VOCs waste gas LEL monitoring device

Abstract

The invention relates to the technical field of waste gas chemical or biological purification, in particular to a VOCs waste gas LEL monitoring device which comprises a device body, the device body at least internally comprises a dehydrator, a dehydrator drain valve, a vortex tube refrigerator and a precision filter, the dehydrator is detachably connected with the vortex tube refrigerator, the dehydrator drain valve is connected with the dehydrator, and the precision filter is connected with the vortex tube refrigerator. The precision filter is connected with the dehydrator at intervals, the dehydrator drain valve is connected with the precision filter at intervals, and the dehydrator drain valve is connected with the vortex tube refrigerator at intervals. The device disclosed by the invention can effectively remove moisture and particulate matters in the sample gas and reduce the maintenance frequency of the detector; meanwhile, stable operation of the LEL monitor is improved through the dehydrator, the dehydrator drain valve, the vortex tube refrigerator and the precision filter, and therefore safe operation of waste gas incinerator equipment such as RTO is effectively guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of chemical or biological purification of waste gas, and in particular to a VOCs waste gas LEL monitoring device. Background Art

[0002] With the continuous acceleration of the industrialization process, waste gas treatment has become an important task in the field of environmental protection. In the process of waste gas treatment, RTO (Regenerative Thermal Oxidizer) technology is widely used. It decomposes harmful substances in organic waste gas through high-temperature oxidation and converts them into harmless carbon dioxide and water vapor. In the process of RTO waste gas treatment, LEL combustible gas concentration monitor plays a vital role. LEL combustible gas concentration monitor can help optimize the operating efficiency of the RTO waste gas treatment system. By real-time monitoring of the combustible gas concentration in the waste gas, the operator can adjust the working parameters of the RTO system according to the monitoring results to achieve the best treatment effect. This can not only improve the efficiency of waste gas treatment, but also reduce energy consumption and operating costs, achieving both economic and environmental benefits.

[0003] In the prior art, the publication number is CN207899209U, the publication date is September 25, 2018, and the name is a VOCs waste gas treatment device, which discloses a cylindrical cavity box, a VOCs adsorption mechanism and a hot air desorption and regeneration mechanism. An air inlet is provided on one side of the cylindrical cavity box, and an air outlet is provided on the top of the cylindrical cavity box. The VOCs adsorption mechanism is arranged in the cylindrical cavity box, and the hot air desorption and regeneration mechanism is connected to the cylindrical cavity box. On the bottom side of the cylindrical cavity box, a fan is provided at the lower part of the VOCs adsorption mechanism.

[0004] Although the above technical solution can effectively improve the adsorption efficiency, increase the calorific value of the exhaust gas, reduce the consumption of supplementary fuel, and facilitate the subsequent processing steps, it cannot effectively remove moisture and particulate matter in the sample gas and reduce the frequency of detector maintenance. Summary of the invention

[0005] The inventors have found through research that the current LEL concentration online monitors can be divided into the following categories according to different detection principles: LEL detectors based on the FTA principle, LEL detectors based on the FID principle, and LEL detectors based on the infrared principle. Among them, the LEL detectors based on the FTA principle and the LEL detectors based on the FID principle generally use electric heating to preheat the sample gas to above 100°C during operation, which can effectively prevent the sample gas condensation from affecting the detector, and its stability is relatively high. However, the FTA principle LEL detector and the FID principle LEL detector are less used in actual applications due to their relatively high prices. The infrared principle LEL detection has a relatively low price, and the equipment performance and stability are good, but it requires a relatively low intake sample gas temperature, generally not greater than 50°C. Therefore, when the water vapor content in the sample gas is high, the sample gas will produce small droplets in the detector, causing failure of the LEL detector and greatly affecting the detection results. At present, the sampling and pretreatment systems of most infrared-based LEL detectors use precision filters to pretreat the moisture and particulate matter in the sample gas. However, when the moisture and particulate matter content in the sample gas is high, the precision filter will often be blocked, causing frequent failures of the detector, which has a great impact on the detection results of the sample gas and has a certain impact on the safety of waste gas incinerator equipment such as RTO.

[0006] Based on the above, the purpose of this application is to provide a VOCs waste gas LEL monitoring device, which solves the technical problem that the prior art cannot provide a monitoring device that can effectively remove moisture and particulate matter in the sample gas while reducing the maintenance frequency of the detector by linearly connecting a dehydrator, a dehydrator drain valve, a vortex tube cooler and a precision filter.

[0007] According to one aspect of the present application, a VOCs waste gas LEL monitoring device is provided, including a device body, wherein the device body includes at least a dehydrator, a dehydrator drain valve, a vortex tube refrigerator and a precision filter, the dehydrator is detachably connected to the vortex tube refrigerator, the dehydrator drain valve is connected to the dehydrator, the precision filter is spaced apart from the dehydrator, the dehydrator drain valve is spaced apart from the precision filter, and the dehydrator drain valve is spaced apart from the vortex tube refrigerator.

