An apparatus for detecting volatile organic compounds in air

Abstract

The application relates to air volatile organic compound content detection equipment and belongs to the volatile organic compound detection field. The equipment comprises a box body, a base and a detection device, the base is fixedly installed at the bottom of the box body, the detection device is arranged in the box body, a shell is fixedly installed on the outer wall of the box body, an electric heating pipe is fixedly connected in the shell, the electric heating pipe is arranged in a snakelike mode and surrounds the outside of the box body. The filter screen and the drying agent arranged at the air inlet end can efficiently filter dust and remove water vapor, PID sensor zero point drift, electrode corrosion and failure in the detection device caused by high humidity environment are avoided, detection data accuracy and long-term stability are significantly improved, the reverse exhaust of the piston drives airflow to flow through the drying agent in a reverse direction, the electric heating pipe is used for heating and drying, the drying agent is automatically regenerated and recycled after water absorption saturation, manual disassembly and replacement are not needed, operation and maintenance cost is reduced, and the equipment is suitable for long-term unattended, random start-stop sampling and inspection scenes.

Description

Technical Field

[0001] This invention relates to the field of volatile organic compound (VOC) detection technology, and particularly to a device for detecting the content of VOCs in air. Background Technology

[0002] Online or spot-check equipment for volatile organic compounds (VOCs) is widely used in fugitive emissions from factories, boundary monitoring, and indoor air quality testing. Currently, most mainstream detection methods employ PID photoionization sensors as the core detection element. These sensors offer advantages such as fast response, high sensitivity, a wide measurable concentration range, and suitability for rapid on-site screening, making them the preferred sensor for industrial VOCs spot-checking.

[0003] PID sensors rely on ultraviolet light sources to ionize organic gases and are extremely sensitive to environmental humidity and dust interference. In high humidity environments, water vapor can easily condense in the sensor cavity, causing electrode corrosion, zero drift, and measurement data distortion. In severe cases, this can lead to sensor failure. Dust adhering to the sensor surface or in the gas path will also reduce detection accuracy and shorten the sensor's lifespan.

[0004] Upon investigation, a Chinese invention patent discloses a volatile organic compound content detection device and method (publication number: CN114414748A), which includes a detection device body and a rinsing tank. An air inlet cylinder is provided on the upper surface of the detection device body, and first rinsing holes are provided at equal intervals on the side of the detection device body near the air inlet cylinder. An air inlet assembly is provided in the detection device body at the lower end of the air inlet cylinder.

[0005] The aforementioned patent uses a detection device that employs piston negative pressure suction and high-pressure nitrogen backflushing for cleaning. However, this device is only equipped with a dust filter to remove particulate matter, lacks a dehumidification structure, and does not have a protective design for the high humidity sensitivity of the PID sensor. It is difficult to remove moisture from the sampled gas. In addition, it relies on external high-pressure nitrogen for pipeline cleaning, resulting in a complex structure and high maintenance costs. It is not suitable for long-term unattended, intermittent sampling inspections in factory areas. Furthermore, most existing detection devices with dehumidification functions use disposable desiccants for dehumidification. Once the desiccant is saturated with water, it needs to be manually disassembled and replaced, making automatic regeneration impossible. This leads to cumbersome operation and maintenance, making it difficult to adapt to the sampling inspection requirements of random start-stop and long-term unattended operation.

[0006] Therefore, this application provides a device for detecting the content of volatile organic compounds in air to meet the requirements. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a device for detecting the content of volatile organic compounds in the air, so as to solve the problems of existing detection devices not having dehumidification protection and inconvenient operation and maintenance.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: An air volatile organic compound (VOC) content detection device includes a housing, a base, and a detection device. The base is fixedly installed at the bottom of the housing, and the detection device is disposed inside the housing. A shell is fixedly installed on the outer wall of the housing, and an electric heating tube is fixedly connected inside the shell. The electric heating tube is arranged in a serpentine shape and surrounds the outside of the housing. A piston block is movably connected inside the housing. A feedback mechanism is provided between the piston block and the electric heating tube. The feedback mechanism is used to provide feedback on the electrical signal of the electric heating tube. The feedback mechanism includes a metal ball, a second spring, symmetrically arranged metal plates, a guide plate, and a third spring. A sealing assembly is provided between the piston block and the detection device. The sealing assembly is used to isolate the detection device. The sealing assembly includes a mounting plate, multiple blocking plates, and a first spring.

