Claims
- 1. Apparatus for supplying powder coating material to coating dispensers for deposition onto objects transmitted through a powder spray booth, comprising:
a primary hopper containing powder coating material; a feed hopper; a first transfer device, connected between said primary hopper and said feed hopper, which transmits powder coating material under the application of negative pressure from said primary hopper to said feed hopper; and a second transfer device which transmits powder coating material from said feed hopper to dispensing devices associated with the powder spray booth.
- 2. The apparatus of claim 1 in which said primary hopper is located at a remote position relative to said feed hopper.
- 3. The apparatus of claim 1 in which said feed hopper is separated a substantial distance from said primary hopper and is adapted to be located in a position close to the powder spray booth compared to said primary hopper.
- 4. The apparatus of claim 1 in which said second transfer device is a powder pump connected to said feed hopper, said powder pump being effective to transfer by positive pressure the powder coating material within said feed hopper to dispensing devices associated with the powder spray booth.
- 5. The apparatus of claim 1 further including a third transfer device, connected to said primary hopper, which transmits coating material under the application of negative pressure from a source of powder coating material to said primary hopper.
- 6. The apparatus of claim 5 in which said third transfer device comprises:
a powder receiver unit including a powder collection chamber connected to the source of powder coating material; a first device which transfers powder coating material from the source into said powder collection chamber under the influence of negative pressure; a second device which transfers a metered quantity of powder coating material from said powder collection chamber into said primary hopper.
- 7. The apparatus of claim 6 in which said second transfer device comprises:
a powder receiver unit including a powder collection chamber connected to said primary hopper; a first device which transfers powder coating material from said primary hopper into said powder collection chamber under the influence of negative pressure; a second device which transfers a metered quantity of powder coating material from said powder collection chamber into said feed hopper.
- 8. The apparatus of claim 7 in which said powder receiver unit of each of said second and third transfer devices includes a clean air chamber separated from said powder collection chambers thereof, at least one cartridge filter being located within said powder collection chambers and in communication with said clean air chambers, and means for dislodging powder coating material collected on said cartridge filter.
- 9. The apparatus of claim 7 in which said first device comprises a vacuum pump.
- 10. The apparatus of claim 7 in which said second device of each of said second and third transfer devices comprises:
a metering air lock connected to said powder collection chamber; and a sieve connected between said metering air lock and said primary hopper or said feed hopper.
- 11. The apparatus of claim 1 further including:
a transfer line interconnecting said primary hopper and said feed hopper; a first valve, mounted in said transfer line, for turning on and off the flow of powder coating material from said primary hopper to said feed hopper; a second valve, connected to said transfer line downstream from said first valve, for introducing air into said transfer line when said first valve turns off the flow of powder coating material so that the powder coating material remaining in said transfer line downstream from said first valve is transmitted into said feed hopper.
- 12. The apparatus of claim 1 in which said second transfer device comprises a gun supply hopper located proximate the powder spray booth and connected between said feed hopper and at least one powder spray device associated with the powder spray booth, and a pump connected to said feed hopper which is effective to transmit powder coating material from said powder collection into said gun supply hopper under the application of a positive pressure.
- 13. Apparatus for supplying powder coating material to at least one coating dispenser for deposition onto objects transmitted through a powder spray booth within which a portion of the powder coating material fails to adhere to the objects and forms oversprayed powder coating material, comprising:
a primary hopper containing virgin powder coating material, and at least one secondary hopper; a first feed hopper adapted to supply powder coating material to at least one spraying device associated with the powder spray booth; a first transfer device which transmits virgin powder coating material under the application of negative pressure from said primary hopper into said first feed hopper; and a second transfer device which transmits oversprayed powder coating material collected within the powder spray booth, under the application of negative pressure, into one of said primary hopper and said at least one secondary hopper.
- 14. The apparatus of claim 13 in which said first transfer device comprises:
a first powder receiver unit connected between the source of powder coating material and said primary hopper, said first powder receiver unit having a powder collection chamber communicating with said primary hopper; a first vacuum pump connected to said powder collection chamber of said first powder receiver unit to create a negative pressure therein which draws powder coating material from the source into said first powder receiver; a second powder receiver unit connected between said primary hopper and said first feed hopper, said second powder receiver unit having a powder collection chamber communicating with said first feed hopper; a second vacuum pump connected to said powder collection chamber of said second powder receiver unit to create a negative pressure therein which draws powder coating material from said primary hopper into said second powder receiver.
- 15. The apparatus of claim 13 in which said at least one secondary hopper is a reclaim hopper, said reclaim hopper being connected to a second feed hopper adapted to supply powder coating material to at least one spraying device associated with the powder spray booth.
