A supersonic flame spraying device and spraying method for the inner wall of a spiral case draft chamber

Abstract

This invention discloses a supersonic flame thermal spraying device and method for the inner wall of a spiral-shaped water inlet chamber. The device includes a continuously rotating supersonic flame spray gun, a servo motor, an industrial robot, and a movable platform. The movable platform includes a movable platform body and supporting components. The industrial robot is mounted on the platform body. The platform body and supporting components cooperate to allow the movable platform to move stably around the inner wall of the spiral-shaped water inlet chamber during the spraying process. The continuously rotating supersonic flame spray gun is connected to the end of the industrial robot and can rotate continuously in the same direction without being restricted by the spray gun pipeline. This invention can replace the manual supersonic flame spraying work for the surface of large spiral-shaped water inlet chambers in actual engineering applications, solving the problem of pipeline entanglement and twisting during continuous rotation spraying due to the limitations of the supersonic flame spray gun pipeline; and greatly improving the efficiency of engineering implementation and enhancing the uniformity of the coating.

Description

Technical Field

[0001] This invention belongs to the field of water conservancy equipment protection, and particularly relates to a supersonic flame thermal spraying device and spraying method for the inner wall of a spiral casing water intake chamber. Background Technology

[0002] Currently, the spiral casings of large-scale hydroelectric power generation equipment with medium to high heads (such as large water turbines) are mostly made of metal with a circular cross-section, which effectively reduces the loss of kinetic energy. The spiral casings are mostly embedded in reinforced concrete and fixed, so they will not move during their service life. Therefore, during service, the coating preparation of the inner wall of the spiral casing is carried out inside the casing. Currently, the main engineering solution is for personnel to enter the spiral casing and manually spray with a handheld spray gun. This method produces coatings with poor uniformity, resulting in some areas exceeding the standard coating thickness while others do not, leading to material waste and coating quality problems. Furthermore, manual spraying makes it difficult to precisely control the distance between the spray gun and the workpiece, making coating quality control difficult. In addition, this construction method is inefficient, requires workers to rest, and prolonged spraying inside the spiral casing poses health risks. Therefore, there is an urgent need in practical engineering applications for a highly efficient, uniform, and automated thermal spraying device and method. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a method and apparatus for supersonic flame thermal spraying of the inner wall of the spiral casing of large water turbines and other equipment.

[0004] The technical solution provided by the present invention to solve the above problems is as follows:

[0005] A supersonic flame thermal spraying device for the inner wall of a volute water inlet chamber includes a continuously rotating supersonic flame spray gun, a servo motor, an industrial robot, and a movable platform. The movable platform includes a movable platform body and supporting components. The industrial robot is mounted on the platform body. The platform body and supporting components cooperate to enable the movable platform to move stably around the inner wall of the volute water inlet chamber during the spraying process. The continuously rotating supersonic flame spray gun is connected to the end of the industrial robot and can rotate continuously in the same direction without being restricted by the spray gun pipeline.

[0006] In the above technical solution, the continuously rotating supersonic flame gun further includes a gun body shell, a gun barrel and a combustion chamber fixedly installed inside the gun body shell, and a reversing distributor; the front end of the combustion chamber is a Laval nozzle structure, and the rear end is a cavity structure. The rear end face of the gun barrel is sealed and fastened to the front end face of the combustion chamber. The front end of the gun barrel is pressed and fixed to the front end of the gun body shell by a fastening sealing cover. The reversing distributor is located at the rear of the gun body shell and includes a fixed part and a rotatable rotating part arranged coaxially. The fixed part is fixed relative to the industrial robot arm. Various pipelines of the flame gun enter the reversing distributor through the fixed part and then enter the combustion chamber through the rotating part. The rotating part is fixed to the gun body shell and driven by a servo motor, thereby driving the flame gun to rotate without being restricted by the pipelines.

[0007] Furthermore, in the reversing distributor, the fixed part and the rotating part are coaxially arranged. The fixed part has N axial holes on its end face and N radial holes on its circumferential surface near the rotating part. The N axial holes have different depths and are connected to the N radial holes one by one to form N channels. N circumferential grooves are distributed on the circumferential surface, and the positions of the circumferential grooves and the radial holes are one by one. After the fixed part and the rotating part are engaged, ball bearings and sealing rings are provided between the grooves to form a dynamic seal between the fixed part and the rotating part. The rotating part has N outlets on its circumferential surface, which are connected to the N grooves one by one. The spray gun pipeline is connected to the fixed part and enters the interior of the spray gun through the axial holes, radial holes, grooves, and outlets.

