JP2010029800A - Electrostatic separation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic separation device capable of improving separation precision. <P>SOLUTION: The electrostatic separation device comprises: a drum electrode 4 which is grounded, has a surface cylindrically formed and is rotated; and first and second ion generation means 6, 7 which are arranged on two places, on the upper positions of the drum electrode 4 and along the rotation direction (b) and can generate corona ions K, wherein the first ion generation means 6 arranged on the upstream side of the rotation direction (b) is constituted with a plurality of first needle electrodes 23 arranged at prescribed intervals in parallel to the rotation shaft center (a) of the drum electrode 4, the disposition direction of a second needle electrode 26 in the ion generation means 7 is set at an arbitrary angle between a tangent and a normal on a surface position of the drum electrode 4 corresponding to the second needle electrode 26 and, further, an inactive gas is supplied such that the corona ions K move along the rotation direction (b) of the drum electrode 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrostatic sorting apparatus that sorts a conductive substance such as a metal piece and an insulating substance such as a plastic piece.

  FIG. 5 shows a conventional sorting device that sorts metals, which are conductive materials (hereinafter referred to as conductive materials), and plastics, which are insulating materials (hereinafter referred to as insulating materials), using electric force. There is something like this.

  This sorter includes a constant-quantity feed unit 53 for an object to be sorted, which includes a hopper 51 and a material feed tray 52, and a surface formed in a cylindrical shape and a predetermined direction (indicated by an arrow b) around a horizontal axis a. A metal drum electrode 54 to be rotated, and a first needle-like electrode 56 and a second needle-like electrode 57 which are disposed at a predetermined distance from the drum electrode 54 obliquely upward on the downward rotation direction side of the drum electrode 54; A plate-like electrode 58 which is arranged downstream of the rotation direction and is provided at a predetermined distance from the drum electrode 54 and forms a sorting electrostatic field, and the first needle-like electrode 56 and the second needle-like electrode 57. A power supply device 59 for applying a high voltage between the plate electrode 58 and the drum electrode 54, and a cover having a first recovery chamber 61 and a second recovery chamber 62 disposed below the drum electrode 54. Selection Consisted container 63 (e.g., see Patent Document 1).

  In the above configuration, the drum electrode 54 rotated in the predetermined direction a is grounded and used as an anode, and both needle-like electrodes 56 and 57 are used as cathodes to discharge corona discharge of gas in an unequal electric field by electron impact ionization. In the state where negative corona ions are generated and irradiated to the drum electrode 54 side and an electrostatic field for separation is formed between the plate electrode 58 and the drum electrode 54 as a cathode, the object to be sorted is a conductive substance. A mixture of a certain metal piece and an insulating plastic piece is supplied from the hopper 51 onto the drum electrode 54 via the material supply tray 52. Then, the mixture is moved downstream in accordance with the rotation of the drum electrode 54, and when negative corona ions are irradiated to the metal piece and the plastic piece from the both needle-like electrodes 56 and 57, respectively, The negative charge applied is brought into contact with the drum electrode 54 to be neutralized with the positive charge of the drum electrode 54, and the positive charge is further applied from the drum electrode 54. By this action, the metal piece repels and falls with respect to the drum electrode 54. On the other hand, the plastic piece is adsorbed to the drum electrode 54 by the negative charge given by the corona ions.

  Furthermore, in the electrostatic field for separation, the metal piece having a positive charge is attracted to the plate-like electrode 58 side which is a cathode, while the plastic piece having a negative charge is acted on by an electrostatic force to act as a drum electrode. 54 is adsorbed.

As a result, the mixture was separated into a metal piece and a plastic piece and collected in the respective collection chambers 61 and 62 of the collection container 63 disposed below the drum electrode 54.
JP 2002-126777 A

  In the above configuration, in order to maintain high separation accuracy for the crushed conductor and insulator, the insulator is securely adsorbed to the grounded drum electrode, and the conductor is subjected to centrifugal force of the drum electrode. It is important to adjust the fall trajectory.

  By the way, if the size of the crushed pieces is uniform to some extent, sufficient separation accuracy can be obtained. Usually, however, crushed pieces of various sizes are mixed, and in particular, depending on the size of the conductive material, the behavior due to electrostatic force. Changes significantly.

