JP2002066380A - Device for triboelectrifying plastic, and plastic sorting apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for triboelectrifying plastic by which several kinds of crushed plastic chips can be triboelectrified with sufficient charge quantity and then can precisely be separated, and to provide a plastic sorting apparatus using the device. SOLUTION: The device for triboelectrifying several kinds of the crushed plastic chips is provided with a casing 22 arranged in the horizontal direction and having a supply part 21 for the plastic chips, which is formed on the upstream side, and a discharge part 23 of the plastic chips, which is formed on the downstream side, and a rotary screw 27 stirring, which is arranged freely rotatably in the casing 22 and triboelectrifies the plastic chips by stirring. The casing 22 is formed of a tubular body whose cross section of inside wall is regular hexahedron.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic triboelectric charging device for frictionally charging plastic pieces contained in sorted refuse to be sorted by type, and a crushed waste sorting device using the same.

[0002]

2. Description of the Related Art In recent years, while recycling of refuse has been rapidly promoted, a plurality of types of crushed plastic pieces are frictionally charged to sort out a plurality of types of crushed plastic pieces. Plastic pieces are sorted by a plastic sorting apparatus. As a plastic friction charging device for this purpose, there is known a device in which a stirring screw is disposed in a casing formed of a cylindrical body having a circular cross section, and the plastic pieces are stirred to thereby frictionally charge the plastic pieces.

However, in such a plastic frictional charging device, since the inner wall of the casing is formed in a circular cross section, the plastic piece is agitated while being swirled around with the rotation of the agitating screw. The plastic pieces are not sufficiently rubbed with each other, and the plastic pieces may not be sufficiently frictionally charged. However, there is a problem that unseparated plastic pieces and the like are apt to be generated and cannot be separated with high accuracy.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention solves the above-mentioned problems and can frictionally charge a plurality of types of crushed plastic pieces to a sufficient charge amount. It is an object of the present invention to provide a plastic triboelectric charging device capable of separating accurately and a crushed waste sorting device using the same.

[0005]

In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention is arranged laterally, a supply section of a plastic piece is formed on an upstream side, and a downstream section is provided. A plurality of pulverized plastic pieces including a casing having a plastic piece discharging portion formed on the side thereof, and a stirring screw rotatably disposed in the casing and agitating the plastic pieces for triboelectric charging. Wherein the casing is formed from a cylindrical body having a polygonal cross section of an inner wall.

According to the above construction, since the casing is formed of a cylindrical body whose inner wall has a polygonal cross section, the plastic piece is agitated while being rotated while being rotated around the plastic piece by the rotation of the stirring screw. As the plastic pieces rotate, the plastic pieces rotate and receive resistance at the polygonal corners of the inner wall of the casing, and a layer of plastic pieces is formed around the stirring screw. Friction promotes triboelectric charging.

Therefore, a plurality of types of plastic pieces can be triboelectrically charged to a sufficient charge amount, whereby
The plastic pieces can be accurately separated by type using a sorting device.

Further, in the invention described in claim 2, in the above configuration, the polygon is any one of a triangle to a dodecagon. According to the above configuration, since the cross section of the inner wall of the casing is any one of a triangular shape to a dodecagonal shape, the internal angles of the corners of these polygons have a sufficient angle to provide resistance to the plastic pieces, and A layer of plastic pieces can be more easily formed around the screw.

According to a third aspect of the present invention, in the above configuration, a conveying screw that is driven to rotate coaxially with the stirring screw is disposed upstream of the stirring screw, and the screw of the conveying screw is provided. The ratio of the pitch a of the blades to the pitch b of the screw blades of the stirring screw is in a range satisfying 1 <b / a ≦ 10, and an opening / closing member is provided at the discharge portion, and the opening / closing member is closed. A pressure load device is provided so as to urge in a direction.

[0010] According to the above structure, the conveying screw provided with the screw blade having the pitch a smaller than the pitch b of the screw blade of the stirring screw is disposed on the upstream side of the stirring screw. Since the transport speed of the plastic pieces per rotation of the screw is slower than the downstream side where the stirring screw is arranged,
It becomes a state where the plastic pieces are filled around the conveying screw, and the plastic pieces are mainly transported,
On the other hand, since the transport speed of the plastic pieces per rotation of the stirring screw on the downstream side is higher than that on the upstream side where the transporting screw is arranged, a gap is formed between the plastic pieces around the stirring screw and the plastic is removed. Stirring of the pieces is mainly performed. Since a pressure load device is provided on the opening / closing member provided in the discharge unit so as to urge the opening / closing member in the closing direction, a part of the plastic piece conveyed to the discharge unit is pushed back by the pressure applied to the opening / closing member. It is.

Accordingly, the residence time of the plastic piece is increased, and the stirring of the plastic piece is promoted. Furthermore, since the pitch b of the stirring screw is larger than the pitch a of the conveying screw, that is, the above ratio is larger than 1, between the plastic pieces around the stirring screw arranged on the downstream side as described above. Since the gap is formed, the pressure applied to the opening / closing member during operation can be adjusted, whereby the degree of friction of the plastic piece can be controlled.

When the above ratio is 1, only the agitating screw is disposed, and there is no difference in the gap between the plastic pieces between the upstream side and the downstream side. It becomes difficult to adjust the pressure applied to the device.

When the above ratio exceeds 10, the plastic pieces tend to be difficult to be discharged.
If less, the plastic pieces are discharged without agitation.

Further, according to a fourth aspect of the present invention, in the above structure, a plurality of minute holes are formed in a lower wall or a side wall of the casing. According to the above configuration, since a plurality of minute holes are formed in the casing, minute conductive material pieces or fine-grained plastic mixed in the plastic pieces can be removed to the outside of the casing through the minute holes.

According to a fifth aspect of the present invention, a mixture of a conductive material and a plastic piece supplied from a supply unit is provided between a drum electrode and a corona discharge electrode disposed opposite to the drum electrode. Pass through the formed corona discharge field,
A first sorting device that separates the conductive material and the plastic pieces and collects them in the collection section, the plastic friction charging device according to any one of claims 1 to 4, and a plastic piece supplied from the supply section. And a second sorting device that separates a plurality of types of plastic pieces and collects them in a collecting section by passing a sorting electrostatic field formed between the drum electrode and a counter electrode disposed opposite to the drum electrode. And the plastic triboelectric charging device is arranged below the first sorting device, and a collecting section of the plastic piece in the first sorting device and a supply portion of the plastic triboelectric charging device are connected, and
The second sorting device is arranged below the plastic friction charging device, and a discharge unit of the plastic friction charging device is connected to a supply unit of the second sorting device.

According to the above arrangement, a plastic friction charging device having a polygonal cross section of the inner wall of the casing is disposed below the first sorting device for separating the conductive material and the plastic piece. A second sorting device for separating a plurality of types of plastic pieces is disposed below the device, and these are connected, so that the separation of the conductive material and the plastic pieces, the triboelectric charging of the plastic pieces, and the plurality of types of triboelectrically charged pieces are performed. Separation of the plastic pieces can be performed continuously. In addition, since a plurality of types of frictionally charged plastic pieces are continuously separated according to each type, the charged plastic pieces can be separated while maintaining the charge amount, and the plurality of types of plastic pieces can be accurately separated. Can be separated.

Further, since the first sorting device, the plastic triboelectric charging device, and the second sorting device are arranged in the vertical direction, the installation of the device is compared with the conventional device in which the respective devices are connected by a belt conveyor or the like. The area can be reduced, and the cost of the apparatus can be kept low.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a crushed waste sorting apparatus using a plastic friction charging device (hereinafter, simply referred to as a friction charging device) according to the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of a crushed waste sorting apparatus of the present invention, and FIG. 2 is an enlarged view of a triboelectric charging apparatus.
(A) is a cross-sectional view thereof, and (b) of FIG.
It is X-ray arrow sectional drawing.

