US3797750A - Powder spraying apparatus - Google Patents

Powder spraying apparatus Download PDF

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Publication number
US3797750A
US3797750A US00305140A US3797750DA US3797750A US 3797750 A US3797750 A US 3797750A US 00305140 A US00305140 A US 00305140A US 3797750D A US3797750D A US 3797750DA US 3797750 A US3797750 A US 3797750A
Authority
US
United States
Prior art keywords
conduit
powder
supplementary
pressure
spray gun
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
US00305140A
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English (en)
Inventor
K Herman
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.)
Atlas Copco AB
Original Assignee
Atlas Copco AB
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 Atlas Copco AB filed Critical Atlas Copco AB
Application granted granted Critical
Publication of US3797750A publication Critical patent/US3797750A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24C—ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL
    • B24C7/00—Equipment for feeding abrasive material; Controlling the flowability, constitution, or other physical characteristics of abrasive blasts
    • B24C7/0046—Equipment for feeding abrasive material; Controlling the flowability, constitution, or other physical characteristics of abrasive blasts the abrasive material being fed in a gaseous carrier
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B5/00—Electrostatic spraying apparatus; Spraying apparatus with means for charging the spray electrically; Apparatus for spraying liquids or other fluent materials by other electric means
    • B05B5/025—Discharge apparatus, e.g. electrostatic spray guns
    • B05B5/03—Discharge apparatus, e.g. electrostatic spray guns characterised by the use of gas, e.g. electrostatically assisted pneumatic spraying
    • B05B5/032—Discharge apparatus, e.g. electrostatic spray guns characterised by the use of gas, e.g. electrostatically assisted pneumatic spraying for spraying particulate materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B5/00—Electrostatic spraying apparatus; Spraying apparatus with means for charging the spray electrically; Apparatus for spraying liquids or other fluent materials by other electric means
    • B05B5/16—Arrangements for supplying liquids or other fluent material
    • B05B5/1683—Arrangements for supplying liquids or other fluent material specially adapted for particulate materials
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24C—ABRASIVE OR RELATED BLASTING WITH PARTICULATE MATERIAL
    • B24C5/00—Devices or accessories for generating abrasive blasts
    • B24C5/02—Blast guns, e.g. for generating high velocity abrasive fluid jets for cutting materials
    • B24C5/04—Nozzles therefor

