US3801346A - Method for applying particulate coating material to a work piece - Google Patents

Method for applying particulate coating material to a work piece Download PDF

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Publication number
US3801346A
US3801346A US00198806A US3801346DA US3801346A US 3801346 A US3801346 A US 3801346A US 00198806 A US00198806 A US 00198806A US 3801346D A US3801346D A US 3801346DA US 3801346 A US3801346 A US 3801346A
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pressure
chamber
gaseous mixture
mixture
combustion chamber
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US00198806A
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English (en)
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R Melton
W Weatherford
C Wood
J Clark
R Mathis
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ZACHREY H CO
ZACHREY H CO US
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ZACHREY H CO
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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
    • B05B7/0006—Spraying by means of explosions
    • 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
    • C23C4/126—Detonation spraying

Definitions

  • ABSTRACT A system for applying particulate coating material to a work piece, in which the particulate material is directed against the work piece 'in a series of pulses.
  • Each pulse includes an initial step of feeding a charge of combustible gaseous mixture into a combustion chamber provided with an outlet nozzle.
  • the combustible mixture is ignited and the outflow of gaseous mixture through the nozzle is constricted sufficiently to cause a rapid pressure rise during combustion to a peak value, followed by a period of falling pressure during continued outflow of the combusted mixture through the nozzle.
  • a charge of the particulate coating material is injected into the combustion chamber for a brief period which terminates while the pressure in the chamber is at least a substantial proportion of the peak pressure.
  • the outflow of combustion mixture and entrained particulate material is directed through the nozzle at high velocity against the work piece to cause the particulate material to form a coating on the work piece.
  • This invention relates to a method and apparatus for applying particulate coating material to a work piece, and in particular to a system in which the coating material is directed intermittently against the work piece in a heated condition in a high velocity gas stream.
  • coating materials it is advantageous with certain materials in view of their high melting points, non-galvanic properties or for other reasons, to direct the coating material in particulate form against a work piece in a high velocity gas stream at an elevated temperature. If the conditions are carefully chosen, the particles of coating material become flattened and weld to each other and to the work piece to produce a hard, non-porous coating.
  • one prior coating system utilizes a tubular housing fed with continuous streams of acetylene, oxygen and a carrying gas (which may also be oxygen) containing powdered coating material.
  • the gases are ignited continuously within the tubular housing and directed down a water-cooled barrel to impinge upon the work piece in a continuous stream at a velocity of at least 2,000 feet per second.
  • a continuouslyvoperating system subjects the work piece to a large uninterrupted stream of very hot burnt gases which could easily overheat the work piece and subject it to severe thermal erosion or distortion.
  • a combustible gaseous mixture is ignited in a combustion chamber at the upstream end of a gun barrel which is sufficiently long to permit a supersonic detonation wave to be established in and travel down the barrel. Downstream of the combustion chamber particulate coating material is fed into the gun barrel so that the particles are carried down the barrel at high velocity and directed against a suitable work piece.
  • a prior device of this second type may also be unsatisfactory under certain conditions.
  • the need to have a sufficiently long barrel on the device to sus tain a supersonic detonation wave may make the device unnecessarily lengthy for installation at locations where space is at a premium.
  • the opportunity to heat the powder directly in the combustion zone is lost.
  • some of the peak pressure attained in the combustion zone has necessarily already been dissipated.
  • the present invention provides a method and apparatus for applying particulate coating material to a work piece, which is intended to obviate or minimize problems of the type previously described.
  • the method of the present invention directs particulate coating material, e.g., tungsten carbide, against a work piece in a series of pulses.
  • Each pulse includes an initial step of feeding a charge of gaseous combustible mixture into a combustion chamber provided with an outlet nozzle.
  • the combustible mixture is ignited and the outflow of gaseous mixture through the nozzle is constricted sufficiently to cause a rapid pressure rise during combustion of the mixture to a peak value followed by a period of falling pressure during continued outflow of the combusted mixture through the nozzle.
