A combined scr and sncr circulating fluidized bed boiler

Abstract

The utility model discloses a circulating fluidized bed boiler of SCR and SNCR jointed decontamination, including hearth and ammonia water supply box, the outlet of hearth is connected with cyclone separator through bolt locking, the top end interface of cyclone separator is connected with superheated coal saving subassembly through pipeline, the inner wall of hearth is provided with the ammonia supplementing spray gun subassembly for ammonia water spray, one side of ammonia water supply box is installed with the water outlet through inlaying, the utility model discloses the processing cylinder, filter plate, mounting bracket, rotating column and cleaning component through the design, install the processing cylinder with filter structure in the pipeline system of ammonia water supply, when ammonia water flows in the processing cylinder, the ammonia water with impurity passes through filter plate, and filter plate intercepts and filters the impurity in ammonia water, avoids the impurity to be transported to the ammonia supplementing spray gun subassembly and causes the blockage of spray gun spray head to make ammonia water unable to spray out enough and influences decontamination effect.

Description

Technical Field

[0001] This utility model belongs to the field of circulating fluidized bed boiler technology, specifically relating to a circulating fluidized bed boiler with combined SCR and SNCR denitrification. Background Technology

[0002] The combined SC and SNCR flue gas denitrification in circulating fluidized bed boilers involves injecting a reducing agent into the furnace for initial NOx removal in the SNCR reactor. Unreacted reducing agent then reacts with the flue gas in the SCR reactor for further catalytic NOx removal. This technology combines the advantages of both SNCR and SCR, achieving efficiency and cost between the two. In small and medium-sized boilers (evaporation capacity less than 450 t / h), the denitrification efficiency is greater than 75%, and the escaped ammonia concentration is less than 5 mg / m³. It offers advantages such as safe operation, high denitrification efficiency, low investment cost, and reduced SCR reactor size.

[0003] When using existing circulating fluidized bed boilers that combine SCR and SNCR for denitrification, ammonia water is loaded into a water tank with a power water pump structure to achieve ammonia water supply and spraying. However, there are the following defects: (1) When ammonia water is loaded into the supply water tank, since the ammonia water is mixed and prepared in the outside world before the water tank is opened and loaded, some external impurity particles will enter the water tank during this process. In the subsequent supply of ammonia water, the impurity particles will be transported to the spray gun assembly in the ammonia water supply system, causing blockage and resulting in insufficient ammonia water spraying volume, which affects the denitrification effect. Therefore, we propose a circulating fluidized bed boiler that combines SCR and SNCR for denitrification. Utility Model Content

[0004] The purpose of this invention is to provide a circulating fluidized bed boiler for combined SCR and SNCR denitrification, in order to solve the problem mentioned in the background art of the circulating fluidized bed boiler for combined SCR and SNCR denitrification being affected by insufficient ammonia spray due to blockage by external impurities, thus affecting the denitrification effect.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a circulating fluidized bed boiler with combined SCR and SNCR denitrification, comprising a furnace and an ammonia supply tank. A cyclone separator is bolted to the outlet of the furnace. A superheated economizing component is connected to the top interface of the cyclone separator via a pipe. An ammonia spray gun assembly for ammonia spraying is provided on the inner wall of the furnace. An outlet is embedded in one side of the ammonia supply tank. A treatment cylinder is welded to the end of the outlet. An ammonia supply pipe is welded between the end of the treatment cylinder and the inlet of the ammonia spray gun assembly. A filter plate is bonded to the inside of the treatment cylinder. A mounting bracket is provided on one side of the filter plate and welded to the inner wall of the treatment cylinder. A rotating column is rotatably embedded in the mounting bracket. An impeller is welded to one end of the rotating column, and a cleaning component is welded to the other end of the rotating column.

[0006] Preferably, the cleaning assembly consists of bristles and a brush plate, wherein the bristles are embedded and laid on the surface of the brush plate.

[0007] Preferably, the bottom sidewall of the processing cylinder is fixed with a slag discharge port by embedding, and a plug is threadedly connected to the port of the slag discharge port.

[0008] Preferably, the inner surface of the rotating column is provided with a spherical groove, and a ball is embedded in the spherical groove.

[0009] Preferably, the longitudinal section of the rotating column is circular, and the cross section of the rotating column is I-shaped.

[0010] Preferably, the central axes of the rotating column, the impeller, and the processing cylinder coincide with each other.