[0009] Optionally, a baffle is fixedly connected inside the box, a fixed frame is fixedly connected inside the box, a hydraulic rod is fixedly connected to the fixed frame, the hydraulic rod passes through the baffle, and the output end of the hydraulic rod is fixedly connected to the piston block, and a connecting plate is fixedly connected to the output end of the hydraulic rod.

[0010] Optionally, a connecting rod is fixedly connected to the connecting plate, a sliding rod is fixedly connected to the metal ball, a cylindrical cavity is opened on the connecting rod, the end of the sliding rod is slidably connected in the cylindrical cavity, the second spring is disposed in the cylindrical cavity, and the two ends of the second spring are fixedly connected to the sliding rod and the inner wall of the cylindrical cavity, respectively.

[0011] Optionally, a partition is fixedly connected to the inner wall of the box, and multiple fixing plates are fixedly connected between the metal plate and the partition. One end of the guide plate is rotatably connected to the metal plate, and the other end of the guide plate abuts against the partition.

[0012] Optionally, connecting blocks are symmetrically fixed on the fixing frame, an arc-shaped rod is fixedly connected to the guide plate, and the arc-shaped rod slides through the connecting block. The third spring is sleeved on the arc-shaped rod, and the two ends of the third spring are fixedly connected to the guide plate and the connecting block, respectively.

[0013] Optionally, the detection device is fixedly mounted on the mounting plate, a support frame is fixedly connected to the mounting plate, the piston block has a mounting groove, and the mounting plate is slidably connected in the mounting groove. The blocking plate is rotatably connected to the opening of the mounting groove by a torsion spring.

[0014] Optionally, a round rod is fixedly connected to the bottom of the mounting plate, and the round rod slides through the bottom of the mounting groove. A round plate is fixedly connected to the bottom of the round rod. The first spring is sleeved on the round rod, and the two ends of the first spring are fixedly connected to the round plate and the bottom of the piston block, respectively.

[0015] Optionally, an installation pipe is fixedly connected to the top of the housing, an air supply pipe is provided above the installation pipe, a connecting pipe is bolted between the air supply pipe and the installation pipe, and a desiccant is provided inside the connecting pipe.

[0016] Optionally, a filter screen is fixedly connected to the top of the air supply pipe, an impeller is provided inside the air supply pipe, a mounting bracket is fixedly connected between the filter screen and the air supply pipe, and the impeller is rotatably connected to the mounting bracket.

[0017] Optionally, a connecting frame is rotatably connected to the top of the filter screen, and an mounting rod is coaxially fixed between the impeller and the connecting frame, with the mounting rod passing through the top of the filter screen. A brush plate is fixedly connected to the connecting frame, and the brush plate is in close contact with the outer wall of the filter screen.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects: In the above solution, by setting a filter and desiccant at the air inlet, dust and moisture can be effectively filtered out, avoiding zero drift, electrode corrosion and failure of the PID sensor in the detection device caused by high humidity environment. This significantly improves the accuracy and long-term stability of the detection data. The reverse exhaust of the piston drives the airflow to flow in the opposite direction through the desiccant, and the electric heating tube heats and dries it. After the desiccant is saturated with water, it is automatically regenerated and recycled. There is no need for manual disassembly and replacement, which reduces the operation and maintenance cost and is suitable for long-term unattended operation and random start-stop sampling inspection scenarios.

[0019] By setting up a feedback mechanism to feed back electrical signals to the electric heating tube, when the piston block moves down to draw in gas, the metal ball contacts the partition plate. When the piston block moves backward to discharge gas, the metal block moves between the two metal plates under the action of the guide plate, so that the circuit of the electric heating tube is closed. The desiccant is dried by heating the airflow, realizing the regeneration of the desiccant without frequent replacement, thereby improving the convenience of equipment operation and maintenance.