Definitions

  • the present invention relates to a powder spraying apparatus, and more particularly, to a powder spraying apparatus providing improved conveyance of the powder material to the spray gun.
  • a powder spraying apparatus comprises a spray gun, a powder container and a conduit extending from the powder container to the spray gun, which conduit is connected to the spray gun for supplying powder to a spraying material passage therein.
  • the powder container as well as the conduit hitherto normally have been associated with auxiliary means for the transportation of the powder, for example comprising a dispensing gate, a vibratory conveyor and/or an ejector of which at least the ejector has been driven by means ofa gaseous pressure fluid such as compressed air.
  • auxiliary means demand attendance and supervision in order to be operable and often cause operating disturbances because of the tendency of the powder to cake.
  • a powder spraying apparatus includes a spray gun having a spraying material passage therein, a powder supply means and a conduit extending from the powder supply means to the spray gun, the conduit being connected to the spray gun for supplying powder to the spraying material passage therein.
  • the powder supply means in cludes a pressure vessel provided with a powder chamber and a pressure chamber which receives a gaseous pressure fluid. and a wall portion in the pressure vessel between the chambers. The wall portion is permeable to pressure fluid for fluidizing powder in the powder chamber by means of the pressure fluid penetrating through the permeable wall portion.
  • the conduit has a valve associated therewith, and the inlet of the conduit is disposed in the powder chamber for conveying powder fluidized in pressure fluid to the spraying material passage in the spray gun upon actuation of the valve.
  • the conduit includes a main conduit containing a perforated supplementary conduit, the perforated supplementary conduit receiving a gaseous pressure fluid.
  • the pressure fluid penetrates into the main conduit through the perforations in the supplementary conduit to amplify the flowability of the powder when being conveyed in the conduit.
  • the supplementary conduit is preferably a perforated tube or hose loosely inserted into the main conduit which extends over at least a substantial portion of the length of the main conduit.
  • the supplementary conduit may extend over the whole length of the main conduit, and in practice it has been found that'satisfactory results can be achieved even if the supplementary conduit extends only over about 80 per cent of the length of the main conduit.
  • FIG. I shows a powder spraying apparatus according to the invention.
  • FIG. 2 shows partly in section a part of the powder conveying conduit in FIG. 1.
  • the present invention has general application in connection with powder spraying for spreading a spray of powder particles into the surrounding atmosphere through the medium of a spraying device, such as a hand held, fixedly mounted or movably mounted spraying device.
  • a powder spraying apparatus for surface coating purposes in the form of an electrostatic paint spraying plant.
  • the spraying apparatus comprises a spray gun I operating on compressed air and provided with a handle 2 and a gun body 3.
  • a trigger 4 is pivotally journalled on the gun body 3 about an axle 5 and carries an angle member 6.
  • the angle member 6 depresses the spindle of a spring load air valve 7 so that the latter opens.
  • the angle member 6 engages at the other side thereof, via a spring loaded nut sleeve 8, the spindle 9 of a needle valve 10 so as to open the latter.
  • the air valve 7 is supplied with compressed air from a compressed air network 11 via a hose 12 and an adjustable pressure reduction valve 13.
  • compressed air is fed into a distributing chamber 15 and then into the passage 16 which leads to an annular slot 17 in the nozzle 18 of the spray gun 1. From the distributing chamber 15 furthermore runs a passage 20 which leads to side openings 21 in the nozzle 18 for affecting via the side openings 21 the powder spray pattern generated by the spray gun 1.
  • the needle valve 10 closes or opens the outlet of a spraying material passage 22.
  • the needle valve 110 is terminated forwardly by a point 24 and the forward end 23 thereof is metallic or metallized by way of a coating and can be given a high electrostatic tension by an insulated high tension cable 25 which by a pin 26 is in contact with the forward end 23 of needle valve 110.
  • the powder spraying apparatus includes a powder container 29 made as a pressure vessel and provided with a cover 30 which by means of clamps 31 is kept tightly fixed to the powder container 29.
  • a wall 32 traverses the powder container 29 and comprises a wall portion 28 of porous air permeable material, for example a disk of sintered metal.
  • the wall 32 divides the powder spraying container 29 into a powder chamber 33 and a pressure chamber 34.
  • the pressure chamber 34 is supplied with compressed air from the network 11 via an adjustable pressure reduction valve 35 and a conduit 36 which connects to a bottom nipple 37 at the bottom of the powder container 29.
  • a conveying conduit 42 preferably in the shape of a flexible hose which by an open end thereof projects into the powder chamber 33 and at the other end thereof is connected to a nipple 43 which communicates with the spraying material passage 22 in the spray gun I.
  • a supplementary conduit 44 preferably in the shape of a flexible hose of smaller diameter than the conveying conduit 42, passes at one open end 48 thereof through a lead-in sleeve 45, a packing nut 46 and a packing 47 which are affixed to the wall portion 28.
  • the supplementary conduit 44 is slipped and loosely placed into the conveying conduit 42 along substantially the whole or at least the greater part of the length thereof.