[0008] In some embodiments, the drift eliminator comprises a heat exchange coil.

[0009] In some embodiments, the air inlet pipe of the water eliminator is connected to the exhaust pipe, and the air outlet pipe of the water eliminator is connected to the precision filter via a connection sample gas cut-off valve.

[0010] In some embodiments, the dewatering device drain valve is connected to the dewatering device through a water storage pipe.

[0011] In some embodiments, the vortex tube refrigerator is connected to the heat exchange coil via a capillary tube.

[0012] In some embodiments, the precision filter is connected to an LEL online monitor, and the air outlet pipe of the precision filter is connected to the air inlet pipe of the LEL online monitor.

[0013] In some embodiments, the LEL online monitor is connected to a flow meter, and an air outlet pipe of the LEL online monitor is connected to an air inlet pipe of the flow meter.

[0014] In some embodiments, the flow meter is connected to a vacuum generator, and an outlet pipe of the flow meter is connected to a negative pressure port of the vacuum generator via a capillary tube.

[0015] In some embodiments, the vacuum generator includes at least an instrument air source inlet and an instrument air pressure reducing valve, wherein the instrument air source inlet is connected to the instrument air pressure reducing valve via a capillary, and the instrument air pressure reducing valve is connected to a vacuum generator instrument air valve on a side away from the vacuum generator.

[0016] In some embodiments, the exhaust port of the vacuum generator is connected to the exhaust pipe through a capillary tube.

[0017] Compared with the prior art, the present application has the following beneficial effects: the device of the present application can effectively remove moisture and particulate matter from the sample gas, reducing the frequency of maintenance of the detector; at the same time, the present application improves the stable operation of the LEL monitor through a dehydrator, a dehydrator drain valve, a vortex tube cooler and a precision filter, thereby effectively ensuring the safe operation of waste gas incinerator equipment such as RTO. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the principle structure of the device of this application.

[0020] Legend:

[0021] 1- dehydrator; 2- vortex tube cooler; 3- dehydrator drain valve; 4- precision filter; 5- flow meter, 6- LEL online monitor; 7- vacuum generator; 8- vacuum generator instrument air pressure reducing valve; 9- standard gas inlet valve; 10- sample gas thermometer; 11- waste gas pipeline; 12- vortex tube cooler instrument air valve; 13- vacuum generator instrument air valve; 14- sample gas cut-off valve; 15- waste gas pipeline flange sampling interface; 16- waste gas pipeline sample gas return flange interface; Figure 1 The solid arrow in the figure indicates the flow direction of the exhaust gas in the exhaust gas duct. DETAILED DESCRIPTION

[0022] The following is a diagram of the embodiments of the present application. Figure 1 The technical solutions in the embodiments of the present application are described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0023] Application Overview

[0024] With the continuous acceleration of the industrialization process, waste gas treatment has become an important task in the field of environmental protection. In the process of waste gas treatment, RTO (Regenerative Thermal Oxidizer) technology is widely used. It decomposes harmful substances in organic waste gas through high-temperature oxidation and converts them into harmless carbon dioxide and water vapor. In the process of RTO waste gas treatment, LEL combustible gas concentration monitor plays a vital role. LEL combustible gas concentration monitor can help optimize the operating efficiency of the RTO waste gas treatment system. By real-time monitoring of the combustible gas concentration in the waste gas, the operator can adjust the working parameters of the RTO system according to the monitoring results to achieve the best treatment effect. This can not only improve the efficiency of waste gas treatment, but also reduce energy consumption and operating costs, achieving both economic and environmental benefits.

[0025] Based on the above, this application provides a VOCs exhaust gas LEL monitoring device that can effectively remove moisture and particulate matter in the sample gas and reduce the maintenance frequency of the detector by linearly connecting a dehumidifier, a dehumidifier drain valve, a vortex tube cooler and a precision filter.

[0026] In order to better understand the following embodiments, some of the terms involved in this application are now explained:

[0027] 1. Exhaust gas LEL: refers to the lowest concentration of combustible gas that explodes when encountering open flames in the air;

[0028] 2. VOCs: refers to organic compounds that have a high saturated vapor pressure (greater than 13.33 Pa), a low boiling point, a small molecular weight, and are easy to volatilize at room temperature under standard conditions. This substance is one of the main pollutants in the atmosphere and is often represented by VOC or VOCs.

[0029] Example

[0030] This embodiment provides a VOCs waste gas LEL monitoring device, including a device body. It can be understood that the device body in this embodiment is a general term for the overall structure of the device, and is not limited to a single structure.