  • a charge of the particulate coating material is injected into the combustion chamber for a period commencing just prior to ignition or altematively, approximately at the time the pressure in the combustion chamber reaches its peak value and terminating while the pressure in the chamber is still a substantial proportion of the peak pressure.
  • the outflow of combusted mixture and entrained particulate material is directed through the nozzle against the work piece at high velocity to cause the particulate material to form a coating on the work piece.
  • Pulse operation also provides more efficient use of fuel as the wastage of combusted gases occurring during a continuous flow against the work piece is avoided.
  • the conditions of pressure and velocity contemplated by the present invention are a peak pressure attained in the chamber of approximately 400 psi and a velocity of outflow of the combusted gases of about 3,000 feet per second with the entrained particulate material traveling at about 1,500
  • FIG. 1 is a side view of an apparatus for applying particulate coating material, constructed in accordance with the preferred embodiment of the invention, showing certain principal elements of the apparatus including a combustion chamber, a fuel inlet unit, and a powder injector,
  • FIG. 2 is a schematic view of a source of combustible gaseous mixture for supplying the apparatus shown in FIG. 1,
  • FIG. 3 is a cross-sectional side view of the combustion chamber shown in FIG. 1,
  • FIG. 4 is a schematic circuit diagram of an ignition circuit for a spark plug connected with the combustion chamber shown in FIG. 1,
  • FIG. 5 is a timing diagram showing the relative periods of operation of various of the principal elements shown in FIG. 1,
  • FIG. 6 is a cross-sectional side view of the fuel inlet unit shown in FIG. 1,
  • FIG. 7 is a cross-sectional top view of the fuel inlet unit shown in FIG. 6 taken along the lines 7-7 therein,
  • FIG. 8 is a cross-sectional side view of the powder injector shown in FIG. 1,
  • FIG. 9A is a schematic electrical circuit diagram showing the electrical connections to an electrical solenoid forming a part of the fuel inlet unit shown in FIG. 6;
  • FIG. 9B is a schematic graph of current and voltage versus time for the electrical circuit shown in FIG. 9A.
  • FIG. 1 of the drawings an apparatus for applying particulate coating material, constructed in accordance with the preferred embodiment of the invention, is there shown.
  • the components of the unit include a combustion chamber 2 shaped generally like an inverted bulb and a downwardly directed nozzle 4 through which particulate coating material entrained in a high velocity gas stream is directed in intermittent pulses at an underlying work piece 6.
  • a fuel inlet unit 8 for periodically feeding a charge of combustible gaseous mixture into the combustion chamber 2
  • a spark plug 10 mounted on the combustion chamber projecting into its interior to ignite the charge of combustible mixture
  • a powder injector unit 12 for feeding in a charge of the particulate material.
  • Many particulate materials may be used including higher melting point coating materials such as tungsten carbide, as well as flaked metal coatings and other coatings. A separate description of these components follows.
  • the combustion chamber 2 which is formed of steel or similar material, is configured generally as an inverted bulb with a flattened, enlarged upper end region of mean diameter D (FIG. 3) tapering down to a reduced neck portion.
  • a block 20 which is threaded to receive the correspondingly threaded upper end of the previously mentioned nozzle 4 which is a short pipe aligned concentrically with the vertical axis of the combustion chamber 2.
  • a horizontal bushing 22 extends through the wall of the combustion chamber 2 into its interior in the upper, enlarged region of the combustion chamber.
  • the bushing 22 is threaded internally and mounts correspondingly threaded portions of the previously mentioned fuel inlet unit 8.
  • the fuel inlet unit 8 injects a charge of combustible gaseous mixture, which in the preferred embodiment is a mixture of propane gas and air, into the interior of the combustion chamber 2.
  • the mixture is then ignited by the previously mentioned spark plug 10 (FIG. 1) which is tapped through the wall of the combustion chamber 2 projecting into its interior.
  • the spark plug is positioned centrally of the enlarged upper portion of the combustion chamber displaced ninety degrees from the inlet unit 8. Other locations may be chosen for the spark plug.
