A volatile organic compound sampling device

Abstract

The present invention discloses a volatile organic compound sampling device, which includes a storage box body, a pretreatment box body and an extraction pipe. The storage box body, the pretreatment box body and the extraction pipe are connected in sequence. The storage box body includes an air inlet box, a sampling box and an air outlet box. A plurality of heating sleeves are provided in the sampling box, and a sampling pipe is provided in the heating sleeve. A nitrogen gas tank is also provided in the sampling box, and the nitrogen gas tank is communicated with the air inlet box. An air inlet conveying channel and an air outlet conveying channel are respectively provided in the air inlet box and the air outlet box. Electromagnetic control valves are provided on the nitrogen gas tank, the air inlet conveying channel and the air outlet conveying channel. A locking structure is provided between the air outlet box and the sampling box, and between the air inlet box and the sampling box. The pretreatment box body is connected with a copper extraction pipe through a quick-insert structure; the device can be quickly connected to the sampling system, ensure that the sampling flow accuracy is within the specified standard, is convenient for storage and transportation after sampling, and can stably discharge volatile organic compounds during detection, effectively improving the detection efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of organic matter detection systems, and particularly relates to a volatile organic compound sampling device. Background Art

[0002] According to the definition of the World Health Organization, volatile organic compounds (VOCs) are organic compounds at 50°C - 250°C. Volatile organic compounds are a type of air pollutant, which are toxic and will participate in photochemical reactions under light conditions, forming photochemical smog, generating pollutants such as ozone and peroxyacetyl nitrate. Qualitatively and quantitatively determining different types of volatile organic compounds accurately is the core of control; there are corresponding collection and detection standards for VOCs in each field to regulate and implement; currently, during collection, an extraction tube is placed at the sampling point, and then the extraction tube is connected to a sampling tube. The sampling tube contains special absorption fillers, so that volatile organic compounds stay on the absorption fillers in the sampling tube. Then the sampling tube is connected to an air pump, and the collection can be completed by pumping air through the air pump. However, the current collection device still has the following disadvantages:

[0003] 1. Currently, extraction tubes are all made of silica gel tubes, with a flow accuracy maintained between 0.1 - 1 L / min, and the diameter of the silica gel tubes is mostly 0.5 cm. After the standards for volatile organic compounds emerged, further regulations were imposed on the extraction tubes, and the flow accuracy became between 0.01 - 0.1 L / min, with the flow accuracy rising by one level. However, the silica gel tubes cannot be made too thin and cannot meet the requirements. Moreover, volatile organic compounds will remain in the silica gel tubes during collection and thus cannot be discharged, affecting the detection.

[0004] 2. In an environment with severe moisture, when directly collecting through the extraction tube, the volatile organic compounds in the collected gas are mixed with moisture and enter the sampling tube. On the one hand, it affects the final detection, and on the other hand, it makes the absorption quality of the absorption fillers in the sampling tube worse, affecting the use.

[0005] 3. Currently, sampling generally requires multiple samplings to ensure the accuracy of the sampling results. Therefore, it is necessary to frequently disassemble and assemble multiple sampling tubes, and the disassembly and assembly operations are very cumbersome.

[0006] 4. After the sampling tube is sent to the laboratory, a separate device is required to heat the sampling tube to release the volatile organic compounds in the absorption fillers. After the release is completed, the sampling tube needs to be cleaned separately. The release and cleaning cannot be completed in one device. Therefore, it is also necessary to frequently disassemble and assemble the sampling tube.

[0007] 5. The absorption fillers in the sampling tube have a strong absorption capacity for organic compounds in the air. Therefore, during transportation, once the sampling tube is in frequent contact with the outside air, the absorption fillers are likely to adsorb the volatile organic compounds in the external air, resulting in inaccurate detection results. Summary of the Invention

[0008] The technical problem to be solved by the present invention is as follows: a volatile organic compound sampling device, which can be quickly connected to a sampling system, ensure that the sampling flow accuracy is within the specified standards, effectively pre-treat the sampling gas, is convenient for storage and transportation after sampling, and can stably discharge volatile organic compounds during detection, effectively improving the detection efficiency.

[0009] To solve the above technical problem, the technical solution of the present invention is: a volatile organic compound sampling device, including a storage box body, a pre-treatment box body and an exhaust pipe. The storage box body, the pre-treatment box body and the exhaust pipe are sequentially connected in communication. The storage box body includes an air inlet box, a sampling box and an air outlet box. The air outlet box, the sampling box and the air inlet box are sequentially stacked and detachably installed and fixed. A plurality of heating sleeves are provided in the sampling box, and corresponding sampling pipes are provided in the heating sleeves. A nitrogen gas tank is also provided in the sampling box, and the nitrogen gas tank is communicated with the air inlet box. An air inlet conveying channel and an air outlet conveying channel that are hermetically and cooperatively connected to the two ends of the sampling pipe are respectively provided in the air inlet box and the air outlet box. Each sampling pipe is pressed and fixed through the air outlet box and the air inlet box. Electromagnetic control valves that are convenient to open or close are provided on the nitrogen gas tank, the air inlet conveying channel and the air outlet conveying channel. The air outlet box has the same structure as the air inlet box. A locking structure is provided between the air outlet box and the sampling box, and between the air inlet box and the sampling box. An air inlet pipe of the box body that is convenient for air inlet is provided on the air inlet box, and an air outlet pipe of the box body that is convenient for air outlet is provided on the air outlet box. Flow control valves that can be opened and closed are provided on the air inlet pipe of the box body and the air outlet pipe of the box body. The ends of the air inlet pipe of the box body and the air outlet pipe of the box body are both quick-insert structures; the air inlet pipe of the box body is communicated with the pre-treatment box body that pre-treats the sampling gas through the quick-insert structure, and the pre-treatment box body is connected with a copper exhaust pipe through the quick-insert structure; a replacement connecting pipe with a valve is also connected between the air inlet box and the air outlet box.

