CN115889344A - Device and method for removing coating by microwave plasma - Google Patents

Abstract

The invention discloses a device and a method for removing a coating by microwave plasma, which belong to the technical field of microwave plasma application and comprise a rectangular waveguide, a conversion part, a spraying device and an air inlet pipe; the spraying device comprises a shell and a spraying component; the microwave feeder is arranged at the left end of the rectangular waveguide, and the rectangular waveguide is connected with the shell through a conversion component; a plasma generating cavity is arranged in the shell; the conversion component is used for transmitting the microwaves in the rectangular waveguide to the plasma generation cavity; the gas inlet pipe is used for conveying reaction gas into the plasma generation cavity; the shell is provided with an injection component; the injection member is used for injecting plasma. The invention can effectively solve the problems of poor universality, low removal efficiency, easy damage to the surface of the base material and the like when the coating is removed by the traditional coating removing device.

Description

Device and method for removing coating by microwave plasma

Technical Field

The invention relates to the technical field of microwave plasma application, in particular to a device and a method for removing a coating by microwave plasma.

Background

The coating is a coating layer which is formed on the surface of a metal or nonmetal base body by a physical, chemical or other method, has a certain thickness, is different from the base body material and has certain strengthening, protecting or special functions, such as an engine coating, a camouflage coating, a stealth coating and the like. In the aerospace field, the stealth coating is coated on the surfaces of airplanes or missiles and the like, so that the observation characteristics of radar, infrared rays, photoelectricity, visual observation and the like are reduced, and the stealth coating is not easily discovered by enemy detectors in the process of sudden defense, thereby enhancing the attack abruptness and improving the viability and the fighting efficiency of the aircraft. However, the coating layer can be aged, cracked and even fall off gradually after being used for a long time, so that the coating layer fails. Therefore, after a certain period of service, the coating on the surface of the equipment must be quickly removed and then recoated.

In the prior art, the coating removal method mainly includes three types, including mechanical polishing, chemical treatment and laser removal. The mechanical polishing is to polish off a coating to be removed from the surface of a substrate by using a polishing tool, and because one surface of the substrate acted by the polishing tool is basically planar, the mechanical polishing is difficult to realize on the surface of a special-shaped structure, such as removing the coating on an airplane, the universality is poor, the treatment efficiency is extremely low, and the mechanical polishing is not easy to control and is easy to damage the surface of the substrate. The chemical treatment is to remove the coating by using a substance which has a chemical reaction with the coating on the surface of the substrate, and some chemical pollution is easily generated in the chemical treatment process, so that the problems of serious pollution, incomplete removal and the like exist. The laser removal is to irradiate the surface of the matrix coating by using high-energy laser beams, and the coating is evaporated or stripped based on the interaction between high-intensity beams and the coating; for example, chinese patent publication No. CN 216298282U discloses a laser coating removal device, which can achieve non-contact removal by laser removal, is suitable for various special-shaped structures, has high efficiency and no environmental pollution, but has excessive single-point accumulated energy during laser removal, is easy to damage the surface of a substrate, and more seriously causes potential safety hazards such as combustion.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a device and a method for removing a coating by microwave plasma, aiming at solving the problems of poor universality, low removal efficiency, easy damage to the surface of a base material and the like when the coating is removed by the conventional coating removing device. In order to achieve the purpose, the invention provides the following technical scheme:

a device for removing a coating by microwave plasma comprises a rectangular waveguide, a conversion part, a spraying device and an air inlet pipe; the spraying device comprises a shell and a spraying component; the microwave feeder is arranged at the left end of the rectangular waveguide, and the rectangular waveguide is connected with the shell through a conversion component; a plasma generating cavity is arranged in the shell; the conversion component is used for transmitting the microwaves in the rectangular waveguide to the plasma generation cavity; the gas inlet pipe is used for conveying reaction gas into the plasma generation cavity; the shell is provided with an injection component; the injection member is used for injecting plasma.

Furthermore, a metal shielding plate is arranged at the right end of the rectangular waveguide; the conversion part comprises a circular waveguide and a metal circular table; the lower surface of the rectangular waveguide is provided with a circular waveguide; the bottom of the circular waveguide is connected with a shell; the metal circular truncated cone is arranged at the top of the inner side of the rectangular waveguide; the air inlet pipe is a metal pipe; an air inlet channel is arranged in the center of the metal round table; the top of the air inlet channel is communicated with the outside, and the bottom of the air inlet channel is connected with a metal pipe; the metal pipe is positioned in the circular waveguide and is coaxially arranged; the metal round table is used for introducing microwaves in the rectangular waveguide into the space between the metal pipe and the round waveguide.

Further, the rectangular waveguide is movably connected with the circular waveguide; a first motor is arranged on the rectangular waveguide and connected with a first gear; a circle of first racks meshed with the first gear is arranged around the circular waveguide; the first motor is used for driving the first gear to rotate, so that the first gear drives the circular waveguide to rotate through the first rack.

Further, the shell is a conical shell; the diameter of the top of the conical shell is larger than that of the bottom of the conical shell; the side surface of the conical shell is provided with a strip-shaped opening and an injection pipe, and the bottom of the conical shell is provided with an injection cover; the strip-shaped opening is arranged along the direction of a bus of the conical shell; the strip-shaped port is used for jetting wide-width plasma; the jet pipe is used for jetting linear plasma; the spraying cover is used for spraying circular and/or annular plasma.

