Spray gun for back-spraying leachate

Abstract

The invention relates to the field of landfill leachate treatment, and provides a spray gun for leachate back-spraying, which comprises a gun body, a gun head and an atomizing head, the gun head and the atomizing head are mounted on the gun body, and the gun head is used for conveying leachate; the outer wall of the gun head is sleeved with a compressed air pipe, a gap exists between the compressed air pipe and the gun head, a first air channel is formed, and a first one-way valve is arranged in the air channel. A detachable mounting piece is mounted on the side, away from the gun head, of the gun head, the mounting piece is provided with a second air channel communicating with the first air channel, and the second air channel is provided with a second one-way valve; the atomizing head is connected with the outer wall of the compressed air pipe, a gap exists between the atomizing head and the mounting piece, the atomizing head is provided with a plurality of nozzles right opposite to the second air channel, and all the nozzles are arranged around the axis of the atomizing head at intervals. According to the spray gun for back spraying of the leachate, the situation that the leachate flows back to the interior of a compressed air industrial pipeline is reduced.

Description

Technical Field

[0001] The present application relates to the field of landfill leachate treatment, in particular to a spray gun for leachate back-spraying. Background Art

[0002] Landfill leachate has the characteristics of complex composition, high content of heavy metal ions and salt, acidity, and high content of organic matter, which has an impact on the environment and therefore needs to be treated. Currently, landfill leachate is mostly treated by leachate back-spraying. In the leachate back-spraying treatment, the nozzle of the spray gun is injected deep into the incinerator for spraying to incinerate the leachate.

[0003] However, in actual application, it is found that the above conventional solutions have obvious shortcomings, especially under long-term operation conditions, because the nozzle is exposed to extreme working conditions for a long time, which easily leads to nozzle blockage. Once the nozzle is completely blocked by solid particles or other impurities, it will cause untreated liquid to flow back into the compressed air supply pipeline, thereby causing the risk of secondary contamination of the entire system, seriously affecting the normal operation of the equipment and increasing the subsequent maintenance costs. These problems need to be solved urgently. Summary of the invention

[0004] In order to reduce the situation where the leaked liquid flows back into the compressed air industrial pipeline, the present application provides a spray gun for leachate back-spraying.

[0005] The invention provides a spray gun for leachate back-spraying, which adopts the following technical scheme: A spray gun for leachate back-spraying comprises a gun body, a gun head and an atomizing head mounted on the gun body, wherein the gun head is used to transport leachate; a compressed air pipe is sleeved on the outer wall of the gun head, a gap exists between the compressed air pipe and the gun head and a first air channel is formed, and a first one-way valve is arranged in the air channel; a detachable mounting part is mounted on the side of the gun head away from the gun head, the mounting part is provided with a second air channel connected with the first air channel, and the second air channel is provided with a second one-way valve; the atomizing head is connected to the outer wall of the compressed air pipe, and a gap exists between the atomizing head and the mounting part, the atomizing head is provided with a plurality of nozzles arranged opposite to the second air channel, and all the nozzles are arranged at intervals around the axis of the atomizing head.

[0006] By adopting the above technical solution, two sets of one-way valves can be set up to prevent leachate from flowing back into the air channel due to gravity or negative pressure, thereby avoiding contamination of the compressed air system; if a small amount of leachate accidentally breaks through the first one-way valve, the second one-way valve can further block it to avoid contamination of the entire air channel; and the area can be directly exposed by removing the mounting parts, and the residual liquid can be discharged by tilting or flushing to avoid accumulation and blockage. By setting multiple nozzles, the nozzles distributed circumferentially in the atomizing head are set directly opposite to the air channel, ensuring that the compressed air impacts the leachate flow from multiple angles to form finer atomized particles.

[0007] Optionally, a first plug-in block is installed at one end of the mounting member, and a first slot for the first plug-in block to be plugged into is opened at the end of the gun head away from the gun body; the first plug-in block is provided with a first magnetic member, and the first slot is provided with a second magnetic member that cooperates with the first magnetic member.

