Cross-shaped ammonia spraying device suitable for SCR denitration system of conventional grate-fired furnace

Abstract

The utility model discloses a cross-shaped ammonia spraying device suitable for a conventional grate-fired furnace SCR (Selective Catalytic Reduction) denitration system, which relates to the technical field of SCR denitration, and comprises an ammonia gas conveying pipe and a flow equalizing distribution pipe, the flow equalizing distribution pipe comprises a distribution ring pipe and a plurality of ammonia spraying pipes, the distribution ring pipe is positioned above the ammonia gas conveying pipe and is communicated with the ammonia gas conveying pipe through a connecting branch pipe, and the ammonia spraying pipes are communicated with the ammonia gas conveying pipe through a connecting branch pipe. The multiple ammonia spraying pipes are arranged on the outer side wall of the distribution ring pipe in a cross shape and are all communicated with the interior of the distribution ring pipe, and each ammonia spraying pipe is provided with an ammonia gas ejector; the ammonia spraying pipes arranged in the cross shape can distribute ammonia gas more evenly, the contact area of the ammonia gas and flue gas is increased, the mixing uniformity of the ammonia gas and the flue gas is improved, the ammonia gas is evenly distributed to all the ammonia spraying pipes through the distribution ring pipe, it is ensured that the ammonia gas is evenly distributed, and the situation that the local ammonia gas concentration is too high or too low is avoided; according to the utility model, the mixing uniformity can be improved, the contact area is increased, the cost is reduced, the denitration efficiency is improved, and the flue gas treatment requirement of the conventional grate-fired furnace can be met.

Description

Technical Field

[0001] This utility model relates to the field of SCR denitrification technology, and more specifically to a cross-shaped ammonia injection device suitable for conventional stoker SCR denitrification systems. Background Technology

[0002] Stoker-fired boilers are a common type of industrial boiler, mainly used for burning fuels (such as coal, biomass, etc.) to produce high-temperature flue gas. Flue gas emissions are one of the sources of air pollution, and the nitrogen oxides (NOx) they contain have a serious impact on the environment and human health. Selective catalytic reduction (SCR) denitrification technology is widely used in industrial boiler flue gas treatment due to its high denitrification performance. By injecting ammonia into the flue gas, it reacts with the NOx in the flue gas under the action of a catalyst to produce nitrogen and water, and the denitrification efficiency can reach 90%.

[0003] In existing desulfurization systems using stoker-fired furnaces, conventional stoker-fired furnaces have relatively small flue gas processing capacities and relatively stable flue gas flow characteristics. However, existing ammonia removal devices often cannot provide sufficient contact area, resulting in inadequate mixing of ammonia and flue gas, thus affecting ammonia removal efficiency. Furthermore, for conventional stoker-fired furnaces, complex and costly ammonia removal devices are not economical or practical.

[0004] For example, the prior art with patent number CN201120523576.8 discloses a flue gas denitrification ammonia injection grid. The device includes a first connecting pipe, a resistance distribution pipe, and a second connecting pipe. The second connecting pipe is connected to the first connecting pipe through the resistance distribution pipe. Multiple nozzles are provided on the second connecting pipe, and each nozzle has a flue gas disturbance plate at its jet port. Although this structure is relatively simple, it can only reduce the mixing distance between ammonia and flue gas at the inlet of the denitrification reactor, and cannot achieve uniform mixing of flue gas and ammonia.

[0005] Therefore, how to provide a cross-shaped ammonia removal device that is simple in structure, ensures uniform ammonia injection, and is suitable for conventional stoker SCR denitrification systems is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0006] In view of this, the present invention provides a cross-shaped ammonia injection device suitable for conventional stoker SCR denitrification systems, aiming to solve the above-mentioned technical problems.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A cross-shaped ammonia injection device suitable for conventional stoker SCR denitrification systems includes:

[0009] Ammonia gas delivery pipe,

[0010] The flow equalization distribution pipe includes a distribution ring pipe and multiple ammonia injection pipes. The distribution ring pipe is located above the ammonia delivery pipe and is connected to the ammonia delivery pipe through a connecting branch pipe. The multiple ammonia injection pipes are arranged in a cross shape on the outer wall of the distribution ring pipe and are all connected to the interior of the distribution ring pipe. Each ammonia injection pipe is equipped with an ammonia injector.