  • the spark ignition plug 10 is a conventional automobile spark plug which, when it is energized, initiates a flame front that extends through the charge of combustible mixture.
  • combustion within the chamber is by deflagration as opposed to detonation, by which it will be understood that the flame front proceeds through the mixture in the combustion chamber at a subsonic velocity, which is about feet per second. In the preferred embodiment it is contemplated that the combustion of the mixture occurs entirely by deflagration.
  • the chamber 2 may be so dimensioned that the pressure rise during deflagration is so rapid that, for a final unbumt portion of the combustible mixture in the chamber, which may be referred to as the end gas, the last part of combustion is by auto-ignition in which spontaneous ignition of the end gas at substantially all the points in it occurs simultaneously.
  • An important characteristic of the chamber in attaining a sufficient pressure rise during combustion to provide a satisfactory coating is the ratio between the diameter of the upper, enlarged portion of the combustion chamber 2 and the diameter of the outlet nozzle 4.
  • the combustible propane air mixture is admitted to the chamber 2 at about psi and it is necessary to achieve a pressure rise to a peak value during combustion of about 400 psi. If the outlet nozzle 4 has too large an internal diameter, too much gaseous mixture may escape through the nozzle before the pressure has built up sufficiently.
  • the ratio of the mean internal diameter D of the combustion chamber of the enlarged upper region to the internal diameter of the nozzle 4 should be at least 5 to l and preferably somewhat greater.
  • the chamber diameter D in its enlarged region is about 2 /2 inches providing a ratio of D/d of 7%.
  • the ratio V/d should exceed about 50 where V is the volume of the chamber in cubic inches and d is the diameter of the opening.
  • the combustion chamber 2 Another important characteristic of the combustion chamber 2 is its overall cubic capacity in relation to the cross-sectional area of the nozzle 4.
  • the cubic capacity of the chamber 2 should be sufficiently large to provide for a period of outflow of gas through the nozzle which lasts sufficiently long to enable the period of injection of the charge of particulate material (which will be described hereinafter) into the combustion chamber to be completed while the pressure in the combustion chamber still remains at a high level.
  • the injection period of the powder can be accomplished in about 5 milli-seconds
  • the period of gas outflow (sometimes called the blow down) during which the gas escapes from the nozzle should be several times longer.
  • a A inch internal diameter nozzle requires a chamber volume of at least eight cubic inches giving a blow down period of about 10 milli-seconds and in practice a chamber capacity of 12-14 cubic inches is provided. With these dimensions, powder can be injected and substantially eliminated from the combustion chamber 2 before the pressure in it has dropped to a value which is too low to project the coating material against the work piece with a sufficient velocity for satisfactory coating.
  • Nozzle length is determined by required powder impact velocity, powder particulate size, and firing pressure, for a given velocity being proportionalto particle size and inversely proportional to firing pressure.
  • the required velocity is that which will hammer particles into a dense, well-bonded coating; too much velocity will break up in-place coating or even remove substrate material while insufficient velocity leaves the coating porous.
  • Temperature plays a subordinate role by softening particles to facilitate impact deformation but temperature is primarily gained from exposure of the powder to hot gas by injecting across the combustion space, with relatively little additional heating occurring in the nozzle.
  • Relatively high firing pressure permits high velocity from a short nozzle; the nozzle could be made much shorter than described here by proportionately increasing firing pressure, or vice-versa, by manipulating powder size and/or fuel-air supply pressure.
  • a coating of tungsten carbide in the 325 mesh 15 micron size range a satisfactory coating was obtained, using a nozzle of 4 inches length, having an amorphous structure with a Knoop hardness of ap- 7 pounds per square inch using standard tests.
  • a soda straw nozzle e.g., one having a length to diameter ratio in excess of 30, has a large amount of wall surface area in relation to its crosssectional area with the result that wall friction appreciably slows down gas flow during passage through the nozzle and there is an additional relatively high, heat loss.
  • the ability to function with a short nozzle facilitates installation of the apparatus in locations where space is at a premium.
