Sealed sampling membrane support and VOCs (volatile organic compounds) online monitoring equipment

Abstract

The utility model discloses a sealed type sampling membrane support and VOCs on-line monitoring equipment, belongs to the environmental monitoring technical field, the sealed type sampling membrane support comprises a membrane support block and a membrane pressing block, a membrane tray is arranged between the membrane support block and the membrane pressing block, the membrane tray is cylindrical, the bottom of the membrane tray is of a porous structure, and the membrane pressing block is arranged on the membrane tray. A film pressing ring which is in a closed ring shape after being installed is arranged in the film tray, a limiting protrusion is arranged on the inner side wall of the film tray, and the lower surface of the limiting protrusion is an inclined face. A first cavity is formed between the film supporting block and the film tray, a second cavity is formed between the film tray and the film pressing block, sealing devices are arranged on the contact face of the film supporting block and the film tray and the contact face of the film tray and the film pressing block, an air inlet connector is arranged on the film supporting block, and an air outlet connector is arranged on the film pressing block. And locking devices are arranged on the outer sides of the film supporting block and the film pressing block. The sealed sampling membrane support and the VOCs on-line monitoring equipment disclosed by the utility model are good in sealing performance and accurate in sampling value.

Description

Technical Field

[0001] This utility model relates to the field of environmental monitoring technology, and in particular to a sealed sampling membrane holder and an online VOCs monitoring device. Background Technology

[0002] VOCs (Volatile Organic Compounds) refer to organic compounds with a saturated vapor pressure greater than 70 Pa at room temperature and a boiling point below 260℃ at normal pressure, or all organic compounds with a vapor pressure greater than or equal to 10 Pa at 20℃ that are volatile. VOCs participate in the formation of ozone and secondary aerosols in the atmosphere, and have a significant impact on regional atmospheric ozone pollution and PM2.5 pollution. VOCs are important precursors to urban haze and photochemical smog, mainly originating from processes such as coal chemical industry, petrochemical industry, fuel and coating manufacturing, and solvent manufacturing and use.

[0003] VOCs have a significant impact on environmental safety and harm human health, therefore, it is necessary to detect and treat VOCs generated in industrial activities and daily life. Existing VOCs online monitoring equipment can collect and analyze gases, outputting VOCs analysis results to provide a reference for the formulation of pollution control strategies. The sampling device of VOCs online monitoring equipment generally uses a filter membrane to filter and collect the gas; the better the sealing of the sampling device, the more accurate the sampling results will be.

[0004] Existing sampling devices on the market all suffer from some degree of inadequate sealing and leakage. This is primarily because they lack sealing rings, or the sealing rings are in direct contact with the filter membrane. Furthermore, the filter membrane itself is permeable, making a complete seal impossible. When used in high-flow-rate VOCs monitoring equipment (e.g., particulate matter sampling flow rates of a few liters per minute), leakage is negligible. However, when used in low-flow-rate VOCs monitoring equipment (e.g., particulate matter sampling flow rates of a few milliliters per minute), leakage will affect the sampling results. Utility Model Content

[0005] In view of this, the present invention provides a sealed sampling membrane holder with good sealing performance and accurate sampling values, as well as an online VOCs monitoring device.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] On one hand, this utility model provides a sealed sampling membrane holder, including a membrane holder block and a membrane pressing block arranged opposite each other, wherein a membrane tray for supporting the filter membrane is provided between the membrane holder block and the membrane pressing block, wherein:

[0008] The membrane tray is cylindrical, and the bottom of the membrane tray has a porous structure. The membrane tray contains a membrane pressure ring that forms a closed loop after installation. The inner sidewall of the membrane tray has a limiting protrusion, and the lower surface of the limiting protrusion is an inclined surface that can squeeze and fix the membrane pressure ring to fix the filter membrane.

[0009] A first cavity is formed between the membrane support block and the membrane tray, and a second cavity is formed between the membrane tray and the membrane pressing block. Sealing devices are provided on the contact surfaces of the membrane support block and the membrane tray, as well as on the contact surfaces of the membrane tray and the membrane pressing block. An air inlet connector is provided on the membrane support block, and an air outlet connector is provided on the membrane pressing block.

[0010] The outer sides of the membrane support block and the membrane pressing block are provided with locking devices for squeezing and locking their relative positions.

