A waste incineration flue gas denitration reaction device

Abstract

The application discloses a kind of waste incineration flue gas denitration reaction devices, belong to waste incineration flue gas purification technical field.The device includes reactor shell, shell is separated into multiple independent small compartments by horizontal partition, a independent discharge electrode is arranged in each small compartment.The cross section of discharge electrode is streamline, surface is provided with flow guide groove along length direction, and is coated with anti-ash coating.Each discharge electrode is connected to independent high-voltage power module, and each high-voltage power module independently controls the on-off and discharge intensity of corresponding electrode.The application eliminates vortex zone of electrode leeward by streamline cross section, flow guide groove guides airflow to flush electrode surface, and anti-ash coating reduces dust adhesion, which effectively prevents electrode ash deposition through the synergistic effect of the three;At the same time, each electrode is controlled by an independent power module, which can realize independent power-off maintenance of a single electrode without the need for whole machine shutdown, significantly improving the continuous operation capacity and denitration efficiency of the device.

Description

Technical Field

[0001] This invention belongs to the field of waste incineration flue gas purification technology, and particularly relates to a waste incineration flue gas denitrification reaction device. Background Technology

[0002] The flue gas produced during waste incineration contains a large amount of nitrogen oxides (NOx), which is one of the main sources of air pollution and must be treated before it can be released.

[0003] Currently, low-temperature plasma technology is an emerging technology in the field of denitrification of waste incineration flue gas. This technology generates low-temperature plasma through high-voltage discharge, and utilizes the high-energy active substances in the plasma to oxidize NOx in the flue gas into water-soluble NO2 or N2O5, which can then be removed by subsequent wet scrubbing. This technology does not require a high-temperature environment and is particularly suitable for the low temperature characteristics of waste incineration flue gas.

[0004] However, existing low-temperature plasma denitrification devices suffer from a prominent technical problem in practical applications: electrode ash accumulation. Waste incineration flue gas contains a large amount of dust, which gradually adheres to the electrode surface as it flows through the discharge electrodes. With prolonged operation, the ash layer on the electrode surface continuously thickens, leading to the following consequences:

[0005] First, the dust layer covering the electrode surface weakens the discharge intensity and reduces the amount of plasma generated.

[0006] Second, uneven discharge and local electric field distortion reduce the oxidation efficiency of NOx.

[0007] Third, when ash accumulation is severe, the machine needs to be shut down for cleaning, which affects the continuous operation of the incineration plant.

[0008] To address the aforementioned issues, several improvements have been implemented in the existing technology. For example, some solutions incorporate mechanical cleaning devices such as scrapers on the electrode surface to remove accumulated dust. However, these mechanical cleaning devices have moving parts, resulting in complex structures, and the scrapers themselves wear down and require periodic replacement, increasing maintenance costs. Other solutions utilize airflow purging for dust removal, but the purging airflow is insufficient to cover the entire electrode surface, limiting the cleaning effectiveness. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the existing technology and propose a waste incineration flue gas denitrification reaction device.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A waste incineration flue gas denitrification reactor includes a reactor shell and discharge electrodes disposed within the shell. The reactor shell has a vertical shell structure with a flue gas inlet at the bottom and a flue gas outlet at the top. Several layers of horizontal baffles are spaced apart along the height of the shell, dividing the interior into multiple vertically arranged independent compartments. Flue gas channels are formed in the horizontal baffles for flue gas passage. Each compartment contains an independent discharge electrode, which is vertically installed within the compartment and is not connected to any other discharge electrodes. The discharge electrode has a streamlined cross-section. Multiple guide grooves are formed along the length of the discharge electrode's surface. The surface of the discharge electrode is coated with an anti-ash accumulation coating. The device also includes multiple independent high-voltage power supply modules. Each discharge electrode in each compartment is connected to a separate high-voltage power supply module, and each high-voltage power supply module independently controls the on / off state and discharge intensity of its corresponding discharge electrode.

[0012] Preferably, the reactor shell is a vertical rectangular box.

[0013] Preferably, the cross-section of the discharge electrode is wing-shaped or teardrop-shaped, with its windward side being arc-shaped and its leeward side being tapered.

[0014] Preferably, the guide groove extends from the top to the bottom of the discharge electrode along the length of the electrode, and the direction of the guide groove is parallel to the flue gas flow direction.

[0015] Preferably, the cross-section of the guide channel is V-shaped.

[0016] Preferably, the anti-dust coating is a fluorocarbon resin coating, an organosilicon resin coating, or a ceramic coating.

[0017] Preferably, each compartment is also provided with an insulating support, and the upper and lower ends of the discharge electrode are fixed to the upper and lower partitions of the compartment respectively by the insulating support.