[0008] By adopting the above-mentioned technical solution, the cooperation between the first plug-in block and the first slot realizes the rapid positioning and connection of the mounting part and the gun head, and the interaction between the first magnetic part and the second magnetic part further enhances the stability of the connection, effectively preventing loosening due to high temperature or vibration, and at the same time simplifies the assembly process and improves maintenance efficiency.

[0009] Optionally, the atomizing head is rotatably connected to the compressed air pipe through a rotating assembly, and a plurality of scrapers are provided on the side of the atomizing head close to the mounting member, and one side of the scraper is abutted against the end of the mounting member away from the gun head; the scraper is located between two adjacent nozzles, and the scraper is inclined at the end away from the mounting member.

[0010] By adopting the above technical solution, when the atomizer head is rotatably connected to the compressed air pipe through the rotating assembly, and a plurality of scrapers abutting against the mounting member are provided on the side of the atomizer head close to the mounting member, this design applies force to the scrapers when the compressed air is ejected through the nozzle, so that the atomizer head rotates. As the atomizer head rotates, the scrapers will continuously contact the mounting member and produce slight friction. This friction helps to remove the leachate residues that may accumulate on or near the surface of the mounting member, preventing them from having a negative impact on the atomization effect.

[0011] Optionally, the scraper side wall is provided with a plurality of crushing blocks.

[0012] By adopting the above technical solution, the crushing block breaks up the bulk material, and the crushing block ensures that the leachate is in a smaller and more uniform state before atomization. This helps the compressed air and leachate to mix more fully, thereby producing a more delicate atomization effect.

[0013] Optionally, a fixed plate and a sliding plate are provided in the first air channel, the fixed plate is provided on a side of the sliding plate away from the gun body; the fixed plate is provided with a first through hole, and the sliding plate is provided with a second through hole; the compressed air pipe is provided with a sliding groove, the sliding groove is extended around the outer circumference of the compressed air pipe, and the distance from the sliding groove to the fixed plate gradually increases along the axial direction of the gun head; an extension rod is fixed to the outer layer of the sliding plate, the extension rod is passed through the sliding groove and movably arranged inside the sliding groove; The rotating assembly is provided with a guide block, the guide block is used to abut against the extension rod, and the guide block is used to guide the extension rod to move toward a side away from the fixed plate; the gun head is provided with a torsion spring, the two ends of the torsion spring are respectively connected to the gun head and the rotating assembly, and the elastic force of the torsion spring is used to drive the guide block to move toward a side away from the extension rod; When there is compressed air in the first air channel, the compressed air forces the sliding plate to press against the fixed plate, and the first through hole and the second through hole are arranged opposite each other; when the guide block is connected to the extension rod and guides the extension rod to move toward the side away from the fixed plate, the first through hole and the second through hole are arranged in an offset manner.

[0014] By adopting the above technical solution, when the first air channel is filled with compressed air, the compressed air will generate a certain pressure, forcing the sliding plate to be tightly attached to the fixed plate. At this time, the first through hole and the second through hole are completely aligned, allowing the compressed air and leachate to mix and be sprayed out through the nozzle.

[0015] At the same time, as the spray head rotates, the guide block will contact the extension rod and guide it to move away from the fixed plate. In this process, the first through hole and the second through hole will gradually misalign, resulting in a decrease in the pressure of the compressed air. When this pressure decreases to a certain extent, the elastic force of the torsion spring will play a role, driving the guide block to return to its original state and driving the spray head to rotate in the opposite direction. This process will be repeated continuously, so that the atomizing head can rotate back and forth.

[0016] This back-and-forth rotation of the atomizer head brings multiple advantages. First, it can change the position and angle of the nozzle so that the atomized droplets can be more evenly distributed in the target area, thereby improving the uniformity and coverage of the atomization. Secondly, the back-and-forth rotation also helps to reduce the retention of impurities between the atomizer head and the mounting, keeping the nozzle clean and unobstructed, thereby ensuring the atomization effect. Finally, this design also effectively reduces the backflow of leachate into the air channel, improving the stability and reliability of the entire spray gun system.

