Circulating DBD concerted catalysis air purification device and method

Abstract

According to the circulating DBD concerted catalysis air purification device and method, four three-electrode dielectric barrier discharge reactors are connected in series, and the purposes of thoroughly purifying air and reducing ozone are achieved. A two-stage reaction is adopted. In the first-section reaction, pollution gas enters the inner layer of the reactor through pressurization, is discharged from the tail end of the inner-layer glass tube after cooperative treatment, and is subjected to the second-section reaction in the outer-layer glass tube. The three-electrode sectional treatment greatly increases the contact area of the pollution gas with the reactor and the catalyst, and prolongs the retention time of the pollution gas in the reactor, so that the air purification is more thorough, and the purpose of purifying the air is completed. According to the device, high-temperature-resistant foamed plastic is used for loading a catalyst, and different catalysts can be loaded to treat different types of waste gas. The device is suitable for home environment air purification, pollutants such as formaldehyde, benzene and second-hand smoke in the air can be effectively removed, the indoor air quality is improved, and a healthier and more comfortable breathing environment is provided for a user.

Description

Technical Field

[0001] The present invention belongs to the field of air simplification and relates to a circulating DBD cooperative catalytic air purification device and method. Background Art

[0002] With the development of the economy, people's yearning for a better life is becoming stronger and they pay more attention to the air problems in the home environment. The functions of air purifiers are gradually developing towards diversification and personalization. Most of the existing air purifiers integrate functions of removing gaseous pollutants such as formaldehyde, toluene, second-hand smoke, and microbial pollutants such as bacteria and viruses. More attention is also paid to the purification efficiency of indoor air purification technologies. The existing air purifiers mainly adopt passive purification technologies and active purification technologies; passive ones include filter technology and activated carbon adsorption technology. The former cannot remove gaseous pollutants such as formaldehyde and benzene, and the latter has a limited adsorption capacity, is easy to saturate, and the adsorbed pollutants may be released again after saturation, causing secondary pollution. Active ones include negative ion technology and photocatalyst technology. Negative ion technology combines released negative ions with pollutants in the air to make them settle or be adsorbed, but the generation of negative ions may be accompanied by the production of ozone, and too high ozone concentration will cause harm to human health. Photocatalyst technology uses photocatalytic reactions to decompose harmful gases and bacteria, but requires ultraviolet irradiation and is prone to generate ozone.

[0003] Plasma, also called plasma, is the fourth state of matter. Plasma can be divided into thermal plasma and non-thermal plasma. Thermal plasma, also known as equilibrium plasma, has an internal electron temperature close to that of heavy particles, usually above 10 4 K, with a higher energy density. Non-thermal plasma, also known as non-equilibrium plasma, has an electron temperature much higher than that of heavy particles, and the overall temperature is relatively low or even close to room temperature, is easy to generate and has high chemical activity. Non-thermal plasma contains a large number of active particles such as high-energy electrons, excited atoms, free radicals, etc. These active particles can carry out a series of physical and chemical reactions with reaction gas molecules. Therefore, non-thermal plasma has broad prospects in the fields of treating volatile organic compounds and malodorous gases.

[0004] Dielectric barrier discharge (DBD) is a high-voltage discharge between two electrodes separated by an insulating dielectric barrier layer. When a voltage is applied to the two electrodes, a current is generated in the space. Its advantages are a wide pressure range, a wide discharge frequency range, a simple structure, and uniform and stable discharge. At present, many emerging plasma treatment technologies have emerged, including cooperative catalyst treatment technology. However, there are problems such as incomplete contact between the catalyst and the gas and the inability of traditional reactors to handle the large air flow in practical applications. Summary of the Invention

[0005] 1. Technical problems to be solved: Design a DBD device that can fully cooperate with the catalyst and efficiently process the mixed gas.

