A waste gas treatment device and its application

Abstract

The present invention belongs to the field of environmental protection, and in particular, relates to a waste gas treatment device and its application. The waste gas treatment device provided by the present invention includes: a waste gas treatment channel; the waste gas treatment channel has a plurality of plasma injection holes along the two side walls opposite to its axis perpendicular to the direction of waste gas movement, and the positions of the plasma injection holes on the two side walls are symmetrical to each other; each of the plasma injection holes is provided with a semi-circular tube baffle at the gas outlet end; the diameter of the semi-circular tube baffle is larger than the aperture of the plasma injection hole; an injection-type low-temperature plasma generator connected to the gas inlet end of the plasma injection hole; and a catalyst layer arranged in the waste gas treatment channel; along the direction of waste gas movement, the catalyst layer is located downstream of the plasma injection hole. The waste gas treatment equipment provided by the present invention has high degradation rate, good stability, high plasma utilization rate, and excellent mixing effect, and has a very broad market prospect.

Description

Technical Field

[0001] The invention belongs to the field of environmental protection, and in particular relates to a waste gas treatment device and an application thereof. Background Art

[0002] Many industrial production processes, such as tobacco processing, sewage treatment, and food processing wastewater treatment, will produce odorous gases containing low concentrations of VOCs. These odors often include VOCs, inorganic substances, hydrogen sulfide, ammonia, alcohol ethers and other components. If they diffuse into the surrounding atmosphere, they will endanger the health of residents and cause discomfort, resulting in frequent environmental complaints caused by industrial emission odor problems. High-efficiency odor removal technology has gradually received more and more attention.

[0003] Low-temperature plasma technology is an emerging method for treating odorous gases containing low concentrations of VOCs. Traditional low-temperature plasma technology places a low-temperature plasma generator in odorous gases containing low concentrations of VOCs. Under normal temperature and pressure conditions, a large number of high-energy electrons, hydroxyl and oxygen free radicals, ozone and other active particles with strong oxidizing properties can be generated, causing the VOCs odor molecules to ionize and dissociate, and then triggering a series of complex physical and chemical reactions, converting complex macromolecules (VOCs) pollutants into non-toxic or low-toxic small molecules. This technology has been widely used due to its many advantages such as convenient operation and management and simple process flow.

[0004] In recent years, injection-type low-temperature plasma technology has also been widely studied and applied. For example, the patent with publication number CN103055674A discloses an injection-type low-temperature plasma waste gas treatment system, including a fan, an air filter, a heater, a low-temperature plasma high-pressure reaction box, an electric control cabinet and an integrated adapter connected to the waste gas collection pipe. The low-temperature plasma generated by the fan is injected into the low-temperature plasma high-pressure reaction box and then mixed with the original waste gas collection pipe through a single-side injection integrated adapter; the patent with announcement number CN205109348U discloses an injection-type low-temperature plasma reaction device, including a low-temperature plasma generator, a venturi reaction chamber, an air purifier, etc., and the injection of plasma is achieved through a venturi structure. However, these injection-type low-temperature plasma technologies currently generally have problems such as limited degradation rate, poor stability, and poor injection effect leading to plasma annihilation, which need to be solved urgently. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a waste gas treatment equipment and application thereof. The waste gas treatment equipment provided by the present invention has a high degradation rate, good stability, high plasma utilization rate and excellent mixing effect.

[0006] The present invention provides an exhaust gas treatment device, comprising:

[0007] Exhaust gas treatment channel;

[0008] The exhaust gas treatment channel has a plurality of plasma injection holes formed on the two side walls opposite to each other along the axis thereof, perpendicular to the direction of exhaust gas movement, and the positions of the plasma injection holes formed on the two side walls are symmetrical to each other; a semicircular tube baffle is provided at the gas outlet end of each plasma injection hole; the diameter of the semicircular tube baffle is larger than the aperture of the plasma injection hole, the bottom end of the semicircular tube baffle is fixed to the inner wall of the exhaust gas treatment channel, and the top end points to the plasma injection hole symmetrical to the corresponding plasma injection hole; the convex surface of the semicircular tube baffle is the windward surface;

[0009] An injection-type low-temperature plasma generating device connected to the gas inlet end of the plasma injection hole;

[0010] and a catalyst layer disposed in the exhaust gas treatment channel; along the exhaust gas movement direction, the catalyst layer is located downstream of the plasma injection hole.

