Photoionization detection device with sampling, sweeping and double-dehumidification functions

Abstract

The utility model relates to the technical field of gas detection, in particular to a photoionization detection device with sampling, sweeping and double dehumidification functions, which comprises a sampling filter, a dehumidification device, a sweeping filter and a photoion gas detector. The sampling filter is located at the foremost end of the device and connected with the dehumidification device, the dehumidification device is connected with the filter adapter through the communicating pipe, the upper portion of the filter adapter is communicated with the optical ion gas detector, the lower portion of the filter adapter is connected with the cleaning filter, the communicating pipe is provided with a three-way connector, and the three-way connector is connected with the dehumidification device. A three-way electromagnetic valve is installed at the three-way connector and connected with an air inlet pipe through the three-way connector, and the air inlet pipe is connected with an air inlet in the bottom of the cleaning filter. According to the utility model, on the basis of dehumidifying the gas sample to be detected, the sweeping gas is also dehumidified, so that the sampling and sweeping dual-dehumidification function is realized, and the positive effects of reducing the false alarm rate of the photoion gas detector and improving the detection accuracy are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of gas detection, in particular to a photoionization detection device with sampling, cleaning and double dehumidification functions. Background Art

[0002] With the development of industry, various new materials and products have been invented, but more and more toxic and harmful substances have also been produced incidentally, and volatile organic compounds (VOC) are one of them. Therefore, it is necessary to detect volatile organic compounds, such as detecting the volatile organic compounds contained in a specific environment to determine the safety level of the environment.

[0003] A photoionization gas detector is a commonly used device for detecting volatile organic compound gases. The concentration of volatile organic compounds in the gas to be detected is calculated by ionizing the gas to be detected and measuring the current intensity value generated by the ionized gas. However, when the water vapor content in the gas to be detected is too high, it will seriously affect the sensitivity of the photoionization gas detector. Therefore, when using the photoionization gas detector for detection, the gas to be detected needs to be dehumidified. In the Chinese utility model patents previously applied by the applicant: "CN 218567041 U A photoionization detection device with dehumidification function" and "CN 218567040U "A dehumidifier for a detection device" introduces the dehumidification function of the photoionization gas detector in detail. However, in actual use, the photoionization gas detector also has a cleaning function. The VOC in the environment is removed by cleaning the filter to obtain clean air, thereby cleaning the gas path of the photoionization gas detector to avoid errors caused by residual gas during re-detection, making the detection result more accurate. However, in the cleaning process, the water vapor in the air is not effectively removed, so that the photoionization detector has a false alarm due to the residual water vapor in the cleaning air, affecting the accuracy of the detection.

[0004] Therefore, a photoionization detection device that can dehumidify the purge gas based on the existing technology is a problem that needs to be solved. Utility Model Content

[0005] The purpose of the utility model is to address the deficiencies of the above-mentioned prior art and to provide a photoionization detection device with sampling, cleaning and dual dehumidification functions, so as to achieve the purpose of dehumidifying the cleaned air while maintaining the existing dehumidification of the air to be tested, so as to reduce the false alarm rate of detection and improve the detection accuracy.

[0006] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a photoionization detection device with dual dehumidification functions of sampling and cleaning, including a dehumidification device, which is connected to one side of a filter adapter, the top of the filter adapter is connected to the photoionization gas detector, and the bottom of the filter adapter is connected to the cleaning filter, and an exhaust port is provided at the other end of the filter adapter. It is characterized in that: the dehumidification device is connected to the filter adapter through a connecting pipe, a three-way interface is provided on the connecting pipe, the three-way interface is connected to the air intake pipe, the air intake pipe is connected to the air intake at the bottom of the cleaning filter, and a three-way solenoid valve is installed at the three-way interface.

[0007] Furthermore, the front end of the dehumidification device is connected to a sampling filter.

[0008] Furthermore, the sampling filter is provided with a first cover body, the upper part of the first cover body is connected to the dehumidification device, the lower part of the first cover body is connected to the first cylinder body, a sampling port is provided at the lower part of the first cylinder body, and a dust removal and drying filter element is loaded in the first cylinder body.

[0009] Furthermore, the dehumidification device includes a second cover body, in which a nafion tube is arranged, the front end of the nafion tube is connected to the sampling filter, and the end of the nafion tube is connected to the connecting pipe; the second cover body is connected to the second cylinder body below, the second cylinder body is filled with desiccant, and a drain outlet is arranged below the second cylinder body.

[0010] Furthermore, the cleaning filter is filled with activated carbon.

[0011] The beneficial effects of the utility model are as follows: on the basis of dehumidifying the gas sample to be tested, the sweeping gas is also dehumidified, realizing the dual dehumidification functions of sampling and sweeping, which plays a positive role in reducing the false alarm rate of the photoionization gas detector and improving the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0013] Figure 2 It is a schematic diagram of the main structure of the utility model.

[0014] The names corresponding to the marks in the figure are:

[0015] 1. Sampling filter; 11. First cover body; 12. First cylinder body; 121. Sampling port; 2. Dehumidification device; 21. Second cover body; 211. Connecting pipe; 22. Second cylinder body; 221. Drain port; 3. Cleaning filter; 31. Air inlet; 311. Air inlet pipe; 4. Photoionization gas detector; 5. Three-way interface; 51. Three-way solenoid valve; 6. Exhaust port; 7. Filter adapter. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the utility model.

