Nitrogen oxide-containing waste gas treatment equipment

Abstract

The utility model discloses nitrogen oxide-containing waste gas treatment equipment which comprises a first air preheater, the first air preheater is connected with a first external heat source through a pipeline, and the first external heat source is connected with a bag-type dust collector through a pipeline. Waste gas is heated through a first air preheater and then enters a bag-type dust collector and an electric dust collector for dust removal, the waste gas subjected to dust removal through the bag-type dust collector enters a gas / gas heat exchanger, then the waste gas enters an SCR reactor and then enters a sulfur dioxide reactor after being heated by a second external heat source, and the sulfur dioxide reactor is heated by a second external heat source. The waste gas returns to the gas / gas heat exchanger again and enters the condensing tower, hot air in the condensing tower is recycled through the heat recycling system, sulfuric acid enters the sulfuric acid collecting box, denitrification treatment is achieved, heat of the waste gas is recycled, dust interception is achieved, the waste gas is fully treated, and the system is simple in structure.

Description

Technical Field

[0001] This utility model relates to the field of nitrogen oxide waste gas treatment technology, specifically to a nitrogen oxide-containing waste gas treatment device. Background Technology

[0002] Nitrogen oxides refer to compounds composed solely of nitrogen and oxygen, including various compounds such as nitrous oxide (N₂O), nitric oxide (NO), nitrogen dioxide (NO₂), nitrous oxide (N₂O₃), nitrous oxide (N₂O₄), and nitrous oxide (N₂O₅). Except for nitrous oxide and nitrogen dioxide, other nitrogen oxides are unstable and transform into nitrogen dioxide and nitric oxide upon exposure to light, moisture, or heat; nitric oxide further transforms into nitrogen dioxide. Therefore, occupational exposure to a mixture of several gases, often referred to as fumes, primarily consists of nitric oxide and nitrogen dioxide, with nitrogen dioxide being the dominant component. All nitrogen oxides possess varying degrees of toxicity. Boiler flue gas contains sulfur dioxide, carbon monoxide, hydrocarbons, and nitrogen oxides, all of which are harmful gases.

[0003] Existing boiler exhaust gas treatment methods include chemical spray towers, bio-trickling filtration, UV ultraviolet light, activated carbon adsorption, condensation, and VOCs adsorption. However, using any single method alone cannot achieve sufficient treatment of nitrogen oxides, and the treated exhaust gas still causes significant air pollution when released into the atmosphere. Furthermore, using two or more of these methods results in a complex exhaust gas treatment structure. Therefore, it is necessary to develop a treatment device for nitrogen oxide-containing exhaust gas that can achieve sufficient treatment while maintaining a relatively simple treatment structure. Utility Model Content

[0004] In view of the problems existing in the current nitrogen oxide-containing waste gas treatment equipment, this utility model is proposed.

[0005] Therefore, the purpose of this utility model is to provide a nitrogen oxide-containing waste gas treatment device, which solves the problem that existing boiler waste gas treatment methods, including chemical spray towers, biological trickling filtration, UV ultraviolet light, activated carbon adsorption, condensation, and VOCs adsorption, cannot achieve sufficient treatment of nitrogen oxides when using any one of these methods alone. The treated waste gas still causes serious air pollution when released into the atmosphere. Furthermore, using two or more of the above methods for waste gas treatment leads to a complex waste gas treatment structure. Therefore, it is necessary to develop a treatment device for nitrogen oxide-containing waste gas that can achieve sufficient treatment of nitrogen oxide-containing waste gas while maintaining a relatively simple treatment structure.

[0006] To solve the above-mentioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:

[0007] A nitrogen oxide-containing waste gas treatment device includes a first air preheater, which is connected to a first external heat source via a pipeline. The first external heat source is connected to a bag filter via a pipeline. The bag filter is connected to a first blower via a pipeline. The first blower is connected to a gas / gas heat exchanger via a pipeline. The gas / gas heat exchanger is connected to an SCR reactor via a pipeline. The SCR reactor is connected to a second external heat source via a pipeline. The second external heat source is connected to a sulfur dioxide reactor via a pipeline. The outlet of the sulfur dioxide reactor is connected to the gas / gas heat exchanger via a pipeline. The outlet of the gas / gas heat exchanger is connected to a condenser tower via a pipeline. The hot air outlet of the condenser tower is connected to a hot air heat recovery system via a pipeline. The flue gas outlet of the condenser tower is connected to a third external heat source via a pipeline.

