JP2002254431A - Waste plastic recycling equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately and continuously separate plastic pieces of every kind into at least heavy plastic pieces and light plastic pieces to recover them. SOLUTION: The waste plastic recycling equipment 1 is constituted of a crusher 19 for waste plastics of every kind, and a centrifugal separator 30 receiving the supply of a mixture W6 from a mixing tank 21 receiving the supply of broken pieces to mix water or the like with the broken pieces and separating the mixture W6 into light plastic pieces PL and heavy plastic pieces PH. The centrifugal separator 30 is constituted so that the mixture W6 is supplied into a hollow rotary shaft to receive centrifugal force, and sent into the rotary cylinder provided around the rotary shaft in a relatively rotatably manner from the opening part of the intermediate part of the rotary shaft to further receive centrifugal force, and the light plastic pieces PL floating on the water held along the inner surface of the cylinder on the center side of the cylinder are separated from the outlet of one end part of the rotary shaft by the spiral body on one end side around the rotary shaft, while the heavy plastic pieces PH sunk in water are separated from the outlet of the other end part of the rotary shaft by the spiral body on the other end side of the rotary shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste plastic recycling system for collecting and sorting waste plastic into heavy and light plastic pieces.

[0002]

2. Description of the Related Art General waste such as garbage is discharged from general households, and from factories, business establishments and supermarkets, styrene foam materials, sheets, films,
A large amount of plastic is discharged in large quantities in the form of bags, bottles, etc., and these relatively thin-shaped waste plastic articles can be recycled as plastic raw materials,
It is processed into molded products such as rods and piles, and is used as a raw material for recycled solid fuel and recycled oil. In particular, the Packaging Recycling Law was enacted in 2000, and in order to promote the reuse of such resources, in recent years, plastic waste has been
It has been sorted out and collected in bulk.

[0003]

From the viewpoint of preventing dioxin contamination in the living environment, in order to recycle waste plastic as described above and convert it into a regenerated solid fuel, chlorine-containing resin, for example, from waste plastic material, It is necessary to remove polyvinyl chloride (PVC). Also, in order to reuse waste plastic as molding raw materials, it is necessary to classify as much as possible into each type of plastic, especially polyvinyl chloride and polyethylene, which are overwhelmingly used, are separately classified and separated. It is important to collect, and a recycling facility that can separate such plastics by type has been required.

[0004] The present invention has been proposed in view of the above, and is a recycling method capable of separating waste plastic discarded as general waste such as household waste or industrial waste into heavy plastic and light plastic to be recovered. Equipment is provided. Further, the present invention provides a waste plastic recycling facility capable of separating and collecting waste plastics, such as separating a chlorine-containing resin such as polyvinyl chloride, and operating continuously, and having improved separation accuracy. Things.

[0005]

SUMMARY OF THE INVENTION A waste plastic recycling apparatus according to the present invention comprises a crusher for crushing various kinds of waste plastic, and a mixing tank which receives waste plastic fragments and mixes the mixture with a liquid to form a mixture. And a centrifuge for separating the mixture supplied from the mixing tank into a light plastic piece and a heavy plastic piece by utilizing a specific gravity difference. The centrifugal separator has a rotating cylinder that provides outlets at both ends and rotates around a horizontal axis to apply a centrifugal force to the liquid along the inner surface of the cylinder.In the rotating cylinder, a rotating hollow shaft is provided. A rotating shaft composed of an opening for discharging the mixture into the rotating cylinder is inserted through a longitudinally intermediate portion of the hollow shaft, and the rotating shaft further has one end side and the other end of the rotating shaft in the rotating cylinder. A pair of helical bodies having helical directions opposite to each other on the rotation axis are mounted on the rotating shaft. In the centrifugal separator, the spiral body at the one end is formed by a light plastic piece floating on the liquid layer with its spiral edge located at an intermediate depth of the liquid layer along the inner surface of the rotary cylinder. The spiral body at the other end of the spiral body is discharged to the outlet side of the part side, and the spiral peripheral edge thereof is arranged close to the inner surface of the cylinder,
The heavy plastic pieces sinking into the liquid layer are sent to the outlet on the other end side and discharged, whereby the heavy plastic pieces and the light plastic pieces are separated.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the centrifugal separator of the present invention, a rotary cylinder is provided horizontally, and a centrifugal force is applied by rotation to the above-mentioned mixture supplied to the inside of the rotary cylinder, so that the mixture from the opening at the middle portion in the longitudinal direction to the surroundings. The rotary shaft of the hollow shaft to be fed into the rotary cylinder and the rotary shaft are provided so as to be able to rotate relative to each other horizontally around the rotary shaft. Is used to separate the light plastic piece on the center side floating in the liquid layer held along the inner surface and the heavy plastic piece on the inner surface side of the rotary cylinder sinking in the liquid layer. Inside the rotating cylinder, only the light plastic piece mounted around the one end side of the hollow rotating shaft and floating on the center side or with the liquid is separated from the outlet at the one end of the rotating cylinder. One-sided spiral body that reaches at least the middle depth of the liquid layer in the spiral direction. Furthermore, only the heavy plastic piece which is mounted around the other end side of the hollow rotary shaft inside the rotary cylinder and sinks on the inner surface side of the rotary cylinder, or together with the liquid, is provided at the other end of the rotary cylinder. The other end side spiral body having a spiral direction so as to be separated from the outlet and being close to the inner surface of the rotary cylinder is provided.

