EP1952892B1 - Powder spray coating facility and powder spray coating method - Google Patents

Powder spray coating facility and powder spray coating method Download PDF

Info

Publication number
EP1952892B1
EP1952892B1 EP07120752.6A EP07120752A EP1952892B1 EP 1952892 B1 EP1952892 B1 EP 1952892B1 EP 07120752 A EP07120752 A EP 07120752A EP 1952892 B1 EP1952892 B1 EP 1952892B1
Authority
EP
European Patent Office
Prior art keywords
powder
recovered
fresh
reservoir
spray coating
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.)
Active
Application number
EP07120752.6A
Other languages
German (de)
French (fr)
Other versions
EP1952892A1 (en
Inventor
Felix Mauchle
Mark Steinemann
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.)
Gema Switzerland GmbH
Original Assignee
Gema Switzerland GmbH
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 Gema Switzerland GmbH filed Critical Gema Switzerland GmbH
Publication of EP1952892A1 publication Critical patent/EP1952892A1/en
Application granted granted Critical
Publication of EP1952892B1 publication Critical patent/EP1952892B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
    • B05B7/14—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas designed for spraying particulate materials
    • B05B7/1404—Arrangements for supplying particulate material
    • B05B7/1454—Arrangements for supplying particulate material comprising means for supplying collected oversprayed particulate material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B12/00—Arrangements for controlling delivery; Arrangements for controlling the spray area
    • B05B12/08—Arrangements for controlling delivery; Arrangements for controlling the spray area responsive to condition of liquid or other fluent material to be discharged, of ambient medium or of target ; responsive to condition of spray devices or of supply means, e.g. pipes, pumps or their drive means
    • B05B12/081—Arrangements for controlling delivery; Arrangements for controlling the spray area responsive to condition of liquid or other fluent material to be discharged, of ambient medium or of target ; responsive to condition of spray devices or of supply means, e.g. pipes, pumps or their drive means responsive to the weight of a reservoir or container for liquid or other fluent material; responsive to level or volume of liquid or other fluent material in a reservoir or container
    • 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
    • B05B7/1472—Powder extracted from a powder container in a direction substantially opposite to gravity by a suction device dipped into the powder
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B12/00—Arrangements for controlling delivery; Arrangements for controlling the spray area
    • B05B12/14—Arrangements for controlling delivery; Arrangements for controlling the spray area for supplying a selected one of a plurality of liquids or other fluent materials or several in selected proportions to a spray apparatus, e.g. to a single spray outlet
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
    • B05B14/00—Arrangements for collecting, re-using or eliminating excess spraying material
    • B05B14/40—Arrangements for collecting, re-using or eliminating excess spraying material for use in spray booths
    • B05B14/48—Arrangements for collecting, re-using or eliminating excess spraying material for use in spray booths specially adapted for particulate material

Definitions

  • the invention relates to a powder spray coating system according to the preamble of the independent claims.
  • a plant is from the CH 529 590 A known.
  • Pulversprühbe Anlagensanlagen are for example from the US Pat. No. 3,960,323 . US 3,918,641 . EP 0 412 289 B2 . DE 42 39 496 A1 and DE 103 53 968 A1 known.
  • the object of the invention is to achieve a more efficient powder spray coating and powder spray coating process.
  • Fig. 1 schematically shows a preferred embodiment of a powder spray coating system according to the invention for spray coating of objects 2 with coating powder, which is then melted in a furnace, not shown, on the object.
  • One or more electronic control units 3 are provided for controlling the functions of the powder spray coating system.
  • For pneumatic conveying of the coating powder powder pumps 4 are provided. These can be injectors, in which coating powder is sucked by means of compressed air serving as compressed air from a powder container, after which then the mixture of conveying air and coating powder flows together into a container or to a spraying device.
  • Injectors are z. B. from the EP 0 412 289 B1 known.
  • a powder pump and those types of pumps can be used which convey small portions of powder by means of compressed air in succession, each one small powder portion (powder) stored in a powder chamber and then pushed out of the powder chamber by means of compressed air. The compressed air remains behind the powder portion and pushes the powder portion in front of him.
  • These types of pumps are sometimes referred to as pneumatic push pumps or plug-lift pumps because the compressed air pushes the stored powder portion through a pump outlet line like a plug.
  • Various types of such powder pumps for conveying dense coating powder are known, for example, from the following documents: DE 103 53 968 A1 . US 6,508,610 B2 . US 2006/0193704 A1 . DE 101 45 448 A1 . WO 2005/051549 A1 ,
  • the invention is not limited to any of the mentioned types of powder pumps.
  • a compressed air source 6 is provided, which via corresponding Druckeinstellelemente 8, z. B. pressure regulator and / or valves, is connected to the various devices.
  • Fresh powder from a powder supplier is from a supplier container, which, for example, a small container 12 z. B. in the form of a dimensionally stable container or a bag with a powder amount of, for example, between 10 to 50 kg, z. B. 25 kg, or z. B. a large container 14, for example, also a dimensionally stable container or bag, with a powder amount between, for example, 100 kg and 1000 kg may be supplied by means of a powder pump 4 in a fresh powder line 16 or 18 of a screening device 10.
  • the screening device 10 may be provided with a vibrator 11.
  • the terms "small container” and “large container” respectively mean both "dimensionally stable container” and “non-dimensionally stable, flexible bag", except where expressly referred to one or the other Be Strukturnisart.
  • the coating powder sieved by the sieve device 10 is conveyed by gravity or preferably in each case by a powder pump 4 via one or more powder feed lines 20 through powder inlet openings 26 into an intermediate container chamber 22 of a dimensionally stable intermediate container 24.
  • the volume of the intermediate container chamber 22 is preferably substantially smaller than the volume of the fresh powder small container 12.
  • the powder pump 4 of the at least one powder supply line 20 to the intermediate container 24 is a compressed air push pump.
  • the initial portion of the powder supply line 20 may serve as a pump chamber, in which sieved by the sieve 10 powder through a valve, for. B. a pinch valve falls. After this pump chamber contains a certain powder portion, the powder supply line 20 is fluidly separated by closing the valve of the sieve device 10. After that, the Powder portion pushed by compressed air through the powder supply line 20 into the intermediate container chamber 20.
  • the powder inlet openings 26 are preferably arranged in a side wall of the intermediate container 24, preferably near the bottom of the intermediate container chamber 22, so that when flushing the intermediate container chamber 22 by means of compressed air also on the ground located powder residues can be driven out through the powder inlet openings 26, for which purpose the powder supply lines 20 preferably from the screening device 10 are separated and directed into a waste container, as in Fig. 1 is indicated schematically by a dashed arrow 28.
  • a plunger 30 provided with compressed-air nozzles can be moved through the intermediate container chamber 22.
  • Pulverauslassö réelleen 36 are powder pumps 4, z. B. injectors, connected to spray devices 40 for conveying coating powder through powder lines 38.
  • the spray devices 40 may include spray nozzles or rotary atomizers for spraying the coating powder 42 onto the object 2 to be coated, which is preferably located in a coating booth 43.
  • the powder outlet openings 36 are preferably located in a wall opposite the wall in which the powder inlet openings 26 are located.
  • the powder outlet openings 36 are preferably also located near the bottom of the intermediate container chamber 22.
  • the tundish chamber 22 preferably has a size which is within the range of a capacity of coating powder between 1.0 kg and 12 kg, preferably between 2.0 kg and 8.0 kg.
  • the size of the intermediate reservoir chamber 22 is preferably between 500 cm 3 and 30 000 cm 3 , preferably between 2000 cm 3 and 20 000 cm 3 .
  • the size of the intermediate container chamber 22 is selected in dependence on the number of powder outlet openings 36 and the powder lines 38 connected thereto in such a way that a continuous spray coating operation is possible, However, the intermediate container chamber 22 can be cleaned quickly in coating pauses for a powder change, preferably automatically.
  • the intermediate container chamber 22 may be provided with a fluidizing device for fluidizing the coating powder.
  • Coating powder 42 which does not adhere to the object 2, is sucked as excess powder via a surplus powder line 44 into a cyclone separator 48 by means of a suction air flow of a blower 46.
  • the excess powder is separated in Zyklonabscheider 48 as far as possible from the suction air stream.
  • the separated powder portion is then passed as a recovery powder from the cyclone 48 via a powder recovery line 50 to the sifter 10, where it passes through the sifter 10, either alone or mixed with fresh powder via the powder supply lines 20 back into the intermediate container chamber 22.
  • FIG Fig. 1 is shown schematically by a dashed line 51.
  • the powder recovery line 50 in order not to be separated from the screening device 10, may be provided with a switch 52, to which it is alternatively connectable to the screening device 10 or to a waste container.
  • the intermediate container 24 may have one or more, for example two sensors S1 and / or S2, in order to control the supply of coating powder into the intermediate container chamber 22 by means of the control unit 3 and the powder pumps 4 in the powder feed lines 20.
  • the lower sensor S1 detects a lower powder level limit
  • the upper S2 sensor detects an upper powder level limit.
  • the lower end portion 48-2 of the cyclone 48 may be formed and used as a reservoir for recovery powder and provided with one or more, for example, two sensors S3 and / or S4, which are functionally connected to the control unit 3.
  • the fresh powder feed through the fresh powder feed lines 16 and 18 are automatically stopped as long as there is sufficient recovery powder in the cyclone separator 48 to supply the intermediate tank chamber 22 through the sieve apparatus 10 with recovery powder in a sufficient amount required for the spray coating operation by means of the spray devices 40. If there is no longer sufficient recovery powder in the cyclone separator 48, then the supply of fresh powder through the fresh powder supply lines 16 or 18 can be switched over automatically. Furthermore, it is also possible to feed fresh powder and recovery powder simultaneously to the sieve device 10 so that they are mixed together.
  • the exhaust air of the cyclone 48 passes through an exhaust duct 54 in a Nachfiltervorraum 56 and therein by one or more filter elements 58 to the fan 46 and after this in the outside atmosphere.
  • the filter elements 58 may be filter bags or filter cartridges or filter plates or similar filter elements.
  • the separated by the filter elements 58 from the air flow powder is usually waste powder and falls by gravity into a waste container or can, such as Fig. 1 shows, via one or more waste lines 60, each containing a powder pump 4, are conveyed into a waste container 62 at a waste station 63.
  • the waste powder may also be recovered to the screening device 10 to re-enter the coating circuit.
  • Fig. 1 represented by switches 59 and branch lines 61 of the waste lines 60 schematically.
  • cyclone separator 48 is usually used in combination with post-filter device 56 only if it is a problematic coating powder.
  • recovery powder of the cyclone 48 is supplied via the powder recovery line 50 of the sieve 10, while the waste powder of the Nachfiltervoriques 56 as waste in the waste container 62 or in another waste container, the latter without waste lines 60 directly below an outlet opening of the Nachfiltervortechnisch 56th can be made.
  • the lower end of the cyclone device 48 may include an outlet valve 64, such as a pinch valve. Furthermore, a fluidizing device 66 for fluidizing the coating powder may be provided above this outlet valve 64, in or at the lower end of the, designed as a reservoir, lower end portion 48-2 of the cyclone 48.
  • the fluidizing device 66 includes at least one fluidising wall 80 of an open-pore or narrow-bore material which is pervious to compressed air but not to coating powder.
  • the fluidizing wall 80 is disposed between the powder path and a fluidizing compressed air chamber 81.
  • the fluidizing compressed-air chamber 81 can be connected to the compressed-air source 6 via a pressure-adjusting element 8.
  • the fresh powder line 16 and / or 18 may be fluidly connected at its upstream end, either directly or through the powder pump 4, to a powder delivery tube 70 which is submerged in the supplier vessel 12 or 14 for aspiration of fresh coating powder.
  • the powder pump 4 may be disposed at the beginning, at the end or in between in the fresh powder line 16 or 18 or at the upper or lower end of the powder conveying tube 70.
  • Fig. 1 shows as fresh powder small container a fresh powder powder bag 12 in a bag receiving hopper 74.
  • the powder bag 12 is held by the bag receiving hopper 74 in a defined shape, the bag opening is located at the upper bag end.
  • the bag receiving hopper 74 may be disposed on a scale or weighing sensors 76. Depending on the type, this balance or the weighing sensors can generate an optical display and / or an electrical signal which, after subtracting the weight of the bag receiving hopper 74, corresponds to the weight and thus also the amount of the coating powder in the small container 12.
  • At the bag receiving hopper 74 at least one vibrator 78 vibrating it is preferably arranged.
  • Two or more small containers 12 can each be provided in a bag receiving hopper 74 and / or two or more large containers 14, which can be used alternatively. As a result, a quick change from one to another small container 12 or large container 14 is possible.
  • the screening device 10 can be integrated into the intermediate container 24. Furthermore, the screening device 10 can be omitted if the fresh powder has a sufficiently good quality. In this case, it is also possible to use for sieving the recovery powder of the lines 44 and 50, a separate sieve, z. Upstream or downstream of the cyclone shut-off 48 or in the cyclone shut-off 48. Also, the recovery powder will not require a sieve if its powder grade is sufficiently good for reuse.
  • Fig. 2 shows, opposite Fig. 1 It contains the pressurized air permeable but coating powder impermeable fluidizing wall 80 between the powder path at the lower end of the reservoir 48-2 and the fluidizing pressurized air chamber 81 extending above the fluidizing wall 80.
  • Compressed air of the compressed air source 6 passes through a control 8, z.
  • Die Fluidisierwand 80 can the lower end of the Form end portion 48-2 over a powder outlet 204 of the end portion 48-2 completely or partially.
  • Two or more fluidizing walls 80 and fluidizing compressed air chambers 81 can be distributed over the circumference of the end portion 48-2 formed as a reservoir.
  • the exhaust valve 64 has a vertical distance 202 from the measurement level of the upper sensor S3 and a vertical distance 206 from the measurement level of the lower sensor S4 of the end portion 48-2.
  • the volume of the reservoir-serving end portion 48-2 between the two sensors S3 and S4 defines a predetermined reserve volume for recovery powder.
  • Powder spray coating system comprising an intermediate container (24), from which coating powder is pneumatically conveyable to at least one spray device (40); at least one sensor (S1) on the intermediate container (24) for generating a powder requirement signal when the powder level in the intermediate container (24) has fallen below a predetermined minimum powder level; a cyclone separator (48) for separating recovery powder from a stream of air containing sprayed excess powder which missed an object to be coated; in which, a recovery powder reservoir (48-2) is disposed on the way of the recovery powder from the cyclone separator (48) to the intermediate container (24) for temporarily storing the recovery powder in the recovery powder storage container (48-2) before being supplied to the intermediate container (24) ; in that the recovery powder storage container (48-2) is provided with at least one storage tank sensor (S3) for generating a recovery powder information signal in dependence on whether the powder level is below a minimum level or at least at the minimum level is; in that a fresh powder supply device (70, 74) is provided for supplying fresh powder powder from a
  • the at least one control unit (3) for automatic switching of the powder spray coating plant from the second operating phase to a reserve operating phase is formed, in which only recovery powder from the powder reserve section (202) of the recovery powder storage tank (48-2) is fed to the intermediate tank (24), However, no fresh powder from the fresh powder supply device (70, 74), if after a predetermined delay time after switching from the first phase of operation to the second phase of operation further from the tundish sensor (S1) a powder demand signal is present, said at least one control unit (3) contains a delay circuit which defines the delay time or at which the delay time is variably adjustable.
  • the recovery powder reservoir (48-2) is provided with a second reservoir sensor (S4) for generating a distress signal each time the recovery powder level in the recovery powder reservoir (48-2) has dropped to a predetermined lower limit level a predetermined distance below the predetermined recovery powder minimum level of the first reservoir sensor (S3).
  • Powder spray coating system according to one of the preceding embodiments, characterized, that the recovery powder storage container (48-2) is disposed below the cyclone separator (48) and between which a vertical passage is formed through which recovery powder may fall by gravity from the cyclone separator (48) into the recovery powder storage container (40-2) ,
  • Powder spray coating system according to one of the preceding embodiments, characterized, in that the recovery powder storage container (48-2) has a container housing, which is a lower extension of the housing of the cyclone separator (48).
  • Powder spray coating system according to one of the preceding embodiments, characterized, in that the housing of the recovery powder storage container (48-2) is designed to be narrower from top to bottom in the shape of a truncated cone.
  • Powder spray coating system according to one of the preceding embodiments, characterized, in that the recovery powder storage container (48-2) is provided with a fluidizing device (66) for fluidizing the recovery powder present in the recovery powder storage container (48-2) by means of compressed air which is passed through the fluidizing device (66) into the recovery powder storage container (48). 2) can be introduced.
  • a fluidizing device (66) for fluidizing the recovery powder present in the recovery powder storage container (48-2) by means of compressed air which is passed through the fluidizing device (66) into the recovery powder storage container (48). 2 can be introduced.
  • a shut-off device (64), preferably in the form of at least one pinch valve, for the alternative shut-off or opening of a powder outlet (204), is provided at the lower end of the recovery powder storage container (48-2). at the lower end of the recovery powder reservoir (48-2) is provided.
  • Powder spray coating system according to one of the preceding embodiments, characterized, in that the at least one intermediate container sensor (S1, S2) and / or the at least one storage container sensor (S3, S4) are powder level sensors which generate said signal as a function of the powder level detected by them.
  • Powder spray coating system according to one of the preceding embodiments, characterized, in that the fresh powder supply device (70, 74) has a sensor device (76) which generates a first signal as a function of the quantity of fresh powder which is present in a fresh powder container (12) in the fresh powder supply device (70, 74), preferably at least whenever the amount of fresh powder in the fresh powder container (12) falls below a predetermined residual amount value.
  • Powder spray coating system characterized, in that the sensor device (76) of the fresh powder supply device (70, 74) is functionally connected to the at least one control device (3) and generates a second signal in the at least one control device when the fresh powder quantity in the fresh powder container (12) has dropped to a lower limit value which is a predetermined distance below the residual amount value at which said first signal is generated.
  • Powder spray coating system according to embodiment 10, characterized, the at least one control device (3), upon receiving the second signal of the sensor device (76) of the fresh powder supply device (70, 74), switches the powder spray coating system to a reserve operating phase if a powder demand signal is also generated by the at least one intermediate container sensor (S1) wherein during the reserve operation phase, only recovery powder from the powder reserve section (202) of the recovery powder storage tank (48-2) is supplied to the intermediate tank (24), but no fresh powder from the fresh powder supply device (70, 74).
  • the at least one control device (3) upon receiving the second signal of the sensor device (76) of the fresh powder supply device (70, 74), switches the powder spray coating system to a reserve operating phase if a powder demand signal is also generated by the at least one intermediate container sensor (S1) wherein during the reserve operation phase, only recovery powder from the powder reserve section (202) of the recovery powder storage tank (48-2) is supplied to the intermediate tank (24), but no fresh powder from the fresh powder supply device (70, 74).
  • Powder spray coating system characterized, in that the sensor device (76) of the fresh powder supply device (70, 74) is operatively connected to the at least one control device (3), and that the at least one control device (3) is designed such that it responds to the first signal from the Sensor device (76) of the fresh powder supply device (70, 74), the spray coating system switches to a reserve operating phase, when further a powder demand signal from the at least one surge tank sensor (S1) is generated, wherein in the reserve operating phase the intermediate container (24) only recovery powder from the Powder reserve portion (202) of the recovery powder storage container (48-2) is supplied, but no fresh powder from the fresh powder supply device (70, 74).
  • Powder spray coating system characterized, in that the sensor device (76) of the fresh powder supply device (70, 74) is functionally connected to the at least one control device (3), and that the at least one control device (3) is designed such that it responds on the first signal from the sensor device (76) of the fresh powder supply device (70, 74), the spray coating system switches to a reserve operating phase, when a powder demand signal from the at least one surge tank sensor (S1) is further generated, wherein in the reserve operating phase the intermediate tank ( 24) only recovery powder from the powder reserve section (202) of the recovery powder storage container (48-2) is supplied, but no fresh powder from the fresh powder supply device (70, 74), and wherein the control device (3) includes a time delay circuit, by which Switching to the reserve operating phase only after a predetermined time delay period after receipt of the first signal of the sensor device (76) of the fresh powder supply device (70, 74) is effected.
  • Powder spray coating system according to any one of embodiments 9 to 13, characterized, in that the sensor device (76) of the fresh powder supply device (70, 72) is a weighing device for weighing the weight of the fresh powder in a fresh powder container (12).
  • Powder spray coating system according to one of the preceding embodiments, characterized, in that a screening device (10) is arranged on the powder path of the recovery powder from the recovery powder storage container (48-2) to the intermediate container (24).
  • Powder spray coating system characterized, that the Frischpulverzubowweg from the fresh powder supply device (70, 74) to the intermediate container (24) through the sieve device (10), so that the fresh powder is sieved.
  • Powder spray coating system marked by a powder pump (4) in a preferably closed to the outside, Pulverwegabites (50) of the recovery powder from the recovery powder reservoir (48-2) to the input side of the screening device (10), preferably also the input side of the screening device against the outside atmosphere for coating powder closed is.
  • Powder spray coating system marked by a powder pump (4) in the at least one, preferably closed to the outside atmosphere, Pulverwegabites (16) of the fresh powder from the fresh powder container (12) of the fresh powder supply device (70, 74) to the input side of the screening device (10), preferably also the Input side of the screening device with respect to the coating powder against the outside atmosphere is closed.
  • Powder spray coating system marked by in each case a powder pump (4) in the at least one, preferably closed to the outside atmosphere, Pulverwegabites (20) from an output side of the screening device (10) in the intermediate container (24), preferably also the output side of the screening device (10) and the intermediate container (24 ) are closed to the outside atmosphere with respect to the coating powder.
  • Powder spray coating system according to at least one of the preceding embodiments, marked by in each case a powder pump (4) in the at least one powder path (38) of the coating powder from the intermediate container (24) to the at least one spray device (40).
  • Powder spray coating method in particular for operating the powder spray coating system according to one of the preceding embodiments, in which coating powder is pneumatically conveyed from an intermediate container (24) to at least one spray device (40); by means of at least one sensor (S1) on the intermediate container (24) a powder demand signal is generated when the powder level in the intermediate container (24) falls below a predetermined minimum powder level; using a cyclone separator (48), reclaiming recovery powder from an air stream containing sprayed excess powder which missed an object to be coated; in which Recovery powder is intermediately stored on the way from the cyclone separator (48) to the intermediate container (24) in a recovery powder reservoir (48-2), that by means of at least one reservoir sensor (S3), a recovery powder information signal is generated in dependence Powder level in Recovery Powder Reservoir (48-2) is below a minimum level or at least at the minimum level; that un-sprayed fresh powder from a fresh powder container (12) is supplied to the intermediate container (24) on a powder path which bypasses the cyclone separator (48)

