Black liquor spray gun for large alkali recovery boiler

Abstract

The utility model relates to a black liquor spray gun for a large alkali recovery boiler, and belongs to the technical field of combustion devices of alkali recovery boilers. One end of the special-shaped connector is communicated with the side wall of the spray gun nozzle, and the other end of the special-shaped connector is communicated with the flow guide pipe; the upper end of the spray gun nozzle is sealed, the lower end of the spray gun nozzle is provided with a black liquor nozzle, and the top of the spray gun nozzle is flush with the special-shaped connector and arranged in an offset mode for guiding black liquor to tangentially flow into the spray gun nozzle. The connecting structure of the conventional black liquor spray gun is changed, the cyclone effect of the black liquor is improved, the flowing dead angle of the black liquor is avoided, and the black liquor is sprayed more uniformly.

Description

Technical Field

[0001] This utility model relates to a black liquor spray gun for a large alkali recovery boiler, belonging to the technical field of combustion devices for alkali recovery boilers. Background Technology

[0002] With the rapid development of the paper industry, alkali recovery technology, as an effective means of treating black liquor in papermaking, has been widely used in the pulp and paper sector. Alkali recovery boilers use black liquor as fuel, injecting it into the furnace through black liquor spray guns for combustion. This process oxidizes the organic matter in the black liquor while simultaneously recovering inorganic substances, which is of great significance for reducing environmental pollution and lowering production costs.

[0003] Patent document CN202321629150.X discloses a black liquor spray gun for a soda ash furnace with strong swirling side-jet capability. This spray gun, by incorporating a swirling generator, causes the black liquor to generate a strong swirling flow within a columnar cavity and move downwards, ultimately being sprayed horizontally in a fan shape from the notch. This design endows the black liquor droplets with both horizontal and rotational kinetic energy, extending their descent trajectory and time, which is beneficial for thorough drying and combustion. However, this technical solution suffers from certain dead zones in the black liquor flow within the gun barrel, and thermal stress concentration under high-temperature conditions can affect the service life of the spray gun. To address these issues, this utility model aims to provide a novel black liquor spray gun. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the shortcomings of the existing technology and provide a black liquor spray gun for a large alkali recovery boiler, optimize the connection structure of the spray gun, improve the swirling effect of the black liquor, avoid dead corners in the flow of black liquor, and make the black liquor spraying more uniform.

[0005] The black liquor spray gun for a large alkali recovery boiler described in this utility model includes a spray gun nozzle, a shaped connector, and a guide pipe. One end of the shaped connector is connected to the side wall of the spray gun nozzle, and the other end of the shaped connector is connected to the guide pipe. The upper end of the spray gun nozzle is sealed, and the lower end is provided with a black liquor nozzle. The top of the inner side of the spray gun nozzle is flush with the top of the inner side of the shaped connector. The shaped connector is offset on the outer periphery of the spray gun nozzle to guide the black liquor tangentially into the spray gun nozzle.

[0006] Preferably, the irregular joint is welded from a left side plate and a right side plate. The welding bevels of the irregular joint are all located on one side of the outer wall of the irregular joint, which can not only ensure the strength of the weld, but also ensure that the inner wall of the irregular joint is smooth and improve the fluidity of the black liquor.

[0007] Preferably, the left and right side plates are arc-shaped to enhance the swirling effect of the black liquor.

[0008] Preferably, the right side plate is shorter than the left side plate. The left side plate is positioned tangent to the outer periphery of the spray gun nozzle, and the right side plate is positioned intersecting the outer periphery of the spray gun nozzle. The left and right side plates together form a tubular irregular joint. The outlet of the irregular joint near the spray gun nozzle is elliptical. The inlet of the irregular joint near the guide tube is adapted to the shape of the guide tube. The major axis of the ellipse is equal to the height between the upper and lower ends of the spray gun nozzle, and the minor axis of the ellipse is smaller than the diameter of the guide tube. The flow cross-sectional area of ​​the outlet of the irregular joint is smaller than that of the guide tube.