Further, an arc-shaped plate is arranged on the outer surface of the conical shell in a matched mode; the circular waveguide is provided with a second motor, and the second motor is connected with a second gear; a section of second rack meshed with the second gear is arranged on the arc-shaped plate; the second motor is used for driving the second gear to rotate, so that the second gear drives the arc plate to rotate by taking the axis of the conical shell as the center through the second rack; the arc-shaped plate is used for controlling the opening and closing of the strip-shaped opening.

Furthermore, a memory metal sheet is arranged on one side of the arc-shaped plate; and the memory metal sheet is provided with a strip-shaped plug corresponding to the strip-shaped opening.

Furthermore, a control valve is arranged on the injection pipe.

Further, the drift diameter of the injection cover is reduced from the top and the bottom to the middle; a second disc is fixed at the top of the injection cover; a first disc is fixed at the bottom of the conical shell; the second disc is rotatably connected with the first disc and is coaxially arranged; a plurality of second round holes are formed in the second disc; a plurality of first round holes which correspond to the second round holes one by one are arranged on the first disc; a third motor is arranged on the conical shell and connected with a third gear; a circle of third rack meshed with the third gear is arranged around the periphery of the second disk; the third motor is used for driving the third gear to rotate, so that the third gear drives the second disc to rotate through the third rack; the second round plate rotates relative to the first round plate, so that the second round hole is communicated with or staggered with the first round hole.

Further, the bottom of the second disc is connected with a cone through threads; the top of the cone is small and the bottom is large.

A method for removing a coating by microwave plasma adopts the device for removing the coating by microwave plasma, and an air inlet pipe conveys reaction gas into a plasma generating cavity; feeding microwaves into a microwave feed-in port arranged at the left end of the rectangular waveguide, and exciting plasma in a plasma generating cavity; the spraying part sprays plasma to the coating to be removed to remove the coating.

The invention has the beneficial effects that:

the invention discloses a device and a method for removing a coating by microwave plasma, which belong to the technical field of microwave plasma application and comprise a rectangular waveguide, a conversion part, a spraying device and an air inlet pipe; the spraying device comprises a shell and a spraying component; the microwave feeder is arranged at the left end of the rectangular waveguide, and the rectangular waveguide is connected with the shell through a conversion component; a plasma generating cavity is arranged in the shell; the conversion component is used for transmitting the microwaves in the rectangular waveguide to the plasma generation cavity; the gas inlet pipe is used for conveying reaction gas into the plasma generation cavity; the shell is provided with an injection component; the injection member is used for injecting plasma. The invention can effectively solve the problems of poor universality, low removal efficiency, easy damage to the surface of the base material and the like when the coating is removed by the conventional coating removing device.

Drawings

FIG. 1 is a front view of the whole structure of the microwave plasma coating removing device of the present invention;

FIG. 2 is a schematic diagram of the whole structure of the microwave plasma coating removing device of the invention;

FIG. 3 is a left side schematic view of the overall structure of the microwave plasma coating removal device of the present invention;

FIG. 4 is a schematic cross-sectional view of an apparatus for microwave plasma coating removal in accordance with the present invention;

FIG. 5 is an enlarged view of the structure at A in FIG. 4;

FIG. 6 is a bottom partial cross-sectional view of an apparatus for microwave plasma decoating in accordance with the present invention;

in the drawings: 1-rectangular waveguide, 2-injection device, 3-air inlet pipe, 4-metal shielding plate, 5-circular waveguide, 6-metal circular table, 7-metal pipe, 8-first motor, 9-first gear, 10-first rack, 11-conical shell, 12-strip port, 13-injection pipe, 14-injection cover, 15-arc plate, 16-second motor, 17-second gear, 18-second rack, 19-memory metal sheet, 20-control valve, 21-second disk, 22-first disk, 23-third motor, 24-third gear and 25-third rack.

Detailed Description

The present invention will be described in further detail below with reference to the drawings and the embodiments, but the present invention is not limited to the following examples.

The first embodiment is as follows:

see figures 1-6. A device for removing a coating by microwave plasma comprises a rectangular waveguide 1, a conversion part, an injection device 2 and an air inlet pipe 3; the spraying device 2 comprises a shell and a spraying component; the left end of the rectangular waveguide 1 is provided with a microwave feed inlet, and the rectangular waveguide 1 is connected with the shell through a conversion component; a plasma generating cavity is arranged in the shell; the conversion component is used for transmitting the microwaves in the rectangular waveguide 1 to the plasma generation cavity; the gas inlet pipe 3 is used for conveying reaction gas into the plasma generation cavity; the shell is provided with an injection component; the injection member is used for injecting plasma. According to the structure, the device for removing the coating by the microwave plasma comprises a rectangular waveguide 1, a conversion part, an injection device 2 and an air inlet pipe 3, wherein the left end of the rectangular waveguide 1 is provided with a microwave feed inlet, the left end of the rectangular waveguide 1 can be connected with a microwave source, the microwave source can be an existing solid-state source, the microwave frequency can be adjusted from 2.4GHz to 2.5GHz, and the microwave power can be adjusted from 10W to 250W, as shown in figures 1, 2 and 3. The microwave generated by the microwave source is fed in from a microwave feed-in port arranged at the left end of the rectangular waveguide 1; the injection device 2 comprises a shell and an injection part, wherein the shell surrounds a hollow cavity, namely a plasma generation cavity; the rectangular waveguide 1 is connected with the shell of the injection device 2 through a conversion part, and the conversion part can transmit microwaves in the rectangular waveguide 1 to a plasma generation cavity, so that the microwaves fed in from a microwave feed-in port arranged at the left end of the rectangular waveguide 1 are transmitted to the plasma generation cavity surrounded by the shell after the action of the conversion part; the gas inlet pipe 3 can convey reaction gas to the plasma generation cavity, the gas inlet pipe 3 can be arranged on the rectangular waveguide 1 or on the conversion component, the gas inlet pipe 3 comprises a gas inlet end and a gas outlet end, the gas inlet end of the gas inlet pipe 3 can be connected with a gas source, and the flow of the gas source can be adjusted between 1L/min and 10L/min. When the gas source is started, the reaction gas is conveyed into the plasma generation cavity through the gas inlet pipe 3, and the reaction gas can be oxygen or mixed gas of oxygen and carbon tetrafluoride. When the coating removing device works, firstly, the gas source is started, so that the reaction gas is conveyed into the plasma generating cavity through the gas inlet pipe 3; then starting a microwave source, feeding in microwave from a microwave feed-in port arranged at the left end of the rectangular waveguide 1, and transmitting the microwave into the plasma generation cavity after the action of the conversion part; the microwave electric field entering the plasma generating cavity will breakdown the reaction gas to generate plasma. The reaction gas conveyed to the plasma generating cavity enters from the gas inlet end of the gas inlet pipe 3 and is sprayed from the gas outlet end, and the gas source is continuously conveyed during working, so that the reaction gas forms a gas flow in the plasma generating cavity. After the microwave breaks down part of the reaction gas to generate plasma, the generated plasma can be ejected out of the ejection part along with the gas flow under the action of the continuously input reaction gas flow to form plasma flame, and the ejection part can be arranged at the bottom of the plasma generation cavity or on the side wall of the plasma generation cavity. The spraying part is aligned to the position of the substrate where the coating is to be removed, the plasma flame sprayed from the spraying part is sprayed to the position of the substrate where the coating is to be removed, and the oxygen active groups in the plasma flame and the coating to be removed are subjected to chemical reaction, so that the coating is removed. When the organic coating is removed, such as a stealth coating on an airplane, oxygen active groups in plasma flame and the stealth coating are subjected to chemical reaction, generated gas mainly comprises carbon dioxide and water and can be directly discharged into the air, the method is clean and environment-friendly, and the efficiency of the whole coating removing process is high. Because the temperature of the microwave plasma is low and the active groups only react with the coating, the coating material can be completely removed without causing any damage to the substrate. Meanwhile, the microwave plasma also has the surface modification effect, and after the coating is removed, the bonding reliability in the secondary coating process is enhanced. The coating removing device can also be provided with a mechanical arm, the action position of the spraying device 2 is adjusted through the movement of the mechanical arm, the spraying part of the device is aligned to the next area to be treated, and finally the cleaning of the whole coating is finished. Besides the removal of the stealth coating, the coating removing device can also be used for removing glue, paint and the like on the surface of the base material. The device for removing the coating by the microwave plasma removes the coating by the plasma, completely removes the coating material, does not damage the base material, and has high efficiency.

Example two:

see figures 1-6. On the basis of the first embodiment, a metal shielding plate 4 is arranged at the right end of the rectangular waveguide 1; the conversion component comprises a circular waveguide 5 and a metal circular table 6; a circular waveguide 5 is arranged on the lower surface of the rectangular waveguide 1; the bottom of the circular waveguide 5 is connected with a shell; the metal round table 6 is arranged at the top of the inner side of the rectangular waveguide 1; the air inlet pipe 3 is a metal pipe 7; an air inlet channel is arranged in the center of the metal round table 6; the top of the air inlet channel is communicated with the outside, and the bottom of the air inlet channel is connected with a metal pipe 7; the metal tube 7 is positioned in the circular waveguide 5 and is coaxially arranged; the metal round table 6 is used for introducing microwaves in the rectangular waveguide 1 into a space between the metal tube 7 and the round waveguide 5. According to the structure, the front side and the rear side of the rectangular waveguide 1 are narrow surfaces, the upper side and the lower side of the rectangular waveguide 1 are wide surfaces, the rectangular waveguide 1 is formed by the side surfaces of two size wide points and the side surfaces of two size narrow points in a surrounding mode, the side surfaces of the two size wide points are wide surfaces, the side surfaces of the two size narrow points are narrow surfaces, and microwaves can be better transmitted in the rectangular waveguide 1 after being fed in from a microwave feed inlet arranged at the left end of the rectangular waveguide 1. Meanwhile, the metal shielding plate 4 is arranged on the right side surface of the rectangular waveguide 1, so that the microwave fed from the microwave feed port arranged at the left end of the rectangular waveguide 1 can be prevented from leaking from the right end of the rectangular waveguide 1 and forming standing waves with reflected waves. The conversion part comprises a circular waveguide 5 and a metal circular table 6, the circular waveguide 5 is arranged on the lower surface of the rectangular waveguide 1, the axis of the circular waveguide 5 can extend in the up-down direction, the circular waveguide 5 is integrally and vertically arranged on the lower surface of the rectangular waveguide 1, an opening can be formed in the lower surface of the rectangular waveguide 1, the opening is connected with the circular waveguide 5 in a matched mode, and microwaves can be transmitted to the circular waveguide 5 from the opening of the rectangular waveguide 1 and finally transmitted to the plasma generation cavity. The rectangular waveguide 1 and the circular waveguide 5 can be fixedly connected or movably connected. The bottom of the circular waveguide 5 is connected with a shell, and the circular waveguide 5 and the shell can be fixedly connected. The metal round table 6 is arranged at the top of the inner side of the rectangular waveguide 1, the structure of the metal round table 6 can be as shown in fig. 3 and 4, the diameter of the upper bottom surface of the metal round table 6 is larger than that of the lower bottom surface, the diameter of the upper bottom surface of the metal round table 6 is larger than the width of the wide surface of the rectangular waveguide 1, and the joint of the front side and the back side of the metal round table and the narrow surface of the rectangular waveguide 1 is a plane. The gas inlet pipe 3 is a metal pipe 7, a gas inlet channel is arranged at the center of the metal round table 6, the top of the gas inlet channel is communicated with the outside, the bottom of the gas inlet channel is connected with the metal pipe 7, the gas inlet channel and the metal pipe 7 jointly form a channel for reaction gas to enter a plasma generation cavity, and an external gas source flows into the metal pipe 7 through the gas inlet channel and flows to the plasma generation cavity. The metal tube 7 is positioned in the circular waveguide 5 and is coaxially arranged, the circular waveguide 5 can at least partially contain the metal tube 7, the outer diameter of the metal tube 7 is smaller than the diameter of the circular waveguide 5, a gap is formed between the metal tube 7 and the circular waveguide 5, and the metal round table 6 is used for introducing microwaves in the rectangular waveguide 1 into the gap between the metal tube 7 and the circular waveguide 5. The upper end of the metal pipe 7 can penetrate through the upper end of the round waveguide 2 and extend into the rectangular waveguide 1, and the metal round platform 6 is arranged at the upper end of the metal pipe 7 as the upper end of the metal pipe 7 extends into the rectangular waveguide 1, so that the height of the metal round platform 6 is smaller than the width of the narrow surface of the rectangular waveguide 1. For example, chinese patent application No. 202211410535.7 discloses a microwave heating device and a method for heating materials, wherein the structure of a conversion part adopts a metal round table 6 and a circular waveguide 5, and the metal round table 6, the circular waveguide 5 and a metal tube 7 are matched, so that microwaves can be well fed into a plasma generation cavity from a rectangular waveguide 1 to form a relatively uniform electric field, thereby ionizing reaction gas, exciting plasma, and removing a coating device.