[0017] Optionally, the rotating assembly includes a fixed ring fixed to the gun head and a rotating ring rotatably connected to the fixed ring, the guide block and the torsion spring are both connected to the rotating ring, and the atomizing head is detachably connected to the rotating ring; the gun head cover is provided with a cover, and the sliding groove cover is arranged inside the cover.

[0018] By adopting the above technical solution, the detachable connection between the atomizer head and the rotating ring increases the convenience of use and facilitates the replacement or maintenance of the atomizer head; the cover provided on the gun head not only protects the internal mechanical structure from damage by the external environment, but also can maintain the pressure of the compressed air.

[0019] Optionally, the atomizer head is equipped with a mounting block, and the rotating ring is provided with a mounting groove for the mounting block to be plugged in; the side wall of the mounting block is provided with a first fixed groove, a fixed block is movably installed in the first fixed groove, and the mounting groove is provided with a second fixed groove for the fixed block to be plugged in; a spring is provided between the fixed block and the first fixed groove, and the elastic force of the spring is used to drive the fixed block to be normally plugged into the second fixed groove.

[0020] By adopting the above technical solution, the matching design of the fixing block and the second fixing groove ensures the stability of the atomizer head during the rotation process; even in the case of high-pressure or high-speed spraying, the atomizer head can maintain a firm connection and is not easy to fall off or loosen. The elastic force of the spring continuously acts on the fixing block, making it fit tightly in the second fixing groove, thereby enhancing the stability of the connection.

[0021] Optionally, a plurality of balls are rotatably mounted on the inner wall of the atomizing head, and the balls are in contact with the outer wall of the gun head.

[0022] By adopting the above technical solution, a plurality of balls are rotatably mounted on the inner wall of the atomizing head, and the balls are in contact with the outer wall of the gun head, which can significantly reduce the friction resistance when the atomizing head rotates relative to the gun head, and improve the smoothness of the rotation process. At the same time, this structural design helps to extend the service life of components, reduce wear problems caused by frequent use, and ensure the stable performance of the spray gun under long-term operation.

[0023] In summary, the present application includes at least one of the following beneficial technical effects: 1. By setting the first one-way valve and the second one-way valve, it is possible to prevent leachate from flowing back into the air channel due to gravity or negative pressure, thereby avoiding contamination of the compressed air system; if a small amount of leachate accidentally breaks through the first one-way valve, the second one-way valve can further block it to avoid contamination of the entire air channel; and the area can be directly exposed by removing the mounting parts, and the residual liquid can be discharged by tilting or flushing to avoid blockage caused by accumulation; 2. By driving the atomizing head to rotate back and forth at the end of the gun head, the debris can be repeatedly crushed by the crushing blocks on the side where the two scrapers are close to each other, reducing the situation where the debris abuts against one side of the scraper due to centrifugal force under normal conditions, avoiding the accumulation or blockage of debris near the nozzle, thereby ensuring that the spray gun can work continuously and stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic structural diagram of Example 1; Figure 2 is a partial cross-sectional view of Example 1; Figure 3 yes Figure 2 A local enlarged view of point a; Figure 4 yes Figure 2 A local enlarged view of point b; Figure 5 is a partial cross-sectional view of Example 2; Figure 6 yes Figure 5 A local enlarged view of point c; Figure 7 This is a partial cross-sectional view of the cover of Example 2.

[0025] Explanation of the accompanying drawings: 1. gun body; 2. gun head; 21. first slot; 3. compressed air pipe; 31. first air channel; 32. second slot; 33. sliding slot; 34. cover; 35. first one-way valve; 4. mounting member; 41. first sleeve; 42. second sleeve; 43. second air channel; 44. first plug-in block; 45. second plug-in block; 46. second one-way valve; 5. atomizing head; 51. nozzle; 52. scraper; 53. crushing block; 54. mounting block; 55. first fixed slot; 56. spring; 57. fixed block; 58. hemispherical head; 6. rotating assembly; 61. fixing ring; 62. rotating ring; 63. mounting slot; 64. second fixed slot; 65. guide block; 66. guide surface; 67. torsion spring; 7. fixing plate; 71. first through hole; 8. sliding plate; 81. extension rod; 82. second through hole. DETAILED DESCRIPTION

[0026] The following is combined with Figure 1-Figure 7 This application is described in further detail.

