Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
  • B05B7/16—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed
  • B05B7/20—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed by flame or combustion
  • B05B7/201—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed by flame or combustion downstream of the nozzle
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
  • C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
  • C23C4/129—Flame spraying

Definitions

• the invention relates to a spray gun for processing powder or wire-shaped spray materials with a burner body and a burner head, the burner body having feed devices for the spray material and for a fuel gas and an oxidation gas, and the burner head having one provided with a plurality of gas nozzle channels and at least one channel for the spray material Has nozzle part and a nozzle carrier part, which are connected to each other and - if necessary via an interchangeable connecting part - with the burner body, the nozzle carrier part at least one spraying material conveying channel connected to the corresponding channel for the spray material in the nozzle part and to the corresponding feed device in the burner body having.
• Flame-tip burners of this type for powdery spray materials are known, for example, from DE patent specification 1 646 027.
• the arrangement described there has an annular mixing chamber to which fuel gas is supplied on the one hand from a common delivery channel and into which on the other hand a plurality of oxidation gas channels open.
• the mixing chamber has a relatively large volume, as a result of which a flashback or reignition into the mixing chamber, which, as practice has shown, cannot be ruled out with such a burner, can have very serious consequences.
• the flame profile in its entirety is predetermined and cannot be adapted to individual applications.
• the object of the invention is to eliminate the above-mentioned disadvantages of the known burners and, in particular, to create a flame spray burner which has a substantially greater operational reliability, especially as far as flakes are concerned.
• the invention is also based on the object of making such a flame spray burner as simple as possible and easily adaptable to a wide variety of spraying conditions and applications by the user himself, in particular with regard to the burner output, so that optimum spraying results can be achieved.
• the nozzle carrier part has at least two injectors, each of which has a calibrated oxidizing gas inlet bore opening into a corresponding injector mixing chamber, in that the nozzle carrier part furthermore has a lateral connection to each injector mixing chamber with respect to the aforementioned oxidizing gas Has fuel gas inlet bore opening into the injector mixing chamber, which is connected to a fuel gas channel, and that the nozzle carrier part has at least two injector output channels, each of which emanate from a corresponding injector mixing chamber and which at the connection point with the nozzle part in each case at least one gas nozzle channel open.
• the oxidation gas inlet bores preferably each run in injector nozzles, it being possible for the injector nozzles to be insertable into the nozzle carrier part from the connection surface with the burner body or a connecting part.
• the nozzle carrier part preferably has at least three injector nozzles which are arranged essentially parallel to one another around a central delivery channel for the spray material.
• a fuel gas channel is provided for each injector nozzle in the nozzle carrier part and this is formed by a blind hole crossing the fuel gas inlet bore, the fuel gas inlet bore preferably extending to the outer wall of the nozzle support part and this bore being pressed outwards into it , substantially spherical closure part is completed.
• the fuel gas channel is essentially formed by an annular groove on the circumference of the nozzle support part and by the inner wall of a fastening sleeve surrounding this nozzle support part.
• the individual oxidation gas inlet bores are preferably connected to a common, ring-shaped oxidation gas channel which is embedded in the surface of the nozzle support part which forms the connection surface with the burner body or the connecting part.
• the annular oxidation gas channel is preferably surrounded by sealing elements for sealing against the fuel gas channel and against the injection material delivery channel.
• these sealing elements can be formed by a common sealing disk which is arranged in the plane of the connection surface and has openings or cutouts for the spatially separate passage of spray material, oxidation gas and, if appropriate, fuel gas.
• Each injector mixing chamber preferably has a taper in the vicinity of the injector outlet channel.
• the axes of the oxidation gas and fuel gas inlet bores intersect in the vicinity of the mouth of the oxidation gas inlet bore and enclose an angle between 30 ° and 90 ".
• the ratio of the exit velocities of the oxidation gas and the fuel gas from the corresponding inlet bores into an injector mixing chamber is, for example, between 2 and 15, preferably between 2.5 and 13.
• the exit velocity of the oxidation gas can be between 500 and 650 m / sec and the corresponding Exit velocity of the fuel gas between 50 and 200 m / sec.