[0011] Furthermore, the membrane pressure ring is a C-shaped membrane pressure ring with an opening;

[0012] Alternatively, the membrane pressure ring may be two semi-circular membrane pressure rings.

[0013] Furthermore, the membrane pressure ring is provided with radial through holes.

[0014] Furthermore, both the membrane support block and the membrane pressing block have sealing ring receiving grooves on their contact surfaces with the membrane tray, and the sealing device is a silicone sealing ring disposed in the sealing ring receiving groove.

[0015] Furthermore, the membrane pressing block has a receiving groove at one end near the membrane support block, the outer diameter of the membrane tray is less than or equal to the inner diameter of the receiving groove, and the membrane support block has an insertion part that mates with the receiving groove at one end near the membrane pressing block.

[0016] Furthermore, the locking device is a membrane support lock nut sleeved on the membrane pressing block. The membrane support lock nut includes an annular body and a blocking part that extends inward from the lower end of the annular body and cooperates with the outer end face of the membrane pressing block. The inner side of the upper end of the annular body is provided with an internal thread, and the membrane support block is provided with an external thread that cooperates with the internal thread on the outer side of the upper part of the insertion part.

[0017] Furthermore, the inner side of the end of the air inlet and air outlet is provided with an inverted flared opening, and a retaining sleeve is provided inside the inverted flared opening. The outer side of the air inlet and air outlet is threaded with a nut that can push the retaining sleeve to move.

[0018] Furthermore, both the first cavity and the second cavity are frustoconical, with the lower surfaces of the two frustocones facing each other.

[0019] On the other hand, this utility model provides an online VOCs monitoring device, including the aforementioned sealed sampling membrane holder.

[0020] This utility model has the following beneficial effects:

[0021] This utility model discloses a sealed sampling membrane holder and an online VOCs monitoring device, comprising a membrane holder block and a membrane pressure block arranged opposite each other. A membrane tray for supporting the filter membrane is provided between the membrane holder block and the membrane pressure block. The membrane tray is cylindrical, and a membrane pressure ring, which forms a closed loop after installation, is located inside the membrane tray. A limiting protrusion is provided on the inner side wall of the membrane tray, and the lower surface of the limiting protrusion is an inclined surface that can compress and fix the membrane pressure ring to secure the filter membrane. The inclined surface can clamp and press the membrane pressure ring, which in turn can press the filter membrane firmly, thus securing it securely. The bottom of the membrane tray has a porous structure, allowing the sampling gas to pass smoothly through the center when the sampling gas flows through the membrane tray, resulting in good sampling effect. Sealing devices are provided on the contact surfaces between the membrane holder block and the membrane tray, as well as on the contact surfaces between the membrane tray and the membrane pressure block. The filter membrane placement position is isolated by a separate component, and then the isolated component is sealed. Therefore, even when used in low-flow VOCs monitoring equipment, it still maintains strong sealing performance and accurate sampling values. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall structure of the sealed sampling membrane holder of this utility model;

[0024] Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure;

[0025] Figure 3 for Figure 1 A schematic diagram of the structure of the middle membrane block, wherein (a) is a cross-sectional view and (b) is a bottom view;

[0026] Figure 4 for Figure 1 A schematic diagram of the structure of the medium-membrane tray, wherein (a) is a cross-sectional view and (b) is a top view;

[0027] Figure 5 for Figure 1 A schematic diagram of the structure of the middle membrane support block, wherein (a) is a cross-sectional view and (b) is a top view;

[0028] Figure 6 for Figure 1A schematic diagram of the structure of the middle membrane pressure ring, wherein (a) is a cross-sectional view and (b) is a top view;

[0029] Figure 7 for Figure 1 A schematic diagram of the structure of the middle membrane locking nut, wherein (a) is a cross-sectional view and (b) is a bottom view;

[0030] Figure 8 for Figure 1 A schematic diagram of the structure of the nut, where (a) is the front view and (b) is the cross-sectional view along the AA direction. Detailed Implementation

[0031] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0032] It should be understood that the described embodiments are merely some embodiments of this utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0033] On the one hand, this utility model provides a sealed sampling membrane holder, which can be applied to the automatic sampling device of VOCs online monitoring equipment, such as... Figure 1-8 As shown, it includes a membrane support block 3 and a membrane pressing block 1 arranged opposite to each other, and a membrane tray 2 for supporting the filter membrane 9 is provided between the membrane support block 3 and the membrane pressing block 1, wherein:

[0034] The membrane tray 2 is cylindrical, and the bottom of the membrane tray 2 has a porous structure. The membrane tray 2 is provided with a membrane pressure ring 7 that forms a closed ring after installation. The inner side wall of the membrane tray 2 is provided with a limiting protrusion 21. The lower surface of the limiting protrusion 21 is an inclined surface 211 that can squeeze and fix the membrane pressure ring 7 to fix the filter membrane 9.