[0009] Preferably, the black liquor nozzle is a conical nozzle, which makes the black liquor spray more uniform. The upper diameter of the conical nozzle is smaller than that of the lower diameter, and the upper diameter faces into the nozzle head of the spray gun.

[0010] Preferably, the end of the guide tube is provided with a threaded joint to facilitate the disassembly and assembly of the black liquor spray gun.

[0011] Compared with the prior art, the beneficial effects of this utility model are:

[0012] 1. This utility model avoids the problem of black liquor accumulation and coking caused by the flush arrangement of the top inner side of the spray gun nozzle with the top inner side of the irregular joint, alleviates the thermal stress concentration at the connection part under high temperature environment, and extends the service life of the spray gun.

[0013] 2. The welding bevels of the irregular joints are all opened on one side of the outer wall of the irregular joint, which not only ensures the strength of the weld, but also ensures the smoothness of the internal surface, reduces the resistance of the black liquor during the flow process, and improves the fluidity of the black liquor.

[0014] 3. The spray gun nozzle and the irregular joint are offset, allowing the black liquor to flow tangentially into the spray gun nozzle. The left and right side plates of the irregular joint are designed with a certain arc shape, which allows the black liquor to form a vortex before entering the spray gun nozzle, making the black liquor particles smaller and more uniform when sprayed, thereby improving the combustion efficiency.

[0015] 4. The conical black liquor nozzle allows for a wider and more uniform black liquor spray range, which is beneficial for the complete combustion of black liquor in the furnace. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of one embodiment of the present invention;

[0017] Figure 2 yes Figure 1 Schematic diagram of offset connection between the spray gun nozzle and the irregularly shaped connector;

[0018] Figure 3 yes Figure 1 Schematic diagram of the structure of the irregular joint component;

[0019] Figure 4 yes Figure 1Schematic diagram of the welding structure of the irregular joint.

[0020] In the diagram: 1. Spray gun nozzle; 2. Irregular connector; 3. Guide tube; 4. Threaded connector;

[0021] 11. Black liquor nozzle. Detailed Implementation

[0022] Example 1

[0023] like Figures 1-4 As shown, the large-scale black liquor spray gun for alkali recovery boilers of this utility model includes a spray gun nozzle 1, a special-shaped connector 2, and a guide pipe 3. One end of the special-shaped connector 2 is connected to the side wall of the spray gun nozzle 1, and the other end of the special-shaped connector 2 is connected to the guide pipe 3. The end of the guide pipe 3 is provided with a threaded connector 4 for convenient disassembly and assembly of the black liquor spray gun.

[0024] The upper end of the spray gun nozzle 1 is sealed, and the lower end is provided with a conical black liquid nozzle 11. The top of the inner side of the spray gun nozzle 1 is flush with the top of the inner side of the irregular connector 2. The irregular connector 2 is offset on the side wall of the spray gun nozzle 1 to guide the black liquid tangentially into the spray gun nozzle 1. The irregular joint 2 is welded from a left side plate and a right side plate. The left and right side plates are arc-shaped to enhance the swirling effect of the black liquor. The right side plate is shorter than the left side plate. The left side plate is positioned tangent to the outer periphery of the spray gun nozzle 1, and the right side plate is positioned intersecting the outer periphery of the spray gun nozzle 1. The left and right side plates are joined together to form a tubular irregular joint 2. The outlet of the irregular joint 2 near the spray gun nozzle 1 is elliptical. The inlet of the irregular joint 2 near the guide tube 3 is adapted to the shape of the guide tube 3. The major axis of the ellipse is equal to the height between the upper and lower ends of the spray gun nozzle 1, and the minor axis of the ellipse is smaller than the diameter of the guide tube 3. This is used to reduce the flow cross-sectional area of ​​the outlet of the irregular joint 2 to be smaller than that of the guide tube 3, thereby increasing the flow velocity of the black liquor sprayed from the outlet of the irregular joint and ensuring that the black liquor sprayed from the irregular joint covers the inner periphery of the spray gun nozzle 1, avoiding uneven heating and thus preventing the spray gun nozzle 1 from burning out. The welding bevel at the connection between the irregular joint 2 and the guide pipe 3 or the spray gun nozzle 1 is located on one side of the outer wall of the irregular joint 2. The black liquor nozzle 11 is a conical nozzle with a nozzle diameter smaller than the inner diameter of the spray gun nozzle 1. It is used to increase the spray rate at the nozzle. The upper diameter of the conical nozzle is smaller than the lower diameter, and the upper end faces the inside of the spray gun nozzle 1, so that the black liquor forms a conical liquid curtain after being sprayed out, which can reduce the black liquor particles carried in the air and reduce coking at the tail of the alkali furnace.