• the oxidation gas pressure is preferably between 2 and 5 bar and the corresponding fuel gas pressure between 0.5 and 2.5 bar.
• the injector nozzle of the flame spray burner according to the invention preferably has an insert made of oxide-ceramic material in amorphous or crystalline form or of a hard material or hard metal, in which the oxidizing gas inlet bore extends at least in the vicinity of the outlet point. At most, the injector nozzle as a whole can be made from such a material.
• Fig. 1 shows a first embodiment of the nozzle-side part of a flame spray burner, in which the burner head in
• Fig. 3 shows a second embodiment of the nozzle-side part of a flame spray burner in a similar representation as in
• the burner according to FIGS. 1 and 2 is an autogenous powder flame spray burner with a burner body 1 and a burner head, which in turn comprises a nozzle carrier part 2 and a nozzle part 3.
• the basic shape of the cylindrical nozzle carrier part 2 is connected to a likewise cylindrical part of the burner body 1 or to a corresponding separable connecting part by a union nut 4, while a union nut 5 connects the coaxial parts 2 and 3 to one another in a similar manner.
• the burner body 1 is fed with the aid of feed devices, not shown, a mixture of a flame spray powder with a carrier gas, for example oxygen or air, which serves to promote it, and also acetylene as the fuel gas and oxygen as the oxidation gas.
• the burner body may have connection, control and shut-off devices for these gases and the wettable powder.
• a supply channel 15 indicated by dashed lines in the burner body serves for supplying the powder / carrier gas mixture to the burner head and continues in a corresponding channel 16 of the nozzle support part and a channel 17 of the nozzle part. Furthermore, the burner body or the connection part 1 has three separate feed channels, such as 13, for acetylene and three separate feed channels, such as 14, for oxygen, which are also indicated by dashed lines and run parallel to the channel 15.
• the nozzle carrier part 2 has three fuel gas channels, such as 7, which connect to the corresponding channels 13 of the burner body 1. These channels are preferably arranged at equal angular distances from one another, but other arrangements are also possible, as is one of three different numbers of the respective channels, for example two or four.
• the fuel gas channels 7 in the nozzle carrier part are designed as blind bores and each continue in a fuel gas inlet bore 8 which crosses the corresponding blind bore and opens into an injector mixing chamber 10.
• this bore 8 extends from the circumference of the part 2, for example made of brass, and is closed to the outside with the aid of a steel ball pressed into the outer section of the bore. This version represents a very favorable one from the point of view of the economic efficiency of the production as well as the operational safety Solution.
• the injector mixing chamber 10 is also connected to the oxygen supply channel 14, specifically via an oxidizing gas channel 12 and an oxidizing gas inlet bore 11, which run in an injector nozzle 60.
• the injector nozzle 60 and the injector nozzles 61, 62 corresponding to the two other separate oxidation gas channels are screwed into the nozzle carrier part and are accessible and replaceable from the connection side of the burner body.
• the injector nozzles protrude with a truncated cone-shaped part into the corresponding injector mixing chamber, such as 10, which has a cylindrical section and a substantially conical taper and merges into an injector outlet channel 20.
• the axes of the oxygen inlet bore and the acetylene inlet bore cross each other near the end face of the injector nozzle in the cylindrical section of the chamber and form an angle of approximately 90 °. According to another embodiment, this angle is between 30 ° and 90 °, the lowest value corresponding to the angle of inclination of the generatrix of the frusto-conical injector nozzle part.
• the inlet bore for oxygen in the injector nozzle is designed as a calibrated bore.
• the flow rate of this gas can thus be adjusted with the aid of the gas pressure in the feed device, and other means, such as 'flow meter', are not required for determining this flow rate.
• the exit velocity of the gases from the inlet bores to the injector mixing chamber is thus also determined by the set gas pressure and is, for example, 500 to 650 m / sec for oxygen and for Acetylene 50 to 200 m / sec.
• Exit speeds are preferably between 2 and 15, in particular between 2.5 and 13.
• the oxygen pressure is 3.0 bar and the exit speed from the injector nozzle with a calibrated bore of 0.45 mm diameter is 550 m / sec.
• An acetylene inlet bore of 1 mm in diameter at an angle of 90 ° causes a fuel gas outlet speed of 130 m / sec at a pressure of 0.7 bar.
• the delivery rate of the burner per injector is 330 1 / min.
• Replacing the injector nozzles allows the burner output to be changed. For example, an increase in the diameter of the oxygen inlet bore to 1 mm at a constant pressure of 3.0 bar, and thus an exit speed of 600 m / sec, increases the output per injector to 700 1 / min.
• the diameter range of the calibrated inlet bores which have a minimum length of 0.2 mm, is between 0.1 and 1.5 mm.