[0020] By setting up a sealing component, the detection device can be automatically sealed during the desiccant regeneration process, preventing damage to the sensor from the high-temperature airflow. At the same time, it ensures that the heating and drying only acts on the desiccant area, improving regeneration efficiency, avoiding the impact of high temperature on other parts of the equipment, and ensuring the overall operational stability of the equipment. With the coordinated operation of various functional components, the desiccant regeneration and filter cleaning can be automatically completed after one round of sampling and testing. It can automatically prepare for the next test without manual intervention, fully meeting the needs of long-term unattended fixed-point intermittent sampling inspection in the factory area. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a device for detecting the content of volatile organic compounds in air. Figure 2 This is a cross-sectional view of the structure of a device for detecting the content of volatile organic compounds in air; Figure 3 for Figure 2 A magnified view of a portion of the image; Figure 4 for Figure 3 Enlarged view of point A in the middle; Figure 5 This is a structural exploded view of a device for detecting the content of volatile organic compounds in air. Figure 6 This is a schematic diagram of the structure of an electric heating tube in an air volatile organic compound (VOC) content detection device. Figure 7 This is a schematic diagram of the structure of a blockage in an air volatile organic compound (VOC) content detection device. Figure 8 This is a schematic diagram of the structure of a metal plate in an air volatile organic compound (VOC) content detection device.

[0022] Figure label: 1. Housing; 2. Base; 3. Mounting pipe; 4. Shell; 5. Air supply pipe; 6. Filter screen; 7. Piston block; 8. Hydraulic rod; 9. Baffle; 10. Connecting pipe; 11. Desiccant; 12. Electric heating element; 13. Impeller; 14. Mounting bracket; 15. Mounting rod; 16. Connecting bracket; 17. Brush plate; 18. Blocking plate; 19. Connecting plate; 20. Fixing bracket; 21. Mounting plate; 22. Support frame; 23. Round rod; 24. First spring; 25. Round plate; 26. Connecting rod; 27. Slide rod; 28. Second spring; 29. ​​Metal ball; 30. Partition plate; 31. Metal plate; 32. Fixing plate; 33. Guide plate; 34. Connecting block; 35. Arc rod; 36. Third spring; 37. Detection device. Detailed Implementation

[0023] To further illustrate the technical means and effects adopted by the present invention in order to achieve the intended purpose, the following detailed description is provided in conjunction with the accompanying drawings and preferred embodiments, based on the specific implementation methods, structures, features and effects of the present invention.

[0024] like Figures 1 to 8As shown, an embodiment of the present invention provides a device for detecting the content of volatile organic compounds in air, including a housing 1, a base 2, and a detection device 37. The base 2 is fixedly installed at the bottom of the housing 1, and the detection device 37 is disposed inside the housing 1. A housing 4 is fixedly installed on the outer wall of the housing 1, and an electric heating tube 12 is fixedly connected inside the housing 4. The electric heating tube 12 is arranged in a serpentine shape and surrounds the outside of the housing 1. A piston block 7 is movably connected inside the housing 1. A feedback mechanism is provided between the piston block 7 and the electric heating tube 12. The feedback mechanism is used to feed back the electrical signal of the electric heating tube 12. The feedback mechanism includes a metal ball 29, a second spring 28, symmetrically arranged metal plates 31, a guide plate 33, and a third spring 36. By setting the feedback mechanism, the electrical signal is fed back to the electric heating tube 12. When the piston block 7 moves down to draw in gas, the metal ball 29 contacts the partition plate 30. When the piston block 7 moves backward to discharge gas, the metal ball 29 contacts the two metal plates 38 under the action of the guide plate 33. When the plate 31 contacts the desiccant 12, the circuit of the electric heating tube 12 is closed, and the desiccant 11 is dried by the heated airflow, thus regenerating the desiccant 11 without frequent replacement, thereby improving the convenience of equipment operation and maintenance. The linkage feedback mechanism can automatically switch the electric heating tube 12 on and off with the movement of the piston block 7, triggering heating only during the reverse exhaust phase, accurately matching the regeneration sequence of the desiccant 11, reducing ineffective energy consumption, and ensuring that heating only acts on the regeneration process, avoiding thermal impact on the sensor. A sealing component is provided between the piston block 7 and the detection device 37. The sealing component is used to isolate the detection device 37. The sealing component includes a mounting plate 21, multiple blocking plates 18 and a first spring 24. By setting the sealing component, the detection device 37 can be automatically sealed during the regeneration of the desiccant 11, preventing high-temperature airflow from damaging the sensor, while ensuring that heating and drying only act on the desiccant 11 area, improving regeneration efficiency, avoiding the impact of high temperature on other parts of the equipment, and ensuring the overall operational stability of the equipment.