[0011] Through the above technical solution, this utility model provides a cross-shaped ammonia injection device suitable for conventional stoker SCR denitrification systems. The cross-shaped arrangement of the ammonia injection pipes can distribute ammonia more evenly, increasing the contact area between ammonia and flue gas, thereby improving the mixing uniformity of ammonia and flue gas and helping to improve the mixing efficiency between ammonia and flue gas, thus improving the denitrification efficiency. By using a distribution ring pipe to evenly distribute ammonia to each ammonia injection pipe, it ensures the uniform distribution of ammonia in the entire denitrification system and avoids local ammonia concentrations that are too high or too low. This utility model can improve mixing uniformity, increase contact area, reduce costs, and improve denitrification efficiency, and can meet the flue gas treatment needs of conventional stoker furnaces, while not requiring complex structures or high costs.

[0012] Preferably, in the aforementioned cross-shaped ammonia injection device suitable for a conventional stoker-fired SCR denitrification system, the orifice diameter of the ammonia delivery pipe is larger than that of the distribution ring pipe and the ammonia injection pipe; the orifice diameter of the distribution ring pipe is larger than that of the connecting branch pipe. By designing different pipe diameters, the ammonia flow path is optimized, flow resistance is reduced, and the efficiency of ammonia delivery is improved; ensuring the stability of ammonia during delivery helps to improve the overall performance of the denitrification system.

[0013] Preferably, in the aforementioned cross-shaped ammonia injection device suitable for a conventional stoker SCR denitrification system, each ammonia injection pipe is equipped with multiple ammonia injectors. Installing multiple ammonia injectors on each injection pipe increases the number of ammonia injection points, further improving the uniformity of ammonia mixing with flue gas; this helps improve denitrification efficiency and may reduce ammonia escape, thus lowering environmental pollution.

[0014] Preferably, in the aforementioned cross-shaped ammonia injection device suitable for a conventional stoker SCR denitrification system, multiple ammonia injectors are arranged obliquely on the ammonia injection pipe, and the oblique angle of the multiple ammonia injectors increases sequentially along the length of the ammonia injection pipe from the end closest to the distribution ring pipe. By arranging the ammonia injectors obliquely, the injection angle and coverage of ammonia are optimized, enhancing the mixing effect; this helps to improve denitrification efficiency, while reducing the uneven distribution of ammonia in the flue gas and lowering the risk of ammonia escape.

[0015] Preferably, in the aforementioned cross-shaped ammonia injection device suitable for a conventional stoker SCR denitrification system, the angle between the ammonia injector near the distribution ring pipe and the vertical direction is 40°, and the angle between the ammonia injector away from the distribution ring pipe and the vertical direction is no greater than 50°. By precisely controlling the injection angle, ammonia waste can be reduced and ammonia utilization rate can be improved.

[0016] Preferably, in the aforementioned cross-shaped ammonia injection device suitable for a conventional stoker SCR denitrification system, each ammonia injection pipe is equipped with two rows of ammonia injectors. Arranging two rows of ammonia injectors on each ammonia injection pipe increases the number of injection points and improves the uniformity of ammonia distribution.

[0017] Preferably, in the aforementioned cross-shaped ammonia injection device suitable for a conventional stoker-fired SCR denitrification system, the ammonia injector includes a nozzle, a connecting shaft, and a driven impeller. The bottom end of the nozzle is connected to the ammonia injection pipe, and a ring-shaped injection port is formed on the top end face. The bottom end of the connecting shaft is detachably connected to the center of the top end face of the nozzle, and the driven impeller rotates on the top end of the connecting shaft. The rotation of the driven impeller further disperses the ammonia gas, increasing the contact area between the ammonia gas and the flue gas, thereby improving the denitrification efficiency.

[0018] Preferably, in the aforementioned cross-shaped ammonia injection device suitable for a conventional stoker SCR denitrification system, the driven impeller includes an impeller body rotatably connected to the top of the connecting shaft, and multiple blades fixed on the impeller body. Since the flue gas flows upwards at a relatively high velocity, it can drive the driven impeller to rotate around the connecting shaft. The rotation of the blades creates gas turbulence, forming a turbulence zone near the nozzle, which can reduce fly ash accumulation and clogging of the injection port. This not only enhances the uniformity of the mixing of flue gas and ammonia, saving ammonia consumption, but also effectively prevents ash accumulation and nozzle clogging.

[0019] Preferably, in the aforementioned cross-shaped ammonia injection device suitable for a conventional stoker-fired SCR denitrification system, the bottom end of the connecting shaft is threadedly connected to the center of the end face of the top end of the injection pipe. This threaded connection of the connecting shaft improves the stability and reliability of the structure, facilitates installation and maintenance, and helps improve the durability of the device, reduce maintenance costs, and enhance the reliability of the denitrification system.