This crushed waste sorting apparatus separates a copper wire and two types of plastic pieces from a mixture of a crushed copper wire (a linear conductive material) and two different types of plastic pieces. Then, two types of plastic pieces separated from the mixture are frictionally charged, and the two types of frictionally charged plastic pieces are separated and collected for each type.

That is, the crushed waste sorting apparatus is provided with a corona discharge for separating a copper wire and two kinds of plastic pieces from a mixture of a crushed copper wire and two different kinds of plastic pieces. The first using
A sorting device 1 is used to charge two types of plastic pieces separated from a copper wire, such as polyvinyl chloride (PVC) and polyethylene (PE), according to the charging sequence, to charge PVC to a negative polarity and PE to a positive polarity. It comprises a friction charging device 2 and a second sorting device 3 for separating and collecting two types of frictionally charged plastic pieces for each type, and a first sorting device 1, a friction charging device 2, and a second sorting device from above. The devices 3 are arranged in the vertical direction in this order. In addition, copper wire, PVC, PE
For example, a material that has been crushed to 5 mm or less is used.

The first sorting device 1 comprises a fixed-quantity supply section 7 comprising a hopper 4 and a supply plate 6 provided with a vibration device 5, and a metal drum electrode provided rotatably about a horizontal axis and grounded. And a needle-shaped member for forming a corona discharge field H between the drum electrode 8 and the drum electrode 8, which is disposed diagonally above the drum electrode 8 at a downward rotation side and at a predetermined distance from the drum electrode 8. A sorting electrostatic field for compensating for a shortage of the amount of charge of the plastic piece P between the electrode (corona discharge electrode) 9 and the downstream side of the needle-shaped electrode 9 and disposed along the drum electrode 8 to face the drum. Plate electrode 10 forming J
For example, the cathode is connected and the anode is grounded, and the variable resistor 1 is connected to the needle electrode 9 and the plate electrode 10 respectively.
A high-voltage power supply 13 for applying a high voltage to the drum electrode 8 via the first electrode 1; and a plastic piece P arranged below the outer peripheral surface of the drum electrode 8 and adsorbed to the drum electrode 8.
A rotating brush 16 for scraping off and a collecting section 14, 15 for separating the plastic pieces P and the copper wires M separated under the electrostatic field J for sorting separately and collecting them, respectively. It is composed of

In the collecting section 14 of the plastic piece P, there is arranged a static eliminator 17 for neutralizing the plastic piece P by neutralizing the electric charge applied to the plastic piece P in the corona discharge field H.
The friction charging device 2 is disposed below the first sorting device 1, and a supply unit 21 having a fixed amount hopper 19 and a charging unit 20 communicates with the collection unit 14 of the plastic pieces P. In the friction charging device 2, a casing 22 is horizontally arranged horizontally, and the casing 22 is formed of a cylindrical body having a regular hexagonal cross section as shown in FIG. It is formed in a regular hexagon. The supply section 21 is formed upstream of the casing 22.
On the downstream side, an open discharge portion 23 is formed.
In the lower wall of the casing 22, a plurality of fine holes 24 for removing fine particles such as fine copper pieces or fine plastic mixed in the plastic pieces P are formed, and are discharged from the fine holes 24. The fine particles fall onto a discharge device such as a discharge plate 34 disposed below the fine particles and are discharged outside the device.

A screw which is driven to rotate by a driving device 25 such as an inverter or a motor is provided in the casing 22, and the downstream side is formed as a stirring screw 27 in which a screw blade 27B is attached to a screw shaft 26 at a coarse pitch b. The agitator C is formed, and the upstream side is connected to the same screw shaft 26 as the screw blade 28.
A is formed on a transport screw 28 in which A is attached at a pitch a finer than the stirring screw 27, and a transport section D is formed. The ratio b / a of the pitch between the screw blade 27B and the screw blade 28A is set to, for example, 7/1.

The stirring screw 27 and the conveying screw 28 are provided so as to form a predetermined gap between the outer periphery and the inner wall of the casing 22. That is, the agitating screw 27 and the conveying screw 28 are formed such that the rotation trajectories of their outer circumferences have the same diameter, and a predetermined gap is formed between the agitating screw 27 and the inscribed circle of the inner wall of the casing 22. .

An opening / closing member 31 such as an opening / closing door is provided at the discharge portion 23 of the casing 22 so as to cover the discharge portion 23.
Is pivotally supported by a pivoting member 32 and is attached so as to be openable and closable.
A pressure load device 33 such as a hydraulic cylinder is provided so as to urge the valve in the closing direction. That is, the opening / closing member 31
The amount of discharge of the triboelectrically-charged plastic pieces is controlled and supplied to the second sorting device 3 in a constant amount according to the degree of pressure applied to the second sorting device 3. A predetermined pressure, for example, 0.05 MPa or less is applied to the opening / closing member 31 by the pressure load device 33. Therefore, the plastic piece P
Is controlled by the pressure applied to the opening and closing member 31 and the rotation speed of the screw.

Below the frictional charging device 2,
A second sorting device 3 is arranged. This second sorting device 3
Is a supply section 37 comprising a supply plate 36 provided with a vibrating device 35 through which the plastic pieces P are supplied in a fixed amount from the discharge port 23 formed in the frictional charging device 2, and around a horizontal axis near the lower portion of the frictional charging device 2. A metal drum electrode 38 rotatably provided and grounded, a plate-shaped electrode 39 disposed diagonally above the drum electrode 38 to face the drum electrode 38 and forming a sorting electrostatic field K; A high-voltage power supply 40 for applying a high voltage to the plate-like electrode 39 by connecting a cathode to the plate-like electrode 39 and grounding the anode to the plate-like electrode 39, for example, A rotating brush 47 for scraping off the adsorbed plastic pieces P, and the plastic pieces P separated by polarity and charge amount through the separation electrostatic field K under the sorting electrostatic field K are separately separated. And a recovery unit 41. recovering. The collecting section 41 is disposed below the drum electrode 38 and separates and collects a plastic piece P such as PVC charged to a negative polarity, and a first collecting chamber 42 such as PE charged to a positive polarity. A second collection chamber 43 for separating and collecting the plastic pieces P; a first collection chamber 42 and a second collection chamber 43
And a third recovery chamber 44 for recovering unseparated plastic pieces P such as PVC and PE having a small charge amount. In the first collection chamber 42 and the second collection chamber 43, static eliminators 45 for neutralizing the plastic pieces P charged and collected by the frictional charging device 2 are arranged.

At the outlet of the third recovery chamber 44, a transport line 46 such as an air pipe communicating with the charging section 20 of the frictional charging device 2 is provided. The unseparated plastic pieces P collected in the collection chamber 44 are returned to the charging section 20 and subjected to re-separation.

Further, the above-mentioned metal plastic sorting apparatus 1
In the supply section 21 of the triboelectric charging device 2 connected to the collection section 14, the above-described quantitative hopper 19 is supported by a support member such as a support base or a support, and a weight sensor 51 is provided. An opening / closing member 50 such as an opening / closing plate for adjusting the distance is provided. The opening / closing member 50 outputs an output signal detected by the weight sensor 51 from a control unit 53 such as a personal computer, and is operated by an operating device 52 such as a hydraulic cylinder. The opening / closing member 31 provided in the discharge unit 23 is provided with an angle detection sensor 54 for detecting the opening / closing angle of the opening / closing member 31. Feedback to the actuator 52 controls the supply and discharge.