[0011] Preferably, the low-temperature plasma generator of the injection-type low-temperature plasma generating device is a double-dielectric barrier discharge reactor.

[0012] Preferably, the semi-circular tube-shaped baffles arranged in the exhaust gas treatment channel have at least two different lengths, and the lengths of the semi-circular tube-shaped baffles at adjacent and / or symmetrical plasma injection holes are different.

[0013] Preferably, the semicircular tube-shaped baffles arranged in the exhaust gas treatment channel are composed of semicircular tube-shaped baffles of two lengths, and the semicircular tube-shaped baffles at adjacent and symmetrical plasma injection holes are arranged alternately in length.

[0014] Preferably, the concave surface of the semicircular tube-shaped baffle is covered with an insulating layer.

[0015] Preferably, the material of the insulating layer is ceramic.

[0016] Preferably, along a direction perpendicular to the movement of the exhaust gas, the cross-section of the exhaust gas treatment channel is square.

[0017] Preferably, the catalyst filled in the catalyst layer uses honeycomb ceramics as a carrier and a complex of a noble metal element and a transition metal oxide as an active component.

[0018] The present invention provides a waste gas treatment method, which is carried out in the waste gas treatment equipment described in the above technical solution, comprising the following steps:

[0019] Passing the odorous waste gas into the waste gas inlet of the waste gas treatment channel, and starting the low-temperature plasma generator of the injection-type low-temperature plasma generator, so that the generated low-temperature plasma is injected into the waste gas treatment channel through the plasma injection hole;

[0020] The odorous waste gas flows in the waste gas treatment channel and reacts with the injected low-temperature plasma, and then enters the catalyst layer for catalytic degradation to obtain purified gas.

[0021] Preferably, the flow rate of the odorous waste gas in the waste gas treatment channel is 5 to 14 m / s;

[0022] The flow rate of the low-temperature plasma in the waste gas treatment channel is 15 to 30 m / s.

[0023] Compared with the prior art, the present invention provides an exhaust gas treatment device and its application. The exhaust gas treatment device provided by the present invention comprises: an exhaust gas treatment channel; the exhaust gas treatment channel has a plurality of plasma injection holes opened on the two side walls opposite to the axis thereof perpendicular to the direction of exhaust gas movement, and the positions of the plasma injection holes opened on the two side walls are symmetrical to each other; a semicircular tube baffle is provided at the gas outlet end of each plasma injection hole; the diameter of the semicircular tube baffle is larger than the aperture of the plasma injection hole, the bottom end of the semicircular tube baffle is fixed to the inner wall of the exhaust gas treatment channel, and the top end points to the plasma injection hole symmetrical to the corresponding plasma injection hole; the convex surface of the semicircular tube baffle is the windward surface; an injection-type low-temperature plasma generator connected to the air inlet end of the plasma injection hole; and a catalyst layer arranged in the exhaust gas treatment channel; along the direction of exhaust gas movement, the catalyst layer is located downstream of the plasma injection hole. The main working process of the equipment during operation is as follows: air passes through the injection-type low-temperature plasma generator to form a high-concentration low-temperature plasma, and then enters the exhaust gas treatment channel through the symmetrically arranged plasma injection holes, and is fully mixed and reacted with the odorous exhaust gas in the exhaust gas treatment channel to promote the cracking of odorous components in the odorous exhaust gas; then the reacted mixed gas enters the catalyst layer, and further degradation reaction occurs under the action of the catalyst to achieve efficient removal of odorous components in the odorous exhaust gas. In the device provided by the present invention, the plasma generator is not in direct contact with the original exhaust gas, which improves the stability of the plasma reactor; at the same time, the symmetrically designed plasma injection hole and the semi-circular tube baffle arranged at the outlet end of the plasma injection hole prevent the plasma from concentrating on the edge of the downstream flue, resulting in uneven mixing, prolonging the life of free radicals, ozone, and high-energy electrons in the plasma, and promoting the full mixing and contact of plasma with odorous gases; further, through the setting of the catalyst layer, the porous structure and active sites of the catalyst can be used to effectively utilize not only the transient active groups such as ·OH and ·O generated by the plasma, but also the O3 generated by the low-temperature plasma can further degrade the organic pollutant molecules in the catalyst layer, further improving the odor treatment effect. In summary, the exhaust gas treatment equipment provided by the present invention has a high degradation rate, good stability, high plasma utilization rate, and excellent mixing effect, and has a very broad market prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention 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 embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0025] Figure 1 is a front view of an exhaust gas treatment device provided by an embodiment of the present invention;

