JP2004136207A - Frictional charging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a frictional charging apparatus whereby chargeable plastic particles as an objective to be separated can be continuously and efficiently subjected to frictional charging. <P>SOLUTION: A plastic particle mixture containing plastic particles as the objective to be separated and friction assisting particles are agitated in the agitation container 31 of a mixer 3 to frictionally charge the above particles. The friction assisting particles are separated from the plastic particle mixture by means of a classifier 4. The friction assisting particles reduced in a charge quantity by spontaneous discharging or still more reduced in a charge quantity optionally by static eliminator 64 are fed into the container 31 and are repeatedly used. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a frictional charging device, and more particularly to a frictional charging device that charges a mixture of a plurality of types of plastic particles and electrostatically sorts the mixture.
[0002]
[Prior art]
Recent trends in the reuse of plastics have necessitated the development or improvement of triboelectric charging devices including electrostatic sorting devices. As such a frictional charging device, for example, a discharge port formed at an end of a stirring vessel is provided with a plurality of discharge wire sections arranged in parallel at a predetermined interval along a cross section of the stirring vessel, Any one of the above plastics so that the proportion of the specific kind of plastic piece to be sorted and the plastic piece having the opposite polarity to this particular kind of plastic piece in the electrified train of the kind plastic pieces are equal. Are placed in a stirring vessel as a friction auxiliary material, the friction auxiliary material particles are made larger than the plastic piece, and the spacing between the wires of each discharge section is set larger than the plastic piece and smaller than the friction auxiliary material. Is conventionally known (see Patent Document 1).
[0003]
Further, as another example of a frictional charging device, a frictional charging device for stirring a plastic piece obtained by mixing a plurality of types of pulverized particles and frictionally charging the plastic piece to the polarity and charge amount of each plastic piece, and a drop port portion of the frictional charging device Below, an electrostatic separation unit for separating frictionally charged plastic pieces, and a separation container for separately collecting the plastic pieces separated by this electrostatic separation unit for each polarity and electrode When feeding a plurality of types of plastic pieces into the triboelectric charging device, if the amount of the specific plastic piece is small, the specific plastic piece or the plastic piece located in the middle of the charging sequence of the same type or mixed plastic pieces may be removed. A predetermined amount was added as a frictional charging auxiliary material, and a net was attached to the dropping port of the frictional charging device to leave a plastic piece to be added. Also known conventionally (see Patent Document 2).
[0004]
[Patent Document 1]
JP 2000-140701 A (Summary Solution, FIG. 1)
[Patent Document 2]
Japanese Patent Application Laid-Open No. 2000-126649 (Abstract solution means, FIG. 1)
[0005]
By the way, since the amount of electricity of positive charge and negative charge generated by friction is always equal, for example, when the plastic piece is positively charged, the friction auxiliary material and the stirring container are negatively charged. Therefore, when a plastic piece is frictionally charged by the friction charging device disclosed in Patent Documents 1 and 2, etc., if the charged plastic piece is continuously supplied to the stirring vessel, the charging of the friction auxiliary material and the stirring vessel becomes saturated. As a result, there is a problem that the subsequent charging of the plastic piece to be charged is insufficient or the charging is not performed. In addition, when a plastic piece is continuously supplied to the frictional charging device and frictionally charged, the amount of charge of the friction auxiliary material and the stirring container gradually increases. There is a problem that the frictional charging efficiency of the charged plastic piece is reduced by such a phenomenon.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a frictional charging device capable of continuously and efficiently frictionally charging plastic particles to be sorted in consideration of the problems in the prior art. .
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a frictional charging device according to the first aspect of the present invention, wherein the plastic particle mixture containing the plastic particles to be sorted and the plastic particles to be sorted have opposite charging polarities and the plastic particle mixture has a particle size that can be classified. A stirrer for stirring the particles, a classifier for classifying the mixture stirred by the stirrer into the plastic particle mixture and the friction assisting particles, and an electrostatic separation for selecting the plastic particle mixture classified by the classifier. And a first supply device for supplying the friction assisting particles classified by the classification device to the stirring device.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described, but if the same part as the part shown in the figure in the earlier order of the description is shown in the subsequent figure, the description will be omitted by attaching the same reference numeral to the subsequent figure, Also, some of the reference numerals may be omitted.
