An extended spiral nozzle ammonia spray grid

Abstract

The utility model discloses an extended spiral nozzle ammonia spraying grid, which is suitable for high-dust flue gas, including a nozzle, the nozzle is in a spiral shape, the nozzle is equipped with a base, the nozzle and the base are threadedly connected, the base is fixed on an extended pipe by welding, and the extended pipe is fixed on the branch pipe of the ammonia spraying grid; due to the special structure of the extended spiral nozzle, the utility model can operate stably in high-dust flue gas, solves the problem that conventional nozzles are easily blocked by dust in the flue gas, and solves the problem that the ammonia-air mixture sprayed by the conventional nozzle cannot fully contact with the flue gas. The extended spiral nozzle ammonia spraying grid has the characteristics of anti-blocking, and has a significant anti-blocking effect when used in the SCR denitrification ultra-low emission transformation.

Description

Technical Field

[0001] The utility model relates to the technical field of ultra-low emission of flue gas SCR denitration, and in particular to an extended spiral nozzle type ammonia spraying grid. Background Art

[0002] At present, the development of flue gas denitrification is particularly important. The current mainstream denitrification processes include SNCR, SCR, and SNCR+SCR. The form of the ammonia spray grid nozzle in SCR directly affects the denitrification efficiency. Traditional ammonia spray grid nozzles have a series of problems during use.

[0003] The nozzle length of the traditional ammonia spraying grid is relatively short, and the dust in the flue gas is easy to pile up and climb on the top of the ammonia spraying branch pipe, which can easily cause the nozzle to be blocked and there is a problem of uneven mixing with the flue gas, which indirectly causes excessive ammonia spraying;

[0004] If excessive ammonia is sprayed, it will not have enough time to react and will easily generate ammonium bisulfate, which will clog the air preheater and cause high differential pressure in the air preheater, which will in turn cause high energy consumption of the induced draft fan and other problems. It will also cause corrosion to the equipment at the reactor outlet and affect its service life. Utility Model Content

[0005] The utility model aims to solve the shortcomings of the prior art and proposes an extended spiral nozzle type ammonia spray grid, comprising a nozzle, and an extended pipe is arranged at the front end of the nozzle;

[0006] The nozzle is provided with a base, and the nozzle and the base are connected by thread;

[0007] The base is fixedly mounted on an extension pipe, and the extension pipe is fixed on an ammonia injection grid branch pipe.

[0008] Preferably, the nozzle is spiral-shaped.

[0009] Preferably, the base is fixedly welded to the extension tube.

[0010] Preferably, the base is threadedly connected to the extension tube.

[0011] Preferably, the length of the extension tube is determined by flow field simulation.

[0012] Preferably, the inner diameter of the extension tube is determined by the selection of the nozzle base.

[0013] Compared with the existing technology, the beneficial effects of the utility model are:

[0014] 1. Spiral nozzle, with large spray angle, has better spray diffusion and anti-dust performance;

[0015] 2. The end of the ammonia spray branch pipe is made into a threaded form, which can better repair and replace the nozzle, solving the problem that the traditional ammonia spray hole is difficult to remove for maintenance;

[0016] 3. The number of nozzles of the extended spiral nozzle ammonia spray grid is greatly increased compared with the traditional form, which enhances the uniformity of the initial distribution of the cross section and is conducive to better mixing of the ammonia / air mixture and the flue gas;

[0017] 4. Improve the distribution uniformity of NOx concentration at the SCR inlet under different loads of the unit and improve the load adaptability of the AIG unit;

[0018] 5. According to the CFD numerical flow field simulation results, an extended spiral nozzle ammonia spray grid is selected. In the daily operation of SCR denitrification, further ammonia spray optimization and adjustment tests can be performed to greatly reduce the NOx distribution deviation at the reactor outlet section, which improves the performance of the denitrification device to a certain extent, extends the service life of the catalyst, saves resources, and reduces operating costs.

[0019] Due to the special structure of the extended spiral nozzle, it can operate stably in high-dust flue gas, solving the problem that conventional nozzles are easily blocked by dust in the flue gas, and solving the problem that the ammonia-air mixture sprayed through the conventional nozzle cannot fully contact the flue gas. The extended spiral nozzle ammonia spray grid has the characteristics of anti-clogging, and has a significant anti-clogging effect when used in the SCR denitrification ultra-low emission transformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the layout location diagram of the utility model;

[0021] Figure 2 This is the front view of the structure of the utility model;

[0022] Figure 3 for Figure 2 Medium AA image.