[0010] As a preferred solution, an air inlet and an air outlet are provided on the pre-treatment box body. A box body air inlet pipe and a box body air outlet pipe are provided at the air inlet and the air outlet. The air inlet pipe of the box body is communicated with the box body air outlet pipe through the quick-insert structure. Pre-treatment valves that are convenient to open and close are provided on the box body air inlet pipe and the box body air outlet pipe. The ends of the box body air inlet pipe and the box body air outlet pipe are both quick-insert structures. A pre-treatment pipe that is communicated with the air inlet and the air outlet is provided inside the pre-treatment box body. The pre-treatment pipe includes a heating part and a condensing part. The heating part is located upstream of the condensing part. A condensate collection port is provided at the low position of the condensing part. A condensate collection bottle that is convenient for disassembly and assembly is provided at the condensate collection port. An exhaust pipe is connected to the air outlet pipe through the quick-insert structure.

[0011] As a preferred solution, the intake box includes an intake chamber, and a number of intake delivery holes are formed in the intake chamber. Each intake delivery hole is correspondingly communicated with the intake delivery channel one by one. An upper guiding inclined groove for pressing and sealing the sampling tube is formed at the lower end of the intake delivery channel, and the box body intake pipeline is communicated with the intake chamber; the outlet box includes an outlet chamber, and a number of outlet delivery holes are formed in the outlet chamber. Each outlet delivery hole is correspondingly communicated with the outlet delivery channel one by one. A lower guiding inclined groove for pressing and sealing the sampling tube is formed at the upper end of the outlet delivery channel, and the box body outlet pipeline is communicated with the outlet chamber.

[0012] As a preferred solution, a purging pipeline extending into the intake chamber is provided on the nitrogen tank, and a quick-insert structure convenient for disassembly and assembly is also provided on the purging pipeline; elastic gaskets in contact with the sampling tube are provided on both the upper guiding inclined groove and the lower guiding inclined groove.

[0013] As a preferred solution, the pretreatment pipe is a U-shaped pipe. The heating part includes a heating pipe section located on the U-shaped pipe and communicated with the air inlet, and a heating wire is provided on the heating pipe section. The condensation part includes a condensation pipe section communicated downstream of the heating pipe section, and a condensation device for actively cooling is provided on the condensation pipe section. A exhaust pipe section is communicated downstream of the condensation pipe section, and the exhaust pipe section is communicated with the air outlet.

[0014] As a preferred solution, the condensation pipe section includes a first pipe section and a second pipe section. The position of the first pipe section is higher than that of the second pipe section, and the first pipe section and the second pipe section are communicated through a diversion pipe section. Condensation devices are provided on the first pipe section, the second pipe section and the diversion pipe section.

[0015] As a preferred solution, both the first pipe section and the second pipe section are vertically installed, and the condensate collection port is arranged at the bottom of the second pipe section. The condensate collection port and the condensate collection bottle are fixed by screw connection.

[0016] As a preferred solution, the diameter of the heating pipe section is smaller than that of the condensation pipe section.

[0017] As a preferred solution, the inner wall of the air extraction pipe is covered with an inert coating through inert treatment.

[0018] As a preferred solution, a handle convenient for grasping is rotatably installed on the intake box.

