Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B3/00—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements
  • B05B3/02—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements with rotating elements
  • B05B3/04—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements with rotating elements driven by the liquid or other fluent material discharged, e.g. the liquid actuating a motor before passing to the outlet
  • B05B3/06—Spraying or sprinkling apparatus with moving outlet elements or moving deflecting elements with rotating elements driven by the liquid or other fluent material discharged, e.g. the liquid actuating a motor before passing to the outlet by jet reaction
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
  • B08B3/02—Cleaning by the force of jets or sprays
  • B08B3/024—Cleaning by means of spray elements moving over the surface to be cleaned
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B44—DECORATIVE ARTS
  • B44D—PAINTING OR ARTISTIC DRAWING, NOT OTHERWISE PROVIDED FOR; PRESERVING PAINTINGS; SURFACE TREATMENT TO OBTAIN SPECIAL ARTISTIC SURFACE EFFECTS OR FINISHES
  • B44D3/00—Accessories or implements for use in connection with painting or artistic drawing, not otherwise provided for; Methods or devices for colour determination, selection, or synthesis, e.g. use of colour tables
  • B44D3/16—Implements or apparatus for removing dry paint from surfaces, e.g. by scraping, by burning

Definitions

• the invention relates to a device of the type specified in the preamble of claim 1.
• solvents are usually used that dissolve the paint or cause it to swell. The paint is then removed by mechanical treatment.
• the use of solvents leads to a great environmental impact.
• the chromates that mix with the solvent are difficult to remove from the solvent.
• a significant proportion of the solvent evaporates into the atmosphere.
• abrasive materials can be plastic granules, glass balls, nutshell splinters or C0 2 ice crystals.
• Such abrasive processes have the disadvantage that not only the paint is removed, but also the underlying surface is damaged. In particular if this surface is made of fiber-reinforced plastic, there is a risk that the reinforcing fibers will be exposed by irradiation with abrasives, so that the surface to be stripped will be seriously damaged.
• the invention has for its object to provide a device for en varnishing painted surfaces, in which the environmental pollution is reduced to a minimum and which enables a surface-friendly stripping.
• the device according to the invention contains a rotor head with at least one nozzle from which a liquid jet emerges at high pressure.
• the rotor head is set in rotation by the pressure of the liquid jet or by its recoil, so that a separate rotating device on the housing is not necessary. Due to the rotation of the rotor head and the nozzles arranged thereon, the individual points on the surface are periodically pressurized from approximately 150 to 220 Hz. As a result of the swelling up and down This pressure load overcomes the cohesive pressure of the paint and the paint splinters off the surface. This means that both the top coat and the primer can be removed.
• the rotor head is located inside the housing, the opening of which is closed by the surface to be treated. The housing thus completely encloses the treatment room.
• the closed housing prevents liquid from being thrown into the environment in an uncontrolled manner. Noise pollution is also reduced.
• the liquid and the paint materials detached from the surface are removed from the housing by the impeller.
• the impeller forms a centrifugal pump arranged inside the housing, which does not obstruct the jet emerging from the nozzle and removes the suspension from the housing immediately after it is created. This ensures that the liquid jets are not obstructed by a liquid layer on the surface.
• the device according to the invention only requires a connection for pressure fluid on the housing and no additional drives or supply lines.
• the device is therefore easy to move over the surface to be treated.
• the device is particularly suitable for stripping surfaces which consist of metal or plastic. It can be used to paint the outer skin of aircraft. Aircraft are stripped and repainted every four to six years. This stripping takes place in a hall in which other maintenance or repair work is carried out on the aircraft.
• the device can be used in a manner which is gentle on the environment without obstruction or danger to persons who are entrusted with other work on the aircraft, it being only locally effective at the point at which it is used. The splashing around of liquid and noise pollution are avoided.