- 16. The apparatus of claim 15 in which said second transfer device comprises:
a second powder receiver unit adapted to be connected between the powder spray booth and said reclaim hopper, said second powder receiver unit having a powder collection chamber communicating with said reclaim hopper; a second vacuum pump connected to said powder collection chamber of said second powder receiver unit to create a negative pressure therein which draws oversprayed powder coating material from the powder spray booth into said second powder receiver; a third powder receiver unit connected between said reclaim hopper and said second feed hopper, said third powder receiver unit having a powder collection chamber communicating with said third feed hopper; a third vacuum pump connected to said powder collection chamber of said third powder receiver unit to create a negative pressure therein which draws powder coating material from said reclaim hopper into said third powder receiver.
- 17. The apparatus of claim 13 in which said at least one secondary hopper is a reclaim hopper which receives oversprayed powder material from said second transfer device for selectively transferring virgin powder coating material from said primary hopper into said reclaim hopper to supplement the supply of powder coating material thereto.
- 18. The apparatus of claim 17 in which said third transfer device includes:
a sensor operative to sense the quantity of oversprayed powder coating material present within said reclaim hopper, and to produce a signal representative thereof; a pump, connected to said primary hopper, which pumps virgin powder coating material from said primary hopper to said reclaim hopper dependent on said signal.
- 19. The apparatus of claim 18 in which said sensor is a load cell which supports said reclaim hopper, said load cell being effective to sense changes in weight of the powder coating material within said reclaim hopper, corresponding to changes in the quantity of powder coating material therein, and to produce said signal in the event the weight of powder coating material within said reclaim hopper falls below a predetermined level.
- 20. Apparatus for supplying powder coating material to at least one coating dispenser for deposition onto objects transmitted through a powder spray booth within which a portion of the powder coating material fails to adhere to the objects and forms oversprayed powder coating material, comprising:
a powder kitchen which houses at least one primary hopper containing virgin powder coating material, and at least one secondary hopper; a first feed hopper adapted to be located proximate to the powder spray booth in comparison to said powder kitchen, said feed hopper being adapted to supply powder coating material to powder spray guns associated with the powder spray booth; a transfer device, operating under the application of negative pressure, which transfers oversprayed powder coating material from the powder spray booth to one of said primary and said at least one secondary hoppers, and which transfers powder coating material from one of said primary hopper and said at least one secondary hoppers to said first feed hopper.
- 21. The apparatus of claim 20 in which said powder kitchen is an enclosure having an interior which is substantially isolated from ambient air.
- 22. The apparatus of claim 20 in which said at least one secondary hopper is a reclaim hopper adapted to be connected to the powder spray booth, and wherein said apparatus further includes a second feed hopper connected to said reclaim hopper.
- 23. The apparatus of claim 22 in which said transfer device comprises:
an individual powder receiver unit associated with each of said primary hopper, said reclaim hopper and said first and second feed hoppers, each of said powder receiver units being effective to receive powder coating material from one of the source of virgin powder coating material, the powder spray booth or another hopper, and to transmit metered quantities of powder coating material to their associated hoppers; a vacuum device, connected to each of said powder receiver units, which transfers powder coating material into said powder receiver units under the application of negative pressure.
- 24. The apparatus of claim 23 in which each of said powder receiver units comprises:
a powder collection chamber for receiving powder coating material, said powder collection chamber containing a cartridge filter; a clean air chamber separated from said powder collection chamber; an air jet device for dislodging powder material from said cartridge filter; a device for transmitting a metered quantity of powder coating material from said powder collection chamber into an associated hopper.
- 25. The apparatus of claim 24 in which said device for transferring a metered quantity of powder coating material associated with each of said powder receiver units comprises:
a metering air lock connected to said powder collection chamber; and a sieve connected between said metering air lock and said primary hopper, said reclaim hopper or said first and second feed hoppers.
- 26. Apparatus for supplying powder coating material to at least one dispenser for deposition onto objects transmitted through a powder spray booth, comprising:
a primary hopper for receiving powder coating material, a first transfer device, connected to said primary hopper, which transmits powder coating material to said primary hopper; a first sensor which is effective to sense the quantity of powder coating material within said primary hopper, and to cause said first transfer device to transmit powder coating material into said primary hopper when said quantity of powder coating material falls below a predetermined amount; a feed hopper; a second transfer device, connected between said primary hopper and said feed hopper, which transmits powder coating material under the application of negative pressure from said primary hopper to said feed hopper; and a second sensor which is effective to sense the quantity of powder coating material within said feed hopper, and to operate said second transfer device when said quantity of powder coating material falls below a predetermined amount.