[0020] Preferably, in the aforementioned cross-shaped ammonia injection device suitable for a conventional stoker SCR denitrification system, an electromagnetic flow valve is installed on the ammonia delivery pipe. Installing an electromagnetic flow valve on the ammonia delivery pipe allows for precise control of the ammonia flow rate, which helps improve the control accuracy and efficiency of the denitrification process. Precise flow control helps optimize denitrification efficiency while reducing ammonia waste and increasing ammonia utilization.

[0021] As can be seen from the above technical solution, compared with the prior art, this utility model discloses a cross-shaped ammonia injection device suitable for conventional stoker SCR denitrification systems, which has the following beneficial effects:

[0022] 1. This utility model uses a cross-shaped ammonia injection pipe to distribute ammonia gas more evenly, increasing the contact area between ammonia gas and flue gas, thereby improving the mixing uniformity of ammonia gas and flue gas and helping to improve denitrification efficiency.

[0023] 2. This utility model uses a distribution ring pipe to evenly distribute ammonia gas to each ammonia injection pipe, ensuring the uniform distribution of ammonia gas throughout the denitrification system and avoiding excessively high or low local ammonia gas concentrations.

[0024] 3. This utility model installs multiple ammonia injectors on each ammonia injection pipe, increasing the number of ammonia injection points and further improving the uniformity of ammonia mixing with flue gas, which helps to improve denitrification efficiency and may reduce ammonia escape and environmental pollution.

[0025] 4. This utility model improves the uniformity of ammonia mixing with flue gas and denitrification efficiency by optimizing the distribution and injection method of ammonia gas, while reducing costs and maintenance difficulty. It is suitable for conventional stoker SCR denitrification systems. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 The attached figure is an isometric view of the cross-shaped ammonia injection device for a conventional stoker SCR denitrification system provided by this utility model;

[0028] Figure 2 The attached figure is a top view of the cross-shaped ammonia injection device for a conventional stoker SCR denitrification system provided by this utility model;

[0029] Figure 3 The attached figure is a front view of the cross-shaped ammonia injection device for a conventional stoker SCR denitrification system provided by this utility model;

[0030] Figure 4 The attached figure is a structural schematic diagram of the ammonia injector provided by this utility model.

[0031] in:

[0032] 1-Ammonia delivery pipe; 2-Distribution ring pipe; 3-Ammonia injection pipe; 4-Connecting branch pipe; 5-Ammonia injector; 51-Injection pipe; 511-Injection port; 52-Connecting shaft; 53-Driven impeller; 531-Impeller body; 532-Blade; 6-Solenoid flow valve. Detailed Implementation

[0033] 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.

[0034] See appendix Figure 1 To be continued Figure 4 This utility model discloses a cross-shaped ammonia injection device suitable for a conventional stoker SCR denitrification system, which is installed in the flue gas passage of the conventional stoker furnace, and includes:

[0035] Ammonia gas delivery pipe 1,

[0036] The flow distribution pipe includes a distribution ring pipe 2 and multiple ammonia injection pipes 3. The distribution ring pipe 2 is located above the ammonia delivery pipe 1 and is connected to the ammonia delivery pipe 1 through a connecting branch pipe 4. The multiple ammonia injection pipes 3 are arranged in a cross shape on the outer wall of the distribution ring pipe 2 and are all connected to the inside of the distribution ring pipe 2. Each ammonia injection pipe 3 is equipped with an ammonia injector 5.

[0037] To further optimize the above technical solution, the orifice diameter of the ammonia delivery pipe 1 is larger than that of the distribution ring pipe 2 and the ammonia injection pipe 3; the orifice diameter of the distribution ring pipe 2 is larger than that of the connecting branch pipe 4.

[0038] To further optimize the above technical solution, multiple ammonia injectors 5 are installed on each ammonia injection pipe 3.

[0039] To further optimize the above technical solution, multiple ammonia injectors 5 are arranged at an angle on the ammonia injection pipe 3, and the angle of inclination of the multiple ammonia injectors 5 increases sequentially from the end closest to the distribution ring pipe 2 along the length of the ammonia injection pipe 3.

[0040] To further optimize the above technical solution, the angle between the ammonia injector 5 near the distribution ring pipe 2 and the vertical direction is 40°, and the angle between the ammonia injector 5 away from the distribution ring pipe 2 and the vertical direction is no greater than 50°.

[0041] To further optimize the above technical solution, two rows of ammonia injectors 5 are arranged on each ammonia injection pipe 3.

[0042] To further optimize the above technical solution, the ammonia injector 5 includes a nozzle 51, a connecting shaft 52, and a driven impeller 53. The bottom end of the nozzle 51 is connected to the ammonia injection pipe 3, and a ring-shaped injection port 511 is opened on the end face of the top end. The bottom end of the connecting shaft 52 is detachably connected to the center of the end face of the top end of the nozzle 51, and the driven impeller 53 rotates on the top end of the connecting shaft 52.

