the perforation of the filter paper, the current digestion solution filtration is realized by using the gravity of the digestion solution, the natural dripping filtration without pressure difference in the non-suction filtration state. Although this method is not easy to damage the filter paper, the filtration speed is very slow, and when the sample processing amount is large, the filtration demand cannot be met. In addition, digestion usually has volatility, and it is difficult to avoid the volatilization of the sample during filtration in the funnel, which pollutes the laboratory environment and affects the accuracy of the detection results. The digestion solution is usually strong acid, and when the digestion solution is added to the funnel and poured out from the filter bottle, the digestion solution is easily spilled, which causes safety hazards. SUMMARY

[0004] In order to overcome the problems in the background art, the utility model provides a sample inorganic acid digestion filter device, which can seal the filtration of the digestion solution, is not easy to spill during filtration operation, and can provide controllable suction filtration power for filtration, improves the filtration speed while avoiding damage to the filter membrane.

[0005] To achieve the above object, the utility model is realized by the following technical scheme:

[0006] The sample inorganic acid digestion and filtration device includes a vacuum filter and, from top to bottom, a digestion solution metering cylinder, an upper filter cylinder, a filter membrane, a lower filter cylinder, and a digestion solution collection cylinder connected in sequence. The bottom of the upper filter cylinder is provided with a mesh partition, and the top of the lower filter cylinder is provided with a lower mesh partition. The filter membrane is clamped between the mesh partition and the lower mesh partition. A suction tube is provided on the side of the lower filter cylinder, and the vacuum filter is connected to the suction tube. A vent hole A is provided on the digestion solution metering cylinder, and a vent plug is provided for the vent hole A.

[0007] Preferably, the filter includes a piston cylinder and a piston rod; the left end of the piston cylinder is provided with a connecting pipe, which is detachably connected to the suction pipe.

[0008] Preferably, the suction tube is equipped with a valve A.

[0009] Preferably, the piston cylinder is provided with an exhaust pipe at its left end; the exhaust pipe is provided with a valve B.

[0010] Preferably, the piston cylinder is provided with scale lines.

[0011] Preferably, both the upper and lower mesh partitions are plate-like structures with mesh openings in the middle.

[0012] Preferably, the vent A is located on the side wall of the upper filter cartridge.

[0013] Preferably, the digestion solution metering cylinder is provided with graduation lines.

[0014] Preferably, the digestion solution metering cylinder is threaded or snapped into the upper filter cylinder, and the upper filter cylinder and the lower filter cylinder are snapped together; the lower filter cylinder and the digestion solution collection cylinder are threaded or snapped together.

[0015] The beneficial effects of this utility model are:

[0016] This invention enables the filtration of digestion solution under sealed conditions, effectively preventing environmental pollution caused by volatilization and its impact on analytical results. Furthermore, the structure of this invention allows for vacuum filtration under sealed conditions, and the vacuum filter composed of a piston cylinder and a piston rod makes it easier to control the filtration speed, reducing or avoiding perforations in the filter membrane and improving the filtration effect.

[0017] This invention prevents spillage when adding digestion solution to the sample before filtration or removing digestion solution after filtration, thus improving operational safety. Attached Figure Description

[0018] Figure 1 This is an exploded view of this utility model;

[0019] Figure 2 This is a top view of the lower mesh partition of this utility model;

[0020] In the diagram, 1-digestion solution metering cylinder, 2-upper filter cylinder, 3-filter membrane, 4-lower filter cylinder, 5-digestion solution collection cylinder, 6-mesh partition, 7-lower mesh partition, 8-suction pipe, 9-vent hole A, 10-piston cylinder, 11-piston rod, 12-connecting pipe, 13-mesh, 14-exhaust pipe, 15-valve B. Detailed Implementation

[0021] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, so as to facilitate the understanding of those skilled in the art.