[0011] Preferably, the connection between the mounting frame and the inner wall of the processing cylinder is fixed by welding with a stiffening plate, and the cross-section of the stiffening plate is a triangular structure.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] (1) By designing the treatment cylinder, filter plate, mounting frame, rotating column, and cleaning assembly, a treatment cylinder with a filter structure is installed in the pipeline system supplying ammonia water. When ammonia water flows through the treatment cylinder, the ammonia water containing impurities passes through the filter plate. The filter plate intercepts and filters the impurities in the ammonia water, preventing the impurities from being transported to the ammonia replenishment spray gun assembly and causing blockage of the spray gun nozzle, thus preventing the ammonia water from being sprayed out in sufficient quantity and affecting the denitrification effect. At the same time, during the supply and transportation of ammonia water, the ammonia water impacts the impeller, and under the action of the impact force, the impeller is driven to rotate, which drives the cleaning assembly on the rotating column to clean the filter plate surface. The rotating mechanism sweeps away impurities trapped on the filter plate to prevent clogging. A designed discharge port with a plug is installed on the processing cylinder via a threaded connection. The plug can be unscrewed and removed, and any remaining residue inside the processing cylinder can be cleaned with tools to prevent long-term residue buildup and clogging. Designed ball bearings are embedded in the rotating column surface. As the column rotates, the ball bearings roll on their mounting surface, providing lubrication and preventing friction between the mounting frame and the rotating column surface from hindering rotation. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model;

[0015] Figure 2 This utility model Figure 1 Enlarged view of point A in the image;

[0016] Figure 3 This is a cross-sectional view of the internal structure of the processing cylinder of this utility model;

[0017] Figure 4 This is a three-dimensional assembly view of the processing cylinder, mounting frame, and rotating column of this utility model;

[0018] In the diagram: 1. Furnace; 2. Ammonia water supply pipe; 3. Cyclone separator; 4. Superheated economizer assembly; 5. Ammonia water supply tank; 6. Water outlet; 7. Plug; 8. Slag discharge port; 9. Processing cylinder; 10. Filter plate; 11. Rib plate; 12. Mounting frame; 13. Impeller; 14. Rotating column; 15. Ball bearing; 16. Cleaning assembly; 17. Brush bristles; 18. Brush plate. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] Example

[0021] Please see Figures 1 to 4 This utility model provides a technical solution: a circulating fluidized bed boiler with combined SCR and SNCR denitrification, including a furnace 1 and an ammonia supply tank 5. A cyclone separator 3 is bolted to the outlet of the furnace 1. A superheated economizing component 4 is connected to the top interface of the cyclone separator 3 via a pipe. An ammonia spray gun assembly for ammonia spraying is provided on the inner wall of the furnace 1. An outlet 6 is embedded in one side of the ammonia supply tank 5. A treatment cylinder 9 is welded to the end of the outlet 6. An ammonia supply pipe 2 is welded between the end of the treatment cylinder 9 and the inlet of the ammonia spray gun assembly. A filter plate 10 is bonded to the inside of the treatment cylinder 9. A mounting bracket 12 is provided on the outside of one side of the filter plate 10 and is welded to the inner wall of the treatment cylinder 9. A rotating column 14 is rotatably embedded in the mounting bracket 12. An impeller 13 is welded to one end of the rotating column 14. The other end of the rotating column 14 is fixed with a cleaning assembly 16 by welding. The cleaning assembly 16 consists of bristles 17 and a brush plate 18. The bristles 17 are embedded and laid on the surface of the brush plate 18. Through the designed treatment cylinder 9, filter plate 10, mounting frame 12, rotating column 14 and cleaning assembly 16, the treatment cylinder 9 with a filter structure is installed in the pipeline system supplying ammonia water. When ammonia water flows through the treatment cylinder 9, the ammonia water with impurities passes through the filter plate 10. The filter plate 10 intercepts and filters the impurities in the ammonia water, preventing the impurities from being transported to the ammonia replenishment spray gun assembly and causing blockage of the spray gun nozzle, which would prevent the ammonia water from being sprayed out in sufficient quantity and affect the denitrification effect. At the same time, during the supply and transportation of ammonia water, the ammonia water impacts the impeller 13. Under the action of the impact force, the impeller 13 is driven to rotate, which drives the cleaning assembly 16 on the rotating column 14 to rotate on the surface of the filter plate 10, cleaning away the impurities intercepted on the filter plate 10, so as to prevent the filter plate 10 from becoming blocked.

[0022] In this embodiment, preferably, the bottom side wall of the processing cylinder 9 is fixed with a slag discharge port 8 by embedding, and a plug 7 is threadedly connected to the port of the slag discharge port 8. By designing the slag discharge port 8 and the plug 7, the slag discharge port 8 with the plug 7 screwed on is set onto the processing cylinder 9. The plug 7 can be screwed off and the residue remaining in the processing cylinder 9 can be removed and cleaned with tools to avoid the long-term accumulation of residue that may cause blockage of the processing cylinder 9.

[0023] In this embodiment, preferably, a spherical groove is formed on the inner surface of the rotating column 14, and a ball bearing 15 is embedded in the spherical groove. The ball bearing 15 is designed to roll and be embedded on the surface of the rotating column 14. When the rotating column 14 rotates, the ball bearing 15 rolls on the surface of its mounting frame 12, which plays a lubricating role and avoids the friction between the mounting frame 12 and the surface of the rotating column 14 from hindering the rotation. The longitudinal section of the rotating column 14 is a circular structure, and the cross section of the rotating column 14 is an I-shaped structure. The central axes of the rotating column 14, the impeller 13, and the processing cylinder 9 coincide with each other.