  • combustible mixture at psi commences admission to the chamber through the inlet unit 8 (as will be described in more detail hereinafter) for about 8 milliseconds.
  • a charge of the particulate coating material is injected into the chamber and injection of the coating continues until it terminates at about 10 milliseconds.
  • the spark plug 10 ignites the mixture causing a rapid rise in pressure within the combustion chamber to a peak value of about 400 psi attained at about T0 milliseconds after commencement of the cycle.
  • This injection of the powder ceases at approximately the time the pressure in the chamber is at its peak value. At about that time the first particles injected have traveled out of the combustion chamber 2 and through the nozzle 4 to impact the work piece, thus starting a coating period which continues for about 2 milli-seconds.
  • the coating period is shorter than the injection period because the later particles injected catch up with the earlier particles in the nozzle due to the pressure build-up in the chamber.
  • the pressures, times and dimensions described for the preferred embodiment can be selectively varied, if so desired, to facilitate the 'use of larger or smaller coating apparatuses following this invention.
  • the timing of the coating material injection period can be selected to commence after, rather than before ignition, for applications in which it is desirable to introduce the powder into an atmosphere in which all the oxygen has already been combusted, to reduce particle oxidation.
  • the previously mentioned fuel inlet unit 8 (FIGS. 6 and 7) includes a cylindrical inlet housing 30 having a reduced, threaded boss 32 at its forward end which threadedly engages the previously described bushing 22 in the side of the combustion chamber 2. Extending rearwardly into the inlet housing 30 from its forward end is an inlet passage 34 which terminates at about the midpoint of the inlet housing. Extending rearwardly from the inlet passage 34 through the remainder of the inlet housing is a second passage 36, of relatively smaller diameter, which slidably receives a valve stem 38 carrying a valve head 40.
  • valve head 40 which is beveled along its n'm, seats on a correspondingly beveled valve seat 42 on the inlet housing body 30 and closes off fluid communication between the inlet passage 34 and the combustion chamber 2 in a closed position of the valve head.
  • valve stem 38 which projects rearwardly beyond the inlet housing 30, is provided with an undercut, annular groove 42 providing a forwardly facing shoulder 43 which is engaged by a circular collar or spring retainer 44.
  • a circular compression spring 46 spaced concentrically around the valve stem 38 extending between the inlet housing 30 and the collar 44 is just sufficiently strong to hold the valve head 40 closed against the pressure exerted by the incoming supply of combustible gas which is delivered continuously to the interior of the inlet passage 34 through a conduit 48 (FIG. 7).
  • the solenoids 50 are fixedly mounted on the exterior of the inlet housing 30 on opposite sides thereof.
  • the solenoids 50 are of conventional construction, each having an electromagnetic coil 51 (FIG. 9A) with a plunger 52 mounted for axial reciprocation forwardly into the coil when the coil is energized.
  • a transverse yoke 54 Connected to and carried by the plungers 52 is a transverse yoke 54 (FIG. 6) in continuous abutting contact with the free rearward end of the valve stem 38.
  • the biasing spring 46 urges the valve stem 38 to move the yoke 54 rearwardly so that the plungers 52 are in an extended rearward position when the valve head 40 is seated.
  • Energizing the solenoids 50 which causes the plungers 52 to move into the solenoids, carries the yoke 54 forwardly (to the dotted line position shown in FIG. 6) carrying the valve stem 38 forwardly and raising the valve head 40 off its seat.
  • the combustible mixture which is at a pressure of 100 psi in the preferred embodiment, starts to feed into the combustion chamber 2.
  • the solenoids 50 are de-energized at approximately the time the spark plug is fired. The rapid pressure build-up that then occurs in the combustion chamber 2 during charging allows the spring 46 to return the valve head 40 to its seat rapidly closing off the combustion chamber 2 from the inlet passage 34 before the advancing flame front can reach the mixture in the inlet passage.