Description

Die Erfindung betrifft eine Pulversprühbeschichtungsanlage gemäß dem Oberbegriff der unabhängigen Patentansprüche. Eine solche Anlage ist aus der CH 529 590 A bekannt.The invention relates to a powder spray coating system according to the preamble of the independent claims. Such a plant is from the CH 529 590 A known.

Pulversprühbeschichtungsanlagen sind beispielsweise aus der US 3 960 323 , US 3,918,641 , EP 0 412 289 B2 , DE 42 39 496 A1 und DE 103 53 968 A1 bekannt.Pulversprühbeschichtungsanlagen are for example from the US Pat. No. 3,960,323 . US 3,918,641 . EP 0 412 289 B2 . DE 42 39 496 A1 and DE 103 53 968 A1 known.

Durch die Erfindung soll die Aufgabe gelöst werden, Pulversprühbeschichtungsanlagen und Pulversprühbeschichtungsverfahren effizienter zu gestalten.The object of the invention is to achieve a more efficient powder spray coating and powder spray coating process.

Diese Aufgabe wird gemäß der Erfindung durch die Merkmale von Anspruch 1 oder durch die Merkmale von Anspruch 23 gelöst.This object is achieved according to the invention by the features of claim 1 or by the features of claim 23.

Weitere Merkmale der Erfindung sind in den Unteransprüchen enthalten.Further features of the invention are contained in the subclaims.

Die Erfindung wird im Folgenden mit Bezug auf die Zeichnungen anhand von bevorzugten Ausführungsformen als Beispiele beschrieben. In den Zeichnungen zeigen

Fig. 1
schematisch eine Pulversprühbeschichtungsanlage nach der Erfindung,
Fig. 2
schematisch und vergrößert ein Detail von Fig. 1.
The invention will now be described by way of example with reference to the drawings of preferred embodiments. In the drawings show
Fig. 1
schematically a powder spray coating system according to the invention,
Fig. 2
schematically and enlarged a detail of Fig. 1 ,

Fig. 1 zeigt schematisch eine bevorzugte Ausführungsform einer Pulversprühbeschichtungsanlage gemäß der Erfindung zum Sprühbeschichten von Objekten 2 mit Beschichtungspulver, welches danach in einem nicht gezeigten Wärmeofen auf das Objekt aufgeschmolzen wird. Für die Steuerung der Funktionen der Pulversprühbeschichtungsanlage sind ein oder mehrere elektronische Steuergeräte 3 vorgesehen. Zur pneumatischen Förderung des Beschichtungspulvers sind Pulverpumpen 4 vorgesehen. Dies können Injektoren sein, in welchen Beschichtungspulver mittels als Förderluft dienender Druckluft aus einem Pulverbehälter angesaugt wird, wonach dann das Gemisch aus Förderluft und Beschichtungspulver gemeinsam in einen Behälter oder zu einer Sprühvorrichtung strömt. Fig. 1 schematically shows a preferred embodiment of a powder spray coating system according to the invention for spray coating of objects 2 with coating powder, which is then melted in a furnace, not shown, on the object. One or more electronic control units 3 are provided for controlling the functions of the powder spray coating system. For pneumatic conveying of the coating powder powder pumps 4 are provided. These can be injectors, in which coating powder is sucked by means of compressed air serving as compressed air from a powder container, after which then the mixture of conveying air and coating powder flows together into a container or to a spraying device.

Injektoren sind z. B. aus der EP 0 412 289 B1 bekannt.Injectors are z. B. from the EP 0 412 289 B1 known.