Thus, in the recycling facility of the present invention,
Heavy waste plastics and light waste plastics mixed with the waste plastic fragments crushed by the crusher are mixed with a liquid such as water in a mixing tank, and the mixture is stirred to remove adhering substances. It is fed to a centrifuge. In a centrifuge, the mixture is fed into a hollow rotary shaft and rotated.A centrifugal force is applied to eliminate the bubbles, eliminating the effects of bubbles and the like. First, it is separated into light plastic pieces floating on the shaft, and then continuously separated from the one end and the other end of the rotating cylinder by the spirals at one end and the other end of the hollow rotating shaft separately and accurately. The liquid is separated from the liquid or taken out together with the liquid. In the centrifugal separator of the present invention, by selecting the specific gravity of the liquid finely, the sorting of the waste plastic can be finely separated into many types by the difference in the specific gravity. In particular, water can be used as liquid, in which case heavy plastic pieces, such as polyvinyl chloride (PVC), having a specific gravity greater than 1.0 can be easily separated.

If the rotating cylinder of the centrifugal separator has cylindrical surfaces at both ends, each separated plastic piece is taken out together with the liquid, but separation from the liquid can be performed by a sieve in a later step. . By providing a tapered portion at one of the ends of the rotary cylinder, each plastic piece can be separated from the liquid and taken out as described later. For example, the rotating cylinder preferably has a tapered portion at the other end that spans the liquid layer on the inner surface side of the rotating cylinder and the air on the center side of the rotating cylinder. The helical body is arranged such that the helical periphery is close to the tapered inner surface of the tapered portion of the rotary cylinder, and separates the heavy plastic piece submerged in the liquid layer from the liquid layer, thereby forming the other end portion. Discharge from the outlet. Since the inner diameter of the tapered inner surface is reduced toward the other end,
Due to the action of the centrifugal force, the liquid layer can be prevented from flowing over the tapered surface to the outlet portion side, and only the heavy plastic pieces can be discharged from the outlet portion, separated from the liquid. The rotating cylinder on the one end side may have a cylindrical surface, or a tapered portion may be provided as in the other end side to make the inner surface tapered, thereby improving design selectivity.

It is preferable that the rotatable cylinder also has a tapered tapered portion at the one end, which straddles the liquid layer on the inner surface of the rotatable cylinder and the air on the center of the rotatable cylinder.
In this case, the one-end-side spiral has its spiral periphery reaching at least the intermediate depth of the liquid layer, and sends a light plastic piece to the one-end-side outlet to be discharged. Since this tapered surface blocks the flow of the liquid layer to the outlet,
A light plastic piece separated from the liquid is discharged from the outlet. The end of the rotary cylinder at the other end may have a cylindrical surface, but may have a tapered portion as described above.

In this way, in the centrifuge, heavy plastic and light plastic can be effectively separated by the difference in specific gravity or the difference in density with respect to the liquid. In particular, plastics to be classified can be appropriately changed by using liquids having different densities. The liquid can be water or a suitable aqueous solution, which separates a chlorine-containing resin heavier than water, for example, polyvinyl chloride, polychlorinated biphenyl, and a lighter plastic than water, for example, polyolefins, for example, polyethylene. can do. By separating a chlorine-containing material such as polyvinyl chloride pieces from waste plastic, there is an advantage that processing and supply can be performed without concern about generation of chlorine-based harmful gas upon reuse.

[0011] The crusher is used to reduce the waste to 50 to 200 mm.
A crusher for crushing coarse fragments into pieces having a size of
And a crusher for crushing into fine pieces having a size of １６16 mm. When the waste is further crushed into fine pieces of 10 to 16 mm by the crusher after crushing by the crusher, the overlap of the pieces in the centrifugal separator is reduced, and the specific gravity sorting action by the liquid layer is well received to promote the separation. Hard material removing means may be provided between the crusher and the crusher. This means for removing hard material includes a sieve for removing earth and sand, a magnetic separator for removing iron, aluminum and copper,
When a non-magnetic metal sorter that removes non-magnetic metals such as brass and stainless steel is included, the earth and sand is removed before crushing by a sieving machine to prevent wear of the crusher mainly by shearing Further, useful iron and non-magnetic metal can be recovered by a magnetic separator and a non-magnetic metal sorter.