[0009]
Embodiment 1 FIG.
FIGS. 1 and 2 illustrate a first embodiment of the frictional charging device of the present invention. FIG. 1 is a schematic explanatory view including a partial cross-sectional view of the first embodiment, and FIG. 1 is a partially enlarged perspective view of FIG. 1 and 2, the frictional charging device S includes a charging hopper 1, a dust collecting device 2, a stirring device 3, a classifying device 4, an electrostatic sorting device 5, and a first supply device 6. In FIG. 1 and other drawings, a black arrow indicates a moving direction of particles, and a white arrow indicates a flowing direction of an air flow.
[0010]
The stirring device 3 includes a cylindrical stirring container 31, a motor 32, a belt 33, and an angle adjusting device 34. The motor 32 is supported by a suitable support (not shown), and drives the stirring container 31 via the belt 33. It can be rotated around its axis 311. On the inner surface of the stirring vessel 31, four scraping blades 312 extending in the longitudinal direction of the stirring vessel 31 are provided at equal intervals in the circumferential direction. The angle adjusting device 34 is a stirring vessel including a base 341, two members fixed to both ends of the stirring vessel 31, and a plate connected to the two members and provided in parallel with the lower surface of the stirring vessel 31. The support 342 includes the base 341 and the angle adjusting columns 343 and 344 connected to the stirring container support 342. By sliding the angle adjusting column 344 on the base 341, the stirring container 31 is moved to the base 341. Can be set and fixed at a desired angle α. The two-dot chain line in FIG. 1 shows a state where the angle adjustment support 344 is slid on the base 341 to near the left end, and the stirring vessel 31 is substantially parallel (horizontal) with the base 341.
[0011]
The dust collecting device 2 cannot pass particles (hereinafter, particles P1) constituting the plastic particle mixture (hereinafter, may be abbreviated as a particle mixture), but cannot pass through the particle mixture or the friction auxiliary particles (hereinafter, particle P2). It has a perforated cylindrical body 21 as an example of the perforated body having a plurality of small holes 211 through which dust adhering to the like can pass and communicating with the stirring vessel 31. In addition, four scraping blades 312 extending from the stirring vessel 31 are provided on the inner surface of the perforated cylindrical body 21 (see FIG. 7 described later).
[0012]
The classifying device 4 is constituted by a perforated cylinder having substantially the same diameter as the stirring vessel 31, and is rotated around the axis 311 together with the stirring vessel 31. When the frictional charging device of the present invention is operated, a particle mixture containing the plastic particles to be sorted and the particles P2 are used. As the particles P2, those having a particle size that can be classified from the particles P1 are used. In FIG. 1, it is assumed that, for example, particles having a particle size much larger than the maximum particle size of the particle mixture are used as the particles P2. For this reason, the classifier 4 allows the particles P1 to pass and the particles P2 not to pass. A plurality of large holes 41 are formed. For this reason, when the mixture of the particle mixture and the particles P2 stirred in the stirring vessel 31 passes through the classification device 4, the particles P1 pass through the large holes 41 and fall toward the electrostatic sorting device 5. , The particles P2 are discharged from the outlet 42 of the classification device 4, thus classifying the particle mixture and the particles P2.
[0013]
The electrostatic sorting device 5 is of a general counter electrode type, and includes high-voltage power supplies 51 and 52, high-voltage electrodes 53 and 54, and a separation container 55. The first supply device 6 includes a screw conveyor type transfer device 61, a recollection hopper 62, and a fixed amount supply device 63.
[0014]
Next, the operation of the frictional charging device according to the first embodiment will be described. First, the angle adjusting device 34 adjusts and sets the stirring container 31 of the stirring device 3 to a desired angle α. At that time, the perforated cylinder 21 of the dust collector 2 and the classifier 4 are also set to the same angle α. In the first embodiment and the subsequent embodiments, the dust collecting device 2 and the classifying device 4 do not necessarily need to be set to the same angle α as that of the stirring vessel 31, and can be individually adjusted and set to a desired angle. Although the structure may be used, there is an advantage that the structure and operation of the apparatus can be simplified without causing any inconvenience in many cases even if the rotation angle is the same as that of the stirring vessel 31 and the rotation speed is the same as that of the stirring vessel 31. .