Als Pulverpumpe können auch solche Pumpenarten verwendet werden, welche kleine Pulverportionen mittels Druckluft nacheinander fördern, wobei jeweils eine kleine Pulverportion (Pulvermenge) in einer Pulverkammer gespeichert und dann mittels Druckluft aus der Pulverkammer herausgedrückt wird. Die Druckluft bleibt hinter der Pulverportion und schiebt die Pulverportion vor sich her. Diese Pumpenarten werden manchmal als Druckluftschubpumpen oder als Pfropfenförderungs-Pumpen bezeichnet, da die Druckluft die gespeicherte Pulverportion wie einen Pfropfen vor sich her durch eine Pumpenauslassleitung schiebt. Verschiedene Arten solcher Pulverpumpen zum Fördern von dichtem Beschichtungspulver sind beispielsweise aus folgenden Schriften bekannt: DE 103 53 968 A1 , US 6,508,610 B2 , US 2006/0193704 A1 , DE 101 45 448 A1 , WO 2005/051549 A1 .As a powder pump and those types of pumps can be used which convey small portions of powder by means of compressed air in succession, each one small powder portion (powder) stored in a powder chamber and then pushed out of the powder chamber by means of compressed air. The compressed air remains behind the powder portion and pushes the powder portion in front of him. These types of pumps are sometimes referred to as pneumatic push pumps or plug-lift pumps because the compressed air pushes the stored powder portion through a pump outlet line like a plug. Various types of such powder pumps for conveying dense coating powder are known, for example, from the following documents: DE 103 53 968 A1 . US 6,508,610 B2 . US 2006/0193704 A1 . DE 101 45 448 A1 . WO 2005/051549 A1 ,

Die Erfindung ist nicht auf eine der genannten Arten von Pulverpumpen beschränkt.The invention is not limited to any of the mentioned types of powder pumps.

Zur Erzeugung der Druckluft für die pneumatische Förderung des Beschichtungspulvers und zur Fluidisierung des Beschichtungspulvers ist eine Druckluftquelle 6 vorgesehen, welche über entsprechende Druckeinstellelemente 8, z. B. Druckregler und/oder Ventile, an die verschiedenen Geräte angeschlossen ist.To generate the compressed air for the pneumatic conveying of the coating powder and for fluidizing the coating powder, a compressed air source 6 is provided, which via corresponding Druckeinstellelemente 8, z. B. pressure regulator and / or valves, is connected to the various devices.

Frischpulver von einem Pulverlieferanten wird aus einem Lieferantenbehältnis, was beispielsweise ein Kleinbehältnis 12 z. B. in Form eines formstabilen Behälters oder eines Sackes mit einer Pulvermenge von beispielsweise zwischen 10 bis 50 kg, z. B. 25 kg, oder z. B. ein Großbehältnis 14, beispielsweise ebenfalls ein formstabiler Behälter oder ein Sack, mit einer Pulvermenge zwischen beispielsweise 100 kg und 1000 kg sein kann, mittels einer Pulverpumpe 4 in einer Frischpulverleitung 16 oder 18 einer Siebvorrichtung 10 zugeführt. Die Siebvorrichtung 10 kann mit einem Vibrator 11 versehen sein. In der folgenden Beschreibung bedeuten die Ausdrücke "Kleinbehälter" und "Großbehälter" jeweils sowohl "formstabiler Behälter" als auch "nicht formstabiler, flexibler Sack", ausgenommen wenn ausdrücklich auf die eine oder die andere Behältnisart verwiesen wird.Fresh powder from a powder supplier is from a supplier container, which, for example, a small container 12 z. B. in the form of a dimensionally stable container or a bag with a powder amount of, for example, between 10 to 50 kg, z. B. 25 kg, or z. B. a large container 14, for example, also a dimensionally stable container or bag, with a powder amount between, for example, 100 kg and 1000 kg may be supplied by means of a powder pump 4 in a fresh powder line 16 or 18 of a screening device 10. The screening device 10 may be provided with a vibrator 11. In the following description, the terms "small container" and "large container" respectively mean both "dimensionally stable container" and "non-dimensionally stable, flexible bag", except where expressly referred to one or the other Behältnisart.

Das von der Siebvorrichtung 10 gesiebte Beschichtungspulver wird durch Schwerkraft oder vorzugsweise jeweils durch eine Pulverpumpe 4 über eine oder mehrere Pulverzufuhrleitungen 20 durch Pulvereinlassöffnungen 26 in eine Zwischenbehälterkammer 22 eines formstabilen Zwischenbehälters 24 gefördert. Das Volumen der Zwischenbehälterkammer 22 ist vorzugsweise wesentlich kleiner als das Volumen des Frischpulver-Kleinbehälters 12.The coating powder sieved by the sieve device 10 is conveyed by gravity or preferably in each case by a powder pump 4 via one or more powder feed lines 20 through powder inlet openings 26 into an intermediate container chamber 22 of a dimensionally stable intermediate container 24. The volume of the intermediate container chamber 22 is preferably substantially smaller than the volume of the fresh powder small container 12.

Gemäß einer bevorzugten Ausführungsform der Erfindung ist die Pulverpumpe 4 der mindestens einen Pulverzufuhrleitung 20 zu dem Zwischenbehälter 24 eine Druckluftschubpumpe. Hierbei kann der Anfangsabschnitt der Pulverzufuhrleitung 20 als Pumpenkammer dienen, in welche von der Siebvorrichtung 10 gesiebtes Pulver durch ein Ventil, z. B. ein Quetschventil, fällt. Nachdem diese Pumpenkammer eine bestimmte Pulverportion enthält, wird die Pulverzufuhrleitung 20 durch Schließen des Ventils von der Siebvorrichtung 10 strömungsmäßig getrennt. Danach wird die Pulverportion mittels Druckluft durch die Pulverzufuhrleitung 20 in die Zwischenbehälterkammer 20 gestoßen.According to a preferred embodiment of the invention, the powder pump 4 of the at least one powder supply line 20 to the intermediate container 24 is a compressed air push pump. Here, the initial portion of the powder supply line 20 may serve as a pump chamber, in which sieved by the sieve 10 powder through a valve, for. B. a pinch valve falls. After this pump chamber contains a certain powder portion, the powder supply line 20 is fluidly separated by closing the valve of the sieve device 10. After that, the Powder portion pushed by compressed air through the powder supply line 20 into the intermediate container chamber 20.

Die Pulvereinlassöffnungen 26 sind vorzugsweise in einer Seitenwand des Zwischenbehälters 24, vorzugsweise nahe des Bodens der Zwischenbehälterkammer 22 angeordnet, sodass beim Durchspülen der Zwischenbehälterkammer 22 mittels Druckluft auch am Boden befindliche Pulverreste durch die Pulvereinlassöffnungen 26 hinausgetrieben werden können, zu welchem Zwecke die Pulverzufuhrleitungen 20 vorzugsweise von der Siebvorrichtung 10 getrennt und in einen Abfallbehälter gerichtet werden, wie dies in Fig. 1 schematisch durch einen gestrichelten Pfeil 28 angedeutet ist. Zum Reinigen der Zwischenbehälterkammer 22 ist beispielsweise ein mit Druckluftdüsen versehener Tauchkolben 30 durch die Zwischenbehälterkammer 22 hindurch bewegbar.The powder inlet openings 26 are preferably arranged in a side wall of the intermediate container 24, preferably near the bottom of the intermediate container chamber 22, so that when flushing the intermediate container chamber 22 by means of compressed air also on the ground located powder residues can be driven out through the powder inlet openings 26, for which purpose the powder supply lines 20 preferably from the screening device 10 are separated and directed into a waste container, as in Fig. 1 is indicated schematically by a dashed arrow 28. For cleaning the intermediate container chamber 22, for example, a plunger 30 provided with compressed-air nozzles can be moved through the intermediate container chamber 22.

An ein oder vorzugsweise mehrere Pulverauslassöffnungen 36 sind Pulverpumpen 4, z. B. Injektoren, zur Förderung von Beschichtungspulver durch Pulverleitungen 38 zu Sprühvorrichtungen 40 angeschlossen. Die Sprühvorrichtungen 40 können Sprühdüsen oder Rotationszerstäuber zum Sprühen des Beschichtungspulvers 42 auf das zu beschichtende Objekt 2 aufweisen, welches sich vorzugsweise in einer Beschichtungskabine 43 befindet. Die Pulverauslassöffnungen 36 befinden sich vorzugsweise in einer Wand, welche der Wand gegenüberliegt, in welcher sich die Pulvereinlassöffnungen 26 befinden. Die Pulverauslassöffnungen 36 sind vorzugsweise ebenfalls nahe des Bodens der Zwischenbehälterkammer 22 angeordnet.At one or preferably more Pulverauslassöffnungen 36 are powder pumps 4, z. B. injectors, connected to spray devices 40 for conveying coating powder through powder lines 38. The spray devices 40 may include spray nozzles or rotary atomizers for spraying the coating powder 42 onto the object 2 to be coated, which is preferably located in a coating booth 43. The powder outlet openings 36 are preferably located in a wall opposite the wall in which the powder inlet openings 26 are located. The powder outlet openings 36 are preferably also located near the bottom of the intermediate container chamber 22.

Die Zwischenbehälterkammer 22 hat vorzugsweise eine Größe, die im Bereich eines Fassungsvermögens an Beschichtungspulver zwischen 1,0 kg und 12 kg liegt, vorzugsweise zwischen 2,0 kg und 8,0 kg. Gemäß anderen Gesichtspunkten beträgt die Größe der Zwischenbehälterkammer 22 vorzugsweise zwischen 500 cm3 und 30 000 cm3, vorzugsweise zwischen 2000 cm3 und 20 000 cm3. Die Größe der Zwischenbehälterkammer 22 wird in Abhängigkeit von der Anzahl der Pulverauslassöffnungen 36 und der daran angeschlossenen Pulverleitungen 38 derart gewählt, dass ein kontinuierlicher Sprühbeschichtungsbetrieb möglich ist, jedoch die Zwischenbehälterkammer 22 in Beschichtungspausen für einen Pulverwechsel schnell gereinigt werden kann, vorzugsweise automatisch. Die Zwischenbehälterkammer 22 kann mit einer Fluidisiervorrichtung zum Fluidisieren des Beschichtungspulvers versehen werden.The tundish chamber 22 preferably has a size which is within the range of a capacity of coating powder between 1.0 kg and 12 kg, preferably between 2.0 kg and 8.0 kg. In other aspects, the size of the intermediate reservoir chamber 22 is preferably between 500 cm 3 and 30 000 cm 3 , preferably between 2000 cm 3 and 20 000 cm 3 . The size of the intermediate container chamber 22 is selected in dependence on the number of powder outlet openings 36 and the powder lines 38 connected thereto in such a way that a continuous spray coating operation is possible, However, the intermediate container chamber 22 can be cleaned quickly in coating pauses for a powder change, preferably automatically. The intermediate container chamber 22 may be provided with a fluidizing device for fluidizing the coating powder.

Beschichtungspulver 42, welches nicht an dem Objekt 2 haftet, wird als Überschusspulver über eine Überschusspulverleitung 44 mittels eines Saugluftstroms eines Gebläses 46 in einen Zyklonabscheider 48 gesaugt. Das Überschusspulver wird im Zyklonabscheider 48 so weit wie möglich vom Saugluftstrom getrennt. Der getrennte Pulveranteil wird dann als Rückgewinnungspulver vom Zyklonabscheider 48 über eine Pulverrückgewinnungsleitung 50 zu der Siebvorrichtung 10 geleitet, wo es durch die Siebvorrichtung 10 hindurch, entweder allein oder vermischt mit Frischpulver, über die Pulverzufuhrleitungen 20 wieder in die Zwischenbehälterkammer 22 gelangt.Coating powder 42, which does not adhere to the object 2, is sucked as excess powder via a surplus powder line 44 into a cyclone separator 48 by means of a suction air flow of a blower 46. The excess powder is separated in Zyklonabscheider 48 as far as possible from the suction air stream. The separated powder portion is then passed as a recovery powder from the cyclone 48 via a powder recovery line 50 to the sifter 10, where it passes through the sifter 10, either alone or mixed with fresh powder via the powder supply lines 20 back into the intermediate container chamber 22.

Je nach Pulversorte und/oder Pulververschmutzungsgrad kann auch die Möglichkeit vorgesehen werden, die Pulverrückgewinnungsleitung 50 von der Siebvorrichtung 10 zu trennen und das Rückgewinnungspulver in einen Abfallbehälter zu leiten, wie dies in Fig. 1 durch eine gestrichelte Linie 51 schematisch dargestellt ist. Die Pulverrückgewinnungsleitung 50 kann, damit sie nicht von der Siebvorrichtung 10 getrennt zu werden braucht, mit einer Weiche 52 versehen werden, an welcher sie alternativ mit der Siebvorrichtung 10 oder mit einem Abfallbehälter verbindbar ist.Depending on the type of powder and / or degree of powder contamination, it may also be possible to separate the powder recovery line 50 from the screening device 10 and to pass the recovery powder into a waste container, as shown in FIG Fig. 1 is shown schematically by a dashed line 51. The powder recovery line 50, in order not to be separated from the screening device 10, may be provided with a switch 52, to which it is alternatively connectable to the screening device 10 or to a waste container.

Der Zwischenbehälter 24 kann einen oder mehrere, beispielsweise zwei Sensoren S1 und/oder S2 aufweisen, um die Zufuhr von Beschichtungspulver in die Zwischenbehälterkammer 22 mittels des Steuergerätes 3 und der Pulverpumpen 4 in den Pulverzuleitungen 20 zu steuern. Beispielsweise detektiert der untere Sensor S1 ein unteres Pulverniveaulimit und der obere Sensor S2 ein oberes Pulverniveaulimit.The intermediate container 24 may have one or more, for example two sensors S1 and / or S2, in order to control the supply of coating powder into the intermediate container chamber 22 by means of the control unit 3 and the powder pumps 4 in the powder feed lines 20. For example, the lower sensor S1 detects a lower powder level limit and the upper S2 sensor detects an upper powder level limit.