Drum electrode 8 in the first sorting device 1
The two drum electrodes of the drum electrode 38 in the second sorting device 3 are driven to rotate by a common driving device (not shown), for example, a motor. The rotation of the driving device is performed via a power transmission member such as a pulley belt or a sprocket chain wound between a pulley provided on a driving shaft of the driving device and a pulley provided on a rotating shaft of each of the drum electrodes 8 and 38. The rotation speed of each of the drum electrodes 8, 38 is determined by the radius of the pulley of each of the drum electrodes 8, 38. That is, the ratio of the number of rotations of the drum electrode 8 to the number of rotations of the drum electrode 38 is determined by the radius ratio of the pulleys provided on both.
The rotating brush 16 and the rotating brush 47 are driven by different driving devices.

In the above-mentioned crushed waste sorting apparatus, the drum electrode 8 of the first sorting apparatus 1 is grounded, the needle electrode 9 and the plate electrode 10 are connected to the cathode of the high voltage power supply 13 and the anode is grounded. In addition, it is assumed that the drum electrode 38 of the second sorting device 3 is grounded, the cathode of the high voltage power supply 40 is connected to the plate electrode 39, and the anode is grounded.

In the above arrangement, the gas in the non-uniform electric field is ionized by the collisional separation of electrons by using the drum electrode 8 rotated in a predetermined direction in the first sorting device 1 as an anode and the needle electrode 9 as a cathode. A corona discharge field H is formed by corona discharge, and a plate-shaped electrode 10 provided downstream of the needle electrode 9 is used as a cathode to form a sorting electrostatic field J. When a mixture of the crushed plastic pieces P containing PVC and PE and the copper wire M is supplied from the hopper 4 to the supply plate 6 vibrating in the vertical direction by the vibrator 5, the mixture is transported on the flat plate 6. Then, it is dropped on the surface of the drum electrode 8.

The mixture dropped on the surface of the drum electrode 8 is given negative ions by corona discharge from the needle electrode 9 while being moved with the rotation of the drum electrode 8. In this mixture, the copper wire M is given a negative charge by corona discharge while being moved with the rotation of the drum electrode 8, and this negative charge is neutralized by a positive charge from the drum electrode 8 and is given from the drum electrode 8. The repelled positive charge repels the drum electrode 8, jumps away from the drum electrode 8, and is collected by the collection unit 15.

On the other hand, of the mixture, the plastic piece P is adsorbed by the drum electrode 8 because the negative charge given by the corona discharge from the needle electrode 9 remains on the surface, and
The negatively charged plastic pieces P provided by corona discharge are further provided with negative charges in the sorting electrostatic field J formed by the plate-shaped electrodes 10 and are attracted to the drum electrodes 8, so that the plastic electrodes P are attracted by the drum electrodes 8. Move with the rotation of the drum electrode and fall from the drum electrode 8 or are scraped off by the rotating brush 16 and collected by the collection unit 14.

The plastic pieces P collected by the collection unit 14
Is removed by neutralizing the charge provided in the corona discharge field H or the sorting electrostatic field J by the neutralizer 17. Then, the plastic piece P falls to the fixed amount hopper 19 of the frictional charging device 2, and the amount of supply into the casing 22 is adjusted by the opening / closing member 50 provided here, and the fixed amount is supplied into the casing 22 via the charging unit 20. Supplied.

The plastic piece P supplied into the casing 22 is conveyed to the stirring screw 27 side while rotating with the rotation of the conveying screw 28, and is stirred by the rotation of the stirring screw 27 to be mixed with the plastic piece. P are rubbed with each other, and at the same time, a layer of plastic pieces P is formed in a gap formed between the outer periphery of the stirring screw 27 and the inner wall of the casing 22, and the plastic pieces P are also rubbed in this layer. You. Further, a part of the plastic piece P conveyed to the discharge section 23 is pushed back by the pressure applied to the opening / closing member 31, and further stirred and rubbed. As a result, of the plastic pieces P, PVC
Is charged to a negative polarity with a predetermined charge amount, and PE is charged to a positive polarity with a predetermined charge amount. Charged PVC and PE
Is discharged from the outlet 23 in a fixed amount. Fine particles such as fine copper pieces or fine-grained plastic mixed in the plastic pieces P
2 are removed from the minute holes 24 formed in the nozzle 2 and fall on the discharge plate 34 to be discharged out of the apparatus.

Then, the drum electrode 38 rotated in a predetermined direction in the second sorting device 3 is used as an anode, and the plate electrode 39 is used as an anode.
Is used as a cathode, a plastic piece P which is a mixture of charged PVC and PE in a state where a sorting electrostatic field K is formed.
Is supplied from the discharge port 23 of the frictional charging device 2 to the supply plate 36 vibrating in the vertical direction by the vibration device 35, the plastic piece P is transported on the supply plate 36, and the surface of the drum electrode 38 Is dropped.

The plastic piece P dropped on the surface of the drum electrode 38 is moved to the sorting electrostatic field K with the rotation of the drum electrode 38, and the positively charged PE repels the drum electrode 38 as an anode. It is attracted to the plate-shaped electrode 39 side as the cathode, and falls in a direction away from the drum electrode 38,
It is collected in the second collection chamber 43. On the other hand, the negatively charged PVC is sucked by the drum electrode 38 and is discharged to the first collection chamber 4.
2 and also adsorbed on the drum electrode 38.
Are scraped off by the rotating brush 47 and
Collected in 2. Then, unseparated PV with a small charge amount
C and PE are collected in the third collection chamber 44.

The PV collected in the first collection chamber 42
C and the PE recovered in the second recovery chamber 43 are respectively carried out after their respective charges are neutralized by the neutralizer 45. On the other hand, the unseparated PV collected in the third collection chamber 44
C and PE are returned to the charging section 20 by the transport line 46 and are subjected to re-separation.

According to this crushed waste sorting apparatus, since the casing 22 of the frictional charging device 2 is formed of a cylindrical body having a regular hexagonal cross section, the plastic piece P is turned while the stirring screw 27 is driven to rotate. The plastic pieces P are rubbed against each other by stirring, and the plastic pieces P
Is formed in a gap formed between the inner wall of the casing 22 and the outer periphery of the stirring screw 27, and the plastic pieces P are rubbed against each other in this layer to promote friction. Further, since the pressure is applied to the opening / closing member 31 provided in the discharge unit 23, a part of the plastic piece transported to the discharge unit 23 is pushed back by the pressure applied to the opening / closing member 31 and further stirred. Friction is promoted.

As a result, the two types of plastic pieces P are charged to a sufficient charge amount, and are accurately separated by the second sorting device 3 disposed downstream thereof. Further, fine particles such as fine copper pieces or fine plastic mixed in the plastic pieces P separated from the copper wire M in the first sorting device 1 are removed from the fine holes 24 formed in the casing 22. When the two types of plastic pieces P are separated for each type by the second sorting device 3 disposed below, it is possible to prevent the occurrence of sparks due to copper pieces and the decrease in sorting accuracy due to the attachment of fine-grained plastic. .

Further, the first sorting device, the triboelectric charging device 2 and the second sorting device 3 are arranged in this order from the top, and these three members are connected, so that the copper wire and the plastic piece P can be separated and the plastic piece P can be separated. The frictional charging of P and the separation of the two types of plastic pieces P can be continuously performed. Further, since the three devices are arranged vertically, the installation area of the devices can be reduced.

The casing according to the present invention has a cross section of 6
Comparing the accuracy of plastic separation between the rectangular friction charging device and the conventional plastic having a circular cross section, when the casing has a regular hexagonal cross section, for example, PVC has a purity of 99.7% by mass and a recovery of 99.7% by mass. Rate of 99.7% by mass, purity of PE is 99.6% by mass, and recovery rate of 90.5% by mass, while extremely high separation accuracy is obtained. For PVC, purity 99% by mass,
The recovery was 81.1% by mass, the purity of PE was 97.2% by mass, and the recovery was 83.3% by mass, which was low separation accuracy.