[0026] Figure 2 It is a left side view of the exhaust gas treatment equipment provided by an embodiment of the present invention;

[0027] Figure 3 It is a partial enlarged view of the waste gas treatment equipment provided by an embodiment of the present invention at the plasma injection hole;

[0028] Figure 4 It is a diagram showing the simulation result of the plasma velocity distribution of the flue gas channel section of the plasma in the waste gas treatment equipment provided by the embodiment of the present invention;

[0029] Figure 5 is a diagram of the simulation result of the concentration field of plasma in the gas flow section of the catalyst layer provided by an embodiment of the present invention;

[0030] Figure 6 It is a schematic structural diagram of a conventional low-temperature plasma implanter provided by the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The present invention provides an exhaust gas treatment device, comprising:

[0033] Exhaust gas treatment channel;

[0034] The exhaust gas treatment channel has a plurality of plasma injection holes formed on the two side walls opposite to each other along the axis thereof, perpendicular to the direction of exhaust gas movement, and the positions of the plasma injection holes formed on the two side walls are symmetrical to each other; a semicircular tube baffle is provided at the gas outlet end of each plasma injection hole; the diameter of the semicircular tube baffle is larger than the aperture of the plasma injection hole, the bottom end of the semicircular tube baffle is fixed to the inner wall of the exhaust gas treatment channel, and the top end points to the plasma injection hole symmetrical to the corresponding plasma injection hole; the convex surface of the semicircular tube baffle is the windward surface;

[0035] An injection-type low-temperature plasma generating device connected to the gas inlet end of the plasma injection hole;

[0036] and a catalyst layer disposed in the exhaust gas treatment channel; along the exhaust gas movement direction, the catalyst layer is located downstream of the plasma injection hole.

[0037] See also Figures 1 to 3 , Figure 1 is a front view of an exhaust gas treatment device provided by an embodiment of the present invention, Figure 2 is a left side view of the exhaust gas treatment equipment provided by an embodiment of the present invention, Figure 3 It is a local enlarged view of the waste gas treatment equipment provided by an embodiment of the present invention at the plasma injection hole (the left picture is a front view, and the right picture is a left view); wherein 1 is a waste gas treatment channel, 2 is a plasma injection hole, 3 is a semicircular tube baffle, 3-1 is a semicircular tube short baffle, 3-2 is a semicircular tube long baffle, 4 is an injection-type low-temperature plasma generating device, 4-1 is a low-temperature plasma generator, and 5 is a catalyst layer.

[0038] The waste gas treatment equipment provided by the present invention comprises a waste gas treatment channel 1, a plasma injection hole 2, a semicircular tube baffle 3, an injection type plasma generating device 4 and a catalyst layer 5.

[0039] In the waste gas treatment equipment provided by the present invention, the waste gas treatment channel 1 is a place where the odorous waste gas is mixed with the plasma for reaction and catalytic degradation, and a waste gas inlet is arranged at one end thereof and a gas outlet is arranged at the other end thereof. In the present invention, the shape of the cross section of the waste gas treatment channel 1 perpendicular to the direction of movement of the waste gas is preferably a square, and the side length of the cross section is preferably 200 to 500 mm, specifically 200 mm, 230 mm, 250 mm, 270 mm, 300 mm, 320 mm, 350 mm, 370 mm, 400 mm, 420 mm, 450 mm, 470 mm or 500 mm; the total length of the waste gas treatment channel 1 from the waste gas inlet to the gas outlet is preferably 5 to 10 m, specifically 5 m, 5.5 m, 6 m, 6.5 m, 7 m, 7.5 m, 8 m, 8.5 m, 9 m, 9.5 m or 10 m.