[0035] A first cavity 31 is formed between the membrane support block 3 and the membrane tray 2, and a second cavity 11 is formed between the membrane tray 2 and the membrane pressing block 1. Sealing devices are provided on the contact surfaces of the membrane support block 3 and the membrane tray 2, as well as on the contact surfaces of the membrane tray 2 and the membrane pressing block 1. An air inlet connector 32 is provided on the membrane support block 3, and an air outlet connector 12 is provided on the membrane pressing block 1.

[0036] The outer sides of the membrane support block 3 and the membrane pressure block 1 are provided with locking devices for squeezing and locking their relative positions.

[0037] In use, first install the filter membrane 9 in the membrane tray 2 and fix the filter membrane 9 with the membrane pressure ring 7. At this time, the membrane pressure ring 7 is pressed and fixed by the inclined surface 211 of the limiting protrusion 21 on the inner side wall of the membrane tray 2. Then, place the membrane tray 2 between the membrane support block 3 and the membrane pressure block 1 that are arranged opposite to each other. Then, use the sealing device to seal the contact surface between the membrane support block 3 and the membrane tray 2 and the contact surface between the membrane tray 2 and the membrane pressure block 1. Use the locking device to press and lock the membrane support block 3 and the membrane pressure block 1 on the outside. Finally, install the sealed sampling membrane support into the sampling device of the VOCs online monitoring equipment for use.

[0038] This invention relates to a sealed sampling membrane holder, comprising a membrane holder block and a membrane pressing block arranged opposite each other. A membrane tray, cylindrical in shape, is positioned between the membrane holder block and the membrane pressing block to support the filter membrane. Inside the membrane tray is a membrane pressing ring that forms a closed loop after installation. The inner wall of the membrane tray has a limiting protrusion, the lower surface of which is an inclined surface capable of pressing and fixing the membrane pressing ring to secure the filter membrane. The inclined surface can clamp and compress the membrane pressing ring, which in turn can press the filter membrane firmly in place. The bottom of the membrane tray has a porous structure, allowing the sampling gas to pass smoothly through the center when it passes through the tray, resulting in good sampling performance. Sealing devices are provided on the contact surfaces between the membrane holder block and the membrane tray, as well as on the contact surfaces between the membrane tray and the membrane pressing block. The filter membrane placement position is isolated by a separate component, and this isolated component is then sealed. Therefore, even when used in low-flow VOCs monitoring equipment, it still maintains strong sealing performance and accurate sampling values.

[0039] like Figure 6 As shown, the membrane pressure ring 7 can be any structural form readily conceived by those skilled in the art. To facilitate insertion and removal of the membrane pressure ring 7 from the membrane tray 2, the membrane pressure ring 7 can be a C-shaped membrane pressure ring with an opening. The C-shaped structure can generate large elastic deformation when squeezed by the inclined surface 211 of the restricted position protrusion 21, tightly adhering to the filter membrane, achieving a reliable seal, reducing the risk of leakage, and thus making the sampling values ​​more accurate.

[0040] Alternatively, the membrane pressure ring 7 can be two semi-circular membrane pressure rings. Two semi-circular membrane pressure rings are more flexible in installation and removal, and they apply more uniform pressure to the membrane. This uniform pressure can ensure the stability of the filter membrane during use, thereby making the sampling values ​​more accurate.

[0041] To facilitate the disassembly of the membrane pressure ring 7, a radial through hole 71 may be provided on the membrane pressure ring 7, so that the membrane pressure ring 7 can be disassembled (hooked out) with a tool (such as an iron hook).

[0042] like Figure 2 , Figure 3 and Figure 5As shown, both the membrane support block 3 and the membrane pressure block 1 have sealing ring receiving grooves 60 on their contact surfaces with the membrane tray 2, and the sealing device is a silicone sealing ring 6 installed in the sealing ring receiving groove 60. In this way, the two silicone sealing rings 6 seal the contact surfaces of the membrane tray 2 with the membrane support block 3 and the membrane pressure block 1, avoiding the influence of gap leakage, further enhancing the sealing performance, and improving the accuracy of the sampling values.