[0027] Example 1 The embodiment of the present application discloses a spray gun for leachate back-spraying.

[0028] Reference Figure 1 and Figure 2A spray gun for leachate back-spraying includes a gun body 1, a gun head 2, a compressed air pipe 3, a mounting part 4 and an atomizing head 5. The gun head 2 is connected to the gun body 1 and is used to inject leachate into the gun head 2; wherein the compressed air pipe 3 is sleeved on the outer wall of the gun head 2, and a first air channel 31 is formed between the gun head 2 and the compressed air pipe 3. A first one-way valve 35 is installed in the first air channel 31, which only allows compressed air to flow from a specific direction to prevent the leachate from flowing back.

[0029] Reference Figure 2 The mounting member 4 includes a first sleeve 41 and a second sleeve 42, the length of the first sleeve 41 is smaller than that of the second sleeve 42; the first sleeve 41 is inserted into the second sleeve 42, and there is a gap between the first sleeve 41 and the second sleeve 42 to form a second air channel 43, and the second air channel 43 is used to communicate with the first air channel 31; a second one-way valve 46 is arranged in the second air channel 43, and the first one-way valve 35 and the second one-way valve 46 have the same functions and are both prior arts, which will not be elaborated here.

[0030] Reference Figure 3 A first plug-in block 44 is provided on one side of the first sleeve 41, and the gun head 2 is provided with a first slot 21 for the first plug-in block 44 to be plugged in; the first plug-in block 44 is provided with a first magnetic attraction component, and the first slot 21 is provided with a second magnetic attraction component, and the first magnetic attraction component and the second magnetic attraction component are magnetically matched.

[0031] Reference Figure 2 In this embodiment, the second sleeve 42 is provided with a second plug-in block 45, and the air passage is provided with a second slot 32 for the second plug-in block 45 to be plugged in; since the second plug-in block 45 has the same structure as the first plug-in block 44, they will not be described in detail here.

[0032] The fast positioning and connection of the mounting member 4 and the gun head 2 can be achieved through the plug-in cooperation between the plug-in block and the plug-in slot, thereby increasing the stability of the connection, simplifying the assembly process, and improving the maintenance efficiency.

[0033] Reference Figure 2 The atomizing head 5 is sleeved on the mounting member 4 and connected to the compressed air pipe 3 through the rotating assembly 6. The atomizing head 5 abuts against the end of the second sleeve 42 away from the compressed air pipe 3, and there is a gap between the atomizing head 5 and the first sleeve 41; the atomizing head 5 is provided with a plurality of nozzles 51, and all the nozzles 51 are arranged at intervals around the axis of the atomizing head 5; when the spray gun is used, the leachate passes through the gap between the atomizing head 5 and the first sleeve 41, and at this time, the compressed air sprays the leachate from the nozzle 51 in the form of mist particles through the second channel.

[0034] A plurality of scrapers 52 are arranged on the inner wall of one side of the atomizing head 5 close to the first sleeve 41, and each scraper 52 is respectively installed between two adjacent nozzles 51, and one end of the first scraper 52 away from the nozzle 51 is arranged obliquely and abuts against the first sleeve 41. When the compressed air is ejected through the nozzle 51, force is applied to the scraper 52 to rotate the atomizing head 5. As the atomizing head 5 rotates, the scraper 52 will continuously contact the first sleeve 41 and produce slight friction, which helps to remove the leachate residues that may be accumulated on or near the surface of the mounting member 4, and prevent them from having a negative impact on the atomization effect.

[0035] The side wall of the scraper 52 is provided with a plurality of crushing blocks 53, which can crush larger particles during rotation to reduce the risk of clogging. The crushing blocks 53 are made of hard alloy or ceramic materials, which have good strength and wear resistance and can effectively cope with the impact of various solid impurities.