• the angle between the axes of the inlet bores is 30 ° instead of 90 °, for example, the same flow rate of the fuel gas is achieved at a pressure of 0.6 bar instead of 0.7 bar.
• the mixing of the gases proves to be optimal if the angle mentioned is at least approximately 90 °.
• the injector nozzle is designed in two parts in such a way that, at least in its mouth-side section, it has an outer jacket part made of metal and an inner part made of oxide-ceramic material or hard material or hard metal, in which the calibrated oxidation gas Entrance channel runs.
• the inner part preferably consists of ruby, quartz glass or other oxide-ceramic materials in monocrystalline or polycrystalline form.
• a number of gas nozzle channels 18 are arranged in the nozzle part 3, which have an acceleration part 19 at their mouth end and emanate from a corresponding distribution chamber 21 at their input end.
• a distribution chamber connects, for example, a group of gas nozzle channels to a single injector outlet channel. Frequently, however, all gas nozzle channels are connected to all injector outlet channels via an annular distribution chamber 21.
• FIGS. 3 and 4 The embodiment according to FIGS. 3 and 4 is constructed similarly to that of FIGS. 1 and 2 and practically identical parts are identified by the same reference numbers.
• the nozzle carrier part 22 of FIG. 3 forms two annular distribution channels 70 and 120 for the fuel gas and for the oxidation gas, respectively, via which these gases are fed to the individual separate injector mixing chambers, such as 10.
• the fuel gas inlet bores, such as 80, here extend from the respective mixing chamber to the fuel gas distribution channel 70, which is formed between an annular cutout on the circumference of the nozzle support part 22 and the inner wall of a fastening sleeve 40.
• the nozzle carrier part 22 is screwed into the fastening sleeve 40 and is sealingly connected to it by means of an O-ring 41.
• each of the injector nozzles such as 63, is inserted into a corresponding bore in the nozzle support part which starts from the annular oxidizing gas distribution channel 120. This is milled into the flat connecting surface of the nozzle support part here.
• a sealing disc 23 for example made of plastic, is arranged, which is centered by the sleeve 40 from its periphery and has a number of openings or recesses for the passage of the gases and the spray material.
• the burner body or connecting part 100 has in particular a central feed channel 15 for the spray material, which is connected to the corresponding channel 16 of the nozzle support part via an opening 231 in the sealing washer, and a feed channel 140 for oxygen as the oxidizing gas, this feed channel leading into the distribution channel 120 essentially opposite annular channel 141 opens.
• the sealing washer 23 has individual openings at the level of these two channels, but closed annular parts of the sealing washer ensure sealing in the radial direction both on the inner and on the outer circumference of these channels.
• Another channel 130 in the burner body or connecting part 100 is used to supply the fuel gas to an annular groove 131 on the circumference of the part 100, which on the one hand is open towards the sealing washer 23 and on the other hand is sealed off against the sleeve 40 by means of an O-ring 42.
• the sealing disk 23 has individual cutouts 233 on its circumference in order to allow the gas flow between 131 and 70.
• connection described is characterized by its structural simplicity and great operational reliability, even when individual parts such as the nozzle part, the nozzle support part and the connecting part are replaced at the place of use.
• the total volume of fuel gas oxidizing gas delivered is distributed over a plurality of injector mixing devices which are separate from one another. This breakdown is in case of a flashback one of the • gas paths is of great advantage, since the effect of such a setback or reignition is limited to the corresponding partial volume, which means that the risk is considerably reduced not only in terms of frequency but also in scope.
• the described arrangement of the injector nozzles in the nozzle carrier part in particular allows simple replacement thereof, either individually or together with the nozzle carrier part as a whole. This allows the burner's output to be adapted relatively easily to any specific application and, if necessary, also to change the flame profile over the circumference of the nozzle part.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• Plasma & Fusion (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Nozzles For Spraying Of Liquid Fuel (AREA)
• Nozzles (AREA)
• Oxygen, Ozone, And Oxides In General (AREA)
• Coating By Spraying Or Casting (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=4252827

Family Applications (1)

Country Status (5)

Cited By (3)

Citations (8)

• 1986
  • 1986-08-15 CH CH3292/86A patent/CH671345A5/de not_active IP Right Cessation
• 1987
  • 1987-08-14 AT AT87904833T patent/ATE68999T1/de not_active IP Right Cessation
  • 1987-08-14 WO PCT/CH1987/000099 patent/WO1988001203A1/de active IP Right Grant
  • 1987-08-14 DE DE8787904833T patent/DE3774262D1/de not_active Expired - Lifetime
  • 1987-08-14 EP EP87904833A patent/EP0277158B1/de not_active Expired - Lifetime

Patent Citations (8)

Non-Patent Citations (1)

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