[0008] Furthermore, the combustion chamber is equipped with a disc-shaped high-temperature resistant porous flow stabilizer with many through holes on its end face and a through hole in its shaft. The powder feeding needle is sealed to the rear cover of the combustion chamber, and one end of the needle passes through the rear cover of the combustion chamber and extends into the through hole of the high-temperature resistant porous flow stabilizer. The other end is connected to one end of the powder feeding column on the outside of the rear cover of the combustion chamber through a bent connector. The powder feeding column is a cylinder with a through hole in its shaft. The other end is fixed to the rear cover of the gun body and connected to the external powder feeding pipe. The powder feeding column and the bent connector adopt a axial dynamic sealing structure, and the powder feeding needle and the bent connector adopt a fixed sealing structure.

[0009] Furthermore, an air passage, a fuel passage, an oxygen passage, a nitrogen passage, and a water cooling passage are provided between the integrated structure formed by the barrel and the combustion chamber and the outer shell of the gun body. At least three circumferential grooves are opened on the outer wall of the cavity structure of the combustion chamber, which respectively connect to the air passage, the fuel passage, and the oxygen passage. The grooves are sealed with sealing rings, and each groove has many small holes that connect to the combustion chamber.

[0010] Furthermore, the mobile platform has wheels at the bottom of its main body, and an internal battery power system drives the wheels to move. The support components are hydraulic support columns, with at least one hydraulic support column fixed on the platform surface of the main body. Additionally, hydraulic support columns can also be fixedly installed on the side of the main body. All hydraulic support columns have small wheels installed at their ends, and all of them abut against the surface of the volute. The hydraulic support columns apply force to the mobile platform, restricting the degree of freedom of the mobile platform within the volute, ensuring the stability of the mobile platform while simultaneously ensuring that the mobile platform can move.

[0011] Furthermore, the device also includes a video monitoring system and an integrated control cabinet, both of which are installed on the main body of the mobile platform. The video monitoring system is used to monitor the spraying process in real time, and the integrated control cabinet is used to control the spray gun parameters, the movement trajectory of the industrial robot, the video monitoring system, the movement of the main body of the platform, and the support force of the supporting components.

[0012] A method for supersonic flame thermal spraying of the inner wall of the vortex casing of a large water turbine is as follows:

[0013] 1. The spraying direction is from the inside out, that is, starting from the furthest point of the volute from the exit. The moving platform moves along the volute towards the exit.

[0014] 2. The angular velocity of the continuously rotating supersonic flame spray gun is equal to the angular velocity of the spray gun moving in a circle along the inner surface of the volute controlled by the robotic arm, and the movement trajectory is consistent with the distance of the inner surface of the volute, i.e. the flame spraying distance. The spraying distance must be within the reasonable range of the process.

[0015] 3. The time it takes for the spray gun to move one flame width along the axis of the volute is equal to the time it takes for the spray gun to rotate one revolution. That is, assuming the flame width is d, the speed v at which the moving platform or industrial robot moves the spray gun towards the axis of the volute is t1, the angular velocity of the spray gun is ω, and the time for one revolution is t2, then ensuring…

[0016] IV. Because the spraying area of ​​a single volute water inlet chamber is typically very large, considering the lifespan of spray gun parts, the replacement of nitrogen, fuel gas, and oxygen, and the addition of spraying material, a segmented spraying scheme is recommended. This means that after spraying one section of the volute's inner wall, the spray gun and industrial robot can stop working to check for equipment problems, whether spraying material needs to be added, and whether fuel gas and oxygen need to be replenished. The moving platform then moves a certain distance along the volute's axis towards the outlet and stops. Once everything is ready, the industrial robot and spray gun can be restarted to spray the next section of the volute. Alternatively, during spraying, the moving platform can be moved simultaneously along the volute's axis to control the spray gun's movement along that axis. In this case, the industrial robot only controls the overall circular movement of the spray gun, and the spray gun rotation is achieved solely through a servo motor. This way, the spraying area is not limited by the robot's range of motion, allowing for continuous spraying of larger areas.