  • annular recess 56 in the inlet housing 30 surrounds the valve stem at approximately the midpoint of the second passage 36 (FIG. 7 Air is delivered to the passage 56 through a conduit 58, at a higher pressure than the pressure at which the combustible mixture is supplied to the inlet passage 34.
  • Air is delivered to the passage 56 through a conduit 58, at a higher pressure than the pressure at which the combustible mixture is supplied to the inlet passage 34.
  • the flow of gas introduced through the recess 56 is very important for preventing powder from filling the passage around the valve stem and jamming its swift movement between the open and closed positions.
  • the electrical circuit shown in FIG. 9A is employed to energize and de-energize the solenoids 50 for pulsed or cyclical feeding of mixture into the combustion chamber.
  • the preferred rate of operation is at a pulse rate in the region of 5-25 pulses per second although this may be varied.
  • the coil 51 of the solenoid 50 is connected in series with a capacitor 62 which is charged by a high voltage (300 volts) power supply indicated by battery 64 when switch contacts 66a and 66b are closed.
  • switch contacts 66a and 66c are closed the capacitor 62 discharges through the coil 51 of the solenoid moving the associated plunger 52 forwardly.
  • the switch contacts 66a and 66b are remade the capacitor 62 is recharged through coil 66 from power supply 64.
  • a rectifying diode 70 is included in the circuit to the solenoid coil 51 to prevent reverse current flow when the capacitor charge swings in its opposite polarity (FIG. 9B), insuring that the solenoid experiences only a single current pulse. This circuit minimizes the electrical energy drain on the system.
  • a capacitor 70 and a primary coil 72 of a standard ignition transformer, having its secondary coil 73 connected to the spark plug 10, are connected in series with a battery 74.
  • a pair of switch contacts 76 are connected across in parallel with the capacitor 70.
  • the switch contacts 76 are opened and closed by movement of the valve stem 38.
  • the valve stem moves to open the valve head 40 the points 76 close, starting current build-up in the primary coil 72.
  • the points 76 reopen, initiating a voltage change across the coils of the transformer which causes the ignition spark.
  • a supply of combustible mixture is supplied through the conduit 48 to the inlet passage 34 in the inlet unit 8.
  • the supply of combustible mixture is from a source system shown in FIG. 2 which includes a fuel air mixing tank 80 connected to the conduit 48, in which air and propane gas are mixed at a pressure of approximately psi to provide the combustible mixture.
  • a fuel air mixing tank 80 connected to the conduit 48, in which air and propane gas are mixed at a pressure of approximately psi to provide the combustible mixture.
  • Air is supplied to the mixing tank 80 from an air surge tank 82 connected to a high pressure source of air, such as an air line, operating at 100 psi.
  • the air surge tank 82 is connected through an intervening conduit 84 to the mixing tank 80.
  • Propane gas is. supplied to the mixing tank 80 from a bottle 86 containing liquified propane, through connecting conduits 88. Positioned outside the propane bottle 86 are electrical heating lamps 90 which raise the temperature of the liquid propane so that it boils off. The heating of the liquid propane creates a supply of propane gas at about 120 psi and it passes through a variable restrictor 92, interposed in the conduit 88, which controls the supply of propane into the mixing tank 80. Connected in the conduit 88 with a branch connection to the air conduit 84, is a slave regulator 94 which automatically regulates the supply pressure of the propane gas to that of the air pressure.
  • a pressure sensor 98 in fluid communication with the propane gas in the conduit 88 is connected with the electrical supply to the heating lamps 90 for the propane bottle, so that if an excessive pressure rise is detected by the unit 98 it automatically turns off the heating lamps. It is also necessary to turn off the heating lamps 90 when the liquid propane in. the bottle 86- has been exhausted and for this purpose a weight-sensor indicated schematically as 100, is also connected with the propane bottle. The weight-sensor 100 cuts off the electrical supply to the lamps 90 whenever the weight of the bottle 86 and its contents drops below a predetermined level.
  • the mixing tank 80 and the air surge reservoir 82 are of very much larger volumetric capacity than the combustion chamber 2 to minimize variations in supply pressure of the combustible mixture during flow of the gas into the combustion chamber.