In the above embodiment, the casing 22 is formed of a cylindrical body having a regular hexagonal cross section. However, if the inner wall of the casing 22 is a polygon such as a regular hexagon, the outer periphery of the casing 22 may be shaped. May be circular or the like. Further, the casing 22 may be installed with the discharge portion 23 side facing obliquely upward. Further, the supply unit of the frictional charging device 2 is
And the input section 20 are formed separately, but the input section 20 is supported by a column or the like, and the weight sensor 51 and the opening / closing member 50
May be provided, and the charging section 20 may be a fixed-rate hopper. Further, the screw such as the stirring screw 27 may be arranged so that the outer periphery thereof hardly forms a gap between the screw and the inner wall of the casing 22. In this case, the screw is formed at the corner of the polygon such as the regular hexagon. A layer of plastic pieces P is formed.

Although the casing 22 has the minute holes 24 formed in the lower wall thereof, the minute holes 24 may be formed in the side wall when the minute holes 24 are formed. Furthermore, the stirring screw 27
Screw 2 to improve the stirring power
7, a plurality of protrusions can be added to the screw blade 27B or the screw shaft 26, for example, a protrusion protruding in that direction is provided on the discharge portion side of the screw blade 27B, and the screw shaft 26 protrudes in the radial direction. Protruded projections may be provided.

Further, regarding the driving device, the drum electrode 8
And the rotating brush 16 and the drum electrode 38 and the rotating brush 47 may be rotationally driven by a common driving device.

FIG. 3 shows another embodiment of the frictional charging device according to the present invention. In the frictional charging device shown in FIG. 2, screw blades 27B are provided on the screw shaft 26 at equal pitches for stirring. The screw 27 is formed. That is, the pitch ratio b / a is set to 1. Even in the frictional charging device provided with the stirring screw 27, the plastic piece can be frictionally charged to a sufficient charge amount even if the pitch ratio is not as large as 1 <b / a. The other configuration in FIG. 3 is the same as that in FIG.

FIG. 4 shows a plastic sorting apparatus provided with a conventional frictional charging device, in which a casing of a frictional charging device 60 is formed of a cylindrical body having a circular cross section. Friction charging device For example, a friction charging device shown in FIG. 2 can be used in place of the friction charging device 60 in FIG. That is, the frictional charging device according to the present invention may be used for a plastic sorting device that frictionally charges a plastic piece separated from a mixture of a conductive material and a plastic piece in advance and separates a plurality of types of plastic pieces by type. it can. The other configuration of the device in FIG. 4 is the same as that of the second sorting device 3 shown in FIG. 1, and therefore, only the reference numeral is attached and the description is omitted.

As described above, the frictional charging device of the present invention
In addition to a crushed waste sorting device that continuously separates conductive objects and plastic pieces, frictionally charges plastic pieces, and separates multiple types of frictionally charged plastic pieces, it also has frictional and frictionally charged plastic pieces. The present invention can also be used for a plastic sorting device for separating a plurality of types of plastic pieces.

In the frictional charging device of the present invention, the driving device for rotating the stirring screw may be a motor, an inverter, or the like. An inverter is preferred because the rotation speed of the stirring screw can be changed according to difficulty or the like.

The number of rotations of the stirring screw is 20
The control can be performed in the range of 0 to 3600 rpm, but for example, in order to collect the plastic pieces at a collection rate of 80% by mass or more, 200 to 3000 rpm is preferable. As the rotation speed of the stirring screw increases, the charge amount of the plastic piece per unit time increases.However, since the residence time of the plastic piece in the casing is shortened, the rotation speed is determined by the residence time of the plastic piece in the casing. It is preferable to determine within the above range in consideration of a desired charge amount and the like.

The pressure applied to the opening / closing member provided at the discharge section of the frictional charging device is preferably 0.05 MPa or less, more preferably 0.005 to 0.05 MPa. If this pressure exceeds 0.05 MPa, the pressure may become too high and the plastic pieces may start to melt due to frictional heat between the plastic pieces.

[0053]

As described above, according to the frictional charging device of the present invention, since the casing is formed of a cylindrical body having a polygonal cross section of the inner wall, the plastic piece is formed together with this by rotating the stirring screw. While being swirled around and stirred, the plastic pieces are rubbed against each other, and the plastic piece is swirled and receives resistance at the polygonal corners of the inner wall of the casing, forming a layer of plastic pieces around the stirring screw. In this layer, the plastic pieces are rubbed against each other to promote triboelectric charging.

Therefore, a plurality of types of plastic pieces can be triboelectrically charged to a sufficient charge amount, whereby
Plastic pieces can be accurately separated by type using a plastic sorting device.

According to the second aspect of the present invention, a layer of plastic pieces can be more easily formed around the stirring screw. According to the third aspect of the present invention, the agitation of the plastic piece is promoted by increasing the residence time of the plastic piece, and the pressure applied to the opening / closing member during operation is adjusted. Friction can be controlled.

According to the fourth aspect of the present invention, minute conductive material pieces or fine-grained plastic mixed in the plastic pieces can be removed out of the casing through the fine holes.

Further, according to the crushed waste sorting apparatus of the present invention, it is possible to continuously perform the separation of the conductive material and the plastic pieces, the frictional charging of the plastic pieces, and the separation of a plurality of frictionally charged plastic pieces. it can. In addition, since a plurality of types of frictionally charged plastic pieces are continuously separated according to each type, the charged plastic pieces can be separated while maintaining the charge amount, and the plurality of types of plastic pieces can be accurately separated. Can be separated. Further, as compared with a conventional apparatus in which the respective apparatuses are connected by a belt conveyor or the like, the installation area of the apparatus is reduced, and the cost of the apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a crushed waste sorting apparatus according to the present invention.

FIG. 2 is an enlarged view of a main part of the crushed waste sorting apparatus, wherein FIG. 2 (a) is a cross-sectional view of a friction charging device, and FIG. 2 (b) is a cross-sectional view taken along line XX of FIG.

FIG. 3 is a sectional view showing another embodiment of the frictional charging device according to the present invention.

FIG. 4 is a cross-sectional view showing a plastic sorting device using a conventional frictional charging device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st sorting device 2 Friction charging device 3 2nd sorting device 4 Hopper 5 Vibration device 6 Supply plate 7 Quantitative supply part 8 Drum electrode 9 Needle electrode 10 Plate electrode 11 Variable resistance 13 High voltage power supply 14 Collection part 15 Collection part Reference Signs List 16 rotating brush 17 static eliminator 19 constant-quantity hopper 20 input unit 21 supply unit 22 casing 23 discharge unit 24 microhole 25 drive unit 26 screw shaft 27 stirring screw 27B screw blade 28 transfer screw 28A screw blade 31 opening / closing member 32 pivot member 33 Pressure load device 34 Discharge plate 35 Vibration device 36 Supply plate 37 Supply unit 38 Drum electrode 39 Plate electrode 40 High voltage power supply 41 Recovery unit 42 First recovery chamber 43 Second recovery chamber 44 Third recovery chamber 45 Static eliminator 46 Transport Line 47 rotating brush 50 opening / closing member 51 weight sensor 5 2 Actuator 53 Controller 54 Angle detection sensor 60 Friction charging device P Plastic piece M Copper wire C Stirrer D Transporter H Corona discharge field J Sorting electrostatic field K Sorting electrostatic field

[Procedure amendment]

[Submission date] May 25, 2001 (2001.5.2)
5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

Patent application title: Plastic Friction Charging Device and Plastic Sorting Equipment Using It

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic triboelectric charging device for triboelectrically charging plastic pieces contained in sorted refuse to be sorted by type, and uses the same.
Related to plastic sorting equipment .

