VOCs (Volatile Organic Compounds) sampling device and detection equipment with same

Abstract

The utility model relates to the technical field of VOCs detection, in particular to a VOCs sample introduction device and detection equipment with the VOCs sample introduction device, the VOCs sample introduction device comprises an extraction unit and a heating unit which are connected with each other, the extraction unit comprises a container and a sample introduction pipe movably inserted on the container, and one end of the sample introduction pipe extending into the container is connected with a porous extraction membrane structure; an extraction solvent area for storing a solvent is also arranged in the container, so that at least part of the extraction membrane structure is immersed into the extraction solvent area when the sample introduction pipe moves into the container, and the heating unit is connected with the extraction solvent area to heat low-boiling-point VOCs from the extraction solvent area to volatilize the low-boiling-point VOCs. According to the device, the membrane extraction technology is adopted, so that low-boiling-point VOCs components can be effectively enriched and eluted, and the problem that macromolecules and low-boiling-point components are difficult to recognize in VOCs component detection and recognition is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of VOCs detection, in particular to a VOCs sampling device and detection equipment having the same. Background Art

[0002] Volatile organic compounds (VOCs) in ambient air are crucial trace substances and are important precursors to atmospheric haze and photochemical pollution. Because there are over hundreds of types of VOCs in the atmosphere and the physical and chemical processes they participate in are extremely complex, current monitoring technologies are unable to detect all VOC components.

[0003] At present, common VOCs monitoring technologies mainly focus on highly volatile, small-molecule substances. However, due to their high molecular viscosity, low volatility, and low environmental abundance, VOCs with higher molecular weight often remain in the sampling system of common monitoring equipment or their concentration does not reach the detection limit, which makes their monitoring and identification particularly limited, especially the lack of convenient and economical monitoring methods. However, these semi-volatile and low-volatility VOCs in the atmosphere participate in a large number of reactions, and many components are intermediates and tracers in atmospheric chemical reaction processes. Their effective identification can provide important support for understanding atmospheric reaction mechanisms and mitigating particulate matter pollution. Therefore, how to effectively capture and enrich these low-boiling-point, large-molecule VOCs through effective methods so that they can be identified and monitored using common VOCs detection instruments is a problem that needs to be solved at present. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a VOCs sampling device and a detection device having the same. Through the connected extraction unit and heating unit, membrane extraction technology is adopted to effectively enrich and elute low-boiling-point VOCs components, solving the problem that large molecules and low-boiling-point components are difficult to identify in the detection and identification of VOCs components.

[0005] In the first aspect, the utility model provides a VOCs sampling device, comprising an extraction unit and a heating unit connected to each other, the extraction unit comprising a container and an injection tube movably inserted into the container, one end of the injection tube extending into the container is connected to a porous extraction membrane structure, and an extraction solvent area for storing a solvent is also provided in the container, so that when the injection tube moves into the container, at least part of the extraction membrane structure is immersed in the extraction solvent area, and the heating unit is connected to the extraction solvent area to heat the low-boiling-point VOCs from the extraction solvent area to cause them to volatilize.

[0006] Furthermore, a one-way valve is provided on the container.

[0007] Furthermore, the heating unit includes a heating tube body and a heating wire arranged inside or outside the heating tube body, and the heating wire is connected to a temperature controller.

[0008] Furthermore, the invention also includes a purification unit connected to the heating unit, wherein the purification unit includes a purification tube body and an adsorbent located in the purification tube body.

[0009] Furthermore, the adsorbent includes activated carbon.

[0010] Furthermore, the purification tube body has a purification liquid outlet, and the purification liquid outlet is connected to the extraction solvent area to introduce the purified solvent into the extraction solvent area.

[0011] Furthermore, the extraction membrane structure is composed of multiple layers of VOCs extraction and adsorption membranes connected together.

[0012] Furthermore, the VOCs extraction and adsorption membrane is a fiber-type non-woven fabric with a porous structure, and low-boiling-point VOCs adsorbent particles are stably fixed on the membrane.

[0013] Furthermore, the extraction solvent zone is cylindrical, and the extraction membrane structure is adapted to the inner cavity of the extraction solvent zone.