[0006] 2. Technical solution: To solve the above problems, the present invention provides a circulating DBD cooperative catalytic air purification device, including a housing. A DBD reactor group is built in the housing. The DBD reactor group has a plurality of three-electrode coaxial DBD reactors. The three-electrode dielectric barrier discharge reactors are connected in series. The second air outlet of the previous three-electrode dielectric barrier discharge reactor is connected to the second air inlet of the next three-electrode dielectric barrier discharge reactor. The second air outlet of the last three-electrode dielectric barrier discharge reactor and the second air inlet of the first three-electrode dielectric barrier discharge reactor are connected to form a cycle. The second air outlet of the last three-electrode dielectric barrier discharge reactor is connected to the first air outlet of the air purification device. The three-electrode coaxial DBD reactor includes a coaxial glass outer tube and a glass inner tube. A spiral electrode is wound around the outer surface of the glass outer tube. A cylindrical high-voltage electrode is arranged between the glass outer tube and the glass inner tube. A rod-shaped electrode is arranged inside the glass inner tube. The lower end of the glass outer tube is fixed on a partition in the housing. There is a gap between the lower end of the glass inner tube and the partition. The upper end passes through the cover plate of the housing and is connected to a sealing fixed plug. One end of the rod-shaped electrode is fixed on the sealing fixed plug. The first air inlet of the air purification device is arranged above the housing. An air inlet fan is provided at the first air inlet of the air purification device. The second air inlet of the three-electrode coaxial DBD reactor is at the sealing fixed plug, and the second air outlet is arranged on the side above the glass outer tube.

[0007] It also includes a tail gas detector. The first detector air inlet of the tail gas detector is connected to the last three-electrode coaxial DBD reactor in the DBD reactor group. The first detector air outlet of the tail gas detector is connected to the first air outlet of the air purification device.

[0008] The tail gas detector further includes a second detector air inlet and a second detector air outlet. The second detector air inlet is connected to the first air inlet of the air purification device. The second detector air outlet is connected to the air inlet of the first three-electrode coaxial DBD reactor in the DBD reactor group.

[0009] It also includes a control system, which is arranged inside the exhaust gas detector. When the concentration of gaseous pollutants entering through the first air inlet of the air purification device is lower than the set threshold value, the first detector air outlet is opened, the gas is discharged through the first air outlet of the air purification device, and the second air inlet of the first three-electrode coaxial DBD reactor in the DBD reactor group is closed; when the concentration of pollutants contained in the gas after being processed by the last three-electrode coaxial DBD reactor in the DBD reactor group is lower than the set threshold value, the first detector air outlet is opened; if it is greater than the set threshold value, the first detector air outlet is closed, and the gas enters the interior of the first three-electrode coaxial DBD reactor in the DBD reactor group through the second detector air outlet to start the second round of treatment.

[0010] A funnel-shaped air inlet channel is provided between the air inlet fan and the first air inlet of the air purification device.

[0011] There are four of the three-electrode dielectric barrier discharge reactors.

[0012] A power supply module is also provided below the partition board. The power supply is alternating current, and the alternating current is adjusted to a suitable voltage through a power adapter to supply power to the device.

[0013] The present invention also provides a circulating DBD co-catalytic air purification device, and the circulating DBD co-catalytic air purification device described above is used.

[0014] 3. Beneficial effects: The present invention uses four mutually connected-in-series three-electrode dielectric barrier discharge (DBD) reactors as the core of the device. The air outlet of the previous reactor is connected to the air inlet of the subsequent reactor, so that the polluted gas is processed in multiple reactors to achieve the purpose of thoroughly purifying the air and reducing ozone. In addition, the device also adopts a two-stage reaction. In the first-stage reaction, the polluted gas enters the inner layer of the reactor through the air inlet fan and the pressurized air inlet channel, and after being co-processed, it is discharged from the tail end of the inner layer glass tube, and the second-stage reaction is carried out in the outer layer glass tube. The three-electrode segmented treatment greatly increases the contact area between the pollutants in the gas and the discharge plasma and the catalyst, and also increases the residence time of the pollutants in the gas in the reactor, making the air purification more thorough and achieving the purpose of purifying the air. In addition, the device also uses high-temperature resistant foam plastics to load the catalyst. The foam plastics have high porosity and large specific surface area, which can provide more active sites for the catalyst, thereby improving the catalytic efficiency. It has strong adaptability and can load different catalysts to treat different types of waste gas. Description of the Drawings

[0015] Figure 1 It is a schematic diagram of the circulating DBD co-catalytic air purification device.