[0012] In the centrifugal separator, it is preferable to provide a mixture supply section which is communicated via a rotary joint at one end of the rotary shaft inside the hollow of the rotary shaft. The mixture is continuously supplied from the mixture supply section into the hollow interior of the rotating shaft. Furthermore, it is preferable that a stationary housing that covers the rotary cylinder is disposed, and the housing has a structure having a partition that covers the outlet on the one end side and the outlet on the other end side. In this case, light plastic pieces and heavy plastic pieces coming out of the respective outlets at both ends of the rotary cylinder can be captured in each partition of the housing without being scattered.

[0013] Further, the centrifugal separator includes a drive unit for separately rotating and driving the rotary shaft and the rotary cylinder so that a relative speed difference between the rotary shaft and the spiral body and the rotary cylinder can be adjusted. The time during which the mixture supplied to the inside of the rotating cylinder stays inside the rotating cylinder so that the mixture supplied to the inside of the rotating cylinder is effectively separated into a light plastic piece and a heavy plastic piece by a specific gravity difference with the liquid. Can be adjusted by setting the relative speed difference.

Further, the centrifugal separator preferably uses water as a liquid and is combined with a hydrocyclone. A heavy plastic piece supplied from the centrifugal separator is mixed with water and supplied to the hydrocyclone. Further, heavy and heavy plastic pieces are separated into the vortex descending flow from the hydrocyclone and light plastic pieces during the overflow.
This allows the mixture to be separated into three different gravitational density groups of plastic pieces using the same water as the working liquid.

[0015] The recycling facility may further include a dryer and a solid former. The dryer receives the supply of light plastic from the centrifugal separator, and after drying, feeds the solid former to the solid former. Can be supplied. The dryer receives the supply of light plastic from the centrifugal separator, and after drying, supplies the plastic to the solid former. Polyvinyl chloride containing chlorine in advance (specific gravity of about 1.16 to 1.7
If heavy plastic pieces such as 0) are excluded, light plastic pieces such as polyethylene (specific gravity of about 0.93 to 0.95) can be removed with a dryer to remove moisture that adversely affects solidification. It can be processed into a solid such as a solid fuel that does not generate dioxin by a solid forming machine. A pellet mill, a granulator, or an extruder can be used as the solid forming machine.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a waste plastic recycling system according to the present invention.

Details of the centrifuge are shown in FIGS.
Referring to FIG. 1, the centrifugal separator 30 includes a rotating cylinder 35 that rotates around a horizontal axis thereof. In this example, the rotating cylinder 35 rotates from a substantially central portion to one end. A cylindrical portion 35A having a cylindrical inner peripheral surface as a cylindrical surface is provided. On the inner periphery of the cylindrical portion 35A, a liquid retaining weir 35E having an inner flange shape is formed in order to form a liquid layer by centrifugal force on the inner peripheral surface of the rotary cylinder.
Is provided. In this example, the rotary cylinder 35 has a tapered portion 35B having a tapered inner peripheral surface on the other end side. The rotating cylinder has a light plastic piece outlet 35L at the end of the cylindrical portion 35A on the one end side, a heavy plastic piece outlet 35H at the end of the tapered portion 35B, and a part of the peripheral wall of the cylinder. Is formed as an opening that opens.

A rotary shaft 37 is inserted into the rotary cylinder 35, and the rotary shaft 37 is hollow, and a pair of the helical bodies 3 is provided.
An opening 31M is provided between 6A and 36B so that the rotating shaft 3
7, the mixture supply pipe 31 communicates with the inside of the rotating cylinder 35 from the hollow part, and the mixture supply pipe 31 is disposed in the hollow part of the rotation shaft 37 so as to penetrate the bearing part on one end side, and one end of the mixture supply pipe 31 is open. The other end thereof is disposed near the portion 31M, and the other end thereof communicates with the mixture supply portion 33 via the rotary joint 32 at the right end of the rotary shaft 37. The mixture of the plastic piece and the liquid supplied from the mixture supply section 33 passes through the mixture supply pipe 31 and moves from one end to the opening 31M via the hollow portion of the rotating shaft 37, and the mixture further passes through the opening 31M. From between the pair of spirals 36A, 36B and discharged into the rotating cylinder 35, the discharged mixture is subjected to centrifugal force due to the high-speed rotation of the rotating cylinder 35, and on the inner peripheral surface of the rotating cylinder 35, It is kept in layers.