[0025] like Figure 2 and Figure 3 As shown, a baffle 9 is fixedly connected inside the housing 1, and a fixed frame 20 is also fixedly connected inside the housing 1. A hydraulic rod 8 is fixedly connected to the fixed frame 20. The hydraulic rod 8 passes through the baffle 9, and its output end is fixedly connected to the piston block 7. A connecting plate 19 is fixedly connected to the output end of the hydraulic rod 8. When sampling and testing are required, the hydraulic rod 8 pushes the piston block 7 downward, creating a negative pressure inside the housing 1. This draws outside air into the housing 1 through the air supply pipe 5, connecting pipe 10, and installation pipe 3. After the air passes through the filter screen 6 to remove large dust particles, it passes through the desiccant 11 to remove moisture from the air. After pretreatment, the air enters the housing 1 and is pushed into the detection end. The detection device 37 then performs content detection. The negative pressure suction combined with the two-stage pre-purification effectively removes dust and moisture, protects the PID sensor from contamination and corrosion, and ensures stable and reliable detection data. The hydraulic drive stroke is controllable, the thrust is uniform, and it is suitable for long-term intermittent start-stop conditions. It operates smoothly and has a low failure rate.

[0026] like Figure 5 and Figure 8 As shown, a connecting rod 26 is fixedly connected to the connecting plate 19, and a sliding rod 27 is fixedly connected to the metal ball 29. A cylindrical cavity is opened on the connecting rod 26, and the end of the sliding rod 27 is slidably connected to the cylindrical cavity. A second spring 28 is set in the cylindrical cavity, and the two ends of the second spring 28 are fixedly connected to the sliding rod 27 and the inner wall of the cylindrical cavity, respectively. A partition 30 is fixedly connected to the inner wall of the box 1. Multiple fixing plates 32 are fixedly connected between the metal plate 31 and the partition 30. One end of the guide plate 33 is rotatably connected to the metal plate 31, and the other end of the guide plate 33 abuts against the partition 30. A connecting block 34 is symmetrically fixed on the fixing frame 20. An arc rod 35 is fixedly connected to the guide plate 33, and the arc rod 35 slides through the connecting block 34. A third spring 36 is sleeved on the arc rod 35, and the two ends of the third spring 36 are fixedly connected to the guide plate 33 and the connecting block 34, respectively.

[0027] During use, the metal ball 29 moves downward with the piston block 7. At this time, the circuit of the electric heating tube 12 is disconnected and it will not heat. As the metal ball 29 moves downward to the lowest end of the partition 30, it passes through the guide plate 33. After the test is completed, when the metal ball 29 moves upward with the piston block 7, under the guidance of the guide plate 33, the metal ball 29 drives the slide rod 27 to retract into the connecting rod 26 and compresses the second spring 28, so that the metal ball 29 contacts the two metal plates 31, turning on the circuit of the electric heating tube 12. The electric heating tube 12 is then energized and heated, thus drying. The water vapor adsorbed by the desiccant 11 evaporates and is discharged from the equipment with the reverse airflow, completing the automatic regeneration of the desiccant 11 without manual replacement. The electric heating tube 12 starts automatically, realizing automatic linkage of the regeneration process without additional control. The metal ball 29 and the metal plate 31 form a contact switch, which is reliable and responsive. The second spring 28 and the third spring 36 provide reset and buffer, ensuring stable contact and smooth rebound, avoiding poor connection or jamming. The serpentine electric heating tube 12 heats evenly, has high thermal efficiency, and works stably, drying thoroughly without damaging the desiccant 11.

[0028] like Figure 5 and Figure 7 As shown, the detection device 37 is fixedly installed on the mounting plate 21. A support frame 22 is fixedly connected to the mounting plate 21. The piston block 7 has an installation groove, and the mounting plate 21 is slidably connected in the installation groove. The blocking plate 18 is rotatably connected to the opening of the installation groove by a torsion spring. A round rod 23 is fixedly connected to the bottom of the mounting plate 21, and the round rod 23 slides through the bottom of the installation groove. A round plate 25 is fixedly connected to the bottom of the round rod 23. A first spring 24 is sleeved on the round rod 23, and the two ends of the first spring 24 are fixedly connected to the round plate 25 and the bottom of the piston block 7, respectively.