  In particular, for thin conductors such as electric wires, when corona ions from a needle electrode are exposed, the charge immediately escapes to the grounded drum electrode, and at the next moment, the reverse charge is injected from the drum electrode. The phenomenon of rebounding occurs (as if a thin conductive material is attracted to the needle electrode side).

  When such a phenomenon occurs, when the distance between the needle electrode and the drum electrode is short, the recoiled conductive material collides with the needle electrode, or alternately reciprocates between the electrodes. Therefore, there arises a problem that the separation accuracy is lowered.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electrostatic sorting device that can improve the separation accuracy.

In order to solve the above-mentioned problems, an electrostatic sorting apparatus according to claim 1 of the present invention includes a drum electrode that is grounded and has a cylindrical surface and is rotatable about a horizontal axis in a predetermined direction. A plurality of ion generating means that are disposed at a plurality of locations above the drum electrode and along the rotation direction, and a negative voltage is applied to generate corona ions,
Among the plurality of ion generating means, a plurality of needle-like electrodes arranged at predetermined intervals in parallel with the rotation axis of the drum electrode, or tips The portion is formed in a pointed shape and is configured by a plate-like electrode arranged in parallel with the rotation axis of the drum electrode,
The installation direction of the electrode in the upstream ion generating means is set to an arbitrary angle between the tangent and the normal at the surface position of the drum electrode corresponding to the electrode.

  Further, in the electrostatic sorting apparatus according to claim 2, the corona ions generated by the electrodes of the upstream ion generating means in the electrostatic sorting apparatus according to claim 1 are moved along the rotation direction of the drum electrode. In addition, an inert gas is blown out.

  Furthermore, in the electrostatic sorting apparatus according to claim 3, the corona ions generated by the electrodes of the upstream ion generating means in the electrostatic sorting apparatus according to claim 1 or 2 are in a direction opposite to the rotation direction of the drum electrode. It is equipped with an ion backflow preventer that prevents it from moving.

  According to the above configuration, of the ion generating means arranged at a plurality of locations along the rotation direction, the ion generating means arranged on the upstream side is a needle-like electrode or a plate-like electrode having a pointed tip. And the setting direction of the electrode is set to an arbitrary angle between the tangent and the normal line at the surface position of the drum electrode corresponding to the electrode. The irradiated corona ions move along the rotation direction of the drum electrode (more precisely, the downstream side of the rotation direction). For example, even when the conductive material is a thin wire and tries to recoil from the drum electrode. Many of them move in the direction of rotation, and can be prevented from colliding with other needle-shaped electrodes arranged along the drum electrode, so that the conductive material is prevented from being mixed into the insulating material as much as possible. It is possible Kusuru, it is possible to improve the separation accuracy.

  In addition, since the inert gas is blown out along the rotation direction of the drum electrode, the conductive material recoiled to the drum electrode can be guided in the rotation direction of the drum electrode, so that the separation accuracy can be further improved. Can be planned.

  Further, since the corona ion inflow prevention device is provided, it is possible to prevent the conductive material that has rebounded from the drum electrode from returning to the material supply means side, and therefore, further improve the separation accuracy. be able to.