[0002]

2. Description of the Related Art In recent years, while recycling of refuse has been rapidly promoted, a plurality of types of crushed plastic pieces are frictionally charged to sort out a plurality of types of crushed plastic pieces. Plastic pieces are sorted by a plastic sorting apparatus. As a plastic friction charging device for this purpose, there is known a device in which a stirring screw is disposed in a casing formed of a cylindrical body having a circular cross section, and the plastic pieces are stirred to thereby frictionally charge the plastic pieces.

However, in such a plastic frictional charging device, since the inner wall of the casing is formed in a circular cross section, the plastic piece is agitated while being swirled around with the rotation of the agitating screw. The plastic pieces are not sufficiently rubbed with each other, and the plastic pieces may not be sufficiently frictionally charged. However, there is a problem that unseparated plastic pieces and the like are apt to be generated and cannot be separated with high accuracy.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention solves the above-mentioned problems and can frictionally charge a plurality of types of crushed plastic pieces to a sufficient charge amount. plastic frictional charging device can be accurately separated and plastic using the same
The purpose is to provide screening equipment .

[0005]

In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention is arranged laterally, a supply section of a plastic piece is formed on an upstream side, and a downstream section is provided. A plurality of pulverized plastic pieces including a casing having a plastic piece discharging portion formed on the side thereof, and a stirring screw rotatably disposed in the casing and agitating the plastic pieces for triboelectric charging. Wherein the casing is formed from a cylindrical body having a polygonal cross section of an inner wall.

According to the above construction, since the casing is formed of a cylindrical body whose inner wall has a polygonal cross section, the plastic piece is agitated while being rotated while being rotated around the plastic piece by the rotation of the stirring screw. As the plastic pieces rotate, the plastic pieces rotate and receive resistance at the polygonal corners of the inner wall of the casing, and a layer of plastic pieces is formed around the stirring screw. Friction promotes triboelectric charging.

Therefore, a plurality of types of plastic pieces can be triboelectrically charged to a sufficient charge amount, whereby
The plastic pieces can be accurately separated by type using a sorting device.

Further, in the invention described in claim 2, in the above configuration, the polygon is any one of a triangle to a dodecagon. According to the above configuration, since the cross section of the inner wall of the casing is any one of a triangular shape to a dodecagonal shape, the internal angles of the corners of these polygons have a sufficient angle to provide resistance to the plastic pieces, and A layer of plastic pieces can be more easily formed around the screw.

According to a third aspect of the present invention, in the above configuration, a conveying screw that is driven to rotate coaxially with the stirring screw is disposed upstream of the stirring screw, and the screw of the conveying screw is provided. The ratio of the pitch a of the blades to the pitch b of the screw blades of the stirring screw is in a range satisfying 1 <b / a ≦ 10, and an opening / closing member is provided at the discharge portion, and the opening / closing member is closed. A pressure load device is provided so as to urge in a direction.

[0010] According to the above structure, the conveying screw provided with the screw blade having the pitch a smaller than the pitch b of the screw blade of the stirring screw is disposed on the upstream side of the stirring screw. Since the transport speed of the plastic pieces per rotation of the screw is slower than the downstream side where the stirring screw is arranged,
It becomes a state where the plastic pieces are filled around the conveying screw, and the plastic pieces are mainly transported,
On the other hand, since the transport speed of the plastic pieces per rotation of the stirring screw on the downstream side is higher than that on the upstream side where the transporting screw is arranged, a gap is formed between the plastic pieces around the stirring screw and the plastic is removed. Stirring of the pieces is mainly performed. Since a pressure load device is provided on the opening / closing member provided in the discharge unit so as to urge the opening / closing member in the closing direction, a part of the plastic piece conveyed to the discharge unit is pushed back by the pressure applied to the opening / closing member. It is.

Accordingly, the residence time of the plastic piece is increased, and the stirring of the plastic piece is promoted. Furthermore, since the pitch b of the stirring screw is larger than the pitch a of the conveying screw, that is, the above ratio is larger than 1, between the plastic pieces around the stirring screw arranged on the downstream side as described above. Since the gap is formed, the pressure applied to the opening / closing member during operation can be adjusted, whereby the degree of friction of the plastic piece can be controlled.

When the above ratio is 1, only the agitating screw is disposed, and there is no difference in the gap between the plastic pieces between the upstream side and the downstream side. It becomes difficult to adjust the pressure applied to the device.

When the above ratio exceeds 10, the plastic pieces tend to be difficult to be discharged.
If less, the plastic pieces are discharged without agitation.

Further, according to a fourth aspect of the present invention, in the above structure, a plurality of minute holes are formed in a lower wall or a side wall of the casing. According to the above configuration, since a plurality of minute holes are formed in the casing, minute conductive material pieces or fine-grained plastic mixed in the plastic pieces can be removed to the outside of the casing through the minute holes.

According to a fifth aspect of the present invention, a mixture of a conductive material and a plastic piece supplied from a supply unit is provided between a drum electrode and a corona discharge electrode disposed opposite to the drum electrode. Pass through the formed corona discharge field,
A first sorting device that separates the conductive material and the plastic pieces and collects them in the collection section, the plastic friction charging device according to any one of claims 1 to 4, and a plastic piece supplied from the supply section. And a second sorting device that separates a plurality of types of plastic pieces and collects them in a collecting section by passing a sorting electrostatic field formed between the drum electrode and a counter electrode disposed opposite to the drum electrode. And the plastic triboelectric charging device is arranged below the first sorting device, and a collecting section of the plastic piece in the first sorting device and a supply portion of the plastic triboelectric charging device are connected, and
The second sorting device is arranged below the plastic friction charging device, and a discharge unit of the plastic friction charging device is connected to a supply unit of the second sorting device.

According to the above arrangement, a plastic friction charging device having a polygonal cross section of the inner wall of the casing is disposed below the first sorting device for separating the conductive material and the plastic piece. A second sorting device for separating a plurality of types of plastic pieces is disposed below the device, and these are connected, so that the separation of the conductive material and the plastic pieces, the triboelectric charging of the plastic pieces, and the plurality of types of triboelectrically charged pieces are performed. Separation of the plastic pieces can be performed continuously. In addition, since a plurality of types of frictionally charged plastic pieces are continuously separated according to each type, the charged plastic pieces can be separated while maintaining the charge amount, and the plurality of types of plastic pieces can be accurately separated. Can be separated.

Further, since the first sorting device, the plastic triboelectric charging device, and the second sorting device are arranged in the vertical direction, the installation of the device is compared with the conventional device in which the respective devices are connected by a belt conveyor or the like. The area can be reduced, and the cost of the apparatus can be kept low.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a plastic sorting apparatus using a plastic friction charging device according to the present invention (hereinafter simply referred to as a friction charging device) will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of a crushed waste sorting apparatus of the present invention, and FIG. 2 is an enlarged view of a triboelectric charging apparatus.
(A) is a cross-sectional view thereof, and (b) of FIG.
It is X-ray arrow sectional drawing.

This plastic sorting equipment separates a copper wire and two types of plastic pieces from a mixture of a crushed copper wire (linear conductive material) and two different types of plastic pieces. , Separated from the mixture 2
In this method, two types of plastic pieces are frictionally charged, and two kinds of frictionally charged plastic pieces are separated and collected for each type.

That is, this plastic sorting equipment is
A first sorting device 1 utilizing corona discharge for separating a copper wire and two types of plastic pieces from a mixture of a copper wire in which a plastic-coated waste wire is crushed and two different types of plastic pieces, and a copper wire Two kinds of plastic pieces separated from PVC, for example, polyvinyl chloride (PVC) and polyethylene (PE), according to the charging sequence, the PVC to the negative polarity, the PE
And a second sorting device 3 for separating and collecting two types of frictionally charged plastic pieces by type, and a first sorting device 1 from above. , A triboelectric charging device 2 and a second sorting device 3 in the vertical direction. In addition, copper wire, PVC, P
As E, for example, one crushed to 5 mm or less is used.