- 27. The apparatus of claim 26 in which said first sensor is a load cell which supports said primary hopper, said load cell being effective to sense changes in weight of the powder coating material within said primary hopper, corresponding to changes in said quantity of powder coating material therein, and to produce a signal in the event said weight falls below a predetermined level, said load cell transmitting said signal to a controller which operates said first transfer device to supply powder coating material to said primary hopper.
- 28. The apparatus of claim 27 in which said second sensor is a load cell which supports said feed hopper, said load cell being effective to sense changes in weight of the powder coating material within said feed hopper, corresponding to changes in said quantity of powder coating material therein, and to produce a signal in the event said weight falls below a predetermined level, said load cell transmitting said signal to a controller which operates said second transfer device to supply powder coating material to said feed hopper.
- 29. The apparatus of claim 28 in which each of said first and second transfer devices includes a powder receiver unit coupled to said primary hopper or to said feed hopper, said powder receiver units being supported independently of said primary hopper and said feed hopper so that said load cells associated therewith measure only the weight of powder coating material entering said primary and feed hoppers.
- 30. Apparatus for supplying powder coating material, comprising:
a hopper housing having an interior including an internal wall which forms a first powder fluidizing area and a second powder fluidizing area; a porous plate carried within said hopper housing which divides said interior thereof into a fluidized bed located above said porous plate and an air plenum below said porous plate, said hopper housing being formed with a powder inlet for introducing powder coating material into said fluidizing bed and an air inlet for introducing an upward flow of air into said air plenum beneath said porous plate; a first agitator device located within said first powder fluidizing area and a second agitator device located within said second powder fluidizing area, said first and second agitator devices creating a stable, fluidized bed of powder within said first and second fluidizing areas, respectively.
- 31. The apparatus of claim 30 in which said internal wall of said hopper housing is formed in the general shape of a FIG. 8 with two substantially circular portions which meet at a center area of reduced diameter.
- 32. The apparatus of claim 31 in which said internal wall of said housing includes opposed, triangular shaped baffles which form said center area of reduced diameter.
- 33. The apparatus of claim 30 in which each of said first and second agitator devices includes a motor driven paddle located within one of said first and second fluidizing areas above said porous plate, one of said paddles being positioned vertically above and overlapping the other of said paddles.
- 34. The apparatus of claim 30 wherein a portion of the powder coating material introduced into said interior of said hopper housing includes fines, said apparatus further including a vent connected to a vent collector operative to remove fines from said interior of said hopper housing.
- 35. The apparatus of claim 30 in which said air plenum includes baffles to direct an evenly distributed flow of air upwardly to said porous plate.
- 36. Apparatus for applying powder coating material onto objects, comprising:
a spray booth having a ceiling, floor, and opposed side walls defining an interior which provides a controlled area for the application of powder coating material onto objects moving therethrough; a powder collection device located immediately adjacent said spray booth which collects oversprayed powder from said interior thereof, said powder collection device including:
(i) powder collection units extending along substantially the length of said spray booth, each of said powder collection units having a powder collection chamber for receiving oversprayed powder from said interior of said spray booth; (ii) a clean air chamber associated with each of said powder collection units, each of said clean air chambers having an interior which is isolated from the oversprayed powder entering said powder collection chamber; (iii) a filter device located within each of said powder collection chambers and connected to said clean air chambers for collecting oversprayed powder thereon to form clean air which is introduced into said clean air chambers; a number of exhaust units, each connected to at least one powder collection unit, for creating a negative pressure within said powder collection chambers connected thereto to draw air entrained powder coating material from said spray booth into said powder collection units.
- 37. The apparatus of claim 36 in which each of said powder collection units is connected by a connector line to a common header pipe, each of said connector lines carrying a valve movable between an open position and a closed position.
- 38. The apparatus of claim 37 further including a vacuum device which is effective to apply a negative pressure within said common header pipe, and a device for sequentially opening and closing said valves associated with each of said powder collection units.
- 39. The apparatus of claim 36 in which each of said exhaust units includes an exhaust plenum and an exhaust fan, said exhaust plenum being connected by separate duct to said clean air chamber of each of said at least one powder collection unit, said exhaust fan being operative to create a negative pressure within each of said at least one powder collection unit through said exhaust plenum and said ducts.
- 40. The apparatus of claim 39 in which each of said exhaust plenums includes a number of final filters and a sensor operative to sense the pressure drop across said final filters.
- 41. The apparatus of claim 36 in which said powder collection chamber of each of said powder collection units includes a porous plate mounted at an angle relative to horizontal in position to receive powder coating material from said spray booth, said powder collection chamber being formed with an air inlet for directing a flow of air through said porous plate to fluidize powder coating material received thereon.
- 42. The apparatus of claim 36 in which said filter device includes two banks of cartridge filters mounted in an inverted V-shape within said powder collection chamber of each powder collection unit.