[0018] Preferably, the discharge electrodes in each compartment are arranged coaxially in the vertical direction.

[0019] The present invention has the following beneficial effects:

[0020] 1. This invention has excellent anti-dust accumulation effect. Through a streamlined cross-section eliminating the leeward vortex zone, a guide channel directing airflow to scour the electrode surface, and an anti-dust coating reducing dust adhesion, this triple mechanism works synergistically to effectively reduce dust deposition on the electrode surface, extending the electrode cleaning cycle. Compared to existing technologies that use mechanical cleaning devices such as scrapers, this invention does not involve moving parts, has a simpler structure, and eliminates the problems of mechanical wear and periodic replacement of vulnerable parts, resulting in higher reliability and lower maintenance costs.

[0021] 2. This invention requires no downtime for maintenance. By dividing the electrodes into multiple independent segments and configuring each segment with an independent power supply module, independent on / off control of each segment is achieved. When a segment of the electrode requires maintenance, simply disconnect the power supply to that segment; the other segments can still operate normally, and the entire device does not need to be shut down.

[0022] 3. The discharge intensity of each electrode segment of the present invention can be adjusted independently, and the energy consumption can be flexibly adjusted according to the actual parameters of the flue gas in each compartment, avoiding the energy waste caused by the unified power supply of all electrodes in the traditional solution. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall device structure proposed in this invention;

[0024] Figure 2 This is a schematic cross-sectional view of the overall device proposed in this invention;

[0025] Figure 3 This is a top view schematic diagram of the discharge electrode connection structure proposed in this invention;

[0026] Figure 4 This is a schematic diagram of the enlarged structure of the discharge electrode proposed in this invention;

[0027] Figure 5 The present invention proposes Figure 4 Enlarged structural diagram at point A in the middle.

[0028] In the diagram: 1. Reactor shell; 2. Flue gas inlet; 3. Flue gas outlet; 4. Horizontal baffle; 5. Flue gas passage; 6. Small compartment; 7. Discharge electrode; 8. Guide channel; 9. Anti-dust coating; 10. High voltage power module; 11. Insulating support; 12. Upper baffle; 13. Lower baffle. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0030] A waste incineration flue gas denitrification reactor includes a reactor shell 1. The reactor shell 1 has a vertical shell structure, with a flue gas inlet 2 at the bottom and a flue gas outlet 3 at the top. The reactor shell 1 can be a vertical rectangular box to facilitate the installation and layout of the internal components.

[0031] Several layers of horizontal baffles 4 are arranged at intervals along the height direction inside the reactor shell 1. There are two to five layers of horizontal baffles 4, dividing the interior of the shell into three to six independent small compartments 6 arranged vertically. Flue gas channels 5 are provided on the horizontal baffles 4 for the passage of flue gas. The flue gas channels 5 can be multiple through holes formed on the horizontal baffles 4, distributed around the installation positions of the discharge electrodes 7 within the small compartment 6. This arrangement allows the flue gas to pass uniformly through the horizontal baffles 4 into each small compartment 6, while ensuring the uniformity of the flow field around the electrodes.

[0032] Each compartment 6 contains an independent discharge electrode 7. The discharge electrode 7 is vertically installed within the compartment 6, and the discharge electrodes 7 in each compartment 6 are not connected to each other. Each compartment 6 also contains an insulating support 11. The upper and lower ends of the discharge electrode 7 are fixed to the upper partition 12 and lower partition 13 of the compartment 6 respectively via the insulating support 11. The upper end of the insulating support 11 is fixed to the lower surface of the upper partition 12, and the lower end of the insulating support 11 is fixed to the upper surface of the lower partition 13. The discharge electrode 7 is held between the two insulating supports 11. The insulating supports 11 are fixed to the partitions by bolts or snap-fit ​​connections. The insulating supports 11 are made of insulating material, serving both to fix the electrode and to ensure electrical insulation between the electrode and the reactor shell 1. The discharge electrodes 7 in each compartment 6 are arranged coaxially in the vertical direction, resulting in a compact overall structure and facilitating uniform flow of flue gas through each section of the electrode.

[0033] The discharge electrode 7 has a streamlined cross-section. In a preferred embodiment, the discharge electrode 7 has an airfoil or teardrop shape, with an arc-shaped windward side and a tapering leeward side. The arc-shaped windward side allows the flue gas to smoothly circulate along the electrode surface, while the tapering leeward side design allows the airflow to gradually converge behind the electrode, avoiding the formation of a vortex zone on the leeward side. This design fundamentally reduces the space for dust deposition on the back of the electrode.