[0015]
When the dust collecting device 2, the stirring device 3, and the classifying device 4 are inclined at an angle α as shown in FIG. 1, the particle mixture and the particles P2 input from the input hopper 1 are rotated at an appropriate speed while being stirred. There is an effect that the dust collection device 2 can be moved to the classification device 4 via the stirring container 31. However, if the angle α is too large, the speed of the movement will be too high, and the degree of stirring of the particles in the stirring vessel 31 will be insufficient, and if the angle α is too small, the speed of the movement will be too small. As a result, the treatment efficiency of the particle mixture to be treated decreases. Therefore, the angle α may be set to an optimum value by trial and error in accordance with the type and properties of the particle mixture to be processed.
[0016]
The angle α is set to a desired size, and the electric motor 32 is driven to rotate the dust collecting device 2, the stirring container 31, and the classifying device 4 at a desired rotation speed. And the particles P2 are charged. As the particles P2, those having a large particle diameter that has a polarity opposite to that of the plastic particles to be sorted and that can be classified from the particle mixture are used. The particle mixture and the particles P2 enter the dust collector 2 through the entrance 28 of the dust collector 2, where fine dust adhering to each of the particles P1 and P2 is removed. The particles are scraped up and agitated well by 312, and each particle is charged according to the charging sequence. Next, in the classifying device 4, the particles P1 pass through the large holes 41 and fall into the electrostatic sorting device 5, and the particles P2 are temporarily stored in the container 43, and then re-collected by the transfer device 61 from the hopper 611. It is conveyed to 62 and stored.
[0017]
In the electrostatic sorting device 5, a high voltage is applied to the high-voltage electrodes 53 and 54 by the high-voltage power supplies 51 and 52, and the particles P1 constituting the particle mixture are charged while passing between the high-voltage electrodes 53 and 54. It is separated into the chamber 551 or the chamber 552 of the separation container 55 according to the amount and the charging polarity. On the other hand, the required amount of the friction auxiliary particles P2 accommodated in the re-collection hopper 62 is measured in the quantitative supply device 63, and is input to the input hopper 1 together with the new particle mixture to be reused. The particles P2 classified by the classifying device 4 are repeatedly used because the amount of charge is reduced by natural discharge while reaching the charging hopper 1 via the transport device 61, the recollection hopper 62, and the quantitative supply device 63. There is an effect that can be
Embodiment 2 FIG.
FIG. 3 is a schematic explanatory view including a partial cross-sectional view of Embodiment 2 of the frictional charging device of the present invention. The second embodiment is different from the first embodiment in that the second embodiment has a static elimination device 64 installed near the outlet 42 of the classification device 4 as an element of the first supply device 6 of the present invention. Is the same. The particles P2 classified by the classifier 4 are positively reduced or removed by the neutralizer 64 while falling into the container 43 from the outlet 42. Accordingly, the triboelectric charging efficiency of the plastic particles to be sorted is more effectively improved than in the case of Embodiment 1 in which the charge amount of the particles P2 subjected to the neutralization treatment is reduced by natural discharge.
[0019]
Embodiment 3 FIG.
FIGS. 4 and 5 each illustrate a third embodiment of the frictional charging device of the present invention. FIG. 4 is a schematic explanatory view including a partial cross-sectional view of the frictional charging device of the present invention. Explains the charging state of the particles P1 and P2. In FIG. 5, small white circles represent uncharged particles P1, small black circles represent positively charged particles P1, small white triangles represent negatively charged particles P1, large white circles represent uncharged particles P2, and large white circles containing minus. Indicates the negatively charged particles P2.
[0020]
In the third embodiment, a space is provided between the chamber 551 and the chamber 552 in the separation container 55, and a chamber 553 for accommodating unsorted plastic particles is provided immediately below the center between the high-voltage electrodes 53 and 54. The third embodiment is different from the second embodiment in that a second supply device 7 for transporting the particles P1 accumulated in the chamber 553 is provided. The particle mixture subjected to the charging treatment in the stirring vessel 31 may include an uncharged or insufficiently charged portion, and these portions fall into the chamber 553.