[0036] A plurality of balls (not shown in the figure) are installed on the inner wall of the atomizing head 5, and one side of the balls is in contact with the outer wall of the gun head 2. The balls are used to reduce the friction resistance between the atomizing head 5 and the compressed air pipe 3, improve the smoothness of the rotation process, and reduce the wear problem caused by frequent use, thereby ensuring the stable performance of the spray gun under long-term operation.

[0037] Reference Figure 2 and Figure 4 The rotating assembly 6 includes a fixed ring 61 and a rotating ring 62, the fixed ring 61 is fixedly connected to the gun head 2, and the rotating ring 62 is rotatably connected thereto; a mounting block 54 is provided on one side of the atomizing head 5, and the rotating ring 62 is provided with a mounting groove 63 for the mounting block 54 to be plugged in; a first fixed groove 55 is provided on the outer wall of the mounting block 54, and a fixed block 57 is movably installed in the first fixed groove 55, and a second fixed groove 64 for the fixing block 57 to be plugged in is provided on the mounting block 54 away from the mounting groove 63, and one end of the second fixed groove 64 away from the mounting groove 63 is connected to the outside.

[0038] A hemispherical head 58 is provided at one end of the fixing block 57 away from the first fixing groove 55, and the hemispherical head 58 is used to allow the fixing block 57 to completely enter the first fixing groove 55; a spring 56 is provided between the fixing block 57 and the first fixing groove 55, and the elastic force of the spring 56 is used to drive the fixing block 57 to penetrate the second fixing groove 64 to penetrate the outside world. The matching design of the fixing block 57 and the second fixing groove 64 ensures the stability of the atomizing head 5 during the rotation process, and the atomizing head 5 can be disassembled and replaced, so as to remove and clean the mounting member 4 between the atomizing head 5 and the gun head 2, and maintain the atomization effect of the spray gun.

[0039] The implementation principle of Example 1 of the present application is: By providing two sets of one-way valves, it is possible to prevent leachate from flowing back into the air passage due to gravity or negative pressure, thereby avoiding contamination of the compressed air system. If a small amount of leachate accidentally breaks through the first one-way valve 35, the second one-way valve 46 can further block it to avoid contamination of the entire air passage. The area can be directly exposed by removing the mounting member 4, and the residual liquid can be discharged by tilting or flushing to avoid blockage caused by accumulation.

[0040] The nozzle 51 is arranged directly opposite to the second air channel 43, so that the compressed air can directly act on the nozzle 51 area. This design ensures that the air flow can effectively flush the nozzle 51, prevent impurities in the leachate from accumulating at the nozzle 51, reduce the risk of blockage, and further reduce the possibility of leakage liquid flowing back into the compressed air industrial pipeline.

[0041] Example 2 The embodiment of the present application discloses a spray gun for leachate back-spraying.

[0042] Reference Figure 5 and Figure 6 The difference between Example 2 of the present application and Example 1 is that: a fixed plate 7 and a sliding plate 8 are arranged in the first air channel 31, the fixed plate 7 is fixed to the first air channel 31, and the sliding plate 8 is slidably installed in the first air channel 31 and is located on the side of the fixed plate 7 away from the atomizing head 5; the fixed plate 7 is provided with a plurality of through first through holes 71, and all the first through holes 71 are arranged equidistantly around the central axis of the fixed plate 7; the sliding plate 8 is provided with a plurality of through second through holes 82, and all the second through holes 82 are arranged equidistantly around the central axis of the sliding plate 8.

[0043] Reference Figure 7 A sliding groove 33 connected to the first air channel 31 is provided on the outer wall of the compressed air pipe 3. The sliding groove 33 is arranged around the outer wall of the compressed air pipe 3, and the distance between the sliding groove 33 and the fixed plate 7 gradually increases along the axial direction of the compressed air pipe 3; an extension rod 81 is fixed to the outside of the sliding plate 8, and the extension rod 81 is inserted into the sliding groove 33 and can slide freely in the sliding groove 33.

