RU2351399C1 - Corona electric separator - Google Patents

Abstract

FIELD: electric equipment.

SUBSTANCE: invention concerns electric separation of commensurate particles with equal dielectric properties and size and different surface resistance. Corona separator includes loading tank, high voltage source, electric motor, corona and electroconductive earthed precipitation electrodes. Precipitation electrode is constructed in the form of conveyor belt. Corona electrode is limited, its size and positioning can be adjusted to control charge and discharge areas located in front of particle separation area.

EFFECT: enhanced efficiency of hardly separable mix separation.

1 dwg

Description

The invention relates to the electrical separation of proportional particles and can be used in the separation of a mixture of materials.

Known electrocrown separator (AS No. 484010, M. Cl. V03C 7/02, Bull. No. 34, 09/15/75), consisting of a loading hopper, a horizontal belt conveyor, a corona electrode. However, the known electro-corona separator does not allow the separation of proportionate particles with the same dielectric properties.

Known corona electrostatic separator (AS No. 1592046, IPC V03C 7/02, Bull. No. 34, 09/15/90), taken as a prototype and consisting of a hopper-feeder, a metal electrically conductive grounded precipitation electrode, a corona electrode, a classifier , a high voltage source and brushes to remove adhering particles.

On this separator, the fan for separating the components of the mixture is determined by the electrical properties of the particles. Due to the difference in dielectric constants, electrical conductivity and depolarization coefficient, particles get different charges.

The disadvantage of the prototype is that this corona electrostatic separator does not share proportional particles with the same dielectric properties.

The purpose of the technical solution is to separate particles that are identical in dielectric properties and sizes, but different in surface resistance.

To solve this goal, the separator has several design differences. The precipitation electrode instead of the drum is made in the form of a conveyor belt of electrically conductive material stretched over two grounded metal cylinders. The corona electrode is limited and configured to change sizes and locations to control the charging and discharging zones located in front of the particle separation zone, thereby creating two distinct zones that can change their sizes: the charging zone and the discharge zone located in front of the separation zone. Changing the size of the zones allows you to get the necessary time for charging and discharging, this determines the charge of the particles, which makes it possible to separate the particles by the residual charge.

The set of essential features of the presented technical solution, namely: a conductive tape, a corona electrode, made with the possibility of changing the size and location to control the duration of the charging and discharging zones, allowing to obtain a new economic effect - the separation of proportionate particles that are identical in dielectric properties and sizes, but different in surface resistance, are not known from the prior art, which allows us to conclude that the proposed invention iterations “novelty” and “inventive step”.

The corona electric separator (see drawing) consists of an electric motor 6, a loading hopper 5, a high voltage source 7, a precipitation electrode 2, a corona electrode 1 movable and resizing, which is limited by the charging zone. The corona electrode is made of two telescopic rails parallel to each other, located on a movable frame, between which thin wires are stretched. Precipitation electrode 2, made in the form of a conveyor belt of conductive material and rotating on two grounded metal cylinders, classifier 4, brushes to remove adhering particles 3.

The separator works as follows.

When a voltage is applied to the corona electrode 1, a corona discharge field arises. Particles from the hopper 5 enter the charging zone between the corona 1 and precipitation 2 electrodes, resulting in an electric charge. After leaving the charging zone, the particles fall into the discharge zone, where they are discharged. An electric charge received by a particle in a corona discharge field flows onto an electrically conductive tape.

Particles with different parameters will be charged differently in the charging zone and discharged in the discharge zone. To obtain the required difference in particle charges, it is necessary to change the duration of the charging and discharging zones. The corona electrode is made of two telescopic rails parallel to each other, located on a movable frame, between which thin wires are stretched. When changing the charging zone, the guides extend or retract; when changing the discharge zone, the movable frame moves on the slide. Other corona electrode designs may be proposed to change charge and discharge zones. The basic condition should be that the corona electrode must be movable and be able to change its size.

The discharge rate depends on the contact resistance “particle-electrode”, is determined by the surface resistance of the particle and the electrical conductivity of the conveyor belt. Particles with lower surface resistance discharge faster than with higher resistance.

When leaving the discharge zone, the particles fall into the separation zone, where they are affected by the sum of forces, which determines the separation angle of the particle from the electrode. Three forces act on a particle in this zone: the force of interaction of a charged particle with the plane of the tape; gravity and centripetal force. The first force presses the particle against the tape, it depends on the size of the particle’s charge, the centrifugal force pushes it away, and gravity in the upper half cylinder presses it against the tape, in the lower - it tears it off.

Depending on the total effect of the forces, the distribution of particles forms a fan. Particles with low contact resistance have time to discharge to the separation zone and are discarded by inertia from the surface of the tape. Particles with large contact resistance carry a charge on themselves, thereby being pressed against it by electric forces.

The residual charge of the particles determines the angle of separation of the particles from the rotating electrode. The lower the electrical resistance of the particles, the faster they come off the surface of the rotating electrode. Depending on the residual charge, the particles are divided into classes in the receiving device after separation from the conveyor belt.

The corona electric separator allows the separation of proportionate particles with the same dielectric properties due to differences in surface resistance and thereby separate difficultly separated mixtures.

Claims (1)

A corona electric separator consisting of a loading hopper, a high voltage source, an electric motor, a corona and electrically conductive grounded sedimentation electrodes, characterized in that the design of the precipitation electrode is made in the form of a conveyor belt, the corona electrode is limited and configured to change sizes and locations to control charging zones and discharges located in front of the particle separation zone.