Flue gas denitration system

Abstract

The utility model belongs to the technical field of industrial flue gas purification, and relates to a flue gas denitration system which comprises a flue gas denitration reactor, a flue gas conveying pipeline, an ammonia gas conveying pipeline and a compressed air conveying pipeline, the flue gas denitration reactor is filled with a catalyst; the gas outlet end of the flue gas conveying pipeline is communicated with the flue gas denitration reactor; the gas outlet end of the ammonia gas conveying pipeline is communicated with the flue gas denitration reactor; the compressed air conveying pipeline is communicated with the ammonia conveying pipeline through a mixer, and a plurality of guide plates are arranged along the axial direction of the mixer. According to the flue gas denitration reactor, the mixer is arranged between the ammonia gas conveying pipeline and the compressed air conveying pipeline, the flow guide plate is arranged in the mixer, and ammonia gas and compressed air are fully mixed under the action of the flow guide plate, so that the ammonia gas entering the flue gas denitration reactor is uniformly distributed, and nitrogen oxides in flue gas are fully contacted with the ammonia gas; and nitrogen and water vapor are generated, so that the flue gas is purified, and the denitration efficiency of the denitration system is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of industrial flue gas purification, specifically relates to a flue gas denitration system. BACKGROUND

[0002] The flue gas denitration system is designed for processing nitrogen oxides emitted in industrial production such as coal-fired power plants, steel, and chemical industry, and its function is to reduce nitrogen oxides to a safe range. The flue gas denitration system mainly has two processes of selective catalytic reduction and selective non-catalytic reduction. Among them, the selective catalytic reduction process is to add ammonia gas into the flue gas, and under the action of the catalyst, the ammonia gas and the nitrogen oxides in the flue gas will have a reduction reaction at a proper temperature to generate nitrogen and water vapor, thereby realizing the purification treatment of the flue gas.

[0003] There is certain research on the flue gas denitration system in the prior art. Referring to the patent document with the application number 201920090179.2, an ammonia gas supply system for flue gas denitration is disclosed, which includes: an ammonia water gasifier, an ammonia water atomization system, and an ammonia water gasification system; the ammonia water atomization system includes a spray gun installed in the ammonia water gasifier, the spray gun liquid inlet is communicated with the ammonia water pipeline, and the spray gun atomizing air inlet is communicated with the air compressor through the atomizing air pipeline; the ammonia water gasification system includes a heat exchanger and a fan, and the heat exchanger is installed in the boiler flue; the atomizing air pipeline is communicated with a compressed air storage tank, which realizes the buffer storage of compressed air, and ensures that the atomizing air pressure of the spray gun is stable and constant.

[0004] Therefore, by adding a compressed air storage tank on the atomizing air pipeline, the buffer storage of compressed air is realized, and the atomizing effect of ammonia water is optimized. However, in actual operation, the ammonia gas and compressed air are not uniformly mixed, which leads to uneven distribution of ammonia gas in the flue gas, and part of the nitrogen oxides cannot be fully reduced due to insufficient contact with ammonia gas, which affects the effective mixing of ammonia gas and nitrogen oxides in the flue gas, and finally reduces the denitration efficiency of the denitration system. UTILITY MODEL CONTENTS

[0005] In order to solve the technical problem of uneven mixing of ammonia gas and compressed air in the background art, which leads to uneven distribution of ammonia gas in the flue gas and reduces the denitration efficiency of the denitration system, the utility model provides a flue gas denitration system.

[0006] The utility model discloses a flue gas denitration system, set up the mixer between ammonia gas delivery pipeline and compressed air delivery pipeline, and set up the deflector inside the mixer, under the action of deflector, ammonia gas and compressed air fully mix, make the ammonia gas that enters flue gas denitration reactor distribution uniform, and the nitrogen oxides in flue gas fully contact with ammonia gas, thereby under the action of catalyst, efficient reduction reaction takes place, nitrogen and water vapor are generated, realize the purification treatment of flue gas, improve the denitration efficiency of denitration system.