[0008] In a preferred embodiment of the nitrogen oxide-containing waste gas treatment equipment described in this utility model, the third external heating source is connected to a chimney via a pipe.

[0009] As a preferred embodiment of the nitrogen oxide-containing waste gas treatment equipment of this utility model, it further includes a cooler, wherein the cooler is connected to a second blower via a pipeline, and the second blower is connected to a condensation tower via a pipeline.

[0010] In a preferred embodiment of the nitrogen oxide-containing waste gas treatment equipment described in this utility model, the sulfuric acid outlet of the condensation tower is connected to a sulfuric acid collector, and the sulfuric acid collector is connected to a sulfuric acid storage tank via a pipeline.

[0011] In a preferred embodiment of the nitrogen oxide-containing waste gas treatment equipment described in this utility model, the air inlet of the first air preheater is connected to the air outlet of the boiler via a conduit.

[0012] As a preferred embodiment of the nitrogen oxide-containing waste gas treatment equipment of this utility model, it further includes an electrostatic precipitator connected to a first air preheater via a conduit, wherein the electrostatic precipitator is connected to a chimney via a pipe.

[0013] As a preferred embodiment of the nitrogen oxide-containing waste gas treatment equipment described in this utility model, it further includes a secondary flue gas treatment system;

[0014] The secondary flue gas treatment system includes a storage tank connected to an electrostatic precipitator via a conduit. An economizer is installed inside the storage tank. The storage tank is connected to a spray tower via a pipeline. An ammonia spray grid and a static mixer are installed inside the spray tower.

[0015] As a preferred embodiment of the nitrogen oxide-containing waste gas treatment equipment of this utility model, the spray tower is equipped with guide vanes and a rectifier grid. The storage tank and the spray tower are both connected to a second air preheater through pipes. The second air preheater is connected to a dust collector through a conduit. The dust collector is connected to a wet flue gas desulfurization system through a pipe.

[0016] In a preferred embodiment of the nitrogen oxide-containing waste gas treatment equipment described in this utility model, the storage tank is connected to an evaporator via a pipeline, and the evaporator is connected to an ammonia storage tank via a pipeline.

[0017] An economizer bypass is provided between the storage tank and the spray tower, and the exhaust port of the wet flue gas desulfurization system is connected to the chimney through a pipeline.

[0018] Compared with existing technologies:

[0019] The exhaust gas is heated by a first air preheater, then enters a bag filter and an electrostatic precipitator for dust removal. After dust removal by the bag filter, the exhaust gas enters a gas / gas heat exchanger, then enters an SCR reactor. After being heated by a second external heat source, it enters a sulfur dioxide reactor. The exhaust gas then returns to the gas / gas heat exchanger and enters a condenser tower. The hot air in the condenser tower is recovered through a heat recovery system, and the sulfuric acid enters a sulfuric acid collector. This process not only achieves denitrification but also heat recovery from the exhaust gas and dust interception, resulting in thorough exhaust gas treatment and a simple system structure. Attached Figure Description

[0020] Figure 1 The system flowchart provided for Embodiment 1 of this utility model;

[0021] Figure 2 This is a system flowchart provided for Embodiment 2 of the present invention;

[0022] Figure 3 A flowchart of the secondary flue gas treatment system provided in Embodiment 2 of this utility model.