  • a source utilizing liquified propane gas has been disclosed, it will be understood that, by appropriate modification, a liquid fuel or mist can be mixed with air and supplied to the combustion chamber to provide the combustion mixture.
  • the previously mentioned powder injector unit 12 includes a vertical, closed hollow cylindrical injector housing 120.
  • the housing 120 has a threaded boss 122 at its lower end which engages a threaded bushing 124 welded to and extending through the wall of the combustion chamber 2 at its upper end.
  • a vertical passage 126 extending through the boss 122, places the interior of the injector housing 120 in fluid communication with the interior of the combustion chamber 2.
  • the passage 126 is normally closed, however, by an injector valve head 128 which seats on an annular neoprene sealing ring 130 mounted in the lower end of the injector housing.
  • the injector valve head 128 may be lifted vertically off its seat 130 by an injector valve stem 132 extending upwardly and outwardly through the upper end of the injector housing 120.
  • the upper end of the injector housing includes a conventional pressure type seal (not shown) permitting verticalsliding motion of the stem 132 without loss of pressure within the housing.
  • a piston 134 Fixedly secured to the stem 132, adjacent the midpoint of the housing, is a piston 134 which divides the interior of the housing into an upper chamber 136 and a lower chamber 138.
  • the piston 134 guides the valve stem for vertical sliding motion to insure that the valve head moves vertically off and onto its seat 130.
  • Particulate material is periodically fed into the lower chamber 138 through a horizontal conduit 140 connected to and extending through the sidewall of the housing 120.
  • a dispenser unit 142 comprising an upper, storage container 144 containing a supply of the coating material and a lower, hopper 146.
  • the storage container 144 is a closed, vertical hollow cylinder having a cone-shaped bottom wall leading into a narrow throat 148.
  • Passing centrally through the storage unit 144 is a vertical shaft 150 having a threaded region 152 at its lower end positioned in the throat 148, spaced from the walls thereof.
  • a valve head 154 is threadedly secured to the bottom of the shaft 152 and has an upwardly directed conical portion which seats on a correspondingly shaped seat at the lower end of the throat 148.
  • valve head 154 Normally, flow through the throat into the underlying hopper 146, which is connected to the storage unit 144 by an intervening neck 160, is prevented by the valve head 154. However, the shaft 150 may be selectively moved downwardly so that particles can pass through the throat 148 into the hopper 146. In addition, the
  • threads 152 at the lower end of the shaft 150 help to I carry particulate material downwardly into the lower hopper. From the hopper 146 the particles pass through the intervening conduit 140 into the lower chamber 138.
  • the quantity of material fed into the powder injector housing 120 on each charge can be controlled. Moreover,
  • a supply of air from a conventional higher pressure source at about 1,000 psi is connected through a supply conduit 162 feeding branch conduits 164, 166 and 168 which are connected to the upper chamber 136, the interior of the storage unit 144, and the interior of the hopper 146, respectively.
  • valve head 128 which gives a particularly rapid and effective valve closing action.
  • the valve stem 132 may be raised and lowered by the use of a solenoid and associated switching circuit, similar to one of the solenoids 50 and associated circuits, previously described in connection with the fuel inlet unit.
  • a solenoid and associated switching circuit similar to one of the solenoids 50 and associated circuits, previously described in connection with the fuel inlet unit.
  • the fuel inlet solenoids, the powder injector solenoid and the spark plug are each energized in response to operation of the switches in their respective associated electrical circuits.
  • the make and break points for the spark plug are mounted on the inlet valve mechanism so that timing of the spark at the desired interval after opening of the inlet valve is achieved automatically.
