A dioxin sampling system

Abstract

A novel dioxin sampling system provided by the present invention utilizes an eddy current tube without moving parts, reducing the demand for on-site power supply. At the same time, combined with the use of a large number of valves at the boiler site to use compressed air as power, it is introduced into a sampling gun annular sandwich provided in the inner cavity of the tail section outside the flue, and the temperature of the sampled flue gas is adjusted. The characteristics that compressed air interfaces are left at multiple parts of the furnace and the flue achieve the effect of convenient access, and the advantages of rapid refrigeration and heating can be realized without refrigerant. The heating device, refrigerator and their auxiliary equipment of the dioxin collection device in the prior art are cancelled, improving the reliability, portability and adaptability of the layout of the dioxin sampling device.

Description

Technical Field

[0001] The present invention relates to the field of fixed source pollutant monitoring, and particularly to a dioxin sampling system. Background Art

[0002] In the existing dioxin sampling methods, in order to ensure that the water vapor in the flue gas does not condense inside the barrel during isokinetic sampling, a barrel heating device usually needs to be added.

[0003] In addition, when passing through the gas capture device, in order to separate and store the water condensed from the waste gas, a set of refrigerating machine, refrigerant and its auxiliary equipment also need to be added. However, due to the limitations of the production site conditions, generally the available test platform is small and the power supply interfaces are insufficient. Especially for sampling for scientific research purposes, in order to analyze the parts where dioxin is easily generated and control measures, sampling may be required at multiple points in the entire flue gas process in addition to the chimney. These sampling points often have narrow channels and platforms and no power supply layout, resulting in difficult sampling situations. Summary of the Invention

[0004] Aiming at the problem of difficult dioxin sampling in the prior art, the present invention provides a dioxin sampling system.

[0005] The present invention is realized through the following technical solutions:

[0006] A dioxin sampling system includes a sampling gun, a vortex tube and a gas capture device;

[0007] The tail end of the sampling gun is sequentially connected to a filter cartridge and a gas capture device;

[0008] A sampling gun annular interlayer is sleeved outside the tail section of the sampling gun and the filter cartridge to form a sealed sampling gun annular interlayer space;

[0009] The vortex tube is provided with a compressed air interface for accessing compressed air. The hot air outlet is connected to one end of the filter cartridge in the sampling gun annular interlayer space through a hot air pipeline, and the cold air outlet is connected to a cooling device arranged outside the gas capture device.

[0010] Further, a cold air branch that merges with the hot air pipeline is also arranged at the cold air outlet.

[0011] Further, a heat preservation hot air outlet is arranged at one end of the sampling gun annular interlayer away from the filter cartridge.

[0012] Further, a pitot tube and a thermocouple are arranged on the lower side of the gun head at the end of the sampling gun. The output end of the pitot tube is connected to a micromanometer, and the output end of the thermocouple is connected to a thermocouple thermometer.

[0013] Further, the output end of the gas capture device is sequentially connected to a flow meter and a variable-frequency air extraction pump; and the output ends of the micro manometer, the thermocouple thermometer, and the flow meter are connected to a terminal, and the output end of the terminal is connected to the variable-frequency air extraction pump.

[0014] Further, a thermostatic chamber is further included, and the cooling device is arranged inside the thermostatic chamber.

[0015] Further, the cooling device adopts finned cooling tubes, and the finned cooling tubes are sleeved on the outer periphery of the gas capture device.

[0016] Further, a hot air temperature regulating valve is arranged at the hot air outlet of the vortex tube, and a hot air vent valve to the air and a hot air outlet shut-off valve are sequentially arranged on the hot air pipeline.

[0017] Further, a spiral plate structure is arranged on the inner wall of the annular interlayer of the sampling gun and is arranged in a fitting manner with the outer wall of the sampling gun.