Further, the rotating shaft 37 has a pair of spiral bodies 36A, 36B which are spirally opposite to each other inside the rotating cylinder.
Are coaxially fixed around the rotation axis and rotate with the rotation of the rotation axis 37. The helical body 36A and the helical body 36B on the rotation axis are disposed on the cylindrical portion 35A on one end side and the tapered portion 35B on the other end side, and in the rotation direction, the light plastic piece PL and the heavy plastic piece PH are respectively separated. , Are arranged so as to feed in the directions of the corresponding outlets 35L, 35H. The helical body 36A for feeding the light plastic piece at the one end has an outer diameter such that the helical rim of the cylindrical portion 35A enters the middle portion of the liquid layer. Helical body 36B for heavy plastic piece on the other end side
Has an outer diameter close to the inner surface of the tapered portion 35B.

Further, the housing 39 has internal compartments 39A and 39B corresponding to the outlets 35L and 35H of the rotary cylinder 35, and a light plastic outlet 39L and a heavy plastic outlet 39L are provided below the respective internal compartments. Exit 3
9H and collect. Rotating cylinder 35 and rotating shaft 37
The scroll composed of the spiral 36 and the scroll 36 is separately driven to rotate by the pulleys 38A and 38B at the left end.
The rotating cylinder 35 is rotated at a high speed so that at least the mixture supplied to the inner peripheral surface can be held in a layered form along the inner peripheral surface of the rotating cylinder 35 by centrifugal force. The rotation of the other rotating shaft 37 and the helical bodies 36A and 36B is performed by
By the relative rotation with respect to the inner surface of the rotary cylinder, the plastic pieces are rotationally driven at a relative speed such that the plastic pieces are sent to the ends.

At this time, the rotary cylinder 35 and the spiral bodies 36A, 36
B is driven to rotate by setting a rotation speed difference, and is generally driven to rotate so that the rotation speed of the scroll including the spirals 36A and 36B is higher than that of the rotation tube 35. The rotation speeds of the spirals 36A and 36B are as follows: heavy plastic PH1 and light plastic PL.
It can be set so as to adjust the residence time of the mixture W6 in the rotary cylinder 35 while observing the separation accuracy with respect to 1.

The heavy plastic piece PH1 is made of a spiral 36
The liquid is sent to the tapered portion 35B by B and is moved toward the heavy plastic outlet portion 35H while being separated from the liquid by the drainage action of the tapered portion 35B, and is discharged from the outlet portion 35H. The other light waste plastic strip PL1
Is suspended in the liquid layer, is moved to the one end side by the spiral body 36A of the cylindrical portion 35A, and is moved toward the light plastic outlet portion 35L, and the outlet portion 35L
Is discharged together with the liquid W. The other end of the rotary cylinder 35 may be formed into a cylindrical surface without providing the tapered portion 35B, and the heavy plastic piece PH and the light plastic piece PL together with the liquid WT from the corresponding outlet portions 35L and 35H, respectively. Are separated.

FIG. 2 shows a modification of the centrifugal separator shown in FIG. 1. In this example, a tapered member is also arranged at one end of the rotary cylinder so that a light plastic piece can be removed from liquid or water. The difference is that an internal structure is also provided for separation. In this example, a tapered member 35C fixed to the end side of the cylindrical portion 35A on the one end side is disposed between the cylindrical portion 35A and the rotating shaft 37. The tapered member 35C has its enlarged end held at an intermediate position of the liquid layer W, and the reduced-diameter end of the tapered member 35C is fixed to one end of the rotary cylinder 35. And rotate together. Further, the inner circumference of the end portion on the reduced diameter side of the tapered member 35C is
5 is connected to a light plastic outlet 35L provided at one end, and the helical periphery of the helical body 36A at the one end side is disposed close to the inner peripheral surface of the tapered member 35C. The light plastic piece floating in the liquid layer W is swept up to the inside front side of the tapered member 35C by the helical periphery of the spiral body 36A at one end side, separated from the liquid layer, and discharged from the outlet 35L.

In this structure, a narrow disk space 35F for collecting water is formed coaxially at the end of the cylindrical portion 35A of the cylindrical body 35 in order to discharge only the liquid layer. The circumferential portion of the disc-shaped space communicates with the space between the end on the reduced diameter side and the end of the rotary cylinder, and the center axis side of the cylindrical space 35F is a bearing portion on one end side. Thus, it is connected to the liquid outlet 34 through a gap between the outer periphery of the rotating shaft 37 and the inner periphery of the shaft support of the cylindrical portion 35A. As a result, the liquid obtained by separating a light plastic piece from the liquid outlet portion 34 at the end of the cylindrical portion 35A passes through the gap between the disk-shaped space 35F and the bearing portion and the liquid outlet portion 3
4 and discharged.