[0007] To solve the above technical problems, the utility model provides the following technical scheme:

[0008] A flue gas denitration system, comprising: a flue gas denitration reactor, a flue gas delivery pipeline, an ammonia gas delivery pipeline, and a compressed air delivery pipeline; the flue gas denitration reactor is filled with a catalyst, and the flue gas denitration reactor is in communication with a boiler; the outlet end of the ammonia gas delivery pipeline is in communication with the flue gas denitration reactor, the ammonia gas delivery pipeline is used for delivering ammonia gas into the flue gas denitration reactor, and the ammonia gas performs denitration treatment on flue gas under the action of the catalyst; the compressed air delivery pipeline is in communication with the ammonia gas delivery pipeline through a mixer, the compressed air delivery pipeline is used for delivering compressed air into the ammonia gas delivery pipeline, the axial direction of the mixer is the same as the flow direction of the ammonia gas, and a plurality of deflectors are arranged along the axial direction of the mixer; one end of the deflector is connected to the inner wall of the flue gas denitration reactor, and the other end of the deflector extends to the outlet end of the mixer.

[0009] In one specific implementation, the angle between the plane of the deflector and the axial direction of the mixer ranges from 30° to 60°.

[0010] In one specific implementation, the outlet end of the ammonia gas delivery pipeline is provided with a plurality of groups of jet short pipes; the plurality of groups of jet short pipes are arranged in parallel along the axial direction of the flue gas delivery pipeline, and the outlet end of the jet short pipe extends into the inner cavity of the flue gas delivery pipeline.

[0011] In one specific implementation, the outlet end of each jet short pipe is provided with a plurality of nozzles uniformly distributed along the radial direction of the flue gas delivery pipeline.

[0012] In one specific implementation, a throttle valve and a flow meter are installed on each jet short pipe.

[0013] In one specific implementation, a plurality of catalyst supports are arranged along the axial direction of the flue gas denitration reactor, and the plurality of catalyst supports divide the inner cavity of the flue gas denitration reactor into a plurality of catalyst filling units; each catalyst support is arranged along the radial direction of the flue gas denitration reactor.

[0014] In one specific embodiment, the catalyst filling unit far away from the gas inlet end of the flue gas denitration reactor is a catalyst pre-installation layer, and the catalyst filling units close to the gas inlet end of the flue gas denitration reactor are all catalyst initial installation layers.

[0015] In one specific embodiment, a soot blower is installed in each of the catalyst initial installation layers.

[0016] In one specific embodiment, a catalyst hoisting track and a catalyst installation door are installed on the side wall of the flue gas denitration reactor, and the catalyst hoisting track is communicated with the inner cavity of the flue gas denitration reactor through the catalyst installation door.

[0017] In one specific embodiment, the flue gas denitration reactor is communicated with the boiler through a flue gas conveying pipeline; the gas inlet end of the flue gas conveying pipeline is communicated with the boiler, and the gas outlet end of the flue gas conveying pipeline is communicated with the flue gas denitration reactor.

[0018] In summary, the flue gas denitration system has the following beneficial technical effects:

[0019] 1. The flue gas denitration system sets a mixer between the ammonia conveying pipeline and the compressed air conveying pipeline, and sets a flow guide plate inside the mixer; under the action of the flow guide plate, the ammonia and the compressed air are fully mixed, so that the ammonia entering the flue gas denitration reactor is uniformly distributed, the nitrogen oxides in the flue gas fully contact with the ammonia, and then the reduction reaction occurs under the action of the catalyst to generate nitrogen and water vapor, thereby realizing the purification treatment of the flue gas and improving the denitration efficiency of the denitration system.

[0020] 2. The flue gas denitration system adopts multiple groups of jet short pipes which are distributed in parallel along the axial direction of the flue gas conveying pipeline, and multiple nozzles which are uniformly distributed along the radial direction of the flue gas conveying pipeline are arranged at the outlet end of each jet short pipe, so as to further enhance the dispersion uniformity of the ammonia in the flue gas, improve the mixing efficiency of the ammonia and the flue gas, and reduce the escape amount of the ammonia, thereby reducing the potential influence of the denitration system on the environment. Preferably, a throttle valve and a flow meter are installed on each jet short pipe to realize the accurate control of the ammonia flow, facilitate the flexible adjustment of the ammonia supply amount according to the actual working condition, and ensure the stable performance of the denitration reaction.

