Annular ammonia spraying device suitable for SCR denitration system of large grate-fired furnace

Abstract

The utility model discloses an annular ammonia spraying device suitable for a large grate-fired furnace SCR denitration system, and relates to the technical field of SCR denitration, the annular ammonia spraying device comprises a plurality of annular ammonia spraying pipes, the annular ammonia spraying pipes are concentrically nested, each annular ammonia spraying pipe is provided with an ammonia injector, the injection direction of the ammonia injectors is arranged towards the adjacent annular ammonia spraying pipes, and the annular ammonia spraying pipes are communicated with the adjacent annular ammonia spraying pipes. Cross coverage is formed; the ammonia gas conveying pipe is communicated with the annular ammonia spraying pipes through conveying branch pipes, the contact area of ammonia gas and flue gas is increased through concentric nesting arrangement of the annular ammonia spraying pipes, the mixing uniformity is improved, the spraying direction of the ammonia gas sprayer is arranged towards the adjacent annular ammonia spraying pipes, and the mixing uniformity is improved. Cross coverage of an ammonia gas spraying path is formed, so that a denitration blind area in the section of the flue is effectively eliminated, and the denitration efficiency is improved; graded ammonia supply is achieved through the ammonia conveying pipe and the conveying branch pipes, ammonia pressure balance is guaranteed, and insufficient local flow is avoided. The structure is suitable for the SCR denitration system of the large grate-fired furnace.

Description

Technical Field

[0001] This utility model relates to the field of SCR denitrification technology, and more specifically to an annular ammonia injection device suitable for large-scale stoker SCR denitrification systems. Background Technology

[0002] With increasingly stringent environmental protection requirements, stoker desulfurization systems are being used more and more widely in the industrial sector. Large-scale stoker furnaces, in particular, occupy an important position in industries such as power, chemical, and steel due to their advantages of large processing capacity and high efficiency. However, large-scale stoker furnaces generate a large amount of flue gas during operation, and the flue gas flow characteristics are relatively complex. Existing ammonia injection devices generally suffer from the following technical defects:

[0003] Linear or simply branched ammonia removal units have relatively small contact areas between the ammonia injection pipes and the flue gas, resulting in insufficient mixing of ammonia and flue gas. This prevents 360° continuous coverage of the flue gas duct cross-section, especially in scenarios with large flue gas flow rates and spacious areas, where edge areas are prone to forming desulfurization dead zones, leading to localized excessive sulfide residues. In large stoker-fired furnaces, the flue gas volume is enormous. If the contact area is insufficient, ammonia cannot mix fully with the flue gas in a short time, thus affecting denitrification efficiency. Furthermore, large stoker-fired furnace desulfurization systems have high requirements for space utilization and structural compactness, which existing ammonia removal units may not be able to meet.

[0004] Therefore, how to provide a ring-shaped ammonia injection device suitable for large-scale SCR denitrification systems with wide coverage, improved contact area and mixing uniformity is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, the present invention provides an annular ammonia injection device suitable for large-scale stoker SCR denitrification systems, aiming to solve the above-mentioned technical problems.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A ring-shaped ammonia injection device suitable for a large-scale stoker SCR denitrification system includes:

[0008] Multiple annular ammonia injection pipes are arranged concentrically, and each annular ammonia injection pipe is equipped with an ammonia injector. The ammonia injector is arranged with its injection direction facing the adjacent annular ammonia injection pipe, forming a cross-coverage.

[0009] An ammonia gas delivery pipe is provided, and the ammonia gas delivery pipe is connected to multiple annular ammonia injection pipes via delivery branch pipes.

[0010] Through the above technical solution, this utility model provides an annular ammonia injection device suitable for large-scale stoker SCR denitrification systems. By concentrically nesting multiple annular ammonia injection pipes, the contact area between ammonia and flue gas is increased, improving mixing uniformity. The ammonia injectors are arranged towards adjacent annular ammonia injection pipes, forming a cross-coverage of the ammonia injection path, effectively eliminating denitrification blind spots within the flue section, ensuring uniform distribution of ammonia in the flue gas, and improving denitrification efficiency. Staged ammonia supply through ammonia delivery pipe and delivery branch pipes ensures balanced ammonia pressure in each annular pipe, avoiding localized insufficient flow. The modular delivery branch pipe design simplifies pipeline layout and reduces installation complexity. This structure is suitable for large-scale stoker SCR denitrification systems and can meet their high requirements for processing capacity and mixing efficiency.