[0019] After adopting the above technical solution, the effects of the present invention are as follows: Since the volatile organic compound sampling device includes a storage box body, a pretreatment box body and an extraction pipe, the storage box body, the pretreatment box body and the extraction pipe are connected in sequence. The storage box body includes an intake box, a sampling box and an outlet box. The outlet box, the sampling box and the intake box are stacked and detachably installed and fixed in sequence. A number of heating sleeves are provided in the sampling box, and corresponding sampling pipes are provided in the heating sleeves. A nitrogen gas tank is also provided in the sampling box, and the nitrogen gas tank is communicated with the intake box. Intake conveying channels and outlet conveying channels corresponding to the two ends of the sampling pipe are respectively provided in the intake box and the outlet box. Each sampling pipe is pressed and fixed through the outlet box and the intake box. Electromagnetic control valves that are convenient to open or close are provided on the nitrogen gas tank, the intake conveying channel and the outlet conveying channel. The outlet box has the same structure as the intake box. A buckle structure is provided between the outlet box and the sampling box, and between the intake box and the sampling box. A box body intake pipe convenient for intake is provided on the intake box, and a box body outlet pipe convenient for outlet is provided on the outlet box. Flow control valves that can be opened and closed are provided on the box body intake pipe and the box body outlet pipe. The ends of the box body intake pipe and the box body outlet pipe are both quick-insert structures. The box body intake pipe is communicated with the pretreatment box body for pre-treating the sampled gas through the quick-insert structure. The pretreatment box body is connected with a copper extraction pipe through the quick-insert structure. A replacement connecting pipe with a valve is also connected between the intake box and the outlet box. First, place the extraction pipe at the sampling point, then connect the outlet pipe to the air extraction pump, open the flow control valve, open the first electromagnetic control valve corresponding in the intake box and the outlet box, and the air extraction pump starts to work. At this time, the sampled gas enters the extraction pipe, then enters the pretreatment box body for processing of the sampled gas. The processed sampled gas enters the box body intake pipe, then enters the intake box. The sampled gas then enters the sampling pipe along the intake conveying channel from the intake box. The volatile organic compounds in the sampled gas are absorbed by the absorption filler. The remaining sampled gas enters the outlet box through the outlet conveying channel in the outlet box, and finally is discharged from the outlet pipe. Then close the first electromagnetic control valve in the intake box and the outlet box, open the corresponding second electromagnetic control valve, and the sampled gas enters the corresponding sampling pipe. Repeat the operation to discharge the remaining sampled gas. Do this repeatedly until enough sampled pipes are sampled. Finally, close the electromagnetic control valves corresponding to all sampling pipes, stop the air extraction pump, remove the extraction pipe from the sampling point, and separate the box body intake pipe from the pretreatment box body;Then, move the storage box body and the sampling pump as a whole to a clean environment. Open the valve on the replacement connection pipe and start the air extraction pump to continuously extract air, so that the external clean air enters the intake box, the replacement connection pipe, and the outlet box. After replacing the sampling gas in the intake box and the outlet box, stop the air extraction pump and close the valve on the replacement connection pipe. Finally, separate the box outlet pipe from the air extraction pump, and then close the flow control valve. At this time, the sampling pipe is stored in the sampling box without contacting the external gas, and volatile organic compounds can be effectively preserved. When conducting detection, connect the box outlet pipe and the box inlet pipe to the detection instrument, and let the heating sleeve outside the specified sampling pipe work to heat it. The volatile organic compounds in the sampling pipe start to volatilize, and the volatile organic compounds in the sampling pipe will separate from the absorption filler and be discharged from the outlet pipe, thus completing the detection. Each sampling pipe can be subjected to the release detection operation of volatile organic compounds in the above-mentioned manner. The entire process does not require frequent disassembly and assembly of the sampling pipe, and the operation is very convenient, effectively improving the detection efficiency. After the detection is completed, separate the box outlet pipe and the box inlet pipe from the detection instrument, and then cleaning and purging work can be carried out. All heating sleeves can be started to heat all sampling pipes, and nitrogen purging can be performed to purge all the volatile organic compounds in the sampling pipe, which is convenient for the next use. The outlet box, the sampling box, and the inlet box are stacked in sequence and can be detachably installed and fixed, which is convenient for replacing the sampling pipe.;

[0020] Also, since the pretreatment box body is provided with an air inlet and an air outlet, a box inlet pipe and a box outlet pipe are provided at the air inlet and the air outlet. The box inlet pipe is communicated with the box outlet pipe through a quick-insert structure. Pretreatment valves that are convenient to open and close are provided on the box inlet pipe and the box outlet pipe. The ends of the box inlet pipe and the box outlet pipe are both quick-insert structures. A pretreatment pipe communicating with the air inlet and the air outlet is opened inside the pretreatment box body. The pretreatment pipe includes a heating part and a condensation part. The heating part is located upstream of the condensation part. A condensate collection port is provided at the low position of the condensation part. A condensate collection bottle that is convenient to disassemble and assemble is provided at the condensate collection port. A suction pipe is connected to the outlet pipe through a quick-insert structure. The sampling gas enters the suction pipe, then enters the box inlet pipe, and enters the heating part of the pretreatment pipe from the air inlet for heating. After heating, it enters the condensation part for cooling. The moisture is separated and enters the condensate collection bottle through the condensate collection port for collection. The sampled gas after condensation then discharges from the air outlet and enters the box outlet pipe, and then enters the intake box from the box outlet pipe. In this way, the moisture in the sampled gas can be effectively removed, ensuring the good dryness of the sampled gas, and also ensuring that the sampling flow accuracy is within the specified standard, improving the sampling and enhancing the detection accuracy.

[0021] Also, since the intake box includes an intake chamber, a number of intake delivery holes are provided in the intake chamber, and each intake delivery hole is in one-to-one correspondence and communication with the intake delivery channel. An upper guiding inclined groove for pressing and sealing the sampling tube is provided at the lower end of the intake delivery channel, and the box body intake pipeline is connected to the intake chamber; the outlet box includes an outlet chamber, a number of outlet delivery holes are provided in the outlet chamber, and each outlet delivery hole is in one-to-one correspondence and communication with the outlet delivery channel. A lower guiding inclined groove for pressing and sealing the sampling tube is provided at the upper end of the outlet delivery channel, and the box body outlet pipeline is connected to the outlet chamber; in this way, the intake chamber and the intake delivery channel are both in communication, enabling the sampling gas to enter any one of the sampling tubes. When the valve is opened, the sampling gas can quickly enter the corresponding sampling tube and then be discharged from the outlet delivery channel in the outlet box. Moreover, the upper guiding inclined groove and the lower guiding inclined groove have a certain slope, so that the upper guiding inclined groove and the lower guiding inclined groove cooperate with each other to quickly fix and seal the sampling tube. When the intake box body is installed on the sampling box, it can automatically perform positioning and adjustment, thus ensuring accurate installation.

[0022] Also, since a purging pipeline extending into the intake chamber is provided on the nitrogen gas tank, and a quick-insert structure for convenient disassembly and assembly is also provided on the purging pipeline; elastic gaskets in contact with the sampling tube are provided on both the upper guiding inclined groove and the lower guiding inclined groove; in this way, the purging pipeline can be quickly disassembled and assembled, facilitating the disassembly and assembly between the intake box and the sampling box and improving practicality; the elastic gaskets can make the intake box and the outlet box have a certain elasticity during installation, effectively pressing and sealing both ends of the sampling tube and improving the sampling efficiency.