[0021] 3. The flue gas denitration system sets multiple catalyst supports in the flue gas denitration reactor to divide the inner cavity of the reactor into multiple catalyst filling units, so as to facilitate the replacement and maintenance of the catalyst, and the catalyst pre-installation layer is arranged to facilitate the flexible adjustment of the catalyst filling amount according to the denitration requirements in different stages. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is the overall structure schematic diagram of the flue gas denitration system.

[0023] Figure 2 is Figure 1 A part of enlarged view in the figure.

[0024] Figure 3 is a structural schematic view of the mixer in the flue gas denitration system of the utility model.

[0025] Figure 4 is a sectional view of the mixer in the flue gas denitration system of the utility model.

[0026] Figure 5 is a schematic view of the internal structure of the mixer in the flue gas denitration system of the utility model.

[0027] Mark explanation: 1, flue gas denitration reactor, 2, flue gas conveying pipeline, 3, ammonia gas conveying pipeline, 4, compressed air conveying pipeline, 5, mixer, 6, deflector, 7, catalyst support, 8, catalyst pre-reserved layer, 9, catalyst initial installation layer, 10, injection short pipe, 11, spray head, 12, throttle valve, 13, flowmeter, 14, ammonia gas inlet, 15, compressed air inlet. Specific implementation

[0028] The technical scheme of the utility model will be further explained and described below in combination with the drawings and embodiments, but the utility model is not limited to the implementation mode described below.

[0029] With reference to Figures 1-3 , in the utility model, the mixer 5 is arranged between the ammonia gas conveying pipeline 3 and the compressed air conveying pipeline 4, and the deflector 6 is arranged inside the mixer 5, under the action of the deflector 6, the ammonia gas and the compressed air are fully mixed, so that the ammonia gas entering the flue gas denitration reactor 1 is uniformly distributed, the nitrogen oxides in the flue gas fully contact with the ammonia gas, so that the reduction reaction is efficiently generated under the action of the catalyst, nitrogen and water vapor are generated, the purification treatment of the flue gas is realized, and the denitration efficiency of the denitration system is improved.

[0030] With reference to Figure 1 and Figure 2 , a flue gas denitration system, comprising: a flue gas denitration reactor 1, an ammonia gas conveying pipeline 3 and a compressed air conveying pipeline 4, the flue gas denitration reactor 1 is filled with catalyst, and the flue gas denitration reactor 1 is communicated with a boiler, the gas outlet end of the ammonia gas conveying pipeline 3 is communicated with the flue gas denitration reactor 1, the ammonia gas conveying pipeline 3 is used for conveying ammonia gas into the flue gas denitration reactor 1, and the ammonia gas is used for carrying out denitration treatment on the flue gas under the action of the catalyst, the compressed air conveying pipeline 4 is communicated with the ammonia gas conveying pipeline 3 through the mixer 5, the axial direction of the mixer 5 is same with the flow direction of the ammonia gas, and the compressed air conveying pipeline 4 is used for conveying compressed air into the ammonia gas conveying pipeline 3.

[0031] Specifically, the flue gas denitration reactor 1 is communicated with the boiler through the flue gas conveying pipeline 2; the gas inlet end of the flue gas conveying pipeline 2 is communicated with the boiler, and the gas outlet end of the flue gas conveying pipeline 2 is communicated with the flue gas denitration reactor 1.

[0032] More specifically, the mixer 5 is provided with the ammonia gas inlet 14 and the compressed air inlet 15 at the end far away from the flue gas denitration reactor 1, so that the ammonia gas in the ammonia gas conveying pipeline 3 enters the mixer 5 through the ammonia gas inlet 14, and the compressed air in the compressed air conveying pipeline 4 enters the mixer 5 through the compressed air inlet 15.