[0016] Figure 2It is a cross-sectional view of a circulating DBD cooperative catalytic air purification device.

[0017] Figure 3 It is a top view of the air purification device.

[0018] Figure 4 It is a structural diagram of the middle layer of the air purification device.

[0019] Figure 5 It is a top view of the middle layer of the air purification device.

[0020] Figure 6 It is a schematic diagram of the intake fan.

[0021] Figure 7 It is a schematic diagram of the funnel-shaped intake duct.

[0022] Figure 8 It is a schematic diagram of the DBD reactor group.

[0023] Figure 9 It is a schematic diagram of the gas detector of the air purification device.

[0024] Figure 10 It is a schematic diagram of the three-electrode DBD reactor.

[0025] Figure 11 It is an assembly drawing of the three-electrode coaxial DBD reactor.

[0026] Figure 12 It is a schematic diagram of the rod electrode fixing pin.

[0027] Figure 13 It is a schematic diagram of the outer glass dielectric tube.

[0028] Figure 14 It is the device operation flow chart Explanation of reference numerals: 1. Intake fan; 2. Device housing; 3. Air outlet; 4. Funnel-shaped intake duct; 5. Three-electrode coaxial DBD reactor; 501. Rod electrode; 502. Fixing pin; 503. Inner glass tube; 504. High-voltage electrode; 505. Load catalyst foam; 506. Bottom-sealed glass outer tube; 507. Spiral electrode; 6. Tail gas detector; 601. First detector intake port; 602. Second detector intake port; 603. First detector outlet port; 604. Second detector outlet port; 7. Power supply module; 8. Gas pipeline; 801. First gas pipeline; 802. Second gas pipeline; 803. Third gas pipeline; 804. Fourth gas pipeline; 805. Fifth gas pipeline; 9. Sealing fixed plug. Detailed implementation manners

[0029] The present invention will be described in detail below by taking a DBD reactor group with 4 three-electrode coaxial DBD reactors as an example.

[0030] As Figure 1 shown in the left figure, the air purification device can be divided into three parts, namely the upper intake fan 1, the middle-layer pressurization and circulation system, and the lower reactor group. The device housing 2 is mainly composed of the intake fan 1, the plastic housing 2, and the first air outlet 3 of the air purification device.

[0031] As Figure 1 shown in the right figure cross-section, the five core parts inside the device from top to bottom are the intake fan 1, the funnel-shaped intake duct 4, the three-electrode coaxial DBD reactor 5, the tail gas detector 6, and the power module 7. The funnel-shaped intake duct 4 is a pressurized intake duct designed using Bernoulli's principle to ensure the flow of gas in the pipeline. In addition, the lower partition of the three-electrode coaxial DBD reactor separates the reaction chamber from the outside world, preventing the spiral electrode 507 outside the reactor from contacting the air.

[0032] As Figure 2 shown in the top view of the entire device, in one embodiment, the overall length of the device is about 130 - 140 mm, the width is about 130 - 140 mm, and the height is about 180 - 200 mm.

[0033] The middle layer of the air purification device is as Figure 3 shown. After the gas is pressurized by the funnel-shaped intake duct 4, it enters each reactor for treatment through the gas pipeline 8. The gas pipeline is connected to the intake port on the sealing fixed plug 9 and the second air outlet on the side wall of the glass outer tube 506 of the three-electrode coaxial DBD reactor.

[0034] The gas flow process is as Figure 4 、 Figure 8 shown. The pressurized polluted gas enters the tail gas detection system through the first detector intake port 601 of the tail gas detector 6. The unqualified gas enters the first two-stage DBD reactor for degradation treatment through the first gas pipeline 801 from the first detector outlet 603, and then enters the second reactor through the second gas pipeline 802, and so on. The gas finally enters the fourth reactor through the third gas pipeline 803 and the fourth gas pipeline 804. The gas treated by the four reactors enters the tail gas detector 6 through the fifth gas pipeline 805. If the degradation is completed, it is discharged up to standard. If there are still pollutants remaining, it enters the first two-stage DBD reactor for treatment again.