[0044] Reference Figure 7 A guide block 65 is fixed to the rotating ring 62, and the length of the guide block 65 is the same as the distance from the rotating ring 62 to the end of the sliding groove 33 away from the rotating ring 62; one side of the fixed block 57 is set as a guide surface 66, and the other side of the fixed block 57 is set as a reference surface, and the distance between the guide surface 66 and the reference surface gradually decreases from the side close to the rotating ring 62 to the side away from the rotating ring 62; the guide surface 66 is used to abut against the extension rod 81, and is used to guide the extension rod 81 to move toward the side away from the rotating ring 62.

[0045] A torsion spring 67 is sleeved on the outer wall of the compressed air pipe 3, and a positioning portion is integrally formed on the outer wall of the compressed air pipe 3. One end of the torsion spring 67 is connected to the positioning portion, and the other end of the torsion spring 67 is fixed to the rotating ring 62. The elastic force of the torsion spring 67 is used to guide the fixed block 57 to rotate toward the side away from the extension rod 81.

[0046] A cover 34 is provided on the outer wall of the gun head 2, the sliding groove 33 is covered inside the cover 34, and one side of the cover 34 is in contact with the rotating ring 62; the cover 34 not only protects the internal mechanical structure from damage by the external environment, but also can maintain the pressure of the compressed air.

[0047] When there is compressed air in the first air channel 31, the compressed air forces the sliding plate 8 to abut against the fixed plate 7, and at this time the first through hole 71 and the second through hole 82 are arranged opposite to each other; when the guide block 65 abuts against the extension rod 81 and guides the extension rod 81 to move toward the side away from the fixed plate 7, the first through hole 71 and the second through hole 82 are arranged in an offset manner.

[0048] The implementation principle of Example 2 of the present application is: When the first air channel 31 is filled with compressed air, the compressed air will generate a certain pressure, forcing the sliding plate 8 to be tightly attached to the fixed plate 7. At this time, the first through hole 71 and the second through hole 82 are completely aligned, allowing the compressed air and the leachate to mix and be ejected through the nozzle 51.

[0049] At the same time, as the spray head rotates, the guide block 65 will contact the extension rod 81 and guide it to move away from the fixed plate 7. In this process, the first through hole 71 and the second through hole 82 will gradually misalign, resulting in a decrease in the pressure of the compressed air. When the pressure decreases to a certain extent, the elastic force of the torsion spring 67 will play a role, driving the guide block 65 to return to its original state, while driving the spray head to rotate in the opposite direction. This process will be repeated continuously, so that the atomizing head 5 can rotate back and forth.

[0050] During the back-and-forth rotation of the atomizing head 5, the crushing blocks 53 can be crushed into smaller particles before the debris is thrown toward the scraper 52, thereby greatly reducing the possibility of their normal contact with the scraper 52, reducing the situation where the debris normally abuts against one side of the scraper 52 due to centrifugal force, and avoiding the accumulation or blockage of debris near the nozzle 51, thereby ensuring that the spray gun can work continuously and stably.

[0051] The above are preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A spray gun for leachate back-spraying, characterized in that: The invention comprises a gun body (1), a gun head (2) and an atomizing head (5) mounted on the gun body (1), wherein the gun head (2) is used to transport leachate; a compressed air pipe (3) is sleeved on the outer wall of the gun head (2), a gap exists between the compressed air pipe (3) and the gun head (2) and a first air channel (31) is formed, and a first non-return valve (35) is arranged in the air channel; a detachable mounting member (4) is mounted on the side of the gun head (2) away from the gun head (2), the mounting member (4) is provided with a second air channel (43) connected to the first air channel (31), and the second air channel (43) is provided with a second non-return valve (46); the atomizing head (5) is connected to the outer wall of the compressed air pipe (3), and a gap exists between the atomizing head (5) and the mounting member (4); the atomizing head (5) is provided with a plurality of nozzles (51) arranged opposite to the second air channel (43), and all the nozzles (51) are arranged at intervals around the axis of the atomizing head (5).