[0023] Also, since the pretreatment tube is a U-shaped tube, the heating part includes a heating tube section located on the U-shaped tube and communicating with the intake port, and a heating wire is provided on the heating tube section. The condensation part includes a condensation tube section communicating downstream of the heating tube section, and a condensation device for active cooling is provided on the condensation tube section. A discharge pipe section is connected downstream of the condensation tube section, and the discharge pipe section is connected to the outlet port; the U-shaped tube can effectively help the condensate generated during condensation in the condensation tube section to accumulate effectively, facilitating collection and enabling the sampling gas to be effectively discharged from the discharge pipe section, making the structure more reasonable.

[0024] Also, since the condensation tube section includes a first tube section and a second tube section, the position of the first tube section is higher than that of the second tube section, and the first tube section and the second tube section are connected through a diversion tube section. Condensation devices are provided on the first tube section, the second tube section, and the diversion tube section; when the position of the first tube section is higher than that of the second tube section, the condensate will flow from high to low through the diversion tube section, ensuring that the condensate can be effectively accumulated.

[0025] Also, since both the first pipe section and the second pipe section are vertically installed, and the condensate collection port is arranged at the bottom of the second pipe section, the condensate collection port and the condensate collection bottle are fixed by threaded connection; the vertical installation enables the condensate to automatically fall due to gravity and accumulate, facilitating collection. After the condensate accumulates, it enters the condensate collection bottle from the condensate collection port. When the bottle is full, the condensate collection bottle can be removed by rotation and a new one can be replaced to continue collection. The structure is simple and ensures good collection effect.

[0026] Also, since the diameter of the heating pipe section is smaller than that of the condensation pipe section; this enables the heating pipe section to be heated conveniently, the temperature of the sampling gas to rise quickly, and after entering the condensation pipe section, the space becomes larger, facilitating heat dissipation and cooling.

[0027] Also, since the inner wall of the suction pipe is covered with an inert coating through inert treatment, the inside of the suction pipe is smooth and durable, preventing the volatile organic compounds in the sampling gas from reacting with or adhering to the inner wall of the suction pipe, which may affect subsequent detection.

[0028] Also, since a handle convenient for grasping is rotatably installed on the air inlet box, it is convenient to move the whole after sampling is completed. Brief Description of the Drawings

[0029] The present invention will be further described below in conjunction with the drawings and embodiments.

[0030] Figure 1 is a perspective view of an embodiment of the present invention;

[0031] Figure 2 is a schematic structural diagram inside an embodiment of the present invention;

[0032] Figure 3 is a front view of the pretreatment box body and the suction pipe of an embodiment of the present invention;

[0033] Figure 4 is a schematic structural diagram inside the storage box of an embodiment of the present invention;

[0034] Figure 5 is a schematic structural diagram of the bottom of the air inlet box of an embodiment of the present invention;

[0035] Figure 6 is Figure 5 a schematic structural diagram at A-A;

[0036] Figure 7 is a schematic structural diagram inside the sampling box of an embodiment of the present invention;

[0037] Figure 8 is a schematic structural diagram of the air outlet box of an embodiment of the present invention;

[0038] In the attached drawings: 1. Intake box; 2. Sampling box; 3. Exhaust box; 4. Heating sleeve; 5. Sampling tube; 6. Nitrogen tank; 7. Box intake pipeline; 8. Box exhaust pipeline; 9. Flow control valve; 10. Groove seat; 11. Lock seat; 12. Lock body; 13. Snap ring; 14. Intake chamber; 141. Intake delivery hole; 15. Intake delivery channel; 16. Upper guiding chute; 17. Exhaust chamber; 18. Exhaust delivery hole; 19. Lower guiding chute; 20. Exhaust delivery channel; 21. Elastic washer; 22. Purge pipeline; 23. Gas quick connector; 24. Electromagnetic control valve; 25. Control screen; 26. Handle; 27. Pretreatment box body; 28. Intake port; 29. Exhaust port; 30. Box intake pipeline; 31. Box exhaust pipeline; 32. Pretreatment valve; 33. Suction pipe; 34. Heating pipe section; 35. Heating wire; 36. Condensing pipe section; 361. First pipe section; 362. Second pipe section; 363. Diversion pipe section; 37. Exhaust pipe section; 38. Thermoelectric cooler; 39. Condensate collection port; 40. Condensate collection bottle; 41. First replacement pipeline; 42. Second replacement pipeline; 43. Connecting pipeline; 44. Ball valve. Detailed implementation manners

[0039] The present invention will be further described in detail below through specific embodiments.

[0040] Such as Figures 1 to 8As shown in the figure, a volatile organic compound sampling device includes a storage box body, a pretreatment box body 27 and an exhaust pipe 33. The storage box body, the pretreatment box body 27 and the exhaust pipe 33 are connected in sequence. The storage box body includes an air inlet box 1, a sampling box 2 and an air outlet box 3. The air outlet box 3, the sampling box 2 and the air inlet box 1 are stacked and detachably installed and fixed in sequence. A plurality of heating sleeves 4 are provided in the sampling box 2, and corresponding sampling pipes 5 are provided in the heating sleeves 4. A nitrogen gas tank 6 is also provided in the sampling box 2. The nitrogen gas tank 6 is communicated with the air inlet box 1. Air inlet conveying channels 15 and air outlet conveying channels 20 corresponding to the two ends of the sampling pipe 5 are respectively provided in the air inlet box 1 and the air outlet box 3. Each sampling pipe 5 is fixedly pressed by the air outlet box 3 and the air inlet box 1. Electromagnetic control valves 24 that are convenient to open or close are provided on the nitrogen gas tank 6, the air inlet conveying channel 15 and the air outlet conveying channel 20. The air outlet box 3 has the same structure as the air inlet box 1. A locking structure is provided between the air outlet box 3 and the sampling box 2, and between the air inlet box 1 and the sampling box 2. An air inlet pipe 7 of the box body that is convenient for air inlet is provided on the air inlet box 1, and an air outlet pipe 8 of the box body that is convenient for air outlet is provided on the air outlet box 3. Flow control valves 9 that can be switched are provided on both the air inlet pipe 7 of the box body and the air outlet pipe 8 of the box body. The ends of the air inlet pipe 7 of the box body and the air outlet pipe 8 of the box body are both quick-insert structures. The air inlet pipe 7 of the box body is communicated with the pretreatment box body 27 that performs pretreatment on the sampled gas through the quick-insert structure, and the pretreatment box body 27 is connected with a copper exhaust pipe 33 through the quick-insert structure.