[0017] It's important to emphasize that the rotation of the spray gun is independent of the robotic arm and the moving platform. The circular trajectory of the spray gun's overall movement is controlled by the industrial robotic arm. There are two working modes for the overall axial movement of the spray gun. In the first mode, after the moving platform moves to a spraying position, the hydraulic support column rises and supports the volute. The moving platform then remains stationary, and the movement of the spray gun along the volute's axis is controlled by the robotic arm. Because the moving platform is fixed, the spray gun's trajectory is entirely controlled by the robotic arm, resulting in high precision, suitable for spraying scenarios requiring high accuracy. However, due to the limited range of motion of the robotic arm, spraying can only be done in small segments. After spraying one area, spraying must stop, and then the moving platform moves to the next spraying point to spray the next segment. This method has slightly lower spraying efficiency. The second mode controls the overall axial movement of the spray gun along the volute's axis through the moving platform. The moving platform controls the spray gun's axial movement along the volute, the circular movement of the spray gun is controlled by the robotic arm, and the rotation of the spray gun is controlled by a servo motor. This allows the entire device to move while spraying, resulting in higher efficiency. However, because the moving platform is not as precise as a robotic arm, this method is suitable for situations where spraying precision requirements are not high and the spray gun jet is large.

[0018] The spraying trajectory is a spiral trajectory, which makes the spraying trajectory continuous, with fewer trajectory joints and uniform coating thickness. If the spraying trajectory is to spray one circle of the volute (the width of the beam) and then spray the next circle, and so on, there will inevitably be pauses and joints between the circles, resulting in inconsistent coating thickness and poor quality of the coating overlap area.

[0019] The innovative effects of this invention are:

[0020] This invention provides a supersonic flame thermal spraying device and method for the inner wall of a volute water inlet chamber. This method can replace the manual supersonic flame spraying of large volute water inlet chambers in practical engineering applications. It solves the problem of pipe entanglement and twisting during continuous rotating spraying due to limitations in the supersonic flame spray gun's pipeline; it also solves the problem of severe coating buildup at bends due to slow speed during reciprocating motion of the volute spraying trajectory, thus affecting coating quality. This significantly improves engineering efficiency, enhances coating uniformity, and saves on spraying materials and gas consumption, making it highly valuable for practical engineering applications. Attached Figure Description

[0021] Figure 1 A schematic diagram of a supersonic flame thermal spraying device for the inner wall of a volute water intake chamber according to the present invention includes: 1-a continuously rotating supersonic flame spray gun, 2-a rotatable frustum, 3-a servo motor, 4-an industrial robot, 5-a mobile base, 6-volute, 7-a stable hydraulic column, 8-a video monitoring system, and 9-an integrated control cabinet.

[0022] Figure 2 A schematic diagram of a continuously rotating supersonic flame spray gun: 101-Secure sealing cover, 102-Gun body shell, 103-Gun barrel, 104-Combustion chamber, 105-High temperature resistant porous flow stabilizer, 106-Cooling water return channel, 107-Cooling water inlet channel, 108-Gas mixing chamber, 109-Combustion chamber rear cover, 110-Gun body rear cover, 111-Gun body rear cover, 112-Reversing distributor, 113-Compressed air channel, 114-Nitrogen channel, 115-Oxygen channel, 116-Fuel channel, 117-Air channel shell, 118-Fuel channel shell, 119-Oxygen channel shell, 120-Nitrogen channel shell, 121-Spray gun pipeline.

[0023] Figure 3 A schematic diagram of a reversing distributor, sectional view AA of the reversing distributor, and enlarged view B of a portion thereof; 1121-rear cover, 1122-sealing sleeve, 1123-ball bearing, 1124-distribution core, 1125-rotating shaft, 1126-dynamic sealing ring.

[0024] Figure 4 A schematic diagram of a commutator distributor core;

[0025] Figure 5 A schematic diagram of the structure of the distribution core end face of a commutator distributor.

[0026] Figure 6 Schematic diagram of a rotatable frustum, 201-base, 202-bearing, 203-frustum;

[0027] Figure 7 A schematic diagram of a combustion chamber structure, sectional view of the combustion chamber BB.

[0028] Figure 8 A schematic diagram of a hydraulic support column, 701-top hydraulic support column, 702-right hydraulic support column, 703-left hydraulic support column.

[0029] Figure 9 Spraying trajectory diagram, 401 - spray gun movement trajectory. Detailed Implementation

[0030] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The purpose and effects of the present invention will become clearer. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0031] This invention discloses a supersonic flame thermal spraying device for the inner wall of the volute intake chamber of a large hydraulic turbine, comprising a continuously rotating supersonic flame spray gun, a rotating frustum, a servo motor, an industrial robot, an integrated control cabinet, a video monitoring system, a movable platform, and a stabilizing hydraulic column. The continuously rotating supersonic flame spray gun features a novel cooling water circuit, fuel channel, oxygen channel, compressed air channel, nitrogen channel (powder delivery channel), and gun body structure; thus solving the problem of nozzle entanglement caused by continuous rotation of the supersonic flame spray gun in one direction due to nozzle piping limitations.

