CN206597461U - The emission-control equipment of array plasma catalyst synergy - Google Patents

Abstract

The utility model belongs to the technical field of environmental protection, in particular to an array type plasma-catalyst synergistic exhaust gas treatment device. The utility model device comprises: a pulse power supply, a metal electrode, an insulating medium tube, a catalyst module and a casing; the metal electrode is inserted into the insulating medium tube as a plasma generating electrode, and the plasma generating electrodes are arranged in a geometric array, and the same row Among the electrodes, the high-voltage electrodes and the ground electrodes are arranged alternately; the catalyst module is inserted between two adjacent columns of plasma generating electrodes; the plasma is generated in the air gap between the electrodes in the same column, and the number of rows and columns of electrodes can be adjusted To meet the needs of exhaust gas treatment of different types, concentrations, and space velocities. The catalyst module is placed between two adjacent rows of electrodes, close to the plasma discharge area, so that the exhaust gas passes through the multi-layer plasma and the catalyst in sequence, which can not only prevent the catalyst structure from being damaged by the plasma, but also make the plasma discharge The active particles are in full contact with the catalyst to achieve efficient synergy.

Description

Array type plasma-catalyst synergistic exhaust gas treatment device

technical field

The utility model belongs to the technical field of environmental protection, and in particular relates to an array type plasma-catalyst synergistic waste gas treatment device.

Background technique

The air pollution caused by economic construction has become one of the most serious environmental problems. Industrial waste gas contains many toxic and harmful gases such as volatile organic compounds (VOCs), sulfur dioxide, nitrogen oxides, etc., which not only seriously harm the Human life is healthy, and it has great harm to the earth's ecological environment. Traditional waste gas treatment technologies such as incineration, adsorption, condensation, etc., have disadvantages such as low purification efficiency, high input cost, and easy to produce secondary pollution, making it difficult to meet the needs of modern industrial society.

Plasma is a collection of electrically neutral substances composed of ions, electrons, and neutral particles. It is the fourth state of matter different from solids, liquids, and gases. Known as low-temperature plasma, it is widely used in materials, electronics and other fields, and has attracted much attention in the field of environmental protection. The use of dielectric barrier discharge technology can generate a large area of low-temperature plasma under atmospheric pressure. There are a large number of high-energy electrons in the plasma, which inelastically collide with the background gas molecules in the exhaust gas, and generate a wide variety of excited state species through energy transfer. Positive and negative ions, free radicals and other active particles, among which components such as ozone, excited oxygen atoms, and hydroxyl radicals have strong oxidizing properties, which can oxidize and degrade toxic and harmful components in the exhaust gas, and convert them into non-toxic and harmless or Substances with low toxicity and low harm. Dielectric barrier discharge treatment of waste gas can be carried out at normal temperature and pressure, with convenient operation, simple operation, high treatment efficiency and low secondary pollution, and has broad application prospects.

Low-temperature plasma technology has the disadvantages of high energy consumption and easy production of various by-products in the treatment of waste gas. In order to solve this problem, plasma-catalysis synergistic technology has become a research hotspot. Utilizing the advantages of high plasma reactivity, combined with active catalysts, the energy efficiency of waste gas degradation can be significantly improved at room temperature, the generation of by-products can be reduced, and the conversion rate and mineralization rate of toxic and harmful gases can be improved. The traditional catalyst filling method is divided into one-stage and two-stage: one-stage is to place the catalyst inside the plasma reactor. This structure can make full use of the short-lived active substances generated in the plasma to catalyze the oxidation of exhaust gas molecules. The disadvantage is that the catalyst may be damaged if it is placed in the plasma for a long time; the two-stage type is to place the catalyst after the plasma reactor. This structure can prevent the catalyst structure from being damaged by the plasma. The disadvantage is that there are only long-lived active substances The catalyst layer can only be reached, and the catalyst needs to be regenerated or replaced after the adsorption is saturated.

Existing dielectric barrier discharge devices usually have shortcomings such as limited shape, small amount of processing gas, and difficult to replace electrodes. It is difficult to meet the needs of exhaust gas treatment of different types, concentrations, and space velocities, and it is difficult to maintain in the later stage. These factors limit the plasma device. It is widely used in the field of industrial waste gas treatment.