[0021]
The second supply device 7 includes a transfer device 71 connected to the transfer device 61. The particles P1 accumulated in the chamber 553 are collected from the hopper 711 by the transfer device 71, and then collected again by the transfer device 61. Is transported and stored. In many cases, the particles P1 accumulated in the chamber 553 are conveyed together with the particles P2 in the conveying device 61, and are conveniently mixed with the particles P2 and preliminarily charged at this time, and are passed through the metering device 63. Is charged again into the charging hopper 1 and is charged in the stirring vessel 31 together with the new particle mixture. The second supply device 7 may directly feed the particles P1 stored in the chamber 553 into the charging hopper 1. In any case, the provision of the chamber 553 and the second supply device 7 has the effect of improving the charging efficiency of the particle mixture.
[0022]
Embodiment 4 FIG.
FIG. 6 is a schematic explanatory view including a partial cross-sectional view of Embodiment 4 of the frictional charging device of the present invention. Embodiment 4 is different from Embodiment 3 in that a heating device 65 is provided in the vicinity of the fixed amount supply device 63, and the other configuration is the same. That is, the first supply device 6 in the fourth embodiment includes a heating device 65, and the heating device 65 includes a high-temperature air hood 651 and a high-temperature air generation device 652 provided so as to cover the upper portion of the fixed amount supply device 63. High-temperature air, such as hot air or hot air, is sent from the high-temperature air generator 652, so that the particles P1 and / or the particles P2 passing through the fixed amount supply device 63 are heated by the high-temperature air and agitated in a state where the temperature is increased. It is resupplied to the container 31. As a result, the temperature inside the stirring vessel 31 rises due to the high temperature of the particles P2 and the like, and the relative humidity decreases, so that the triboelectric charging efficiency of the particle mixture is improved.
[0023]
Embodiment 5 FIG.
FIG. 7 is a partially enlarged perspective view of a frictional charging device according to a fifth embodiment of the present invention. Embodiment 5 is different from Embodiment 4 in that a dust collecting hood 22 and a suction device 23 are provided, and other configurations are the same. In the fifth embodiment, the dust collecting device 2 includes a perforated cylindrical body 21, a dust collecting hood 22 installed outside the perforated cylindrical body 21, and a suction device 23 connected to the dust collecting hood 22. The perforated cylindrical body 21 has a plurality of small holes 211 through which the particles P1 cannot pass but dust adhering to the particles P1 and the particles P2 can pass.
[0024]
When the particle mixture and the particles P2 input from the input hopper 1 (see FIG. 1 and the like) pass through the perforated cylinder 21, the dust adhering to the particles is sucked from the small holes 211 via the dust collecting hood 22. The suction device 23 sucks and removes dust generated in the course of stirring the particles P1 and P2 in the stirring container 31 at the same time. By removing the dust, the particle mixture is easily charged, and has an effect of improving the triboelectric charging efficiency.
[0025]
Embodiment 6 FIG.
8 and 9 illustrate a friction charging device according to a sixth embodiment of the present invention. FIG. 8 is a schematic explanatory view including a partial cross-sectional view of the sixth embodiment, and FIG. 8 is a partially enlarged perspective view of FIG. Embodiment 6 is different from Embodiment 5 in that a blower 24 is provided, and other configurations are the same. The blowing device 24 includes a blowing hood 241 installed on the side of the perforated cylindrical body 21 opposite to the dust collecting hood 22, and a blower 242 connected to the blowing hood 241. The wind blown from the blower 242 to the perforated cylindrical body 21 via the blower hood 241 enters the stirring vessel 31 through the small holes 211, flows the particle mixture and the particles P2, and stirs the particles. By this stirring, the particle mixture is easily charged, and there is an effect that the triboelectric charging efficiency is improved.
[0026]
Embodiment 7 FIG.
FIG. 10 is a partially enlarged perspective view of a frictional charging device according to a seventh embodiment of the present invention. Is the same. The air blown from the blower 242 is heated by the heater 243 and enters the stirring vessel 31 via the blowing hood 241 and the perforated cylindrical body 21, so that the temperature in the stirring vessel 31 increases and the relative humidity decreases. In addition, the particle mixture is more easily charged, and has an effect of further improving the triboelectric charging efficiency.