• the outer skin of aircraft consists of aluminum alloys and partly of carbon fiber composite materials. Both types of material can be stripped with the same device.
• the use of the device according to the invention is not limited to the stripping of aircraft surfaces. Any other surface can also be freed from lacquer or corresponding coatings. With a correspondingly small-sized design, it is also possible to use the device for stripping fingernails.
• the paint stripping is carried out by pulsing periodic pressurization with a liquid jet. Solvent-free liquids can be used. Stripping is preferably carried out with water. The removal of the water-insoluble color particles from the water can be carried out by sedimentation or other separation processes, so that no contaminated water gets into nature. If necessary, the dyes can be reused.
• the impeller rotating together with the rotor head which rotates at several thousand revolutions per minute, throws the suspension out of the housing to the outlet.
• Requirement for this function of the The impeller is that the impeller or the rotor head is not braked by a liquid accumulation in the housing. If the stripping device has to be operated in different positions, for example on horizontal surfaces, vertical or inclined surfaces and overhead, liquid accumulations in each of these positions can be prevented by the impeller at the end facing the opening the rotor head is arranged.
• the impeller is therefore effective in the immediate vicinity of the surface to be treated, along which the leading edges of its blades move. This ensures that the liquid is grasped by the impeller immediately after it hits the surface and is thrown off radially, so that no liquid accumulations can form which impede the rotation of the impeller and the rotor head.
• Fig. 1 shows an axial section through an embodiment of the paint stripping device
• Fig. 2 is a view of the paint stripping device from below.
• the stripping device has a housing 10 which is designed in the manner of a bell and has an opening 11, the edge of which is attached to the surface 12 to be stripped. If the housing 10 is attached to the surface 12, its interior 13 is completely shielded from the outside, although one Ventilation device is provided, which will be explained later.
• a shaft 14 is fastened, which has a liquid connection 15.
• the shaft 14 is fixedly mounted in a socket 16 of the housing 10.
• An axis 17 is screwed into the shaft 14, which extends from the shaft 14 into the vicinity of the opening 11 and on which the rotor head 18 is rotatably mounted.
• the rotor head 18 contains two nozzles 19, 20, the openings 21 of which exit vertically on a frustoconical surface 22.
• the frustoconical surface 22 is arranged to the surface 12 or to the plane of the opening 11 at such an angle that the jets emerging from the nozzle openings 21 strike the surface 12 at an angle different from 90 ", for example at an angle of 60" . This means that the axes of the nozzles 19 and 20 form an angle of 30 ° with the axis of the shaft 17.
• the rotor head 18 contains a longitudinal bore 23 which receives the shaft 17.
• a channel 24 in the interior of the shaft 17 is connected to the liquid connection 15 and from this channel cross bores 25 lead to an annular groove 26 in the rotor head 18.
• a bore 27 leads from this annular groove 26 to the respective nozzle 19 or 20.
• the surface of the shaft 17 is provided with a ceramic coating 17a, which on the one hand forms a sliding bearing for the rotor head 18 and on the other hand seals the bore 23.
• 26 sealing grooves 29 are provided in the bore 23 on both sides of the annular groove.
• the impeller 30 is fastened with screws 31 on the end face of the rotor head 18 facing the opening 11.
• the impeller 30 has a plurality of essentially radial vanes 32 which are fastened to a sleeve 33.
• the collar 33 is frustoconical in shape corresponding to the surface 22, so that it has a plate-like shape and its distance from the surface 12 increases radially outwards.
• the leading edges 34 of the blades run radially to the axis of the rotor head 18 and in a plane which is directed parallel to the plane of the opening 11.
• the rotor head 18 is supported on a flange 35 of the fixed shaft 17 and at the front end on a disk 36 which is fastened with a screw 37 at the front end of the shaft 17.
• the nozzles 19 and 20 are arranged on the rotor head 18 in such a way that the recoil of the liquid jet emerging from the nozzle opening 21 rotates the rotor head 18. This is achieved in that the jets emerging from the two nozzle openings 21 do not lie in a common plane but in two planes which are opposite to a plane passing through the axis of the rotor head on one side and on the opposite side a small amount are offset. This slight offset of the two nozzles, which is barely perceptible to the naked eye, means that the nozzles open out of the nozzle openings. 21 exiting liquid jets 39 give the rotor head 18 a rotation.