[0033] In this embodiment, the flue gas generated from the boiler is conveyed into the flue gas denitration reactor 1 through the flue gas conveying pipeline 2; inside the flue gas denitration reactor 1, the catalyst filling unit loaded with catalysts processes the passing flue gas; the catalysts promote the reduction reaction between the ammonia gas and the nitrogen oxides in the flue gas to generate harmless nitrogen and water vapor.

[0034] Referring to Figures 3-5 , in order to ensure that the ammonia gas and the compressed air are fully mixed, a plurality of guide plates 6 are arranged along the axial direction of the mixer 5; one end of the guide plate 6 is connected with the inner wall of the flue gas denitration reactor 1, and the other end of the guide plate 6 extends to the gas outlet end of the mixer 5.

[0035] Specifically, the included angle between the plane where the guide plate 6 is located and the axial direction of the mixer 5 ranges from 30° to 60°. In this embodiment, the included angle between the plane where the guide plate 6 is located and the axial direction of the mixer 5 can be 30°, 45°, 60°, etc., and a suitable included angle range is set to ensure that the ammonia gas and the compressed air are fully mixed; preferably, the included angle between the plane where the guide plate 6 is located and the axial direction of the mixer 5 is 30°.

[0036] Referring to Figure 1 , a plurality of catalyst supports 7 are distributed along the axial direction of the flue gas denitration reactor 1, and the plurality of catalyst supports 7 divide the inner cavity of the flue gas denitration reactor 1 into a plurality of catalyst filling units; each catalyst support 7 is arranged along the radial direction of the flue gas denitration reactor 1. In this embodiment, the number of catalyst supports 7 is not specifically limited, and the operator can set it according to the actual process requirements.

[0037] Further, one catalyst filling unit far away from the gas inlet end of the flue gas denitration reactor 1 is a catalyst reserved layer 8, and the plurality of catalyst filling units close to the gas inlet end of the flue gas denitration reactor 1 are all catalyst initial loading layers 9.

[0038] Further, each of the catalyst initial loading layer 9 is provided with a soot blower; by installing a soot blower in each of the catalyst initial loading layer 9, the activity reduction caused by the catalyst surface soot is prevented, the service life of the catalyst is prolonged, and the continuous and efficient operation of the denitration system is ensured.

[0039] Further, the side wall of the flue gas denitration reactor 1 is provided with a catalyst hoisting track and a catalyst installation door, and the catalyst hoisting track communicates with the inner cavity of the flue gas denitration reactor 1 through the catalyst installation door; the catalyst hoisting track and the catalyst installation door are arranged to facilitate the hoisting and installation of the catalyst by the operator, and further improve the denitration efficiency of the denitration system.

[0040] Embodiment 2:

[0041] Referring to Figure 1 and Figure 2 , the flue gas denitration system of the embodiment, on the basis of embodiment 1, the outlet end of the ammonia gas conveying pipeline 3 is provided with a plurality of groups of injection short pipes 10; a plurality of groups of the injection short pipes 10 are distributed in parallel along the axial direction of the flue gas conveying pipeline 2, and the gas outlet end of the injection short pipe 10 extends into the inner cavity of the flue gas conveying pipeline 2.

[0042] Further, the outlet end of each of the injection short pipes 10 is provided with a plurality of spray heads 11 which are uniformly distributed in the radial direction of the flue gas conveying pipeline 2, so that the ammonia gas is uniformly sprayed in the form of fine droplets into the flue gas, further improving the mixing efficiency of the ammonia gas and the flue gas.

[0043] Further, each of the injection short pipes 10 is provided with a throttle valve 12 and a flow meter 13; the throttle valve 12 is used to adjust the flow of ammonia gas, so as to ensure that the supply amount of ammonia gas can be flexibly adjusted according to the actual working condition; the flow meter 13 is used to monitor the flow of ammonia gas in real time, so as to provide accurate flow data for the operator to make accurate adjustment.