  • the opening of the powder injector valve in the timed relation previously described is achieved by arranging the switch contacts to the powder injector solenoid to close approximately 3 milliseconds after the fuel inlet valve head 40 commences to open. This can be achieved by mounting cams on a common rotating shaft controlling the operation of the switches controlling the inlet valve and the powder injector plunger in
  • the coating material instead of being introduced into the chamber separately from the combustible mixture, may be introduced into the chamber already mixed with the combustible mixture. This may advantageously be done by introducing the coating material into the line 48 between the fuel/air source and the fuel inlet valve or, alternatively, by introducing the coating material into the chamber 34 within the fuel inlet valve 8 via a suitable conduit. In either event the coating material enters the combustion chamber with the combustible mixture.
  • the method of claim 1 wherein the particulate material is introduced to the gaseous mixture before a major portion of the gaseous mixture has been directed through the nozzle. 5. The method of claim 1 wherein a portion of the gaseous mixture is combusted by auto ignition after the pressure of the gaseous mix- 5 ture has been increased by deflagration ti. The method of claim 1 wherein the particulate his injecting particulate coating material into the combustion chamber so that the particulate material will be preheated before leaving the combustion chamber, and

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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)
  • Nozzles (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Coating By Spraying Or Casting (AREA)
US00198806A 1971-11-15 1971-11-15 Method for applying particulate coating material to a work piece Expired - Lifetime US3801346A (en)

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US4004735A (en) * 1974-06-12 1977-12-25 Zverev Anatoly Apparatus for detonating application of coatings
US4067291A (en) * 1974-04-08 1978-01-10 H. B. Zachry Company Coating system using tape encapsulated particulate coating material
US4243699A (en) * 1977-12-20 1981-01-06 Gibson Jack Edward Method of powder coating the inside of pipes with a continuous film of plastic material
WO1984001115A1 (en) * 1982-09-23 1984-03-29 Zachry Co H B Repetitive combustion coating apparatus
US4826734A (en) * 1988-03-03 1989-05-02 Union Carbide Corporation Tungsten carbide-cobalt coatings for various articles
USRE32921E (en) * 1976-07-13 1989-05-09 GCB, Inc. Method of powder coating the inside of pipes with a continuous film of plastic material
US4902539A (en) * 1987-10-21 1990-02-20 Union Carbide Corporation Fuel-oxidant mixture for detonation gun flame-plating
US4909914A (en) * 1985-05-11 1990-03-20 Canon Kabushiki Kaisha Reaction apparatus which introduces one reacting substance within a convergent-divergent nozzle
US4911805A (en) * 1985-03-26 1990-03-27 Canon Kabushiki Kaisha Apparatus and process for producing a stable beam of fine particles
US5223332A (en) * 1990-05-31 1993-06-29 Praxair S.T. Technology, Inc. Duplex coatings for various substrates
US5405085A (en) * 1993-01-21 1995-04-11 White; Randall R. Tuneable high velocity thermal spray gun
US5445325A (en) * 1993-01-21 1995-08-29 White; Randall R. Tuneable high velocity thermal spray gun
US5520334A (en) * 1993-01-21 1996-05-28 White; Randall R. Air and fuel mixing chamber for a tuneable high velocity thermal spray gun
US6146693A (en) * 1995-12-26 2000-11-14 Aerostar Coatings, S.L. Energy bleed apparatus and method for a detonation gun
US20160138150A1 (en) * 2012-04-24 2016-05-19 Aereus Technologies Inc. Coatings, coated surfaces, and methods for production thereof