[0034] Multiple guide grooves 8 are formed along the length of the surface of the discharge electrode 7, extending from the top to the bottom of the electrode and running parallel to the flue gas flow direction. The cross-section of the guide grooves 8 is V-shaped. The V-shaped guide grooves 8 do not have a flat bottom; even if dust falls into the groove, it will slide out along the V-shaped slope under the action of gravity and the scouring effect of the airflow. The function of the guide grooves 8 is to guide the flue gas to form a directional flow along the electrode surface, generating a continuous scouring effect on the electrode surface and carrying away the dust particles attached to the electrode surface. The opening width of the guide grooves 8 is preferably 0.1 mm to 0.5 mm, and the depth is preferably 0.05 mm to 0.2 mm.

[0035] The surface of the discharge electrode 7 is coated with an anti-dust-accumulation coating 9. The anti-dust-accumulation coating 9 is preferably a fluorocarbon resin coating, an organosilicon resin coating, or a ceramic coating. These coatings all have low surface energy and a low coefficient of friction, which can significantly reduce the adhesion of dust particles to the electrode surface, making it difficult for dust to form a firm bond. The thickness of the anti-dust-accumulation coating 9 is preferably from 10 micrometers to 100 micrometers.

[0036] The device also includes multiple independent high-voltage power supply modules 10, the number of which corresponds to the number of compartments 6. The discharge electrode 7 in each compartment 6 is connected to a single high-voltage power supply module 10, and each high-voltage power supply module 10 independently controls the on / off state and discharge intensity of its corresponding discharge electrode 7. This segmented independent control is the fourth core innovation of this invention.

[0037] The working process of the present invention will be described below.

[0038] The flue gas generated from waste incineration enters the reactor shell 1 through the flue gas inlet 2 at the bottom. The flue gas flows upwards through the flue gas channels 5 on each layer of horizontal partitions 4, passing through individual compartments 6. Within each compartment 6, the corresponding high-voltage power module 10 supplies power to the discharge electrode 7, generating low-temperature plasma. The high-energy active substances in the plasma oxidize the nitrogen oxides in the flue gas into water-soluble nitrogen dioxide or dinitrogen pentoxide. The treated flue gas is discharged from the flue gas outlet 3 at the top of the shell, entering subsequent treatment processes such as wet scrubbing.

[0039] During device operation, the discharge electrode 7 achieves dust prevention and self-cleaning through the following mechanism.

[0040] First, the streamlined cross-section of the electrode allows for smooth flow of flue gas. As the flue gas flows upwards over the electrode, the arc-shaped windward surface allows the airflow to smoothly circulate along the electrode surface, while the tapering design of the leeward surface causes the airflow to gradually converge behind the electrode. No significant vortex or recirculation zone is generated during the entire flow process, and dust flows along with the flue gas in the airflow, preventing deposition on the back of the electrode. Compared to the mechanism of dust deposition caused by vortex formation on the leeward surface of traditional circular electrodes, the streamlined electrode of this invention eliminates the root cause of dust accumulation from a hydrodynamic perspective.

[0041] Second, the guide channel 8 guides the flue gas to flow directionally along the electrode surface. As the flue gas flows along the electrode surface, the presence of the guide channel 8 alters the flow state of the boundary layer. The airflow velocity within the guide channel 8 is higher than the airflow velocity on the smooth electrode surface, creating a continuous scouring effect on the electrode surface. This scouring action can peel off and carry away loose dust particles already attached to the electrode surface. Simultaneously, the V-shaped cross-section of the guide channel 8 eliminates dead zones for dust accumulation; even if dust falls into the channel, it will slide out along the slope under the influence of gravity and the propulsion of the airflow. The scouring effect of the guide channel 8 works in conjunction with the dust reduction effect of the streamlined cross-section; the former actively removes already attached dust, while the latter reduces initial dust adhesion, both working together to maintain the cleanliness of the electrode surface.

[0042] Third, the anti-dust coating 9 reduces dust adhesion. Fluorocarbon resin coatings, silicone resin coatings, and ceramic coatings all have low surface energy, resulting in weak van der Waals forces between dust particles and the coating surface, making it difficult for them to adhere firmly. Dust particles adhering to the coating surface can easily detach under airflow or slight vibration. The anti-dust coating 9 works synergistically with the scouring effect of the guide channel 8: the guide channel 8 provides scouring force, and the coating reduces adhesion; together, they make it difficult for dust to remain on the electrode surface.

