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
  • B05B7/144—Arrangements for supplying particulate material the means for supplying particulate material comprising moving mechanical means

Definitions

• the present invention relates to a pump for powdery products, in particular for powders used in painting.
• powder to be applied to an object to be painted is more and more common, in particular for important metallic parts, like frames of machines or car bodies.
• paint in powder form is introduced into a jet of pressurized air and is sprayed onto the part to be painted, against which it adheres by electrostatic effect.
• the powder layer is then polymerized, by heating or any other suitable means, so as to permanently adhere the powder against the part.
• the present invention relates to a pump making it possible to withdraw the powder from a stock of powder and to introduce it into a flow of air under pressure, in order to project it against the part to be painted.
• a first object of the invention is therefore to propose a pump for powdered products which is improved compared to known pumps and devices, that is to say which does not have their drawbacks.
• Another object of the invention is to provide a pump for pulverulent products which is of simple and compact, light design and construction, which can be placed in the immediate vicinity of the projection device.
• Another object of the invention is to provide a pump for powdery products capable of spraying a powdery product in a regular, continuous and exactly dosed manner.
• Yet another object of the invention is to provide a pump for pulverulent products capable of thinning the powder before it is introduced into the flow of transport air.
• FIG. 1 is a schematic representation of a powder painting installation showing the integration of a pump according to the invention in said installation
• FIG. 2 is a schematic longitudinal section of a body of a pump according to the invention
• FIG. 3 is a cross section along the line III-III of the preceding figure
• FIG. 4 is a cross section along the line IV-IV of FIG. 2,
• FIG. 4a is a partial enlarged view of FIG. 4,
• FIG. 5 is a cross section along the line V-V of FIG. 2.
• the powder paint installation 1 shown diagrammatically in FIG. 1 comprises a device 2 making it possible to project a jet of powder paint via a pipe 3 and a projection device 30, like a spray gun, against an object to be painted 4.
• the device 2 is supplied with powder 5 either by gravity from a hopper 50 or, as shown in broken lines, by suction from a tank 51.
• the device 2, capable of fulfilling the functions described above, represents the pump for powdery products according to the invention.
• FIG. 2 shows a view in longitudinal section of a pump for powdery products 2 according to an embodiment of the invention.
• the pump 2 as shown here consists of a pump body 20, a hopper support part 21, and a collecting part 22, these three elements being fixed together by known means, shown diagrammatically at 23.
• the pump body 20 comprises a first cylindrical hollow housing 200, intended to receive, in the embodiment shown, a pumping part 24, here a gear wheel, which gear is driven in rotation by a shaft 240 extending into a second hollow housing 201, coaxial with the first hollow housing 200 and comprising the means for rotating the shaft 240, for example one or more bearings 241.
• the shaft 240 is connected to the means for supplying mechanical energy 62 supplied and regulated by the control unit 6 seen above.
• the bottom face 202 of the first hollow housing 200 comprises a plurality of injection nozzles 203 arranged side by side on a portion of an interior perimeter of said housing. These injection nozzles 203 communicate with an injection chamber 204 arranged in the pump body 20, itself connected by a pipe to a pressurized gas inlet 631, as seen in FIG. 2.
• the body 20 also comprises a powder supply conduit 205, connected to a corresponding conduit of the hopper support part 21 and opening into the bottom opening of the hopper 50.
• the other end of the powder supply conduit 205 opens into the upper part of the first hollow housing 200.
• the conduit 205 therefore puts the first hollow housing 200 into communication with the powder supply hopper 50.
• the body 20 is still traversed by a pipe 206 connected on the one hand to a second inlet for pressurized gas 632 and opening on the other hand into a collecting chamber 220, arranged in the collecting piece 22.
• This collecting chamber 220 is connected by a pipe 221 to the pipe 3 for spraying powder paint.
• FIG. 4 shows the gear 24 in its housing 200. It can be seen in FIG. 4a that, in the embodiment shown, the angular distance separating each nozzle 203 corresponds to a toothing pitch of the gear 24.
• FIG. 5 shows the face of the collecting piece 22 applied against the pump body 20.