• the vanes 32 of the impeller 30 extend in a radial expansion of the housing 10 into it. This extension is limited by a cylindrical peripheral wall 40.
• the peripheral wall 40 is surrounded by an axially displaceable jacket 41, which is delimited at the front end by an inwardly projecting ring 42.
• the ring 42 which forms the opening 11, contains a circumferential groove 43 behind this opening for collecting liquid running off the surface 12.
• the rear end of the jacket 41 is connected to the rear end of the peripheral wall 40 via a plurality of rubber-elastic tabs 44 which are arranged in a distributed manner.
• the tabs 44 endeavor to advance the jacket 41 in the direction of the surface 12.
• the ring 42 first comes against this surface, while the peripheral wall 40 is still at a distance from it.
• the remaining part of the housing 10 is then pushed forward in the casing 41 until the front end of the peripheral wall 40 abuts the ring 42.
• Openings 46, 47 are provided at one point in the peripheral wall 40 and the casing 41, at which an outlet 48 leading tangentially out of the housing 10 is arranged. Furthermore, on the housing 10 there is a ventilation device, which in the present exemplary embodiment consists of the gap 49 between the peripheral wall 40 and the casing 41, the interior of the housing stands above this annular gap 49, which surrounds the impeller 30 in connection with the environment.
• the passage cross section of the gap 49 is approximately two thirds of the cross section of the outlet 48. Outside air is sucked in through the gap 49 and mixes with the liquid in the interior of the device, the resulting liquid-air mixture being discharged through the outlet 48. It is necessary to ventilate the inside of the housing so that the impeller in the housing does not create too great a vacuum.
• the negative pressure created in the housing is sufficient to suck the housing firmly onto the surface 12, so that no or only a small contact pressure has to be exerted on the housing.
• the device described works as follows:
• the housing 10 is attached with the opening 11 to the surface 12 to be removed.
• liquid with a high pressure of several 100 bar, e.g. 400 bar, laid.
• Liquid jets emerge from the nozzle openings 21 at high speed.
• the rotor head 18 is set in rotation by the recoil of the emerging liquid. The speed is about 4500 to 6000 U / min with two nozzles.
• the liquid jets emerging from the rotor head 18 strike the surface 12 at an angle, so that they are not hindered by the reflected liquid. If the housing 10 is held stationary, then every point on the surface 12 hit by a liquid jet is subjected to a frequency of 150 to 200 Hz. This removes the paint from this point.
• the impeller 30 attached to it rotates together with the rotor head 18.
• the liquid jets are not obstructed by this impeller because they each emerge between two vanes 32.
• the of the upper Surface 12 of the reflected liquid and the liquid running off this surface and reaching into the groove 43 or channel are flung radially by the rotating impeller 30 in the manner of a centrifugal pump and pressed to the outlet 48.
• the removal of the liquid is supported by the suction of outside air through the gap 49.
• the sucked-in outside air forms a flow in the interior of the housing, which entrains all the liquid to the outlet 48. Since the vanes of the impeller rotate in the immediate vicinity of the surface 12, the liquid is removed immediately after the decay of the liquid pressure jets, so that no liquid collections can form in the housing which would impede the rotation of the rotor head.

Landscapes

• Nozzles (AREA)
• Testing And Monitoring For Control Systems (AREA)
• Centrifugal Separators (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6419819

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (24)

Citations (7)

Family Cites Families (7)

• 1990
  • 1990-12-07 DE DE4039092A patent/DE4039092C1/de not_active Expired - Lifetime
• 1991
  • 1991-11-09 CA CA002074491A patent/CA2074491A1/en not_active Abandoned
  • 1991-11-09 AT AT91919142T patent/ATE121320T1/de not_active IP Right Cessation
  • 1991-11-09 EP EP91919142A patent/EP0506929B1/de not_active Expired - Lifetime
  • 1991-11-09 US US07/862,747 patent/US5321869A/en not_active Expired - Fee Related
  • 1991-11-09 WO PCT/EP1991/002126 patent/WO1992010313A1/de not_active Ceased
  • 1991-11-09 JP JP3517374A patent/JPH05503049A/ja active Pending

Patent Citations (7)

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