[0014] In the second aspect, the present invention also provides a detection device, comprising the VOCs sampling device described in any one of the schemes in the first aspect, and also comprising an analysis and detection unit, wherein the heating unit is provided with a sample outlet connected to the analysis and detection unit to provide enriched and volatilized low-boiling-point VOCs to the analysis and detection unit.

[0015] The beneficial effects of the utility model are as follows: the VOCs sampling device and the detection equipment equipped with the same provided by the utility model, through the connected extraction unit and heating unit, adopt membrane extraction technology to effectively enrich and elute low-boiling-point VOCs components, thereby solving the problem that large molecules and low-boiling-point components are difficult to identify in the detection and identification of VOCs components. At the same time, the VOCs sampling device can be used as a pre-processing unit of existing analysis and detection equipment, thereby improving the detection range of conventional VOCs detection equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the structure of a detection device with a VOCs sampling device in a specific embodiment of the present invention;

[0017] Among them: 101, sampling tube; 102, extraction unit; 103, heating unit; 104, purification unit; 105, analysis and detection unit; 201, extraction membrane structure; 202, extraction solvent area; 203, solvent inlet; 204, one-way valve; 301, heating wire; 302, temperature controller; 303, waste liquid port; 304, sample outlet; 401, adsorbent; 402, purification liquid outlet. DETAILED DESCRIPTION

[0018] like Figure 1 As shown, the detection device with a VOCs sampling device provided in this embodiment includes an extraction unit 102, a heating unit 103, a purification unit 104 and an analysis and detection unit 105.

[0019] In this embodiment, the extraction unit 102 specifically includes a container and an inlet tube 101 movably connected to the container. One end of the inlet tube 101 extending into the container is connected to a porous extraction membrane structure 201. The container is also provided with an extraction solvent region 202 for storing solvent, so that when the inlet tube 101 moves into the container, at least a portion of the extraction membrane structure 201 is immersed in the extraction solvent region 202, and the low-molecular VOCs components captured by the extraction membrane are desorbed from the solvent. A one-way valve 204 is also provided on the side wall of the container. Specifically, the extraction membrane structure 201 in this embodiment is composed of multiple layers of VOCs extraction adsorption membrane connected to form a cylindrical piston shape. At the same time, the extraction solvent region 202 is also cylindrical. The VOCs extraction adsorption membrane is a fibrous non-woven fabric with a porous structure, and low-boiling-point VOCs adsorbent particles are stably fixed on the membrane body.

[0020] The heating unit 103 in this embodiment is connected to the extraction solvent area 202 and is used to heat the low-boiling-point VOCs from the extraction solvent area 202 and volatilize them. The heating unit 103 includes a heating tube body and a heating wire 301 disposed outside the heating tube body. The heating wire 301 is connected to a temperature controller 302 to control the temperature of the heating wire 301 so that the low-boiling-point VOCs in the solution from the extraction solvent area 202 are first volatilized and directed to the analysis and detection unit 105 through the sample outlet 304, while the remaining solution is discharged to the purification unit 104 through the waste liquid outlet 303.

[0021] like Figure 1 As shown, the purification unit 104 includes a purification tube body and an adsorbent 401 located in the purification tube body. The adsorbent 401 in this embodiment is specifically activated carbon. In some other embodiments, the adsorbent 401 can also be other adsorbent materials with purification function. The purification tube body has a purification liquid outlet 402, and the purification liquid outlet 402 is connected to the solvent inlet 203 of the extraction solvent area 202 to introduce the purified solvent into the extraction solvent area 202, waiting to be used as the extraction solvent when the next sample is injected, thereby realizing the recycling of the solvent.

[0022] It can be understood that the connection method between the extraction unit 102, the heating unit 103 and the purification unit 104 in the present application can realize the transfer of solution or solvent through pipelines, pumps and valves. For example, if the height of the extraction unit 102 is set to be greater than the heating unit 103, when the valve between the two is opened, the solution in the extraction unit 102 enters the heating unit 103 due to gravity. Similarly, if the height of the heating unit 103 is greater than the purification unit 104, when the valve between the two is opened, the unvolatile solution enters the purification unit 104 due to gravity for purification, and the solvent purified by the purification unit 104 needs to be transported back to the extraction unit 102 through pipelines and valves in combination with an infusion pump.

