US3715076A - Method and apparatus for spraying powdered thermoplastic substances - Google Patents

Method and apparatus for spraying powdered thermoplastic substances Download PDF

Info

Publication number
US3715076A
US3715076A US00136936A US3715076DA US3715076A US 3715076 A US3715076 A US 3715076A US 00136936 A US00136936 A US 00136936A US 3715076D A US3715076D A US 3715076DA US 3715076 A US3715076 A US 3715076A
Authority
US
United States
Prior art keywords
powder
nozzle
streams
cloud
heating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00136936A
Other languages
English (en)
Inventor
T Kenderi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
HAJTOMU ES FELVONOGYAR
HAJTOMU ES FELVONOQUAR
Original Assignee
HAJTOMU ES FELVONOGYAR
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by HAJTOMU ES FELVONOGYAR filed Critical HAJTOMU ES FELVONOGYAR
Application granted granted Critical
Publication of US3715076A publication Critical patent/US3715076A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • B05B7/14—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 designed for spraying particulate materials
    • B05B7/1404—Arrangements for supplying particulate material
    • 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
    • B05B7/205—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 the material to be sprayed being originally a particulate material
    • 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
    • B05B7/205—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 the material to be sprayed being originally a particulate material
    • B05B7/206—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 the material to be sprayed being originally a particulate material in a container fixed to the discharge device
    • 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
    • B05B7/22—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 electrically, magnetically or electromagnetically, e.g. by arc
    • 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
    • B05B7/22—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 electrically, magnetically or electromagnetically, e.g. by arc
    • B05B7/222—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 electrically, magnetically or electromagnetically, e.g. by arc using an arc
    • B05B7/226—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 electrically, magnetically or electromagnetically, e.g. by arc using an arc the material being originally a particulate material