[0043] like Figure 3-5 As shown, the membrane pressing block 1 may have a receiving groove 13 at one end near the membrane support block 3. The outer diameter of the membrane tray 2 is less than or equal to the inner diameter of the receiving groove 13. The membrane support block 3 has an insertion part 33 that mates with the receiving groove 13 at one end near the membrane pressing block 1. In use, the membrane tray 2 is placed into the receiving groove 13, and then the insertion part 33 is inserted into the receiving groove 13. This not only makes the assembly of the membrane pressing block 1, membrane tray 2 and membrane support block 3 more convenient, but also enhances the sealing effect on the membrane tray 2.

[0044] like Figure 2 and Figure 7 As shown, the locking device can be a membrane support lock nut 8 sleeved on the membrane pressing block 1. The membrane support lock nut 8 includes an annular body 81 and a blocking part 82 extending inward from the lower end of the annular body 81 and cooperating with the outer end face of the membrane pressing block 1. The inner side of the upper end of the annular body 81 is provided with an internal thread, and the membrane support block 3 is provided with an external thread on the outer side of the upper part of the insertion part 33, which cooperates with the internal thread. In this way, the membrane support lock nut 8 can pass through the membrane pressing block 1 and engage with the membrane support block 3 through the thread, that is, it can compress and lock the membrane pressing block 1 and the membrane support block 3.

[0045] like Figure 2 and Figure 8 As shown, the inner sides of the ends of the air inlet connector 32 and the air outlet connector 12 can be provided with a flared opening 321. A retaining sleeve 5 (specifically, a 1 / 4 PTFE retaining sleeve) is provided inside the flared opening 321. A nut 4 (specifically an M12 nut) is threaded onto the outer sides of the air inlet connector 32 and the air outlet connector 12, capable of moving the retaining sleeve 5. In this way, the retaining sleeve 5 and the nut 4 cooperate to reduce gas leakage at the air inlet connector 32 and the air outlet connector 12, thereby improving the accuracy of the sampling results.

[0046] like Figure 2 As shown, both the first cavity 31 and the second cavity 11 can be frustoconical, with the lower surfaces of the two frustocones facing each other. This ensures a smooth and stable airflow, reduces the possibility of leakage, and improves sampling accuracy.

[0047] In summary, the core of this invention lies in using a separate component to isolate the filter membrane placement area, and then sealing the isolated component. Specifically:

[0048] Filter membrane isolation space:

[0049] The filter membrane 9 is placed on the upper side of the inner space of the membrane tray 2, and then the opening of the membrane pressure ring 7 is compressed and placed in the inner space of the membrane tray 2. The vertical inclined surface 211 of the membrane tray 2 clamps and presses the membrane pressure ring 7, and the membrane pressure ring 7 clamps and presses the filter membrane 9, thus fixing the filter membrane 9. The bottom of the membrane tray 2 has a porous structure, so that when the sampling gas flows through the membrane tray, the sampling gas can pass smoothly through the middle. The membrane pressure ring 7 has an open design, which makes it easy to put into and take out of the membrane tray 2.

[0050] Seal the isolation space:

[0051] Axial sealing: Composed of membrane pressure block 1, membrane support block 3, membrane support lock nut 8, and silicone sealing ring 6. First, place the two silicone sealing rings 6 into the sealing ring receiving grooves 60 of membrane pressure block 1 and membrane support block 3 respectively; then align the membrane pressure block 1 and membrane support block 3 with the upper and lower surfaces of the membrane tray 2; then place the whole assembly into the membrane support lock nut 8, so that the threaded joint of the membrane pressure block 1 passes through it, tighten the membrane support lock nut 8, and lock it and the membrane support block 3 through the threads, so that the two silicone sealing rings 6 are pressed together, achieving axial sealing of the structure.

[0052] End-to-end sealing: Composed of nut 4, ferrule 5, membrane pressure block 1, and membrane support block 3. Membrane pressure block 1 and membrane support block 3 have connectors at both ends (i.e., air inlet connector 32 and air outlet connector 12). The outer side of the connector is threaded, and the inside of the connector is a flared opening. Place ferrule 5 inside the flared opening, tighten nut 4 from the outside to secure it, and lock ferrule 5 to achieve a line-surface compression seal.