The first sorting device 1 comprises a fixed-quantity supply section 7 comprising a hopper 4 and a supply plate 6 provided with a vibration device 5, and a metal drum electrode provided rotatably about a horizontal axis and grounded. And a needle-shaped member for forming a corona discharge field H between the drum electrode 8 and the drum electrode 8, which is disposed diagonally above the drum electrode 8 at a downward rotation side and at a predetermined distance from the drum electrode 8. A sorting electrostatic field for compensating for a shortage of the amount of charge of the plastic piece P between the electrode (corona discharge electrode) 9 and the downstream side of the needle-shaped electrode 9 and disposed along the drum electrode 8 to face the drum. Plate electrode 10 forming J
For example, the cathode is connected and the anode is grounded, and the variable resistor 1 is connected to the needle electrode 9 and the plate electrode 10 respectively.
A high-voltage power supply 13 for applying a high voltage to the drum electrode 8 via the first electrode 1; and a plastic piece P arranged below the outer peripheral surface of the drum electrode 8 and adsorbed to the drum electrode 8.
A rotating brush 16 for scraping off and a collecting section 14, 15 for separating the plastic pieces P and the copper wires M separated under the electrostatic field J for sorting separately and collecting them, respectively. It is composed of

In the collecting section 14 of the plastic piece P, there is arranged a static eliminator 17 for neutralizing the plastic piece P by neutralizing the electric charge applied to the plastic piece P in the corona discharge field H.
The friction charging device 2 is disposed below the first sorting device 1, and a supply unit 21 having a fixed amount hopper 19 and a charging unit 20 communicates with the collection unit 14 of the plastic pieces P. In the friction charging device 2, a casing 22 is horizontally arranged horizontally, and the casing 22 is formed of a cylindrical body having a regular hexagonal cross section as shown in FIG. It is formed in a regular hexagon. The supply section 21 is formed upstream of the casing 22.
On the downstream side, an open discharge portion 23 is formed.
In the lower wall of the casing 22, a plurality of fine holes 24 for removing fine particles such as fine copper pieces or fine plastic mixed in the plastic pieces P are formed, and are discharged from the fine holes 24. The fine particles fall onto a discharge device such as a discharge plate 34 disposed below the fine particles and are discharged outside the device.

A screw which is driven to rotate by a driving device 25 such as an inverter or a motor is provided in the casing 22, and the downstream side is formed as a stirring screw 27 in which a screw blade 27B is attached to a screw shaft 26 at a coarse pitch b. The agitator C is formed, and the upstream side is connected to the same screw shaft 26 as the screw blade 28.
A is formed on a transport screw 28 in which A is attached at a pitch a finer than the stirring screw 27, and a transport section D is formed. The ratio b / a of the pitch between the screw blade 27B and the screw blade 28A is set to, for example, 7/1.

The stirring screw 27 and the conveying screw 28 are provided so as to form a predetermined gap between the outer periphery and the inner wall of the casing 22. That is, the agitating screw 27 and the conveying screw 28 are formed such that the rotation trajectories of their outer circumferences have the same diameter, and a predetermined gap is formed between the agitating screw 27 and the inscribed circle of the inner wall of the casing 22. .

An opening / closing member 31 such as an opening / closing door is provided at the discharge portion 23 of the casing 22 so as to cover the discharge portion 23.
Is pivotally supported by a pivoting member 32 and is attached so as to be openable and closable.
A pressure load device 33 such as a hydraulic cylinder is provided so as to urge the valve in the closing direction. That is, the opening / closing member 31
The amount of discharge of the triboelectrically-charged plastic pieces is controlled and supplied to the second sorting device 3 in a constant amount according to the degree of pressure applied to the second sorting device 3. A predetermined pressure, for example, 0.05 MPa or less is applied to the opening / closing member 31 by the pressure load device 33. Therefore, the plastic piece P
Is controlled by the pressure applied to the opening and closing member 31 and the rotation speed of the screw.

Below the frictional charging device 2,
A second sorting device 3 is arranged. This second sorting device 3
Is a supply section 37 comprising a supply plate 36 provided with a vibrating device 35 through which the plastic pieces P are supplied in a fixed amount from the discharge port 23 formed in the frictional charging device 2, and around a horizontal axis near the lower portion of the frictional charging device 2. A metal drum electrode 38 rotatably provided and grounded, a plate-shaped electrode 39 disposed diagonally above the drum electrode 38 to face the drum electrode 38 and forming a sorting electrostatic field K; A high-voltage power supply 40 for applying a high voltage to the plate-shaped electrode 39 by connecting a cathode to the plate-shaped electrode 39 and grounding the anode, for example, A rotating brush 47 for scraping off the adsorbed plastic pieces P, and the plastic pieces P separated by polarity and charge amount through the separating electrostatic field K under the sorting electrostatic field K are separately separated. And a recovery unit 41. recovering. The collection unit 41 is disposed below the drum electrode 38 and separates and collects a plastic piece P such as PVC charged to a negative polarity, and a first collection chamber 42 such as PE charged to a positive polarity. A second collection chamber 43 for separating and collecting the plastic pieces P; a first collection chamber 42 and a second collection chamber 43
And a third recovery chamber 44 for recovering unseparated plastic pieces P such as PVC and PE having a small charge amount. In the first collection chamber 42 and the second collection chamber 43, static eliminators 45 for neutralizing the plastic pieces P charged and collected by the friction charging device 2 are arranged.

At the outlet of the third recovery chamber 44, a transport line 46 such as an air pipe communicating with the charging section 20 of the frictional charging device 2 is provided. The unseparated plastic pieces P collected in the collection chamber 44 are returned to the charging section 20 and subjected to re-separation.

Further, the collection unit 14 of the first sorting device 1
In the supply unit 21 of the frictional charging device 2 connected to the apparatus, the quantitative hopper 19 is supported by a support member such as a support base or a support, and a weight sensor 51 is provided.
There is provided an opening / closing member 50 such as an opening / closing plate for adjusting the degree of opening. The opening / closing member 50 includes a weight sensor 51
The output signal detected by the control unit 5 such as a personal computer
3 and is operated by an operating device 52 such as a hydraulic cylinder. The opening / closing member 31 provided in the discharge unit 23 is provided with an angle detection sensor 54 for detecting the opening / closing angle of the opening / closing member 31. Feedback to the actuator 52 controls the supply and discharge.

Drum electrode 8 in the first sorting device 1
The two drum electrodes of the drum electrode 38 in the second sorting device 3 are driven to rotate by a common driving device (not shown), for example, a motor. The rotation of the driving device is performed via a power transmission member such as a pulley belt or a sprocket chain wound between a pulley provided on a driving shaft of the driving device and a pulley provided on a rotating shaft of each of the drum electrodes 8 and 38. The rotation speed of each of the drum electrodes 8, 38 is determined by the radius of the pulley of each of the drum electrodes 8, 38. That is, the ratio of the number of rotations of the drum electrode 8 to the number of rotations of the drum electrode 38 is determined by the radius ratio of the pulleys provided on both.
The rotating brush 16 and the rotating brush 47 are driven by different driving devices.

In the above-mentioned crushed waste sorting apparatus, the drum electrode 8 of the first sorting apparatus 1 is grounded, the needle electrode 9 and the plate electrode 10 are connected to the cathode of the high voltage power supply 13 and the anode is grounded. In addition, it is assumed that the drum electrode 38 of the second sorting device 3 is grounded, the cathode of the high voltage power supply 40 is connected to the plate electrode 39, and the anode is grounded.