2. A spray gun for leachate back-spraying according to claim 1, characterized in that: A first plug-in block (44) is mounted on one end of the mounting member (4), and a first slot (21) for plugging the first plug-in block (44) is provided at one end of the gun head (2) away from the gun body (1); the first plug-in block (44) is provided with a first magnetic attraction member, and the first slot (21) is provided with a second magnetic attraction member that matches the first magnetic attraction member.

3. A spray gun for leachate back-spraying according to claim 1, characterized in that: The atomizing head (5) is rotatably connected to the compressed air pipe (3) via a rotating assembly (6); a plurality of scrapers (52) are provided on a side of the atomizing head (5) close to the mounting member (4); one side of the scraper (52) abuts against an end of the mounting member (4) away from the gun head (2); the scraper (52) is located between two adjacent nozzles (51), and an end of the scraper (52) away from the mounting member (4) is inclined.

4. A spray gun for leachate back-spraying according to claim 3, characterized in that: A plurality of crushing blocks (53) are provided on the side wall of the scraper (52).

5. A spray gun for leachate back-spraying according to claim 3, characterized in that: A fixed plate (7) and a sliding plate (8) are provided in the first air passage (31), wherein the fixed plate (7) is provided on a side of the sliding plate (8) away from the gun body (1); the fixed plate (7) is provided with a first through hole (71), and the sliding plate (8) is provided with a second through hole (82); the compressed air pipe (3) is provided with a sliding groove (33), wherein the sliding groove (33) extends around the outer circumference of the compressed air pipe (3), and the distance between the sliding groove (33) and the fixed plate (7) gradually increases along the axial direction of the gun head (2); an extension rod (81) is fixed to the outer layer of the sliding plate (8), wherein the extension rod (81) passes through the sliding groove (33) and is movably arranged inside the sliding groove (33); The rotating assembly (6) is provided with a guide block (65), the guide block (65) being used to abut against the extension rod (81), and the guide block (65) being used to guide the extension rod (81) to move toward a side away from the fixed plate (7); the gun head (2) is provided with a torsion spring (67), the two ends of the torsion spring (67) being respectively connected to the gun head (2) and the rotating assembly (6), and the elastic force of the torsion spring (67) is used to drive the guide block (65) to move toward a side away from the extension rod (81); When compressed air is present in the first air passage (31), the compressed air forces the sliding plate (8) to abut against the fixed plate (7), and at this time the first through hole (71) and the second through hole (82) are arranged opposite each other; when the guide block (65) is connected to the extension rod (81) and guides the extension rod (81) to move toward a side away from the fixed plate (7), the first through hole (71) and the second through hole (82) are arranged in an offset manner.

6. A spray gun for leachate back-spraying according to claim 5, characterized in that: The rotating assembly (6) comprises a fixed ring (61) fixed to the gun head (2) and a rotating ring (62) rotatably connected to the fixed ring (61); the guide block (65) and the torsion spring (67) are both connected to the rotating ring (62); the atomizing head (5) is detachably connected to the rotating ring (62); the gun head (2) is provided with a cover (34); and the sliding groove (33) is covered inside the cover (34).

7. A spray gun for leachate back-spraying according to claim 6, characterized in that; The atomizing head (5) is provided with a mounting block (54); the rotating ring (62) is provided with a mounting groove (63) for the mounting block (54) to be plugged in; a side wall of the mounting block (54) is provided with a first fixing groove (55), a fixing block (57) is movably installed in the first fixing groove (55), and the mounting groove (63) is provided with a second fixing groove (64) for the fixing block (57) to be plugged in; a spring (56) is provided between the fixing block (57) and the first fixing groove (55), and the elastic force of the spring (56) is used to drive the fixing block (57) to be plugged in the second fixing groove (64) under normal conditions.

8. The spray gun for leachate back-spraying according to claim 6, characterized in that: A plurality of balls are rotatably mounted on the inner wall of the atomizing head (5), and the balls are in contact with the outer wall of the gun head (2).

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