Example three:

see figures 1-6. On the basis of the second embodiment, the rectangular waveguide 1 is movably connected with the circular waveguide 5; a first motor 8 is arranged on the rectangular waveguide 1, and the first motor 8 is connected with a first gear 9; a circle of first racks 10 meshed with the first gear 9 is arranged around the periphery of the circular waveguide 5; the first motor 8 is used for driving the first gear 9 to rotate, so that the first gear 9 drives the circular waveguide 5 to rotate through the first rack 10. According to the structure, the rectangular waveguide 1 and the circular waveguide 5 are movably connected, as shown in fig. 4 and 5, a circle of L-shaped connecting structure is arranged on the lower surface of the rectangular waveguide 1, a circle of concave connecting structure capable of embedding the L-shaped connecting structure on the lower surface of the rectangular waveguide 1 is correspondingly arranged at the upper end of the circular waveguide 5, the two parts of connecting structures are matched with each other, so that the rectangular waveguide 1 and the circular waveguide 5 are connected together, the circular waveguide 5 can move relative to the rectangular waveguide 1, for example, rotate, a sealing ring can be arranged at the movable connection position of the rectangular waveguide 1 and the circular waveguide 5, and the air tightness of the coating removing device is ensured. Meanwhile, supports, such as ball supports, are arranged on the surfaces, contacting the tail end of the L-shaped connecting structure and the circular waveguide 5, so that the rectangular waveguide 1 and the circular waveguide 5 are not arranged in a clinging manner, and the friction force generated when the circular waveguide 5 rotates is reduced. By adopting the connecting structure, the gap at the connecting part of the rectangular waveguide 1 and the circular waveguide 5 is smaller, and after the microwave in the rectangular waveguide 1 is fed into the circular waveguide 5, the microwave cannot leak from the gap at the connecting part of the rectangular waveguide 1 and the circular waveguide 5, and even if the microwave leaks, only little microwave can leak, so that the normal operation of the device cannot be influenced. The rectangular waveguide 1 is provided with a first motor 8, the first motor 8 is connected with a first gear 9, a circle of first rack 10 meshed with the first gear 9 is arranged around the circular waveguide 5, when the first motor 8 works, the first gear 9 connected with the first motor is driven to rotate, and as the rectangular waveguide 1 is movably connected with the circular waveguide 5 and the first rack 10 is arranged on the periphery of the circular waveguide 5, the first gear 9 rotates to drive the first rack 10 meshed with the first gear to rotate, the circular waveguide 5 is finally driven to rotate. When the circular waveguide 5 rotates, the shell connected with the bottom of the circular waveguide 5 is driven to rotate, so that the spraying part arranged on the shell also rotates synchronously. When removing the coating, for the substrate with the deep hole, the device for removing the coating can not enter the deep hole, so that the coating in the deep hole is inconvenient to remove. For such deep holes, the part of the spraying device 2, namely the shell and the spraying part, can extend into the deep hole to remove the coating, for the coating on the side wall of the deep hole, the spraying part can be arranged on the side surface of the shell, and the first motor 8 is driven to ensure that the spraying part can rotate by 360 degrees, so that the coating on the side wall of the deep hole can be quickly removed. The device for removing the coating by the microwave plasma has high coating removing efficiency, can remove coatings in different shapes, and has good universality.