- 43. The apparatus of claim 42 further including a number of reverse air jet valves mounted within said clean air chamber of each powder collection unit in position above said cartridge filters, each of said reverse air jet valves being positioned in alignment with one of said cartridge filters.
- 44. Apparatus for supplying powder coating material comprising:
a hopper housing having an interior formed by a top wall, sidewall and bottom wall; a porous plate carried within said hopper housing which divides said interior thereof into a fluidized bed located above said porous plate and an air plenum below said porous plate, said hopper housing being formed with a powder inlet for introducing powder coating material into said fluidizing bed and an air inlet for introducing an upward flow of air into said air plenum beneath said porous plate; and a vertically oriented baffle located within said fluidized bed between said top wall of said hopper housing and said porous plate, said baffle being located between said powder inlet and a powder discharge tube extending into said interior of said hopper housing.
- 45. The apparatus of claim 44 further including an agitator to create a stable area of fluidized powder in the vicinity of said discharge tube.
- 46. The apparatus of claim 44 in which said discharge tube within said hopper housing is connected to a robot carrying at least one powder spray gun.
- 47. Apparatus for applying powder coating material onto objects, comprising:
a spray booth having a floor, ceiling and opposed side walls defining an interior which provides a controlled area for the application of powder coating material onto objects moving therethrough; a number of powder collection units located immediately adjacent said spray booth for collecting oversprayed powder from said interior thereof; a control device for sequentially transferring the oversprayed powder coating material, under the application of negative pressure, from said powder collection units to a common header pipe; a device for transferring the oversprayed powder coating material, under the application of negative pressure, from said common header pipe to a hopper.
- 48. The apparatus of claim 47 in which each of said powder collection units is connected by a connector line to said common header pipe, said control device including a gate valve mounted within each of said connector lines to control the flow of powder coating material therethrough.
- 49. The apparatus of claim 47 in which each of said powder collection units includes a powder collection chamber, each of said powder collection chambers including a porous plate mounted at an angle relative to horizontal in position to receive powder coating material from said spray booth, said powder collection chambers each being formed with an air inlet for directing a flow of air through said porous plate to fluidize powder coating material received thereon.
- 50. Apparatus for transferring powder coating material, comprising:
a source of virgin powder coating material; a reclaim hopper adapted to communicate with a powder spray booth, said reclaim hopper being effective to receive oversprayed powder coating material from the powder spray booth which does not adhere to objects moving therethrough; a mixing hopper connected to said source and to said reclaim hopper, said mixing hopper being adapted to communicate with at least one coating dispenser associated with the powder spray booth; a controller unit operative to direct a selected ratio of virgin powder coating material and oversprayed powder coating material from said source and from said reclaim hopper, respectively, into said mixing hopper where it is intermixed for supply to the at least one coating dispenser.
- 51. The apparatus of claim 50 in which said source of virgin powder coating material includes a primary feed hopper which receives the virgin powder coating material, said primary feed hopper being connected to at least one other coating dispenser associated with the powder spray booth.
- 52. The apparatus of claim 50 in which said powder coating material is a particulate powder coating, said controller unit being operative to accept measurements of the particle size distribution of the mixture of virgin powder coating material and reclaim powder coating material within said mixing hopper from a particle size distribution measuring device.
- 53. The apparatus of claim 52 in which said controller unit is operative to calculate the total volume percentage of powder coating material within said mixing hopper having a particle size below a selected minimum size, and to compare said calculated total volume percentage with a desired total volume percentage.
- 54. The apparatus of claim 50 in which said source of virgin powder coating material is connected to said mixing hopper by at least one line carrying a first valve, and said reclaim hopper is connected to said mixing hoper by at least one line carrying a second valve, said controller unit being operative to open and close said first and second valves to control the quantity of virgin and reclaim powder coating material entering said mixing hopper.
- 55. The apparatus of claim 50 in which said mixing hopper comprises:
a hopper housing having an interior including an internal wall which forms a first powder fluidizing area and a second powder fluidizing area; a porous plate carried within said hopper housing which divides said interior thereof into a fluidized bed located above said porous plate and an air plenum located below said porous plate, said hopper housing being formed with a powder inlet for introducing powder coating material into said fluidized bed and an air inlet for introducing an upward flow of air into said air plenum beneath said porous plate; a first agitator located within said first powder fluidizing area and second agitator located within said second powder fluidizing area, said first and second agitators being effective to create a stable, fluidized bed of powder within said first and second fluidizing areas, respectively.
- 56. The apparatus of claim 55 in which said internal wall of said hopper housing is formed in the general shape of a FIG. 8 with two substantially circular portions which meet at a center area of reduced diameter.
- 57. The apparatus of claim 56 in which said internal wall of said housing includes opposed, triangular shaped baffles which form said center area of reduced diameter.