[0041] In this embodiment, the air inlet box 1, the sampling box 2 and the air outlet box 3 are all cuboid structures with the same cross-sectional size, and can be stacked and detachably installed and fixed in sequence. The locking structure includes groove seats 10 fixedly installed on the air inlet box 1 and the air outlet box 3 and a lock seat 11 fixed on the sampling box 2. A lock body 12 that rotates around a pin shaft fixed on the lock seat 11 is provided on the lock seat 11. A buckle 13 corresponding to the groove seat 10 is hinged on the lock body 12. In this way, by buckling the buckle 13 on the groove seat 10, and then rotating the lock body 12 to make the lock body 12 cover on the lock seat 11, the buckle 13 firmly buckles the groove seat 10, so that the air inlet box 1 and the sampling box 2 or the air outlet box 3 and the sampling box 2 are firmly pressed and fixed together.

[0042] Further, an air inlet 28 and an air outlet 29 are formed on the pretreatment box body 27. A box body air inlet pipe 30 and a box body air outlet pipe 31 are provided at the air inlet 28 and the air outlet 29. The box body air inlet pipe 7 is communicated with the box body air outlet pipe 31 through a quick-connect structure. Pretreatment valves 32 for convenient opening and closing are provided on the box body air inlet pipe 30 and the box body air outlet pipe 31. The ends of the box body air inlet pipe 30 and the box body air outlet pipe 31 are both quick-connect structures. A pretreatment pipe communicating with the air inlet 28 and the air outlet 29 is formed inside the pretreatment box body 27. The pretreatment pipe includes a heating part and a condensation part. The heating part is located upstream of the condensation part. A condensate collection port 39 is provided at the low position of the condensation part. A condensate collection bottle 40 for convenient disassembly and assembly is provided at the condensate collection port 39. An air extraction pipe 33 is connected to the air outlet pipe through a quick-connect structure; the air extraction pipe 33 is generally made of brass material.

[0043] The quick-connect structure includes a gas quick connector 23. A male or female head of the gas quick connector 23 is connected to the end of the air inlet pipe. Similarly, a male or female head of the gas quick connector 23 is connected to the end of the air outlet pipe. At the same time, a female or male head adapted to the gas quick connector 23 at the air inlet pipe is provided on the air extraction pipe 33, so that quick disassembly and assembly can be completed, improving efficiency.

[0044] As Figure 4 shown, the air inlet box 1 includes an air inlet chamber 14. A plurality of air inlet conveying holes 141 are formed on the air inlet chamber 14. Each air inlet conveying hole 141 is correspondingly communicated with the air inlet conveying channel 15. An upper guiding inclined groove 16 for pressing and sealing the sampling pipe 5 is formed at the lower end of the air inlet conveying channel 15. The box body air inlet pipe 7 is communicated with the air inlet chamber 14; the air inlet conveying holes 141 are correspondingly connected with electromagnetic control valves 24 one by one. The electromagnetic control valves 24 are then connected to the corresponding air inlet conveying channels 15. In this way, the sampling gas can enter any one of the air inlet conveying channels 15. When the upper end of the sampling pipe 5 contacts the upper guiding inclined groove 16, the connection and sealing of the upper end of the sampling pipe 5 are completed. When sampling, a single sampling pipe 5 is required for sampling. In this way, when collecting, only any one of the electromagnetic control valves 24 needs to be opened, and the sampling gas will enter the corresponding sampling pipe 5, thus completing the sampling.

[0045] Furthermore, the air outlet box 3 includes an air outlet chamber 17. A number of air outlet conveying holes 18 are formed in the air outlet chamber 17, and each air outlet conveying hole 18 is in one-to-one correspondence and communication with the air outlet conveying channel 20. A lower guiding inclined groove 19 for pressing and sealing the sampling tube 5 is formed at the upper end of the air outlet conveying channel 20. The box body air outlet pipeline 8 is connected to the air outlet chamber 17. After the electromagnetic control valve 24 in the air inlet box 1 is opened, the electromagnetic control valve 24 in the corresponding air outlet box 3 also needs to be synchronously opened. After opening, the absorption filler in the sampling tube 5 absorbs volatile organic compounds, and the remaining gas is discharged from the sampling tube 5, then enters the air outlet chamber 17 through the air outlet conveying channel 20, and is then discharged from the box body air outlet pipeline 8. Since the structures of the air outlet box 3 and the air inlet box 1 are the same, the lower end of the sampling tube 5 contacts and seals with the lower guiding inclined groove 19, so that the sampling tube 5 is connected to the air outlet conveying channel 20, and the air outlet conveying channel 20 is sequentially connected to the electromagnetic control valve 24 and the air outlet conveying hole 18.