[0027]
【The invention's effect】
The frictional charging device of the present invention, as described above, the particle mixture containing the sorting target plastic particles and the sorting target plastic particles have the opposite charging polarity and the friction auxiliary particles having a particle size that can be classified from the particle mixture. A stirrer for stirring, a classifier for classifying the mixture stirred by the stirrer into the particle mixture and the friction assisting particles, and an electrostatic device for sorting the target plastic particles from the particle mixture classified by the classifier. The apparatus includes a sorting device and a first supply device that supplies the friction assisting particles classified by the classification device to the stirring device. The friction auxiliary particles used once are classified from the particle mixture, and before the re-supply to the stirring device, the friction auxiliary particles have their charge amount reduced at least by spontaneous discharge. The amount of charge is reduced and re-supplied to the stirring device. As a result, there is an effect that the triboelectric charging efficiency of the sorting target plastic particles and the particle mixture is improved.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view including a partial cross-sectional view of Embodiment 1;
FIG. 2 is a partially enlarged perspective view of FIG.
FIG. 3 is a schematic explanatory view including a partial cross-sectional view of Embodiment 2;
FIG. 4 is a schematic explanatory view including a partial cross-sectional view of Embodiment 3;
FIG. 5 is an explanatory diagram illustrating a charging state of various particles according to a third embodiment.
FIG. 6 is a schematic explanatory view including a partial cross-sectional view of Embodiment 4.
FIG. 7 is a partially enlarged perspective view of a fifth embodiment.
FIG. 8 is a schematic explanatory view including a partial cross-sectional view of Embodiment 6;
9 is a partially enlarged perspective view of FIG.
FIG. 10 is a partially enlarged perspective view of a seventh embodiment.
[Explanation of symbols]
S frictional charging device S, 1 charging hopper, 2 dust collector, 21 perforated cylinder,
22 dust collecting hood, 23 suction device, 241 blower hood, 242 blower,
243 heater, 3 stirrer, 31 stirrer, 312 scraper,
32 motor, 33 belt, 34 angle adjustment device, 4 classifier,
43 container, 5 electrostatic separation device, 55 separation container, 6 first supply device,
61 transfer device, 62 recollection hopper, 63 fixed-quantity supply device, 64 static elimination device,
65 heating device, 651 hot air hood, 652 hot air generator,
7 Second supply device, 71 transfer device, 711 hopper.

Claims (10)

The plastic particle mixture containing the plastic particles to be sorted and the plastic particles to be sorted have reverse charging polarity and the plastic particles mixture is agitated by friction stabilizing particles having a particle size that can be classified with the stirrer, which is stirred by the stirrer. Classifier that classifies the resulting mixture into the plastic particle mixture and the friction assisting particles, an electrostatic sorting device that sorts the plastic particle mixture classified by the classifier, and the friction assisting particles that are classified by the classifier And a first supply device for supplying the toner to the stirring device. The friction charging device according to claim 1, wherein the first supply device includes a static elimination device that reduces a charge amount of the friction auxiliary particles. The friction charging device according to claim 1 or 2, wherein the first supply device includes a heating device that heats the friction auxiliary particles and supplies the friction auxiliary particles whose temperature has increased to the stirring device. . The friction heating device according to claim 3, wherein the heating device is capable of sending out high-temperature air. Of the plastic particle mixture classified by the classification device, the portion that is insufficiently selected by the electrostatic separation device due to insufficient charge amount is supplied to the stirring device or the first supply device. The frictional charging device according to claim 1, further comprising a second supply device that performs the charging. The friction charging device according to claim 5, wherein the first supply device has a function of mixing the portion and the friction auxiliary particles to charge the portion. 2. The frictional charging device according to claim 1, further comprising a dust collector for removing dust adhering to the plastic particle mixture and the friction auxiliary particles, which is located upstream of the stirring device. The dust collector has a plurality of small holes through which the particles constituting the plastic particle mixture cannot pass, but the dust can pass through, and has a perforated body communicating with the stirring vessel of the stirring device; The frictional charging device according to claim 7, further comprising a suction device provided outside the hole to suck the dust from the small hole. 9. The friction charging device according to claim 8, further comprising a blower on the side of the perforated body opposite to the suction device. 10. The friction charging device according to claim 9, wherein the blower is capable of sending out high-temperature air.

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