- 58. The apparatus of claim 55 in which each of said first and second agitators includes a motor driven paddle located within one of said first and second fluidizing areas above said porous plate, one of said paddles being positioned vertically above and overlapping the other of said paddles.
- 59. The apparatus of claim 55 wherein a portion of the powder coating material introduced into said interior of said hopper housing includes fines, said apparatus further including a vent connected to a vent collector operative to remove at least a portion of said fines from said interior of said hopper housing.
- 60. The apparatus of claim 55 in which said air plenum includes baffles to direct an evenly distributed flow of air upwardly to said porous plate.
- 61. Apparatus for transferring particulate powder coating material, comprising:
a primary feed hopper connected to a source of virgin particulate powder coating material, said primary feed hopper communicating with at least one first coating dispenser which is effective to apply the virgin particulate powder coating material onto an object moving through a powder spray booth; a reclaim hopper adapted to communicate with the powder spray booth, said reclaim hopper being effective to receive oversprayed particulate powder coating material from the powder spray booth which does not adhere to objects moving therethrough; a mixing hopper connected to said primary hopper to receive virgin particulate powder coating material and to said reclaim hopper to receive oversprayed particulate powder coating material, said mixing hopper communicating with at least one second coating dispenser which is effective to apply a mixture of virgin particulate powder coating material and oversprayed particulate powder coating material onto the object moving through the powder spray booth; a controller unit operative to control the supply of virgin particulate powder coating material and oversprayed particulate powder coating material into said mixing hopper so that the total volume of powder particles within said mixing hopper which are less than a selected, minimum size does not exceed a predetermined maximum percentage.
- 62. The apparatus of claim 50 in which said powder coating material is a particulate powder coating, said controller unit being operative to accept measurements of the particle size distribution of the mixture of virgin powder coating material and reclaim powder coating material within said mixing hopper from a particle size distribution measuring device.
- 63. The apparatus of claim 62 in which said controller unit is operative to calculate the total volume percentage of powder coating material within said mixing hopper having a particle size below a selected minimum size, and to compare said calculated total volume percentage with a desired total volume percentage.
- 64. The apparatus of claim 61 in which said primary feed hopper is connected to said mixing hopper by at least one line carrying a first valve, and said reclaim hopper is connected to said mixing hoper by at least one line carrying a second valve, said controller unit being operative to open and close said first and second valves to control the quantity of virgin powder coating material and reclaim powder coating material entering said mixing hopper.
- 65. Apparatus for applying powder coating material objects, comprising:
a powder spray booth having opposed sidewalls, a floor and a ceiling defining a controlled area within which to powder coat objects moving therethrough; at least one coating dispenser operative to apply powder coating material onto objects within said powder spray booth; a source of virgin powder coating material; a reclaim hopper connected to said powder spray booth, said reclaim hopper being effective to receive oversprayed powder coating material from said powder spray booth which does not adhere to objects moving therethrough; a mixing hopper connected to said source and to said reclaim hopper, said mixing hopper being connected to said at least one coating dispenser associated with the powder spray booth; a controller unit operative to direct a selected ratio of virgin powder coating material and oversprayed powder coating material from said source and from said reclaim hopper, respectively, into said mixing hopper where it is intermixed for supply to said at least one coating dispenser.
- 66. The apparatus of claim 65 in which said source of virgin powder coating material includes a primary feed hopper which receives the virgin powder coating material, said primary feed hopper being connected to at least one other coating dispenser associated with the powder spray booth.
- 67. The apparatus of claim 65 in which said powder coating material is a particulate powder coating, said controller unit being operative to accept measurements of the particle size distribution of the mixture of virgin powder coating material and reclaim powder coating material within said mixing hopper from a particle size distribution measuring device.
- 68. The apparatus of claim 67 in which said controller unit is operative to calculate the total volume percentage of powder coating material within said mixing hopper having a particle size below a selected minimum size, and to compare said calculated total volume percentage with a desired total volume percentage.
- 69. The apparatus of claim 65 in which said source of virgin powder coating material is connected to said mixing hopper by at least one line carrying a first valve, and said reclaim hopper is connected to said mixing hopper by at least one line carrying a second valve, said controller unit being operative to open and close said first and second valves to control the quantity of virgin and reclaim powder coating material entering said mixing hopper.
- 70. The apparatus of claim 65 in which said source of virgin powder material includes a primary feed hopper, each of said primary feed hoppers, said reclaim hopper and said mixing hopper comprising:
a hopper housing having an interior including an internal wall which forms a first powder fluidizing area and a second powder fluidizing area; a porous plate carried within said hopper housing which divides said interior thereof into a fluidized bed located above said porous plate and an air plenum located below said porous plate, said hopper housing being formed with a powder inlet for introducing powder coating material into said fluidized bed and an air inlet for introducing an upward flow of air into said air plenum beneath said porous plate; a first agitator located within said first powder fluidizing area and second agitator located within said second powder fluidizing area, said first and second agitators being effective to create a stable, fluidized bed of powder within said first and second fluidizing areas, respectively.