[0046] As Figure 1 shown, the replacement connection pipeline includes a first replacement pipeline 41 communicating with the air inlet chamber 14 and a second replacement pipeline 42 communicating with the air outlet chamber 17. Openable and closable valves and gas quick connectors 23 are provided on both the first replacement pipeline 41 and the second replacement pipeline 42. The valve is a ball valve 44, so that the first replacement pipeline 41 and the second replacement pipeline 42 can be quickly and conveniently closed. A connecting pipeline 43 is provided between the first replacement pipeline 41 and the second replacement pipeline 42. Through the connecting pipeline, the first replacement pipeline 41 and the second replacement pipeline 42 can be connected, and it does not affect the mutual disassembly between the air inlet box 1, the air outlet box 3 and the sampling box 2.

[0047] The opening and closing control by the electromagnetic control valve 24 is accurate and effective, eliminating the tediousness of manually opening and closing each one, improving efficiency. And a control screen 25 for controlling the opening and closing of the electromagnetic control valve 24 is provided on the air inlet box 1. Since sampling is carried out on each sampling tube 5 one by one during sampling, the sampling sequence needs to be marked for subsequent detection. Through the control screen 25, the sampling tube 5 and the electromagnetic control valve 24 can be displayed on the screen for convenient observation and operation, and the control screen 25 can also perform other operations, greatly improving the work efficiency.

[0048] Further, both the lower guiding chute 19 and the upper guiding chute 16 are conical grooves. In this way, when installing the sampling tube 5, the sampling tube 5 can be adjusted along the inclined plane of the conical groove. When assembling the sampling tube 5, first, the sampling box 2 is effectively fixed to the air outlet box 3. Then, the sampling tube 5 is successively placed into the heating sleeve 4. In this way, the lower end of the sampling tube 5 first contacts the lower guiding chute 19. Then, the air inlet box 1 is installed on the sampling box 2. Since the sampling tube 5 is in an inclined state in the heating sleeve 4, when the upper guiding chute 16 contacts the upper end of the sampling tube 5, the upper guiding chute 16 will press down the sampling tube 5, thereby adjusting the position of the sampling tube 5 so that the sampling tube 5 can be in a vertical state. In this way, the sampling tube 5 forms an effective sealed connection with the air inlet conveying channel 15 and the air outlet conveying channel 20, completing the installation of the sampling tube 5.

[0049] In this embodiment, a purging pipeline 22 extending into the air inlet chamber 14 is provided on the nitrogen gas tank 6, and a quick-connect structure for convenient disassembly and assembly is also provided on the purging pipeline 22; elastic gaskets 21 in contact with the sampling tube 5 are provided on both the upper guiding chute 16 and the lower guiding chute 19; the nitrogen gas tank 6 and the sampling tube 5 are jointly installed in the sampling box 2, which can effectively save space. The height of the heating sleeve 4 is less than the height of the sampling tube 5. The purging pipeline 22 is a flexible tube, and a valve for opening and closing is also provided on the purging pipeline 22. When the air inlet box 1 and the sampling box 2 are separated, the valve is closed, and the nitrogen gas tank 6 is disconnected from the air inlet chamber 14 through the quick-connect structure. When the air inlet box 1 and the sampling box 2 need to be installed together, only the nitrogen gas tank 6 and the air inlet chamber 14 need to be connected through the quick-connect structure. When installing the sampling tube 5, the elastic gasket 21 has a certain elasticity, which can further effectively compress and seal both ends of the sampling tube 5, improving the sampling efficiency.

[0050] As Figure 3 shown, the pretreatment tube is a U-shaped tube. The heating part includes a heating tube section 34 located on the U-shaped tube and communicating with the air inlet 28. A heating wire 35 is provided on the heating tube section 34. The condensation part includes a condensation tube section 36 communicating downstream of the heating tube section 34. A condensation device for active cooling is provided on the condensation tube section 36. A tail pipe section 37 is communicated downstream of the condensation tube section 36, and the tail pipe section 37 is communicated with the air outlet 29; the pretreatment box body 27 is a rectangular box body, and the heating tube section 34, the condensation tube section 36, and the tail pipe section 37 together form a U shape. The heating tube section 34 includes a tube section horizontally extending from the air inlet 28 and a tube section vertically downward at one end. By winding the heating wire 35 on the heating tube section 34, the heating tube section 34 can be effectively heated. The U-shaped tube can effectively help the condensate generated during condensation in the condensation tube section 36 to accumulate effectively, facilitating collection, so that the sampled gas can be effectively discharged from the tail pipe section 37, and the structure is more reasonable.

[0051] Further, the condenser tube section 36 includes a first tube section 361 and a second tube section 362. The first tube section 361 is located higher than the second tube section 362. The first tube section 361 and the second tube section 362 are connected by a diversion tube section 363. Condensing devices are provided on the first tube section 361, the second tube section 362, and the diversion tube section 363. The condensing device includes a thermoelectric cooler 38. The thermoelectric cooler 38 is fixedly installed on the side walls of the first tube section 361, the second tube section 362, and the diversion tube section 363. In this way, the sampling gas flowing through the first tube section 361, the second tube section 362, and the diversion tube section 363 can be cooled and condensed. Both the first tube section 361 and the second tube section 362 are vertically installed. The first tube section 361 is connected to the downstream end of the heating tube section 34. After the first tube section 361 is located higher than the second tube section 362 and the diversion tube section 363 connects the first tube section 361 and the second tube section 362, the diversion tube section 363 is in an inclined state, which is convenient for the condensate to flow. The second tube section 362 is fixedly installed at the bottom of the pretreatment box body 27. At the same time, the condensate collection port 39 is provided at the bottom of the second tube section 362. The condensate collection port 39 and the condensate collection bottle 40 are fixedly connected by a threaded connection.