Der untere Endabschnitt 48-2 des Zyklonabscheiders 48 kann als Vorratsbehälter für Rückgewinnungspulver ausgebildet und verwendet werden und hierfür mit einem oder mehreren, beispielsweise zwei Sensoren S3 und/oder S4 versehen werden, welche funktionsmäßig mit dem Steuergerät 3 verbunden sind. Dadurch kann beispielsweise automatisch die Frischpulverzufuhr durch die Frischpulverzuleitungen 16 und 18 gestoppt werden, solange im Zyklonabscheider 48 ausreichend Rückgewinnungspulver vorhanden ist, um der Zwischenbehälterkammer 22 durch die Siebvorrichtung 10 hindurch Rückgewinnungspulver in ausreichender Menge zuzuführen, welche für den Sprühbeschichtungsbetrieb mittels der Sprühvorrichtungen 40 erforderlich ist. Wenn im Zyklonabscheider 48 hierfür nicht mehr ausreichend Rückgewinnungspulver vorhanden ist, dann kann automatisch auf die Zufuhr von Frischpulver durch die Frischpulverzuleitungen 16 oder 18 umgeschaltet werden. Ferner besteht auch die Möglichkeit, Frischpulver und Rückgewinnungspulver gleichzeitig der Siebvorrichtung 10 zuzuführen, sodass sie miteinander vermischt werden.The lower end portion 48-2 of the cyclone 48 may be formed and used as a reservoir for recovery powder and provided with one or more, for example, two sensors S3 and / or S4, which are functionally connected to the control unit 3. This can For example, the fresh powder feed through the fresh powder feed lines 16 and 18 are automatically stopped as long as there is sufficient recovery powder in the cyclone separator 48 to supply the intermediate tank chamber 22 through the sieve apparatus 10 with recovery powder in a sufficient amount required for the spray coating operation by means of the spray devices 40. If there is no longer sufficient recovery powder in the cyclone separator 48, then the supply of fresh powder through the fresh powder supply lines 16 or 18 can be switched over automatically. Furthermore, it is also possible to feed fresh powder and recovery powder simultaneously to the sieve device 10 so that they are mixed together.

Die Abluft des Zyklonabscheiders 48 gelangt über eine Abluftleitung 54 in eine Nachfiltervorrichtung 56 und darin durch ein oder mehrere Filterelemente 58 zu dem Gebläse 46 und nach diesem in die Außenatmosphäre. Die Filterelemente 58 können Filtersäcke oder Filterpatronen oder Filterplatten oder ähnliche Filterelemente sein. Das mittels der Filterelemente 58 vom Luftstrom getrennte Pulver ist normalerweise Abfallpulver und fällt durch Schwerkraft in einen Abfallbehälter oder kann, wie Fig. 1 zeigt, über eine oder mehrere Abfallleitungen 60, welche jeweils eine Pulverpumpe 4 enthalten, in einen Abfallbehälter 62 an einer Abfallstation 63 gefördert werden.The exhaust air of the cyclone 48 passes through an exhaust duct 54 in a Nachfiltervorrichtung 56 and therein by one or more filter elements 58 to the fan 46 and after this in the outside atmosphere. The filter elements 58 may be filter bags or filter cartridges or filter plates or similar filter elements. The separated by the filter elements 58 from the air flow powder is usually waste powder and falls by gravity into a waste container or can, such as Fig. 1 shows, via one or more waste lines 60, each containing a powder pump 4, are conveyed into a waste container 62 at a waste station 63.

Je nach Pulverart und Pulverbeschichtungsbedingungen kann das Abfallpulver auch wieder zurückgewonnen werden zur Siebvorrichtung 10, um erneut in den Beschichtungskreislauf zu gelangen. Dies ist in Fig. 1 durch Weichen 59 und Zweigleitungen 61 der Abfallleitungen 60 schematisch dargestellt.Depending on the powder type and powder coating conditions, the waste powder may also be recovered to the screening device 10 to re-enter the coating circuit. This is in Fig. 1 represented by switches 59 and branch lines 61 of the waste lines 60 schematically.

Beim Mehrfarbenbetrieb, bei welchem verschiedene Farben jeweils nur kurze Zeit versprüht werden, werden üblicherweise der Zyklonabscheider 48 und die Nachfiltervorrichtung 56 verwendet und das Abfallpulver der Nachfiltervorrichtung 56 gelangt in den Abfallbehälter 62. Der Pulverabscheide-Wirkungsgrad des Zyklonabscheiders 48 ist zwar meistens geringer als der der Nachfiltervorrichtung 56, jedoch kann er schneller gereinigt werden als die Nachfiltervorrichtung 56. Beim Einfarbenbetrieb, bei welchem für lange Zeit das gleiche Pulver verwendet wird, ist es möglich, auf den Zyklonabscheider 48 zu verzichten und die Überschusspulverleitung 44 anstelle der Abluftleitung 54 an die Nachfiltervorrichtung 56 anzuschließen und die Abfallleitungen 60, welche in diesem Fall zurückzugewinnendes Pulver enthalten, als Rückgewinnungspulverleitungen an die Siebvorrichtung 10 anzuschließen. Beim Einfarbenbetrieb wird üblicherweise nur dann der Zyklonabscheider 48 in Kombination mit der Nachfiltervorrichtung 56 verwendet, wenn es sich um ein problematisches Beschichtungspulver handelt. In diesem Fall wird nur das Rückgewinnungspulver des Zyklonabscheiders 48 über die Pulverrückgewinnungsleitung 50 der Siebvorrichtung 10 zugeführt, während das Abfallpulver der Nachfiltervorrichtung 56 als Abfall in den Abfallbehälter 62 oder in einen anderen Abfallbehälter gelangt, welch letzterer ohne Abfallleitungen 60 direkt unter eine Auslassöffnung der Nachfiltervorrichtung 56 gestellt werden kann.In multi-color operation in which different colors are sprayed only for a short time, usually the cyclone 48 and the Nachfiltervorrichtung 56 are used and the waste powder of the Nachfiltervorrichtung 56 enters the waste container 62. The powder separation efficiency of the cyclone 48 is indeed usually lower than that of After-filter device 56, however, it can be cleaned faster than the Nachfiltervorrichtung 56. In single-color operation, in which the same powder is used for a long time, is it is possible to dispense with the cyclone separator 48 and connect the excess powder pipe 44 to the afterfilter device 56 instead of the exhaust pipe 54 and connect the waste pipes 60 containing powder to be recovered in this case to the screening apparatus 10 as recovery powder pipes. In single-color operation, cyclone separator 48 is usually used in combination with post-filter device 56 only if it is a problematic coating powder. In this case, only the recovery powder of the cyclone 48 is supplied via the powder recovery line 50 of the sieve 10, while the waste powder of the Nachfiltervorrichtung 56 as waste in the waste container 62 or in another waste container, the latter without waste lines 60 directly below an outlet opening of the Nachfiltervorrichtung 56th can be made.

Das untere Ende der Zyklonvorrichtung 48 kann ein Auslassventil 64, beispielsweise ein Quetschventil aufweisen. Ferner kann oberhalb von diesem Auslassventil 64, im oder am unteren Ende des, als Vorratsbehälter ausgebildeten, unteren Endabschnittes 48-2 des Zyklonabscheiders 48, eine Fluidisiervorrichtung 66 zur Fluidisierung des Beschichtungspulvers vorgesehen sein. Die Fluidisiervorrichtung 66 enthält mindestens eine Fluidisierwand 80 aus einem offenporigem oder mit engen Bohrungen versehenen Material, welches für Druckluft, jedoch nicht für Beschichtungspulver durchlässig ist. Die Fludisierwand 80 ist zwischen dem Pulverweg und einer Fluidiesier-Druckluftkammer 81 angeordnet. Die Fluidisier-Druckluftkammer 81 ist über ein Druckeinstellelement 8 mit der Druckluftquelle 6 verbindbar.The lower end of the cyclone device 48 may include an outlet valve 64, such as a pinch valve. Furthermore, a fluidizing device 66 for fluidizing the coating powder may be provided above this outlet valve 64, in or at the lower end of the, designed as a reservoir, lower end portion 48-2 of the cyclone 48. The fluidizing device 66 includes at least one fluidising wall 80 of an open-pore or narrow-bore material which is pervious to compressed air but not to coating powder. The fluidizing wall 80 is disposed between the powder path and a fluidizing compressed air chamber 81. The fluidizing compressed-air chamber 81 can be connected to the compressed-air source 6 via a pressure-adjusting element 8.

Die Frischpulverleitung 16 und/oder 18 kann an ihrem stromaufwärtigen Ende, entweder direkt oder durch die Pulverpumpe 4, mit einem Pulverförderrohr 70 strömungsmäßig verbunden sein, welches in den Lieferantenbehälter 12 oder 14 eintauchbar ist zum Absaugen von frischem Beschichtungspulver. Die Pulverpumpe 4 kann am Anfang, am Ende oder dazwischen in der Frischpulverleitung 16 bzw. 18 oder am oberen oder unteren Ende des Pulverförderrohres 70 angeordnet werden.The fresh powder line 16 and / or 18 may be fluidly connected at its upstream end, either directly or through the powder pump 4, to a powder delivery tube 70 which is submerged in the supplier vessel 12 or 14 for aspiration of fresh coating powder. The powder pump 4 may be disposed at the beginning, at the end or in between in the fresh powder line 16 or 18 or at the upper or lower end of the powder conveying tube 70.

Fig. 1 zeigt als Frischpulver-Kleinbehälter einen Frischpulver-Pulversack 12 in einem Sackaufnahmetrichter 74. Der Pulversack 12 wird von dem Sackaufnahmetrichter 74 in einer definierten Form gehalten, wobei die Sacköffnung sich am oberen Sackende befindet. Der Sackaufnahmetrichter 74 kann auf einer Waage oder Wägesensoren 76 angeordnet werden. Diese Waage oder die Wägesensoren können, je nach Art, eine optische Anzeige und/oder ein elektrisches Signal erzeugen, welches nach Abzug des Gewichts des Sackaufnahmetrichters 74 dem Gewicht und damit auch der Menge des Beschichtungspulvers in dem Kleinbehälter 12 entspricht. Am Sackaufnahmetrichter 74 ist vorzugsweise mindestens ein ihn vibrierender Vibrator 78 angeordnet. Fig. 1 shows as fresh powder small container a fresh powder powder bag 12 in a bag receiving hopper 74. The powder bag 12 is held by the bag receiving hopper 74 in a defined shape, the bag opening is located at the upper bag end. The bag receiving hopper 74 may be disposed on a scale or weighing sensors 76. Depending on the type, this balance or the weighing sensors can generate an optical display and / or an electrical signal which, after subtracting the weight of the bag receiving hopper 74, corresponds to the weight and thus also the amount of the coating powder in the small container 12. At the bag receiving hopper 74, at least one vibrator 78 vibrating it is preferably arranged.

Es können zwei oder mehr Kleinbehälter 12 jeweils in einem Sackaufnahmetrichter 74 und/oder zwei oder mehr Grossbehältnisse 14 vorgesehen werden, die alternativ benutzbar sind. Dadurch ist ein schneller Wechsel von einem auf einen anderen Kleinbehälter 12 oder Grossbehältnis 14 möglich.Two or more small containers 12 can each be provided in a bag receiving hopper 74 and / or two or more large containers 14, which can be used alternatively. As a result, a quick change from one to another small container 12 or large container 14 is possible.

Mögliche Varianten der Erfindung, ohne darauf beschränkt zu sein: die Siebvorrichtung 10 kann in den Zwischenbehälter 24 integriert werden. Ferner kann die Siebvorrichtung 10 weggelassen werden, wenn das Frischpulver eine ausreichend gute Qualität hat. In diesem Fall besteht ferner die Möglichkeit, zum Sieben des Rückgewinnungspulvers der Leitungen 44 und 50 ein separates Sieb zu verwenden, z. B. stromaufwärts oder stromabwärts des Zyklonabschalters 48 oder im Zyklonabschalter 48. Auch das Rückgewinnungspulver benötigt dann kein Sieb, wenn seine Pulverqualität für eine Wiederverwendung ausreichend gut ist.Possible variants of the invention, without being limited thereto: the screening device 10 can be integrated into the intermediate container 24. Furthermore, the screening device 10 can be omitted if the fresh powder has a sufficiently good quality. In this case, it is also possible to use for sieving the recovery powder of the lines 44 and 50, a separate sieve, z. Upstream or downstream of the cyclone shut-off 48 or in the cyclone shut-off 48. Also, the recovery powder will not require a sieve if its powder grade is sufficiently good for reuse.

Fig. 2 zeigt, gegenüber Fig. 1 vergrößert, die Fluidisiervorrichtung 66. Sie enthält die für Druckluft durchlässige, jedoch für Beschichtungspulver undurchlässige Fluidisierwand 80 zwischen dem Pulverweg am unteren Ende des Vorratsbehälters 48-2 und der Fluidisier-Druckluftkammer 81, welche sich über die Fludisierwand 80 erstreckt. Druckluft der Druckluftquelle 6 gelangt über ein Steuerelement 8, z. B. ein Ventil und/oder ein Druckregler, in die Fluidisier-Druckluftkammer 81 und von dieser durch Poren oder eine Vielzahl von sehr enge Bohrungen der Fluidisierwand 80 in den unteren Endteil des als Vorratsbehälter ausgebildeten Endabschnittes 48-2 des Zyklonabscheiders 48. Die Fluidisierwand 80 kann das untere Ende des Endabschnittes 48-2 über einem Pulverauslass 204 des Endabschnittes 48-2 vollständig oder teilweise bilden. Über den Umfang des als Vorratsbehälter ausgebildeten Endabschnittes 48-2 können zwei oder mehr Fluidisierwände 80 und Fluidisier-Druckluftkammern 81 verteilt angeordnet werden. Das Auslassventil 64 hat einen vertikalen Abstand 202 von dem Messniveau des oberen Sensors S3 und einen vertikalen Abstand 206 von dem Messniveau des unteren Sensors S4 des Endabschnittes 48-2. Das Volumen des als Vorratsbehälter dienenden Endabschnittes 48-2 zwischen den beiden Sensoren S3 und S4 definiert ein vorbestimmtes Reservevolumen für Rückgewinnungspulver. Fig. 2 shows, opposite Fig. 1 It contains the pressurized air permeable but coating powder impermeable fluidizing wall 80 between the powder path at the lower end of the reservoir 48-2 and the fluidizing pressurized air chamber 81 extending above the fluidizing wall 80. Compressed air of the compressed air source 6 passes through a control 8, z. As a valve and / or a pressure regulator, in the fluidizing compressed air chamber 81 and from there through pores or a plurality of very narrow holes of the fluidizing wall 80 in the lower end portion of the container formed as a reservoir end portion 48-2 of the cyclone 48. Die Fluidisierwand 80 can the lower end of the Form end portion 48-2 over a powder outlet 204 of the end portion 48-2 completely or partially. Two or more fluidizing walls 80 and fluidizing compressed air chambers 81 can be distributed over the circumference of the end portion 48-2 formed as a reservoir. The exhaust valve 64 has a vertical distance 202 from the measurement level of the upper sensor S3 and a vertical distance 206 from the measurement level of the lower sensor S4 of the end portion 48-2. The volume of the reservoir-serving end portion 48-2 between the two sensors S3 and S4 defines a predetermined reserve volume for recovery powder.