[0035] Figure 5 Shown is the schematic diagram of the intake fan, Figure 6 and the schematic diagram of the funnel-shaped intake duct. According to Bernoulli's principle and using the flow characteristics of the gas, the two are combined to form a pressurization system.

[0036] In one embodiment, the intake fan is 130 - 140 mm in length, 130 - 140 mm in width, and 20 - 30 mm in height; the funnel-shaped intake duct has a diameter of approximately 100 - 110 mm and a height of 50 - 60 mm. As Figure 4 shown, when the polluted gas is blown into the funnel-shaped intake duct by the intake fan, its flow rate gradually decreases. According to Bernoulli's equation, the static pressure of the gas will increase correspondingly. When the gas reaches the end of the intake duct, its pressure is greater than that of the gas just blown in, finally achieving the effect of physical pressurization. The pressurized gas can easily complete the circulation in the system without an additional negative pressure system. At the same time, the decrease in flow rate is also beneficial to increasing the residence time of the gas in the reactor.

[0037] The internal structure of the air purification device is as Figure 7 shown, from top to bottom are the funnel-shaped intake duct 4, the gas pipeline 8, the sealing fixed plug 9, the upper cover plate, the coaxial DBD reactor 5, the tail gas detector 6, the partition plate, and the power module 7.

[0038] As Figure 8 shown in the schematic diagram of the gas detector of the air purification device, the gas containing pollutants enters the tail gas detector 6 through the first detector intake port 601, and the unqualified gas enters the circulating reactor through the first detector outlet port 603. The gas containing pollutants undergoes the process as Figure 4 shown. After the treatment is completed, the gas enters the tail gas detector 6 through the fifth gas pipeline 805 from the second detector intake port 602 for detection. If the degradation is completed, it is discharged up to standard through the second detector outlet port 604. If there are still pollutants remaining, it enters the reactor for treatment again. The size of the detector removing the pipeline is approximately 30 - 40 mm in length, 40 - 50 mm in width, and 90 - 100 mm in height.

[0039] As Figure 9 shown, it is a schematic diagram of a three-electrode coaxial DBD reactor. As Figure 10 、 11 、shown in 12, the structure of this reactor is a three-electrode coaxial DBD reactor with a two-stage reaction, which is composed of the outermost spiral electrode 507, the glass outer tube 506 with a second outlet on the side, the high-voltage electrode 504, the glass inner tube 503, and the rod-shaped electrode 501. In one embodiment, the high-temperature resistant load catalyst foam plastic 505 is located between the glass outer tube 506 and the high-voltage electrode 504.

[0040] In one embodiment, as Figure 10 、 11 shown, the fixing pin 502 fixes the rod-shaped electrode on the glass inner tube 503, and at the same time its hollow design does not affect the flow of gas in the reactor.

[0041] As Figure 10As shown, the top is a sealed fixed plug 9 to ensure that the reactor is airtight. As Figure 12 shown, it is the glass outer tube of the coaxial DBD reactor, with an air outlet on the side to facilitate the gas after the reaction to enter the next reactor or detector. The diameter of this coaxial DBD reactor is about 30 - 35 mm, and the length is about 160 - 170 mm.

[0042] As Figure 13 shown, it is the flow chart of the polluted gas entering the air purification device and being degraded under the synergistic catalysis of plasma. This device combines dielectric barrier discharge plasma with photocatalyst and air purification to form a new type of circulating DBD synergistic catalytic air purification device. The core of this device is as Figure 9 shown, a group of four three - electrode coaxial DBD reactors. A single reactor consists of a ground - high - ground three - electrode structure, as Figure 10 shown. In the center is a stainless - steel metal rod - shaped electrode fixed by a fixing pin as the ground electrode, the cylindrical electrode is in the middle as the high - voltage electrode 504, and the outermost is the spiral electrode 507 as the ground electrode; the glass inner tube 503 and the glass outer tube 506 in the figure act as the barrier medium. Among them, the high - temperature resistant foam plastic 505 contains many pores for loading the catalyst to achieve DBD synergistic catalytic air purification.