[0011] Preferably, in the aforementioned annular ammonia injection device suitable for a large-scale stoker SCR denitrification system, each annular ammonia injection pipe is equipped with two sets of ammonia injectors arranged facing the adjacent annular ammonia injection pipes. Each annular pipe has two sets of reverse injectors. By increasing the number and arrangement of the injectors, the contact opportunity between ammonia and flue gas is improved, further expanding the coverage area of ​​a single pipe and reducing localized insufficient ammonia concentration caused by flue gas turbulence. The dual injector sets serve as backups for each other, reducing the risk of decreased denitrification efficiency due to the failure of a single injector.

[0012] Preferably, in the aforementioned annular ammonia injection device suitable for a large-scale stoker SCR denitrification system, the ammonia injectors are inclinedly arranged on the annular ammonia injection pipe. The ammonia injectors on the inner annular ammonia injection pipe are inclined at 40° to the vertical direction, while the ammonia injectors on the remaining annular ammonia injection pipes are inclined at 45° to the vertical direction. The 40° inclined injection on the inner pipe concentrates the coverage of the high-concentration flue gas core area, while the 45° inclined injection on the outer pipe expands the edge diffusion range, achieving stratified gradient mixing of ammonia and flue gas. The angle difference design adapts to the flow velocity distribution within the flue (faster flow velocity at the center and slower flow velocity at the edge), reducing ammonia escape.

[0013] Preferably, in the above-mentioned annular ammonia injection device suitable for a large-scale stoker 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 annular 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 ring-shaped injection port design allows the ammonia to diffuse in an umbrella shape, increasing the contact area with the flue gas; the driven impeller is driven to rotate by the flue gas flow, enhancing the dynamic mixing effect of the ammonia; the detachable design of the nozzle and the connecting shaft facilitates quick replacement or cleaning of clogged injection ports.

[0014] Preferably, in the aforementioned annular ammonia injection device suitable for a large-scale stoker-fired 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. The impeller body and blades convert the kinetic energy of the flue gas into the rotational power of the impeller, forcibly mixing ammonia with the flue gas, thereby increasing the denitrification reaction rate. At the same time, the rotation of the blades can further effectively prevent ash accumulation and clogging of the injection port.

[0015] Preferably, in the aforementioned annular ammonia injection device suitable for a large-scale stoker 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. The threaded connection simplifies the injector maintenance process, allowing disassembly without special tools. The threaded fit can be reinforced with sealant or gaskets to prevent ammonia leakage.

[0016] Preferably, in the aforementioned annular ammonia injection device suitable for a large-scale stoker SCR denitrification system, an electromagnetic flow valve is installed on the ammonia delivery pipe. The electromagnetic flow valve automatically adjusts the ammonia supply based on real-time flue gas parameters (such as NOx concentration and flow rate) to achieve dynamic closed-loop control, reducing ammonia escape; and allocates ammonia flow rate as needed, avoiding resource waste caused by excessive injection.

[0017] Preferably, in the aforementioned annular ammonia injection device suitable for a large-scale stoker SCR denitrification system, the orifice diameter of the ammonia delivery pipe is larger than that of the annular ammonia injection pipe; the orifice diameter of the annular ammonia injection pipe is larger than that of the delivery branch pipe. This decreasing orifice diameter design (main delivery pipe > annular pipe > branch pipe) creates a stable ammonia pressure gradient, ensuring uniform flow at the end injector; the large-diameter main delivery pipe reduces the risk of impurity deposition and extends the system maintenance cycle.

