EP0163776A2 - Procédé de pulvérisation à flamme supersonique de grande concentration et appareil à alimentation améliorée - Google Patents

Procédé de pulvérisation à flamme supersonique de grande concentration et appareil à alimentation améliorée Download PDF

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Publication number
EP0163776A2
EP0163776A2 EP84116416A EP84116416A EP0163776A2 EP 0163776 A2 EP0163776 A2 EP 0163776A2 EP 84116416 A EP84116416 A EP 84116416A EP 84116416 A EP84116416 A EP 84116416A EP 0163776 A2 EP0163776 A2 EP 0163776A2
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EP
European Patent Office
Prior art keywords
nozzle
bore
combustion
expansion
extended length
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.)
Withdrawn
Application number
EP84116416A
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German (de)
English (en)
Other versions
EP0163776A3 (fr
Inventor
James A. Browning
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Individual
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Individual
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Publication date
Application filed by Individual filed Critical Individual
Publication of EP0163776A2 publication Critical patent/EP0163776A2/fr
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    • 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
    • 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

  • This invention relates to supersonic molten metal or ceramic spraying systems or sand blast systems, and more particularly, to an improved low pressure material feed to the products of combustion from an internal burner after substantial expansion at the upstream end of a nozzle of extended length for concentrated stream spraying onto a substrate downstream of the nozzle.
  • the combustion products are directed as a converging stream into the converging portion and upstream of the throat of the extended length nozzle and the solid rod or solid particle material is introduced axially into the converging stream at or upstream of the converging inlet leading to the restricted diameter throat of of the nozzle bore itself.
  • the major gas expansion through the nozzle to the atmosphere takes place after introducing the spray material to the hot combustion product gases.
  • the solid material is introduced at the point where the pressure of the products of combustion is at a maximum.
  • This in turn, requires particularly for solid particle form material, the necessity to employ relatively high pressures to force a stream of such particles into the flow stream of the products of combustion passing through the nozzle.
  • the diameter of the nozzle of extended length is required to be maintained relatively small and this restriction in the nozzle diameter increases the possibility of liquified spray material contaminating the nozzle wall and ultimately blocking the nozzle passage.
  • Flame spray apparatus of this type have also evolved for the specific purpose of causing solid particles such as sand, grit and the like to reach supersonic velocities without melting as a confined, small diameter stream, thereby permitting the particle stream to function as a sand blast stream and abrade the surface of an object placed in the path of the high velocity particles.
  • the present invention constitutes a flame spraying method involving the steps of:
  • Combustion is effected under sufficiently high pressure such that expansion well above the critical expansion is provided within an expansion duct prior to the introduction of the material to the gaseous flow.
  • the material is introduced radially or axially to the high velocity combustion product hot gas stream at the intersection of the nozzle expansion duct and the extended length nozzle bore.
  • the invention is directed to a highly concentrated supersonic material flame spray apparatus which comprises a spray gun body having a high pressure, essentially closed, internal burner combustion chamber and involving means for continuously flowing an oxy-fuel mixture under high pressure through the combustion chamber for ignition within the chamber.
  • An extended length nozzle opens to one end of the combustion chamber for permitting the products of combustion to discharge therethrough with the nozzle including a converging inlet leading to a reduced diameter throat, an expanding duct downstream of the throat, and an extended length outlet bore portion, with the bore portion having a length which is at least five times the diameter of the nozzle throat.
  • Means are required for introducing material in solid form outside of the combustion chamber into the hot combustion gases for subsequent heat softening or melting and acceleration.
  • the improvement resides in such means introducing the material within the expansion duct at a point where greater than critical pressure drop exists for the flow of the products of combustion to facilitate such introduction of the material and permit use of a relatively large nozzle outlet bore diameter to assure against particle build up of material introduced to the flow of the products of combustion on the surface of the bore and possible clogging of the nozzle prior to particle impact on a substrate downstream of the discharge end of the nozzle bore or abrasion of the nozzle bore wall during passage therethrough.
  • Such introducing means may take the form of at least one radial passage within the nozzle in the vicinity of the junction between the expansion duct and the extended length nozzle outlet bore portion downstream thereof.