[0031] The device body at least includes a dehumidifier 1, a dehumidifier drain valve 3, a vortex tube cooler 2 and a precision filter 4. For details, refer to the attached Figure 1 The dehydrator 1 is detachably connected to the vortex tube refrigerator 2, the dehydrator drain valve 3 is connected to the dehydrator 1, the precision filter 4 is spaced apart from the dehydrator 1, the dehydrator drain valve 3 is spaced apart from the precision filter 4, and the dehydrator drain valve 3 is spaced apart from the vortex tube refrigerator 2.

[0032] It should be noted that the dehydrator 1 and the sample gas cut-off valve 14 are connected in sequence between the dehydrator drain valve 3 and the precision filter 4 , and the dehydrator 1 is connected between the dehydrator drain valve 3 and the vortex tube cooler 2 .

[0033] In some possible implementations, the water remover 1 includes a heat exchange coil, and the vortex tube cooler 2 is connected to the heat exchange coil through a capillary tube, wherein the capillary tube material may be polytetrafluoroethylene or stainless steel, and a ferrule joint is used at the pipe connection. It should be noted that cold air is passed through the heat exchange coil to cool the sample gas, plastic particles are filled in the dehumidifier 1 as dehydration filler, a drain pipe is led out from the bottom of the dehumidifier 1, and a double ball valve is arranged on the drain pipe. After the sample gas enters from the bottom of the dehumidifier 1 and is cooled by the dehumidifier 1, the water vapor in the gas becomes liquid water. After the sample gas passes through the dehydration filler, the free water and water vapor condensation water are removed by the dehydration filler, and the removed water is diverted to the drainage pipe at the bottom of the demister, and two ball valves are arranged on the drainage pipe. When draining the accumulated liquid, first open the upper ball valve to drain the accumulated liquid and then close it, and then open the lower ball valve to drain the accumulated liquid. Setting two drainage ball valves can prevent air from entering the sampling system from the drainage valve when draining the accumulated liquid and affecting the monitoring results.

[0034] In some possible implementations, the air inlet pipe of the water eliminator 1 is connected to the exhaust gas pipeline, wherein the air inlet pipe is connected to the exhaust gas pipeline flange sampling interface 15 through a thin tube, and a ferrule joint can be used at the pipe mouth connection. It should be noted that the capillary material can be polytetrafluoroethylene or stainless steel. The air outlet pipe of the water eliminator 1 is connected to the precision filter 4 via the sample gas cut-off valve 14. In other possible implementations, the aforementioned sample gas cut-off valve 14 is provided with a bypass line, and the bypass line is made of polytetrafluoroethylene tube or stainless steel capillary, and is connected and installed at the same time. Standard gas inlet valve 9.

[0035] In some possible implementations, the dehydrator drain valve 3 is connected to the dehydrator 1 through a water storage pipe, wherein the dehydrator drain valve 3 and the dehydrator 1 drain pipe are connected through a threaded interface, and the water storage pipe is connected between the two drain valves.

[0036] In some possible implementations, the precision filter 4 is connected to the LEL online monitor 6, and the air outlet pipe of the precision filter 4 is connected to the air inlet pipe of the LEL online monitor 6, wherein the air outlet pipe of the precision filter 4 is connected to the air inlet pipe of the LEL online monitor 6 through a capillary tube, and a ferrule joint is used at the pipe mouth connection, and a thermometer is installed at the connecting pipe outlet. It should be noted that the capillary tube material can be polytetrafluoroethylene material or stainless steel material.

[0037] In some possible implementations, the LEL online monitor 6 is connected to the flow meter 5, and the outlet pipe of the LEL online monitor 6 is connected to the inlet pipe of the flow meter 5, wherein the outlet pipe of the LEL online monitor 6 is connected to the inlet pipe of the flow meter 5 through a capillary tube, and a ferrule joint is used at the pipe mouth connection. It should be noted that the capillary tube can be made of polytetrafluoroethylene or stainless steel.

[0038] In some possible implementations, the flow meter 5 is connected to the vacuum generator 7, and the air outlet pipe of the flow meter 5 is connected to the negative pressure port of the vacuum generator 7 through a capillary tube. The air outlet pipe of the flow meter 5 is connected to the negative pressure port of the vacuum generator 7 through a capillary tube, and a ferrule joint is used at the pipe port connection. It should be noted that the capillary tube material can be polytetrafluoroethylene material or stainless steel material.

[0039] In some possible implementations, the vacuum generator 7 includes at least an instrument air source inlet and an instrument air pressure reducing valve 8, wherein the instrument air source inlet is connected to the instrument air pressure reducing valve 8 through a capillary, and the side of the instrument air pressure reducing valve 8 away from the vacuum generator 7 is connected to a vacuum generator instrument air valve 13.

