# US 8,783,208 B2 · Powder hopper with quiet zone, a combination of a powder hopper and a powder spray gun and a method of operating a powder hopper > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,783,208 B2 - Document ID: US8783208B2 - Status: Granted - Kind: B2 - Application number: 13/140,066 - Filed: 2009-12-16 - Published: 2012-01-26 - Granted: 2014-07-22 - Earliest claimed: 2008-12-17 - Assignees: Nordson Corporation - Applicants: Joseph G. Schroeder; Terrence M. Fulkerson; Angelo Bellini; Ralf Scheuffgen; Claus Ruschitzka - Inventors: Joseph G. Schroeder; Terrence M. Fulkerson; Angelo Bellini; Ralf Scheuffgen; Claus Ruschitzka - Web page: https://patentgrep.com/patent/US8783208B2 ## CPC - B05D 1/12: Applying particulate materials (B05D1/06, B05D1/10 take precedence) - B05B 5/032: {for spraying particulate materials} - B05B 7/1445: {involving vibrations (B05B7/145 takes precedence)} - B05B 7/1463: {the means for supplying particulate material comprising a gas inlet for pressurising or avoiding depressurisation of a powder container} - B05B 7/1472: {Powder extracted from a powder container in a direction substantially opposite to gravity by a suction device dipped into the powder} - B05B 7/1477: {means for supplying to several spray apparatus} - B05B 13/069: {the hollow bodies having a closed end} - B05B 15/25: using moving elements, e.g. rotating blades - B05D 1/06: Applying particulate materials - B05B 1/14: with multiple outlet openings (B05B1/02, B05B1/26 take precedence); with strainers in or outside the outlet opening - B05B 13/0627: {Arrangements of nozzles or spray heads specially adapted for treating the inside of hollow bodies (B05B13/0645 takes precedence)} - B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02) - B05B: SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES (spray-mixers with nozzles B01F25/72; processes for applying liquids or other fluent materials to surfaces by spraying B05D) ## Abstract A powder hopper is provided with a low turbulence zone for supplying powder to a spray gun. The low turbulence zone is defined by a baffle inside the hopper with the low turbulence zone being within a volume of the baffle, and an annular zone between the baffle and the hopper is used to bulk feed powder into the hopper. The low turbulence zone may alternatively be in the annular zone with powder added to the volume of the baffle. One preferred application for this hopper is in connection with the use of fine powder coating materials to coat the interior of small diameter cans. ## Claims ### Claim 1 A powder coating system having a hopper for powder coating material, comprising: a hopper body comprising a cylinder, a cover at an upper end of the hopper body, a fluidizing bed at a lower end of the hopper body, a baffle inside the hopper body and extending towards the fluidizing bed, the baffle comprising a cylinder of smaller diameter than the diameter of the cylinder of the hopper body so as to form an annular region between the hopper body and the baffle, at least one powder inlet disposed to feed powder into the hopper body, the powder inlet being disposed in the annular region, the baffle defining a zone inside the baffle, a powder outlet for removing powder from the zone inside the baffle. ### Claim 2 (depends on 1) The powder coating system of claim 1 wherein a lower gap is provided between the bottom of the baffle and the fluidizing bed, and an upper gap is provided between the baffle and the cover. ### Claim 3 (depends on 1) The powder coating system of claim 1 comprising an agitator disposed in the hopper, the agitator being operable to stir fluidized powder in the hopper. ### Claim 4 A powder coating system having a hopper for powder coating material, comprising: a hopper body comprising a cylinder a cover at an upper end of the hopper body, a fluidizing bed at a lower end of the hopper body, a baffle inside the hopper body and extending towards the fluidizing bed, the baffle comprising a cylinder of smaller diameter than the diameter of the cylinder of the hopper body so as to form an annular region between the hopper body and the baffle, at least one powder inlet disposed to feed powder into the hopper body, the powder inlet being disposed in the annular region, the baffle defining a zone enclosed within the baffle, a powder outlet for removing powder from the zone enclosed within the baffle, a pump connected to the powder outlet, and a powder spray gun connected to the pump. ### Claim 5 (depends on 4) The powder coating system of claim 4 wherein a lower gap is provided between the bottom of the baffle and the fluidizing bed, and an upper gap is provided between the baffle and the cover. ### Claim 6 (depends on 4) The powder coating system of claim 4 comprising an agitator disposed in the hopper, the agitator being operable to stir fluidized powder in the hopper. ### Claim 7 (depends on 4) The powder coating system of claim 4 wherein the spray gun is mounted on a reciprocator to reciprocate the gun into and out of a container. ### Claim 8 (depends on 4) The powder coating system of claim 4, wherein the spray gun has a nozzle, the nozzle comprising a plurality of discrete flow passages disposed about a longitudinal axis of the nozzle, and further comprising an electrode, the electrode extending through the nozzle along a longitudinal axis of the nozzle. ### Claim 9 (depends on 8) The combination of claim 8 wherein the discrete flow passages are disposed uniformly about a tip of the electrode that extends from an outlet end of the nozzle. ### Claim 10 A hopper for powder coating material, comprising: a hopper body comprising a cylinder a cover at an upper end of the hopper body, a fluidizing bed at a lower end of the hopper body, a baffle inside the hopper body and extending towards the fluidizing bed, the baffle comprising a cylinder of smaller diameter than the diameter of the cylinder of the hopper body so as to form an annular region between the hopper body and the baffle, at least one powder inlet disposed to feed powder into the hopper body, the powder inlet being disposed in the annular region, the baffle defining a zone enclosed within the baffle, a powder outlet for removing powder from the zone enclosed within the baffle. ### Claim 11 (depends on 10) The hopper of claim 10 wherein a lower gap is provided between the bottom of the baffle and the fluidizing bed, and an upper gap is provided between the baffle and the cover. ### Claim 12 (depends on 10) The hopper of claim 10 comprising an agitator disposed in the hopper, the agitator being operable to stir fluidized powder in the hopper.