• the shape of the collecting chamber 220 is determined so as to be able to collect with maximum efficiency the powder blown by the injection nozzles 203 and to mix it intimately with the flow of transport air from line 206.
• the shape shown here is one of several possible shapes.
• the hopper 50 is first of all filled with powder, the latter first flowing by gravity through the line 205 to fill the spaces between the teeth of the gear 24 arranged opposite the outlet of the line 205 in the first accommodation 200.
• the motorized means 60 for example an electric motor, are put into action to drive the gear 24 in clockwise rotation in FIG. 4, via the means of transmission of the mechanical energy 62 and of the shaft 240.
• the speed of rotation of the gear 24 is relatively low, so that the interdental spaces of the gear 24 are correctly filled with powder when they pass in front of the outlet of the pipe 205.
• the control unit 6 supplies the injection chamber 204 via a first pipe 631, with a gas, preferably air, with a first flow rate and under a first pressure. This gas then passes through the injection nozzles 203 to expel the powder contained between the teeth of the gear 24. For a determined interdental space, which is filled with powder during its passage opposite the outlet of the pipe 205 , and which arrives in front of the first nozzle
• control unit 6 supplies the line 206, via a second line 632, with a gas, preferably air, with a second flow rate and under a second pressure.
• a gas preferably air
• This gas flow is introduced into the collecting chamber 220, in order to mix intimately with the powder which has been simultaneously introduced therein, as described above, then transport it, via pipes 221 and 3 to the projection device 30.
• the pulsation effect can be eliminated by providing a series of nozzles 203, of gas passage cross section under equal or increasing pressure, but arranged so that they are never simultaneously uncovered by a gear tooth identically; for example for a determined angular position of the gear, there would be the first nozzle completely uncovered, the last nozzle completely covered, the intermediate nozzles being partially and progressively covered.
• This constructive arrangement can be combined with a straight or helical shape of the teeth of the gear 24.
• the elimination of the pulsating effect can be obtained by a combination of the various means. described above, number, spacing and section of the nozzles, shape of the gear and shape of the collecting chamber.
• Pump 2 has been described and shown as being supplied from above, by gravity from a hopper. It would also be possible to turn the pump over and feed it from below, by suction from a tank, as shown in broken lines in FIG. 1. In this case, an auxiliary pumping means, not shown in the figure can be used to supply the pump 2 with powdery product.
• the pump 2 comprises means, taking a portion of the pressurized gas introduced into the first housing 200 and sending it towards the hopper, via the line 205. There is thus a slight flow of gas, preferably air, brewing the powder contained in the hopper in order to fluidize it and prevent the formation of a blocking vault.
• These means may consist, for example, of grooves 25 arranged radially on one or both lateral faces of the gear 24, as seen in FIG.
• this pump has been described using a gear as a pumping means; in fact the pumping part 24 can consist of any member of revolution comprising a plurality of chambers, regularly distributed over its outer periphery, each of the chambers being able to be individually filled with powder in a radial direction and emptied of its powder in an axial direction or slightly inclined relative to this axial direction, as in the case of the helical toothing of the gear.
• the gear shown in the figures is therefore only one possible embodiment of this pumping part.
• the granulometry of the powder as well as the desired powder flow rate on the object to be painted are the main parameters enabling the gas pressures, preferably compressed air, introduced by the lines 631 and 632 to be adjusted, as well as the speed of rotation of the pumping part, these quantities being regulated by the control unit 6.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Nozzles (AREA)
• Cyclones (AREA)
• Air Transport Of Granular Materials (AREA)
• Formation And Processing Of Food Products (AREA)
• Manufacturing Of Micro-Capsules (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=29410161

Family Applications (1)

Country Status (5)

Cited By (1)

Family Cites Families (4)

• 2003
  • 2003-04-14 AT AT03709551T patent/ATE330708T1/de not_active IP Right Cessation
  • 2003-04-14 WO PCT/CH2003/000248 patent/WO2003095099A1/fr not_active Application Discontinuation
  • 2003-04-14 DE DE60306366T patent/DE60306366T2/de not_active Expired - Fee Related
  • 2003-04-14 AU AU2003213976A patent/AU2003213976A1/en not_active Abandoned
  • 2003-04-14 EP EP03709551A patent/EP1503862B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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