[0023] Figure reference numerals: Boiler 1, First air preheater 2, Cooler 3, Condensing tower 4, Electrostatic precipitator 5, Chimney 6, First external heat source 7, Bag filter 8, Gas / gas heat exchanger 9, SCR reactor 10, Second external heat source 11, Sulfur dioxide reactor 12, Sulfuric acid storage tank 13, Third external heat source 14, First blower 15, Sulfuric acid header 16, Hot air heat recovery system 17, Second blower 18, Second air preheater 19, Dust collector 20, Wet flue gas desulfurization system 21, Spray tower 23, Static mixer 24, Guide vane 25, Economizer bypass 26, Storage tank 27, Evaporator 28, Ammonia storage tank 29, Economizer 30. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0025] Example 1:

[0026] This utility model provides a device for treating nitrogen oxide-containing waste gas. Please refer to [link / reference]. Figure 1 The system includes a first air preheater 2, which is connected to a first external heat source 7 via a pipe. The first external heat source 7 is connected to a bag filter 8 via a pipe. The bag filter 8 is connected to a first blower 15 via a pipe. The first blower 15 is connected to a gas / gas heat exchanger 9 via a pipe. The gas / gas heat exchanger 9 is connected to an SCR reactor 10 via a pipe. The SCR reactor 10 is connected to a second external heat source 11 via a pipe. The second external heat source 11 is connected to a sulfur dioxide reactor 12 via a pipe. The outlet of the sulfur dioxide reactor 12 is connected to the gas / gas heat exchanger 9 via a pipe. The outlet of the gas / gas heat exchanger 9 is connected to a condenser tower 4 via a pipe. The hot air outlet of the condenser tower 4 is connected to a hot air heat recovery system 17 via a pipe. The flue gas outlet of the condenser tower 4 is connected to a third external heat source 14 via a pipe.

[0027] The third external heating source 14 is connected to the chimney 6 via a pipe, and also includes an electrostatic precipitator 8 connected to the first air preheater 2 via a conduit. The electrostatic precipitator 8 is connected to the chimney 6 via a pipe.

[0028] It also includes a cooler 3, which is connected to a second blower 18 via a pipeline. The second blower 18 is connected to a condenser tower 4 via a pipeline. The sulfuric acid outlet of the condenser tower 4 is connected to a sulfuric acid collector 16, which is connected to a sulfuric acid storage tank 13 via a pipeline. The air inlet of the first air preheater 2 is connected to the air outlet of the boiler 1 via a conduit. It also includes an electrostatic precipitator 5 connected to the first air preheater 2 via a conduit, and the electrostatic precipitator 5 is connected to a chimney 6 via a pipeline.

[0029] In practical use, the exhaust gas from boiler 1 is first heated in the first air preheater 2, and then enters the bag filter 8 and electrostatic precipitator 5 for dust removal. The exhaust gas after dust removal by the bag filter 8 enters the gas / gas heat exchanger 9, and then enters the SCR reactor 10. After being heated by the second external heat source 11, it enters the sulfur dioxide reactor 12. Then the exhaust gas returns to the gas / gas heat exchanger 9, and then enters the condenser tower 4. The pure flue gas is then discharged through the chimney 6, while the hot air in the condenser tower 4 is recovered through the heat recovery system 17, and the sulfuric acid enters the sulfuric acid collector 16.

[0030] Example 2:

[0031] See attached document Figure 2-3 Unlike Example 1, it also includes a secondary flue gas treatment system;

[0032] The secondary flue gas treatment system includes a storage tank 27 connected to the electrostatic precipitator 5 via a conduit. An economizer 30 is installed inside the storage tank 27. The storage tank 27 is connected to a spray tower 23 via a pipeline. An ammonia spraying grid and a static mixer 24 are installed inside the spray tower 23.

[0033] The spray tower 23 is equipped with guide vanes 25 and a flow rectifier grid. The storage tank 27 and the spray tower 23 are both connected to the second air preheater 19 through pipes. The second air preheater 19 is connected to the dust collector 20 through a conduit. The dust collector 20 is connected to the wet flue gas desulfurization system 21 through a pipe.

[0034] The storage tank 27 is connected to the evaporator 28 via a pipeline, and the evaporator 28 is connected to the ammonia storage tank 29 via a pipeline; an economizer bypass 26 is provided between the storage tank 27 and the spray tower 23, and the exhaust port of the wet flue gas desulfurization system 26 is connected to the chimney 6 via a pipeline.