[0018] Preferably, in the above-mentioned annular ammonia injection device suitable for a large-scale stoker SCR denitrification system, the annular ammonia injection pipe is U-shaped. Compared with a circular pipe, the U-shaped annular pipe is easier to match with a square flue, reduces installation gaps, enhances overall rigidity, and the right-angle layout is suitable for flue corner areas, avoiding the waste of space at the corners of a circular pipe.

[0019] As can be seen from the above technical solution, compared with the prior art, this utility model discloses an annular ammonia injection device suitable for large-scale stoker SCR denitrification systems, which has the following beneficial effects:

[0020] 1. This utility model increases the contact area between ammonia and flue gas and improves mixing uniformity by concentrically nesting multiple annular ammonia injection pipes. The ammonia injectors are arranged in the direction of adjacent annular ammonia injection pipes, forming a cross-coverage, effectively eliminating denitrification blind zones in the flue gas cross section and ensuring uniform distribution of ammonia in the flue gas.

[0021] 2. This utility model provides two sets of reverse injectors for each annular pipe. By increasing the number and arrangement of the injectors, the contact opportunities between ammonia and flue gas are improved, further expanding the coverage of a single pipe and reducing the local ammonia concentration deficiency caused by flue gas turbulence.

[0022] 3. Compared with circular pipes, the U-shaped annular pipe of this utility model is easier to match with square flues, reduces installation gaps, enhances overall rigidity, and is suitable for annular ammonia injection devices in large-scale stoker SCR denitrification systems. Attached Figure Description

[0023] 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.

[0024] Figure 1 The attached figure is an isometric view of the annular ammonia injection device for a large-scale stoker SCR denitrification system provided by this utility model;

[0025] Figure 2 The attached figure is a schematic diagram of the ammonia injector provided by this utility model;

[0026] Figure 3 The attached figure is a front view of the annular ammonia injection device for a large-scale stoker SCR denitrification system provided by this utility model;

[0027] Figure 4 The attached figure is a top view of the annular ammonia injection device for a large-scale stoker SCR denitrification system provided by this utility model.

[0028] in:

[0029] 1-Annular ammonia injection pipe; 2-Ammonia injector; 21-Injection pipe; 211-Injection port; 22-Connecting shaft; 23-Driven impeller; 231-Impeller body; 232-Blade; 3-Ammonia delivery pipe; 4-Delivery branch pipe; 5-Solenoid flow valve. Detailed Implementation

[0030] 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.

[0031] See appendix Figure 1 To be continued Figure 4 This utility model discloses an annular ammonia injection device suitable for a large-scale stoker-fired SCR denitrification system, which is installed in the flue gas passage of the large-scale stoker-fired furnace; comprising:

[0032] Multiple annular ammonia injection pipes 1 are arranged concentrically. Each annular ammonia injection pipe 1 is equipped with an ammonia injector 2. The injection direction of the ammonia injector 2 is arranged towards the adjacent annular ammonia injection pipe 1, forming a cross-coverage.

[0033] Ammonia gas delivery pipe 3 is connected to multiple annular ammonia injection pipes 1 via delivery branch pipes 4.

[0034] To further optimize the above technical solution, each annular ammonia injection pipe 1 is equipped with two sets of ammonia injectors 2 arranged facing the adjacent annular ammonia injection pipe 1.

[0035] To further optimize the above technical solution, the ammonia injector 2 is inclined on the annular ammonia injection pipe 1. The ammonia injector 2 on the inner side of the annular ammonia injection pipe 1 is inclined at an angle of 40° with the vertical direction, while the ammonia injector 2 on the other annular ammonia injection pipes 1 is inclined at an angle of 45° with the vertical direction.

[0036] To further optimize the above technical solution, the ammonia injector 2 includes a nozzle 21, a connecting shaft 22, and a driven impeller 23. The bottom end of the nozzle 21 is connected to the annular ammonia injection pipe 1, and the top end face is provided with an annular injection port 211. The bottom end of the connecting shaft 22 is detachably connected to the center of the top end face of the nozzle 21, and the driven impeller 23 rotates at the top end of the connecting shaft 22.