  • the combustion chamber terminates in a plug having a conical projection positioned within the bore of the nozzle, with the periphery of the conical projection spaced from the nozzle bore to define with the upstream end of the nozzle bore the throat and the expansion duct, and wherein the plug includes an axial bore therein opening to the outlet bore portion.
  • Means are provided for supplying a metal or ceramic powder or abrasion particles under relatively low pressure to the axial bore within the conical projection for discharge into the nozzle outlet bore portion.
  • the apparatus 1 which may constitute a flame spray "gun" for spraying liquified metal or ceramic, is comprised of a spray torch body 10 defining an internal burner combustion chamber 11 formed by opposed end walls lOa, lOb at opposite ends of a cylindrical center section lOc and integrated thereto.
  • End wall lOb carries a extended length venturi type nozzle indicated generally at 7, including a diminished throat area 14 and supersonic expansion duct or passage 15 leading to an extended length nozzle passage or bore 16, also defined as a nozzle outlet bore portion of constant and relatively large diameter.
  • Fuel and oxidizer are supplied to the combustion chamber 11 as indicated by arrows 8 and 9 respectively via fuel supply tube 13 and oxygen supply tube 12.
  • the tubes 12 and 13 terminate at end wall lOa, and the fuel and oxygen enters the combustion chamber 11 via small diameter drilled passages 5 and 6, respectively which are angled with respect to each other so that the flows intersect.
  • the fuel and oxygen as at 8 and 9 are supplied under relatively high pressure.
  • the fuel which may be in liquid or gaseous form, forms with the oxygen a fuel/air mixture.
  • Continuous burning of a continuous flowing oxy-fuel mixture to the combustion chamber 11 is effected within the combustion chamber by ignition means such as a spark plug (not shown) with burning being initiated at the point of delivery of the fuel and air, that is, near end wall lOa and proceeding towards the opposite end wall lOb.
  • ignition means such as a spark plug (not shown) with burning being initiated at the point of delivery of the fuel and air, that is, near end wall lOa and proceeding towards the opposite end wall lOb.
  • the hot products of combustion reach sonic velocity in dicharging through the narrow throat section 14 of the venturi form nozzle 7, provided a greater than critical pressure drop exists. Further expansion of the products of combustion occurs in expansion duct or passage 15, creating a supersonic flow of the products of combustion at this point within the extended length nozzle 7.
  • the velocity of this flow at the entrance 16a to the extended length nozzle passage or bore 16 is determined by the remaining pressure drop available and the degree of expansion provided by the expanding duct 15. For example, for a chamber 11 pressure of 250 psig, the throat pressure of the hot gas flow is about 130 psig. A pressure ratio of over 9 to 1 still remains prior to discharge to the atmosphere at the discharge or exit end 16b of the extended length nozzle bore 16.
  • the overall expansion ratios are determined by the combustion chamber pressures used and the desired exit diameter of the flame jet from the nozzle extended length passage defined by bore 16.
  • the present invention is directed to the introduction of powder, in this embodiment, radially into the supersonic gas flow after considerable gas expansion and after reaching the gas flow supersonic velocity at a point where powder (or solid material in rod form) is heated, melted and accelerated by the gas passing through the extended length bore 16 and extending to the workpiece or substrate 20 upon which a deposite of particles 19 is formed.
  • a metallic powder or ceramic powder 4 or a mass of abrasion particles such as sand is supplied via tube 17 to nozzle 7 at the end of the expansion duct 15 where the constant diameter bore 16 initiates.
  • a small diameter radial hole 3 in the nozzle 7 is aligned with the end of the tube 17 so that the powder particles 18 are introduced into the gas stream G emanating from the venturi portion of the extended length nozzle 7.
  • the particles 18 are aspirated into the stream G, and are carried thereby at supersonic velocity for melting prior to impact directly against the substrate or workpiece 20 to form deposit 19.
  • a major advantage of adding the spray material 18 within the supersonic section of the nozzle 7 is that this extended length section 16 has a diameter much greater than that achieved in the past, as exemplified by my prior U. S. patent 4,416,421 for the same flow rates and pressure of the reactants.
  • the nozzle throat diameter was commonly 5/16 inch. With this diameter, the powder is spaced from the wall (upon entry) less than 1/8 of an inch from a 1/6 inch injector hole.
  • the diameter of the nozzle bore 16 increases threefold and with the powder spacing from the wall increasing to 3/8 of an inch. As may be appreciated, it is much more difficult for the powder to reach the wall of the extended length bore 16, melt and interfere with proper operation of unit, and under the most adverse conditions, accumulate if molten or near molten on the bore wall to the degree where the bore is completely clogged.
  • a second advantage of creating a major expansion of the hot gases exhausting from the internal burner, prior to injecting the spray material into the hot gas flow stream, is that the region into which the material is injected is at a much reduced pressure.