Definitions

  • the metered powder is sprayed in the shape of a cone; and consequently, it is impossible to ensure the uniform heating of the powder or the uniform layer thickness of the coating.
  • the devices provided with such nozzles although suitable for purposes of backfill welding, are unsuitable for the production of a corrosion-resistant coating requiring a uniform layer thickness over a large surface area.
  • a powder spray device is also known wherein the mixing of oxygen or air and fuel gas is effected by means of nozzle bores arranged in parallelism to each other in two concentric circles.
  • a guide ring connected to the nozzle by a metal bond is employed for varying the flame shape. Due to this metallic connection, the nozzle is strongly heated during operation.
  • the powder spray nozzle is mounted by means of a fixed and airtight connection provided on the center line of the nozzle. In other words, the nozzle is surrounded on all sides by the flame during operation. Also in this apparatus, a cone-shaped spray jet results which, accordingly, does not ensure that the thus-sprayed powder particles are heated uniformly.
  • the axis of the bores serving for the exit of the gaseous mixture producing the flame is disposed parallel to the axis of the power nozzle; consequently, the lateral expansion of the powder jet is unlimited, with the result that the planar surface to be coated by means of the spray from this nozzle is provided with a non-uniform coating which is thicker in the center.
  • Still another device is conventional wherein the powder to be sprayed is conducted by the nozzle through a pipe with a heated wall and is plasticized in this manner.
  • the mouth opening of the nozzle is provided with a number of bores through which unheated gas is admixed with the hot gas jet conveying the molten powder.
  • the pipe serving for melting the powder must have a temperature which is substantially above the melting point of the powder. Thus, for example when spraying aluminum powder, this temperature is above 900 C. However, at such a high temperature, the gastight seal and the production thereof are plagued with difliculties.
  • the orifice adjoining the end of the heating pipe is fashioned with a circular cross section, or with a different one, for example a basket-shaped cross section,
  • a consequence of this shape is that the powder which has been molten or brought to a high degree of plasticity is subjected, after flowing through the round heating pipe, to a forcible change in direction in the basket-shaped mouth orifice; and as a result, the powdered substance adheres to the wall of the mouth orifice.
  • An object of the present invention is to provide a process and construction of a powder spraying apparatus universally suitable for powder types having a high melting point as well as those having a low melting point, without exhibiting the disadvantages of the above-described devices, and ensuring a uniform and reliable heating of the powder, as well as, after shutoff and resumption of operation, a uniform metering of the powder and a uniform thickness of the coating, without the use of additional energy, and capable of being cleaned easily without disassembly.
  • the invention resides in that the powdered substance to be sprayed is spread out in a cold condition, with the aid of a cold gaseous stream, in the form of a flat cloud, the thickness of which cloud must be at least twice the granular size of the powder to be sprayed and at most one-eighth inch, the application of the powder to the substrate to be coated being effected by means of the cloud laterally supported by a gaseous stream and shaped as set out above, with simultaneous melting by thermal or electric energy.
  • this invention is based on the surprising finding that a cloud-like powder stream spread out flat can be heated in quite a short period of time and without the aid of any larger amount of thermal energy, over its entire extent, i.e., from the exit of the powder particles from the discharge orifice of the nozzle until their im pingement on the substrate to be coated, to the desired extent.
  • the cloud-like powder jet spread out flat is heated over its entire extent.
  • the invention provides not only an apparatus suitable for conducting the process of this invention, equipped with a powder container with a metering unit, but also a spraying device suitable for spraying the metered powder.
  • the spraying device is provided with a flat or fishtail nozzle, the width of which is at least twice the granular size of the powder to be sprayed and which nozzle is provided with a flat outlet orifice of a length of at most ten inches.
  • gasconducting bores are arranged on both sides of this outlet orifice and form an angle of about 20 with the midplane or plane of symmetry of the spraying device.
  • energy supply elements are provided behind the outlet orifice of the nozzle, which elements extend along the two longitudinal sides of the powder jet spread out by means of the nozzle and defined laterally by gas jets.
  • This construction of the spraying device ensures cooling of the nozzle, since the air sucked in through an opening between the heating head and the nozzle ensures intense cooling due to the injector effect of the powder stream emanating from the spray nozzle.
  • this structural design also results in a quieter flow of the flame jets, because with the sunken nozzle construction the marginal vortex produced by the exit of the powder stream does not reach the flame jets.
  • the inlet opening of the ejector serving for conveying the powder is arranged on the side of the ejector suction chamber.
  • a metering unit is provided which is controlled independently of the ejector, which unit is positively mechanically operated and is provided with an infinitely variable control.
  • this metering device can be operated independently of the ejector at any time with the required amount of power, or the operation can be interrupted or started up again. Due to the fact that this metering unit is provided with an electrically driven vibrating chute, bridging over of the powdered substance is avoided by transmitting vibrations to the system.
  • the spraying of the required amount of powder can be conducted with safety; and an additional advantage is afforded by the fact that all powder particles can be heated to the same temperature and that the device is universal, i.e. it is suitable for the spraying of powders of a high melting point, as well as those of a low melting point.
  • FIG. 1 diagrammatically shows the arrangement of the metering unit of the powder spraying device according to the present invention
  • FIG. 2 is a fragmentary sectional view of the ejector of the device
  • FIG. 3 diagrammatically shows the arrangement of the nozzle of the spraying device according to this invention
  • FIG. 4 is a horizontal sectional view of FIG. 3;
  • FIG. 5 is a view of the nozzle of this invention as a heater outlet orifice according to a modification of the apparatus.
  • FIG. 6 is a horizontal sectional view of the embodiment illustrated in FIG. 5.
  • Container 1 for the storage of the powder to be sprayed.
  • Container 1 is open so that the powder can be replenished continuously and in a simple manner.
  • container 1 is fashioned, in the illustrated embodiment, in the form of a funnel which tapers downwardly and is open at the bottom.
  • the powdered substance to be meterd flows through the lower end of this hopper to the vibrating chute 2.
  • the vibrating chute 2 is actuated by an electromagnet.