[0023] It should be noted that the analysis and detection unit 105 described in this application refers to a common VOCs inspection instrument or equipment, which is used to separate and identify adsorbed and enriched sample gas.

[0024] The usage process of this embodiment is as follows:

[0025] The sample enters the entire device through the injection tube 101 and directly enters the inlet of the extraction unit 102. When the airflow passes through, the large molecular VOCs are effectively diffused in the extraction membrane structure 201 and adsorbed in the membrane structure. The rear end of the extraction unit 102 is the solvent of the extraction solvent area 202. According to the principle of like dissolves like, a highly volatile organic solvent is selected as the extractant; after the gas sample enters, the extraction membrane structure 201 can effectively capture low-boiling point VOCs components. Then, as the injection tube 101 pushes the extraction membrane structure 201 into the extraction solvent area 202, the low molecular VOCs components captured by the extraction membrane are desorbed in the solvent, and the sample then enters the heating unit 103;

[0026] The heating unit 103 heats the VOCs by heating the heating wire 301 to volatilize them. The heating temperature is controlled by the temperature controller 302. The VOCs with low boiling points volatilize and enter the analysis and detection unit 105 through the sample outlet 304 for analysis. The VOCs with high boiling points do not volatilize and enter the purification unit 104 through the waste liquid outlet 303.

[0027] The purification unit 104 has an adsorbent 401 (such as activated carbon) built in to purify the volatilized solvent waste liquid. The purified waste liquid circulates into the solvent inlet 203 through the purification liquid outlet 402 and enters the solvent structure of the extraction unit 102, waiting to be used as the extraction solvent for the next injection.

[0028] In addition to the above embodiments, the present invention may also have other implementation methods; any technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present invention.

Claims

1. A VOCs sampling device, characterized in that: The invention comprises an extraction unit (102) and a heating unit (103) connected to each other, wherein the extraction unit (102) comprises a container and an injection tube (101) movably plugged into the container, wherein one end of the injection tube (101) extending into the container is connected to a porous extraction membrane structure (201), and an extraction solvent area (202) for storing a solvent is further provided in the container, so that when the injection tube (101) moves into the container, at least a portion of the extraction membrane structure (201) is immersed in the extraction solvent area (202), and the heating unit (103) is connected to the extraction solvent area (202) to heat low-boiling-point VOCs from the extraction solvent area (202) to volatilize them.

2. The VOCs sampling device according to claim 1, characterized in that: A one-way valve (204) is provided on the container.

3. The VOCs sampling device according to claim 1, characterized in that: The heating unit (103) comprises a heating tube body and a heating wire (301) arranged inside or outside the heating tube body, and a temperature controller (302) is connected to the heating wire (301).

4. The VOCs sampling device according to claim 3, characterized in that: It also includes a purification unit (104) connected to the heating unit (103), wherein the purification unit (104) includes a purification tube body and an adsorbent (401) located in the purification tube body.

5. The VOCs sampling device according to claim 4, characterized in that: The adsorbent (401) includes activated carbon.

6. The VOCs sampling device according to claim 4, characterized in that: The purification tube body has a purification liquid outlet (402), and the purification liquid outlet (402) is connected to the extraction solvent area (202) to introduce the purified solvent into the extraction solvent area (202).

7. The VOCs sampling device according to claim 1, characterized in that: The extraction membrane structure (201) is composed of multiple layers of VOCs extraction and adsorption membranes connected together.

8. The VOCs sampling device according to claim 7, characterized in that: The VOCs extraction and adsorption membrane is a fiber-type non-woven fabric with a porous structure, and low-boiling-point VOCs adsorbent particles are stably fixed on the membrane body.

9. The VOCs sampling device according to claim 1, characterized in that: The extraction solvent zone (202) is cylindrical, and the extraction membrane structure (201) is adapted to the inner cavity of the extraction solvent zone (202).

10. A detection device, characterized in that: The invention comprises a VOCs sampling device according to any one of claims 1 to 9, and further comprises an analysis and detection unit (105), wherein the heating unit (103) is provided with a sample outlet (304) connected to the analysis and detection unit (105) to provide enriched and volatilized low-boiling-point VOCs to the analysis and detection unit (105).

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