[0044] The working principle of the flue gas denitration system is as follows: after the flue gas is generated from the boiler, the flue gas is conveyed to the flue gas denitration reactor 1 through the flue gas conveying pipeline 2; the ammonia gas is conveyed to the mixer 5 through the ammonia gas conveying pipeline 3, and in the mixer 5, the compressed air of the compressed air conveying pipeline 4 meets and mixes with the ammonia gas, and the ammonia gas mixed with the compressed air is conveyed to the flue gas denitration reactor 1; in the flue gas denitration reactor 1, the catalyst is arranged in the plurality of catalyst filling units, and the catalyst catalyzes the selective catalytic reduction reaction of the ammonia gas and the nitrogen oxides in the flue gas, so as to convert the nitrogen oxides in the flue gas into nitrogen and water vapor, and realize the purification treatment of the flue gas.

[0045] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application, so that: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A flue gas denitration system characterized by, The application relates to a flue gas denitration reactor (1) which is filled with a catalyst and is in communication with a boiler. An ammonia gas conveying pipeline (3) is in communication with the flue gas denitration reactor (1) at an outlet end, and is used for conveying ammonia gas into the flue gas denitration reactor (1) for denitration treatment of flue gas under the action of the catalyst; and a compressed air conveying pipeline (4) is in communication with the ammonia gas conveying pipeline (3) through a mixer (5), and is used for conveying compressed air into the ammonia gas conveying pipeline (3); the mixer (5) has the same axial direction as the flow direction of the ammonia gas, and a plurality of guide plates (6) are arranged along the axial direction of the mixer (5), one end of the guide plate (6) is connected with the inner wall of the flue gas denitration reactor (1), and the other end of the guide plate (6) extends to the outlet end of the mixer (5). The included angle between the plane of the guide plate (6) and the axial direction of the mixer (5) ranges from 30 DEG to 60 DEG. The outlet end of the ammonia gas conveying pipeline (3) is provided with a plurality of groups of jet short pipes (10).

2. The flue gas denitration system according to claim 1, characterized by: The plurality of groups of jet short pipes (10) are arranged in parallel along the axial direction of the flue gas conveying pipeline (2), and the outlet end of the jet short pipe (10) extends into the inner cavity of the flue gas conveying pipeline (2).

3. The flue gas denitration system according to claim 1 or 2, characterized by: The outlet end of each jet short pipe (10) is provided with a plurality of nozzles (11) which are uniformly distributed along the radial direction of the flue gas conveying pipeline (2). A throttle valve (12) and a flowmeter (13) are arranged on each jet short pipe (10).

4. The flue gas denitration system according to claim 3, characterized by: A plurality of catalyst supports (7) are arranged along the axial direction of the flue gas denitration reactor (1), and the inner cavity of the flue gas denitration reactor (1) is divided into a plurality of catalyst filling units by the catalyst supports (7).

5. The flue gas denitration system according to claim 4, characterized by: Each catalyst support (7) is arranged along the radial direction of the flue gas denitration reactor (1).

6. The flue gas denitration system according to claim 1, characterized by: A catalyst pre-reserved layer (8) is arranged in a catalyst filling unit which is far away from the inlet end of the flue gas denitration reactor (1), and a plurality of catalyst initial filling layers (9) are arranged in catalyst filling units which are close to the inlet end of the flue gas denitration reactor (1). A soot blower is arranged in each catalyst initial filling layer (9).

7. The flue gas denitration system according to claim 6, characterized by: A catalyst hoisting track and a catalyst installation door are arranged on the side wall of the flue gas denitration reactor (1), and the catalyst hoisting track is in communication with the inner cavity of the flue gas denitration reactor (1) through the catalyst installation door.

8. The flue gas denitration system according to claim 7, characterized by: The flue gas denitration reactor (1) is in communication with the boiler through a flue gas conveying pipeline (2).

9. The flue gas denitration system according to claim 8, characterized by: The inlet end of the flue gas conveying pipeline (2) is in communication with the boiler, and the outlet end of the flue gas conveying pipeline (2) is in communication with the flue gas denitration reactor (1).

10. The flue gas denitration system according to claim 1, characterized by: ​ ​

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