  • conventional low-pressure powder hoppers may be employed for supplying powder 4 via tube 17 to the extended length nozzle portion 16.
  • the prior apparatus exemplified by U. S. patent 4,416,421 with powder injection into the throat area for a combustion pressure of 250 psig requires a gas feed pressure of well over 125 psig.
  • the carrier gas pressure required to supply the powder as at 4 can be as low as 50 psig allowing the use of readily available powder feed systems.
  • the powder or rod form solid material is introduced radially to the hot products of combustion rather than axially into the stream, during their radial expansion the ability to concentrate the particles and to prevent them from adhering to the bore of the extended length nozzle is significantly reduced over an arrangement where the solid rod material or particulate material is introduced axially into the stream of gases at its center.
  • FIG. 2 illustrates an internal burner type supersonic flame spray apparatus wherein the same metal or ceramic powder as employed in the Figure 1 embodiment is introduced axially to the extended length nozzle passage or bore 36 of the flame spray apparatus indicated generally at 1'.
  • a main burner body indicated generally at 30 is comprised of an elongated cylindrical portion 30c having integrally formed therewith at one end, an upstream end wall 30a bearing respectively small diameter bores or holes 32, 33 for the supply of oxygen and fuel, respectively, as indicated by arrows 49 and 48.
  • the combustion products exit as a high pressure stream through four longitudinally parallel holes 34 within formed by a cylindrical plug 21 sealably welded, or integrated, to body 30 at the downstream end of the combustion chamber 31.
  • the cylindrical body portion 30c is provided with threads 27 on its outer periphery, at the downstream end thereof.
  • an extended length nozzle indicated generally at 37 is provided with a radially enlarged head 37a, which head is recessed at its outer periphery at 37c so as to fit onto the end of the cylindrical section 30c of body 30.
  • Nozzle 37 comprises an extended length nozzle outlet bore portion or bore 36.
  • a clamping ring 26 which is threaded on its inner periphery as at 28 threads to the body 30 so as to clamp nozzle 37 in position.
  • the longitudinal extent of the recess 37c is such that there is a formed manifold ring volume 42, i. e. an annular space between the head 37a of nozzle 37 and block 21.
  • the block 21 is extended at its downstream end face 21a by a conical projection 43 which is of an axial length so as to project partially within nozzle bore 36.
  • a nozzle throat 35 is thus formed between corner 37d of the extended length nozzle 37 and conical projection 43 at the inlet of the nozzle passage bore 36.
  • annular area at throat 35 may be equal to the area of throat 14 of the embodiment of Figure 1 and functions as the equivalent thereto.
  • Bore 36 may be of the same diameter throughout its length, or alternatively, it may comprise a constant diameter portion as at 36c leading to a diverging section 36d approaching the nozzle outlet 36b. A large expansion of gas flow of the products of combustion takes place within an expanding annular passage 44 from throat 35 to the end of the conical projection 43.
  • a ceramic or metal powder as indicated by arrow 29 is supplied under fairly low pressure carrier gas via powder supply tube 22 which fits to the cylindrical portion 30c of body 30 within a radial hole 23.
  • a radial passage 24 of somewhat smaller diameter extends from bore 23 to the center of plug 21 and a right angle axial bore 25 of relatively small diameter extends therefrom to the end of the conical projection 43 opening to the extended length nozzle bore portion 36c downstream of the expanding annular passage 44 defined by projection 43 and that bore portion 36c. Powder is thus injected into a region where the gas flow velocity is well above Mach 1 and at point of substantially reduced pressure relative to the pressure generated within combustion chamber 31.
  • An advantage of the embodiment of Figure 2 is that the hot gas flow entering the bore 36 from the passage 44 defined by the bore 36 and plug projection 43 envelopes the powder flow symmetrically around a full 360 degrees eliminating areas of recirculation which can carry the powder to the walls of the nozzle passage or bore 36.
  • nozzle passage 36 comprises a constant diameter straight section 36c and an additional diverging expansion passage section 36d, although the complete extended length bore 36 may be of constant, relatively large diameter.
  • the essence of the invention is in its particular applicability to high pressure combustion.
  • the invention is premised on the requirement that an expansion well above critical expansion be provided within the apparatus prior to the introduction of the spray material to the flow. Further, the combustion product gas flow must be in the supersonic range, and the combined hot gases, spray material are then required to be directed through an extended nozzle passage length, throughout which the gas flow velocity remains supersonic.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Combustion & Propulsion (AREA)
  • Nozzles (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
EP84116416A 1984-01-18 1984-12-28 Procédé de pulvérisation à flamme supersonique de grande concentration et appareil à alimentation améliorée Withdrawn EP0163776A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US57177584A 1984-01-18 1984-01-18
US571775 1984-01-18