Einzelne Elemente und Unterkombinationen von Elementen von Fig. 1 und Fig. 2 sowie der hier gegebenen Beschreibung sind jeweils auch selbstständig ohne die betreffenden anderen Elemente vorteilhaft verwendbar. Im Folgenden werden besonders bevorzugte Ausführungsformen der Erfindung beschrieben.Individual elements and subcombinations of elements of Fig. 1 and Fig. 2 as well as the description given here are each independently also advantageously usable without the other elements concerned. In the following, particularly preferred embodiments of the invention will be described.

Ausführungsform 1:Embodiment 1:

Pulversprühbeschichtungsanlage, enthaltend einen Zwischenbehälter (24), aus welchem Beschichtungspulver zu mindestens einer Sprühvorrichtung (40) pneumatisch förderbar ist; mindestens einen Sensor (S1) am Zwischenbehälter (24) zur Erzeugung eines Pulverbedarfssignals, wenn das Pulverniveau im Zwischenbehälter (24) ein vorbestimmtes Pulvermindestniveau unterschritten hat; einen Zyklonabscheider (48) zum Abscheiden von Rückgewinnungspulver aus einem Luftstrom welcher versprühtes Überschusspulver enthält, welches ein zu beschichtendes Objekt verfehlte;
wobei,
ein Rückgewinnungspulver-Vorratsbehälter (48-2) auf dem Weg des Rückgewinnungspulvers vom Zyklonabscheider (48) zu dem Zwischenbehälter (24) angeordnet ist zur Zwischenspeicherung des Rückgewinnungspulvers im Rückgewinnungspulver-Vorratsbehälter (48-2), bevor es dem Zwischenbehälter (24) zugeführt wird; dass der Rückgewinnungspulver-Vorratsbehälter (48-2) mit mindestens einem Vorratsbehälter-Sensor (S3) versehen ist zur Erzeugung eines Rückgewinnungspulver-Informationssignals in Abhängigkeit davon, ob das Pulverniveau unter einem Mindestniveau oder mindestens auf dem Mindestniveau ist; dass eine Frischpulver-Versorgungsvorrichtung (70, 74) vorgesehen ist zur Zufuhr von unversprühtem Frischpulver aus einem Frischpulverbehälter (12; 14) in den Zwischenbehälter (24) auf mindestens einem Pulverweg, welcher unter Umgehung des Zyklonabscheiders (48) und auch unter Umgehung des Rückgewinnungspulver-Vorratsbehälters (48-2) verläuft; dass mindestens ein Steuergerät (3) vorgesehen ist, welches mit den Sensoren (S1, S3) funktionsmäßig verbunden und zur automatischen Steuerung der Pulversprühbeschichtungsanlage derart ausgebildet ist, dass gemäß einer ersten Betriebsphase dem Zwischenbehälter (24) nur Rückgewinnungspulver aus dem Rückgewinnungspulver-Vorratsbehälter (48-2) zugeführt wird, jedoch kein Frischpulver von der Frischpulver-Versorgungsvorrichtung (70, 74), wenn vom Zwischenbehälter-Sensor (S1) ein Pulverbedarfsignal und gleichzeitig vom Rückgewinnungspulver-Vorratsbehälter-Sensor (S3) ein Rückgewinnungspulver-Informationssignal vorliegt, welch letzteres einem auf oder über dem vorbestimmten Mindestniveau liegenden Rückgewinnungspulverniveau entspricht, jedoch in einer zweiten Betriebsphase dem Zwischenbehälter (24) nur Frischpulver von der Frischpulver-Versorgungsvorrichtung (70, 74) zugeführt wird, jedoch kein Rückgewinnungspulver aus dem Rückgewinnungspulver-Vorratsbehälter (48-2), wenn vom Zwischenbehälter-Sensor (S1) ein Pulverbedarfsignal und gleichzeitig vom Vorratsbehälter-Sensor (S3) ein Rückgewinnungspulver-Informationssignal vorliegt, welch letzteres einem unter dem Mindestniveau liegenden Rückgewinnungspulverniveau entspricht, und wobei
der mindestens eine Vorratsbehälter-Sensor (S3) so hoch am Rückgewinnungspulver-Vorratsbehälter (48-2) angeordnet ist, dass der Rückgewinnungspulver-Vorratsbehälter (48-2) unterhalb des Vorratsbehälter-Sensors (S3) einen Pulverreserveabschnitt (202) hat, in welchem eine vorbestimmte Rückgewinnungspulver-Reservemenge speicherbar ist, die bis zu dem Mindestniveau reicht.Powder spray coating system, comprising an intermediate container (24), from which coating powder is pneumatically conveyable to at least one spray device (40); at least one sensor (S1) on the intermediate container (24) for generating a powder requirement signal when the powder level in the intermediate container (24) has fallen below a predetermined minimum powder level; a cyclone separator (48) for separating recovery powder from a stream of air containing sprayed excess powder which missed an object to be coated;
in which,
a recovery powder reservoir (48-2) is disposed on the way of the recovery powder from the cyclone separator (48) to the intermediate container (24) for temporarily storing the recovery powder in the recovery powder storage container (48-2) before being supplied to the intermediate container (24) ; in that the recovery powder storage container (48-2) is provided with at least one storage tank sensor (S3) for generating a recovery powder information signal in dependence on whether the powder level is below a minimum level or at least at the minimum level is; in that a fresh powder supply device (70, 74) is provided for supplying fresh powder powder from a fresh powder container (12, 14) into the intermediate container (24) on at least one powder path which bypasses the cyclone separator (48) and also bypasses the recovery powder Storage tank (48-2) runs; in that at least one control device (3) is provided, which is functionally connected to the sensors (S1, S3) and designed for automatic control of the powder spray coating system such that only recovery powder from the recovery powder storage container (48) is provided to the intermediate container (24) according to a first operating phase -2), but no fresh powder from the fresh powder supply device (70, 74), when there is a powder demand signal from the tundish sensor (S1) and a recovery powder information signal from the recovery powder hopper sensor (S3), the latter one However, in a second phase of operation, only fresh powder from the fresh powder supply device (70, 74) is supplied to the intermediate container (24), but no recovery powder from the recovery powder supply container (48-2), we nn from the surge tank sensor (S1) a powder demand signal and at the same time from the hopper sensor (S3) a recovery powder information signal is present, the latter corresponds to a below the minimum level recovery powder level, and wherein
the at least one reservoir sensor (S3) is located high enough on the recovery powder reservoir (48-2) such that the recovery powder reservoir (48-2) below the reservoir sensor (S3) has a powder reserve section (202) in which a predetermined recovery powder reserve amount can be stored, which reaches up to the minimum level.

dadurch gekennzeichnet,
dass das mindestens eine Steuergerät (3) zur automatischen Umschaltung der Pulversprühbeschichtungsanlage von der zweiten Betriebsphase auf eine Reservebetriebsphase ausgebildet ist, bei welcher dem Zwischenbehälter (24) nur Rückgewinnungspulver aus dem Pulverreserveabschnitt (202) des Rückgewinnungspulver-Vorratsbehälters (48-2) zugeführt wird, jedoch kein Frischpulver von der Frischpulver-Versorgungsvorrichtung (70, 74), wenn nach einer vorbestimmten Verzögerungszeit nach dem Umschalten von der ersten Betriebsphase auf die zweite Betriebsphase weiterhin vom Zwischenbehälter-Sensor (S1) ein Pulverbedarfsignal vorliegt, wobei das mindestens eine Steuergerät (3) eine Verzögerungsschaltung enthält, welche die Verzögerungszeit definiert oder an welcher die Verzögerungszeit variabel einstellbar ist.characterized,
in that the at least one control unit (3) for automatic switching of the powder spray coating plant from the second operating phase to a reserve operating phase is formed, in which only recovery powder from the powder reserve section (202) of the recovery powder storage tank (48-2) is fed to the intermediate tank (24), However, no fresh powder from the fresh powder supply device (70, 74), if after a predetermined delay time after switching from the first phase of operation to the second phase of operation further from the tundish sensor (S1) a powder demand signal is present, said at least one control unit (3) contains a delay circuit which defines the delay time or at which the delay time is variably adjustable.

Ausführungsform 2:Embodiment 2:

Pulversprühbeschichtungsanlage nach Ausführungsform 1,
dadurch gekennzeichnet,
dass der Rückgewinnungspulver-Vorratsbehälter (48-2) mit einem zweiten Vorratsbehälter-Sensor (S4) versehen ist zur Erzeugung eines Notsignals jeweils dann, wenn das Rückgewinnungspulverniveau im Rückgewinnungspulver-Vorratsbehälter (48-2) auf ein vorbestimmtes unteres Grenzniveau abgesunken ist, welches mit einem vorbestimmten Abstand unter dem vorbestimmten Rückgewinnungspulver-Mindestniveau des ersten Vorratsbehälter-Sensors (S3) liegt.Powder spray coating system according to embodiment 1,
characterized,
the recovery powder reservoir (48-2) is provided with a second reservoir sensor (S4) for generating a distress signal each time the recovery powder level in the recovery powder reservoir (48-2) has dropped to a predetermined lower limit level a predetermined distance below the predetermined recovery powder minimum level of the first reservoir sensor (S3).

Ausführungsform 3:Embodiment 3:

Pulversprühbeschichtungsanlage nach einer der vorhergehenden Ausführungsformen,
dadurch gekennzeichnet,
dass der Rückgewinnungspulver-Vorratsbehälter (48-2) unter dem Zyklonabscheider (48) angeordnet ist und zwischen ihnen ein vertikaler Durchgang gebildet ist, durch welchen Rückgewinnungspulver durch Schwerkraft von dem Zyklonabscheider (48) in den Rückgewinnungspulver-Vorratsbehälter (40-2) fallen kann.Powder spray coating system according to one of the preceding embodiments,
characterized,
that the recovery powder storage container (48-2) is disposed below the cyclone separator (48) and between which a vertical passage is formed through which recovery powder may fall by gravity from the cyclone separator (48) into the recovery powder storage container (40-2) ,

Ausführungsform 4:Embodiment 4:

Pulversprühbeschichtungsanlage nach einer der vorhergehenden Ausführungsformen,
dadurch gekennzeichnet,
dass der Rückgewinnungspulver-Vorratsbehälter (48-2) ein Behältergehäuse hat, welches eine untere Verlängerung des Gehäuses des Zyklonabscheiders (48) ist.Powder spray coating system according to one of the preceding embodiments,
characterized,
in that the recovery powder storage container (48-2) has a container housing, which is a lower extension of the housing of the cyclone separator (48).

Ausführungsform 5:Embodiment 5:

Pulversprühbeschichtungsanlage nach einer der vorhergehenden Ausführungsformen,
dadurch gekennzeichnet,
dass das Gehäuse des Rückgewinnungspulver-Vorratsbehälters (48-2) von oben nach unten kegelstumpfförmig enger werdend ausgebildet ist.Powder spray coating system according to one of the preceding embodiments,
characterized,
in that the housing of the recovery powder storage container (48-2) is designed to be narrower from top to bottom in the shape of a truncated cone.

Ausführungsform 6:Embodiment 6:

Pulversprühbeschichtungsanlage nach einer der vorhergehenden Ausführungsformen,
dadurch gekennzeichnet,
dass der Rückgewinnungspulver-Vorratsbehälter (48-2) mit einer Fluidisiervorrichtung (66) versehen ist zur Fluidisierung des im Rückgewinnungspulver-Vorratsbehälter (48-2) vorhandenen Rückgewinnungspulvers mittels Druckluft, welche durch die Fluidisiervorrichtung (66) in den Rückgewinnungspulver-Vorratsbehälter (48-2) einleitbar ist.Powder spray coating system according to one of the preceding embodiments,
characterized,
in that the recovery powder storage container (48-2) is provided with a fluidizing device (66) for fluidizing the recovery powder present in the recovery powder storage container (48-2) by means of compressed air which is passed through the fluidizing device (66) into the recovery powder storage container (48). 2) can be introduced.