[0040] In some possible implementations, the exhaust port of the vacuum generator 7 is connected to the exhaust pipe through a capillary tube. The exhaust port of the vacuum generator 7 is connected to the exhaust pipe sample gas return flange interface 16 through a capillary tube, and a ferrule joint is used at the pipe mouth connection. It should be noted that the capillary tube material can be polytetrafluoroethylene material or stainless steel material.

[0041] In order to better understand the principle of this embodiment, some technical features involved in this embodiment are now described:

[0042] The main function of the dehumidifier is to preliminarily process the sample gas and remove the moisture and impurities in the sample gas;

[0043] The main function of the dehumidifier drain valve is to discharge the accumulated liquid in the dehumidifier;

[0044] The precision filter is mainly used to remove trace impurities in the sample gas after being treated by the dehydrator;

[0045] The flow meter mainly displays the volume of the sampled gas flow;

[0046] The thermometer is mainly used to detect the temperature of the sample gas after cooling;

[0047] Vortex tube cooler is a kind of device that uses the function of vortex tube to make the instrument air generated under high-speed flow conditions to generate vortex to separate cold and hot airflows, and connect the cold airflow to the heat exchange coil of the dehumidifier device to cool the sample gas. The instrument air can use compressed air with a pressure of 0.2-0.5Mpa. The temperature of the sample gas after cooling can be adjusted by adjusting the pressure of the instrument air. The greater the pressure of the instrument air, the lower the temperature of the sample gas after cooling, and the smaller the pressure of the instrument air, the higher the temperature of the sample gas after cooling. In actual application, the pressure of the instrument air can be adjusted according to the thermometer reading;

[0048] The vacuum generator is a vacuum component that uses a positive pressure gas source to generate negative pressure. The positive pressure gas source uses 0.1-0.5Mpa compressed air. The negative pressure interface of the vacuum generator is connected to the sample gas sampling tube as the power for sample gas extraction. The sample gas flow rate can be adjusted by adjusting the compressed air pressure. The greater the pressure of the compressed air, the greater the sample gas flow rate, and the smaller the pressure of the compressed air, the smaller the sample gas flow rate. In actual application, the compressed air pressure can be adjusted by the flow meter indication. The exhaust port of the vacuum generator is connected to the exhaust pipe to discharge the detected sample gas back into the exhaust pipe.

[0049] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or basic features of the present application. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present application is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present application. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0050] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A VOCs waste gas LEL monitoring device, comprising a device body, characterized in that: The device body at least comprises a dehumidifier (1), a dehumidifier drain valve (3), a vortex tube refrigerator (2) and a precision filter (4); the dehumidifier (1) is detachably connected to the vortex tube refrigerator (2); the dehumidifier drain valve (3) is connected to the dehumidifier (1); the precision filter (4) is spaced apart from the dehumidifier (1); the dehumidifier drain valve (3) is spaced apart from the precision filter (4); and the dehumidifier drain valve (3) is spaced apart from the vortex tube refrigerator (2).

2. The device according to claim 1, characterized in that The dewatering device (1) comprises a heat exchange coil.

3. The device according to claim 2, characterized in that The air inlet pipe of the dehydrator (1) is connected to the exhaust gas pipeline, and the air outlet pipe of the dehydrator (1) is connected to the precision filter (4) at intervals by connecting the sample gas cut-off valve (14).

4. The device according to claim 1, characterized in that The dewatering device drain valve (3) is connected to the dewatering device (1) via a water storage pipe.

5. The device according to claim 2, characterized in that The vortex tube refrigerator (2) is connected to the heat exchange coil via a capillary tube.

6. The device according to claim 1, characterized in that The precision filter (4) is connected to an LEL online monitor (6), and the air outlet pipe of the precision filter (4) is connected to the air inlet pipe of the LEL online monitor (6).

7. The device according to claim 6, characterized in that The LEL online monitor (6) is connected to a flow meter (5), and an air outlet pipe of the LEL online monitor (6) is connected to an air inlet pipe of the flow meter (5).

8. The device according to claim 7, characterized in that The flow meter (5) is connected to a vacuum generator (7), and the air outlet pipe of the flow meter (5) is connected to the negative pressure port of the vacuum generator (7) via a capillary tube.

9. The device according to claim 8, characterized in that The vacuum generator (7) comprises at least an instrument air source inlet and an instrument air pressure reducing valve (8), wherein the instrument air source inlet is connected to the instrument air pressure reducing valve (8) via a capillary tube, and a vacuum generator instrument air valve (13) is connected to the instrument air pressure reducing valve (8) at a side away from the vacuum generator (7).

10. The device according to claim 8, characterized in that The exhaust port of the vacuum generator (7) is connected to the exhaust gas pipeline via a capillary tube.

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