In the above arrangement, the gas in the non-uniform electric field is ionized by the collisional separation of electrons by using the drum electrode 8 rotated in a predetermined direction in the first sorting device 1 as an anode and the needle electrode 9 as a cathode. A corona discharge field H is formed by corona discharge, and a plate-shaped electrode 10 provided downstream of the needle electrode 9 is used as a cathode to form a sorting electrostatic field J. When a mixture of the crushed plastic pieces P containing PVC and PE and the copper wire M is supplied from the hopper 4 to the supply plate 6 vibrating in the vertical direction by the vibrator 5, the mixture is transported on the flat plate 6. Then, it is dropped on the surface of the drum electrode 8.

The mixture dropped on the surface of the drum electrode 8 is given negative ions by corona discharge from the needle electrode 9 while being moved with the rotation of the drum electrode 8. In this mixture, the copper wire M is given a negative charge by corona discharge while being moved with the rotation of the drum electrode 8, and this negative charge is neutralized by a positive charge from the drum electrode 8 and is given from the drum electrode 8. The repelled positive charge repels the drum electrode 8, jumps away from the drum electrode 8, and is collected by the collection unit 15.

On the other hand, of this mixture, the plastic piece P is negatively charged by corona discharge from the needle electrode 9.
Since the electric charge remains, the plastic piece P, which is adsorbed on the drum electrode 8 and lacks the negative electric charge given by the corona discharge, has a mirror image due to the polarization action in the sorting electrostatic field J formed by the plate-shaped electrode 10. The increase in force and the electrostatic force
It is absorbed by the drum electrode 8, moves with the rotation of the drum electrode 8, drops from the drum electrode 8, or is scraped off by the rotating brush 16 and collected by the collection unit 14.

The plastic pieces P collected by the collection unit 14
Is removed by neutralizing the charge provided in the corona discharge field H or the sorting electrostatic field J by the neutralizer 17. Then, the plastic piece P falls to the fixed amount hopper 19 of the frictional charging device 2, and the amount of supply into the casing 22 is adjusted by the opening / closing member 50 provided here, and the fixed amount is supplied into the casing 22 via the charging unit 20. Supplied.

The plastic piece P supplied into the casing 22 is conveyed to the stirring screw 27 side while rotating with the rotation of the conveying screw 28, and is stirred by the rotation of the stirring screw 27 to be mixed with the plastic piece. P are rubbed with each other, and at the same time, a layer of plastic pieces P is formed in a gap formed between the outer periphery of the stirring screw 27 and the inner wall of the casing 22, and the plastic pieces P are also rubbed in this layer. You. Further, a part of the plastic piece P conveyed to the discharge section 23 is pushed back by the pressure applied to the opening / closing member 31, and further stirred and rubbed. As a result, of the plastic pieces P, PVC
Is charged to a negative polarity with a predetermined charge amount, and PE is charged to a positive polarity with a predetermined charge amount. Charged PVC and PE
Is discharged from the outlet 23 in a fixed amount. Fine particles such as fine copper pieces or fine-grained plastic mixed in the plastic pieces P
2 are removed from the minute holes 24 formed in the nozzle 2 and fall on the discharge plate 34 to be discharged out of the apparatus.

Then, the drum electrode 38 rotated in a predetermined direction in the second sorting device 3 is used as an anode, and the plate electrode 39 is used as an anode.
Is used as a cathode, a plastic piece P which is a mixture of charged PVC and PE in a state where a sorting electrostatic field K is formed.
Is supplied from the discharge port 23 of the frictional charging device 2 to the supply plate 36 vibrating in the vertical direction by the vibration device 35, the plastic piece P is transported on the supply plate 36, and the surface of the drum electrode 38 Is dropped.

The plastic piece P dropped on the surface of the drum electrode 38 is moved to the sorting electrostatic field K with the rotation of the drum electrode 38, and the positively charged PE repels the drum electrode 38 as an anode. It is attracted to the plate-shaped electrode 39 side as the cathode, and falls in a direction away from the drum electrode 38,
It is collected in the second collection chamber 43. On the other hand, the negatively charged PVC is sucked by the drum electrode 38 and is discharged to the first collection chamber 4.
2 and also adsorbed on the drum electrode 38.
Are scraped off by the rotating brush 47 and
Collected in 2. Then, unseparated PV with a small charge amount
C and PE are collected in the third collection chamber 44.

The PV collected in the first collection chamber 42
C and the PE recovered in the second recovery chamber 43 are respectively carried out after their respective charges are neutralized by the neutralizer 45. On the other hand, the unseparated PV collected in the third collection chamber 44
C and PE are returned to the charging section 20 by the transport line 46 and are subjected to re-separation.

According to this plastic sorting equipment , since the casing 22 of the frictional charging device 2 is formed of a cylindrical body having a regular hexagonal cross section, the plastic piece P is swirled by the rotational drive of the stirring screw 27. As a result, the plastic pieces P are rubbed against each other, and the layer of the plastic pieces P is
The plastic pieces P are rubbed against each other in the gap formed between the plastic pieces P and the outer periphery of the plastic piece 7 to promote friction. Further, since the pressure is applied to the opening / closing member 31 provided in the discharge unit 23, a part of the plastic piece transported to the discharge unit 23 is pushed back by the pressure applied to the opening / closing member 31 and further stirred. Friction is promoted.

As a result, the two types of plastic pieces P are charged to a sufficient charge amount, and are accurately separated by the second sorting device 3 disposed downstream thereof. Further, fine particles such as fine copper pieces or fine plastic mixed in the plastic pieces P separated from the copper wire M in the first sorting device 1 are removed from the fine holes 24 formed in the casing 22. When the two types of plastic pieces P are separated for each type by the second sorting device 3 disposed below, it is possible to prevent the occurrence of sparks due to copper pieces and the decrease in sorting accuracy due to the attachment of fine-grained plastic. .

Further, the first sorting device, the triboelectric charging device 2 and the second sorting device 3 are arranged in this order from the top, and these three members are connected, so that the copper wire and the plastic piece P can be separated and the plastic piece P can be separated. The frictional charging of P and the separation of the two types of plastic pieces P can be continuously performed. Further, since the three devices are arranged vertically, the installation area of the devices can be reduced.

The casing according to the present invention has a cross section of 6
Comparing the accuracy of plastic separation between the rectangular friction charging device and the conventional plastic having a circular cross section, when the casing has a regular hexagonal cross section, for example, PVC has a purity of 99.7% by mass and a recovery of 99.7% by mass. Rate of 99.7% by mass, purity of PE is 99.6% by mass, and recovery rate of 90.5% by mass, while extremely high separation accuracy is obtained. 99% by weight with the PVC, the recovery rate 81.1 wt%, purity 97.2 mass% for PE, were recovered 83.3% by weight and a low separation accuracy.

In the above embodiment, the casing 22 is formed of a cylindrical body having a regular hexagonal cross section. However, if the inner wall of the casing 22 is a polygon such as a regular hexagon, the outer periphery of the casing 22 may be shaped. May be circular or the like. Further, the casing 22 may be installed with the discharge portion 23 side facing obliquely upward. Further, the supply unit of the frictional charging device 2 is
And the input section 20 are formed separately, but the input section 20 is supported by a column or the like, and the weight sensor 51 and the opening / closing member 50
May be provided, and the charging section 20 may be a fixed-rate hopper. Further, the screw such as the stirring screw 27 may be arranged so that the outer periphery thereof hardly forms a gap between the screw and the inner wall of the casing 22. In this case, the screw is formed at the corner of the polygon such as the regular hexagon. A layer of plastic pieces P is formed.

Although the casing 22 has the minute holes 24 formed in the lower wall thereof, the minute holes 24 may be formed in the side wall when the minute holes 24 are formed. Furthermore, the stirring screw 27
Screw 2 to improve the stirring power
7, a plurality of protrusions can be added to the screw blade 27B or the screw shaft 26, for example, a protrusion protruding in that direction is provided on the discharge portion side of the screw blade 27B, and the screw shaft 26 protrudes in the radial direction. Protruded projections may be provided.