FIGS. 3 to 5 show examples of waste plastic recycling equipment utilizing the above-described centrifugal separator.
Waste W containing various kinds of accumulated waste plastic and shredder dust is crushed from an input device such as a shovel loader through a quantitative feeder such as a screw feeder.
0 where it is crushed into coarse pieces of approximately 50-200 mm.

The debris W1 is removed from the sediment Z1 by a sieving machine 13 such as a vibrating sieve, a rotary disk separator (a miracle separator) or a wind separator. In the case of wastes such as pipes, cans, bricks, etc., which have a large amount of foreign matter, a rotary disc separator can be used, and a plurality of rotating rotors in which large-diameter rings and small-diameter rings are alternately arranged in the axial direction are connected to adjacent rotors. The large-diameter annular body and the small-diameter annular body are arranged on an inclined frame so as to form a sieve spacing.
1 and the repellents roll down and are separated. In the case of waste that is a lot of waste plastic and is relatively well sorted in advance, a vibrating screen, a wind separator, and a horizontal rotary disk separator are preferable.

The wind separator comprises a hopper to which the fragments W13 are supplied from above by a conveyor or the like, a horizontal supply means for supplying a constant amount of the fragments W1 from the hopper to an intermediate portion of a vertical vertical separation tube, and a vertical separation device. A vertical cyclone housing having a suction blower communicating with the upper end of the pipe at the upper end and generating a negative pressure therein.

The opening at the lower end of the vertical separation tube is used as an air suction port of a suction blower to generate a rising air flow in the vertical separation tube, to drop the soil Z1 by its own weight and to vertically move the lightweight debris W2 by the air flow. It is transported and separated into the cyclone housing, the lower end opening is used as an outlet for soil and sand Z1, and the lower end of the cyclone housing is provided with a rotary seal valve for taking out lightweight debris W2. The vertical separation tube can be installed not only vertically but also in an inclined state, and forms a relatively long sliding fall path as a zigzag bent portion downward, and the earth and sand Z1 and the debris W2 move along the sliding fall path. It is configured to separate well during

The vertical cyclone housing is composed of a cylindrical portion provided with a suction blower on the top end surface and an inverted conical portion provided with a rotary seal valve for taking out the lightweight debris W2 at the lower end portion. It is fixed at. The vertical separation pipe communicates in a tangential direction at the upper end of the vertical cyclone housing so that the separated and conveyed lightweight debris W2 spirally falls in the housing. As a suction blower, a roots blower or the like, which is driven by a variable speed electric motor controlled by an inverter and has a large air volume, is used, and a bag filter is provided at an exhaust port thereof for collecting suspended matter. The suction blower generates a constant negative pressure for separating light-weight materials in the middle of the supply of the vertical separation tube, and the constant negative pressure is maintained by a quantitative supply using a vibratory feeder or the like.

Many crushers 10 have been proposed today. A general crusher 10 will be briefly described. A motor and a speed reducer are arranged so as to bite into a working chamber inside a casing below a hopper from top to bottom. Two crushing screws, which are driven at high speed, are horizontally supported, and crush large-sized waste such as containers and various containers and discharge it from below through a coarse screen. By this crushing, metals, plastics, woods, and the like are separated from the composite material product, thereby facilitating the sorting by a magnetic separator or a non-magnetic metal sorter. On the outer peripheral edge of the crushing screw, protruding blades of various shapes for promoting biting of the crushed material can be appropriately provided.

Another example of the crusher 10 is a hopper with an inclined side plate which has a bag breaking function when the waste W is wrapped in a bag or a container and forms a processing space narrowed downward. A rotor composed of a rotor rotatably driven in a casing and a plurality of sets of blades arranged in the longitudinal direction of the rotor is used, and the screw type is used as a secondary crusher before the primary crusher. Can be installed as The rotor is supported by bearings on the center of the upper partition plate, which traverses between the shelving blades. Below the upper partition plate, there is provided a lower partition plate in which a plurality of longitudinal members of fixed blades are fixed on an arc surface to form a rough screen.

In addition, a conventional hammer crusher or rotary press crusher is appropriately selected and used as a crusher according to a large amount of contaminants in the waste. The screw crusher is also available in two-shaft and single-shaft types, with a rotating tapered crushing screw part, a straight crushing screw part and a plurality of longitudinal fixed blades on the inner surface of the casing and a ring-shaped fixed blade between the tapered part and the straight part. The crushing can be performed between the crushed pieces, and the crushed pieces can be crushed to a size that can eliminate the crushing.