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US4288306A (en) * 1978-07-08 1981-09-08 Wolfgang Kieferle Process for forming a metal or alloy layer and device for executing same
DE3105323A1 (de) * 1981-02-13 1982-09-02 Vorošilovgradskij mašinostroitel'nyj institut SSSR, Vorošilovgrad Schaft einer einrichtung zum detonationsgasaufstaeuben von ueberzuegen
CH674951A5 (ja) * 1988-02-26 1990-08-15 Castolin Sa
GB2276886B (en) * 1993-03-19 1997-04-23 Smith International Rock bits with hard facing
AU1424897A (en) * 1995-12-26 1997-07-17 Aerostar Coatings, S.L. Pulsed powder feeder apparatus and method for a detonation gun
TWI551727B (zh) * 2015-03-20 2016-10-01 漢翔航空工業股份有限公司 以丙烷當燃氣用於超合金表面噴塗抗磨塗層之方法
RU2755783C1 (ru) * 2020-11-23 2021-09-21 Иван Андреевич Безбородов Способ напыления покрытий с помощью оружейного пороха и установка для его реализации

Cited By (17)

* Cited by examiner, † Cited by third party
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US3910494A (en) * 1974-02-21 1975-10-07 Southwest Res Inst Valveless combustion apparatus
US4067291A (en) * 1974-04-08 1978-01-10 H. B. Zachry Company Coating system using tape encapsulated particulate coating material
US4004735A (en) * 1974-06-12 1977-12-25 Zverev Anatoly Apparatus for detonating application of coatings
USRE32921E (en) * 1976-07-13 1989-05-09 GCB, Inc. Method of powder coating the inside of pipes with a continuous film of plastic material
US4243699A (en) * 1977-12-20 1981-01-06 Gibson Jack Edward Method of powder coating the inside of pipes with a continuous film of plastic material
WO1984001115A1 (en) * 1982-09-23 1984-03-29 Zachry Co H B Repetitive combustion coating apparatus
US4469722A (en) * 1982-09-23 1984-09-04 H. B. Zachry Company Repetitive combustion coating apparatus
US4911805A (en) * 1985-03-26 1990-03-27 Canon Kabushiki Kaisha Apparatus and process for producing a stable beam of fine particles
US4909914A (en) * 1985-05-11 1990-03-20 Canon Kabushiki Kaisha Reaction apparatus which introduces one reacting substance within a convergent-divergent nozzle
US4902539A (en) * 1987-10-21 1990-02-20 Union Carbide Corporation Fuel-oxidant mixture for detonation gun flame-plating
US4826734A (en) * 1988-03-03 1989-05-02 Union Carbide Corporation Tungsten carbide-cobalt coatings for various articles
US5223332A (en) * 1990-05-31 1993-06-29 Praxair S.T. Technology, Inc. Duplex coatings for various substrates
US5405085A (en) * 1993-01-21 1995-04-11 White; Randall R. Tuneable high velocity thermal spray gun
US5445325A (en) * 1993-01-21 1995-08-29 White; Randall R. Tuneable high velocity thermal spray gun
US5520334A (en) * 1993-01-21 1996-05-28 White; Randall R. Air and fuel mixing chamber for a tuneable high velocity thermal spray gun
US6146693A (en) * 1995-12-26 2000-11-14 Aerostar Coatings, S.L. Energy bleed apparatus and method for a detonation gun
US20160138150A1 (en) * 2012-04-24 2016-05-19 Aereus Technologies Inc. Coatings, coated surfaces, and methods for production thereof

Also Published As

Publication number Publication date
FR2160390A1 (ja) 1973-06-29
DE2250750A1 (de) 1973-05-24
HU174657B (hu) 1980-02-28
CA984233A (en) 1976-02-24
IT980990B (it) 1974-10-10
NL7215183A (ja) 1973-05-17
NO139912C (no) 1979-06-06
PL79703B1 (ja) 1975-06-30
JPS4859138A (ja) 1973-08-18
SE398979B (sv) 1978-01-30
GB1415345A (en) 1975-11-26
AU4853072A (en) 1974-05-09
NO773683L (no) 1973-05-16
DD101705A5 (ja) 1973-11-12
AU467770B2 (en) 1975-12-11
IL40695A0 (en) 1972-12-29
FR2160390B1 (ja) 1979-01-12
AR195981A1 (es) 1973-11-23
IL40695A (en) 1974-09-10
BR7207932D0 (pt) 1974-12-31
ZA727456B (en) 1974-05-29
DE2250750C2 (de) 1982-09-02
CS170455B2 (ja) 1976-08-27
BE790902A (fr) 1973-05-03
NO139912B (no) 1979-02-26
JPS5547944B2 (ja) 1980-12-03

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