  • the feed of the powder present in container 1 can be infinitely varied by means of a rheostat (not shown) independently of the quantity of powder present. By interrupting the current source for the magnet, the powder feed can be interrupted or started up again at any desired instant, or it can be continued for any desired length of time. Underneath the discharge end of the vibrating chute 2, a funnel 3 is provided.
  • an opening 4 is provided which is in communication with the ejector 5, which latter is constantly operated.
  • the powder dropping from the vibrating chute 2 thus passes through the funnel 3 and the opening 4 thereof into the ejector 5, which latter then entrains the powder and feeds the same to the nozzle via the conduit 6.
  • the spraying head essentially consists of the flat fishtail nozzle 7 and the heater 8, wherein the nozzle 7 is disposed in the longitudinal gap of the heater 8.
  • the powder conveyed through the conduit 6 is transformed, by the nozzle 7, into a finely distributed, cloud-like stream 9 and blown through the heater 8 between the two rows of flames 10 arranged on the right-hand and left-hand sides of the burner '8 as seen in FIG. 4.
  • the oxygen or air required for combustion, as well as the fuel-gas mixture are fed to the burner 8 via the conduit l l.
  • the latter is independent of the heater 8 and is connected to the heater in a suitable manner by heat insulation. In place of heat insulation, it is also possible to provide cooling at this point.
  • the outlet opening of the nozzle 7 is not disposed flush with the front of the heater "8 but rather is somewhat farther to the rear at a distance therefrom.
  • air is sucked in through the gap between the heater 8 and the nozzle and thereby a significant cooling effect is obtained. Due to this construction of the spray head, the flow of the flame jets of the row 10 of flames is also quieter and more uniform since this flow is not aifected by the marginal vortex of the emerging powder jet.
  • the nozzle 7 is flat, and the width of its orifice is at least twice the diameter of the powder grains to be sprayed, whereas this width must be no larger than It has been found in practice that the length of the mouth orifice of the nozzle 7 must not exceed ten inches.
  • outlets of the row 10 of flames on the right-hand and left-hand sides of the burner '8 are disposed at a maximum spacing of 0.4 inch as measured from the edge of the nozzle 7 in the lateral direction.
  • the center. line of each outlet of the row 10 of flames forms an angle of at least 5 and at most 20 with the flow direction of the powder jet 9.
  • the outlet orifice of the nozzle 7 is spaced about 0.040.3 inch behind the front of the burner 8.
  • the powder container 1 is filled with the powder to be sprayed; thereafter, with the aid of the rheostat (not shown), the amount to be fed is set, and in correspondence therewith, the vibrating chute Zexecutes a shaking motion and thereby conveys the powdered substance from the container 1 along the vibrating chute 2 to the funnel 3 of the ejector 5.
  • the ejector 5 is in continuous operation, whereas the metering of the powder can be interrupted and/or started up again at any desired instant by switching the magnet of the vibrating chute 2 on or 011.
  • the opening 4 on the side of the funnel is arranged laterally in the ejector 5, it is impossible for clogging to occur by shutting ofi or erroneous operation of the device, for the suction chamber thus cannot be clogged.
  • the powdered substance passes via conduit 6 into the nozzle 7; the latter then conveys the powder through its flat opening in the form of a cloud-like, finely distributed powder jet 9, into the space between the rows 10 of flames of the heater 8. During this process, the powder jet 9 is sandwiched between the flame rows 10. The gaseous stream emanating between the flame rows 10 of the heater 8 heats the powdered substance to be sprayed.
  • the heater -8 of this invention ensures such a surprisingly high degree of thermal efficiency that it is possible to spray not only synthetic resin powders, but, with the use of a gas-air mixture, also powdered aluminum.
  • the gas pressure relationships can also be selected so that the heater 8 remains untouched by the flame core and thus the burner is kept completely cold during operation and even cools the exiting gaseous stream. Accordingly, it is also possible to avoid any adherence of the powder, and to ensure the spraying thereof without combustion, with safety, without the use of any special measures.
  • An additional advantage resides in that the heating of the cold powder flowing out of the cold nozzle 7 begins in the mixing zone of the combustion gas mixture and the powder jet 9, at a distance of about 0.3-0.4 inch from the front of the heater 8, in the free space or between surfaces serving for heating purposes; consequently, strongly adhering powders such as, for example, powdered synthetic resins, do not adhere anywhere nor produce disturbances in operation.
  • the heater 8 provided for ensuring the lateral expansion of the powder jet 9 can also be entirely omitted in certain cases, in which case the powder jet 9 exiting from the nozzle 7 is then immediately supplied with the required thermal or electric energy by the energy supply elements 12.
  • a method for spraying powdered thermoplastic substances onto a solid substrate comprising entraining the powdered substance in a cold gaseous stream, projecting said stream from an outlet opening in the form of a flat cloud against a said substrate, projecting a pair of gaseous streams from outlet openings that are on opposite sides of and forward of the first-mentioned outlet opening, laterally confining the projected stream between said pair of gaseous streams, sucking air between said pair of gaseous streams from behind and on opposite sides of said first-mentioned outlet opening, and applying heat to opposite sides of said fiat cloud while confined between said pair of streams.
  • Apparatus for spraying powdered thermoplastic substances onto a solid substrate comprising a spray nozzle having an elongated flat outlet opening, means to feed to said nozzle and out said outlet opening a stream of powdered thermoplastic substance in the form of a flat cloud of particles entrained in a relatively cold gas, means to direct streams of gas from opposite sides through further outlet openings at an acute angle against opposite sides of the flat cloud of particles emerging from said nozzle thereby to confine said flat cloud between said streams, said outlet opening of said nozzle being to the rear of said further outlet openings, means to suck air forwardly between said further outlet openings and on opposite sides of said nozzle outlet opening, and means to heat said fiat cloud between said streams.
  • said heating means comprising a burner from which :said streams emerge as flames.
  • said heating means comprising a pair of heating elements between which said cloud passes between said nozzle and said substrate.
  • said feed means including an ejector having an inlet opening for powdered substance horizontally to the side of the ejector thereby to avoid clogging of the ejector with said powdered substance.
  • said feed means comprising a vibratory conveyor feeding to a hopper which in turn feeds to an ejector by which said particles are entrained in a gas stream.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Nozzles (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
US00136936A 1971-04-23 1971-04-23 Method and apparatus for spraying powdered thermoplastic substances Expired - Lifetime US3715076A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US13693671A 1971-04-23 1971-04-23