Ausführungsform 7:Embodiment 7:

Pulversprühbeschichtungsanlage nach einer der vorhergehenden Ausführungsformen,
dadurch gekennzeichnet,
dass am unteren Ende des Rückgewinnungspulver-Vorratsbehälters (48-2) eine Absperrvorrichtung (64), vorzugsweise in Form von mindestens einem Quetschventil, zum alternativen Absperren oder Öffnen eines Pulverauslasses (204) am unteren Ende des Rückgewinnungspulver-Vorratsbehälters (48-2) vorgesehen ist.Powder spray coating system according to one of the preceding embodiments,
characterized,
a shut-off device (64), preferably in the form of at least one pinch valve, for the alternative shut-off or opening of a powder outlet (204), is provided at the lower end of the recovery powder storage container (48-2). at the lower end of the recovery powder reservoir (48-2) is provided.

Ausführungsform 8:Embodiment 8:

Pulversprühbeschichtungsanlage nach einer der vorhergehenden Ausführungsformen,
dadurch gekennzeichnet,
dass der mindestens eine Zwischenbehälter-Sensor (S1, S2) und/oder der mindestens eine Vorratsbehälter-Sensor (S3, S4), Pulverniveau-Sensoren sind, welche in Abhängigkeit von dem von ihnen detektieren Pulverniveau das genannte Signal erzeugen.Powder spray coating system according to one of the preceding embodiments,
characterized,
in that the at least one intermediate container sensor (S1, S2) and / or the at least one storage container sensor (S3, S4) are powder level sensors which generate said signal as a function of the powder level detected by them.

Ausführungsform 9:Embodiment 9:

Pulversprühbeschichtungsanlage nach einer der vorhergehenden Ausführungsformen,
dadurch gekennzeichnet,
dass die Frischpulver-Versorgungsvorrichtung (70, 74) eine Sensorvorrichtung (76) aufweist, welche in Abhängigkeit von der Menge Frischpulver, welche sich in einem Frischpulverbehälter (12) in der Frischpulver-Versorgungsvorrichtung (70, 74) befindet, ein erstes Signal erzeugt, vorzugsweise mindestens immer dann, wenn die Frischpulvermenge im Frischpulverbehälter (12) unter einen vorbestimmten Restmengenwert abfällt.Powder spray coating system according to one of the preceding embodiments,
characterized,
in that the fresh powder supply device (70, 74) has a sensor device (76) which generates a first signal as a function of the quantity of fresh powder which is present in a fresh powder container (12) in the fresh powder supply device (70, 74), preferably at least whenever the amount of fresh powder in the fresh powder container (12) falls below a predetermined residual amount value.

Ausführungsform 10:Embodiment 10:

Pulversprühbeschichtungsanlage nach Ausführungsform 9,
dadurch gekennzeichnet,
dass die Sensorvorrichtung (76) der Frischpulver-Versorgungsvorrichtung (70, 74) mit dem mindestens einen Steuergerät (3) funktionsmäßig verbunden ist und in dem mindestens einen Steuergerät ein zweites Signal erzeugt, wenn die Frischpulvermenge im Frischpulverbehälter (12) auf einen unteren Grenzmengenwert abgefallen ist, der einen vorbestimmten Abstand unterhalb des Restmengenwertes liegt, bei welchem das genannte erste Signal erzeugt wird.Powder spray coating system according to embodiment 9,
characterized,
in that the sensor device (76) of the fresh powder supply device (70, 74) is functionally connected to the at least one control device (3) and generates a second signal in the at least one control device when the fresh powder quantity in the fresh powder container (12) has dropped to a lower limit value which is a predetermined distance below the residual amount value at which said first signal is generated.

Ausführungsform 11:Embodiment 11:

Pulversprühbeschichtungsanlage nach Ausführungsform 10,
dadurch gekennzeichnet,
dass das mindestens eine Steuergerät (3) bei Erhalt des zweiten Signals der Sensorvorrichtung (76) der Frischpulver-Versorgungsvorrichtung (70, 74) die Pulversprühbeschichtungsanlage auf eine Reservebetriebsphase umschaltet, wenn weiterhin ein Pulverbedarfsignal von dem mindestens einen Zwischenbehälter-Sensor (S1) erzeugt wird, wobei während der Reservebetriebsphase dem Zwischenbehälter (24) nur Rückgewinnungspulver aus dem Pulverreserveabschnitt (202) des Rückgewinnungspulver-Vorratsbehälters (48-2) zugeführt wird, jedoch kein Frischpulver von der Frischpulver-Versorgungsvorrichtung (70, 74).Powder spray coating system according to embodiment 10,
characterized,
the at least one control device (3), upon receiving the second signal of the sensor device (76) of the fresh powder supply device (70, 74), switches the powder spray coating system to a reserve operating phase if a powder demand signal is also generated by the at least one intermediate container sensor (S1) wherein during the reserve operation phase, only recovery powder from the powder reserve section (202) of the recovery powder storage tank (48-2) is supplied to the intermediate tank (24), but no fresh powder from the fresh powder supply device (70, 74).

Ausführungsform 12:Embodiment 12:

Pulversprühbeschichtungsanlage nach Ausführungsform 9,
dadurch gekennzeichnet,
dass die Sensorvorrichtung (76) der Frischpulver-Versorgungsvorrichtung (70, 74) mit dem mindestens einen Steuergerät (3) funktionsmäßig verbunden ist, und dass das mindestens eine Steuergerät (3) derart ausgebildet ist, dass es in Erwiderung auf das erste Signal von der Sensorvorrichtung (76) der Frischpulver-Versorgungsvorrichtung (70, 74) die Sprühbeschichtungsanlage auf eine Reservebetriebsphase umschaltet, wenn weiterhin ein Pulverbedarfsignal von dem mindestens einen Zwischenbehälter-Sensor (S1) erzeugt wird, wobei in der Reservebetriebsphase dem Zwischenbehälter (24) nur Rückgewinnungspulver aus dem Pulverreserveabschnitt (202) des Rückgewinnungspulver-Vorratsbehälters (48-2) zugeführt wird, jedoch kein Frischpulver von der Frischpulver-Versorgungsvorrichtung (70, 74).Powder spray coating system according to embodiment 9,
characterized,
in that the sensor device (76) of the fresh powder supply device (70, 74) is operatively connected to the at least one control device (3), and that the at least one control device (3) is designed such that it responds to the first signal from the Sensor device (76) of the fresh powder supply device (70, 74), the spray coating system switches to a reserve operating phase, when further a powder demand signal from the at least one surge tank sensor (S1) is generated, wherein in the reserve operating phase the intermediate container (24) only recovery powder from the Powder reserve portion (202) of the recovery powder storage container (48-2) is supplied, but no fresh powder from the fresh powder supply device (70, 74).

Ausführungsform 13:Embodiment 13:

Pulversprühbeschichtungsanlage nach Ausführungsform 9,
dadurch gekennzeichnet,
dass die Sensorvorrichtung (76) der Frischpulver-Versorgungsvorrichtung (70, 74) mit dem mindestens einen Steuergerät (3) funktionsmäßig verbunden ist, und dass das mindestens eine Steuergerät (3) derart ausgebildet ist, dass es in Erwiderung auf das erste Signal von der Sensorvorrichtung (76) der Frischpulver-Versorgungsvorrichtung (70, 74) die Sprühbeschichtungsanlage auf eine Reservebetriebsphase umschaltet, wenn weiterhin ein Pulverbedarfsignal von dem mindestens einen Zwischenbehälter-Sensor (S1) erzeugt wird, wobei in der Reservebetriebsphase dem Zwischenbehälter (24) nur Rückgewinnungspulver aus dem Pulverreserveabschnitt (202) des Rückgewinnungspulver-Vorratsbehälters (48-2) zugeführt wird, jedoch kein Frischpulver von der Frischpulver-Versorgungsvorrichtung (70, 74), und wobei das Steuergerät (3) eine Zeitverzögerungsschaltung enthält, durch welche die Umschaltung auf die Reservebetriebsphase erst nach Ablauf einer vorbestimmten Zeitverzögerungsdauer nach Erhalt des ersten Signals der Sensorvorrichtung (76) der Frischpulver-Versorgungsvorrichtung (70, 74) bewirkt wird.Powder spray coating system according to embodiment 9,
characterized,
in that the sensor device (76) of the fresh powder supply device (70, 74) is functionally connected to the at least one control device (3), and that the at least one control device (3) is designed such that it responds on the first signal from the sensor device (76) of the fresh powder supply device (70, 74), the spray coating system switches to a reserve operating phase, when a powder demand signal from the at least one surge tank sensor (S1) is further generated, wherein in the reserve operating phase the intermediate tank ( 24) only recovery powder from the powder reserve section (202) of the recovery powder storage container (48-2) is supplied, but no fresh powder from the fresh powder supply device (70, 74), and wherein the control device (3) includes a time delay circuit, by which Switching to the reserve operating phase only after a predetermined time delay period after receipt of the first signal of the sensor device (76) of the fresh powder supply device (70, 74) is effected.

Ausführungsform 14:Embodiment 14:

Pulversprühbeschichtungsanlage nach einer der Ausführungsformen 9 bis 13,
dadurch gekennzeichnet,
dass die Sensorvorrichtung (76) der Frischpulver-Versorgungsvorrichtung (70, 72) eine Wägevorrichtung zum Wägen des Gewichts des Frischpulvers in einem Frischpulverbehälter (12) ist.Powder spray coating system according to any one of embodiments 9 to 13,
characterized,
in that the sensor device (76) of the fresh powder supply device (70, 72) is a weighing device for weighing the weight of the fresh powder in a fresh powder container (12).

Ausführungsform 15:Embodiment 15:

Pulversprühbeschichtungsanlage nach einer der vorhergehenden Ausführungsformen,
dadurch gekennzeichnet,
dass auf dem Pulverweg des Rückgewinnungspulvers von dem Rückgewinnungspulver-Vorratsbehälter (48-2) zu dem Zwischenbehälter (24) eine Siebvorrichtung (10) angeordnet ist.Powder spray coating system according to one of the preceding embodiments,
characterized,
in that a screening device (10) is arranged on the powder path of the recovery powder from the recovery powder storage container (48-2) to the intermediate container (24).

Ausführungsform 16:Embodiment 16:

Pulversprühbeschichtungsanlage nach Ausführungsform 15,
dadurch gekennzeichnet,
dass auch der Frischpulverzufuhrweg von der Frischpulver-Versorgungsvorrichtung (70, 74) zum Zwischenbehälter (24) durch die Siebvorrichtung (10) verläuft, sodass auch das Frischpulver gesiebt wird.Powder spray coating system according to embodiment 15,
characterized,
that the Frischpulverzufuhrweg from the fresh powder supply device (70, 74) to the intermediate container (24) through the sieve device (10), so that the fresh powder is sieved.

Ausführungsform 17:Embodiment 17:

Pulversprühbeschichtungsanlage nach Ausführungsform 15 oder 16,
gekennzeichnet durch
eine Pulverpumpe (4) in einem, vorzugsweise zur Außenatmosphäre geschlossenen, Pulverwegabschnitt (50) des Rückgewinnungspulvers von dem Rückgewinnungspulver-Vorratsbehälter (48-2) zur Eingangsseite der Siebvorrichtung (10), wobei vorzugsweise auch die Eingangsseite der Siebvorrichtung gegenüber der Außenatmosphäre für Beschichtungspulver geschlossen ist.Powder spray coating system according to embodiment 15 or 16,
marked by
a powder pump (4) in a preferably closed to the outside, Pulverwegabschnitt (50) of the recovery powder from the recovery powder reservoir (48-2) to the input side of the screening device (10), preferably also the input side of the screening device against the outside atmosphere for coating powder closed is.

Ausführungsform 18:Embodiment 18:

Pulversprühbeschichtungsanlage nach Ausführungsform 16 oder 17,
gekennzeichnet durch
jeweils eine Pulverpumpe (4) in dem mindestens einen, vorzugsweise zur Außenatmosphäre geschlossenen, Pulverwegabschnitt (16) des Frischpulvers von dem Frischpulverbehälter (12) der Frischpulver-Versorgungsvorrichtung (70, 74) zu der Eingangsseite der Siebvorrichtung (10), wobei vorzugsweise auch die Eingangsseite der Siebvorrichtung bezüglich des Beschichtungspulvers gegenüber der Außenatmosphäre geschlossen ist.Powder spray coating system according to embodiment 16 or 17,
marked by
a powder pump (4) in the at least one, preferably closed to the outside atmosphere, Pulverwegabschnitt (16) of the fresh powder from the fresh powder container (12) of the fresh powder supply device (70, 74) to the input side of the screening device (10), preferably also the Input side of the screening device with respect to the coating powder against the outside atmosphere is closed.

Ausführungsform 19:Embodiment 19:

Pulversprühbeschichtungsanlage nach einer der Ausführungsformen 15 bis 18,
gekennzeichnet durch
jeweils eine Pulverpumpe (4) in dem mindestens einen, vorzugsweise zur Außenatmosphäre geschlossenen, Pulverwegabschnitt (20) von einer Ausgangsseite der Siebvorrichtung (10) in den Zwischenbehälter (24), wobei vorzugsweise auch die Ausgangsseite der Siebvorrichtung (10) und der Zwischenbehälter (24) bezüglich des Beschichtungspulvers zur Außenatmosphäre geschlossen sind.Powder spray coating system according to any one of embodiments 15 to 18,
marked by
in each case a powder pump (4) in the at least one, preferably closed to the outside atmosphere, Pulverwegabschnitt (20) from an output side of the screening device (10) in the intermediate container (24), preferably also the output side of the screening device (10) and the intermediate container (24 ) are closed to the outside atmosphere with respect to the coating powder.

