University of Kentucky Research Foundation

John L Schaefer

John M Stencel

Heng Ban

James Kyle Neathery

Dennis Finseth

Tianxiang Li

An electrostatic separation apparatus or system is provided for separating a particle mixture into two constituent species. The system includes a distributor for differentially tribocharging the particle species forming the mixture and supplying the charged mixture to a plurality of electrostatic separation cells. Each cell includes at least one separator having an inlet, a separation chamber having an electric field zone for drawing selected charged particles from the particle mixture, a collector, and a transition outlet. The length of the electric field zone is selectively adjustable for varying the charged particle drawing action. A curtain gas flow introduced into the separation chamber carries the selected charged particles drawn from the particle mixture in the electric field zone to the collector. Flow vanes or straighteners are provided for both the particle mixture flow and the curtain gas flow to reduce turbulence in the separation chamber and improve separation efficiency. The collector includes a discharge outlet for discharging the selected charged particles to a first collection bin. The transition outlet receives the remaining particle flow and delivers it to a second collection bin for recovery or to a second separator to collect any remaining selected charged particles. The transition outlet reforms the flow to create turbulence to further tribocharge the particles prior to entering the second separator. A related method of particle separation is also disclosed.

Electrostatic particle separation system, apparatus, and related method

An electrostatic separation apparatus includes of a plurality of separators is provided for separating a particle mixture into two constituent species. Each separator includes one and preferably a plurality of modular separation stages. Each stage of the separator includes a pair of separation subchambers each having an electric field zone for drawing selected charged particles from the particle mixture. A curtain gas flow is provided for each subchamber to entrain and carry the selected charged particles drawn from the particle mixture in the electric field zone to a collector associated with each subchamber for recovery. The inlets for the particle mixture and curtain gas flows are adapted to straighten and smooth the respective flows to reduce turbulence in the separation subchambers and improve separation efficiency. The particle flow remaining after the first separation stage passes through an outlet to a second stage, a recycle line, or if further separation is deemed unnecessary, to a collection device for recovery. The apparatus may include a plurality of single or multistage separators arranged in parallel such that simultaneous operation is possible. Further, the apparatus may be included as part of an overall separation system.

Particle separation system using parallel multistage electrostatic separators

A triboelectrostatic separation apparatus includes a mixing chamber having opposed first and second charging ports, a separator having a separation chamber, first and second electrodes, and a variable voltage source for applying respective positive and negative voltage potentials to the electrodes. First and second particle streams are delivered through the first and second charging ports resulting in the impingement of the particle streams upon each other within the mixing chamber, thus enhancing the electrostatic charging of the particles contained within the particle streams. The apparatus may also include a pre-separator having a pre-separation chamber, a charged particle collection chamber and a plurality of feed passageways providing fluid communication between the pre-separation and the charged particle collection chambers. As a result of imparting electrical charges upon the particles, an electric field exists within the pre-separator allowing certain particles to be repelled/drawn through the passageways into the charged particle collection chamber. A method for separating electrostatically charged particles is also described.

Triboelectric separator with mixing chamber and pre-separator

A triboelectrostatic separation apparatus includes a separator with an inlet, a separation chamber, first and second electrodes, a variable voltage source for applying respective positive and negative voltage potentials to the electrodes, a pair of separated particle outlets and a curtain gas flow generation system. The curtain gas flow generation system includes a source of curtain gas at positive pressure, a metering valve for matching curtain gas flow velocity to particle flow velocity and flow straighteners for eliminating eddy currents. A method for separating electrostatically charged particles is also described.

Apparatus and method for triboelectrostatic separation

A method for separating two species of particles present in raw feedstock includes electrically charging at least one of the species of particles being separated. Next is the subjecting of the particles to both centrifugal and electrostatic forces. This is done in a manner so as to provide an additive effect and thereby achieve enhanced separation of the two particle species. An apparatus for processing the raw feedstock in accordance with the method is also disclosed.

Growing community of inventors

Lexington, KY, United States of America

John L Schaefer