- 71. The apparatus of claim 70 in which said internal wall of said hopper housing is formed in the general shape of a FIG. 8 with two substantially circular portions which meet at a center area of reduced diameter.
- 72. The apparatus of claim 71 in which said internal wall of said housing includes opposed, triangular shaped baffles which form said center area of reduced diameter.
- 73. The apparatus of claim 70 in which each of said first and second agitators includes a motor driven paddle located within one of said first and second fluidizing areas above said porous plate, one of said paddles being positioned vertically above and overlapping the other of said paddles.
- 74. The apparatus of claim 70 wherein a portion of the powder coating material introduced into said interior of said hopper housing includes fines, said apparatus further including a vent connected to a vent collector operative to remove at least a portion of said fines from said interior of said hopper housing.
- 75. The apparatus of claim 70 in which said air plenum includes baffles to direct an evenly distributed flow of air upwardly to said porous plate.
- 76. Apparatus for supplying powder coating material to coating dispensers for deposition onto objects transmitted through a powder spray booth, comprising:
a primary hopper; a feed hopper, including: (i) a hopper housing having an interior formed by a top wall, sidewall and bottom wall; (ii) a porous plate carried within said hopper housing which divides said interior thereof into a fluidized bed located above said porous plate and an air plenum below said porous plate, said hopper housing being formed with a powder inlet connected to said primary hopper and an air inlet for introducing an upward flow of air into said air plenum beneath said porous plate; and (iii) a transfer tube connected to said fluidized bed and being adapted to communicate with at least one coating dispenser; a first transfer device, connected between said primary hopper and said feed hopper, which transmits powder coating material under the application of negative pressure from said primary hopper to said feed hopper.
- 77. The apparatus of claim 76 in which said hopper housing of said feed hopper is connected to a vacuum pump which is operative to draw powder coating material from said primary hopper into said hopper housing.
- 78. The apparatus of claim 76 in which said transfer tube of said feed hopper includes a valve.
- 79. Apparatus for supplying powder coating material to coating dispensers for deposition onto objects transmitted through a powder spray booth, comprising:
a primary hopper; first and second feed hoppers, each including: (i) a hopper housing having an interior formed by a top wall, sidewall and bottom wall; (ii) a porous plate carried within said hopper housing which divides said interior thereof into a fluidized bed located above said porous plate and an air plenum below said porous plate, said hopper housing being formed with a powder inlet and an air inlet for introducing an upward flow of air into said air plenum beneath said porous plate; and (iii) a transfer tube carrying a valve; a first transfer device connected to said first feed hopper which transmits powder coating material under the application of negative pressure from a source of coating material into said first feed hopper, said transfer tube of said first feed hopper being connected to said primary hopper; a second transfer device connected to said second feed hopper which transmits powder coating material under the application of negative pressure from said primary hopper into said second feed hopper, said transfer tube of said second feed hopper being adapted to communicate with at least one spray gun.
- 80. The apparatus of claim 79 in which said transfer tube of said first feed hopper extends generally vertically downwardly from said first feed hopper to said primary hopper so that powder coating material from said first feed hopper can fall by gravity through said transfer tube into said primary hopper.
- 81. A method of applying powder coating material onto objects moving through a powder spray booth, comprising:
transmitting powder coating material under the application of negative pressure from a primary hopper containing the powder coating material to a feed hopper; transmitting powder coating material from the feed hopper to at least one powder spray device associated with the powder spray booth.
- 82. The method of claim 81 further including the step of transmitting powder coating material under the application of negative pressure from a source into the primary hopper.
- 83. The method of claim 82 in which said step of transmitting powder coating material under the application of negative pressure from a source into the primary hopper includes transmitting the powder coating material from the source into the powder collection chamber of a powder receiver unit associated with the primary hopper, and then transferring a metered quantity of the powder coating material from the powder collection chamber into the primary hopper.
- 84. The method of claim 83 in which said step of transferring a metered quantity of powder coating material comprises operating an air lock metering device connected to the powder collection chamber to transfer a metered quantity of powder coating material therefrom to a sieve coupled to the primary hopper.
- 85. The method of claim 81 in which said step of transmitting powder coating material under the application of negative pressure from the primary hopper into the feed hopper includes transmitting the powder coating material from the primary hopper into the powder collection chamber of a powder receiver unit associated with the feed hopper, and then transferring a metered quantity of the powder coating material from the powder collection chamber into the feed hopper.