[0043] To further optimize the above technical solution, the driven impeller 53 includes an impeller body 531 rotatably connected to the top of the connecting shaft 52, and a plurality of blades 532 fixed on the impeller body 531.

[0044] To further optimize the above technical solution, the bottom end of the connecting shaft 52 is threadedly connected to the center of the end face of the nozzle 51.

[0045] To further optimize the above technical solution, an electromagnetic flow valve 6 is installed on the ammonia gas delivery pipe 1.

[0046] It should be noted that the conventional stoker-fired boiler has a moderate flue gas flow rate, a symmetrical combustion chamber layout, and a moderate size. The four ammonia injection ports, designed in a cross shape, are evenly distributed, forming symmetrical coverage in the horizontal direction and maximizing the mixing efficiency of ammonia and flue gas. The coverage area of ​​the cross-shaped ammonia injection matches the cross-sectional area of ​​the conventional boiler, which avoids incomplete desulfurization due to insufficient injection intensity and prevents resource waste caused by redundant design.

[0047] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0048] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cross-shaped ammonia injection device suitable for a conventional grate SCR denitration system, characterized in that, The utility model relates to a kind of ammonia delivery pipe (1), flow distribution pipe, which includes distribution ring pipe (2) and multiple ammonia injection pipe (3), distribution ring pipe (2) is located above ammonia delivery pipe (1), and is communicated with ammonia delivery pipe (1) by connecting branch pipe (4), multiple ammonia injection pipe (3) is arranged in the outer wall of distribution ring pipe (2) in cross shape, and each ammonia injection pipe (3) is equipped with ammonia injector (5). The aperture of the ammonia delivery pipe (1) is larger than the aperture of the distribution ring pipe (2) and the ammonia injection pipe (3);The aperture of the distribution ring pipe (2) is larger than the aperture of the connecting branch pipe (4). Each ammonia injection pipe (3) is equipped with multiple ammonia injectors (5).

2. The cross-shaped ammonia injection device suitable for the SCR denitration system of the conventional grate furnace according to claim 1, characterized in that, Multiple ammonia injectors (5) are arranged on the ammonia injection pipe (3) in an inclined manner, and the inclination angles of multiple ammonia injectors (5) increase in turn along the length direction of the ammonia injection pipe (3) from one end close to the distribution ring pipe (2).

3. The cross-shaped ammonia injection device suitable for the SCR denitration system of the conventional grate furnace according to claim 1, characterized in that, The angle between the ammonia injector (5) close to one end of the distribution ring pipe (2) and the vertical direction is 40°, and the angle between the ammonia injector (5) away from one end of the distribution ring pipe (2) and the vertical direction is not greater than 50°.

4. The cross-shaped ammonia injection device suitable for the SCR denitration system of the conventional grate furnace according to claim 3, characterized in that, Each ammonia injection pipe (3) is arranged with two rows of ammonia injectors (5).

5. The cross-shaped ammonia injection device suitable for the SCR denitration system of the conventional grate furnace according to claim 4, characterized in that, The ammonia injector (5) includes a nozzle (51), a connecting shaft (52), and a driven impeller (53). The bottom end of the nozzle (51) is communicated with the ammonia injection pipe (3), and the top end is provided with a ring-shaped injection port (511). The bottom end of the connecting shaft (52) is detachably connected to the center of the top end of the nozzle (51), and the driven impeller (53) is rotatably arranged on the top end of the connecting shaft (52).

6. The cross-shaped ammonia injection device suitable for the SCR denitration system of the conventional grate furnace according to claim 1, characterized in that, The driven impeller (53) includes an impeller body (531) rotatably connected to the top end of the connecting shaft (52), and multiple blades (532) fixed on the impeller body (531).

7. The cross-shaped ammonia injection device suitable for the SCR denitration system of the conventional grate furnace according to claim 1, characterized in that, The bottom end of the connecting shaft (52) is threadedly connected to the center of the top end of the nozzle (51).

8. The cross-shaped ammonia injection device suitable for the SCR denitration system of the conventional grate furnace according to claim 7, characterized in that, The ammonia delivery pipe (1) is equipped with an electromagnetic flow valve (6).

9. The cross-shaped ammonia injection device suitable for the SCR denitration system of the conventional grate furnace according to claim 7, characterized in that, ​ 10. The cross-shaped ammonia injection device suitable for the SCR denitration system of the conventional grate furnace according to claim 1, characterized in that, ​

Images