The shell is a conical shell body 11; the diameter of the top of the conical shell 11 is larger than that of the bottom; the side surface of the conical shell 11 is provided with a strip-shaped opening 12 and an injection pipe 13, and the bottom of the conical shell 11 is provided with an injection cover 14; the strip-shaped opening 12 is arranged along the generatrix direction of the conical shell 11; the strip-shaped port 12 is used for spraying wide-width plasma; the injection pipe 13 is used for injecting linear plasma; the spray hood 14 is used for spraying a circular and/or annular plasma. According to the structure, the shell is the conical shell 11, the diameter of the top of the conical shell 11 is larger than that of the bottom of the conical shell 11, and the diameter of the conical shell 11 is smaller as the conical shell is closer to the bottom of the conical shell 11. The outer shell is a conical shell 11, and a plasma generating cavity is arranged in the outer shell, so that the plasma generating cavity is also a conical cavity, the length of the plasma generating cavity is longer along the bus direction of the conical shell 11, and a strip-shaped opening can be arranged on the side wall of the conical shell 11, so that the sprayed plasma is wide plasma; secondly, after being fed in from the rectangular waveguide 1, the microwave enters the plasma generation cavity under the action of the conversion part, according to the property of the microwave electric field, the electric field at the far end of the plasma generation cavity is weaker than the electric field at the near end, the shell is set to be a conical shell 11, the diameter of the conical shell 11 at the far end part of the plasma generation cavity is smaller, the conical shell has a constraint effect on the electric field at the far end, so that the electric field at the far end is stronger, and the reaction gas can be ionized to generate plasma; then, the conical shell 11 with a conical structure can also converge the generated plasma at the bottom end, so that more plasma is sprayed outwards; and finally, the reaction gas enters the plasma generating cavity through the gas inlet pipe 3, the smaller the diameter of the bottom end of the conical shell 11 with the conical structure is, and after the reaction gas enters the plasma generating cavity, the airflow is continuously gathered, so that the pressure of the injected plasma is increased, and the injection distance is longer. Different injection components can be arranged on the conical shell 11 at different positions, so that the universality and the efficiency of the device are improved. The side surface of the conical shell 11 is provided with a strip-shaped opening 12, the strip-shaped opening 12 is arranged along the generatrix direction of the conical shell 11, and the strip-shaped opening 12 can be used for spraying wide-width plasma, for example, when a large-area coating or a coating on the side wall of a deep hole is removed, a spraying part with a strip-shaped opening 12 structure can be adopted; the side surface of the conical shell 11 is provided with the jet pipe 13, the jet pipe 13 with a tubular structure can be used for jetting linear plasma, for example, when a coating between an angle gap of two objects is removed, a jet part with the jet pipe 13 structure can be adopted; the bottom of the conical shell 11 is provided with a spraying cover 14, and the spraying cover 14 can be used for spraying circular and/or annular plasma, for example, when removing the coating on the raised part of the base layer or the coating with a specific annular structure, a spraying part with a spraying cover 14 structure can be adopted.

The outer surface of the conical shell 11 is provided with an arc-shaped plate 15 in a matching way; a second motor 16 is arranged on the circular waveguide 5, and the second motor 16 is connected with a second gear 17; a second rack 18 meshed with the second gear 17 is arranged on the arc-shaped plate 15; the second motor 16 is used for driving the second gear 17 to rotate, so that the second gear 17 drives the arc-shaped plate 15 to rotate by taking the axis of the conical shell 11 as the center through the second rack 18; the arc-shaped plate 15 is used for controlling the opening and closing of the strip-shaped opening 12. As can be seen from the above structure, the conical housing 11 is provided with a plurality of different injection members, and when only one of the injection members is used, the other injection members need to be closed, thereby preventing the microwave leakage and the plasma from being ejected from the other injection members to cause waste. The outer surface of the conical shell 11 is provided with an arc-shaped plate 15 in a matching manner, the arc-shaped plate 15 is used for controlling the opening and closing of the strip-shaped opening 12, the arc-shaped plate 15 can rotate around the axis of the conical shell 11 on the outer surface of the conical shell 11, for example, a circle of guide rail is arranged on the periphery of the top end and the bottom end of the conical shell 11, so that the arc-shaped plate 15 rotates along the guide rail. The circular waveguide 5 is provided with a second motor 16, the second motor 16 is connected with a second gear 17, the arc plate 15 is provided with a section of second rack 18 meshed with the second gear 17, when the second motor 16 works, the second gear 17 connected with the second motor is driven to rotate, because the arc plate 15 can rotate on the outer surface of the conical shell 11 and the arc plate 15 is provided with a section of second rack 18 meshed with the second gear 17, the second gear 17 rotates to drive the second rack 18 meshed with the second gear to rotate, and finally the arc plate 15 is driven to rotate by taking the axis of the conical shell 11 as the center. When the strip-shaped opening 12 is used, the second motor 16 is driven to rotate the arc-shaped plate 15 to a proper position, and the strip-shaped opening 12 is exposed; when the strip 12 is closed, the second motor 16 is driven to rotate the arc plate 15 to a proper position to shield the strip 12.