[0040] In the waste gas treatment equipment provided by the present invention, the plasma injection hole 2 is the entrance for the plasma to enter the inner cavity of the waste gas treatment channel 1, and the number of the plasma injection holes 2 is several; the several plasma injection holes 2 are opened on the two side walls of the waste gas treatment channel 1 along the axis thereof in a direction perpendicular to the movement of the waste gas, and the positions of the plasma injection holes 2 opened on the two side walls are symmetrical to each other. In the present invention, the aperture of the plasma injection hole 2 is preferably 10 to 50 mm, specifically 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm or 50 mm; the hole distance between two adjacent plasma injection holes 2 is preferably 20 to 100 mm, specifically 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm or 100 mm. In the present invention, the number of plasma injection holes 2 on a single side wall is preferably 10 to 50, specifically 10, 15, 18, 20, 25, 28, 30, 35, 38, 40, 45, 48 or 50. In the present invention, symmetrical bidirectional injection of low-temperature plasma can be achieved through symmetrically arranged plasma injection holes 2, which can not only greatly reduce the movement stroke and time of plasma generation, ensure the service life of active particles such as OH radicals, but also facilitate uniform mixing of plasma and original exhaust gas.

[0041] In the exhaust gas treatment equipment provided by the present invention, the semi-circular tube baffle 3 is arranged in the inner cavity of the exhaust gas treatment channel 1, located at the gas outlet end of each plasma injection hole 2, the diameter of the semi-circular tube baffle 3 is larger than the aperture of the plasma injection hole 2, the bottom end is fixed to the inner wall of the exhaust gas treatment channel 1, and the top end points to the plasma injection hole symmetrical to the corresponding plasma injection hole 2; the convex surface of the semi-circular tube baffle 3 is the windward surface, that is, the semi-circular tube baffle 3 blocks the first half of the arc of the corresponding plasma injection hole 2. In the present invention, the difference between the diameter of the semi-circular tube baffle 3 and the aperture of the plasma injection hole 2 is preferably 2 to 10 mm, specifically 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm. In the present invention, by setting the semicircular tube baffle 3, on the one hand, the direct impact of the incoming gas on the plasma can be blocked, preventing the plasma from concentrating on the edge of the downstream flue and causing uneven mixing; on the other hand, due to the use of a semicircular structure with a slightly larger diameter, the plasma annihilation effect caused by the contact between the plasma and the baffle tube wall can be well reduced.

[0042] In the exhaust gas treatment equipment provided by the present invention, the semicircular tube-shaped baffle 3 arranged in the exhaust gas treatment channel 1 preferably has at least two different lengths, and the lengths of the semicircular tube-shaped baffles 3 at adjacent and / or symmetrical plasma injection holes 2 are different; more preferably, the semicircular tube-shaped baffle 3 arranged in the exhaust gas treatment channel 1 is composed of semicircular tube-shaped baffles of two lengths, and the semicircular tube-shaped baffles 3 at adjacent and symmetrical plasma injection holes 2 are arranged in a staggered manner according to length, such as Figure 3 As shown, the semicircular tube baffles arranged in the exhaust gas treatment channel 1 are composed of a semicircular tube short baffle 3-1 and a semicircular tube long baffle 3-2, and the semicircular tube short baffles 3-1 and the semicircular tube long baffles 3-2 are arranged alternately at adjacent and symmetrical plasma injection holes 2; the length of the semicircular tube short baffle 3-1 is preferably 50 to 200 mm, specifically 50 mm, 70 mm, 100 mm, 120 mm, 150 mm, 170 mm or 200 mm; the length of the semicircular tube long baffle 3-2 is preferably 50 to 200 mm, specifically 50 mm, 70 mm, 100 mm, 120 mm, 150 mm, 170 mm or 200 mm. In the present invention, by adopting staggered arrangement of semicircular tubular baffles 3 of different lengths, it is more conducive to the full mixing of the injected plasma and the odorous exhaust gas, and improves the uniformity of the distribution of the plasma on the catalyst cross section, which is more conducive to the uniform mixing reaction with the exhaust gas and the subsequent catalytic reaction.