[0023] In the figure: No. 1 is the nozzle, No. 2 is the base, No. 3 is the extension pipe, and No. 4 is the ammonia injection grid branch pipe. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0025] Referring to the figure, this embodiment provides an extended spiral nozzle type ammonia spray grid, including a nozzle 1, and an extended pipe 3 is provided at the front end of the nozzle 1;

[0026] The nozzle 1 is provided with a base 2, and the nozzle 1 and the base 2 are connected by thread;

[0027] The base 2 is fixedly mounted on the extension pipe 3 , and the extension pipe 3 is fixed on the ammonia injection grid branch pipe 4 .

[0028] Furthermore, the nozzle 1 is in a spiral shape. The spiral nozzle has a large spray angle and has better spray diffusion and dust blocking performance.

[0029] Furthermore, there are many ways to connect the base 2 and the extension tube, such as the base 2 is fixedly welded to the extension tube 3; such as the base 2 is threaded to the extension tube 3. In addition, there are other ways to connect, which will not be described one by one here.

[0030] Furthermore, the length of the extension tube 3 is determined by flow field simulation; the inner diameter of the extension tube 3 is determined by the selection of the nozzle 1 base; that is: according to the flow field simulation results, combined with the nozzle 1 selection, the extension tube 3 that meets the requirements is selected.

[0031] More specifically, the extended spiral nozzle ammonia injection grid is directly arranged in the inlet flue of the SCR denitration reactor. As shown in the figure, it is arranged in the vertical flue. The extended spiral nozzle ammonia injection grid can also be arranged in the horizontal flue.

[0032] Since the installation position of the ammonia spray grid is located in a high dust section, conventional nozzles are prone to clogging, especially when the nozzles are vertically upward, and dust is easily accumulated on the leeward side of the ammonia spray branch pipe. In this situation, the nozzle selection should have the ability to be extended and prevent clogging. Therefore, the material of the extended spiral nozzle type ammonia spray grid of the utility model can be selected as 304 or 316L according to the type of reducing agent. Therefore, the nozzle 1 of this invention is spiral-shaped, and the nozzle 1 is equipped with a base 2. The nozzle 1 and the base 2 are connected by threading. The base 2 is fixed to the extension pipe 3 by welding, and the extension pipe 3 is fixed to the ammonia spray grid branch pipe 4.

[0033] In the above embodiment, due to the spiral nozzle, the injection angle is large, and it has better injection diffusion and anti-ash blocking performance; the end of the ammonia injection branch pipe is made into a threaded form, so the nozzle can be better inspected and replaced, which solves the problem that the traditional ammonia injection hole is not convenient to remove for inspection; the number of nozzles of the extended spiral nozzle ammonia injection grid is greatly increased compared with the traditional form, which enhances the uniformity of the initial distribution of the cross-section, and is conducive to better mixing of the ammonia / air mixture and the flue gas; improves the distribution uniformity of the NOx concentration at the SCR inlet under different loads of the unit, and improves the unit load adaptability of the AIG; according to the CFD numerical flow field simulation results, the extended spiral nozzle ammonia injection grid is selected. In the daily operation of SCR denitrification, through further ammonia injection optimization and adjustment tests, the NOx distribution deviation of the reactor outlet cross section can be greatly reduced, which improves the performance of the denitrification device to a certain extent, extends the service life of the catalyst, saves resources, and reduces operating costs.

[0034] Due to the special structure of the extended spiral nozzle, it can operate stably in high-dust flue gas, solving the problem that conventional nozzles are easily blocked by dust in the flue gas, and solving the problem that the ammonia-air mixture sprayed through the conventional nozzle cannot fully contact the flue gas. The extended spiral nozzle ammonia spray grid has the characteristics of anti-clogging, and has a significant anti-clogging effect when used in the SCR denitrification ultra-low emission transformation.

[0035] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An extended spiral nozzle ammonia spray grid, characterized in that: It comprises a nozzle (1), the front end of the nozzle (1) being provided with an extension tube (3); The nozzle (1) is provided with a base (2), and the nozzle (1) and the base (2) are connected by thread; The base (2) is fixedly mounted on an extension pipe (3), and the extension pipe (3) is fixed on an ammonia injection grid branch pipe (4).

2. The extended spiral nozzle ammonia spray grid according to claim 1, characterized in that: The nozzle is in a spiral shape.

3. The extended spiral nozzle ammonia spray grid according to claim 1, characterized in that: The base (2) is fixedly welded on the extension tube (3).

4. The extended spiral nozzle ammonia spray grid according to claim 1, characterized in that: The base (2) is threadedly connected to the extension tube (3).

5. The extended spiral nozzle ammonia spray grid according to claim 1, characterized in that: The length of the extension tube (3) is determined through flow field simulation.

6. The extended spiral nozzle ammonia spray grid according to claim 1, characterized in that: The inner diameter of the extension tube (3) is determined by the selection of the nozzle (1) base.

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