[0032] Furthermore, according to an embodiment of the present invention, the continuously rotating supersonic flame gun mainly includes: a reversing distributor, a nitrogen channel housing, a fuel channel housing, an oxygen channel housing, an air housing, a barrel, a combustion chamber, a combustion chamber rear cover, a high-temperature resistant porous flow stabilizer, a gun body housing, and a gun body rear cover, etc.

[0033] Furthermore, according to an embodiment of the present invention, the reversing distributor is located at the rear of the gun body shell and includes a fixed part and a rotatable rotating part arranged coaxially, or may also include other functional components for ensuring the rotation of the rotating part. The fixed part is fixed relative to the industrial robot arm, and various pipelines of the spray gun enter the reversing distributor through the fixed part and then enter the combustion chamber through the rotating part. The rotating part is fixed to the gun body shell and driven by a servo motor, thereby driving the spray gun to rotate without being restricted by the pipelines.

[0034] Furthermore, according to one embodiment of the present invention, the space enclosed by the gun body shell, the nitrogen gas passage shell, the combustion chamber, and the gun barrel is a cooling water circulation channel.

[0035] Furthermore, according to one embodiment of the present invention, the nitrogen passage shell, fuel passage shell, oxygen passage shell, and air passage shell are tightly fitted to the combustion chamber and sealed with O-rings. The four passages enclosed by the combustion chamber and the reversing distributor are respectively used to transmit nitrogen, fuel, oxygen, and air into the combustion chamber.

[0036] Furthermore, according to one embodiment of the present invention, the combustion chamber has a cylindrical cavity structure at the rear end and four shallow grooves around the circumference on the side, with many small holes inside the grooves. The four circumferential grooves correspond to the nitrogen passage, fuel passage, oxygen passage and air passage, respectively, and the front end of the combustion chamber is a Laval nozzle structure.

[0037] Furthermore, according to one embodiment of the present invention, the rear end face of the barrel is in close contact with the front end face of the combustion chamber and is pressed and sealed by a fastening disc, which can be fastened by bolts; the front end of the barrel abuts against a fastening sealing cover, and the two are sealed by an O-ring, wherein the fastening sealing cover is threadedly connected to the gun body shell and sealed by an O-ring.

[0038] Furthermore, according to one embodiment of the present invention, the high-temperature resistant porous flow stabilizer is disc-shaped with many small through holes on its end face. The space enclosed by the combustion chamber rear cover and the combustion chamber serves as a mixing zone for fuel, oxygen, and air. The function of the high-temperature resistant porous flow stabilizer is to allow the mixed gas to be delivered more evenly into the combustion zone. The side of the high-temperature resistant porous flow stabilizer is threadedly fastened to the inner wall of the combustion chamber.

[0039] Furthermore, according to one embodiment of the present invention, the combustion chamber rear cover is threadedly connected to the combustion chamber and sealed with a sealing ring.

[0040] Furthermore, according to one embodiment of the present invention, the rotatable frustum has a base fastened to the end of the robotic arm by bolts, a bearing between the platform and the base allowing free rotation, and the platform is fixedly connected to the spray gun housing by screws. The rotatable frustum is hollow inside, with a small servo motor built into the axis of the base. The axis of the servo motor shaft is collinear with the axis of the rotatable frustum, and the shaft of the servo motor is connected to the rotating shaft of the reversing distributor via a coupling. The main function of the rotatable frustum is to provide sufficient support for the rotatable spray gun and to connect the rotatable spray gun to the industrial robotic arm.

[0041] The industrial robot arm mentioned above can be a common five-axis or six-axis robot arm.

[0042] Furthermore, according to one embodiment of the present invention, the main body of the mobile platform can be trapezoidal in shape, wider at the top and narrower at the bottom, with anti-slip wheels at the bottom, and a battery power system can be installed inside. The mobile platform can move back and forth, and an industrial robot, integrated control cabinet, monitoring camera, and hydraulic support column can be placed on the platform.

[0043] The hydraulic support columns consist of one hydraulic rod mounted on the platform of the movable base, and four other hydraulic support columns mounted on both sides of the movable base, two on each side. The five hydraulic support columns rest against the surface of the volute housing, applying force to the movable base and restricting its degrees of freedom within the volute housing to ensure stability. Multiple anti-slip wheels are also installed at the ends of the hydraulic support columns to ensure that the movable base can move while the hydraulic support columns provide pressure.

[0044] The integrated control cabinet mainly controls the adjustment of spray gun parameters, robot trajectory programming, monitoring system adjustment, moving speed and distance of the mobile platform, and support force control of the hydraulic support column. It can be placed on the mobile platform or installed outside the volute.