[0022] In the description of this utility model, unless otherwise stated, the terms "upper", "lower", "left", "right", etc., indicate the orientation or state relationship based on the orientation or state relationship shown in the drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0023] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "equipped with" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] like Figures 1-2 As shown, the sample inorganic acid digestion and filtration device includes a vacuum filter and, from top to bottom, a digestion solution metering cylinder 1, an upper filter cylinder 2, a filter membrane 3, a lower filter cylinder 4, and a digestion solution collection cylinder 5 connected in sequence. The digestion solution metering cylinder 1 is threadedly connected to the upper filter cylinder 2, and the upper filter cylinder 2 and the lower filter cylinder 4 are snap-fitted together; the lower filter cylinder 4 and the digestion solution collection cylinder 5 are threadedly connected. Both the upper filter cylinder 2 and the lower filter cylinder 4 are variable-diameter cylindrical structures (as shown in the attached diagram). Figure 1 The thicker sections of the upper filter cylinder 1 and the lower filter cylinder 2 are respectively provided with internal threads, while the digestion solution metering cylinder 1 and the digestion solution collecting cylinder 5 are respectively provided with external threads. The inner diameter of the lower filter cylinder 4 is slightly larger than the outer diameter of the upper filter cylinder 2, and the upper filter cylinder 2 is inserted into the lower filter cylinder 4 for a sealable connection (or the inner diameter of the upper filter cylinder 2 is slightly larger than the outer diameter of the lower filter cylinder 4, and the lower filter cylinder 4 is inserted into the upper filter cylinder 2). As a preferred embodiment, acid-resistant sealing gaskets can be provided at the connection surfaces between the digestion solution metering cylinder 1 and the upper filter cylinder 2, the upper filter cylinder 2 and the lower filter cylinder 4, and the lower filter cylinder 4 and the digestion solution collecting cylinder 5 to prevent leakage at the sealing surfaces.

[0025] The upper filter cartridge 2 has a mesh partition 6 at its bottom and a lower mesh partition 7 at its top. After the upper filter cartridge 2 and the lower filter cartridge 4 are connected, the filter membrane 3 is clamped between the mesh partition 6 and the lower mesh partition 7. By clamping the filter membrane 3 with the mesh partition 6 and the lower mesh partition 7, the filter membrane 3 is strengthened and supported, effectively preventing or reducing the deformation caused by the gravity or suction force of the digestion liquid on the filter membrane 3, preventing or reducing the probability of filter membrane 3 breakage, and thus reducing or avoiding perforation caused by filter membrane 3 breakage, ensuring the filtration effect. The mesh partition 6 and the lower mesh partition 7 are plate-shaped structures with mesh holes 13 in the middle, which provide channels for the filtrate.

[0026] The suction effect of this utility model is accomplished by a suction filter, which needs to be connected to the lower structure of the filter membrane 3: a suction pipe 8 is provided on the side of the lower filter cylinder 4, the suction filter is connected to the suction pipe 8, and the suction pipe 8 is located below the lower mesh partition 7. Through the suction of the suction filter, a negative pressure is generated below the filter membrane 3, which increases the filtration speed of the digestion solution.

[0027] Because air must enter above the filter membrane 3 to ensure the formation of negative pressure for suction, and the digestion solution metering cylinder 1 is sealed after being connected to the upper filter cylinder 2, a vent hole A9 needs to be opened on the component above the filter membrane 3. There are two ways to open the vent hole A9: Method 1: Open the vent hole A9 on the digestion solution metering cylinder 1. When not filtration is performed, the vent hole A9 is plugged with a vent plug to prevent digestion solution leakage. When suction is performed, the vent plug is removed. Method 2: The vent hole A9 is opened on the side wall of the upper filter cylinder 2, and the opening position is higher than the mesh partition 6. Both methods are acceptable, but experimental verification shows that with Method 2, a small amount of digestion solution is unavoidable from leaking out of the vent hole A9 at the moment the vent plug is opened. However, Method 2 does not affect the structure of the digestion solution metering cylinder 1 and is more convenient for replacing different digestion solution metering cylinders 1. If method one is adopted, all digestion liquid metering cylinders 1 need to have vent holes A9 and be fitted with vent plugs. Therefore, considering convenience and minimizing equipment modifications, method two is preferred. When using method two, the vacuum filter is operated first to create negative pressure under the filter membrane 3 before opening the vent plug (blocking the vent hole with a plug is a conventional structure, and the vent plug is not shown in the attached figure), which can effectively avoid or reduce leakage from the vent hole A9.

[0028] The suction filter of this utility model includes a piston cylinder 10 and a piston rod 11, and a syringe can be directly purchased and used as a suction filter. The left end of the piston cylinder 10 is provided with a connecting tube 12, which is detachably and sealingly connected to the suction tube 8.