Contents of the invention

The utility model provides a plasma-catalysis synergistic industrial waste gas treatment device, aiming to solve the problems that the plasma generator has a small processing gas volume, is difficult to maintain, and the traditional catalyst filling method is difficult to effectively combine with the plasma.

The industrial waste gas treatment device with plasma-catalysis synergy proposed by the utility model is composed as shown in Figure 1 and Figure 2, including: pulse power supply, metal electrode, insulating medium tube, catalyst module and housing; wherein, a The metal electrode is inserted in an insulating dielectric tube as a plasma generating electrode. The insulating dielectric tube is a long columnar shape with one end closed and the other end open to lead out the metal electrode; the insulating dielectric tubes are arranged in a geometric array, and the same row The closed end and the open end of the medium insulating medium tube are arranged alternately. The metal electrode drawn in one direction is connected to the high-voltage output of the pulse power supply to become a high-voltage electrode, and the metal electrode drawn in the other direction is connected to the earth to become a ground electrode; in this way, the plasma is generated. The electrodes are arranged in a geometric array. In the same row of electrodes, the high-voltage electrodes and the ground electrodes are arranged alternately (that is, cross-distributed). When the output voltage of the power supply reaches the breakdown voltage, plasma will be generated between the adjacent high-voltage electrodes and the ground electrodes. ; The catalyst module is inserted between two adjacent rows of plasma generation electrodes, and the harmful gas is treated in cooperation with the plasma; the entire electrode array is installed in the casing.

In the utility model, in order to prevent ignition between the high-voltage electrode and the housing, a 1-2cm long vacuum area or medium layer is reserved at the closed end of the insulating medium tube, and the remaining part is filled with metal electrodes; the same row of plasma generating electrodes Among them, the distance between the cross-arranged high-voltage electrodes and the ground electrodes matches the output voltage of the pulse power supply, and can be adjusted between 1-10mm.

In the present invention, the size of the insulating medium pipe can be adjusted according to the actual situation, for example, the outer diameter is 2-5mm, the inner diameter is 1-3mm, and the length is 80mm-300mm.

In the utility model, the insulating medium tube is a high-voltage non-polar insulating material, which can be quartz glass, ceramics (such as alumina, zirconia, silicon nitride), epoxy resin, polytetrafluoroethylene, etc., and quartz Glass and ceramics are preferred; the metal electrode is a metal material with good conductivity, which can be gold, silver, copper, iron, aluminum, zinc, tungsten, platinum, palladium, iridium, stainless steel, etc., and can be a metal rod or metal powder If it is metal powder, it needs to lead out a wire after filling it into the insulating medium tube, and connect it to the external power supply.

In the utility model, the high-voltage electrode and the ground electrode are respectively drawn from two opposite sides and connected together through a metal plate (metal strip), so that the high-voltage electrode and the ground electrode maintain equal potentials; the plasma generating electrode and the The housing and the metal plate (metal strip) are connected by removable parts such as screws and buckles, which is convenient for electrode replacement.

In the utility model, the housing of the device is an easy-to-process and anti-corrosion insulating material, which can be plexiglass, polytetrafluoroethylene, epoxy and the like.

In the present invention, the length of the plasma generating electrodes, the number of electrodes in each row, the distance between electrodes in the same row and the number of rows of electrodes can all be adjusted. When the air velocity of the exhaust gas is constant, changing the electrode length, the number of electrodes in each column or the distance between electrodes in the same column can change the cross-sectional area of the generated plasma, thereby changing the residence time of the exhaust gas; changing the number of electrode columns can change the flow direction of the exhaust gas The length of the plasma region above can also change the residence time of the exhaust gas. Therefore, for a certain industrial waste gas, when ensuring sufficient residence time to achieve the desired degradation effect, the length of the plasma generation electrode, the number of electrodes in each column, the distance between electrodes in the same column and the distance between electrodes can be increased. The number of columns to increase the exhaust gas space velocity and increase the gas volume of the device to process the gas.

In the utility model, the distance between two adjacent rows of plasma generating electrodes is adjustable. The one-stage filling method of the catalyst may damage the catalyst structure, and the two-stage filling method will weaken the synergy between the active particles and the catalyst. Filling the catalyst between two adjacent rows of electrodes can not only avoid the destruction of the catalyst structure, but also The catalyst can be close to the plasma discharge area, so that the active particles generated by the plasma discharge can fully contact with the catalyst to produce a synergistic effect. By changing the distance between two adjacent rows of electrodes, the distance between the plasma discharge area and the catalyst module can be adjusted, so that a series of experiments can be performed to find the most suitable filling position of the catalyst and improve the system performance.