[0018] Further, the sampling gun is provided with a flange for connecting to the flue.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects:

[0020] A novel dioxin sampling device provided by the present invention uses a vortex tube without moving parts, reducing the demand for site power. At the same time, combined with the use of compressed air as power for many valves at the boiler site, it is introduced into the annular interlayer of the sampling gun arranged in the inner cavity of the tail section outside the flue, and the temperature of the sampled flue gas is adjusted. The characteristics that compressed air interfaces are left at multiple parts of the furnace and the flue achieve the effect of convenient access, and the advantages of rapid refrigeration and heating can be achieved without a refrigerant. The heating device, the refrigerator and their auxiliary equipment of the dioxin collection device in the prior art are cancelled, improving the reliability, portability and adaptability of the dioxin sampling device layout.

[0021] Further, the temperature of the annular interlayer of the sampling gun is specifically adjusted by the cold and hot air in the vortex tube, so that the temperature of the flue gas is reduced to the normal working temperature range of the filter cartridge.

[0022] Further, a pitot tube and a thermocouple are arranged at the gun head of the sampling gun end for monitoring the pressure and temperature of the flue gas, providing a reference for the temperature control of the flue gas in the annular interlayer of the sampling gun.

[0023] Further, the signals of the micro manometer, the thermocouple thermometer, and the flow measurement point are respectively introduced into the terminal. After analysis and calculation by the terminal, a control command is sent to the variable-frequency air extraction pump for precise control of the sampling flow rate.

[0024] Furthermore, a spiral plate structure is provided on the inner wall of the annular interlayer of the sampling gun and is arranged in close contact with the outer wall of the sampling gun. When hot and cold air enters the annular interlayer space of the sampling gun, a flow mode that circulates around the sampling gun is formed, which can increase the heat transfer coefficient between the heat preservation air and the inner wall of the gun barrel and improve the heat conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG. 1 is a schematic diagram of a dioxin sampling system in a specific embodiment of the present invention.

[0026] In the figure: Pitot tube 2, thermocouple 3, sampling gun 4, flue wall surface 5, flange 6, heat preservation hot air outlet 7, annular interlayer of sampling gun 8, filter cartridge 9, hot air discharge valve to the air 10, hot air temperature regulating valve 11, compressed air interface 12, cold air outlet 13, hot air outlet shut-off valve 14, cold air to gun barrel temperature regulating valve 15, micro manometer 16, thermocouple thermometer 17, constant temperature box 18, finned cooling tube 19, gas capture device 20, flow meter 21, flow regulating valve 22, variable frequency air extraction pump 23, terminal 24, vortex tube 25, hot air outlet 26. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following further describes the present invention in detail with reference to the drawings, which is an explanation rather than a limitation of the present invention.

[0028] A dioxin sampling system of the present invention, as Figure 1 shown, includes a sampling gun 4, a vortex tube 25 and a gas capture device 20; the tail end of the sampling gun 4 is sequentially connected with a filter cartridge 9 and a gas capture device 20, and the tail section of the sampling gun 4 outside the flue and the outer periphery of the filter cartridge 9 are sleeved with an annular interlayer 8 of the sampling gun to form an annular interlayer space of the sampling gun; a cooling device is arranged outside the gas capture device 20; the input end of the vortex tube 25 is connected with compressed air, the hot air outlet 26 is connected to one end of the filter cartridge 9 in the annular interlayer space of the sampling gun through a hot air pipeline, and the cold air outlet 13 is connected to the cooling device. Specifically, solid-phase particles in the flue gas are captured by the filter cartridge 9, and the gas phase enters the gas capture device 20; at the same time, the vortex tube 25 is selected with a compressed air inlet pressure of 0.4 - 0.7 Mpa, the temperature of the cold air outlet 13 is 20 - 45 °C lower than the temperature of the compressed air at the inlet of the vortex tube 25, and the highest temperature of the hot air outlet 26 is 125 °C.