Fragments W2 that have been crushed and debris Z1 have been removed
From there, a magnetic substance Z2 such as iron is removed by a magnetic force sorter 15 composed of a disc-shaped or comb-shaped electric magnet suspended on a cooler. Further, the fragment W3 from which the magnetic substance Z2 has been removed
The non-magnetic metal Z3, for example, aluminum, copper, brass, stainless steel, etc. is removed by the non-magnetic metal sorter 17 which repels using a rotating magnetic field. The debris W4 from which the soil Z1, the magnetic substance Z2, and the non-magnetic metals Z3 have been removed is supplied to the crusher 19. The non-magnetic metal sorter 17 is a permanent magnet type drum rotating type non-magnetic metal separator, and the introduced non-magnetic metal is a good conductor and generates an eddy current by causing an electromagnetic induction phenomenon by lines of magnetic force, The non-magnetic metal Z3 receives a strong AC magnetic field and is repelled by the eddy current generated inside the non-magnetic metal by the high-speed rotating drum having the permanent magnet. In that case,
The degree of repelling differs depending on the type of non-magnetic metal.

Although many pulverizers 19 have been proposed today, a general pulverizer 19 will be briefly described. In the case of a two-shaft shearing type, a roughly crushed fragment W4 of a certain size is used.
In the casing, a pair of left and right upper and lower crushing blades are shredded by a protruding blade of a mating shaft and a corresponding vertical fixed blade forming a screen. The screen has a desired size, for example, 10 to 16 mm. Degree of fragments W5 are obtained. As the crusher 19, besides the two-shaft shear type, a single-shaft cutter type is also used. A plurality of rotary crushing blades and fixed blades are alternately arranged in a working chamber inside the casing below the hopper, and the crushed material is shredded between them.

At the bottom, it is spaced in the width direction of the transverse support plate,
A screen made up of a plurality of vertical fixed blade members forming a finer lattice shape is attached, and fragments having a desired size are obtained by the screen. The rotary crushing blade is attached to a rotating shaft supported by a bearing at the center of the fixed blade with a phase sequentially shifted in a rotating direction. A short fixed blade is also provided on the edge side of the rotary crushing blade. In addition, as the pulverizer 19, there is a rotary press crusher of a biaxial type or a uniaxial type. Can be crushed between the ring-shaped fixed blades.

The fine fragments W5 crushed by removing the hard material are then sent to the mixing tank 21 by a predetermined amount by a quantitative feeder 19A equipped with a stirrer, and mixed with the water of the separation working liquid. The mixing tank 21 is provided with a screw stirrer 22 for uniformly mixing the small pieces W5 and separating the deposits from the small pieces W5 by the stirring action. Mixing tank 21
Is supplied with tap water Y1 from the water supply device 20, and always keeps a substantially constant level of water as the working liquid WT.

The mixture W6 of the strip W5 and the water WT is supplied from the mixing tank 21 to the centrifugal separator 30 by the pump 23. As shown in FIG. 2, for example, the centrifugal separator 30 preferably separates the light plastic piece PL and the heavy plastic piece PH from the liquid and separates them. The liquid is separately taken out.

As shown in FIG. 2, the mixture W6 is passed through a hollow rotary shaft 37 to a mixture outlet 31 at the center in the longitudinal direction.
M is supplied to the inside of the rotary cylinder 35, and the centrifugal force is applied by the rotation to remove air bubbles and float on the water held along the inner surface of the rotary cylinder 35.
(For example, polyethylene: specific gravity 0.94) and heavy waste plastic PH1 (for example, polyvinyl chloride: specific gravity 1.3 or nylon polyamide resin) on the inner surface side of the rotary cylinder submerged in water:
The specific gravity 1.1) is separated by a spiral body 36 mounted around a rotation axis 37. This embodiment does not use an alkaline aqueous solution such as caustic soda, facilitates liquid management, and causes little damage to equipment.

The mixture W6 of the strip W5 and the water WT is passed from the mixing tank 21 to the inside of the centrifuge 30 by the pump 23 through the hollow rotary shaft 37 through the rotary joint 32 at the right end, from the opening 31M at the center thereof. It is supplied to the inside of the rotating cylinder 35. The mixture W6 is applied with a centrifugal force by rotation inside the rotary cylinder 35 to remove bubbles. Liquid WT, for example
The plastic pieces PH that are heavier than the liquid layer W according to the specific gravity difference with respect to water sink into the inner surface of the rotary cylinder 35, and the plastic pieces PL that are lighter than the liquid layer move toward the air around the rotation shaft 37 near the center. float.

