Canadian Patents & Development Ltd.

Nordson Corporation

The University of Western Ontario

The Scott-fetzer Company

Blue Circle Industries Plc

S. C. Johnson Son, Inc.

Ciba-geigy Ag

The L.d. Kichler Co.

Atofina

Inco Limited

Quebec Metal Powders Limited

Elstat Limited

Ion I Inculet

G S Castle

James D Brown

George S Castle

Robert T Plunkett

Mark E Wefler

John R Lackner

David A Tomkins

James C Murphy

Cedric Briens

Nicholas M Hepher

Terry E Base

William J Middleton

Yuji Murata

Ariel Bru

Stig Lundquist

Kenneth J Hodgson

Anna K Norberg

Arnaud Tedoldi

Peter Hansen

Benoit Port

John L Sullivan

The present invention relates to as triboelectric fluidized bed method and apparatus for coating an object with powder prior to heating to form a coating. The methods includes arranging a bed of fluidixed powder in a vat where the powder can be charged by a tribocharging device such as a honeycomb comprising prisms or vertical tubes open at both ends.

Triboelectric fluidizded bed method and apparatus for coating an object

Tribo-electrification of conveyed particles in a pipeline of a pneumatic conveying system is reduced by electrically isolating at least one portion of the inner surface of the pipeline, preferably the concave interior surface of at least one elbow. The isolated portion acquires an electric charge of opposite polarity to that of the conveyed particles.

Reduction of electrostatic charging of particles in pneumatic conveying

A method of making a metal composite part by compacting a metal powder composition in a die whose wall surfaces have been electrostatically coated with a lubricant, thereby eliminating or reducing a lubricant in the metal powder composition, resulting in a metal composite having greater density and strength. The method further includes providing an electrostatic charge to the metal powder composition. A powder metallurgy apparatus is also provided.

Powder metallurgy apparatus and process using electrostatic die wall

An on board electrostatic filter for a vacuum cleaner is disclosed. The filter includes a pair of conductive filaments insulated from one another and disposed close together in a substantially parallel, side-by-side relationship. Circuitry is provided for applying an electrical potential difference between the two conductors. This dual filament conductor is preferably packed into a relatively small volume in a tortuous configuration, to form a random mesh, or can be oriented in a more regular serpentine configuration. Other embodiments describe the mesh electrostatic filter to purify air in an HVAC system.

Electrostatic particle filtration

An actuator for electrically charging an aerosol spray has an inductor located adjacent to the spray nozzle to induce a charge on the atomized fluid. Charge to the inductor is provided by a piezoelectric crystal which is stressed by movement of an operating member to open the spray valve. Inductor charging utilizes negligible electrical power so that additional power sources are not required. The crystal may be stressed continuously such as by squeezing, or intermittently, such as by striking. When an intermittent stressing is utilized, the electrical circuit includes a switch between the crystal and inductor which is opened as the valve is opened to isolate electrically the inductor during spraying.

Actuators for electrostatically charged aerosol spray systems

An on board electrostatic filter for a vacuum cleaner is disclosed. The filter includes a pair of conductive filaments insulated from one another and located close together in a substantially parallel, side-by-side relationship. Circuitry is provided for applying an electrical potential difference between the two conductors. This dual filament conductor is preferably packed into a relatively small volume in a tortuous configuration, to form a random mesh, or can be oriented in a more regular serpentine configuration. Other embodiments describe the mesh electrostatic filter to purify air in an HVAC system.

A mixture of particles of plastic materials having different work functions is fed through a rotating tube. The tube rotates about an axis which is inclined slightly to the horizontal. The tube is of plastic or metallic material, preferably having a rib for stirring the mixture. As the particles pass progressively down the length of the tube, the triboelectrically induced charge progressively increases, whereby the particles are highly charged upon emerging from the tube. The tube may be made of the same material as a minority component of the mixture to bring up the level of the charge on the majority component.

Electrostatic separation of mixed plastic waste

A method and apparatus for electrostatically spraying conductive coating material onto objects, primarily large extended objects, by charging with a relatively large charge the space behind the surface to be coated. With hollow objects, such as automobile bodies, the space within the body is charged. The space is charged by spraying an electrostatically charged atomized water mist into the space which evaporates charging the space and object surface. An electrostatic field is produced between the surface and the gun which, along with the supply of conductive material to which it is connected, is grounded. The gun discharges a film of coating which is atomized into droplets. The field inductively charges the film fringe and thus the droplets which are then attracted onto the large charged surface.