[Embodiment]
Hereinafter, an electrostatic sorting apparatus according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 to 3, this sorting apparatus is crushed conductive material [hereinafter also referred to as a conductive material, for example, a metal thin wire such as a metal piece or electric wire] B and a non-conductive material, that is, an insulating material. Storage hopper 1 for storing a material to be sorted (hereinafter also referred to as a mixture) A and a mixture from the storage hopper 1 A quantitative supply device 3 constituted by a material supply means (for example, a material supply tray or a material supply plate, specifically, a vibration type supply machine is used) 2 capable of quantitatively supplying A by vibration; A metal drum electrode 4 which is grounded (grounded) and whose surface is formed in a cylindrical shape and is rotated around a horizontal axis a in a predetermined direction (also a rotation direction, indicated by an arrow b), and the drum electrode 4 downwards It is provided at a position diagonally above the rotation start position (A) and at a predetermined distance from the drum electrode 4 and in the rotation direction b from the upstream side to the downstream side, that is, a low position slightly downstream from the highest position (A). First ion generating means (upstream ion generating means) 6 and second ion generating means 7 that are sequentially arranged along the line to generate corona ions (also referred to as ion wind), and the downstream side of the second ion generating means 7 And a plate-like electrode (for example, a plate electrode is used) 8 for forming an electrostatic field for sorting arranged at a predetermined distance from the drum electrode 4, the first ion generating means 6 and the second ion A power supply device 9 for applying a high voltage between the generating means 7 and the plate electrode 8 and the drum electrode 4, and a partition wall disposed below the drum electrode 4 and provided in the center And a first collection chamber 12 and the second recovery chamber 13 is formed an insulator C and collecting container 14 which the conductive material B by one. Reference numeral 15 denotes a scraper for the insulator C disposed at the downstream side in the rotation direction of the drum electrode 4 in the collection container 14.

  The first ion generating means 6 is a manifold in which a plurality of holes 22 in a predetermined direction are formed at predetermined intervals along the rotation axis a while being arranged in parallel with the rotation axis a of the drum electrode 4. 21 and a first needle electrode (an example of a needle-like electrode, which may be a wire electrode) 23 arranged at the center in each hole portion 22 of the manifold 21 so as to have an annular gap. The installation direction of the manifold 21, that is, the installation direction of the hole 22, is tangent to the drum electrode 4 (more precisely, the tangent at the surface position of the drum electrode facing the first needle electrode) and the tangent. An arbitrary angle θ between the inclined line d of 60 degrees is set. The angle θ may be an angle up to a normal line (not including 90 degrees) orthogonal to the tangent line (in the angle range, 0 <θ <90). In other words, the ion irradiation direction may be directed to the downstream side in the rotation direction of the drum electrode 4 as much as possible. Moreover, as preferable angle (theta), it is the range of 30-60 degrees.

  Further, the manifold 21 in the first ion generating means 6 is configured such that the inert gas G is blown out from the hole 22 thereof. Specifically, an inert gas supply device (not shown) is provided. It is equipped.

  That is, the corona ions K generated by the first ion generating means 6 are irradiated in the direction in which the mixture A, which is an object to be sorted, is carried by the rotation of the drum electrode 4 by the inert gas G blown out from the hole 22. Will be.

  Further, an ion backflow preventer 24 for preventing corona ions K generated by the first needle electrode 23 from flowing into the material supply means 2 side is provided on the lower surface of the manifold 21. For example, the ion backflow prevention device 24 includes a horizontal mounting plate portion 24 a and a downward inclined plate portion 24 b so as to close a gap between the lower surface of the manifold 21 and the upper surface of the drum electrode 1.

  On the other hand, a plurality of the second ion generation means 7 are arranged at predetermined intervals along the rotation axis a along the support member 25 arranged in parallel with the rotation axis a of the drum electrode 4. And the second needle electrode 26.

  In the above configuration, the drum electrode 4 rotated in the predetermined direction b is grounded and used as an anode, and the first needle electrode 23 and the second needle electrode 26 are used as cathodes, and a high voltage is applied by the power supply device 9 to obtain an unequal electric field. The gas inside is subjected to corona discharge by electron collision separation action to generate negative corona ions K and irradiate the drum electrode 4. In addition, an electrostatic field for sorting is formed between the plate electrode 8 as a cathode and the drum electrode 4 by the power supply device 9.

  In this state, for example, a material in which a mixture A of a copper wire (conductive material) B and a plastic piece (insulator) C formed by pulverizing a plastic-coated waste wire vibrates in the vertical and longitudinal directions from the storage hopper 1 It is discharged onto the supply means 2 and quantitatively supplied (dropped) to the surface of the drum electrode 4.

  The mixture A dropped on the surface of the drum electrode 4 is irradiated with corona ions K due to corona discharge from the first needle electrode 23 and the second needle electrode 26 while being moved according to the rotation of the drum electrode 4, and negative charge is generated. Given.