[0053] On the other hand, this utility model provides an online VOCs monitoring device, including the aforementioned sealed sampling membrane holder. The structure of the sealed sampling membrane holder is the same as described above, and will not be repeated here.

[0054] This utility model discloses an online VOCs monitoring device, including a sealed sampling membrane holder. The sealed sampling membrane holder includes a membrane holder block and a membrane pressure block arranged opposite each other. A membrane tray for supporting the filter membrane is provided between the membrane holder block and the membrane pressure block. The membrane tray is cylindrical, and a membrane pressure ring that forms a closed loop after installation is provided inside the membrane tray. A limiting protrusion is provided on the inner side wall of the membrane tray. The lower surface of the limiting protrusion is an inclined surface that can compress and fix the membrane pressure ring to fix the filter membrane. The inclined surface can lock and press the membrane pressure ring, and the membrane pressure ring can press the filter membrane firmly. The bottom of the membrane tray has a porous structure, so that when the sampling gas flows through the membrane tray, the sampling gas can pass smoothly through the middle, resulting in good sampling effect. Sealing devices are provided on the contact surfaces between the membrane holder block and the membrane tray, as well as on the contact surfaces between the membrane tray and the membrane pressure block. The filter membrane placement position is isolated by a separate component, and then the isolated component is sealed. In this way, even when used in a low-flow VOCs monitoring device, it can still have strong sealing performance and accurate sampling values.

[0055] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A sealed sampling membrane holder, characterized in that, The filter includes a membrane support block and a membrane pressing block arranged opposite each other, with a membrane tray for supporting the filter membrane provided between the membrane support block and the membrane pressing block, wherein: The membrane tray is cylindrical, and the bottom of the membrane tray has a porous structure. The membrane tray contains a membrane pressure ring that forms a closed loop after installation. The inner sidewall of the membrane tray has a limiting protrusion, and the lower surface of the limiting protrusion is an inclined surface that can squeeze and fix the membrane pressure ring to fix the filter membrane. A first cavity is formed between the membrane support block and the membrane tray, and a second cavity is formed between the membrane tray and the membrane pressing block. Sealing devices are provided on the contact surfaces of the membrane support block and the membrane tray, as well as on the contact surfaces of the membrane tray and the membrane pressing block. An air inlet connector is provided on the membrane support block, and an air outlet connector is provided on the membrane pressing block. The outer sides of the membrane support block and the membrane pressing block are provided with locking devices for squeezing and locking their relative positions.

2. The sealed sampling membrane holder according to claim 1, characterized in that, The membrane pressure ring is a C-shaped membrane pressure ring with an opening; Alternatively, the membrane pressure ring may be two semi-circular membrane pressure rings.

3. The sealed sampling membrane holder according to claim 1, characterized in that, The membrane pressure ring is provided with radial through holes.

4. The sealed sampling membrane holder according to claim 1, characterized in that, The membrane support block and the membrane pressing block are both provided with sealing ring receiving grooves on their contact surfaces with the membrane tray, and the sealing device is a silicone sealing ring disposed in the sealing ring receiving groove.

5. The sealed sampling membrane holder according to claim 1, characterized in that, The membrane pressing block has a receiving groove at one end near the membrane support block, the outer diameter of the membrane tray is less than or equal to the inner diameter of the receiving groove, and the membrane support block has an insertion part that mates with the receiving groove at one end near the membrane pressing block.

6. The sealed sampling membrane holder according to claim 5, characterized in that, The locking device is a membrane support lock nut sleeved on the membrane pressing block. The membrane support lock nut includes an annular body and a blocking part that extends inward from the lower end of the annular body and cooperates with the outer end face of the membrane pressing block. The inner side of the upper end of the annular body is provided with an internal thread, and the membrane support block is provided with an external thread that cooperates with the internal thread on the outer side of the upper part of the insertion part.

7. The sealed sampling membrane holder according to claim 1, characterized in that, The inner side of the end of the air inlet and air outlet is provided with an inverted flared opening, and a retaining sleeve is provided inside the inverted flared opening. The outer side of the air inlet and air outlet is threaded with a nut that can push the retaining sleeve to move.

8. The sealed sampling membrane holder according to claim 1, characterized in that, Both the first cavity and the second cavity are frustum-shaped, with the lower surfaces of the two frustums facing each other.

9. A VOCs online monitoring device, characterized in that, Includes the sealed sampling membrane holder as described in any one of claims 1-8.

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