Multi-stage dielectric barrier discharge plasma synergistic catalytic treatment device for waste gas and wastewater

Abstract

The invention discloses a multi-stage dielectric barrier discharge plasma coordinated catalytic treatment device for waste gas and wastewater, comprising a shell, in which plasma generators and catalysts or adsorbents supported by porous tower plates are alternately arranged in sequence from the feed end to the discharge end, each plasma generator comprises a high-voltage electrode wrapped with a discharge dielectric layer and several barrier dielectric tubes perpendicular to the material flow direction, a low-voltage electrode is arranged in each barrier dielectric tube, the barrier dielectric tubes are evenly arranged with the high-voltage electrode as the center, the high-voltage electrode is connected to the high-voltage discharge device on the left, the low-voltage electrode is grounded on the right, and the catalyst or adsorbent supported by the porous tower plate can be loaded through several sealing doors with sealing rings on the shell. The invention has a simple structure and a reasonable design, can not only treat waste gas, but also purify wastewater, and can reduce the presence of secondary pollutants.

Description

Technical Field

[0001] The invention relates to a waste gas and waste water treatment device, in particular to a multi-stage dielectric barrier discharge plasma coordinated catalytic treatment device for waste gas and waste water. Background Art

[0002] With the development of science and technology, petrochemical and organic synthesis technologies have been continuously improving, and many chemical products have become more and more necessary for people's lives. On the one hand, these products have brought convenience to our lives; on the other hand, they will produce some waste gas and wastewater during the production and use process, which will cause certain harm to the human body. For example, VOCs mainly affect the central nervous system and hematopoietic system of the human body, especially the immune system and various organs; benzene series are the most harmful to human health, with strong blood toxicity and carcinogenicity; formaldehyde is the protagonist of indoor air pollution, which will cause damage to the respiratory system, digestive system, blood system, central nervous system and immune system, as well as kidneys and liver.

[0003] In addition, water resources are the material that humans and all living things rely on for survival. With the increase in population and the acceleration of industrialization and urbanization, water shortage has become an important problem faced by countries around the world. At the same time, the increase in sewage discharge has exacerbated the severity of this problem. Therefore, it is of great significance to study efficient, energy-saving and pollution-free technologies for treating waste gas and wastewater.

[0004] Most of the existing plasma treatment devices for waste gas and wastewater are single treatments, which do not conform to the current situation in which waste gas and wastewater are produced simultaneously in the actual production process. "CN 208694648 U" discloses a low-temperature plasma waste gas treatment generator. Although this equipment has a simple process and is easy to operate, and can be carried out under atmospheric pressure, the life of the plasma product is too short, and it is difficult to achieve full purification of pollutants. "CN 208553754 U" discloses a device for plasma coordinated adsorption and catalytic treatment of organic waste gas, which can efficiently treat organic waste gas, but the device can only treat waste gas and cannot treat wastewater, and in real life, waste gas and wastewater are often produced simultaneously. "CN104437021A" designs a plasma waste gas treatment device with an electrode module that can be quickly disassembled. The electrode of this design is detachable and easy to clean, but the electrode is poorly fixed, which is not conducive to uniform discharge of the electrode. CN105858988A discloses a method and device for treating wastewater with plasma-assisted catalysts. The device passes wastewater into a reactor with positive and negative electrodes. The treatment capacity is small and is not conducive to large-scale treatment of wastewater. CN108261897A designs a universal purification device for waste gas and wastewater. The device directly sprays the gas-liquid mixture into the reaction chamber through an atomizing nozzle. Due to the influence of gravity, the wastewater stays in the container for a short time and is not fully purified. At the same time, when treating waste gas, if the ozone generated by the plasma is not completely consumed, it will cause secondary pollution to the gas. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a multi-stage dielectric barrier discharge plasma synergistic catalytic treatment device for waste gas and wastewater, which can not only treat organic waste gas and purify wastewater, but also realize plasma synergistic catalyst treatment, thereby effectively improving the treatment effect of waste gas and wastewater.

[0006] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0007] The present invention is a multi-stage dielectric barrier discharge plasma coordinated catalytic treatment device for waste gas and wastewater, comprising a shell, in which plasma generators and catalysts or adsorbents supported by porous tower plates are alternately arranged in sequence from the feed end to the discharge end. Each plasma generator comprises a high-voltage electrode wrapped with a discharge dielectric layer and a plurality of barrier dielectric tubes perpendicular to the material flow direction. A low-voltage electrode is arranged in each barrier dielectric tube. The barrier dielectric tubes are evenly arranged with the high-voltage electrode as the center. The high-voltage electrode is connected to a high-voltage discharge device on the left, and the low-voltage electrode is grounded on the right. The catalyst or adsorbent supported by the porous tower plate can be loaded through a plurality of sealing doors with sealing rings on the shell.

[0008] A further improvement of the present invention is that the high voltage electrode is made of one of copper, tungsten, copper-tungsten alloy, and tungsten-molybdenum alloy, and its shape is one of tubular, stick-shaped, needle-shaped, and spiral.