[0029] As a preferred embodiment, the suction pipe 8 is equipped with a valve A. When suction is not being performed, the valve A is closed. When the connecting pipe 12 is connected to the suction pipe 8 and suction begins, the valve A is opened.

[0030] As a preferred embodiment, the left end of the piston cylinder 10 is provided with an exhaust pipe 14; the exhaust pipe 14 is equipped with a valve B15. When the volume of digestate to be filtered is large, one piston stroke is insufficient to complete the suction. In this case, valve A can be closed, valve B15 opened, and the piston rod 11 moved to the left to expel the gas inside the piston cylinder 10. Then, valve B15 can be closed and valve A opened to continue suction. It should be noted that this utility model can basically meet the current digestate detection volume requirements without the exhaust pipe 14. The addition of the exhaust pipe 14 is merely an optimized improvement to address situations where the volume of digestate to be filtered is large.

[0031] As a preferred option, the digestion solution metering cylinder 1 is equipped with graduation lines to allow for quantitative measurement of the digestion solution.

[0032] As a preferred option, the piston cylinder 10 is equipped with scale lines, which can be used to control the suction speed and avoid excessive suction force that could damage the filter membrane.

[0033] Demonstration of the use of this utility model:

[0034] (1) After the sample is digested, transfer the digested sample solution to the digested solution metering cylinder 1 and use a dropper or other sampling tool to quantify the sample by referring to the scale line of the digested solution metering cylinder 1; (2) Connect the upper filter cylinder 2 and the lower filter cylinder 4. When connecting, make the filter membrane 3 clamped between the mesh partition 6 and the lower mesh partition 7; (3) Connect the digested solution collection cylinder 5 to the lower filter cylinder 3; (4) Connect the upper filter cylinder 2 to the digested solution metering cylinder 1 and invert it after connecting; (5) Start filtering; after filtering, remove the digested solution collection cylinder 5.

[0035] With proper operation, the structure of this invention prevents spillage when adding the digestion solution sample to the digestion solution metering cylinder 1 before filtration or when removing the digestion solution sample after filtration, effectively avoiding strong acid burns and ensuring high operational safety.

[0036] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of this utility model.

Claims

1. A sample inorganic acid digestion and filtration device, characterized in that: The device includes a vacuum filter and, from top to bottom, a digestion solution metering cylinder, an upper filter cylinder, a filter membrane, a lower filter cylinder, and a digestion solution collection cylinder connected in sequence. The lower filter cylinder has a mesh partition at its bottom and a lower mesh partition at its top. The filter membrane is sandwiched between the mesh partition and the lower mesh partition. A suction pipe is provided on the side of the lower filter cylinder, and the vacuum filter is connected to the suction pipe. A vent hole A is provided on the digestion solution metering cylinder, and a vent plug is fitted to vent hole A.

2. The sample inorganic acid digestion and filtration device according to claim 1, characterized in that: The filter includes a piston cylinder and a piston rod; the left end of the piston cylinder is provided with a connecting pipe, which is detachably connected to the suction pipe.

3. The sample inorganic acid digestion and filtration device according to claim 2, characterized in that: Valve A is installed on the suction tube.

4. The sample inorganic acid digestion and filtration device according to claim 2, characterized in that: The piston cylinder is provided with an exhaust pipe at its left end; valve B is provided on the exhaust pipe.

5. The sample inorganic acid digestion and filtration device according to claim 2, characterized in that: The piston cylinder is provided with scale lines.

6. The sample inorganic acid digestion and filtration apparatus according to any one of claims 1 to 5, characterized in that: Both the upper and lower mesh partitions are plate-like structures with mesh openings in the middle.

7. The sample inorganic acid digestion and filtration device according to claim 1, characterized in that: The vent A is located on the side wall of the upper filter cartridge.

8. The sample inorganic acid digestion and filtration device according to claim 1, characterized in that: The digestion solution metering cylinder is equipped with graduation lines.

9. The sample inorganic acid digestion and filtration device according to claim 1, characterized in that: The digestion solution metering cylinder is threaded or snapped into the upper filter cylinder, and the upper filter cylinder and the lower filter cylinder are snapped together; the lower filter cylinder and the digestion solution collection cylinder are threaded or snapped together.

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