If the heavy plastic piece PH separated from the centrifuge 30 is further mixed with two types of heavy plastic pieces having a specific gravity of more than 1, such as polyethylene terephthalate (PET) and polystyrene (PS), They are also mixed with water as the working liquid, and the hydrocyclones 70 cause relatively heavy P
ET and relatively light PS can be separated by overflow. The separated heavy plastic pieces PH are treated with chlorine-containing substances as described below, and the separated light plastic pieces PL are dried by a dehydrator or a dryer 64 to form a solid molding machine 65 as described later. ~ 67. The separated water WT is collected in a return tank 72 after being filtered by a strainer 71 and then returned to the mixing tank 21 by a pump.

If many kinds of heavy plastic pieces are further mixed with the separated heavy plastic pieces PH, a centrifuge is provided as shown in FIG. It is configured to use the working liquid whose specific gravity is sequentially increased from 1.0. When the second centrifugal separator 50 is provided, the heavy plastic piece PH1 (mixture W7 of polyvinyl chloride and polyamide resin having a specific gravity greater than 1) from the first centrifugal separator 30 is passed through the centrifugal dehydrator 41 or the like. After being dehydrated, it is supplied to the heavy liquid tank 43 of the specific gravity adjusting tank and mixed with the heavy liquid Y2 having a specific gravity larger than that of water. The heavy liquid tank 43 is supplied with the heavy liquid Y2 from the heavy liquid tank 43A by the heavy liquid supply device 43B.

The mixture W7 is pumped from the heavy liquid tank 43 by a pump.
Is supplied to the second centrifuge 50. The second centrifuge 50 has the same structure as the first centrifuge 30, and instead of water, heavy liquid such as salt water (maximum specific gravity of about 1.
(4) is used for the separation of the specific gravity of waste plastic (for example, the specific gravity of heavy liquid is 1.
The specific gravity is set to 1.2, which is slightly smaller than 3 and slightly larger than the specific gravity 1.1 of the polyamide resin). The mixture W7 is
Heavy plastic pieces PH2 by the second centrifuge 50
(Polyvinyl chloride) and a light plastic piece PL2 (polyamide resin), and the heavy liquid is returned to the heavy liquid tank 43A by a pump.

Heavy plastic pieces of polyvinyl chloride PH
2 is supplied to a desalter 61 and heated to remove chlorine as chlorine vapor X1. The chlorine vapor X1 is supplied to the cooler 6
The mixture is cooled and condensed in step 2, absorbed in water and recovered as hydrochloric acid X2. Alternatively, chlorine vapor or chlorine gas can be absorbed by quick lime in a chlorine gas absorbing device. The desalted waste plastic piece W8 is formed into a plastic solid X3 by the granulator 65. On the other hand, the light waste plastics PL1, PL from the first and second centrifuges 30, 50
2 is supplied to a dryer 63, and after drying, is supplied to a solid forming machine such as a pellet mill 66, a granulator 65, and an extruder 67, where a solid fuel, an oily raw material, a blast furnace reducing material, It is formed into a solid X4 usable for coke oven fuel. The solid matter from the extruder 67 is further recycled in a re-pellet mill 68 as recycled plastic pellets X5.

The pellet mill 66 is supplied with dry, strip-shaped light plastic from an opening into a ring of a horizontally rotating cylindrical body which is rotatably supported and rotatably supported in a horizontal state. In the ring, the rolling wheels of the two pushing rollers pressed against the inner surface of the ring are rolled in the directions indicated by arrows, and the mixture is collected in the space behind the rolling direction and compressed by the rolling wheels to form a peripheral wall of the ring. The die to be formed, for example, diameter 5
It is compacted and extruded from many die holes of mm. 5-
After being extruded about 7 mm, the ring is cut by a cutter blade provided outside the ring to obtain a granular solid. Numerous grooves are formed on the outer peripheral surface of the rolling wheel in order to prevent slippage of the strip and facilitate the stripping. The granular solids are fed to a cylindrical sieving machine by a conveyor to sieve and sort and remove what has collapsed when cut by a cutter blade, and the granular solids with good shape retention are sent to a cooler. Air cooling is preferred.

The granulator 65 will be briefly described. The crushing, kneading, compression and pulverization are performed while conveying a light-weight material containing plastic put in from an inlet at one end to a take-out at the other end in a longitudinal direction. , Which raises the temperature by the heat of friction and compression and melts the plastic, a pair of rotating shafts arranged in the elongated casing in a longitudinal direction and driven to rotate in opposite directions, and a spiral body attached to each of them. It comprises a pressed body, an abrasion-resistant lining body detachably provided in the casing with a predetermined gap therebetween, and a perforated plate with a nozzle for solidification at an outlet. The pressed body constitutes, in particular, a mortar-shaped pressed part which promotes pulverization and dissolution. As another granulator, a rubbed plate granulator that moves like rolling a dumpling with the palm is also used.