[0009] A further improvement of the present invention is that the material of the discharge medium layer and the shell wrapped around the outside of the high-voltage electrode is one of quartz glass, tempered glass, ceramic, polytetrafluoroethylene, and epoxy resin.

[0010] A further improvement of the present invention is that the thickness of the discharge dielectric layer is 0.2-1 cm.

[0011] A further improvement of the present invention is that the cross-sectional area of ​​the shell is 100 cm 2 -5000 cm 2 , its thickness is 1-5cm.

[0012] A further improvement of the present invention is that a gas inlet and a liquid inlet are arranged at the feed end, and a discharge port shared by gas and liquid is arranged at the discharge end.

[0013] A further improvement of the present invention is that an atomizing nozzle is arranged at the lower end of the liquid inlet.

[0014] A further improvement of the present invention is that the thickness of the catalyst supported by the perforated tray is 1-10 cm, and the distance between two adjacent perforated trays is 10-50 cm.

[0015] A further improvement of the present invention is that the power supply of the high-voltage discharge device is a pulse, high-frequency or radio-frequency power supply, and the voltage is 0-500V.

[0016] A further improvement of the present invention is that the distance between the high voltage electrode and the low voltage electrode is 1-8 cm.

[0017] The beneficial effects of the present invention are: when organic waste gas enters the shell from the air inlet 3, or waste water sprays the water vapor mixture into the reaction chamber in the shell through the atomizing nozzle, the dielectric barrier discharge device in the chamber excites the generation of high-energy active particles and ozone, and oxidizes and decomposes the organic matter in the waste gas or waste water. In addition, the plasma synergistic catalyst can further enhance its decomposition of organic matter, and the porous tower plate can increase the retention time of the material, which is conducive to the uniform distribution of the waste gas or waste water in the reactor, so that the waste gas and waste water are purified more fully. The catalyst or adsorbent is placed at the lower end of the discharge area, and can selectively react with the intermediate by-products generated by the plasma to obtain an ideal degradation substance, reduce the presence of secondary pollutants, and the catalyst is easy to replace. A variety of different catalysts can be used for synergistic catalysis to improve the equipment's processing capacity for difficult-to-degrade substances.

[0018] The invention has a simple structure and a reasonable design, can not only process waste gas but also purify waste water and can reduce the presence of secondary pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the present invention.

[0020] Figure 2 It is a schematic diagram of the structure of a plasma generator.

[0021] Figure 3 is a side view schematic diagram of a plasma generator.

[0022] Figure 4 This is a schematic diagram of a sealed door.

[0023] Wherein: 1-high voltage discharge device, 2-high voltage electrode, 3-air inlet, 4-liquid inlet, 5-shell, 6-atomizing nozzle, 7-plasma generator, 8-low voltage electrode, 9-catalyst, 10-porous tower plate, 11-air outlet, 12-liquid outlet, 13-barrier medium tube, 14-discharge medium layer, 15-sealing ring, 16-sealing door. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. The accompanying drawings provide a preferred embodiment, and the present invention can be implemented in various forms. Therefore, the scope of protection is not limited to the description of this embodiment, and the examples are provided for a better understanding of the implementation of the present invention.

[0025] like Figure 1-4As shown, the present invention is a multi-stage dielectric barrier discharge plasma synergistic catalytic treatment device for waste gas and wastewater, including a shell 5, in which plasma generators 7 and catalysts 9 or adsorbents supported by perforated tower plates 10 are alternately arranged in sequence from the feed end to the discharge end. The catalyst 9 or adsorbent is placed on the rear side of the plasma generator to effectively reduce the possibility of the presence of secondary pollutants. Each plasma generator 7 includes a high-voltage electrode 2 wrapped with a discharge dielectric layer 14 perpendicular to the material flow direction and several blocking dielectric tubes 13, the number of the blocking dielectric tubes 13 is 6, and a low-voltage electrode 8 is arranged in each blocking dielectric tube 13. The distance between the high-voltage electrode 2 and the low-voltage electrode 8 is 1-8 cm, which ensures the uniformity of the discharge. The preferred distance is 3.5 cm, the barrier medium tube 13 is evenly arranged with the high-voltage electrode 2 as the center, the high-voltage electrode 2 is connected to the high-voltage discharge device 1 on the left, the power supply of the high-voltage discharge device 1 is a pulse, high-frequency or radio frequency power supply, and the voltage is 0-500v, wherein the preferred power supply of the high-voltage discharge device 1 adopts a 220V pulse power supply, the right side of the low-voltage electrode 8 is grounded, and the catalyst 9 or adsorbent supported by the porous tower plate 10 can be loaded through several sealing doors 16 with sealing rings 15 on the shell 5. The sealing door 16 is convenient for replacing and loading the catalyst 9.