Publications (2)

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EP0163776A2 true EP0163776A2 (fr) 1985-12-11
EP0163776A3 EP0163776A3 (fr) 1986-12-30

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EP84116416A Withdrawn EP0163776A3 (fr) 1984-01-18 1984-12-28 Procédé de pulvérisation à flamme supersonique de grande concentration et appareil à alimentation améliorée

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EP (1) EP0163776A3 (fr)
JP (1) JPS60169555A (fr)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3620201A1 (de) * 1986-06-16 1987-12-17 Castolin Gmbh Vorrichtung zum thermischen spritzen von auftragsschweisswerkstoffen
US4836447A (en) * 1988-01-15 1989-06-06 Browning James A Duct-stabilized flame-spray method and apparatus
WO1989007016A1 (fr) * 1988-02-01 1989-08-10 Nova-Werke Ag Dispositif pour produire une enveloppe de gaz inerte de protection lors de pulverisation par plasma
FR2630752A1 (fr) * 1988-04-28 1989-11-03 Castolin Sa Procede de pulverisation a la flamme de materiaux en poudre et appareil de pulverisation a la flamme pour la mise en oeuvre de ce procede
EP0361710A1 (fr) * 1988-09-20 1990-04-04 Plasma Technik Ag Dispositif pour la pulvérisation thermique à grande vitesse
US4958767A (en) * 1987-04-29 1990-09-25 Aerospatiale Societe Nationale Industrielle Process and device for injecting a matter in fluid form into a hot gaseous flow and apparatus carrying out this process
EP0412355A1 (fr) * 1989-08-08 1991-02-13 UTP Schweissmaterial GmbH & Co. KG Pistolet-pulvérisateur à flamme de grande vitesse
EP0567569A4 (fr) * 1991-01-16 1994-02-02 James A. Browning
EP0734782A3 (fr) * 1995-03-30 1997-04-23 Draco Ab Procédé et appareil pour l'obtention d'un jet de flamme supersonique à onde de choc stabilisée
CN1045636C (zh) * 1995-07-17 1999-10-13 中南工业大学 喷射沉积设备
DE4429142B4 (de) * 1994-08-17 2004-11-18 Matthäus Götz Düsenspritzkopf zum Hochgeschwindigkeitsflammspritzen so wie Verfahren zur Verarbeitung von Beschichtungspulvern
EP1445343A4 (fr) * 2001-10-15 2004-11-24 Fujimi Inc Procede et systeme de pulverisation thermique