A memory metal sheet 19 is arranged on one side of the arc-shaped plate 15; the memory metal sheet 19 is provided with a strip plug corresponding to the strip port 12. It can be known from the above structure that the arc-shaped plate 15 is used for controlling the opening and closing of the strip-shaped opening 12, and when the arc-shaped plate 15 covers the strip-shaped opening 12, a small amount of microwaves may still leak out from the strip-shaped opening 12, and then leak along the gap between the arc-shaped plate 15 and the conical shell 11. Therefore, a memory metal sheet 19 is arranged on one side of the arc-shaped plate 15, a strip-shaped plug corresponding to the strip-shaped opening 12 is arranged on the memory metal sheet 19, and the strip-shaped plug can be plugged into the strip-shaped opening 12 to avoid microwave leakage. The memory metal sheet 19 may be made of a titanium alloy. When the strip-shaped opening 12 is used, the arc-shaped plate 15 rotates, and the memory metal sheet 19 on the side edge of the arc-shaped plate 15 deforms under the pulling action, so that the strip-shaped plug is pulled out of the strip-shaped opening 12, and wide plasma can be sprayed through the strip-shaped opening 12; when the strip-shaped opening 12 is closed, the arc-shaped plate 15 moves reversely, the memory metal sheet 19 can restore to the original shape due to the characteristics of the memory metal sheet, and the force towards the strip-shaped opening 12 is applied to the strip-shaped plug, so that the strip-shaped plug can be well plugged into the strip-shaped opening 12. Because the shell is the conical shell 11, the inner side diameter of the conical shell 11 is small, and the outer side diameter is large. The side surface of the conical shell 11 is provided with a strip-shaped opening 12, the strip-shaped opening 12 can also be set to be of a structure with small inner width, large outer width and trapezoidal cross section, and the corresponding strip-shaped plug is set to be in the same trapezoidal shape, so that firstly, the strip-shaped opening 12 is large in outer width and is convenient to pull out the strip-shaped plug; secondly, the width of the inner side of the strip-shaped port 12 with the trapezoid structure is smaller, so that the leakage of microwaves is reduced; and thirdly, the strip-shaped opening 12 with a small inner part and a large outer part is of a spraying structure, so that relatively wide plasma can be sprayed. Moreover, through the strip-shaped plug arranged on the memory metal sheet 19, when the pressure in the plasma generation cavity is higher, the pressure can push the strip-shaped plug and the memory metal sheet 19 to move outwards, the internal pressure is discharged from the strip-shaped opening 12, the purpose of pressure relief is achieved, and the phenomenon that the pressure in the plasma generation cavity is too high to cause more serious consequences is prevented.

The injection pipe 13 is provided with a control valve 20. As can be seen from the above configuration, the control valve 20 is provided in the injection pipe 13, the control valve 20 can control the opening and closing of the injection pipe 13, and the control valve 20 can be an electromagnetic valve. When the control valve 20 is opened, plasma is made to be injectable through the injection pipe 13; when the control valve 20 is closed, plasma may be injected through other injection parts.

The drift diameter of the injection hood 14 is reduced from the top and the bottom to the middle; a second disc 21 is fixed on the top of the injection cover 14; a first disc 22 is fixed at the bottom of the conical shell 11; the second disc 21 is rotatably connected with the first disc 22 and is coaxially arranged; a plurality of second round holes are formed in the second disc 21; a plurality of first round holes corresponding to the second round holes one by one are arranged on the first disc 22; a third motor 23 is arranged on the conical shell 11, and the third motor 23 is connected with a third gear 24; a circle of third racks 25 meshed with the third gear 24 is wound around the periphery of the second disk 21; the third motor 23 is used for driving the third gear 24 to rotate, so that the third gear 24 drives the second disc 21 to rotate through the third rack 25; the second disk 21 rotates relative to the first disk 22, so that the second circular hole is communicated with or dislocated with the first circular hole. According to the structure, the injection cover 14 is arranged at the bottom of the conical shell 11, the first disk 22 is fixed at the bottom of the conical shell 11, the second disk 21 is fixed at the top of the injection cover 14, the second disk 21 is rotatably connected with the first disk 22 and is coaxially arranged, and when the second disk 21 rotates, the injection cover 14 is driven to rotate relative to the conical shell 11. The second disk 21 is provided with a plurality of second round holes, the first disk 22 is provided with a plurality of first round holes corresponding to the second round holes one by one, and when the second disk 21 rotates relative to the first disk 22, the second round holes and the first round holes can be communicated or staggered. When the second round hole is communicated with the first round hole, the coating removing device can spray the circular and/or annular plasma through the spraying cover 14; when the second circular hole and the first circular hole are misaligned, the closing of the injection hood 14 is achieved. Because second round hole and first round hole are the cavernous structure, the hole diameter is less, and when second round hole and first round hole intercommunication, the cavernous structure can effectively prevent revealing of microwave. The drift diameter of the injection cover 14 is reduced from the top and the bottom to the middle, when the second round hole is communicated with the first round hole, linear plasmas are injected from the second round hole and the first round hole, and the linear plasmas are converged and injected in the middle due to the sudden reduction of the drift diameter of the injection cover 14, so that relatively uniform circular plasmas are formed. The conical shell 11 is provided with a third motor 23, the third motor 23 is connected with a third gear 24, the periphery of the second disk 21 is surrounded by a circle of third rack 25 meshed with the third gear 24, when the third motor 23 works, the third gear 24 connected with the third motor is driven to rotate, as the second disk 21 rotates relative to the first disk 22 and the periphery of the second disk 21 is surrounded by a circle of third rack 25 meshed with the third gear 24, the third gear 24 rotates to drive the third rack 25 meshed with the third gear to rotate, and finally the second disk 21 is driven to rotate by taking the axis of the second disk 21 as the center, so that the opening and closing of the injection cover 14 are realized. When the injection hood 14 is used, the third motor 23 is driven to communicate the second circular hole with the first circular hole; when the ejection hood 14 is closed, the third motor 23 is driven to misalign the second circular hole and the first circular hole.

