Abstract: 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.

Abstract: A water treatment apparatus is provided in which the ozone generation and the water treatment may take place simultaneously. The ozone is generated from a continuous supply of air and/or oxygen at the surface of a running water by means of a high voltage electrode placed in the air or in oxygen at some distance above the water surface. The strong electric field between the high voltage electrode and the surface of the electrically grounded water stream generates a multitude of small Taylor cones at the surface of the water. Each Taylor cone goes into corona and in the process it generates the ozone. As the ozone is generated at the water surface, a substantial amount of ozone is immediately dissolved in water and the ozone that diffuses in the air continues to be in contact with the water surface. The undissolved ozone may be percolated through the same water for an additional primary or secondary ozonation.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method and apparatus for separating liquid for material of differing permativity is disclosed. The method involves the application of an AC voltage to a material to create an a non-uniform electric field of the same frequency as the applied AC voltage which decreases in strength the further the radial distance from the point of application to induce flow of the liquid in the material. Collection means are located in the path of induced flow to collect the liquid. The apparatus of the invention consists of a means of generating an AC voltage, a terminal in contact with material and connected to the means of generating the voltage so as to receive the material and impart a non-uniform electric field to the material. Means for collecting the liquid that collects at a region in which the liquid is concentrated is also provided.

Abstract: An electret comprising an inherently charged material is provided. The material comprises phyllosilicate minerals and has external neutralizing ions removed therefrom or external ions added thereto. The electret is manufactured by either removing external ions from or adding external ions to a surface thereof. In a preferred embodiment, the electret is fabricated by placing the material between a pair of electrodes and immersing the material and electrodes in high-voltage insulating medium. A dc potential is then applied across the electrodes to create an electric field across the material. The duration of application of the dc potential is sufficient to provide a large surface charge on the material. The material is then separated from the electrodes while it is still immersed in the insulating medium. The separated material is then removed from the medium to obtain a substantially permanently charged electret.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An electrostatic high voltage isolation system with internal charge generation in which conductive coating material to be sprayed is electrostatically charged by charging discrete droplets of coating material transferred from a coating material source to a supply of coating material for a spray gun. The source of coating material includes an electrically grounded reservoir of coating material having a nozzle aperture in a bottom portion thereof, and the coating material in the reservoir is mechanically vibrated to produce a pulsed jet droplet flow of coating material from the nozzle into a supply container for the spray gun. A high voltage electrode at the location of droplet formation induces an electrostatic charge on the droplets in order to electrostatically charge the coating material transferred to the gun supply container for use by the gun for electrostatic coating.

Abstract: Particles having different properties (e.g. particulate fly ash and carbon) are separated by driving the particles by means of a vibratory feeder (12) forwards along a horizontal electrode plate (1) above which is mounted a second electrode (2) having at least one plate (4) mounted at an acute angle (.alpha.) to the horizontal. Preferably, two plates (4) each extend sideways from a central block (3) of dielectric material. An alternating electric field is generated between the electrodes (1, 2) by a high voltage AC power source (14). The potential across each plate (4) varies (in particular, decreases) in the lateral direction, the variation being continuous or stepwise. The field lines (16) from each plate (4) curve to the side and impart centrifugal forces to particles charged by friction or conductive induction, which forces separate lighter, more heavily charged particles from the others. The separated particles are collected in bins (13) arranged around the lower electrode (1).

Abstract: Particles having different properties (e.g. particulate fly ash and carbon) are separated by moving the particles forwards along a horizontal electrode plate (1) above which is mounted a second electrode (2) having two plates (4) each extending sideways from a central block (3) of dielectric material at an acute angle (.alpha.) to the horizontal. An alternating electric field is generated between the electrodes (1, 2) by a high voltage AC power source (14). The field lines (16) from each plate curve to the side and impart centrifugal forces to particles charged by friction or conductive induction, which forces separate lighter, more highly charged particles from the others. The separated particles are collected in bins (13) arranged around the lower electrode (1), which electrode is mounted on a vibratory transducer (12).

Abstract: The electrostatic nozzle may be used to spray one or more charged clouds in different areas of an enclosed room to allow different materials to be deposited on different sections of the surfaces. The nozzle includes a conduit through which air passes over one or more airfoils to entrain a liquid across the surface. A charged electrode, facing the surface, inductively charges the liquid on the surface. The liquid is atomized at the trailing edge of the airfoil by a cross-current created by an air deflector near the trailing edge of the airfoil.

Abstract: A nozzle for spraying apparatus to distribute crop treatment liquid. The nozzle is of general ogee shape with a base and an upper wall spaced from the base and connected to it by side walls. The upper wall extends from the apex of the base partially along the base to terminate in a trailing edge. The nozzle is placed in a high velocity air stream and liquid introduced between the base and upper wall. The high velocity airstream atomizes the liquid and distributes it in the surrounding environment. The nozzle is particularly useful in electrostatic spraying apparatus and may be made of plastics material to inhibit induction of electrostatic charge on the nozzle.