[0029] When in use, the piston block 7 moves downward, and the circular plate 25 first contacts the baffle 9. Under the obstruction and compression of the baffle 9, the first spring 24 is compressed, causing the detection device 37 to move out of the mounting slot. At the same time, the support frame 22 pushes the blocking plate 18 to overcome the torsional force of the torsion spring and open it. The removed detection device 37 performs detection work on the dry gas entering the housing 1. The piston block 7 pushes the gas in the housing 1 to flow in the reverse direction through the desiccant 11 and outward. When the piston block 7 moves upward, the circular plate 25 loses the compression of the baffle 9 and, under the elastic force of the first spring 24, causes the mounting plate 21 to move downward, so that the detection device 37... The device is moved into the mounting slot, and the blocking plate 18 rotates under the reset action of the torsion spring to seal the opening of the mounting slot, thus sealing the detection device 37 inside the mounting slot. This prevents the high-temperature airflow from damaging the PID sensor in the detection device 37 and ensures the overall operational stability of the equipment. The detection device 37 can automatically extend and retract with the piston stroke, extending during detection and retracting during regeneration. The actions are synchronized and the response is timely. The blocking plate 18 closes quickly to form a sealed isolation chamber, effectively blocking the high-temperature hot air and protecting the PID sensor from high-temperature impact. The first spring 24 provides flexible reset, reducing mechanical impact and extending the service life of the sensor and moving parts.

[0030] like Figures 2 to 4 As shown, an installation pipe 3 is fixedly connected to the top of the housing 1. An air supply pipe 5 is provided above the installation pipe 3. A connecting pipe 10 is bolted between the air supply pipe 5 and the installation pipe 3. A desiccant 11 is provided inside the connecting pipe 10. A filter screen 6 is fixedly connected to the top of the air supply pipe 5. An impeller 13 is provided inside the air supply pipe 5. A mounting bracket 14 is fixedly connected between the filter screen 6 and the air supply pipe 5. The impeller 13 is rotatably connected to the mounting bracket 14. A connecting bracket 16 is rotatably connected to the top of the filter screen 6. An installation rod 15 is coaxially fixed between the impeller 13 and the connecting bracket 16. The installation rod 15 passes through the top of the filter screen 6. A brush plate 17 is fixedly connected to the connecting bracket 16. The brush plate 17 is in close contact with the outer wall of the filter screen 6.

[0031] During intake sampling, the airflow through the air supply pipe 5 drives the impeller 13 to rotate. The impeller 13, via the mounting rod 15, drives the brush plate 17 on the connecting frame 16 to rotate. The brush plate 17 automatically scrapes away the dust adhering to the surface of the filter screen 6, preventing the filter screen 6 from clogging. During exhaust, the impeller 13 can also rotate, driving the brush plate 17 to scrape away the accumulated dust adhering to the filter screen 6. The exhaust gas can also blow away the dust on the filter screen 6, achieving automatic cleaning of the filter screen 6 without the need for manual cleaning, further reducing the frequency of maintenance. With the coordinated operation of various functional components, a complete cycle is achieved. After sampling and testing, the desiccant 11 can be regenerated and the filter 6 can be cleaned automatically without manual intervention, which can automatically prepare for the next test. This fully meets the needs of long-term unattended fixed-point intermittent sampling inspection in the factory. The filter 6 is made of high-precision PTFE material, which has high dust prevention efficiency and good air permeability. The impeller 13 is driven by airflow and does not require additional power. Both the intake and exhaust can drive the brush plate 17 to rotate, continuously cleaning the surface of the filter 6 and preventing dust accumulation from causing air passage blockage. The connecting pipe 10 is designed to be detachable, which facilitates the filling and replacement of the desiccant 11 and makes maintenance convenient.

[0032] It should be noted that the desiccant 11 is a regenerable desiccant, such as blue color-changing silica gel granules. It can not only efficiently remove moisture from the sampled air and protect the PID sensor from high humidity drift and corrosion, but also visually indicate the saturation state through color. Together with the electric heating tube 12, it can realize in-situ hot air regeneration and recycling without manual disassembly and replacement. It is suitable for the operation requirements of fixed-point intermittent sampling and long-term unattended operation in the factory area. The selection of desiccant 11 adopts the existing technology in this field, so it will not be described in detail.