Publications (1)

Publication Number Publication Date
US3715076A true US3715076A (en) 1973-02-06

Family

ID=22475086

Family Applications (1)

Application Number Title Priority Date Filing Date
US00136936A Expired - Lifetime US3715076A (en) 1971-04-23 1971-04-23 Method and apparatus for spraying powdered thermoplastic substances

Country Status (4)

Country Link
US (1) US3715076A (fr)
BE (1) BE765071A (fr)
CH (1) CH556691A (fr)
FR (1) FR2130989A5 (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3958758A (en) * 1975-05-27 1976-05-25 Owens-Illinois, Inc. Spraying apparatus
US4289807A (en) * 1980-03-03 1981-09-15 The Dow Chemical Company Fusion processing of synthetic thermoplastic resinous materials
EP0074678A1 (fr) * 1981-09-10 1983-03-23 Talmer BV Méthode pour le remplissage d'un mur creux avec du matériau fibreux d'isolation, en particulier des fibres de verre
US4396651A (en) * 1977-12-27 1983-08-02 Vianova Kunstharz, A.G. Process for spraying water-dilutable paint systems
US4551191A (en) * 1984-06-29 1985-11-05 The Procter & Gamble Company Method for uniformly distributing discrete particles on a moving porous web
US4616779A (en) * 1983-08-08 1986-10-14 Societe Nationale Industrielle Aerospatiale Process and device for injecting a finely divided material into a hot gaseous flow and apparatus for carrying out this process
US5134959A (en) * 1989-06-19 1992-08-04 General Electric Company Apparatus for coating fibers with thermoplastics
US6086813A (en) * 1997-09-23 2000-07-11 Brunswick Corporation Method for making self-supporting thermoplastic structures
US20080060574A1 (en) * 2006-09-13 2008-03-13 Xiom Corporation Powder coating spraying device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5646853Y2 (fr) * 1977-11-15 1981-11-02