  • the end of the supplementary conduit 44 within the conveying conduit 42 is closed by a plug 53 as shown in FIG. 1 near the nipple 43.
  • the supplementary conduit 44 is provided with perforations in the shape of fine bore holes 50, preferably in the order of 1 mm in diameter or smaller.
  • the holes 50 are preferably evenly spaced along the length of the additional conduit 44, for example with a spacing of 30-50 mm.
  • the pressure reduction valves 13 and 35 are adjusted so that a suitable conveying and spray forming pressure isreceived at the air valve 7 in the spray gun 1, and a suitable conveying and fluidizing pressure is created in the chambers 33, 34 of the powder container 29.
  • the high voltage cable 25 of the spray gun I is connected to a conventional electrostatic high voltage generator, not shown.
  • diagrammatically illustrated workpieces 51 are supplied by means of a conveyor 52 to a suitably arranged working place for the gun I.
  • the angle member 6 opens the needle valve 10 and the air valve 7. Because of the resultant pressure drop in the spraying material passage 22, there is pressed, by means of air pressure prevailing in the pressure chamber 34 and the powder chamber 33, powder from the powder chamber 33 into the conveying conduit 42 via the open end of conduit 42 above the wall portion 28. Also, due to the pressure drop. fluidizing air finely distributed by the micropores of the sintered material from the pressure chamber 34 is pressed through the wall portion 28 into the powder mass thereabove so that the powder receives an easily flowable substantially airborne or hovering consistency when it enters into the conduit 42.
  • the powder spraying apparatus according to the present invention is not restricted to the embodiment shown, but has general applicability.
  • the invention is useful for example, for surface coating with or without use of control air out of the openings 17, 21 and with or without electrostatic charging of the powder particles for purposes of decoration or insulation, coating with abrading granules or stone grit, or powdering of diverse objects for medical, zoological or botanical use.
  • a powder spraying apparatus comprising a spray gun having a spraying material passage therein, a powder supply means and a conduit extending from the powder supply means to the spray gun, said conduit being connected to the spray gun for supplying powder to said spraying material passage therein, the improvement wherein:
  • said powder supply means includes: a pressure vessel provided with a powder chamber and a pressure chamber receiving a gaseous pressure fluid; and a wall portion in said pressure vessel between said chambers, said wall portion being permeable to pressure fluid for fluidizing powder in the powder chamber by means of pressure fluid penetrating through said wall portion;
  • a valve is associated with said conduit, and the inlet of said conduit is disposed in the powder chamber for conveying powder fluidized in pressure fluid to said spraying material passage upon actuation of said valve;
  • said conduit includes a main conduit containing a perforated supplementary conduit for a'gaseous pressure fluid, the pressure fluid penetrating into said main conduit from said supplementary conduit through the perforations thereof to thereby amplify the flowability of the powder when being conveyed in the conduit.
  • Apparatus according to claim 1 wherein one end of said supplementary conduit is connected to said pressure chamber in said pressure vessel.
  • a powder spraying apparatus comprising a spray gun having a spraying material passage therein, a powder supply means and a conduit extending from the powder supply means to the spray gun, said conduit being connected to the spray gun for supplying powder to said spraying material passage therein, the improvement wherein:
  • a valve is associated with said conduit; and said powder supply means includes: a pressure vessel provided with a pressure chamber receiving a pressurized gaseous pressure fluid and a powder chamber for maintaining the powder therein under pressure, the inlet of said conduit being disposed in said pressurized powder chamber; and a wall portion in said pressure vessel between said chambers, said wall portion being permeable to pressure fluid for enabling said chambers to be at substantially the same pressure and for fluidizing powder in the powder chamber by means of pressure fluid penetrating through said wall portion upon actuation of said valve, thereby conveying powder fluidized in pressure fluid through said conduit to said spraying material passage upon actuation of said valve.
  • said conduit includes a main conduit containing a perforated supplementary conduit for a gaseous pressure fluid, the pressure fluid penetrating into said main conduit from said supplementary conduit through the perforations thereof to thereby amplify the flowability of the powder when being conveyed in the conduit.
  • Apparatus according to claim 9 wherein one end of said supplementary conduit is connected to said pressure chamber in said pressure vessel.
  • Apparatus according to claim 9 wherein said supplementary conduit extends over at least a substantial portion of the length of said main conduit, said main conduit extending between said pressure vessel and said spray gun.
  • Apparatus according to claim 14 wherein the end of said supplementary conduit remote from said pressure vessel is plugged.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Nozzles (AREA)
  • Electrostatic Spraying Apparatus (AREA)
  • Air Transport Of Granular Materials (AREA)
US00305140A 1971-11-12 1972-11-09 Powder spraying apparatus Expired - Lifetime US3797750A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE7114498A SE387256B (sv) 1971-11-12 1971-11-12 Pulversprutanleggning