[0043] In the exhaust gas treatment equipment provided by the present invention, the concave surface (i.e., the inner surface) of the semicircular tube baffle 3 is preferably covered with an insulating layer; the material of the insulating layer is preferably ceramic; the thickness of the insulating layer is preferably 0.2 to 0.5 mm, specifically 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm or 0.5 mm. In the present invention, by providing an insulating layer, the annihilation loss of plasma can be further reduced.

[0044] In the waste gas treatment equipment provided by the present invention, the injection type low temperature plasma generator 4 is used to generate low temperature plasma and inject it into the plasma injection hole 2. One end of the injection type low temperature plasma generator 4 is provided with an air inlet, and a low temperature plasma generator 4-1 is provided in the cavity, and the other end is connected to the plasma injection hole 2. In the present invention, since the plasma injection hole 2 is symmetrically arranged on both sides of the wall of the waste gas treatment channel 1, it is preferred to set two injection type low temperature plasma generators 4, and each injection type low temperature plasma generator 4 is connected to the plasma injection hole 2 on one side of the wall of the waste gas treatment channel 1. In the present invention, the low temperature plasma generator 4-1 is preferably a double dielectric barrier discharge reactor, and more preferably a polar row double dielectric barrier discharge reactor with lower resistance.

[0045] In the exhaust gas treatment equipment provided by the present invention, the catalyst layer 5 is arranged in the exhaust gas treatment channel 1, and is located downstream of the plasma injection hole 2 along the direction of exhaust gas movement, and is used to catalytically degrade the gas that has completed the mixed reaction with the plasma. In the present invention, the shape of the cross section of the catalyst layer 5 perpendicular to the direction of exhaust gas movement is preferably a square, and the side length of the cross section is preferably 500-1000mm, specifically 500mm, 550mm, 600mm, 650mm, 700mm, 750mm, 800mm, 850mm, 900mm, 950mm or 1000mm; the thickness of the catalyst layer 5 is preferably 200-600mm, specifically 200mm, 250mm, 300mm, 350mm, 400mm, 450mm, 500mm, 550mm or 600mm. In the present invention, the catalyst filled in the catalyst layer 5 is preferably supported by honeycomb ceramics, and a complex of a noble metal element and a transition metal oxide is an active component; the noble metal element is preferably Pt; the loading amount of the noble metal element in the catalyst is preferably 0.1 to 1 wt%, specifically 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt% or 1 wt%; the transition metal oxide includes but is not limited to iron oxide. The loading amount of the iron oxide in the catalyst is preferably 0.5-2wt%, specifically 0.5wt%, 0.7wt%, 1wt%, 1.2wt%, 1.5wt%, 1.7wt% or 2wt%; the loading amount of the manganese oxide in the catalyst is preferably 1-3wt%, specifically 1wt%, 1.2wt%, 1.5wt%, 1.7wt%, 2wt%, 2.3wt%, 2.5wt%, 2.7wt% or 3wt%.

[0046] The present invention also provides a method for treating waste gas in the waste gas treatment equipment described in the above technical solution, comprising the following steps:

[0047] The odorous waste gas is introduced into the waste gas inlet of the waste gas treatment channel 1, and the low-temperature plasma generator 4-1 of the injection-type low-temperature plasma generating device 4 is started, and the generated low-temperature plasma is injected into the waste gas treatment channel 1 through the plasma injection hole 2;

[0048] The odorous waste gas flows in the waste gas treatment channel 1 and reacts with the injected low-temperature plasma, and then enters the catalyst layer 5 for catalytic degradation to obtain purified gas.