[0017] Embodiments of the present utility model:

[0018] like Figure 1-2 As shown, in this embodiment, a sampling filter 1 is provided, the sampling filter 1 is connected to the dehumidification device 2, the dehumidification device 2 is connected to the filter adapter 7 through a connecting pipe 211, the filter adapter 7 is connected to the photoionization gas detector 4, an exhaust port 6 is provided on the other side of the filter adapter 7, the connecting pipe 211 is connected to the exhaust port 6 through the photoionization gas detector 4, a cleaning filter 3 is provided below the filter adapter 7, the cleaning filter 3 is threadedly sealed with the filter adapter 7, an air inlet 31 is provided below the cleaning filter 3, the air inlet 31 is connected to the air inlet pipe 311, a three-way interface 5 is provided on the connecting pipe 211, and the three-way interface 5 is connected to the air inlet pipe 311.

[0019] A first cover body 11 is provided in the sampling filter 1, and the bottom of the first cover body 11 is threadedly sealed with the first cylinder body 12, and a sampling port 121 is provided at the bottom of the first cylinder body 12, wherein the first cylinder body 12 is filled with a filter dust removal filter element, which may be a coarse filter screen, filter paper, a desiccant (anhydrous MgCl2, etc.), filter paper, etc. in sequence; dust removal and removal of most of the water can be achieved.

[0020] The first cover body 11 of the sampling filter 1 is connected to the second cover body 21 of the dehumidification device 2, and the second cover body 21 is threadedly sealed with the second cylinder body 22. A nafion tube (existing) for dehumidification is arranged in the second cover body 21, and the sample gas is discharged from the connecting pipe 211 on the other side of the second cover body 21 through the nafion tube. The second cylinder body 22 is filled with a desiccant to absorb the moisture precipitated from the nafion tube. A drain port 221 is arranged at the bottom of the second cylinder body 22, and a valve is provided at the drain port 221. If moisture is generated in the second cylinder body 22, the moisture can be discharged.

[0021] The filter adapter 7 is fixedly connected to the photoionization gas detector 4, and the bottom of the filter adapter 7 is threadedly sealed to the cleaning filter 3, and the cleaning filter 3 is filled with activated carbon for removing VOC in the environment.

[0022] The principle of this utility model is:

[0023] The gas to be tested enters from the sampling port 121, and dust and impurities are removed by the sampling filter 1. The humidity of the sampled gas is reduced by the dehumidification device 2, and then the gas goes to the photoionization gas detector 4 to detect the VOC in the gas. After the gas is detected, it is discharged from the exhaust port 6; in the present utility model, the sampling filter 1 and the dehumidification device 2 are involved. As described in the background technology, the sampling filter 1 and the dehumidification device 2 have been disclosed by the applicant and belong to the prior art. The structure and principle thereof are not difficult to be understood by those skilled in the art, and will not be described in detail.

[0024] When the photoionization gas detector 4 performs self-cleaning work, the three-way solenoid valve 51 connects the dehumidification device 2 with the bottom of the cleaning filter 3, and the air enters the cleaning filter 3 from the bottom of the cleaning filter 3 through the sampling filter 1 and the dehumidification device 2 via the air inlet pipe 311 (the cleaning filter 3 and the filter adapter 7 are also prior art), thereby dehumidifying the cleaning air and removing various organic volatiles and impurities in the sampled gas through the cleaning filter 3, converting the sample gas into clean air, and then the clean air is used to purge and clean the gas path of the detector, thereby achieving the purpose of self-cleaning.

[0025] In the utility model, the sampling and cleaning gas path switching of the photoionization gas detector 4 is controlled by the three-way solenoid valve 51 at the three-way interface 5 (not shown in the figure, but it is not difficult for technical personnel in this field to understand), and the sampling and cleaning work in a cycle. The photoionization gas detector 4 is a built-in pump suction type. After reducing the humidity through the device of the utility model, the false alarm rate caused by water vapor can be reduced by more than 95%, making the photoionization gas detector 4 more accurate.

Claims

1. A photoionization detection device with sampling and cleaning dual dehumidification functions, comprising a dehumidification device (2), the dehumidification device (2) being connected to one side of a filter adapter (7), the filter adapter (7) being connected to a photoionization gas detector (4) at the top, and being connected to a cleaning filter (3) at the bottom, and an exhaust port (6) being provided at the other end of the filter adapter (7), characterized in that: The dehumidification device (2) is connected to the filter adapter (7) via a connecting pipe (211), a three-way interface (5) is provided on the connecting pipe (211), the three-way interface (5) is connected to an air intake pipe (311), the air intake pipe (311) is connected to an air intake port (31) at the bottom of the cleaning filter (3), and a three-way solenoid valve (51) is installed at the three-way interface (5).

2. The photoionization detection device with sampling, cleaning and dual dehumidification functions according to claim 1 is characterized in that: The front end of the dehumidification device (2) is connected to the sampling filter (1).

3. The photoionization detection device with sampling, cleaning and dual dehumidification functions according to claim 2 is characterized in that: The sampling filter (1) is provided with a first cover body (11), the top of the first cover body (11) is connected to the dehumidification device (2), the bottom of the first cover body (11) is connected to the first cylinder (12), a sampling port (121) is provided at the bottom of the first cylinder (12), and a dust removal and drying filter element is loaded in the first cylinder (12).

4. The photoionization detection device with sampling, cleaning and dual dehumidification functions according to claim 3 is characterized in that: The dehumidification device (2) comprises a second cover body (21), a nafion tube is arranged in the second cover body (21), the front end of the nafion tube is connected to the sampling filter (1), and the end of the nafion tube is connected to the connecting pipe (211); the second cover body (21) is connected to the second cylinder (22) below, the second cylinder (22) is filled with a desiccant, and a drain outlet (221) is arranged below the second cylinder (22).

5. The photoionization detection device with sampling, cleaning and dual dehumidification functions according to claim 1 is characterized in that: The cleaning filter (3) is filled with activated carbon.

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