[0029] Preferably, a cold air branch is also provided at the cold air outlet 13 of the vortex tube 25, which merges with the hot air pipeline of the hot air outlet 26 and is connected to the annular sandwich space of the sampling gun, so that the hot and cold air of the vortex tube 25 can be introduced into the annular sandwich space of the sampling gun to adjust the temperature of the sampled flue gas. The inner wall of the annular sandwich 8 of the sampling gun is provided with a spiral plate structure and is attached to the outer wall of the sampling gun 4. When the hot and cold air enters the annular sandwich space of the sampling gun, a flow mode that circulates around the sampling gun 4 is formed, which can increase the heat transfer coefficient between the heat preservation air and the inner wall of the gun barrel and improve the heat conversion efficiency.

[0030] In a preferred embodiment provided by the present invention, a heat preservation hot air outlet 7 is provided at one end of the annular sandwich 8 of the sampling gun away from the filter cartridge 9. Specifically, after the hot and cold air of the vortex tube 25 enters the annular sandwich 8 through the compressed air interface 12, it first passes through the filter cartridge 9 and then is discharged through the heat preservation hot air outlet 7, so as to increase the heat conversion duration of the temperature adjustment of the flue gas inside the annular sandwich 8 of the sampling gun by the hot and cold air.

[0031] In another preferred embodiment provided by the present invention, a pitot tube 2 and a thermocouple 3 are provided on the lower side of the gun head at the end of the sampling gun 4. The output end of the pitot tube 2 is connected to a micromanometer 16, and the output end of the thermocouple 3 is connected to a thermocouple thermometer 17. Specifically, the pitot tube 2 and the thermocouple 3 can be closely arranged at the gun head at the end of the sampling gun 4. Among them, the pitot tube 2 is used to measure the total pressure and static pressure of the flue gas flow at the gun head at the end of the sampling gun 4 to determine the gas flow velocity and feedback it to the micromanometer 16, and the thermocouple 3 is used to measure the temperature at the gun head at the end of the sampling gun 4 and feedback it to the thermocouple thermometer 17.

[0032] In another preferred embodiment provided by the present invention, a constant temperature box 18 is provided outside the gas capture device 20 and the cooling device; specifically, the cooling device can adopt a finned cooling tube 19, and the finned cooling tube 19 is sleeved on the outer periphery of the gas capture device 20. The cold air outlet 13 of the vortex tube 25 is connected to the finned cooling tube 19 for cooling the flue gas to be measured. The fins therein can enhance the cooling effect and improve the heat absorption efficiency; at the same time, the constant temperature box 18 provides a stable environment, which is conducive to the accuracy of subsequent detection.

[0033] In another preferred embodiment provided by the present invention, a flange 6 is provided in the system for connecting to the flue; at the same time, the pitot tube 2 and the thermocouple 3 are also fixedly arranged on the flue wall surface 5 through the flange 6. The flange is very conducive to installation and disassembly, and facilitates the installation of this device on the flue wall surface 5.

[0034] Another preferred embodiment provided by the present invention is that the cold air outlet 13 of the vortex tube 25 is connected to the tail of the sampling gun 4 through the hot air outlet shut-off valve 14. At the same time, a hot air temperature regulating valve 11 is provided at the hot air outlet 26 of the vortex tube 25. A hot air vent valve 10 and a hot air outlet shut-off valve 14 are sequentially arranged on the hot air pipeline of the hot air outlet 26. Specifically, compressed air enters the vortex tube 25 through the compressed air interface 12. The generated cold air is introduced into the finned cooling tube 19 through the cold air outlet 13. After the hot air merges with the cold air in the cold air branch through the hot air outlet 26, it is introduced into the sandwich annular space 8 of the sampling gun 4 through the hot air pipeline for temperature adjustment and discharged through the heat-insulated hot air outlet 7. Specifically, the temperature of the gun barrel wall surface can be regulated between 105 °C and 125 °C by adjusting the hot air temperature regulating valve 11. When sucking waste gas exceeding 500 °C, the hot air outlet shut-off valve 14 can be closed, and the hot air vent valve 10 and the cold air to gun barrel temperature regulating valve 15 can be opened to reduce the flue gas temperature to the normal working temperature range of the filter cartridge 9.