[0049] In the waste gas treatment method provided by the present invention, the waste gas is preferably an odorous gas containing VOCs; the flow rate of the odorous waste gas in the waste gas treatment channel 1 is preferably 5-14 m / s, specifically 5 m / s, 6 m / s, 7 m / s, 8 m / s, 9 m / s, 10 m / s, 11 m / s, 12 m / s, 13 m / s or 14 m / s; the flow rate of the low-temperature plasma in the waste gas treatment channel 1 is preferably 15-30 m / s, specifically 15 m / s, 16 m / s, 17 m / s, 18 m / s, 19 m / s, 20 m / s, 21 m / s, 22 m / s, 23 m / s, 24 m / s, 25 m / s, 26 m / s, 27 m / s, 28 m / s, 29 m / s or 30 m / s. In the present invention, the flow rate of the low-temperature plasma can be controlled by adjusting the aperture size of the plasma injection hole 2. By controlling the flow rate of the low-temperature plasma within the range of 15 to 30 m / s, the annihilation of the plasma can be effectively reduced and the utilization efficiency of the plasma can be improved.

[0050] In the exhaust gas treatment method provided by the present invention, the space velocity of the exhaust gas entering the catalyst layer 5 for catalytic degradation is preferably 8000 to 40000 h -1 , specifically 8000h -1 、10000h -1 、12000h -1 、15000h -1 、20000h -1 、25000h -1 、30000h -1 、35000h -1 or 40000h -1 .

[0051] The technical solution provided by the present invention improves the stability of the plasma reactor by preventing the plasma generator from directly contacting the original exhaust gas; at the same time, the symmetrically designed plasma injection hole and the semi-circular tube baffle arranged at the outlet end of the plasma injection hole prevent the plasma from concentrating on the edge of the downstream flue, resulting in uneven mixing, prolonging the life of free radicals, ozone, and high-energy electrons in the plasma, and promoting the full mixing and contact of the plasma with the odorous gas; further, by setting up the catalyst layer and utilizing the porous structure and active sites of the catalyst, not only can the transient active groups such as ·OH and ·O generated by the plasma be effectively utilized, but also the O3 generated by the low-temperature plasma can further degrade the organic pollutant molecules in the catalyst layer, further improving the odor control effect. In summary, the technical solution provided by the present invention has a high degradation rate, good stability, high plasma utilization rate, and excellent mixing effect, and has a very broad market prospect.

[0052] For the purpose of greater clarity, the invention is described in detail through the following examples.

[0053] Example 1

[0054] An injection type low temperature plasma catalytic odor treatment device, the structure of which is as follows Figures 1 to 3 As shown, it specifically includes: an exhaust gas treatment channel 1, a plasma injection hole 2, a semi-circular tube baffle 3, an injection type plasma generating device 4 and a catalyst layer 5.

[0055] In this embodiment, an exhaust gas inlet is provided at one end of the exhaust gas treatment channel 1, and an exhaust outlet is provided at the other end; the cross-sectional shape of the exhaust gas treatment channel 1 is a square (370mm×370mm); the total length of the exhaust gas treatment channel 1 from the exhaust gas inlet to the exhaust outlet is 6m.

[0056] In the present embodiment, a plurality of plasma injection holes 2 are opened on the two side walls of the exhaust gas treatment channel 1 opposite to each other along its axis in a direction perpendicular to the movement of the exhaust gas, and the positions of the plasma injection holes 2 opened on the two side walls are symmetrical with each other; in the present embodiment, the aperture diameter of the plasma injection hole 2 is 15 mm, the hole distance between adjacent holes is 25 mm, and the number of holes on a single side wall is 18.

[0057] In this embodiment, the semi-circular tube baffle 3 is arranged in the inner cavity of the exhaust gas treatment channel 1, located at the outlet end of each plasma injection hole 2, and the diameter of the semi-circular tube baffle 3 is 18 mm. Its bottom end is fixed to the inner wall of the exhaust gas treatment channel 1, and its top end points to the plasma injection hole symmetrical to the corresponding plasma injection hole 2; the convex surface of the semi-circular tube baffle 3 is the windward surface, that is, the semi-circular tube baffle 3 blocks the front half of the arc of the corresponding plasma injection hole 2. Figure 3 As shown, the semicircular tube baffles arranged in the exhaust gas treatment channel 1 are composed of a semicircular tube short baffle 3-1 and a semicircular tube long baffle 3-2. The length of the semicircular tube short baffle 3-1 is 100 mm, and the length of the semicircular tube long baffle 3-2 is 200 mm. The semicircular tube short baffles 3-1 and the semicircular tube long baffles 3-2 are alternately arranged at adjacent and symmetrical plasma injection holes 2.