In the utility model, the pulse voltage generated by the pulse power supply applied to the plasma generating electrode is 1-100kV, and the frequency is 0-10kHz. Compared with the traditional AC power supply, the pulse power supply has smaller power, lower discharge gas temperature, more types of active particles, larger amount of ozone, better waste gas treatment effect and lower cost.

In the utility model, the catalyst module can be directly inserted between the plasma arrays in the form of pressing into sheets, or a mesh box made of pressure-resistant, temperature-resistant, and corrosion-resistant materials (polytetrafluoroethylene) can be used to fill the catalyst In the box; packed catalyst can be powder, granular, block and so on. Mesh box to allow exhaust gases to pass through. PTFE has good electrical insulation, corrosion resistance, anti-aging and high temperature resistance, non-toxic to the human body, and is a good packaging material.

In the utility model, the gas source can be air mixed with industrial waste gas, helium, argon, nitrogen, etc., and the gas pressure, temperature, humidity, flow rate, etc. can be selected according to requirements within a certain range.

The utility model can generate large-area plasma, and can meet the industrial waste gas treatment requirements of different types, concentrations and space velocities by adjusting the length, quantity and spacing of the plasma generating electrodes; the electrodes are detachable and easy to maintain; the catalyst and plasma The discharge area is distributed alternately, which makes up for the deficiency of the one-stage and two-stage filling methods of the catalyst, and can give full play to the synergistic effect of the plasma-catalyst; using the pulse power supply as the plasma generation source, it can generate plasma close to room temperature, with high energy efficiency. High, low operating costs.

Description of drawings

Fig. 1 is the plan view of the principle structure of the utility model.

Fig. 2 is the left view of the principle structure of the utility model.

detailed description

Fig. 1 and Fig. 2 are respectively the top view and the left view of the principle structure of the utility model, including a high voltage electrode 1, a ground electrode 2, an insulating medium pipe 3, a high voltage metal plate 4, a grounding metal plate 5, a catalyst module 6 and a pulse power supply 7. In this embodiment, there are 18 plasma generating electrodes in 3 columns×6 rows, all high-voltage electrodes 1 are connected to high-voltage metal plates 4 through terminal posts, and high-voltage metal plates are connected to the high-voltage output of pulse power supply 7; all ground electrodes 2 are connected to the ground The metal plate 4 is connected to the ground through a terminal; the high-voltage electrode 1 and the ground electrode 2 are placed in the insulating medium tube 3 to form a plasma generating electrode; the catalyst module 6 is placed in two adjacent columns of plasma generating electrodes. between the electrodes.

The flow direction of industrial waste gas is shown in the wind direction in Figure 1, and the waste gas alternately passes through the plasma discharge area and the catalyst module. There are a large number of high-energy electrons and strong oxidizing active particles in the plasma discharge area, which have physical and chemical reactions such as collision, cracking, and oxidation with harmful gas molecules in the exhaust gas, and the exhaust gas that has not been completely converted into harmless substances enters the subsequent catalyst The module, through adsorption and catalytic oxidation, greatly improves the conversion rate of harmful gases. If it passes through the multi-layer discharge area and the catalyst module, the exhaust gas is completely purified and meets the emission standard.

In the device of this embodiment, the high-voltage electrode 1 and the ground electrode 2 are copper rods with a length of 220 mm and an outer diameter of 2 mm; the insulating dielectric tube 3 is a quartz glass tube with a length of 200 mm, an outer diameter of 4 mm, and an inner diameter of 2 mm. The electrodes are inserted into the dielectric tube at the top A 10mm gap is left to provide insulation protection for the high voltage tip.

In the above device, the air gap interval between electrodes in the same row is 4mm, and the air gap interval between two adjacent rows of electrodes is 20mm. Molecular sieve is used as the catalyst, filled in a rectangular parallelepiped net box made of polytetrafluoroethylene, and inserted between adjacent electrodes. .

In the above device, the pulse power supply 7 is a high-frequency high-voltage unipolar pulse power supply, the frequency is adjustable from 0 to 10 kHz, and the voltage is adjustable from 0 to 30 kV.