- 86. The method of claim 85 in which said step of transferring a metered quantity of powder coating material comprises operating an air lock metering device connected to the powder collection chamber to transfer a metered quantity of powder coating material therefrom to a sieve coupled to the feed hopper.
- 87. The method of claim 81 in which said step of transmitting powder coating material from the feed hopper to at least one powder spray device comprises pumping powder coating material under the application of positive pressure to the spray device.
- 88. The method of claim 81 in which said step of transmitting powder coating material from the feed hopper to at least one powder spray device comprises pumping powder coating material under the application of positive pressure to a robot hopper associated with a robot operative to manipulate one or more spray devices within the powder spray booth.
- 89. A method of applying powder coating material onto objects moving through a powder spray booth, comprising:
transmitting powder coating material under the application of negative pressure from a primary hopper to a first feed hopper located proximate the powder spray booth; transmitting oversprayed powder coating material under the application of negative pressure from a powder collection and recovery system associated with the powder spray booth into one of a primary hopper and a secondary hopper; transmitting the oversprayed powder coating material under the application of negative pressure from said one of the primary and secondary hoppers to a second feed hopper located proximate the powder spray booth; transmitting powder coating material from the first and second feed hoppers to separate powder spray devices associated with the powder spray booth.
- 90. The method of claim 89 in which said step of transmitting oversprayed powder coating material under the application of negative pressure from a powder collection and recovery system comprises:
collecting oversprayed powder coating material in a number of individual powder collection units associated with the powder spray booth; sequentially transferring the collected, oversprayed powder coating material from the powder collection units into a common header pipe; and transferring the oversprayed powder coating material from the header pipe into said one of the primary and secondary hoppers.
- 91. The method of claim 90 in which said step of sequentially transferring the collected, oversprayed powder coating material comprises sequentially opening gate valves carried within connector lines extending between each of the powder collection units and the common header pipe.
- 92. The method of claim 89 in which said step of transmitting oversprayed powder coating material under the application of negative pressure from a powder collection and recovery system comprises transmitting the oversprayed powder coating material into a reclaim hopper separate from the primary hopper.
- 93. The method of claim 92 in which said step of transmitting powder coating material from the first and second feed hoppers comprises transmitting virgin powder coating material supplied to the first feed hopper by the primary hopper to powder spray devices, and transmitting oversprayed powder coating material supplied to the second feed hopper by the reclaim hopper to powder spray devices.
- 94. A method of applying powder coating material onto objects moving through a powder spray booth, comprising:
transmitting powder coating material under the application of negative pressure from a primary hopper to a feed hopper located proximate the powder spray booth; transmitting powder coating material from the feed hopper to at least one powder spray device associated with the powder spray booth; monitoring the quantity of powder coating material within the feed hopper, and transmitting additional powder coating material from the primary hopper into the feed hopper whenever the quantity of powder coating material within the feed hopper falls below a predetermined level.
- 95. The method of claim 94 in which said step of monitoring the weight of powder coating material within the feed hopper comprises monitoring signals representative of the weight of powder coating material within the feed hopper produced by a load cell which supports the feed hopper, and activating a transfer means to supply powder coating material to the feed hopper under the application of negative pressure in response to the signals.
- 96. The method of claim 94 further including the step of transmitting powder coating material from a source into the primary hopper.
- 97. The method of claim 96 in which said step of transmitting the powder coating material from the source includes:
monitoring the weight of powder coating material within the primary hopper; and transmitting additional powder coating material from, the source into the primary hopper whenever the weight of powder coating material within the primary hopper falls below a predetermined level.
- 98. A method of applying powder coating material onto objects moving through a powder spray booth, comprising:
transmitting virgin powder coating material under the application of negative pressure from a primary hopper to a first feed hopper located proximate the powder spray booth; transmitting oversprayed powder coating material under the application of negative pressure from a powder collection and recovery system associated with the powder spray booth into a reclaim hopper positioned at a remote location from the powder spray booth; transmitting the oversprayed powder coating material under the application of negative pressure from the reclaim hopper to a second feed hopper located proximate the powder spray booth; transmitting virgin powder coating material from the first feed hopper and oversprayed powder coating material from the second feed hopper to separate powder spray devices associated with the powder spray booth; monitoring the weight of virgin powder coating material within the first feed hopper, and transmitting additional virgin powder coating material from the primary hopper into the first feed hopper whenever the weight of virgin powder coating material within the first feed hopper falls below a predetermined level; and monitoring the weight of oversprayed powder coating material within the second feed hopper, and transmitting additional oversprayed powder coating material from the reclaim hopper into the second feed hopper whenever the weight of oversprayed powder coating material within the second feed hopper falls below a predetermined level.