[0025] Working process or working principle:

[0026] The black liquor spray gun is connected to the black liquor inlet pipe via a threaded connector 4. The black liquor flows from the guide pipe 3 through the shaped connector 2. Because the left and right side plates of the shaped connector are arc-shaped, the black liquor forms a swirling flow before entering the spray gun nozzle 1. Subsequently, the black liquor flows tangentially into the spray gun nozzle 1, further enhancing the swirling effect. Finally, the black liquor is evenly sprayed out through the conical black liquor nozzle 11, and is uniformly dispersed within the alkali recovery boiler, achieving efficient combustion.

[0027] The descriptions of the orientation and relative positional relationships of the structure in this utility model, such as descriptions of front, back, left, right, up, and down, do not constitute a limitation on this utility model, but are merely for the convenience of description.

Claims

1. A black liquor spray gun for a large-scale alkali recovery boiler, characterized in that, It includes a spray gun nozzle (1), a special-shaped connector (2) and a guide tube (3). One end of the special-shaped connector (2) is connected to the side wall of the spray gun nozzle (1), and the other end of the special-shaped connector (2) is connected to the guide tube (3). The upper end of the spray gun nozzle (1) is sealed, and the lower end is provided with a black liquid nozzle (11). The top of the inner side of the spray gun nozzle (1) is flush with the top of the inner side of the irregular connector (2). The irregular connector (2) is offset on the outer periphery of the spray gun nozzle (1) to guide the black liquid tangentially into the spray gun nozzle (1).

2. The black liquor spray gun for a large-scale alkali recovery boiler according to claim 1, characterized in that, The irregular joint (2) is welded from the left side plate and the right side plate. The welding bevel of the irregular joint (2) is located on one side of the outer wall of the irregular joint (2).

3. The black liquor spray gun for a large-scale alkali recovery boiler according to claim 2, characterized in that, The left and right side panels are arc-shaped.

4. The black liquor spray gun for a large-scale alkali recovery boiler according to claim 3, characterized in that, The right side plate is shorter than the left side plate. The left side plate is set to be tangent to the outer periphery of the spray gun nozzle (1). The right side plate is set to intersect with the outer periphery of the spray gun nozzle (1). The left side plate and the right side plate are combined to form a tubular irregular joint (2). The outlet of the irregular joint (2) near the spray gun nozzle (1) is elliptical. The inlet of the irregular joint (2) near the guide tube (3) is adapted to the shape of the guide tube (3). The major axis of the ellipse is equal to the height between the upper and lower ends of the spray gun nozzle (1). The minor axis of the ellipse is smaller than the diameter of the guide tube (3). The flow cross-sectional area of ​​the outlet of the irregular joint (2) is smaller than that of the guide tube (3).

5. The black liquor spray gun for a large-scale alkali recovery boiler according to claim 1, characterized in that, The black liquor nozzle (11) is a conical nozzle. The upper diameter of the conical nozzle is smaller than that of the lower diameter, and the upper diameter faces the inside of the spray gun nozzle (1).

6. The black liquor spray gun for a large-scale alkali recovery boiler according to claim 1, characterized in that, The end of the guide tube (3) is provided with a threaded joint (4).

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