[0052] The condensate collection port 39 penetrates through the second tube section 362 and the pretreatment box body 27. In this way, the condensate collection bottle 40 can be installed outside the pretreatment box body 27 and connected to the second tube section 362. By rotating the condensate collection bottle 40, the condensate collection bottle 40 can be quickly and conveniently removed, improving the convenience of replacement.

[0053] In this embodiment, a heating wire 35 for convenient heating is also provided on the air extraction pipe 33. Since the air extraction pipe 33 is made of brass, it can also be heated to a certain temperature, so as to achieve the effect of preheating in advance and ensure that the sampling gas is heated well.

[0054] Further, the diameter of the heating tube section 34 is smaller than the diameter of the condenser tube section 36. In this way, when the sampling gas enters the heating tube section 34, the space is small, and the heating tube section 34 is convenient for heating, and the temperature of the sampling gas rises quickly. Then, when it enters the condenser tube section 36, the space becomes larger, and the heat dissipation effect will be better. Cooperating with the thermoelectric cooler 38 can accelerate the cooling speed, so as to dry the sampling gas.

[0055] Still further, the inner wall of the air extraction pipe 33 is covered with an inert coating through inert treatment, so that the inside of the air extraction pipe 33 is smooth and durable, preventing the volatile organic compounds in the sampling gas from reacting or adhering to the inner wall of the air extraction pipe 33, which affects subsequent detection.

[0056] As Figure 4As shown, a handle 26 that is convenient to grasp is rotatably installed on the air inlet box 1. After collection, the entire storage box is moved. The sampling tubes 5 are all located inside the sampling box 2, which is convenient for storage and improves efficiency. However, since the sampling tubes 5 need to be stored and moved to a designated location for detection after collection, the sampling tubes 5 being inside the storage box can provide effective protection. When moving, the entire storage box can be moved by grasping the handle 26, improving convenience.

[0057] Working principle of this embodiment: The extraction pipe 33 is placed at the sampling point. The air outlet pipe 8 of the box body is connected to the air extraction pump. The pretreatment valves 32 on the box body air inlet pipe 30 and the box body air outlet pipe 31 are opened. The flow control valve 9 is opened. At the same time, the control screen 25 is used to open the corresponding first electromagnetic control valve 24 in the air inlet box 1 and the air outlet box 3. The air extraction pump works, and the sampling gas enters the extraction pipe 33. The heating wire 35 on the extraction pipe 33 preheats the sampling gas. Then the sampling gas enters the heated pipe section 34, and the heating wire 35 is also opened for further heating. The sampling gas enters the condensation pipe section 36. First, it enters the first pipe section 361. After the sampling gas cools down, condensate is formed and condenses on the side wall of the first pipe section 361 and drips along the first pipe section 361. Then it enters the diversion pipe section 363 for further cooling. The condensate generated flows together with that in the first pipe section 361 to the bottom of the second pipe section 362. After the sampling gas enters the second pipe section 362, final condensation occurs. The condensate generated also flows to the bottom of the second pipe section 362 along the side wall of the second pipe section 362 and enters the condensate collection bottle 40 through the condensate collection port 39. The dried sampling gas enters the exhaust pipe section 37 and finally is discharged from the box body air outlet pipe 31 into the box body air inlet pipe 7, and then enters the air inlet chamber 14. It enters the air inlet delivery channel 15 through the air inlet delivery hole 141, and then passes through the corresponding sampling pipe 5. The volatile organic compounds are absorbed by the absorption filler in the sampling pipe 5. The remaining sampling gas enters the air outlet delivery channel 20, then enters the air outlet chamber 17, and finally is discharged from the box body air outlet pipe 8. Then the first electromagnetic control valve 24 in the air inlet box 1 and the air outlet box 3 is closed, and the corresponding second electromagnetic control valve 24 is opened. The sampling gas enters the corresponding sampling pipe 5, and the above operations are repeated to open the valves in sequence to collect a sufficient number of sampling pipes 5; after sampling is completed, the sampling pump stops. The box body air inlet pipe 30 is separated from the extraction pipe 33, and the box body inlet pipe 7 and the box body outlet pipe 31 are separated; the entire storage box is moved to a clean environment. The ball valve 29 is opened and the sampling pump is started to continuously extract air. The external clean air enters the air inlet box 1, the first replacement pipe 27, the communication pipe 30, the second replacement pipe 28, and the air outlet box 3. After replacing the sampling gas in the air inlet box 1 and the air outlet box 3, the ball valve 29 is closed, the connected air extraction pump is disconnected, and the flow control valve 9 is closed; during detection, both the box body air outlet pipe 8 and the box body air inlet pipe 7 are connected to the detection instrument. The heating sleeve 4 outside the specified sampling pipe 5 works to heat it. The volatile organic compounds in the sampling pipe 5 start to volatilize. The electromagnetic control valves 24 corresponding to both ends of the sampling pipe 5 are opened. The volatile organic compounds in the sampling pipe 5 are separated from the absorption filler and discharged from the air outlet pipe. The air inlet in the box body inlet pipe 7 will supply air to help the volatilized volatile organic compounds be discharged, thus completing the detection;After the detection is completed, the gas outlet pipeline 8 and the gas inlet pipeline 7 of the box body are separated from the detection instrument, and then the cleaning and purging work can be carried out. All the heating sleeves 4 can be started to heat all the sampling tubes 5, and the electromagnetic control valve 24 on the nitrogen tank 6 is opened for nitrogen purging, so as to purge and discharge all the volatile organic compounds in the sampling tubes 5.