The xylene simulated exhaust gas with a concentration of 200ppm and a space velocity of 10L/min was selected as the experimental sample gas. At a room temperature of 25°C, by adjusting the output voltage of the pulse power supply and the filling amount of the catalyst, the conversion rate of xylene can reach more than 95%. Carbon dioxide selectivity is above 60%.

For the actual exhaust gas, the type and filling amount of the catalyst shall depend on the situation. For low-concentration and small-volume easy-to-treat gases, the catalyst module may not be added, and only plasma can be used for treatment; for high-concentration and large-volume industrial waste gases, catalysts are added in sequence to explore the amount of catalyst required for the treatment results to meet the standard, so as to reduce the cost of the device. cost.

In practical applications, the number of columns, rows and lengths of plasma generating electrodes can be greatly changed according to actual conditions to meet the needs of industrial waste gas treatment of different types, concentrations, and space velocities; the row spacing between electrodes can be adjusted within an appropriate range, and The pulse power supply should be matched; the distance between the electrodes, the number of layers of the catalyst module, and the distance between the catalyst module and the electrodes should be determined according to the actual situation to maximize the efficiency of the system.

Claims (9)

1. a kind of emission-control equipment of array Plasma catalyst synergy, it is characterised in that including：Pulse electricity Source, metal electrode, insulated dielectric tube, catalyst module and housing；Wherein, a metal electrode is inserted in an insulated dielectric tube In, as plasma-generating electrode, the long strip type that insulated dielectric tube is in the form of a column, one end closing, another end opening is to draw gold Belong to electrode；Insulated dielectric tube is arranged in the form of geometric array, and in same row insulated dielectric tube end seal closing and opening mouthful end side To spaced, the metal electrode that side direction is drawn connects the High voltage output of the pulse power, as high-field electrode, opposite side direction The metal electrode of extraction connects the earth, as ground electrode；Plasma-generating electrode is so set to be arranged in the form of geometric array, together One row electrode mesohigh electrode and ground electrode interphase distribution；Catalyst module be inserted in adjacent two row plasma-generating electrode it Between；Whole electrod-array is arranged in housing.

2. the emission-control equipment of array Plasma catalyst synergy according to claim 1, its feature exists In the blind end of the insulated dielectric tube reserves the vacuum area of one section of 1-2cm length, or filled media layer, remainder filling Metal electrode；In same row plasma-generating electrode, spacing and pulse electricity between the high-field electrode and ground electrode of cross arrangement Source output voltage matches, and spacing is adjusted between 1-10mm.

3. the emission-control equipment of array Plasma catalyst synergy according to claim 1 or 2, it is special Levy and be, the insulated dielectric tube is high pressure resistant nonpolar insulating materials, selected from quartz glass, ceramics, epoxy resin, polytetrafluoro Ethene；The metal electrode is metal material with good conductivity, selected from gold, silver, copper, iron, aluminium, zinc, tungsten, platinum, palladium, iridium, no Become rusty steel, and its form is metal bar or metal dust, if metal dust then needs extraction one to lead after insulated dielectric tube is packed into Line, is connected with extraneous power supply or ground.

4. the emission-control equipment of array Plasma catalyst synergy according to claim 3, its feature exists In the high-field electrode is drawn and linked together by metallic plate respectively with ground electrode from two relative sides, makes high pressure Electrode is equal with each self-sustaining potential of ground electrode.

5. the emission-control equipment of the array Plasma catalyst synergy according to claim 1,2 or 4, its It is characterised by, is connected between plasma-generating electrode and housing, metallic plate by detachable blocks such as screw, buckles.

6. the emission-control equipment of array Plasma catalyst synergy according to claim 5, its feature exists The columns of distance and electrode is equal between the length of, the plasma-generating electrode, the radical of each column electrode, same column electrode It is adjustable.

7. the emission-control equipment of the array Plasma catalyst synergy according to claim 1,2,4 or 6, Characterized in that, it is 1-100kV that the pulse power, which puts on the pulse voltage produced on plasma-generating electrode, frequency is 0-10kHz。

8. the emission-control equipment of array Plasma catalyst synergy according to claim 7, its feature exists In, catalyst module is inserted directly between plasma array in tabletted form, or catalyst be filled in it is netted In box, between catalyst box insertion plasma array.

9. the emission-control equipment of array Plasma catalyst synergy according to claim 1, its feature exists In gas source is air, helium, argon gas or the nitrogen for being mixed with industrial waste gas.