[0045] The monitoring system described above has cameras mounted on the surface of a mobile platform.

[0046] According to a specific embodiment of the present invention, Figure 1 This is a schematic diagram of a supersonic flame thermal spraying device for the inner wall of the volute inlet chamber of a large water turbine. Figure 2 This is a structural detail diagram of an example of a continuously rotating supersonic flame torch. Figure 3 This is a schematic diagram of a commutation distributor.

[0047] The continuously rotating supersonic flame gun 1 is bolted to the platform 203 of the rotatable frustum 2, and the bottom surface of the base 201 of the rotatable frustum 2 is bolted to the end of the industrial robot 4. The platform can rotate freely relative to the base. The servo motor 3 is mounted on the base 201 of the rotatable frustum 2 and fixed with screws. The rotation shaft of the servo motor 3 is coaxial with the rotation shaft 1125 of the reversing distributor 112 and connected by a coupling. The rotation shaft 1125 is also coaxial with the bearing 202, ensuring smooth rotation of the flame gun.

[0048] The mobile platform 5 includes a platform body and supporting components. The platform body is trapezoidal in shape, wider at the top and narrower at the bottom, with wheels at the bottom. A battery power system can be installed inside the platform body to drive the wheels to rotate, and the movement of the mobile platform 5 is controlled by an integrated control system. The industrial robot arm 4 is fixed to the platform surface of the mobile platform 5 with bolts.

[0049] Reference Figure 8According to a specific embodiment of the present invention, the support component is implemented using hydraulic support columns 7, of which five are provided. The top hydraulic support column 701 is mounted on the platform of the movable base, and the other four hydraulic support columns are respectively mounted on the two sides of the movable base. Two hydraulic support columns 702 are mounted on the right side, and two hydraulic support columns 703 are mounted on the left side. The five hydraulic support columns abut against the surface of the volute, applying force to the movable base 5, restricting the degree of freedom of the movable base 5 within the volute, and ensuring the stability of the movable base 5. Multiple anti-slip small wheels are installed at the ends of the hydraulic support columns to ensure that the movable base 5 can move while the hydraulic support columns provide pressure.

[0050] The camera of the video monitoring system 8 is installed at a suitable position on the table of the mobile platform 5 to monitor the spraying process in real time.

[0051] The integrated control cabinet 9 is also bolted to a suitable position on the movable platform 5. The integrated control cabinet 9 mainly controls the adjustment of spray gun parameters, the trajectory programming of industrial robot, the adjustment of monitoring system, the moving speed and distance of movable platform, and the support force control of hydraulic support column, etc.

[0052] Furthermore, referring to Figure 1 and Figure 2 The innovative design incorporates a reversing distribution core 112, a cooling water inlet channel 107, a cooling water return channel 106, a nitrogen channel 114, an oxygen channel 115, a fuel channel 116, a compressed air channel 113, a rotatable frustum 2, and a gun body structure. This design changes the traditional air intake and water supply methods, enabling the spray gun to rotate 360 ​​degrees. It also solves the problem of pipe entanglement during the spray gun's rotation. The main components of the continuously rotating supersonic flame spray gun 1 are as follows: fastening sealing cover 101, gun body shell 102, gun barrel 103, combustion chamber 104, high temperature resistant porous flow stabilizer 105, cooling water return channel 106, cooling water inlet channel 107, gas mixing chamber 108, combustion chamber rear cover 109, gun body rear cover 110, gun body rear cover 111, reversing distributor 112, compressed air channel 113, nitrogen channel 114, oxygen channel 115, fuel channel 116, air channel shell 117, fuel channel shell 118, oxygen channel shell 119, nitrogen channel shell 120, and spray gun pipeline 121.

[0053] The space enclosed by the gun body shell 102, the nitrogen passage shell 120, the combustion chamber 104, and the gun barrel 103 is the cooling water circulation channel, namely the cooling water return channel 106 and the cooling water inlet channel 107.

[0054] The space between the nitrogen channel housing 120 and the oxygen channel housing 119 serves as the nitrogen channel 114; the space between the oxygen channel housing 119 and the fuel channel housing 118 serves as the oxygen channel 115; the space between the fuel channel housing 118 and the air channel housing 117 serves as the fuel channel 116; and the space between the air channel housing 117 and the gun body rear cover 111 serves as the compressed air channel 113.