[0043] Fourth, segmented independent control enables maintenance without shutting down the system. Each electrode in each compartment 6 is powered by an independent power module. When an electrode in a compartment 6 requires maintenance or cleaning due to prolonged operation, the operator only needs to disconnect the corresponding high-voltage power module 10, and the electrode stops discharging. At this time, there is no high-voltage electric field in that compartment 6, and the operator can safely perform electrode inspection or cleaning operations. Electrodes in other compartments 6 continue to be powered by their respective high-voltage power modules 10 and continue normal operation. Once the maintenance of that electrode is completed and the power is reconnected, normal operation can resume. Throughout the entire process, the denitrification reactor does not need to be shut down, and flue gas treatment continues.

[0044] The streamlined cross-section reduces initial dust deposition from a hydrodynamic perspective, serving as the first line of defense against dust accumulation. The guide channel 8 actively removes deposited dust through airflow scouring, forming the second line of defense. The anti-dust coating 9 reduces dust adhesion strength, making removal easier, thus forming the third line of defense. Segmented independent control provides a non-stop operation path for electrode maintenance and cleaning, solving the pain point of maintenance requiring shutdown in existing technologies. These four elements work synergistically to achieve long-term self-cleaning of the electrodes and continuous operation of the device without shutdown.

[0045] The present invention will be further illustrated below through specific embodiments.

[0046] Example 1

[0047] In this embodiment, the reactor shell 1 is a vertical rectangular box, internally divided into four independent small compartments 6 by three layers of horizontal partitions 4. Each small compartment 6 contains a discharge electrode 7 with an airfoil-shaped cross-section, an arc-shaped front side and a tapering rear side. A guide groove 8 is formed along the length of the electrode surface, with a V-shaped cross-section. The electrode surface is coated with a fluorocarbon resin anti-dust coating 9. Each electrode is connected to an independent high-voltage power supply module 10.

[0048] Example 2

[0049] In this embodiment, the reactor shell 1 is a vertical rectangular box, internally divided into five independent small compartments 6 by four layers of horizontal partitions 4. Each small compartment 6 contains a discharge electrode 7 with a teardrop-shaped cross-section, an arc-shaped front side, and a tapering rear side. A guide groove 8 is formed along the length of the electrode surface, with a V-shaped cross-section. The electrode surface is coated with a ceramic anti-dust coating 9. Each electrode is connected to an independent high-voltage power supply module 10.

[0050] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A waste incineration flue gas denitrification reactor, comprising a reactor shell (1) and a discharge electrode (7) disposed within the shell, characterized in that: The reactor shell (1) has a vertical shell structure, with a flue gas inlet (2) at the bottom and a flue gas outlet (3) at the top. The shell is provided with several layers of horizontal partitions (4) at intervals along the height direction. The horizontal partitions (4) divide the interior of the shell into multiple independent small compartments (6) arranged in the vertical direction. The horizontal partitions (4) are provided with flue gas passages (5) for flue gas to pass through. Each of the compartments (6) is provided with an independent discharge electrode (7). The discharge electrode (7) is installed vertically in the compartment (6), and the discharge electrodes (7) in each compartment (6) are not connected to each other. The discharge electrode (7) has a streamlined cross-section; The surface of the discharge electrode (7) has multiple guide grooves (8) along its length. The surface of the discharge electrode (7) is coated with an anti-dust coating (9). The device also includes multiple independent high-voltage power modules (10), and the discharge electrode (7) in each of the small compartments (6) is connected to one of the high-voltage power modules (10). Each high-voltage power module (10) independently controls the on / off state and discharge intensity of the corresponding discharge electrode (7).

2. The waste incineration flue gas denitrification reaction device according to claim 1, characterized in that, The discharge electrode (7) has an airfoil-shaped cross section, with a circular arc on the windward side and a tapering shape on the leeward side.

3. The waste incineration flue gas denitrification reaction device according to claim 1, characterized in that, The guide groove (8) extends from the top end to the bottom end of the discharge electrode (7) along the length direction of the discharge electrode (7), and the direction of the guide groove (8) is parallel to the flue gas flow direction.

4. The waste incineration flue gas denitrification reaction device according to claim 1, characterized in that, The cross-section of the guide channel (8) is V-shaped.

5. The waste incineration flue gas denitrification reaction device according to claim 1, characterized in that, The anti-dust coating (9) is a fluorocarbon resin coating, an organosilicon resin coating, or a ceramic coating.

6. The waste incineration flue gas denitrification reaction device according to claim 1, characterized in that, Each of the small compartments (6) is also provided with an insulating support (11), and the upper and lower ends of the discharge electrode (7) are fixed to the upper partition (12) and lower partition (13) of the small compartment (6) respectively by the insulating support (11).

7. The waste incineration flue gas denitrification reaction device according to claim 1, characterized in that, The discharge electrodes (7) in each small compartment (6) are arranged coaxially in the vertical direction.

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