Space charge electrostatic coating method and apparatus

A vacuum cleaner is disclosed having an on-board electrostatic filtration device for removing ultra fine particles from the suction air stream which is discharged into the vacuum cleaner's dirt collection receptacle. The electrostatic filtration device includes a finely woven conductive mesh made from two electrically insulated sets of conductive filaments between which a low voltage electrical potential difference is applied. The polarity of the electrical potential difference is periodically reversed at low frequency to assist in maintaining filtering effectiveness notwithstanding the accumulation on the mesh of significant amounts of retained particulate matter. High permitivity material is incorporated between filaments to enhance electric fields in the mesh created by the electrical potential difference.

A system for estimating the burden of particulate levitated in a flow of gas which includes an upstream device for electrically charging the particulate, a downstream device for sensing the intensity of the field produced by the electrically charged particulate and an indicating device sensitive to an output of the downstream sensing device.

System for the measurement of the concentration particulates in a

The electrostatic conveyor consists of a duct having an inlet and an outlet, and apparatus for generating travelling, curvilinear, AC fields along the length of the duct. Charged particles, of conductive or non-conductive materials, under electrostatic forces, are exposed to unidirectional, centrifugal forces so that they are moved along the duct from the inlet to the outlet.

Continuous electrostatic conveyor for small particles

Spraying apparatus comprising a shroud in the form of a tube flared at one end and made of electrical insulating material, said shroud adapted for connection to an air supply such that in operation a high velocity air stream issues from the flared end of the shroud, at least one air shear nozzle mounted inside the shroud adjacent the flared end, a tube adapted for connection to a liquid spray source for supplying the nozzle such that in operation the liquid is atomized by the high velocity air flow and the expansion of compressed air from the supply passing over the nozzle, means for maintaining the liquid in the nozzle at ground electrical potential, a high voltage metal electrode positioned inside the flared end of the shroud in spaced relation to the nozzle, and means for supplying high voltage to the electrode such that in operation the electrode carries a high voltage positive or negative potential effective to charge by induction liquid particles or droplets issuing from the said nozzle.

Spraying apparatus

An atomized cloud of droplets having an electric charge is generated wherein different discrete parts of the cloud are formed from different liquids. The discrete part of the cloud which has an active ingredient, such as a chemical insecticide or herbicide, is contained such as by enveloping it or directing it in a particular direction by a further discrete part of the cloud that includes an inert liquid such as water. The spraying apparatus comprises a plurality of nozzles positioned in a high velocity air stream to disperse liquid and generate an atomized cloud of the liquid. The nozzles are grouped into at least two sets, each set being arranged and positioned to generate a discrete part of the cloud. An electric charge is placed on the droplets as they are emitted. Each set of nozzles further include a liquid reservoir connected to the nozzles. Each reservoir is to contain a different liquid whether it be an inert liquid or different concentrations of an active liquid.

Multi-liquid electrostatic spraying apparatus

An isolator for electrically isolating an electrostatically charged, electrically conductive coating material supply line from a grounded source of conductive coating material while continuously transferring coating material from the source to the supply line. The isolator includes a receptacle for a charged coating material reservoir and an insulative housing surrounding the charged coating material receptacle. The coating material in the receptacle is fed through an outlet to the supply line for an electrostatic coating device, which is electrostatically charged. Due to the conductive nature of the coating material, the electrostatic potential at the coating device is coupled through the coating material, and the reservoir of coating material in the receptacle is likewise electrostatically charged. The coating material from the grounded coating material source is coupled to a grounded nozzle assembly in a housing which is positioned above the charged coating material receptacle. The grounded coating material nozzle assembly includes a nozzle in a bottom portion thereof, and the coating material in the grounded nozzle assembly is mechanically vibrated to produce a pulsed jet droplet flow of electrostatic coating material from the nozzle into the charged coating material receptacle. A grounded metallic shield is mounted in the housing between the two coating material receptacles to substantially electrically shield the grounded nozzle assembly from electrical potentials below the shield, including the electrical potential of the charged coating material reservoir. The shield is apertured to permit the passage of the pulsed jet droplet flow of coating material.

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London, Canada

Ion I Inculet