Abstract: An improved powder material processing apparatus is described herein, in which a plurality of wire-shaped electrodes are disposed within an imaginary plane at an equal interval and in parallel to each other. An insulator layer is interposed between the adjacent wire-shaped electrodes to prevent spark discharge from being generated by an A.C. high voltage applied between the adjacent wire-shaped electrodes. A silent discharge region is established between said adjacent wire-shaped electrodes, and positive and negative charges are separately given to the particles forming said powder material by making uncharged powder material pass through said silent discharge region, resulting in formation of powder material consisting of substantially equal numbers of positively charged particles and negatively charged particles, whereby control characteristics of the processed powder material can be greatly improved and the above-mentioned charging process can be effected continuously at a high efficiency.

Abstract: An improved electrode assembly for a high-intensity ionizer array utilized as the first stage in a two-stage electrostatic precipitator. Each ionizer unit employs a pair of co-axial electrodes to create a high-intensity electric field across the path of a particulate-laden gas stream. As the gas passes through the field it is intensely ionized and the particulate becomes highly charged. The ionizer anode comprises a venturi diffuser through which the gas stream flows immediately prior to entry into a precipitator stage which removes the charged particles. The ionizer cathode is a disk co-axially mounted within the venturi throat and having an arcuate periphery. A high voltage power supply connected between the anode and cathode establishes a high-intensity corona discharge in the annular region formed between the periphery of the cathode disk and the surrounding cylindrical anode surface. The section of the venturi wall in the area of the cathode disk is formed with a series of axially spaced conical vanes.

Abstract: Disclosed is an electrostatic coating device and method employing highly charged particles that are charged remote from the articles to be coated and then delivered to an area where they are to be applied by conveying them in a moving air stream. The movement is stopped by closing off the air stream, suspending the particles in space. Thereafter the particles are applied to an article by electrostatics. Special components are a powder entraining device which uses air fed at the bottom to erode the powder, feeds additional air from above and removes entrained powder from below; a charging device using the reaction of two converging opposed vortexes to oscillate the powder turbulently through an isolated high voltage electrical zone; and a multiple valve that feeds the charged powder to a can and vents the can, then isolates the can, bypassing the powder.

Abstract: A corona discharger includes a shield and a discharge wire extended between opposed ends of the shield and supported between its ends. The position of the wire is adjustable to control the distance between the wire and a surface of a member to be subjected to the corona discharge and a spring is arranged to maintain tension on the discharge wire regardless of the position of adjustment of the wire.

Abstract: A power grid for a fluidized bed for electrostatically depositing a powdered plastic coating material from the bed onto an elongated metal substrate moving in a path of travel above the upper surface of the bed on a substantially horizontal pass line. The power grid includes two co-planar wire mesh elements positioned beneath the surface of the bed, the elements having opposed edges in parallel spaced relationship and defining a gap therebetween beneath the pass line. The edges are upturned to form a plurality of electrode segments, the tips of the electrode segments being substantially coincident with the upper surface of the bed when energized. In operation the electrode segments form a row of localized corona discharges to either side of the passing substrate to effect electrostatic deposition of a thin uniform film coating of the powdered material thereon.

Abstract: In a pair of surface-shaped silent discharge electrodes opposed to each other and separated by a predetermined space therebetween, phases of alternating voltages are applied to said respective silent discharge electrodes shifted in phase with respect to each other so that a silent discharge may arise alternately on either one of the electrode surfaces. A second alternating voltage is applied between the silent discharge electrodes and is alternatingly varied at a fundamented frequency twice as high as the frequency of the first alternating voltages applied to said surface-shaped silent discharge electrodes and is not inverted in polarity during the period when the silent discharge exists on either one of the electrode surfaces. Powder particles are passed through the space which separates the pair of surface-shaped silent discharge electrodes and charged in either positive or negative polarity continuously at a high efficiency.