Ausführungsform 20:Embodiment 20:

Pulversprühbeschichtungsanlage nach mindestens einer der vorhergehenden Ausführungsformen,
gekennzeichnet durch
jeweils eine Pulverpumpe (4) in dem mindestens einen Pulverweg (38) des Beschichtungspulvers von dem Zwischenbehälter (24) zu der mindestens einen Sprühvorrichtung (40).Powder spray coating system according to at least one of the preceding embodiments,
marked by
in each case a powder pump (4) in the at least one powder path (38) of the coating powder from the intermediate container (24) to the at least one spray device (40).

Ausführungsformen 21:Embodiments 21:

Pulversprühbeschichtungsverfahren, insbesondere zum Betrieb der Pulversprühbeschichtungsanlage nach einer der vorhergehenden Ausführungsformen, bei welchem aus einem Zwischenbehälter (24) Beschichtungspulver zu mindestens einer Sprühvorrichtung (40) pneumatisch gefördert wird; mittels mindestens eines Sensors (S1) am Zwischenbehälter (24) ein Pulverbedarfsignal erzeugt wird, wenn das Pulverniveau im Zwischenbehälter (24) ein vorbestimmtes Pulvermindestniveau unterschreitet; mittels eines Zyklonabscheiders (48) Rückgewinnungspulver aus einem Luftstrom abgeschieden wird, welches versprühtes Überschusspulver enthält, welches ein zu beschichtendes Objekt verfehlte; wobei
Rückgewinnungspulver auf dem Weg vom Zyklonabscheider (48) zu dem Zwischenbehälter (24) in einem Rückgewinnungspulver-Vorratsbehälter (48-2) zwischengespeichert wird, dass mittels mindestens einem Vorratsbehälter-Sensor (S3) ein Rückgewinnungspulver-Informationssignal in Abhängigkeit davon erzeugt wird, ob das Pulverniveau im Rückgewinnungspulver-Vorratsbehälter (48-2) unter einem Mindestniveau oder mindestens auf dem Mindestniveau ist; dass unversprühtes Frischpulver aus einem Frischpulverbehälter (12) dem Zwischenbehälter (24) auf einem Pulverweg zugeführt wird, welcher den Zyklonabscheider (48) und den Rückgewinnungspulver-Vorratsbehälter (48-2) umgeht; dass in Abhängigkeit von Signalen von den Sensoren (S1, S3) mittels mindestens eines Steuergerätes (3) die Pulversprühbeschichtungsanlage automatisch gemäß einer ersten Betriebsphase gesteuert wird, bei welcher dem Zwischenbehälter (24) nur Rückgewinnungspulver aus dem Rückgewinnungspulver-Vorratsbehälter (48-2) zugeführt wird, jedoch kein Frischpulver von der Frischpulver-Versorgungsvorrichtung (70, 74), wenn vom Zwischenbehälter-Sensor (S1) ein Pulverbedarfsignal und gleichzeitig vom Rückgewinnungspulver-Vorratsbehälter-Sensor (S3) ein Rückgewinnungspulver-Informationssignal vorliegt, welch letzteres einem auf oder über dem vorbestimmten Mindestniveau liegenden Rückgewinnungspulverniveau entspricht, jedoch automatisch auf eine zweite Betriebsphase umgeschaltet wird und gemäß der zweiten Betriebsphase die Pulversprühbeschichtungsanlage betrieben wird, bei welcher dem Zwischenbehälter (24) nur Frischpulver von der Frischpulver-Versorgungsvorrichtung (70, 74) zugeführt wird, jedoch kein Rückgewinnungspulver aus dem Rückgewinnungspulver-Vorratsbehälter (48-2), wenn vom Zwischenbehälter-Sensor (S1) ein Pulverbedarfsignal und gleichzeitig vom Rückgewinnungspulver-Vorratsbehälter-Sensor (S3) ein Rückgewinnungspulver-Informationssignal vorliegt, welch letzteres einem unter dem Mindestniveau liegenden Rückgewinnungspulverniveau entspricht,
dadurch gekennzeichnet,
dass in einem unteren Pulverreserveabschnitt (202) des Rückgewinnungspulver-Vorratsbehälters (48-2) während der ersten Betriebsphase eine Rückgewinnungspulver-Reservemenge gespeichert wird, und dass automatisch von der zweiten Betriebsphase auf eine Reservebetriebsphase umgeschaltet wird, bei welcher dem Zwischenbehälter (24) nur Rückgewinnungspulver aus Rückgewinnungspulver-Reservemenge des Pulverreserveabschnitts (202) zugeführt wird, jedoch kein Frischpulver von der Frischpulver-Versorgungsvorrichtung (70, 74), wenn nach einer vorbestimmten Verzögerungszeit nach dem Umschalten von der ersten Betriebsphase auf die zweite Betriebsphase weiterhin vom Zwischenbehälter-Sensor (S1) ein Pulverbedarfssignal vorliegt.Powder spray coating method, in particular for operating the powder spray coating system according to one of the preceding embodiments, in which coating powder is pneumatically conveyed from an intermediate container (24) to at least one spray device (40); by means of at least one sensor (S1) on the intermediate container (24) a powder demand signal is generated when the powder level in the intermediate container (24) falls below a predetermined minimum powder level; using a cyclone separator (48), reclaiming recovery powder from an air stream containing sprayed excess powder which missed an object to be coated; in which
Recovery powder is intermediately stored on the way from the cyclone separator (48) to the intermediate container (24) in a recovery powder reservoir (48-2), that by means of at least one reservoir sensor (S3), a recovery powder information signal is generated in dependence Powder level in Recovery Powder Reservoir (48-2) is below a minimum level or at least at the minimum level; that un-sprayed fresh powder from a fresh powder container (12) is supplied to the intermediate container (24) on a powder path which bypasses the cyclone separator (48) and the recovery powder storage container (48-2); in that in dependence on signals from the sensors (S1, S3) by means of at least one control unit (3), the powder spray coating system is automatically controlled according to a first operating phase in which only recovery powder from the recovery powder storage container (48-2) is supplied to the intermediate container (24) is, but no fresh powder from the A fresh powder supply device (70, 74) when there is a powder demand signal from the surge tank sensor (S1) and a recovery powder information signal simultaneously from the recovery powder reservoir sensor (S3), the latter corresponding to a recovery powder level at or above the predetermined minimum level is automatically switched to a second phase of operation and according to the second phase of operation, the powder spray coating plant is operated in which the intermediate container (24) only fresh powder from the fresh powder supply device (70, 74) is supplied, but no recovery powder from the recovery powder reservoir (48-74) 2) when there is a powder demand signal from the tundish sensor (S1) and, at the same time, a recovery powder information signal from the recovery powder hopper sensor (S3), the latter being a recovery powder level e below the minimum level orresponds,
characterized,
in a lower powder reserve section (202) of the recovery powder reservoir (48-2) during the first phase of operation, a recovery powder reserve amount is stored, and that is automatically switched from the second phase of operation to a reserve operating phase, in which the intermediate container (24) only recovery powder is supplied from the recovery powder reserve amount of the powder reserve portion (202), but no fresh powder from the fresh powder supply device (70, 74), if after a predetermined delay time after switching from the first phase of operation to the second phase of operation further from the tundish sensor (S1) a powder requirement signal is present.

Claims (21)

  1. A powder spray coating system comprising an intermediate receptacle (24) from which coating powder can be pneumatically conveyed to at least one spraying mechanism (40); at least one sensor (S1) at the intermediate receptacle (24) to generate a powder demand signal when the powder level in the intermediate receptacle (24) falls below a predetermined minimum powder level; a powder separator (48) to separate recovered powder from an airflow containing sprayed excess powder which failed to reach an object being coated; wherein a recovered powder reservoir (48-2) is arranged in the path of the recovered powder from the powder separator (48) to the intermediate receptacle (24) so that the recovered powder can be temporarily stored in said recovered powder reservoir (48-2) before being fed to the intermediate receptacle (24); wherein the recovered powder reservoir (48-2) is provided with at least one reservoir sensor (S3) for generating a recovered powder data signal based on whether the powder level is below a minimum level or at least at the minimum level; wherein a fresh powder feed device (70, 74) is provided to feed unsprayed fresh powder from a fresh powder container (12; 14) into the intermediate receptacle (24) along at least one powder path which bypasses both the powder separator (48) as well as the recovered powder reservoir (48-2); wherein at least one control device (3) operationally connected to the sensors (S1, S3) is provided and designed so as to automatically control the powder spray coating system such that in a first operating phase only recovered powder from the recovered powder reservoir (48-2), but no fresh powder from the fresh powder feed device (70, 74), is fed into the intermediate receptacle (24) when there is a powder demand signal from the intermediate receptacle sensor (S1 ) simultaneously with a recovered powder data signal from the recovered powder reservoir sensor (S3), the latter signal corresponding to a recovered powder level at or above the predetermined minimum level, whereas in a second operating phase, only fresh powder from the fresh powder feed device (70, 74), but no recovered powder from the recovered powder reservoir (48-2), is supplied to the intermediate receptacle (24) upon a powder demand signal from the intermediate receptacle sensor (S1) simultaneously with a recovered powder data signal from the reservoir sensor (S3), the latter signal corresponding to a recovered powder level below the minimum level, wherein
    the at least one reservoir sensor (S3) is arranged at such a height on the recovered powder reservoir (48-2) that said recovered powder reservoir (48-2) has a powder reserve section (202) situated below the reservoir sensor (S3) able to store a predetermined reserve quantity of recovered powder up to the minimum level, characterized in that
    the powder separator (48) is a cyclone separator and that the at least one control device (3) is designed to automatically switch the powder spray coating system from the second operating phase into a reserve operating phase in which only recovered powder from the powder reserve section (202) of the recovered powder reservoir (48-2), but no fresh powder from the fresh powder feed device (70, 74), is fed to the intermediate receptacle (24) when there continues to be a powder demand signal from the intermediate receptacle sensor (S1) after a predetermined time delay following the switch from the first operating phase to the second operating phase, wherein the at least one control device (3) has a time delay circuit defining the time delay or at which the time delay can be variably adjusted.
  2. The powder spray coating system according to claim 1,
    characterized in that
    the recovered powder reservoir (48-2) is provided with a second reservoir sensor (S4) for generating an emergency signal each time the recovered powder level in the recovered powder reservoir (48-2) drops to a predetermined distance below a predetermined lower limit level for the predetermined recovered powder minimum level of the first reservoir sensor (S3).
  3. The powder spray coating system according to one of the preceding claims, characterized in that
    the recovered powder reservoir (48-2) is arranged underneath the cyclone separator (48) and a vertical passage is formed between the two through which recovered powder can drop from the cyclone separator (48) into the recovered powder reservoir (48-2) by gravity.
  4. The powder spray coating system according to any one of the preceding claims, characterized in that
    the recovered powder reservoir (48-2) has a container housing which is a lower extension of the cyclone separator (48) housing.
  5. The powder spray coating system according to any one of the preceding claims, characterized in that
    the housing of the recovered powder reservoir (48-2) tapers frustoconically from top to bottom.
  6. The powder spray coating system according to any one of the preceding claims, characterized in that
    the recovered powder reservoir (48-2) is provided with a fluidizing means (66) for fluidizing recovered powder present in the recovered powder reservoir (48-2) by means of compressed air which can be introduced into the recovered powder reservoir (48-2) via the fluidizing means (66).
  7. The powder spray coating system according to any one of the preceding claims, characterized in that
    a cut-off mechanism (64), preferably in the form of at least one pinch valve, is provided at the lower end of the recovered powder reservoir (48-2) to alternatingly close off or open a powder outlet (204) provided at the lower end of the recovered powder reservoir (48-2).
  8. The powder spray coating system according to any one of the preceding claims, characterized in that
    the at least one intermediate receptacle sensor (S1, S2) and/or the at least one reservoir sensor (S3, S4) are powder level sensors which generate the cited signals as a function of the powder levels they detect.
  9. The powder spray coating system according to any one of the preceding claims, characterized in that
    the fresh powder feed device (70, 74) comprises a sensor device (76) which generates a first signal as a function of the quantity of fresh powder in a fresh powder container (12) within the fresh powder feed device (70, 74), preferably at least always when the quantity of fresh powder in the fresh powder container (12) falls below a predetermined residual quantity.
  10. The powder spray coating system according to claim 9,
    characterized in that
    the sensor device (76) of the fresh powder feed device (70, 74) is operationally connected to the at least one control device (3) and generates a second signal in the at least one control device when the quantity of fresh powder in the fresh powder container (12) falls to a lower quantity limit value at a predetermined distance below the residual quantity at which said first signal is generated.
  11. The powder spray coating system according to claim 10,
    characterized in that
    upon receiving the second signal from the sensor device (76) of the fresh powder feed device (70, 74), the at least one control device (3) switches the powder spray coating system to a reserve operating phase when the at least one intermediate receptacle sensor (S1) continues to generate a powder demand signal, wherein the intermediate receptacle (24) is only fed recovered powder from the powder reserve section (202) of the recovered powder reservoir (48-2), but no fresh powder from the fresh powder feed device (70, 74), during the reserve operating phase.
  12. The powder spray coating system according to claim 9,
    characterized in that
    the sensor device (76) of the fresh powder feed device (70, 74) is operationally connected to the at least one control (3) and that the at least one control device (3) is designed such that it switches the spray coating system to a reserve operating phase in response to the first signal from the sensor device (76) of the fresh powder feed device (70, 74) when the at least one intermediate receptacle sensor (S1) continues to generate a powder demand signal, wherein the intermediate receptacle (24) is only fed recovered powder from the powder reserve section (202) of the recovered powder reservoir (48-2), but no fresh powder from the fresh powder feed device (70, 74), during the reserve operating phase.
  13. The powder spray coating system according to claim 9,
    characterized in that
    the sensor device (76) of the fresh powder feed device (70, 74) is operationally connected to the at least one control device (3) and that the at least one control device (3) is designed so as to switch the spray coating system to a reserve operating phase in response to the first signal from the sensor device (76) of the fresh powder feed device (70, 74) when the at least one intermediate receptacle sensor (S1) continues to generate a powder demand signal, wherein the intermediate receptacle (24) is only fed recovered powder from the powder reserve section (202) of the recovered powder reservoir (48-2), but no fresh powder from the fresh powder feed device (70, 74), during the reserve operating phase, and wherein the control device (3) comprises a time delay switch which does not effect the switching to the reserve operating phase until after a predetermined time delay has elapsed after having received the first signal of the sensor device (76) of the fresh powder feed device (70, 74).
  14. The powder spray coating system according to any one of claims 9 to 13, characterized in that
    the sensor device (76) of the fresh powder feed device (70, 74) is a scale for weighing the weight of the fresh powder in a fresh powder container (12).
  15. The powder spray coating system according to any one of the preceding claims, characterized in that
    a sieve device (10) is arranged in the path of the recovered powder from the recovered powder reservoir (48-2) to the intermediate receptacle (24).
  16. The powder spray coating system according to claim 15,
    characterized in that
    the path of the fresh powder feed from the fresh powder feed device (70, 74) to the intermediate receptacle (24) also passes through the sieve device (10) such that the fresh powder is also sifted.
  17. The powder spray coating system according to claim 15 or 16,
    characterized by
    a powder pump (4) in a powder path section (50) of the recovered powder from the recovered powder reservoir (48-2) to the inlet side of the sieve device (10), which is preferably sealed to the external atmosphere, wherein the sieve inlet side is preferably also coating powder-tight relative to the external atmosphere.
  18. The powder spray coating system according to claim 16 or 17,
    characterized by
    one powder pump (4) each in the at least one powder path section (16) of the fresh powder, which is preferably sealed to the external atmosphere, from the fresh powder container (12) of the fresh powder feed device (70, 74) to the inlet side of the sieve device (10), wherein the sieve inlet side is preferably also sealed to the external atmosphere as regards the coating powder.
  19. The powder spray coating system according to any one of claims 15 to 18, characterized by
    one powder pump (4) each in the at least one powder path section (20), which is preferably sealed relative to the external atmosphere, from an outlet side of the sieve device (10) into the intermediate receptacle (24), wherein the outlet side of the sieve device (10) and the intermediate receptacle (24) are preferably also sealed to the external atmosphere as regards the coating powder.
  20. The powder spray coating system according to at least one of the preceding claims, characterized by
    one powder pump (4) each in the at least one coating powder path (38) from the intermediate receptacle (24) to the at least one spraying mechanism (40).
  21. A powder spray coating method, particularly for operating the powder spray coating system according to any one of the preceding claims, in which coating powder is pneumatically conveyed from an intermediate receptacle (24) to at least one spraying mechanism (40); a powder demand signal is generated by means of at least one sensor (S1) at the intermediate receptacle (24) when the powder level in the intermediate receptacle (24) falls short of a predetermined minimum powder level; recovered powder is separated out of an airflow containing sprayed excess powder which failed to reach an object to be coated by means of a powder separator (48);
    wherein recovered powder is temporarily stored in a recovered powder reservoir (48-2) along the path from the powder separator (48) to the intermediate receptacle (24), wherein a recovered powder data signal is generated by means of at least one reservoir sensor (S3) as a function of whether the powder level in the recovered powder reservoir (48-2) is below a minimum level or at least at the minimum level; wherein unsprayed fresh powder is supplied to the intermediate receptacle (24) from a fresh powder container (12) on one powder path which bypasses the powder separator (48) and the recovered powder reservoir (48-2); wherein based on the signals from the sensors (S1, S3), at least one control device (3) automatically controls the powder spray coating system in a first operating phase in which the intermediate receptacle (24) is only fed recovered powder from the recovered powder reservoir (48-2), but no fresh powder from the fresh powder feed device (70, 74), when there is simultaneously a powder demand signal from the intermediate receptacle sensor (S1) and a recovered powder data signal from the recovered powder reservoir sensor (S3) which corresponds to a recovered powder level at or above the predetermined minimum level, but the powder spray coating system automatically switches into and is operated in a second operating phase in which the intermediate receptacle (24) is only fed fresh powder from the fresh powder feed device (70, 74), but no recovered powder from the recovered powder reservoir (48-2), when there is simultaneously a powder demand signal from the intermediate receptacle sensor (S1) and a recovered powder data signal from the recovered powder reservoir sensor (S3) corresponding to a recovered powder level below the minimum level,
    characterized in that
    the powder separator (48) is a cyclone separator and that a reserve quantity of recovered powder is stored in a lower powder reserve section (202) of the recovered powder reservoir (48-2) during the first operating phase and that switching from the second operating phase into a reserve operating phase in which the intermediate receptacle (24) is only supplied with recovered powder from the reserve quantity of recovered powder of the powder reserve section (202), but no fresh powder from the fresh powder feed device (70, 74), ensues automatically when there continues to be a powder demand signal from the intermediate receptacle sensor (S1) after a predetermined delay time following the switch from the first operating phase to the second operating phase.
EP07120752.6A 2007-02-02 2007-11-15 Powder spray coating facility and powder spray coating method Active EP1952892B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE102007005309A DE102007005309A1 (en) 2007-02-02 2007-02-02 Powder spray coating machine and powder spray coating method