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3958758A (en) * 1975-05-27 1976-05-25 Owens-Illinois, Inc. Spraying apparatus
US4396651A (en) * 1977-12-27 1983-08-02 Vianova Kunstharz, A.G. Process for spraying water-dilutable paint systems
US4289807A (en) * 1980-03-03 1981-09-15 The Dow Chemical Company Fusion processing of synthetic thermoplastic resinous materials
EP0074678A1 (fr) * 1981-09-10 1983-03-23 Talmer BV Méthode pour le remplissage d'un mur creux avec du matériau fibreux d'isolation, en particulier des fibres de verre
US4616779A (en) * 1983-08-08 1986-10-14 Societe Nationale Industrielle Aerospatiale Process and device for injecting a finely divided material into a hot gaseous flow and apparatus for carrying out this process
US4551191A (en) * 1984-06-29 1985-11-05 The Procter & Gamble Company Method for uniformly distributing discrete particles on a moving porous web
US5134959A (en) * 1989-06-19 1992-08-04 General Electric Company Apparatus for coating fibers with thermoplastics
US6086813A (en) * 1997-09-23 2000-07-11 Brunswick Corporation Method for making self-supporting thermoplastic structures
US20080060574A1 (en) * 2006-09-13 2008-03-13 Xiom Corporation Powder coating spraying device
WO2008033458A3 (fr) * 2006-09-13 2008-06-05 Xiom Corp Dispositif de pulverisation de revetement en poudre

Also Published As

Publication number Publication date
CH556691A (de) 1974-12-13
FR2130989A5 (fr) 1972-11-10
BE765071A (fr) 1971-08-16

Similar Documents

Publication Publication Date Title
US2961335A (en) Method and apparatus for applying heat-fusible coatings on solid objects
US2920001A (en) Jet flame spraying method and apparatus
US3715076A (en) Method and apparatus for spraying powdered thermoplastic substances
EP0049915B1 (fr) Procédé et dispositif pour la pulvérisation au jet de flamme supersonique avec une matière concentrée en fusion
US2317173A (en) Apparatus for melting powdered materials
US3817503A (en) Apparatus for making metal powder
EP0361710A1 (fr) Dispositif pour la pulvérisation thermique à grande vitesse
JPH02503068A (ja) 粉末噴霧装置
CA1190391A (fr) Dispositif de chargement a la flamme avec organe d'acceleration
EP0136978A3 (fr) Procédé et appareil de pulvérisation supersonique à flamme pour des matériaux de haute concentration
WO1989002318A1 (fr) Pistolet vaporisateur de poudre
US1128175A (en) Method of producing bodies or small particles of substances.
JPH0710360B2 (ja) 粉体スプレ−装置及び方法
EP0158468B1 (fr) Dispositif et procédé de revêtement du verre
GB1593443A (en) Intermittent spraying of powder
US3159348A (en) Apparatus for spraying heat fusible pulverulent material
JPH0674156B2 (ja) 高温ガラスに金属あるいは金属化合物、特に金属酸化物を被覆する方法
US4533571A (en) Method and apparatus for uniformly coating a substrate with a powder
US5358221A (en) Block assembly for use in metal scarfing apparatus
US3453134A (en) Electrostatic pipe coating method and apparatus
US4836448A (en) Thermal spray gun with fan spray
US2754234A (en) Thermochemical metal removal
JPS6141707A (ja) 粉末金属製造装置
CN216378348U (zh) 一种热喷涂设备
GB1003118A (en) Method of fusing atomizing and spraying a refractory oxide