[0033] The working principle of the technical solution provided by this invention is as follows: When sampling is required during the operation of this equipment, the hydraulic rod 8 drives the piston block 7 to move down. At this time, a negative pressure is formed in the housing 1. After the outside air is filtered by the filter screen 6 to remove dust, it enters the air supply pipe 5. The airflow drives the impeller 13 to rotate, which drives the connecting frame 16 and the brush plate 17 to rotate through the mounting rod 15. The brush plate 17 rotates close to the outer wall of the filter screen 6, automatically scraping off the dust attached to the filter screen 6, avoiding the filter screen 6 from clogging, and completing the automatic cleaning during air intake.

[0034] In addition, the filtered air flows through the desiccant 11 in the connecting pipe 10, adsorbing and removing moisture from the gas. The dry and clean gas enters the housing 1 through the installation pipe 3. As the piston block 7 continues to move down, the circular plate 25 is blocked and squeezed by the baffle 9, compressing the first spring 24 and driving the detection device 37 to move out of the installation slot. The blocking plate 18, pushed by the support frame 22, overcomes the torsional force of the torsion spring and is in an open state. The removed detection device 37 performs detection work on the dry gas entering the housing 1. At this time, the metal ball 29 moves down with the piston block 7. During the downward movement, it is always in contact with the partition 30. At this time, the circuit of the electric heating tube 12 is in an open state and will not heat up. During the process of moving down to the lowest end of the partition 30, the metal ball 29 pushes the guide plate 33 to rotate, causing the guide plate 33 to compress the third spring 36. When the metal ball 29 separates from the guide plate 33, the compressed third spring 36 resets and pushes the guide plate 33 to reset.

[0035] Furthermore, after completing one test, the hydraulic rod 8 drives the piston block 7 to move upward. The piston block 7 pushes the gas in the housing 1 to flow in the opposite direction through the desiccant 11 and outward. As the piston block 7 moves upward, the circular plate 25 loses the pressure of the baffle 9 and, under the elastic force of the first spring 24, drives the mounting plate 21 to move downward, so that the detection device 37 moves into the mounting groove. The support frame 22 on the mounting plate 21 no longer presses the blocking plate 18. At this time, the blocking plate 18 rotates under the reset action of the torsion spring, and the blocking plate 18 seals the opening of the mounting groove, sealing the detection device 37 in the mounting groove.

[0036] Furthermore, the metal ball 29 moves upward with the piston block 7 and contacts the guide plate 33 during the movement. Under the guidance of the guide plate 33, the metal ball 29 drives the slide rod 27 to retract into the connecting rod 26 and compresses the second spring 28, so that the metal ball 29 contacts the two metal plates 31, which turns on the circuit of the electric heating tube 12. The electric heating tube 12 is energized, and the gas flowing in the opposite direction is heated when it passes through the electric heating tube 12. The hot gas passes through the desiccant 11 and carries away the water vapor adsorbed by the desiccant 11, realizing the heating, drying and regeneration of the desiccant 11, which is convenient for the next test. The whole process does not require manual replacement of the desiccant 11. At the same time, the exhaust hot gas can also drive the impeller 13 to rotate, which drives the connecting frame 16 and the brush plate 17 to rotate through the mounting rod 15, automatically scraping off the dust attached to the filter screen 6. The exhaust gas blows away the dust on the filter screen 6, completing the cleaning of the filter screen 6 during exhaust. In this way, the entire process of automatic sampling, detection, desiccant 11 regeneration and filter screen 6 cleaning can be completed.