  Of this mixture A, the plastic piece C is adsorbed to the drum electrode 4 by the negative charges given by the corona ions K generated by the corona discharge from the needle electrodes 6 and 7, and then the plate electrode 8 and the drum electrode 4. The electrostatic force acts on the plastic piece C having a negative charge and is adsorbed to the drum electrode 4 and moves with the rotation of the drum electrode 4, and approaches the drum electrode 4. It falls along a fall trajectory or is scraped off by the scraping tool 15 and collected in the first collection chamber 11.

  On the other hand, in the mixture A, the copper wire B is neutralized when the negative charge given by the corona ion K comes into contact with the drum electrode 4 and is given a positive charge from the drum electrode 4. Repels against the drum electrode 4, and further, in the electrostatic field for separation, it is attracted to the plate-like electrode 8 side that is the cathode, and jumps in a direction away from the drum electrode 4 with a fall trajectory. It is collected in the collection chamber 12.

  By the way, at the time of sorting, the direction of the inert gas G blown out from the hole 22 in which the first needle electrode 23 is disposed is the rotation direction a of the drum electrode 4 and the direction inclined with respect to the tangent line. In addition, since the mixture A is guided in the rotation direction a, the recoil phenomenon that easily appears in a thin conductive material such as an electric wire is suppressed, the return to the material supply means 2 side is eliminated, and the ion backflow prevention device 24 is provided. Thus, there is no more return (back flow) to the material supply means 2 side.

  Here, the result of comparing the separation performance of the electrostatic sorting apparatus according to the present embodiment (referred to as the apparatus of the present invention) and the conventional electrostatic sorting apparatus (referred to as the conventional apparatus) will be described based on the graph of FIG.

The graph shown in FIG. 3 shows a case where the present invention is applied to a mixture crushed under 10 mm, and shows the relationship between the dropping position of the substance and the recovery rate.
The configuration of the apparatus that collected the data of this graph will be described. The tip position of the first needle electrode 23 is rotated from the uppermost position of the drum electrode 4 (vertical axis passing through the center of the drum electrode) in the rotation direction (clockwise in FIG. 1). ) At a position of 10 degrees (corresponding to a position where the mixture naturally moves from the surface of the drum electrode when no voltage is applied) and the inclination angle θ of the first needle electrode 23 is set to 40 degrees. The tip position of the two-needle electrode 26 is set to a position of 40 degrees in the rotation direction from the uppermost position of the drum electrode 4. The distance between the surface of the drum electrode 4 and both the needle electrodes 23 and 26 was 60 mm, and the voltage applied to both the electrodes 23 and 26 was 30 kV.

  From this graph, according to the conventional apparatus, the insulator falls within the range of about +10 cm from the end position (0 cm) of the drum electrode, which is indicated by the needle electrode and the plate electrode (particularly the plate electrode). It is because it has collided with. On the other hand, in the device of the present invention, the amount of fall of the insulator within the same range (0 to +10 cm) is reduced, and the amount of fall of the conductive material in the range exceeding +10 cm, that is, the recovered amount is increased. Yes. That is, it can be seen that the separation accuracy of the device of the present invention is improved compared to the conventional device.

  According to said structure, among the ion generating means arrange | positioned in multiple places along a rotation direction, the 1st ion generating means arrange | positioned upstream is a needle electrode or a wire electrode (collectively called a needle electrode). Since the installation direction of the needle electrode is set to an arbitrary angle between the tangent line at the surface position of the drum electrode corresponding to the electrode and an inclined line of 60 degrees with respect to the tangent line, The corona ions irradiated by the ion generating means disposed on the side are irradiated along the rotation direction of the drum electrode (more precisely, the downstream side of the rotation direction). Even when an attempt is made to recoil from the electrode, many of them will move in the rotational direction, and other needle electrodes arranged along the drum electrode, that is, the second needle electrode of the second ion generating means. Can prevent the collision with the plate-shaped electrode, hence the conductive material can be minimized from being mixed into the insulating material, it is possible to improve the separation accuracy.

  In addition, since the inert gas is blown out along the rotation direction of the drum electrode, the conductive material that has rebounded from the drum electrode can be guided in the rotation direction of the drum electrode, thereby further improving the separation accuracy. be able to.