Further, regarding the driving device, the drum electrode 8
And the rotating brush 16 and the drum electrode 38 and the rotating brush 47 may be rotationally driven by a common driving device.

FIG. 3 shows another embodiment of the frictional charging device according to the present invention. In the frictional charging device shown in FIG. 2, screw blades 27B are provided on the screw shaft 26 at equal pitches for stirring. The screw 27 is formed. That is, the pitch ratio b / a is set to 1. Even in the frictional charging device provided with the stirring screw 27, the plastic piece can be frictionally charged to a sufficient charge amount even if the pitch ratio is not as large as 1 <b / a. Other structures in Fig. 3 is similar to FIG. 2, their description will be omitted by reference numeral only.

In the frictional charging device of the present invention, a driving device for rotating the stirring screw is usually used.
Motor of the motor or may be any of the inverter control of the motor but, since it is possible to vary the speed of the stirring screw in accordance with the plastic piece and small dimensions, chargeability of difficulty which is an object to be sorted matter, the inverter control Is preferred.

The number of rotations of the stirring screw is 20
The control can be performed in the range of 0 to 3600 rpm, but for example, in order to collect the plastic pieces at a collection rate of 80% by mass or more, 200 to 3000 rpm is preferable. As the rotation speed of the stirring screw increases, the charge amount of the plastic piece per unit time increases.However, since the residence time of the plastic piece in the casing is shortened, the rotation speed is determined by the residence time of the plastic piece in the casing. It is preferable to determine within the above range in consideration of a desired charge amount and the like.

The pressure applied to the opening / closing member provided at the discharge section of the frictional charging device is preferably 0.05 MPa or less, more preferably 0.005 to 0.05 MPa. If this pressure exceeds 0.05 MPa, the pressure may become too high and the plastic pieces may start to melt due to frictional heat between the plastic pieces.

[0051]

As described above, according to the frictional charging device of the present invention, since the casing is formed of a cylindrical body having a polygonal cross section of the inner wall, the plastic piece is formed together with this by rotating the stirring screw. While being swirled around and stirred, the plastic pieces are rubbed against each other, and the plastic piece is swirled and receives resistance at the polygonal corners of the inner wall of the casing, forming a layer of plastic pieces around the stirring screw. In this layer, the plastic pieces are rubbed against each other to promote triboelectric charging.

Therefore, a plurality of types of plastic pieces can be triboelectrically charged to a sufficient charge amount, whereby
Plastic pieces can be accurately separated by type using a plastic sorting device.

According to the second aspect of the present invention, a plastic piece layer can be more easily formed around the stirring screw. According to the third aspect of the present invention, the agitation of the plastic piece is promoted by increasing the residence time of the plastic piece, and the pressure applied to the opening / closing member during operation is adjusted. Friction can be controlled.

Further, according to the invention described in claim 4, minute conductive material pieces or fine-grained plastic mixed in the plastic pieces can be removed out of the casing through the minute holes.

Further, according to the plastic sorting equipment of the present invention, it is possible to continuously perform separation of the conductive material and the plastic piece, frictional charging of the plastic piece, and separation of a plurality of types of frictionally charged plastic pieces. . In addition, since a plurality of types of frictionally charged plastic pieces are continuously separated according to each type, the charged plastic pieces can be separated while maintaining the charge amount, and the plurality of types of plastic pieces can be accurately separated. Can be separated. Further, as compared with a conventional apparatus in which the respective apparatuses are connected by a belt conveyor or the like, the installation area of the apparatus is reduced, and the cost of the apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing one embodiment of a plastic sorting facility according to the present invention.

FIG. 2 is an enlarged view of a main part of the plastic sorting equipment, in which (a) is a cross-sectional view of a frictional charging device, and (b) is a cross-sectional view taken along line XX of FIG.

[Figure 3] Ru sectional view showing another embodiment of the frictional charging device according to the present invention.

[Description of Signs] 1 First sorting device 2 Friction charging device 3 Second sorting device 4 Hopper 5 Vibration device 6 Supply plate 7 Quantitative supply section 8 Drum electrode 9 Needle electrode 10 Plate electrode 11 Variable resistance 13 High voltage power supply device 14 Collection unit 15 Collection unit 16 Rotary brush 17 Static eliminator 19 Constant-quantity hopper 20 Input unit 21 Supply unit 22 Casing 23 Discharge unit 24 Microhole 25 Drive unit 26 Screw shaft 27 Stirring screw 27B Screw blade 28 Transfer screw 28A Screw blade 31 Opening / closing Member 32 Pivot member 33 Pressure load device 34 Discharge plate 35 Vibration device 36 Supply plate 37 Supply unit 38 Drum electrode 39 Plate electrode 40 High voltage power supply 41 Recovery unit 42 First recovery chamber 43 Second recovery chamber 44 Third recovery chamber 45 static eliminator 46 transport line 47 rotating brush 50 opening / closing member 5 Weight sensor 52 actuators 53 control system 54 the angle detection sensor 60 frictional charging device P plastic pieces M copper C stirring portion D transport unit H corona discharge field J sorting electrostatic field K sorting electrostatic field

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

[Procedure amendment 3]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Deleted

Continuation of the front page (72) Inventor Daisuke Tamakoshi 1-7-89 Minami Kohoku, Suminoe-ku, Osaka-shi, Osaka Inside Hitachi Zosen Corporation (72) Inventor Shogo Hamada 1-7-89 Minami-Kohoku, Suminoe-ku, Osaka-shi, Osaka No. F term in Hitachi Zosen Corporation (reference) 4D054 GA01 GA04 GA09 GB01 4F301 BF03 BF26 BF31 BG53

Claims (5)

[Claims] 1. A casing in which a plastic piece supply section is formed on the upstream side and a plastic piece discharge section is formed on the downstream side, and a plastic piece is rotatably arranged in the casing to form the plastic piece. A plastic friction charging device for frictionally charging a plurality of types of crushed plastic pieces provided with a stirring screw for stirring and frictionally charging, wherein the casing has an inner wall having a polygonal cylindrical cross section. A plastic triboelectric charging device characterized by being formed from a body. 2. A plastic triboelectric charging device according to claim 1, wherein said polygon is any one of a triangle to a dodecagon. 3. A conveying screw rotatably driven coaxially with the stirring screw is disposed upstream of the stirring screw, and a pitch a of a screw blade of the conveying screw and a pitch b of a screw blade of the stirring screw are arranged. In the range satisfying 1 <b / a ≦ 10, an opening / closing member is provided in the discharge section, and a pressure load device is provided so as to urge the opening / closing member in the closing movement direction. The plastic friction charging device according to claim 1 or 2, wherein: 4. A casing according to claim 1, wherein a plurality of minute holes are formed in a lower wall or a side wall of said casing.
A plastic triboelectric charging device according to any one of the above. 5. A corona discharge field formed between a drum electrode and a corona discharge electrode disposed opposite the drum electrode, wherein a mixture of a conductive material and a plastic piece supplied from a supply section is passed. A first sorting device that separates the conductive material and the plastic pieces into a collecting unit, and collects the conductive material and the plastic pieces in the collecting unit; a plastic friction charging device according to any one of claims 1 to 4; A second sorting device for passing the pieces through a sorting electrostatic field formed between the drum electrode and a counter electrode disposed opposite thereto to separate a plurality of types of plastic pieces and collect them in a collecting section. And the plastic triboelectric charging device is disposed below the first sorting device, and a plastic piece collection unit and a plastic friction charging device supply unit in the first sorting device are connected to each other; and With disposing the second sorting device below the plastic frictional charging device, milling waste sorting device characterized by being connected to the supply section of the discharge portion of the plastic frictional charging device second sorting device.