The bottom of the second disc 21 is connected with a cone through threads; the top of the cone is small and the bottom is large. With the above structure, the injection cover 14 is used for injecting the circular and/or annular plasma, and when the annular plasma needs to be injected, the bottom of the second disk 21 is connected with a cone through a thread, the top of the cone is smaller and the bottom is larger, and the bottom of the cone and the side wall of the bottom of the injection cover 14 form an annular channel. When the second round hole is communicated with the first round hole, linear plasmas are jetted out from the second round hole and the first round hole, the linear plasmas are converged and jetted in the circular ring-shaped channel due to the fact that the middle of the drift diameter of the jet cover 14 is suddenly contracted and the bottom of the second circular disc 21 is connected with a cone through threads, and the linear plasmas form relatively uniform circular ring-shaped plasmas. When the circular plasma needs to be ejected, the cone can be detached from the bottom of the second disk 21.

Example four:

see figures 1-6. On the basis of the third embodiment, the method for removing the coating by using the microwave plasma adopts the device for removing the coating by using the microwave plasma, and the gas inlet pipe 3 conveys reaction gas into the plasma generating cavity; a microwave feed-in port arranged at the left end of the rectangular waveguide 1 feeds in microwaves, and plasma is excited in a plasma generating cavity; the spraying part sprays plasma to the coating to be removed to remove the coating. According to the structure, the method for removing the coating by using the microwave plasma adopts the device for removing the coating by using the microwave plasma, and specifically comprises a ventilation step, a microwave feeding step, a plasma exciting step, a deep hole coating removing step, a two-side included angle gap coating removing step and a plane coating removing step;

the ventilation step is as follows: opening a gas source, conveying the reaction gas into the plasma generation cavity through the gas inlet pipe 3, and spraying the reaction gas out of the spraying part;

the step of feeding microwaves comprises the following steps: starting a microwave source, inputting microwaves to the left end of the rectangular waveguide 1 by adopting the microwave source, transmitting the microwaves into the circular waveguide 5 after passing through the rectangular waveguide 1, the metal round table 6 and the metal pipe 7, and finally reaching the plasma generation cavity;

the step of exciting the plasma comprises the following steps: the microwave forms a high electric field in the plasma generating cavity and ionizes reaction gas to excite the plasma;

the deep hole coating removing step comprises the following steps: the injection device 2 is extended into the deep hole, and the control valve 20 is adjusted to enable the injection pipe 13 to be in a closed state; driving the third motor 23 to make the second circular hole and the first circular hole dislocated, and the injection cover 14 is in a closed state; driving a second motor 16 to enable the strip-shaped opening 12 to be in an open state, ejecting plasma from the strip-shaped opening 12 to form wide-width plasma, and ejecting plasma to the side wall of the deep hole to be coated to remove the coating; driving a first motor 8 to enable the injection device 2 to rotate, driving the strip-shaped opening 12 to rotate for 360 degrees, and quickly removing a circle of coating on the side wall of the deep hole; a mechanical arm can be arranged on the coating device, and the upper and lower action positions of the strip-shaped opening 12 are adjusted through the movement of the mechanical arm, so that the coating on the side wall of the whole deep hole can be quickly removed;

the step of removing the coating of the gap between the two included angles is as follows: driving the third motor 23 to make the second circular hole and the first circular hole dislocated, and the injection cover 14 is in a closed state; driving the second motor 16 to close the bar-shaped opening 12; adjusting the control valve 20 to open the injection pipe 13, and injecting the plasma from the injection pipe 13 to form linear plasma; aligning the jet pipe 13 to the coating of the included angle of the two surfaces to be removed, and removing the coating of the included angle of the two surfaces; the coating at the whole included angle gap is removed by moving the spray pipe 13, for example, by the movement control of a mechanical arm;

the step of removing the plane coating comprises the following steps: driving the second motor 16 to close the bar-shaped opening 12; adjusting the control valve 20 to close the injection pipe 13; the third motor 23 is driven to communicate the second circular hole with the first circular hole, the injection hood 14 is in an open state, and plasma is injected from the injection hood 14 to form circular plasma, so that the planar coating can be removed.

Example five:

see figures 1-6. On the basis of the third embodiment, the device can also be used in a low-pressure environment, and the specific working process is as follows: connecting the injection component with a vacuum pump, and starting the vacuum pump to ensure that the vacuum degree in the plasma generation cavity reaches a low-pressure environment, such as 30pa; opening a gas source, conveying the reaction gas into the plasma generation cavity through the gas inlet pipe 3, and spraying the reaction gas out of the spraying part, wherein the reaction gas is, for example, 0.3-1L/min oxygen or mixed gas of the oxygen and carbon tetrafluoride; when the vacuum degree tends to be stable, starting a microwave source, inputting microwaves to the left end of the rectangular waveguide 1 by adopting the microwave source, transmitting the microwaves into the circular waveguide 5 after passing through the rectangular waveguide 1, the metal circular table 6 and the metal pipe 7, and finally reaching the plasma generation cavity; under the low-pressure environment, the microwave forms a high electric field in the plasma generating cavity and ionizes reaction gas to excite plasma, wherein the plasma diffuses towards the outlet direction of the spraying part under the suction action of the vacuum pump and chemically reacts with the coating, and the coating is completely removed after a certain time.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims (10)