[0035] Specifically, the source of the compressed air can adopt the instrument air or the plant air in the factory area.

[0036] Another preferred embodiment provided by the present invention is that the output end of the gas capture device 20 is sequentially connected to the flowmeter 21 and the variable frequency air extraction pump 23. A flow regulating valve 22 is arranged between the flowmeter 21 and the variable frequency air extraction pump 23. Among them, the flow regulating valve 22 can be automatically controlled to assist the variable frequency air extraction pump 23 to accurately control the air extraction flow rate. And the output ends of the micro-pressure gauge 16, the thermocouple thermometer 17 and the flowmeter 21 are connected to the terminal 24, and the output end of the terminal 24 is connected to the variable frequency air extraction pump 23. Specifically, the terminal 24 can adopt a microcomputer.

[0037] The above content only illustrates the technical idea of the present invention and cannot limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A dioxin sampling system, characterized in that, It includes a sampling gun (4), a vortex tube (25) and a gas trapping device (20); The tail end of the sampling gun (4) is sequentially connected to a filter cartridge (9) and a gas trapping device (20); A sampling gun annular sandwich (8) is sleeved on the outer periphery of the tail section of the sampling gun (4) and the filter cartridge (9) to form a sealed sampling gun annular sandwich space; a spiral plate structure is arranged on the inner wall of the sampling gun annular sandwich (8) and is attached to the outer wall of the sampling gun (4); The vortex tube (25) is provided with a compressed air interface (12) for accessing compressed air, a hot air outlet (26) is connected to one end of the filter cartridge (9) in the sampling gun annular sandwich space through a hot air pipeline, and a cold air outlet (13) is connected to a cooling device arranged outside the gas trapping device (20); The cold air outlet (13) is also provided with a cold air branch that merges with the hot air pipeline, and is used for the cold air branch to access the sampling gun annular sandwich space, and the hot and cold air of the vortex tube (25) is accessed in the sampling gun annular sandwich space to adjust the temperature of the sampled flue gas.

2. The dioxin sampling system according to claim 1, wherein One end of the sampling gun annular sandwich (8) away from the filter cartridge (9) is provided with a heat preservation hot air outlet (7).

3. The dioxin sampling system according to claim 1, characterized in that, A pitot tube (2) and a thermocouple (3) are arranged on the lower side of the gun head at the end of the sampling gun (4), the output end of the pitot tube (2) is connected to a micro manometer (16), and the output end of the thermocouple (3) is connected to a thermocouple thermometer (17).

4. The dioxin sampling system according to claim 1, wherein, The output end of the gas trapping device (20) is sequentially connected to a flow meter (21) and a variable frequency exhaust pump (23); and the output ends of the micro manometer (16), the thermocouple thermometer (17) and the flow meter (21) are connected to a terminal (24), and the output end of the terminal (24) is connected to the variable frequency exhaust pump (23).

5. The dioxin sampling system according to claim 1, wherein, It also includes a constant temperature box (18), and the cooling device is arranged inside the constant temperature box (18).

6. The dioxin sampling system according to claim 1 or 5, characterized in that The cooling device adopts a finned cooling tube (19), and the finned cooling tube (19) is sleeved on the outer periphery of the gas trapping device (20).

7. The dioxin sampling system according to claim 1, characterized in that, A hot air temperature regulating valve (11) is arranged at the hot air outlet (26) of the vortex tube (25), and a hot air vent valve (10) and a hot air outlet shut-off valve (14) are sequentially arranged on the hot air pipeline.

8. The dioxin sampling system according to claim 1, wherein The sampling gun (4) is provided with a flange (6) for connecting to the flue.

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