[0058] The above-described embodiments are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and modifications made to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A volatile organic compound sampling device, characterized in that: It includes a storage box body, a pretreatment box body and an extraction pipe. The storage box body, the pretreatment box body and the extraction pipe are connected in sequence. The storage box body includes an air inlet box, a sampling box and an air outlet box. The air outlet box, the sampling box and the air inlet box are stacked and detachably installed and fixed in sequence. There are several heating sleeves in the sampling box, and corresponding sampling pipes are arranged in the heating sleeves. A nitrogen gas tank is also arranged in the sampling box, and the nitrogen gas tank is communicated with the air inlet box. An air inlet conveying channel and an air outlet conveying channel which are hermetically and cooperatively matched with the two ends of the sampling pipe are respectively arranged in the air inlet box and the air outlet box. Each sampling pipe is pressed and fixed through the air outlet box and the air inlet box. Electromagnetic control valves which are convenient to open or close are arranged on the nitrogen gas tank, the air inlet conveying channel and the air outlet conveying channel. The air outlet box has the same structure as the air inlet box. A locking structure is arranged between the air outlet box and the sampling box, and between the air inlet box and the sampling box. An air inlet pipeline of the box body which is convenient for air inlet is arranged on the air inlet box, and an air outlet pipeline of the box body which is convenient for air outlet is arranged on the air outlet box. Flow control valves which can be opened and closed are arranged on the air inlet pipeline of the box body and the air outlet pipeline of the box body. The ends of the air inlet pipeline of the box body and the air outlet pipeline of the box body are both quick-insert structures. The air inlet pipeline of the box body is communicated with the pretreatment box body for preprocessing the sampled gas through the quick-insert structure. The pretreatment box body is connected with a copper extraction pipe through the quick-insert structure. A replacement connecting pipeline with a valve is also connected between the air inlet box and the air outlet box. An air inlet and an air outlet are arranged on the pretreatment box body. Box body air inlet pipelines and box body air outlet pipelines are arranged at the air inlet and the air outlet. The air inlet pipeline of the box body is communicated with the box body air outlet pipeline through the quick-insert structure. Pretreatment valves which are convenient to open and close are arranged on the box body air inlet pipeline and the box body air outlet pipeline. The ends of the box body air inlet pipeline and the box body air outlet pipeline are both quick-insert structures. A pretreatment pipe which is communicated with the air inlet and the air outlet is arranged inside the pretreatment box body. The pretreatment pipe includes a heating part and a condensation part. The heating part is located upstream of the condensation part. A condensate collection port is arranged at the low position of the condensation part, and a condensate collection bottle which is convenient for disassembly and assembly is arranged at the condensate collection port. An extraction pipe is connected to the air outlet pipeline through the quick-insert structure. A handle which is convenient to grasp is rotatably installed on the air inlet box.

2. The volatile organic compound sampling device according to claim 1, wherein: The air inlet box includes an air inlet chamber. A number of air inlet conveying holes are opened on the air inlet chamber. Each air inlet conveying hole is communicated with the air inlet conveying channel in one-to-one correspondence. An upper guiding inclined groove for pressing and sealing the sampling pipe is opened at the lower end of the air inlet conveying channel. The air inlet pipeline of the box body is communicated with the air inlet chamber. The air outlet box includes an air outlet chamber. A number of air outlet conveying holes are opened in the air outlet chamber. Each air outlet conveying hole is communicated with the air outlet conveying channel in one-to-one correspondence. A lower guiding inclined groove for pressing and sealing the sampling pipe is opened at the upper end of the air outlet conveying channel. The air outlet pipeline of the box body is communicated with the air outlet chamber.

3. The volatile organic compound sampling device as described in claim 2, wherein: A purging pipeline which extends into the air inlet chamber is arranged on the nitrogen gas tank, and a quick-insert structure which is convenient for disassembly and assembly is also arranged on the purging pipeline. Elastic gaskets which are in contact with the sampling pipe are arranged on both the upper guiding inclined groove and the lower guiding inclined groove.

4. A volatile organic compound sampling device as described in claim 3, characterized in that: The pre-treatment pipe is a U-shaped pipe. The heating part includes a heating pipe section located on the U-shaped pipe and communicating with the air inlet. A heating wire is provided on the heating pipe section. The condensation part includes a condensation pipe section communicating with the downstream of the heating pipe section. A condensation device for active cooling is provided on the condensation pipe section. A tail pipe section is communicated with the downstream of the condensation pipe section, and the tail pipe section is communicated with the air outlet.

5. A volatile organic compound sampling device as described in claim 4, characterized in that: The condensation pipe section includes a first pipe section and a second pipe section. The position of the first pipe section is higher than that of the second pipe section. The first pipe section and the second pipe section are communicated through a diversion pipe section. Condensation devices are provided on the first pipe section, the second pipe section and the diversion pipe section.

6. A volatile organic compound sampling device as described in claim 5, characterized in that: Both the first pipe section and the second pipe section are vertically installed. The condensate collection port is arranged at the bottom of the second pipe section. The condensate collection port and the condensate collection bottle are fixed by threaded connection.

7. A volatile organic compound sampling device as described in claim 6, characterized in that: The diameter of the heating pipe section is smaller than that of the condensation pipe section.

8. A volatile organic compound sampling device as described in claim 6, characterized in that: The inner wall of the suction pipe is covered with an inert coating through inert treatment.

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