[0035] In practical use, the exhaust gas from boiler 1 is first heated in the first air preheater 2, and then enters the bag filter 8 and electrostatic precipitator 5 for dust removal. The exhaust gas after dust removal by the bag filter 8 enters the gas / gas heat exchanger 9, and then enters the SCR reactor 10. After being heated by the second external heating source 11, it enters the sulfur dioxide reactor 12. Then the exhaust gas returns to the gas / gas heat exchanger 9, and then enters the condenser tower 4. The hot air in the condenser tower 4 is recovered through the heat recovery system 17, and the sulfuric acid enters the sulfuric acid collector 16.

[0036] The pure flue gas enters the storage tank 27, then enters the spray tower 23 for ammonia injection treatment, then enters the second air preheater 19, then enters the dust collector 20 for dust removal again, and then enters the wet desulfurization system 21 for desulfurization treatment, so as to achieve full treatment of the boiler 1 exhaust gas.

[0037] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the features in the embodiments disclosed in this invention can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A nitrogen oxide-containing waste gas treatment device, comprising a first air preheater (2), characterized in that: The first air preheater (2) is connected to a first external heating source (7) via a pipe. The first external heating source (7) is connected to a bag filter (8) via a pipe. The bag filter (8) is connected to a first blower (15) via a pipe. The first blower (15) is connected to a gas / gas heat exchanger (9) via a pipe. The gas / gas heat exchanger (9) is connected to an SCR reactor (10) via a pipe. The SCR reactor (10) is connected to a second external heating source (11) via a pipe. The second external heating source (11) is connected to a sulfur dioxide reactor (12) via a pipe. The outlet of the sulfur dioxide reactor (12) is connected to the gas / gas heat exchanger (9) via a pipe. The outlet of the gas / gas heat exchanger (9) is connected to a condenser tower (4) via a pipe. The hot air outlet of the condenser tower (4) is connected to a hot air heat recovery system (17) via a pipe. The flue gas outlet of the condenser tower (4) is connected to a third external heating source (14) via a pipe.

2. The nitrogen oxide-containing waste gas treatment equipment according to claim 1, characterized in that, The third external heating source (14) is connected to a chimney (6) via a pipe.

3. The nitrogen oxide-containing waste gas treatment equipment according to claim 1, characterized in that, It also includes a cooler (3), which is connected to a second blower (18) via a pipe, and the second blower (18) is connected to a condenser tower (4) via a pipe.

4. The nitrogen oxide-containing waste gas treatment equipment according to claim 1, characterized in that, The sulfuric acid outlet of the condenser (4) is connected to a sulfuric acid collector (16), which is connected to a sulfuric acid storage tank (13) via a pipeline.

5. The nitrogen oxide-containing waste gas treatment equipment according to claim 1, characterized in that, The air inlet of the first air preheater (2) is connected to the air outlet of the boiler (1) via a conduit.

6. The nitrogen oxide-containing waste gas treatment equipment according to claim 1, characterized in that, It also includes an electrostatic precipitator (5) connected to the first air preheater (2) via a conduit, the electrostatic precipitator (5) being connected to the chimney (6) via a pipe.

7. The nitrogen oxide-containing waste gas treatment equipment according to claim 1, characterized in that, It also includes a secondary flue gas treatment system; The secondary flue gas treatment system includes a storage tank (27) connected to an electrostatic precipitator (5) via a conduit. An economizer (30) is installed inside the storage tank (27). A spray tower (23) is connected to the storage tank (27) via a pipe. An ammonia spraying grid and a static mixer (24) are installed inside the spray tower (23).

8. The nitrogen oxide-containing waste gas treatment equipment according to claim 7, characterized in that, The spray tower (23) is equipped with guide vanes (25) and a flow grid. The storage tank (27) and the spray tower (23) are both connected to the second air preheater (19) through pipes. The second air preheater (19) is connected to the dust collector (20) through a conduit. The dust collector (20) is connected to the wet flue gas desulfurization system (21) through a pipe.

9. The nitrogen oxide-containing waste gas treatment equipment according to claim 8, characterized in that, The storage tank (27) is connected to an evaporator (28) via a pipe, and the evaporator (28) is connected to an ammonia storage tank (29) via a pipe. An economizer bypass (26) is provided between the storage tank (27) and the spray tower (23), and the exhaust port of the wet flue gas desulfurization system (21) is connected to the chimney (6) through a pipeline.

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