[0024] In this embodiment, preferably, a stiffening plate 11 is welded to the connection between the inner wall of the mounting frame 12 and the treatment cylinder 9. The stiffening plate 11 is designed and welded to the connection between the mounting frame 12 and the treatment cylinder 9 to reinforce the connection and prevent cracking and deformation at the connection between the mounting frame 12 and the treatment cylinder 9 from affecting the cleaning function of the cleaning component. The cross-section of the stiffening plate 11 is a triangular structure.

[0025] The working principle and usage process of this utility model: A circulating fluidized bed boiler with combined SCR and SNCR denitrification is used for denitrification treatment. The boiler consists of an SNCR denitrification reaction zone and an SCR denitrification reaction zone. In the SNCR zone, ammonia water is directly injected into the furnace to meet the temperature window area and remove part of the NOx. The generated ammonia enters the SCR zone at the rear end along with the flue gas. Under the action of the catalyst, it reacts with NOx again and removes NOx. The combined SNCR and SCR denitrification process combines the advantages of low investment of selective non-catalytic reduction (SNCR) and high denitrification efficiency of selective catalytic reduction (SCR), and solves the problem of high NOx concentration in boilers and the inability to achieve ultra-low emissions by relying solely on SCR or SNCR processes.

[0026] In this invention, ammonia water is loaded into an ammonia water supply tank 5, and transported by a pump within the tank 5 to the ammonia water supply pipe 2, and then sprayed into the ammonia replenishment spray gun. When the ammonia water flows through the treatment cylinder 9, the ammonia water containing impurities passes through the filter plate 10. The filter plate 10 intercepts and filters the impurities in the ammonia water, preventing them from being transported to the ammonia replenishment spray gun assembly and clogging the nozzle, thus ensuring sufficient ammonia water is sprayed out and affecting the denitrification effect. Simultaneously, during the supply and transport of ammonia water, the ammonia water impacts the blades. The impeller 13 is driven to rotate under the action of impact force, which drives the cleaning component 16 on the rotating column 14 to rotate on the surface of the filter plate 10, cleaning the impurities intercepted on the filter plate 10 to avoid clogging of the filter plate 10. When the descaling operation stops, the slag discharge port 8 with the plug 7 installed by screwing it on is set on the processing cylinder 9. The plug 7 can be screwed off and the residue remaining in the processing cylinder 9 can be removed and cleaned with tools to avoid the long-term accumulation of residue that may cause clogging of the processing cylinder 9.

[0027] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A circulating fluidized bed boiler with combined SCR and SNCR denitrification, comprising a furnace (1) and an ammonia supply tank (5), wherein a cyclone separator (3) is bolted to the outlet of the furnace (1), and a superheated economizing assembly (4) is connected to the top interface of the cyclone separator (3) via a pipe; an ammonia spray gun assembly for ammonia spraying is provided on the inner wall of the furnace (1); and an outlet (6) is embedded on one side of the ammonia supply tank (5), characterized in that: The end of the outlet (6) is fixed with a treatment cylinder (9) by welding. An ammonia supply pipe (2) is connected between the end of the treatment cylinder (9) and the inlet of the ammonia spray gun assembly by welding. A filter plate (10) is fixed inside the treatment cylinder (9) by adhesive bonding. An mounting bracket (12) is provided on one side of the filter plate (10), and the mounting bracket (12) is fixed to the inner wall of the treatment cylinder (9) by welding. A rotating column (14) is rotatably embedded on the mounting bracket (12). One end of the rotating column (14) is fixed with an impeller (13) by welding, and the other end of the rotating column (14) is fixed with a cleaning assembly (16) by welding.

2. A circulating fluidized bed boiler with combined SCR and SNCR denitrification according to claim 1, characterized in that: The cleaning assembly (16) consists of bristles (17) and a brush plate (18), wherein the bristles (17) are embedded onto the surface of the brush plate (18).

3. A circulating fluidized bed boiler with combined SCR and SNCR denitrification according to claim 1, characterized in that: The bottom side wall of the processing cylinder (9) is fixed with a slag discharge port (8) by embedding, and a plug (7) is connected to the port of the slag discharge port (8) by thread.

4. A circulating fluidized bed boiler with combined SCR and SNCR denitrification according to claim 1, characterized in that: The inner surface of the rotating column (14) is provided with a spherical groove, and a ball (15) is embedded in the spherical groove.

5. A circulating fluidized bed boiler with combined SCR and SNCR denitrification according to claim 1, characterized in that: The longitudinal section of the rotating column (14) is circular, and the cross section of the rotating column (14) is I-shaped.

6. A circulating fluidized bed boiler with combined SCR and SNCR denitrification according to claim 1, characterized in that: The central axes of the rotating column (14), the impeller (13), and the processing cylinder (9) coincide with each other.

7. A circulating fluidized bed boiler with combined SCR and SNCR denitrification according to claim 1, characterized in that: The inner wall connection between the mounting bracket (12) and the processing cylinder (9) is fixed by welding with a stiffening plate (11), and the cross section of the stiffening plate (11) is a triangular structure.

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