[0055] The rear end face of the barrel 103 is in close contact with the front end face of the combustion chamber 104 and is sealed by a fastening disc, which can be fastened with bolts. The front end of the barrel 103 abuts against a fastening sealing cover 101, which can stabilize the outlet of the barrel 103 and prevent the front end of the barrel 103 from shaking during spraying. The fastening sealing cover 101 is threaded to the gun body shell 102 and sealed with a rubber sealing ring to prevent cooling water from overflowing.

[0056] And refer to Figure 7 A schematic diagram of a combustion chamber is shown. The rear end of the combustion chamber 104 is a cylindrical cavity structure with four shallow grooves on its side, each containing numerous small holes. These grooves correspond to the nitrogen passage 114, oxygen passage 115, fuel passage 116, and air passage 113, respectively. O-rings seal the grooves. The front end of the combustion chamber 104 features a Laval nozzle structure. The combustion chamber 104 is threadedly connected to the high-temperature porous flow stabilizer 105, the rear cover 109, and also threadedly connected to the air passage housing 117, fuel passage housing 118, oxygen passage housing 119, and nitrogen passage housing 120, all sealed with O-rings.

[0057] The high-temperature resistant porous flow stabilizer 105 is a disc-shaped device with many small through holes on its end face. The space enclosed by the combustion chamber rear cover 109 and the combustion chamber 104 is used as a mixing zone for fuel, oxygen and air. The function of the high-temperature resistant porous flow stabilizer 105 is to allow the mixed gas to be delivered into the combustion zone more evenly, making the combustion more stable and uniform.

[0058] In this invention, the reversing distributor is located at the rear of the gun body shell and includes a fixed part and a rotatable rotating part coaxially arranged. The fixed part is fixed relative to the industrial robot arm. Various pipelines of the spray gun enter the reversing distributor through the fixed part and then enter the combustion chamber through the rotating part. The rotating part is fixed to the gun body shell and driven by a servo motor, thereby causing the spray gun to rotate without being restricted by the pipelines. The rotating part can be located inside or outside the fixed part, see reference. Figure 3 , Figure 4 and Figure 5This diagram illustrates a specific structure of a reversing distributor 112, an example where the rotating part is mainly located outside the fixed part. It mainly includes: a rear cover 1121, a sealing sleeve 1122, a ball bearing 1123, a distribution core 1124, a rotating shaft 1125, and a rotating dynamic sealing ring 1126. The distribution core 1124 (in this example, the fixed part) is cylindrical, with six holes evenly distributed around the center of its end face. These six holes connect to external water inlet pipes, water return pipes, nitrogen pipes, combustion pipes, oxygen pipes, and air pipes, respectively. The six holes extend axially inward from the end face, with varying depths. Six holes also extend radially from the side of the distribution core, corresponding one-to-one with the six axial holes and communicating to form six independent channels. The side surface of the distribution core 1124 has six circumferential grooves, each corresponding to a radial hole on the side. The function of the rotating part is to act as a channel connecting the holes on the sealing sleeve 1122 and the distribution core 1124 when the sealing sleeve 1122 (in this example, the rotating part) and the distribution core 1124 rotate relative to each other. This allows cooling water, fuel, oxygen, air, and nitrogen to continuously enter from the end holes of the reversing distributor 112 and exit from the side holes of the reversing distributor 112, entering the interior of the spray gun. The outer surface of the distribution core 1124 and the inner surface of the sealing sleeve 1122 also have many shallow grooves. The ball bearings 1123 are placed in these shallow grooves, enabling smoother rotation between the distribution core 1124 and the sealing sleeve 1122. Multiple rotating dynamic sealing rings 1126 are respectively placed between the grooves, forming a dynamic seal between the distribution core 1124 and the sealing sleeve 1122, ensuring that the channels between the grooves are independent and not interconnected. The distribution core 1124 has a through hole in its shaft, through which the rotating shaft 1125 passes. The rotating shaft 1125 is fixedly connected to the rear cover 1121 with screws; the sealing sleeve 1122 is also fixedly connected to the rear cover 1121 with screws. The servo motor 3 drives the rotating shaft 1125 to rotate, thereby driving the sealing sleeve 1122 to rotate. The sealing sleeve 1122 is fixedly connected to the gun body rear cover 111 with screws, thus driving the entire spray gun to rotate.

[0059] According to a specific example of the present invention, referring to Figure 6 A rotatable frustum 2 is provided, with a base 201 fastened to the end of a robotic arm 4 by bolts. A bearing 202 connects the platform 203 to the base 201, allowing it to rotate around an axis. The platform 203 is fixed to the nozzle housing 102 and the nozzle rear cover 111 by screws. The rotatable frustum 2 is hollow internally, with a small servo motor 3 built into the axis of the base 201. The axis of the servo motor is collinear with the axis of the rotatable frustum 2, and the shaft of the servo motor 3 is connected to the rotating shaft 1125 of the reversing distributor 112 via a coupling. The main function of the rotatable frustum 2 is to provide sufficient support for the rotatable supersonic flame torch 1 and to connect the rotatable supersonic flame torch 1 to the industrial robotic arm 4.