[0026] The material of the high-voltage electrode 2 is one of copper, tungsten, copper-tungsten alloy, and tungsten-molybdenum alloy, and its shape is one of tubular, stick-shaped, needle-shaped, and spiral-shaped. The thickness of the discharge dielectric layer 14 wrapped around the outside of the high-voltage electrode 2 is 0.2-1 cm, and the preferred thickness is 0.3 cm. The discharge dielectric layer 14 can effectively protect the high-voltage electrode 2. The materials of the discharge dielectric layer and the shell 5 wrapped around the outside of the high-voltage electrode 2 are one of quartz glass, tempered glass, ceramic, polytetrafluoroethylene, and epoxy resin. The cross-sectional area of ​​the shell 5 is 100 cm 2 -5000 cm 2 , and its thickness is 1-5 cm. Preferably, the cross-sectional area of ​​the shell 5 is 400 cm 2 The quartz glass shell 5 has a thickness of 1 cm. The catalyst supported by the porous tray 10 can be loaded through the sealing door 16, which is convenient for replacing the catalyst. The presence of the porous tray 10 is conducive to the redistribution of gas and liquid in the reactor, so that the purification of wastewater and waste liquid is more uniform. The thickness of the catalyst supported by the porous tray 10 is 1-10 cm, and the distance between two adjacent porous trays 10 is 10-50 cm. Preferably, the thickness of the catalyst supported by the porous tray 10 is 3 cm, and the spacing between the porous trays 10 is 15 cm. The porous tray 10 is conducive to the redistribution of waste gas or wastewater in the shell 5, so that the purification of wastewater and waste gas is more uniform.

[0027] An air inlet 3 and a liquid inlet 4 are provided at the feed end, and an air outlet 11 and a liquid outlet 12 are provided at the discharge end. The air outlet 11 and the liquid outlet 12 are led out from the same outlet on the shell 5, and an atomizing nozzle 6 is provided at the lower end of the liquid inlet 4. When the exhaust gas enters the shell 5 from the air inlet 3 or the wastewater sprays the water vapor mixture into the shell 5 through the atomizing nozzle 6, the plasma generator 7 excites and produces high-energy active particles and ozone to oxidize and decompose the organic matter in the exhaust gas or wastewater. In addition, the plasma synergistic catalyst 9 can further enhance its decomposition of organic matter and finally meet the emission standards. The removal effect can be enhanced by using different types of catalysts 9, and the purpose of high purification can be achieved by layered treatment. The catalyst 9 is supported by the porous tower plate 10, and the gas or liquid entering the shell 5 can be redistributed, thereby making the exhaust gas or wastewater more fully purified.

[0028] The invention has a simple structure and a reasonable design, can not only process waste gas but also purify waste water and can reduce the presence of secondary pollutants.

Claims

1. A multi-stage dielectric barrier discharge plasma synergistic catalytic treatment device for waste gas and wastewater, comprising a housing (5), characterized in that: Plasma generators (7) and catalysts (9) or adsorbents supported by porous trays (10) are alternately arranged in sequence in the shell (5) from the feed end to the discharge end. Each of the plasma generators (7) comprises a high-voltage electrode (2) wrapped with a discharge medium layer (14) and a plurality of barrier medium tubes (13) perpendicular to the material flow direction. A low-voltage electrode (8) is arranged in each barrier medium tube (13). The barrier medium tubes (13) are evenly arranged with the high-voltage electrode (2) as the center. The high-voltage electrode (2) is connected to the high-voltage discharge device (1) on the left side, and the low-voltage electrode (8) is grounded on the right side. The catalyst (9) or adsorbent supported by the porous tray (10) can be loaded through a plurality of sealing doors (16) with sealing rings (15) on the shell (5). The thickness of the discharge medium layer (14) is 0.2-1. cm, an air inlet (3) and a liquid inlet (4) are provided at the feed end, an air outlet (11) and a liquid outlet (12) are provided at the discharge end, an atomizing nozzle (6) is provided at the lower end of the liquid inlet (4), the thickness of the catalyst supported by the porous tower plate (10) is 1-10 cm, the distance between two adjacent porous tower plates (10) is 10-50 cm, and the distance between the high-voltage electrode (2) and the low-voltage electrode (8) is 1-8 cm.

2. According to claim 1, the multi-stage dielectric barrier discharge plasma synergistic catalytic treatment device for waste gas and wastewater is characterized by: The high voltage electrode (2) is made of one of copper, tungsten, copper-tungsten alloy, and tungsten-molybdenum alloy, and has a shape of one of tubular, stick, needle, and spiral.

3. According to claim 2, the multi-stage dielectric barrier discharge plasma synergistic catalytic treatment device for waste gas and wastewater is characterized by: The material of the discharge dielectric layer wrapped around the outside of the high-voltage electrode (2) and the shell are both one of quartz glass, tempered glass, ceramic, polytetrafluoroethylene, and epoxy resin.

4. According to claim 3, the multi-stage dielectric barrier discharge plasma synergistic catalytic treatment device for waste gas and wastewater is characterized in that: The cross-sectional area of ​​the shell is 100 cm 2 -5000 cm 2 , its thickness is 1-5 cm.

5. According to claim 1, the multi-stage dielectric barrier discharge plasma synergistic catalytic treatment device for waste gas and wastewater is characterized by: The power supply of the high-voltage discharge device (1) is a pulse, high-frequency or radio-frequency power supply, and the voltage is 0-500V.

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