  Further, since the corona ion backflow prevention device is provided, it is possible to prevent the conductive material that has rebounded from the drum electrode from returning to the material supply means side, and therefore, the separation accuracy can be further improved. it can.

Here, a supplementary explanation of the above-described actions and effects will be given.
For example, as a method for improving the separation accuracy, it is conceivable to move the partition wall to the inside of the drum electrode closer to the center, and collect only the material adsorbed on the drum electrode. Since there are various types of substances, it is difficult to improve the separation accuracy by moving the position of the partition wall. In other words, since it is easier to eliminate the behavior of the charged conductive material (collision with the corona generating electrode and repeated recoil between the electrodes), the electrode installation direction is taken into account, and the corona is inactivated by the inert gas. The ion blowing direction is adjusted.

  Further, as described above, the first needle electrode is disposed at a position where the mixture starts to be supplied to the drum electrode, specifically, near the material supply means or slightly ahead of the position where the mixture slides down from the drum electrode. Preferably, when the mixture is supplied to the drum electrode in the vicinity of the material supply means, the mixture from the material supply means is pushed back by the corona ions to supply a single layer of the mixture (supplied so that the mixture does not overlap vertically) Therefore, the mixture is supplied to the drum electrode as close to the material supply means as possible, and an inert gas is used to prevent the mixture from being pushed back. The corona ions are blown out downstream in the rotational direction.

  By the way, in the said embodiment, although the 1st ion generation means 6 was comprised by the manifold 21 which has the hole 22, and the 1st needle electrode 23 penetrated by the hole 22 of this manifold 21, it is a drum electrode, for example. 4 may be constituted by a plurality of cylindrical members arranged at predetermined intervals along the rotation axis a, and needle electrodes or wire electrodes arranged at the centers of these cylindrical members. As shown, the first ion generating means 6 ′ is arranged in a manifold 31 formed with a groove (also referred to as a slit) 32 along the rotation axis a of the drum electrode 4 and in the groove 32 of the manifold 31. You may use what was comprised with the plate-shaped electrode 33 formed so that a front-end | tip part might be sharp.

It is sectional drawing which shows schematic structure of the electrostatic selection apparatus which concerns on embodiment of this invention. It is a perspective view which shows the 1st needle electrode part in the electrostatic sorting device. It is a graph explaining the sorting collection state in the electrostatic sorting device. It is a perspective view which shows the modification of the 1st ion generation means in the electrostatic sorting device. It is sectional drawing which shows schematic structure of the electrostatic sorting apparatus of a prior art example.

Explanation of symbols

A Material to be selected B Conductive substance C Insulating substance 1 Storage hopper 2 Material supply means 3 Constant supply device 4 Drum electrode 6 First ion generation means 7 Second ion generation means 8 Plate electrode 21 Manifold 22 Hole 23 First One needle electrode 24 Ion backflow preventer 26 Second needle electrode 31 Manifold 32 Groove 33 Plate electrode

Claims (3)

A drum electrode that is grounded and has a cylindrical surface and is rotatably provided in a predetermined direction around a horizontal axis, and is disposed at a plurality of locations above the drum electrode and along the rotation direction. A plurality of ion generating means for generating corona ions when a negative voltage is applied;
Among the plurality of ion generating means, a plurality of needle-like electrodes arranged at predetermined intervals in parallel with the rotation axis of the drum electrode, or tips The portion is formed in a pointed shape and is configured by a plate-like electrode arranged in parallel with the rotation axis of the drum electrode,
An electrostatic sorting apparatus characterized in that the installation direction of the electrode in the upstream ion generating means is set to an arbitrary angle between a tangent and a normal at the surface position of the drum electrode corresponding to the electrode.   2. The electrostatic apparatus according to claim 1, wherein the inert gas is blown out so that corona ions generated by the electrode of the upstream ion generating means move along the rotation direction of the drum electrode. Sorting device.   The ion backflow preventer for preventing corona ions generated by the electrode of the upstream ion generating means from moving in the direction opposite to the rotation direction of the drum electrode is provided. Electrostatic sorting device.

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