[0060] The working method of the supersonic flame thermal spraying device for the inner wall of a large spiral-shaped water intake chamber according to the present invention is as follows:

[0061] 1. After the pretreatment process of the volute 6 substrate, including rust removal, cleaning, and sandblasting, the device of this invention is moved to the deepest part of the volute 6. Spraying begins from the deepest part of the volute 6 and then proceeds sequentially towards the exit direction. The moving platform 5 moves along the volute axial direction towards the exit. The device simultaneously moves along the volute axial line towards the exit, the robotic arm moves in circles along the inner surface of the volute, and the spray gun rotates, resulting in a final spraying trajectory that is a spiral motion.

[0062] 2. This embodiment adopts a high-precision working scheme: After the mobile platform 5 moves to a spraying construction position, the hydraulic support column 7 rises and supports the volute 6, keeping the mobile platform 5 stationary. The movement of the continuously rotating supersonic flame spray gun 1 along the axial direction of the volute 6 is controlled by the programming of the industrial robot 4, and the movement trajectory 401 of the spray gun is also controlled by the programming of the industrial robot 4; the rotation control of the continuously rotating supersonic flame spray gun 1 is controlled by the servo motor 3.

[0063] 3. Check if any components of the device are functioning correctly. Then, program the movement trajectory of the industrial robot arm 4 and the rotation of the servo motor 3. After programming, run the program once without ignition to ensure there are no problems. The parameters set above must meet the following requirements:

[0064] (1)Reference Figure 9 The angular velocity of the continuously rotating supersonic flame spray gun 1 is equal to the angular velocity of the industrial robot 4 controlling the spray gun 1 to move in a circle along the inner surface of the volute, ensuring that the direction of the flame sprayed by the supersonic flame spray gun 1 is always perpendicular to the inner surface of the volute 6 during the circular movement, and that the distance between the moving trajectory 401 and the inner surface of the volute 6, i.e. the flame spraying distance, is consistent, and the spraying distance must be within the reasonable range of the process.

[0065] (2) The time it takes for the continuously rotating supersonic flame torch 1 to move one flame width along the axis of the volute 6 is equal to the time it takes for the torch to rotate one revolution. That is, assuming a flame width of d, the moving platform 5 or industrial robot 4 drives the continuously rotating supersonic flame torch 1 to move at a speed of v towards the axis of the volute 6, the time required is t1, the angular velocity of the continuously rotating supersonic flame torch 1 is ω, and the time for one revolution is t2. Then, ensuring…

[0066] 4. Start the cooling water circulation, and start the supply of nitrogen, oxygen, air and fuel gas. Manually ignite the gun with a flint and steel, run the program, and preheat to ensure that the temperature of the area to be coated on the volute 6 is within the process range. Feed powder according to the set powder feeding amount, and run the program multiple times to perform supersonic flame spraying.

[0067] 5. Once the coating thickness in the sprayed area reaches the required level, turn off the gas, stop the gas supply, and stop spraying; retract the hydraulic support column 7 and move the movable platform 5 to the next construction position, repeating steps 2, 3, and 4; and so on, until the coating work on the volute 6 is completely completed.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, or alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A device for supersonic flame spraying of the inner wall of a volute draft chamber, characterized in that The continuous rotation supersonic flame spraying gun, the servo motor, the industrial robot, and the mobile base are connected. The continuous rotation supersonic flame spraying gun comprises a gun body shell, a gun barrel and a combustion chamber fixed in the gun body shell, and a reversing distributor. The front end of the combustion chamber is a Laval nozzle structure, and the rear end is a cavity structure. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part.

2. The volute draft tube inner wall high velocity oxy-fuel thermal spray apparatus of claim 1, wherein, The bottom of the base body of the mobile base is provided with wheels, and an internal battery power system is arranged to drive the wheels to move. The support part is a hydraulic support column. The combustion chamber is provided with a disc-shaped high-temperature-resistant porous flow stabilizer. The front end of the combustion chamber is a Laval nozzle structure, and the rear end is a cavity structure. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, and the rear end face of the gun barrel is tightly fixed with the front end of the gun body shell. The rear end face of the gun barrel is tightly fixed with the front end of the gun body shell through a tight sealing cover, and the tail of the gun body shell is provided with the reversing distributor. The fixed part of the reversing distributor is coaxially arranged with the rotating part, and N axial holes are arranged on the end face of the fixed part. The front end of the gun barrel is tightly fixed with the front end face of the combustion chamber through a tight sealing cover, 3. The volute draft tube inner wall thermal spray apparatus of claim 1, wherein, The air passage, fuel passage, oxygen passage and water cooling passage are isolated from each other between the integrated structure formed by the barrel and the combustion chamber and the gun body shell.