[0043] This device introduces a tail gas detection system, as Figure 8 shown, to detect the purified gas. If the gas meets the standards, it is discharged through the air outlet at the lower end. If not, it enters the reactor again through the air inlet for thorough purification. This device also designs a pressurized circulating air supply system, as Figure 3 shown, the polluted gas is blown into the funnel - shaped 4 air inlet by the intake fan. Since the air inlet gradually narrows, the gas is compressed. When the gas reaches the end of the air inlet, its pressure is greater than the gas just blown in, finally achieving the effect of physical pressurization. The pressurized gas can easily complete the circulation in the system without an additional negative pressure system.

[0044] A single reactor also adopts a three - electrode two - stage reaction, which greatly increases the contact area between the polluted gas and the reactor and the catalyst, and also increases the residence time of the polluted gas in the reactor, making the air purification more thorough. As Figure 9 、 10 shown, pollutant molecules such as formaldehyde, hydrogen sulfide, and ammonia in the air enter the glass inner tube 503 through the first air inlet after pressurization to participate in the first - stage reaction. Subsequently, the gas after the first - stage reaction is discharged from the tail end of the glass inner tube and enters the second - stage reaction. The second stage is located between the glass inner tube and the outer tube and is equipped with high - temperature resistant foam plastic loaded with catalyst. The gas containing pollutants flows through it and is degraded under the synergistic action of plasma and catalyst.

[0045] The present invention also provides a circulating DBD collaborative catalytic air purification device. Using the circulating DBD collaborative catalytic air purification device includes the following steps: Step S01: Turn on the intake fan 1, and pass the gas to be treated through the funnel-shaped intake duct 4 into the tail gas detector 6. If the concentration of the gas is less than the set value, open the second detector air outlet 604, and discharge the gas from the first air outlet 3 of the air purification device. If the concentration of the gas is greater than the set value, proceed to the next step.

[0046] Step S02: The gas enters the inner glass tube 503 of the first three-electrode dielectric barrier discharge reactor 5 in series for treatment.

[0047] After being treated in the inner glass tube 503, the gas enters the space between the outer glass tube 506 and the inner glass tube 503. After treatment, it enters the inner glass tube 503 of the next three-electrode dielectric barrier discharge reactor 5 for treatment, and so on.

[0048] After the gas is treated by the last three-electrode dielectric barrier discharge reactor 5, it enters the tail gas detector 6. If the concentration of the gas is less than the set value, open the second detector air outlet 604, and discharge the gas from the first air outlet 3 of the air purification device. If the gas concentration is greater than the set value, enter Step S02 and cycle in this way.

Claims

1. A circulating DBD collaborative catalytic air purification device, comprising a housing (2), characterized in that: The outer shell (2) is internally provided with a DBD reactor group, and the DBD reactor group has a plurality of three - electrode coaxial DBD reactors (5). The three - electrode dielectric barrier discharge reactors (5) are connected in series. The second air outlet of the previous three - electrode dielectric barrier discharge reactor (5) is connected to the second air inlet of the next three - electrode dielectric barrier discharge reactor (5). The second air outlet of the last three - electrode dielectric barrier discharge reactor (5) is connected to the second air inlet of the first three - electrode dielectric barrier discharge reactor (5) to form a cycle. The second air outlet of the last three - electrode dielectric barrier discharge reactor (5) is connected to the first air outlet (3) of the air purification device. The three - electrode coaxial DBD reactor (5) includes a coaxial outer glass dielectric tube (13) and an inner glass dielectric tube (16). A spiral electrode (12) is wound around the outer surface of the outer glass dielectric tube (13). A cylindrical high - voltage electrode (17) is arranged between the outer glass dielectric tube (13) and the inner glass dielectric tube (16). A rod - shaped electrode (14) is arranged inside the inner glass dielectric tube (16). The lower end of the outer glass dielectric tube (13) is fixed on a partition in the outer shell (2). There is a gap between the lower end of the inner glass dielectric tube (14) and the partition. The upper end passes through the cover plate of the outer shell (2) and is connected to a sealing fixed plug (9). One end of the rod - shaped electrode (14) is fixed on the sealing fixed plug (9). The first air inlet of the air purification device is arranged above the outer shell (2). An intake fan (1) is provided at the first air inlet of the air purification device. The second air inlet of the three - electrode coaxial DBD reactor (5) is at the sealing fixed plug (9), and the second air outlet is arranged on the side above the outer glass dielectric tube (13).