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8992656B2 (en) * 2011-12-21 2015-03-31 Praxair Technology, Inc. Controllable solids injection

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT197162B (de) * 1955-05-02 1958-04-10 Union Carbide Corp Flammspritzverfahren und Vorrichtung zur Durchführung dieses Verfahrens
US2990653A (en) * 1958-04-21 1961-07-04 G H Temant Company Method and apparatus for impacting a stream at high velocity against a surface to be treated
US4121082A (en) * 1977-04-27 1978-10-17 Metco, Inc. Method and apparatus for shielding the effluent from plasma spray gun assemblies
US4256779A (en) * 1978-11-03 1981-03-17 United Technologies Corporation Plasma spray method and apparatus
US4370538A (en) * 1980-05-23 1983-01-25 Browning Engineering Corporation Method and apparatus for ultra high velocity dual stream metal flame spraying
US4416421A (en) * 1980-10-09 1983-11-22 Browning Engineering Corporation Highly concentrated supersonic liquified material flame spray method and apparatus

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3620201A1 (de) * 1986-06-16 1987-12-17 Castolin Gmbh Vorrichtung zum thermischen spritzen von auftragsschweisswerkstoffen
US4958767A (en) * 1987-04-29 1990-09-25 Aerospatiale Societe Nationale Industrielle Process and device for injecting a matter in fluid form into a hot gaseous flow and apparatus carrying out this process
US4836447A (en) * 1988-01-15 1989-06-06 Browning James A Duct-stabilized flame-spray method and apparatus
WO1989007016A1 (fr) * 1988-02-01 1989-08-10 Nova-Werke Ag Dispositif pour produire une enveloppe de gaz inerte de protection lors de pulverisation par plasma
FR2630752A1 (fr) * 1988-04-28 1989-11-03 Castolin Sa Procede de pulverisation a la flamme de materiaux en poudre et appareil de pulverisation a la flamme pour la mise en oeuvre de ce procede
EP0361710A1 (fr) * 1988-09-20 1990-04-04 Plasma Technik Ag Dispositif pour la pulvérisation thermique à grande vitesse
EP0412355A1 (fr) * 1989-08-08 1991-02-13 UTP Schweissmaterial GmbH & Co. KG Pistolet-pulvérisateur à flamme de grande vitesse
EP0567569A4 (fr) * 1991-01-16 1994-02-02 James A. Browning
DE4429142B4 (de) * 1994-08-17 2004-11-18 Matthäus Götz Düsenspritzkopf zum Hochgeschwindigkeitsflammspritzen so wie Verfahren zur Verarbeitung von Beschichtungspulvern
EP0734782A3 (fr) * 1995-03-30 1997-04-23 Draco Ab Procédé et appareil pour l'obtention d'un jet de flamme supersonique à onde de choc stabilisée
CN1045636C (zh) * 1995-07-17 1999-10-13 中南工业大学 喷射沉积设备
EP1445343A4 (fr) * 2001-10-15 2004-11-24 Fujimi Inc Procede et systeme de pulverisation thermique

Also Published As

Publication number Publication date
EP0163776A3 (fr) 1986-12-30
JPS60169555A (ja) 1985-09-03

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