- 99. The method of claim 98 further including the step of monitoring the weight of oversprayed powder coating material within the reclaim hopper.
- 100. The method of claim 99 in which said step of monitoring the weight of oversprayed powder coating material within the reclaim hopper further includes transferring virgin powder coating material from the primary hopper into the reclaim hopper in the event sufficient oversprayed powder coating material is not available from the powder collection and recovery system of the powder spray booth.
- 101. A method of collecting and recovering oversprayed powder coating material from the interior of a powder spray booth, comprising:
creating a negative pressure within the interior of the powder spray booth; drawing air entrained powder coating material from the booth interior into a number of individual powder collection units located beneath the floor of the powder spray booth; sequentially transferring the oversprayed powder coating material, under the application of negative pressure, from the powder collection units into a common header pipe; transferring the oversprayed powder coating is material, under the application of negative pressure, from the common header pipe to a hopper.
- 102. The method of claim 101 in which said step of creating a negative pressure within the interior of the powder spray booth comprises activating a number of individual blower units each associated with at least one powder collection unit, each blower unit being effective to create a negative pressure within its associated powder collection unit and within the booth interior.
- 103. The method of claim 101 in which said step of sequentially transferring the collected, oversprayed powder coating material from the powder collection units comprises sequentially opening gate valves each carried within a connector line extending between one of the powder collection units and the common header pipe.
- 104. The method of applying particulate powder coating material onto objects moving through a powder spray booth, comprising:
discharging virgin particulate powder coating material from one or more coating dispensers communicating with a powder source onto objects moving through the powder spray booth; transferring oversprayed particulate powder coating material, which does not attach to the objects within the spray booth, from the powder spray booth into a reclaim hopper; directing virgin particulate powder material from the powder source, and oversprayed particulate powder material from the reclaim hopper, into a mixing hopper; controlling the ratio of virgin particulate powder material and oversprayed particulate powder material introduced into the mixing hopper so that the volume of powder particles which are less than a selected minimum particle size do not exceed a predetermined percentage of the total volume of particulate powder coating material within the mixing hopper.
- 105. The method of claim 104 in which said step of controlling the ratio comprises:
measuring the particle size distribution of the particulate powder material within the mixing hopper; determining the volume percentage of powder particles which are less than a selected minimum particle size; comparing the determined volume percentage with a desired percentage; and adjusting the supply of the virgin particulate powder material directed into the mixing hopper dependent upon said comparison.
- 106. The method of claim 105 in which said step of adjusting the supply of virgin particulate powder coating material further comprises the steps of:
(a) comparing the actual quantity of particulate powder coating material within the mixing hopper with the total capacity of the mixing hopper to determine the available capacity within the mixing hopper; (b) comparing the available capacity within the mixing hopper with the desired quantity of virgin particulate powder material to be added to the mixing hopper; (c) adding the desired quantity of virgin particulate powder coating material to the mixing hopper; (d) removing particulate powder coating material from the mixing hopper, prior to performing step (c), in the event the available capacity within the mixing hopper is less than the desired quantity of virgin particulate powder coating material to be added.
- 107. The method of supplying a mixture of virgin powder coating material and reclaim powder coating material to at least one coating dispenser, comprising:
measuring the particle size distribution of the virgin powder coating material; measuring the particle size distribution of the reclaim powder coating material collected after an initial application of the virgin powder coating material onto a given part; calculating a probability factor for each particle size range within the particle size distribution, each of said probability factors being representative of the probability that particles within a respective particle size range will be collected as reclaim powder material after a coating operation; calculating the particle size distribution of a mixture of said reclaim powder coating material and a selected fraction of virgin powder coating material using said probability factors.
- 108. The method of claim 107 in which said step of calculating a probability factor for each particle size range includes performing the following calculations:
- 109. The method of claim 108 in which said step of calculating the probability factor for each particle size range further includes empirically determining a numeric adjustment factor FA so that the product of the measured particle size distribution of the virgin powder coating material, Fv, and the probability factor, P, is substantially equal to the measured particle size distribution of the reclaim powder coating material, Fr.
- 110. The method of claim 108 in which said step of calculating the particle size distribution of a mixture of reclaim powder coating material and a selected fraction of virgin powder coating material includes the following calculation:
Parent Case Info
[0001] This is a Continuation-In-Part of U.S. patent application Ser. No. 08/066,873, filed May 25, 1993, to Shutic et al. entitled Vehicle Powder Coating System, which is owned by the assignee of this invention.
Continuations (1)
|
Number |
Date |
Country |
Parent |
10041201 |
Jan 2002 |
US |
Child |
10752809 |
Jan 2004 |
US |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
08066873 |
May 1993 |
US |
Child |
10041201 |
Jan 2002 |
US |