2. The circulating DBD collaborative catalytic air purification device according to claim 1, characterized in that: It further includes a tail gas detector (6). The first detector air inlet (601) of the tail gas detector (6) is connected to the last three - electrode coaxial DBD reactor (5) in the DBD reactor group. The first detector air outlet (11) of the tail gas detector (6) is connected to the first air outlet (3) of the air purification device.

3. The circulating DBD co-catalytic air purification device according to claim 2, wherein: The tail gas detector (6) further includes a second detector air inlet (10) and a second detector air outlet (602). The second detector air inlet (10) is connected to the first air inlet of the air purification device. The second detector air outlet (602) is connected to the air inlet of the first three - electrode coaxial DBD reactor (5) in the DBD reactor group.

4. The circulating DBD co-catalytic air purification device according to claim 3, characterized in that: It further includes a control system, which is arranged inside the exhaust gas detector (6). When the concentration of gaseous pollutants entering through the first air inlet of the air purification device is lower than the set threshold value, the first detector air outlet (11) is opened, the gas is discharged through the first air outlet (3) of the air purification device, and the second air inlet of the first three-electrode coaxial DBD reactor (5) in the DBD reactor group is closed; when the concentration of pollutants contained after being processed by the last three-electrode coaxial DBD reactor (5) in the DBD reactor group is lower than the set threshold value, the first detector air outlet (11) is opened, and if it is greater than the set threshold value, the first detector air outlet (11) is closed, and the gas enters the interior of the first three-electrode coaxial DBD reactor (5) in the DBD reactor group through the second detector air outlet (602) to start the second round of treatment.

5. The circulating DBD co-catalytic air purification device according to any one of claims 1-4, characterized in that: A funnel-shaped air inlet channel (4) is provided between the air inlet fan (1) and the first air inlet of the air purification device.

6. The circulating DBD co-catalytic air purification device according to any one of claims 1-4, characterized in that: A high-temperature resistant supported catalyst foam plastic (18) is provided between the outer glass dielectric tube (13) and the high-voltage electrode (17).

7. The circulating DBD co-catalytic air purification device according to any one of claims 1-4, characterized in that: There are four of the three-electrode dielectric barrier discharge reactors (5).

8. The circulating DBD collaborative catalytic air purification device according to any one of claims 1-4, characterized in that: A power supply module (7) is further provided below the partition board. The power supply is alternating current, and the alternating current is adjusted to a suitable voltage through a power adapter to supply power to the device.

9. A circulating DBD cooperative catalytic air purification device, using the circulating DBD cooperative catalytic air purification device as described in any one of claims 1-7, comprising the following steps: Step S01: Turn on the air inlet fan (1), and let the gas to be processed enter the exhaust gas detector (6) through the funnel-shaped air inlet channel (4). If the concentration of the gas is less than the set value, open the first detector air outlet (11), and discharge the gas from the first air outlet (3) of the air purification device. If the concentration of the gas is greater than the set value, proceed to the next step; Step S02: The gas enters the inner glass dielectric tube (16) of the first series-connected three-electrode dielectric barrier discharge reactor (5) for treatment; Step S03: After being processed by the inner glass dielectric tube (16), the gas enters the space between the outer glass dielectric tube (13) and the inner glass dielectric tube (16), and after being processed, it enters the inner glass dielectric tube (16) of the next three-electrode dielectric barrier discharge reactor (5) for treatment, and so on; Step S04: After the gas is processed by the last three-electrode dielectric barrier discharge reactor (5), it enters the exhaust gas detector (6). If the concentration of the gas is less than the set value, open the first detector air outlet (11), and discharge the gas from the first air outlet (3) of the air purification device. If the gas concentration is greater than the set value, proceed to Step S02, and so on in a cycle.

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