[0058] In this embodiment, one end of the injection-type low-temperature plasma generating device 4 is provided with an air inlet, a low-temperature plasma generator 4-1 is provided in the cavity, and the other end is connected to the plasma injection hole 2. The low-temperature plasma generator 4-1 is a polar-row double-dielectric barrier discharge reactor with relatively low resistance.

[0059] In this embodiment, the catalyst layer 5 is arranged in the exhaust gas treatment channel 1, and is located downstream of the plasma injection hole 2 along the direction of exhaust gas movement; the cross-section of the catalyst layer 5 perpendicular to the direction of exhaust gas movement is 700mm×700mm, and the thickness of the catalyst layer 5 is 400mm; the catalyst filled in the catalyst layer 5 is supported by honeycomb ceramics, and the active components are formed by the precious metal element Pt, transition metal oxide FeOx, and MnOx. In the catalyst, the Pt loading is 0.5wt%, the FeOx loading is 1wt%, and the MnOx loading is 1.5wt%.

[0060] Example 2

[0061] The injection-type low-temperature plasma catalytic odor control equipment provided in Example 1 was subjected to a CFD simulation experiment using Fluent software, mainly focusing on a 5000m 3 / h The velocity field distribution and concentration field distribution of the exhaust gas treatment channel space are simulated, and the concentration uniformity is evaluated with the relative standard deviation of concentration as an indicator. The specific results are as follows Figures 4-5 As shown, Figure 4 is a diagram showing the simulation result of the plasma velocity distribution of the flue gas channel section of the plasma in the waste gas treatment equipment provided by the embodiment of the present invention. Figure 5 It is a diagram of the simulation results of the concentration field of plasma in the gas flow section of the catalyst layer provided by an embodiment of the present invention.

[0062] pass Figure 4 It is known that the plasma distribution of the injection-type low-temperature plasma catalytic odor control device provided in Example 1 is relatively uniform, and there is no obvious wall adhesion phenomenon, indicating that the plasma mixing effect is good. Figure 5 It can be seen that the relative deviation of the concentration on the cross-sectional area of ​​the catalyst layer of the injection-type low-temperature plasma catalytic odor control equipment provided in Example 1 is only 2.5%, indicating that the concentration uniformity of the equipment is good.

[0063] Comparative Example 1

[0064] An injection-type low-temperature plasma catalytic odor treatment device, which differs from the device described in Example 1 only in that the injection structure of the low-temperature plasma is different;

[0065] In this comparative example, the injection structure of the low temperature plasma is as follows Figure 6 As shown, Figure 6It is a structural schematic diagram of a traditional low-temperature plasma implanter provided by the present invention, wherein the left figure is a front view and the right figure is a left view; more specifically, the injection structure adopts symmetrical plasma injection pipes on the left and right sides, and the plasma is injected through three φ48mm pipes. The center of the pipe is a blocking structure, and there are two rows of plasma through holes on the leeward side of the pipe (12 φ15mm through holes in each pipe), and the injection direction of the plasma through holes is at a 45° angle with the flue gas flow.

[0066] While ensuring that the plasma injection velocity is the same as that in Example 2, a CFD simulation experiment is carried out on the injection-type low-temperature plasma catalytic odor control equipment provided in this comparative example. 3 / h The velocity field distribution and concentration field distribution of the exhaust gas treatment channel space were simulated, and the experimental results showed that the relative deviation of the concentration on the catalyst cross-sectional area was 7.1%.