[0037] To further optimize the above technical solution, the driven impeller 23 includes an impeller body 231 rotatably connected to the top of the connecting shaft 22, and a plurality of blades 232 fixed on the impeller body 231.

[0038] To further optimize the above technical solution, the bottom end of the connecting shaft 22 is threadedly connected to the center of the end face of the nozzle 21.

[0039] To further optimize the above technical solution, an electromagnetic flow valve 5 is installed on the ammonia delivery pipe 3.

[0040] To further optimize the above technical solution, the orifice diameter of the ammonia delivery pipe 3 is larger than that of the annular ammonia injection pipe 1; the orifice diameter of the annular ammonia injection pipe 1 is larger than that of the delivery branch pipe 4.

[0041] To further optimize the above technical solution, the annular ammonia injection pipe 1 is U-shaped.

[0042] Large-scale stoker-fired furnaces feature high flue gas flow rates and ample space. Their annular design enables 360° injection, ensuring uniform coverage of the entire cross-section without dead zones and preventing incomplete localized desulfurization. Their continuous injection mode adapts to the dynamic demands of high-flow-rate flue gas, ensuring thorough mixing of ammonia and flue gas.

[0043] 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.

[0044] 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 ring-shaped ammonia injection device suitable for a large-scale stoker-fired SCR denitrification system, characterized in that, include: Multiple annular ammonia injection pipes (1) are arranged concentrically. Each annular ammonia injection pipe (1) is equipped with an ammonia injector (2). The injection direction of the ammonia injector (2) is arranged towards the adjacent annular ammonia injection pipe (1) to form a cross-coverage. Ammonia delivery pipe (3) is connected to multiple annular ammonia injection pipes (1) via delivery branch pipes (4).

2. The annular ammonia injection device for a large-scale stoker SCR denitrification system according to claim 1, characterized in that, Each of the aforementioned annular ammonia injection pipes (1) is equipped with two sets of ammonia injectors (2) arranged respectively facing the adjacent annular ammonia injection pipes (1).

3. The annular ammonia injection device for a large-scale stoker SCR denitrification system according to claim 2, characterized in that, The ammonia injector (2) is arranged obliquely on the annular ammonia injection pipe (1). The ammonia injector (2) on the inner side of the annular ammonia injection pipe (1) is inclined at an angle of 40° with the vertical direction, while the ammonia injector (2) on the remaining annular ammonia injection pipes (1) is inclined at an angle of 45° with the vertical direction.

4. The annular ammonia injection device for a large-scale stoker SCR denitrification system according to claim 1, characterized in that, The ammonia injector (2) includes a nozzle (21), a connecting shaft (22), and a driven impeller (23). The bottom end of the nozzle (21) is connected to the annular ammonia injection pipe (1), and an annular injection port (211) is opened on the end face of the top end. The bottom end of the connecting shaft (22) is detachably connected to the center of the end face of the top end of the nozzle (21), and the driven impeller (23) rotates on the top end of the connecting shaft (22).

5. A ring-shaped ammonia injection device suitable for a large-scale stoker SCR denitrification system according to claim 4, characterized in that, The driven impeller (23) includes an impeller body (231) rotatably connected to the top of the connecting shaft (22) and a plurality of blades (232) fixed on the impeller body (231).

6. A ring-shaped ammonia injection device suitable for a large-scale stoker SCR denitrification system according to claim 4, characterized in that, The bottom end of the connecting shaft (22) is threaded to the center of the end face of the nozzle (21).

7. The annular ammonia injection device for a large-scale stoker SCR denitrification system according to claim 1, characterized in that, An electromagnetic flow valve (5) is installed on the ammonia delivery pipe (3).

8. The annular ammonia injection device for a large-scale stoker SCR denitrification system according to claim 1, characterized in that, The diameter of the ammonia delivery pipe (3) is larger than the diameter of the annular ammonia injection pipe (1); the diameter of the annular ammonia injection pipe (1) is larger than the diameter of the delivery branch pipe (4).

9. A ring-shaped ammonia injection device suitable for a large-scale stoker SCR denitrification system according to claim 8, characterized in that, The annular ammonia spray pipe (1) is square-shaped.

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