Abstract:
A spray gun with a powder spray nozzle sprays a pattern of coating material through specified discharge slot configurations to evenly coat a recess and/or the surface of a substrate. One discharge slot configuration, having two intersecting slots disposed at substantially sixty degree angles to each other, can be rotated to change the width of the coating being applied within the recess. The other slot configuration, having at least five radial slots and a substantially circular bore extending through the intersection of the slots, is effective to coat both the recess and the flat surface of the substrate.
Abstract:
A color changer has a common feed passage that is connected to two or more inlet passages. The common feed passage can be reverse purged in a direction that is opposite a direction of powder flow through the common feed passage. A valve element seals a supply port that connects the inlet passage to the common feed passage to eliminate dead space and form a near bore line seal. The valve element is an elastic material that expands in response to applied compressed air inside the valve element.
Abstract:
A nozzle assembly for a material application device includes an expansion chamber for slowing down the velocity of powder fed to the nozzle from a dense phase pump. The nozzle assembly includes a nozzle insert that forms the expansion chamber and provides air assist function. The nozzle includes an integral deflector, and further includes a passageway for a charging electrode so that the electrical path is routed away from the powder path, while permitting the electrode tip to be centered in the powder spray pattern from the nozzle. The nozzle also includes air wash for the electrode. The nozzle outlet orifice has a cross-sectional area that is equal to or greater than the inlet cross-sectional area so that a slow moving dense phase powder cloud is produced by the nozzle.
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.
Abstract:
Apparatus and method for electrostatic charging of a container for an electrostatic coating operation includes a support member for supporting a container during an electrostatic coating operation with the support member comprising a non-metallic conductive material or electrically semiconductive portion that directly contacts a surface of the container. The electrically semiconductive portion comprises non-metallic, resistive or low conductivity material and is coupled to a source of electrical energy such that the container is electrostatically charged to an opposite polarity to offset or reduce electrostatic charge build up produced by the electrostatic coating operation.
Abstract:
A dense phase powder coating system includes a powder supply, dense phase pump, a spray gun and a diverter valve that can be used to select between conveying powder to the spray gun or circulating the powder back to the powder supply. The diverter valve may include two pneumatically actuate valve members. In one embodiment, the powder spray gun applies powder coating material to inside surfaces of a tubular container. A spray nozzle concept also is presented having a nozzle body with a conical deflector. The spray nozzle provides an uninterrupted flow between spray nozzle outlet holes and a deflector surface. The deflector may be integrally machined with the nozzle body to provide a one piece spray nozzle.
Abstract:
A pump for particulate material includes a pump chamber wherein material flows into the pump chamber under negative pressure and flows out of the pump chamber under positive pressure. A plurality of pinch valves are provided to control flow of material into and out of the pump chamber. The pinch valves are operated independent of each other and of the pump cycle rate. A modular design of the pump is provided. A pump control feature is provided for air flow rate control during positive and negative pressure conditions.
Abstract:
A dense phase powder pump includes a valve body that houses one or more pinch valve elements. The valve body comprises a sufficiently transparent material to allow an operator to visually observe operation of the pinch valves.
Abstract:
A supply or feed center for dry particulate material is modular in design with an application module and an exhaust module, along with optimal cabinet modules such as a pump cabinet module. The application module is partitioned into an application section and a utility section, both of which communicate with the exhaust module. An air diverter may be used to change relative air flow into the two sections, and in one embodiment is a swingable door. The exhaust module may include a self-contained exhaust system including after filters, motor, fan and final filters, or may share energy from a remote exhaust system. An inventive suction device is also provided to extract material from a hopper.
Abstract:
A nozzle assembly for a material application device includes an expansion chamber for slowing down the velocity of powder fed to the nozzle from a dense phase pump. The nozzle assembly includes a nozzle insert that forms the expansion chamber and provides air assist function. The nozzle includes an integral deflector, and further includes a passageway for a charging electrode so that the electrical path is routed away from the powder path, while permitting the electrode tip to be centered in the powder spray pattern from the nozzle. The nozzle also includes air wash for the electrode. The nozzle outlet orifice has a cross-sectional area that is equal to or greater than the inlet cross-sectional area so that a slow moving dense phase powder cloud is produced by the nozzle.