[0067] Example 3

[0068] Taking deodorization efficiency as an indicator, the odor gas treatment effects of the equipment provided in Example 1 and Comparative Example 1 were evaluated respectively:

[0069] 1) Experimental conditions:

[0070] Exhaust gas type Food industry wastewater anaerobic tank waste gas Exhaust volume <![CDATA[4300m 3 / h]]> Odor value 5000~10000 (dimensionless) Injection power 4.5kW Catalyst space velocity <![CDATA[22000h -1 ]]>

[0071] 2) Experimental results of odor gas treatment using the device of the present invention:

[0072] project Injection power 4.5kW Original odor 5495 Odor after treatment 1738 Deodorization efficiency 68.4％

[0073] 3) Experimental results of traditional structure low temperature plasma implanter + catalysis:

[0074] project Injection power 4.5kW Original odor 5495 Odor after treatment 3090 Deodorization efficiency 43.8％

[0075] It can be seen that under the same power conditions, the comprehensive deodorization performance of the device using the structure described in Example 1 is improved by 25%.

[0076] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An exhaust gas treatment device, comprising: Exhaust gas treatment channel; The exhaust gas treatment channel has a plurality of plasma injection holes formed on the two side walls opposite to each other along the axis thereof, perpendicular to the direction of exhaust gas movement, and the positions of the plasma injection holes formed on the two side walls are symmetrical to each other; a semicircular tube baffle is provided at the gas outlet end of each plasma injection hole; the diameter of the semicircular tube baffle is larger than the aperture of the plasma injection hole, the bottom end of the semicircular tube baffle is fixed to the inner wall of the exhaust gas treatment channel, and the top end points to the plasma injection hole symmetrical to the corresponding plasma injection hole; the convex surface of the semicircular tube baffle is the windward surface; An injection-type low-temperature plasma generating device connected to the gas inlet end of the plasma injection hole; and a catalyst layer disposed in the exhaust gas treatment channel; along the exhaust gas movement direction, the catalyst layer is located downstream of the plasma injection hole.

2. The exhaust gas treatment equipment according to claim 1, characterized in that: The low-temperature plasma generator of the injection-type low-temperature plasma generating device is a double-medium barrier discharge reactor.

3. The exhaust gas treatment equipment according to claim 1, characterized in that: The semicircular tube-shaped baffles arranged in the exhaust gas treatment channel have at least two different lengths, and the lengths of the semicircular tube-shaped baffles at adjacent and / or symmetrical plasma injection holes are different.

4. The exhaust gas treatment equipment according to claim 3, characterized in that: The semicircular tube-shaped baffles arranged in the exhaust gas treatment channel are composed of semicircular tube-shaped baffles of two lengths, and the semicircular tube-shaped baffles at adjacent and symmetrical plasma injection holes are arranged in a staggered manner according to their lengths.

5. The exhaust gas treatment equipment according to claim 1, characterized in that: The concave surface of the semicircular tube-shaped baffle is covered with an insulating layer.

6. The exhaust gas treatment equipment according to claim 5, characterized in that: The material of the insulating layer is ceramic.

7. The exhaust gas treatment equipment according to claim 1, characterized in that: Along the direction perpendicular to the movement of the exhaust gas, the cross-section of the exhaust gas treatment channel is square.

8. The exhaust gas treatment equipment according to claim 1, characterized in that: The catalyst filled in the catalyst layer uses honeycomb ceramics as a carrier and a complex of a noble metal single substance and a transition metal oxide as an active component.

9. A method for treating waste gas, carried out in the waste gas treatment equipment according to claim 1, comprising the following steps: Passing the odorous waste gas into the waste gas inlet of the waste gas treatment channel, and starting the low-temperature plasma generator of the injection-type low-temperature plasma generator, so that the generated low-temperature plasma is injected into the waste gas treatment channel through the plasma injection hole; The odorous waste gas flows in the waste gas treatment channel and reacts with the injected low-temperature plasma, and then enters the catalyst layer for catalytic degradation to obtain purified gas.

10. The exhaust gas treatment method according to claim 9, characterized in that: The flow rate of the odorous waste gas in the waste gas treatment channel is 5 to 14 m / s; The flow rate of the low-temperature plasma in the waste gas treatment channel is 15 to 30 m / s.

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