4. The volute draft tube inner wall thermal spray apparatus of claim 1, wherein, The device also comprises a video monitoring system and an integrated control cabinet, which are installed on the seat body of the mobile seat, the video monitoring system is used for real-time monitoring of the spraying process, and the integrated control cabinet is used for controlling the spraying gun parameters, the industrial robot motion track, the video monitoring system, the movement of the seat body and the supporting degree of the supporting part.

5. A method of supersonic flame sprayed inner wall of a volute draft chamber, characterized in that, The device is implemented by using any one of claims 1-4, comprising: The spraying is performed from inside to outside in the spiral casing water inlet chamber, that is, the spraying is started from the position farthest from the outlet in the spiral casing, and the device simultaneously realizes the movement along the spiral casing axis to the outlet direction, the circular motion of the robot along the inner surface of the spiral casing and the rotary motion of the spraying gun, so that the final spraying motion track is a spiral motion track; In the spraying process, the angular velocity of the continuously rotatable supersonic flame spraying gun is equal to the angular velocity of the industrial robot for controlling the spraying gun to move along the spiral casing circumference as a concentric circle, and the distance between the moving track and the inner surface of the spiral casing, that is, the flame spraying distance, is kept consistent.

6. The method of super sonic flame sprayed volute draft tube inner wall of claim 5, wherein, The movement of the spraying gun along the spiral casing axis has two working modes, one is that after the moving platform moves to a spraying position, the hydraulic supporting column is raised to support the spiral casing, then the moving platform remains stationary, and the movement of the spraying gun along the spiral casing axis is controlled by the robot, at this time, because the moving platform is stationary, the moving track of the spraying gun is controlled by the robot, and the precision is high, which is suitable for high-precision spraying scenes, but because the motion range of the robot is limited, only a small section can be sprayed, after a region is sprayed, the spraying needs to be stopped, then the moving platform moves to the next spraying point to spray the next region, and this method has a slightly low spraying efficiency; the second scheme is that the movement of the spraying gun along the spiral casing axis is controlled by the moving platform, that is, the moving platform controls the movement of the spraying gun along the spiral casing axis, the circular movement of the spraying gun is controlled by the robot, and the rotation of the spraying gun is controlled by the servo motor, so that the whole device can move and spray at the same time, and the efficiency is high, but because the precision of the moving platform is lower than that of the robot, this method is suitable for occasions with low spraying precision and large spraying beam; The time for the spraying gun to move along the spiral casing axis by a flame width is equal to the time for the spraying gun to rotate one circle, that is, assuming that a flame width is d, the speed of the moving seat or the industrial robot for driving the spraying gun to move along the spiral casing axis is v, the required time is t1, the angular velocity of the spraying gun is ω, and the time for one rotation is t2, so that 7. The method of super sonic flame sprayed volute draft tube inner wall of claim 5, wherein, Considering the life of the spray gun parts, the addition of various types of spray materials and materials, the spraying scheme should adopt segmented circumferential spraying: (1) After spraying a segment of the circumferential area, the spray gun and industrial robot stop working, check if there is any problem with the equipment, check if the spray material needs to be added, check if the fuel gas and oxygen need to be supplemented, and move the moving platform along the axis of the spiral case to the outlet direction by a distance. Since the robot has a certain range of movement along the axis of the spiral case, this distance is the next area to be sprayed. After everything is ready, the industrial robot and spray gun are turned on again to spray the next area. At this time, the industrial robot controls the spray gun to move in a circular motion while retreating along the axis of the spiral case towards the outlet direction of the spiral case; or (2) During the spraying process of the spray gun, the moving platform only moves along the axis of the spiral case. At this time, the industrial robot only controls the spray gun to move in a circular motion. In this way, the spraying area is not limited by the movement range of the robot. The spraying area is limited by the axial extension of the spiral case, i.e. the above-mentioned movement along the axis of the spiral case has a certain range. When the movement along the axis of the spiral case is controlled by the moving platform, there is no such limitation. A larger area can be sprayed at a time. After spraying an area, check the equipment status, supplement the spray material and fuel gas, and then spray the next area.

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