[0037] Furthermore, when the piston block 7 is moved to its initial position, the metal ball 29 moves away from the metal plate 31. The compressed second spring 28 drives the slide rod 27 and the metal ball 29 to reset, so that they re-contact the partition 30. At this time, the circuit of the electric heating tube 12 is disconnected, and heating stops, so as to prevent the electric heating tube 12 from continuing to heat when the equipment is not working, which would cause energy waste and damage to the equipment.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A device for detecting the content of volatile organic compounds in air, characterized in that, The device includes a housing (1), a base (2), and a detection device (37). The base (2) is fixedly installed at the bottom of the housing (1). The detection device (37) is located inside the housing (1). A shell (4) is fixedly installed on the outer wall of the housing (1). An electric heating tube (12) is fixedly connected inside the shell (4). The electric heating tube (12) is arranged in a serpentine shape and surrounds the outside of the housing (1). A piston block (7) is movably connected inside the housing (1). A feedback mechanism is provided between the piston block (7) and the electric heating tube (12). The feedback mechanism automatically switches the circuit of the electric heating tube (12) on and off as the piston block (7) moves. The feedback mechanism includes a metal ball (29), a second spring (28), a symmetrically arranged metal plate (31), a guide plate (33), and a third spring (36). A sealing assembly is provided between the piston block (7) and the detection device (37). The sealing assembly is used to seal and isolate the detection device (37). The sealing assembly includes a mounting plate (21), multiple blocking plates (18) and a first spring (24). A baffle (9) is fixedly connected inside the box (1), a fixed frame (20) is fixedly connected inside the box (1), a hydraulic rod (8) is fixedly connected on the fixed frame (20), the hydraulic rod (8) passes through the baffle (9), and the output end of the hydraulic rod (8) is fixedly connected to the piston block (7), and a connecting plate (19) is fixedly connected on the output end of the hydraulic rod (8). A connecting rod (26) is fixedly connected to the connecting plate (19), and a sliding rod (27) is fixedly connected to the metal ball (29). A cylindrical cavity is opened on the connecting rod (26), and the end of the sliding rod (27) is slidably connected in the cylindrical cavity. The second spring (28) is set in the cylindrical cavity, and the two ends of the second spring (28) are fixedly connected to the sliding rod (27) and the inner wall of the cylindrical cavity, respectively. A partition (30) is fixedly connected to the inner wall of the box (1), and a plurality of fixed plates (32) are fixedly connected between the metal plate (31) and the partition (30). One end of the guide plate (33) is rotatably connected to the metal plate (31), and the other end of the guide plate (33) abuts against the partition (30). The fixing frame (20) is symmetrically fixed with connecting blocks (34), the guide plate (33) is fixedly connected with an arc rod (35), and the arc rod (35) slides through the connecting block (34). The third spring (36) is sleeved on the arc rod (35), and the two ends of the third spring (36) are fixedly connected to the guide plate (33) and the connecting block (34) respectively. The detection device (37) is fixedly installed on the mounting plate (21), and a support frame (22) is fixedly connected to the mounting plate (21). The piston block (7) has an installation groove, and the mounting plate (21) is slidably connected in the installation groove. The blocking plate (18) is rotatably connected to the opening of the installation groove by a torsion spring. The bottom of the mounting plate (21) is fixedly connected to a round rod (23), and the round rod (23) slides through the bottom of the mounting groove. The bottom of the round rod (23) is fixedly connected to a round plate (25). The first spring (24) is sleeved on the round rod (23), and the two ends of the first spring (24) are fixedly connected to the bottom of the round plate (25) and the piston block (7) respectively.

2. The air volatile organic compound content detection device according to claim 1, characterized in that, The top of the box (1) is fixedly connected to an installation pipe (3), and an air supply pipe (5) is provided above the installation pipe (3). A connecting pipe (10) is bolted between the air supply pipe (5) and the installation pipe (3), and a desiccant (11) is provided inside the connecting pipe (10).

3. The air volatile organic compound content detection device according to claim 2, characterized in that, A filter screen (6) is fixedly connected to the top of the air supply pipe (5). An impeller (13) is provided inside the air supply pipe (5). A mounting bracket (14) is fixedly connected between the filter screen (6) and the air supply pipe (5), and the impeller (13) is rotatably connected to the mounting bracket (14).

4. The air volatile organic compound content detection device according to claim 3, characterized in that, The top of the filter screen (6) is rotatably connected to a connecting frame (16), and an mounting rod (15) is coaxially fixed between the impeller (13) and the connecting frame (16), and the mounting rod (15) passes through the top of the filter screen (6). A brush plate (17) is fixedly connected to the connecting frame (16), and the brush plate (17) is in close contact with the outer wall of the filter screen (6).

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