1. An apparatus for removing a coating by microwave plasma, comprising: the device comprises a rectangular waveguide (1), a conversion component, an injection device (2) and an air inlet pipe (3); the injection device (2) comprises a housing and an injection member; the microwave feeder is arranged at the left end of the rectangular waveguide (1), and the rectangular waveguide (1) is connected with the shell through a conversion component; a plasma generating cavity is arranged in the shell; the conversion component is used for transmitting the microwaves in the rectangular waveguide (1) to the plasma generation cavity; the gas inlet pipe (3) is used for conveying reaction gas into the plasma generation cavity; the shell is provided with an injection component; the injection member is used for injecting plasma.

2. A microwave plasma decoating apparatus as defined in claim 1, wherein: the right end of the rectangular waveguide (1) is provided with a metal shielding plate (4); the conversion component comprises a circular waveguide (5) and a metal circular table (6); a circular waveguide (5) is arranged on the lower surface of the rectangular waveguide (1); the bottom of the circular waveguide (5) is connected with a shell; the metal round table (6) is arranged at the top of the inner side of the rectangular waveguide (1); the air inlet pipe (3) is a metal pipe (7); an air inlet channel is arranged in the center of the metal round table (6); the top of the air inlet channel is communicated with the outside, and the bottom of the air inlet channel is connected with a metal pipe (7); the metal pipe (7) is positioned in the circular waveguide (5) and is coaxially arranged; the metal round platform (6) is used for introducing microwaves in the rectangular waveguide (1) into a space between the metal pipe (7) and the round waveguide (5).

3. A microwave plasma decoating apparatus according to claim 2, wherein: the rectangular waveguide (1) is movably connected with the circular waveguide (5); a first motor (8) is arranged on the rectangular waveguide (1), and the first motor (8) is connected with a first gear (9); a circle of first racks (10) meshed with the first gear (9) is arranged around the periphery of the circular waveguide (5); the first motor (8) is used for driving the first gear (9) to rotate, so that the first gear (9) drives the circular waveguide (5) to rotate through the first rack (10).

4. A microwave plasma decoating apparatus according to claim 1, 2 or 3, wherein: the shell is a conical shell (11); the diameter of the top of the conical shell (11) is larger than that of the bottom; the side surface of the conical shell (11) is provided with a strip-shaped opening (12) and an injection pipe (13), and the bottom of the conical shell (11) is provided with an injection cover (14); the strip-shaped opening (12) is arranged along the bus direction of the conical shell (11); the strip-shaped port (12) is used for spraying wide-width plasma; the injection pipe (13) is used for injecting linear plasma; the spraying cover (14) is used for spraying circular and/or circular plasma.

5. A microwave plasma decoating apparatus according to claim 4, wherein: the outer surface of the conical shell (11) is provided with an arc-shaped plate (15) in a matching way; a second motor (16) is arranged on the circular waveguide (5), and the second motor (16) is connected with a second gear (17); a second rack (18) meshed with the second gear (17) is arranged on the arc-shaped plate (15); the second motor (16) is used for driving the second gear (17) to rotate, so that the second gear (17) drives the arc-shaped plate (15) to rotate by taking the axis of the conical surface shell (11) as the center through the second rack (18); the arc-shaped plate (15) is used for controlling the opening and closing of the strip-shaped opening (12).

6. A microwave plasma decoating apparatus according to claim 5, wherein: a memory metal sheet (19) is arranged on one side of the arc-shaped plate (15); the memory metal sheet (19) is provided with a strip plug corresponding to the strip-shaped opening (12).

7. A microwave plasma decoating apparatus according to claim 4, wherein: and a control valve (20) is arranged on the injection pipe (13).

8. A microwave plasma decoating apparatus according to claim 4, wherein: the drift diameter of the injection cover (14) is reduced from the top and the bottom to the middle; a second disc (21) is fixed at the top of the injection cover (14); a first disc (22) is fixed at the bottom of the conical shell (11); the second disc (21) is rotatably connected with the first disc (22) and is coaxially arranged; a plurality of second round holes are arranged on the second disc (21); a plurality of first round holes which correspond to the second round holes one by one are arranged on the first disc (22); a third motor (23) is arranged on the conical shell (11), and the third motor (23) is connected with a third gear (24); the periphery of the second disk (21) is surrounded by a ring of third racks (25) meshed with a third gear (24); the third motor (23) is used for driving the third gear (24) to rotate, so that the third gear (24) drives the second disc (21) to rotate through the third rack (25); the second disk (21) rotates relative to the first disk (22) to enable the second round hole to be communicated with or dislocated with the first round hole.

9. A microwave plasma decoating apparatus according to claim 8, wherein: the bottom of the second disc (21) is connected with a cone through threads; the top of the cone is small and the bottom is large.

10. A method for removing a coating by microwave plasma is characterized by comprising the following steps: apparatus for removing coatings using a microwave plasma according to any of claims 1 to 9, the gas feed tube (3) feeding a reactive gas into the plasma-generating chamber; a microwave feed-in port arranged at the left end of the rectangular waveguide (1) feeds in microwaves, and plasma is excited in the plasma generation cavity; the spraying part sprays plasma to the coating to be removed to remove the coating.

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