Publications (1)

Publication Number Publication Date
US3797750A true US3797750A (en) 1974-03-19

Family

ID=20299204

Family Applications (1)

Application Number Title Priority Date Filing Date
US00305140A Expired - Lifetime US3797750A (en) 1971-11-12 1972-11-09 Powder spraying apparatus

Country Status (7)

Country Link
US (1) US3797750A (enrdf_load_stackoverflow)
BR (1) BR7207913D0 (enrdf_load_stackoverflow)
DE (1) DE2253633B2 (enrdf_load_stackoverflow)
FR (1) FR2155740A5 (enrdf_load_stackoverflow)
GB (1) GB1356525A (enrdf_load_stackoverflow)
SE (1) SE387256B (enrdf_load_stackoverflow)
ZA (1) ZA727866B (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3927833A (en) * 1974-04-29 1975-12-23 Ransburg Corp Apparatus for forming multiple-component composite structures
WO2005043999A1 (en) * 2003-11-10 2005-05-19 Martignani Ing. C. Di Martignani Stefano & C. S.R.L. Crop spraying device
JP2016016459A (ja) * 2014-07-04 2016-02-01 株式会社インベント ブラスト装置
USD1027343S1 (en) * 2023-04-17 2024-05-14 Hefei Yaozhong International Trade Co., Ltd. Powder duster

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2175267B (en) * 1985-05-01 1988-11-16 Kevin Wildon Apparatus for discharging particulate material
SE455574B (sv) * 1985-12-27 1988-07-25 Nordson Icab Ab Anordning vid en med pulverformigt gods fyllbar behallare
GB8616769D0 (en) * 1986-07-09 1986-08-13 Burton J A Cavity wall injecting machine
GB8628930D0 (en) * 1986-12-03 1987-01-07 Mccoll & Co Ltd K G Sand blasting
DE4010914C1 (en) * 1990-04-04 1991-07-11 Wagner International Ag, Altstaetten, Ch Fluidising and convey set=up for electrostatic powder coating appts. - has container pivotable about 180 deg. on frame and with fluidising plate on lid
DE19543960C2 (de) * 1995-11-25 2000-04-06 Driam Metallprodukt Gmbh & Co Sprüharm für eine Beschichtungsvorrichtung
GB2310149A (en) * 1996-02-15 1997-08-20 Nomix Chipman Ltd Spray gun
SE506095C2 (sv) * 1996-12-20 1997-11-10 Ecco Finishing Ab Sprutpistol med vätske och tryckluftsslang

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2934241A (en) * 1956-11-23 1960-04-26 Univ California Compressed air-powered device for fluidizing, metering and distributing dust materials
US3347469A (en) * 1962-01-16 1967-10-17 Patent Holding And Dev Corp Gun for flocking trees
US3367541A (en) * 1966-04-06 1968-02-06 United States Steel Corp Dust distributor

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2934241A (en) * 1956-11-23 1960-04-26 Univ California Compressed air-powered device for fluidizing, metering and distributing dust materials
US3347469A (en) * 1962-01-16 1967-10-17 Patent Holding And Dev Corp Gun for flocking trees
US3367541A (en) * 1966-04-06 1968-02-06 United States Steel Corp Dust distributor

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3927833A (en) * 1974-04-29 1975-12-23 Ransburg Corp Apparatus for forming multiple-component composite structures
WO2005043999A1 (en) * 2003-11-10 2005-05-19 Martignani Ing. C. Di Martignani Stefano & C. S.R.L. Crop spraying device
JP2016016459A (ja) * 2014-07-04 2016-02-01 株式会社インベント ブラスト装置
USD1027343S1 (en) * 2023-04-17 2024-05-14 Hefei Yaozhong International Trade Co., Ltd. Powder duster

Also Published As

Publication number Publication date
ZA727866B (en) 1973-07-25
BR7207913D0 (pt) 1973-09-13
FR2155740A5 (enrdf_load_stackoverflow) 1973-05-18
DE2253633B2 (de) 1977-09-22
GB1356525A (en) 1974-06-12
DE2253633A1 (de) 1973-05-17
SE387256B (sv) 1976-09-06
AU4823172A (en) 1974-05-02
DE2253633C3 (enrdf_load_stackoverflow) 1978-05-24

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