Publications (2)

Publication Number Publication Date
EP1952892A1 EP1952892A1 (en) 2008-08-06
EP1952892B1 true EP1952892B1 (en) 2014-03-26

Family

ID=39352641

Family Applications (1)

Application Number Title Priority Date Filing Date
EP07120752.6A Active EP1952892B1 (en) 2007-02-02 2007-11-15 Powder spray coating facility and powder spray coating method

Country Status (4)

Country Link
US (1) US7971551B2 (en)
EP (1) EP1952892B1 (en)
DE (1) DE102007005309A1 (en)
WO (1) WO2008093180A1 (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102010025740A1 (en) * 2010-06-30 2012-01-05 Illinois Tool Works Inc. Powder supply device and method for automatically cleaning a powder supply device
DE102010025749B4 (en) * 2010-06-30 2014-11-20 Gema Switzerland Gmbh Powder supply device for a powder coating system
DE102010039473B4 (en) * 2010-08-18 2014-11-20 Gema Switzerland Gmbh Powder supply device for a powder coating system
DE102011004035A1 (en) * 2011-02-14 2012-08-16 Illinois Tool Works Inc. Powder pump for conveying coating powder
US9162245B1 (en) 2012-03-29 2015-10-20 BTD Wood Powder Coating, Inc. Powder coating conveyor support
US8721396B1 (en) 2013-03-12 2014-05-13 BTD Wood Powder Coating, Inc. Method for preparing and buffing a powder coated wood substrate
US9358580B1 (en) 2013-03-12 2016-06-07 BTD Wood Powder Coating, Inc. Method for preparing and top coating a powder coated wood substrate
DE102013211550A1 (en) * 2013-06-19 2014-12-24 Gema Switzerland Gmbh Powder conveying device, in particular for coating powder
US11829123B2 (en) * 2021-12-28 2023-11-28 FTD Solutions Inc. Systems and methods for managing material balance between incoming and outgoing streams of a material in an industrial system

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH529590A (en) * 1971-07-20 1972-10-31 Gema Ag App Bau Electrostatic coating plant - with powdered coating material feed system including recycling of waste
US3960323A (en) 1971-11-02 1976-06-01 Nordson Corporation Powder spray system
CH593717A5 (en) 1974-11-14 1977-12-15 Gema Ag
DE3929678A1 (en) 1989-09-07 1991-03-28 Porsche Ag GEARING DEVICE FOR A GEAR CHANGER OF A MOTOR VEHICLE
DE3926624A1 (en) 1989-08-11 1991-02-14 Gema Ransburg Ag ELECTROSTATIC POWDER COATING DEVICE
US5474609A (en) * 1992-06-30 1995-12-12 Nordson Corporation Methods and apparatus for applying powder to workpieces
US5454256A (en) * 1992-08-13 1995-10-03 Nordson Corporation Powder coating system with dew-point detection
DE4239496A1 (en) 1992-11-25 1994-05-26 Gema Volstatic Ag St Gallen Electrostatic powder spray coating appts. - uses powder delivery container as powder supply and recovers excess sprayed powder
DE4300832A1 (en) * 1993-01-14 1994-07-21 Gema Volstatic Ag St Gallen Powder spray coater
CA2200343C (en) * 1994-10-11 2004-04-13 Jeffrey R. Shutic Vehicle powder coating system
DE19517229A1 (en) * 1995-05-11 1996-11-14 Gema Volstatic Ag Powder spray coating by suction through self-supporting cover
SE9503448D0 (en) * 1995-10-05 1995-10-05 Herberts Powder Coatings Ab Powder handling systems in powder coating plants
DE19808765A1 (en) * 1998-03-02 1999-09-16 Wagner Int Powder coating system and method for feeding and mixing powder in a coating system
DE19959473A1 (en) 1999-12-10 2001-06-13 Frederic Dietrich Device and method for the pneumatic conveying of powdery substances and use of the device
US20020014200A1 (en) * 2000-04-25 2002-02-07 Stemler Terry L. Granule coating apparatus and method
DE10145448A1 (en) 2001-09-14 2003-05-22 Bayerische Motoren Werke Ag Device for conveying powder and method for operating it
ITMI20031419A1 (en) 2003-07-11 2005-01-12 Studio A Z Di Giancarlo Simontacchi DEVICE FOR THE TRANSPORT OF POWDERS THROUGH PIPES
DE10353968A1 (en) 2003-11-19 2005-07-07 Itw Gema Ag Coating powder conveying device, especially for transporting powder from a storage container, e.g. a sack or bag, has a hose membrane pump for transporting powder that has been fluidized using compressed air
US20050158187A1 (en) 2003-11-24 2005-07-21 Nordson Corporation Dense phase pump for dry particulate material
JP4730780B2 (en) * 2006-04-18 2011-07-20 株式会社リコー Powder supply apparatus and image forming apparatus

Also Published As

Publication number Publication date
WO2008093180A1 (en) 2008-08-07
US7971551B2 (en) 2011-07-05
EP1952892A1 (en) 2008-08-06
US20080187658A1 (en) 2008-08-07
DE102007005309A1 (en) 2008-08-07

Similar Documents

Publication Publication Date Title
EP1952892B1 (en) Powder spray coating facility and powder spray coating method
EP1953098B1 (en) Emptying device for powder sacks for powder spray coating facilities
DE102010039473B4 (en) Powder supply device for a powder coating system
DE102010025749B4 (en) Powder supply device for a powder coating system
DE102007005312A1 (en) Powder recovery device for a powder spray coating machine
DE102011004352B4 (en) Device for the pneumatic conveying of powder
EP2864056B1 (en) Device for conveying coating powder from a powder container
DE19611533B4 (en) Device for powder coating
DE102007005306B4 (en) Powder feed device from a powder spray coating machine
EP1953507A1 (en) Powder level sensor unit for spray coating powder
DE102007005310A1 (en) Coating powder filter device
DE102010025740A1 (en) Powder supply device and method for automatically cleaning a powder supply device
EP3238832B2 (en) Powder conveying device for conveying coating powder to a powder applicator, powder coating installation and method for operating the powder conveying device
EP0606577B1 (en) Powder spray coating device
EP1427657B1 (en) Device and method for transferring a dusty, powdery, grain-like or granular conveyed material out of a storage receptacle and into a working or transfer receptacle or a similar accommodating space
EP3218117B1 (en) Powder container for a powder coating installation
EP3043923B1 (en) Powder supply by means of a dense flux pump for a coating system
EP3277435B1 (en) Distribution system for powder air mixture
DE19613967A1 (en) Spraying method for object coating
DE102011004595A1 (en) Sieve insert for a powder container of a powder supply device
DE102008056369A1 (en) Cyclone separator and powder recovery device for a powder coating plant with a cyclone separator
EP1342505B1 (en) Assembly for the powder coating of objects
WO2018072909A1 (en) Cyclone separator
DE102006041527A1 (en) Powder feed pump and associated operating method
EP4141390A1 (en) Measuring device for measuring a coating powder mass flow, which can be generated with compressed gas, in a powder line and conveying device for coating powder

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20071117

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA HR MK RS

17Q First examination report despatched

Effective date: 20081016

AKX Designation fees paid

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: GEMA SWITZERLAND GMBH

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

INTG Intention to grant announced

Effective date: 20131018

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

Ref country code: CH

Ref legal event code: NV

Representative=s name: FIAMMENGHI-FIAMMENGHI, CH

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 658664

Country of ref document: AT

Kind code of ref document: T

Effective date: 20140415

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: GERMAN

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 502007012904

Country of ref document: DE

Effective date: 20140508

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

REG Reference to a national code

Ref country code: NL

Ref legal event code: VDEP

Effective date: 20140326

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140626

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140726

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140728

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 502007012904

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20150106

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 502007012904

Country of ref document: DE

Effective date: 20150106

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20141130

Ref country code: LU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20141115

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20141115

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20150731

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20141115

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20141115

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20141201

REG Reference to a national code

Ref country code: AT

Ref legal event code: MM01

Ref document number: 658664

Country of ref document: AT

Kind code of ref document: T

Effective date: 20141115

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20141115

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140627

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20071115

Ref country code: MT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20140326

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230621

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20231129

Year of fee payment: 17

Ref country code: CH

Payment date: 20231201

Year of fee payment: 17