[0046]

According to the centrifugal separator of the waste plastic recycling equipment of the present invention, a heavy plastic piece sinking in the liquid layer and a light plastic piece floating in the liquid layer are first separated in the rotary cylinder, and then the hollow rotary shaft is rotated. The helical members on one end side and the other end side can separate and discharge separately and accurately from one and the other outlets at both ends of the rotary cylinder. By selecting the specific gravity of the liquid forming the liquid layer and preparing it as a heavy liquid, the sorting of waste plastic can be separated into many types more finely compared to the specific gravity of the heavy liquid,
If the liquid is water, it can be effectively divided into lighter and heavier plastic pieces than water. Furthermore, if the rotary cylinder has a cylindrical surface, each plastic piece can be taken out together with the liquid.

If the rotary cylinder is provided with a tapered portion on the other end side and the spiral periphery of the other end side spiral body is arranged close to the inner surface of the tapered portion, from the outlet on the tapered portion side, Heavy plastic pieces with little liquid adhesion can be removed.

If the rotary cylinder is provided with a tapered portion at one end and the spiral at one end is arranged so as to reach at least the intermediate depth of the liquid, almost no liquid adheres from the outlet on the tapered portion side. Light plastic pieces can be efficiently removed.

The crusher includes a crusher and a crusher, and if a hard material removing means is provided between the crusher and the crusher, the waste is crushed into fine pieces. The overlap of the fragments at the step is reduced, and the separation is promoted by the specific gravity sorting action by the liquid. In addition, by the hard material removing means, it is possible to prevent wear of the crusher mainly by shearing by removing earth and sand, and steel scrap including useful stainless steel,
Metal scraps of non-magnetic metals can be collected.

Further, the centrifugal separator is provided with a mixture supply section connected through a rotary joint so that the mixture can be continuously supplied from the mixture supply section to the hollow interior of the rotating shaft without causing liquid leakage. If a fixed housing is provided to cover the rotary cylinder, on the take-out side, light plastic pieces and heavy plastic pieces released from the respective outlets at both ends of the rotary cylinder can be captured in each partition of the housing without scattering. Can be.

Further, the centrifugal separator has a drive unit for separately rotating and driving the rotating shaft and the rotating cylinder so that a relative speed difference between the rotating shaft and the spiral body and the rotating cylinder can be adjusted. If it is provided, the time during which the waste plastic stays inside the rotary cylinder can be adjusted by setting the relative speed difference, whereby the specific gravity difference effectively separates the light plastic piece and the heavy plastic piece. it can.

Further, the centrifugal separator uses water as a liquid, and furthermore, if a hydrocyclone is used, the same water is used as a working liquid to separate the mixture into three types of plastic pieces of a specific gravity difference group. it can.

The recycling equipment of the present invention can further include a dryer and a solid forming machine such as a pellet mill, a granulator, an extruder, etc., and after the light plastic from the centrifugal separator is dried by the dryer, the solid is formed. It can be solidified by a material forming machine, and if it is solidified without heavy plastic pieces such as polyvinyl chloride containing chlorine, it can be processed into solids such as solid fuels that do not generate dioxins during use. be able to.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a centrifugal separator of a recycling facility according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a centrifugal separator according to another embodiment of the recycling facility according to the embodiment of the present invention.

FIG. 3 is a flowchart showing a recycling facility according to an embodiment of the present invention.

FIG. 4 is a flowchart showing an operation process using a waste plastic recycling facility according to an embodiment of the present invention.

FIG. 5 is a flowchart showing an operation process using a waste plastic recycling facility according to another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 Waste plastic recycling equipment 10 Crusher (coarse crusher) 13 Hard material removing means (sieving machine) 15 Hard material removing means (magnetic separator) 17 Hard material removing means (non-magnetic metal sorter) 19 Crusher (crusher) 21) Mixing tank 23 Pump 30 First centrifugal separator 31 Rotating shaft 31A Hollow passage 31M mixture outlet 32 Rotary joint 33 Mixture supply unit 34 Liquid outlet 35 Rotating cylinder 35A cylindrical part 35B conical part 35H Heavy waste plastic outlet 35L Light waste plastic outlet 36 Helical body 39 Housing 41 Dehydrator 43 Heavy liquid tank 50 Second centrifuge 61 Desalination means 63 Dryer 65 Solid material forming machine (granulator) 66 Solid material forming machine (pellet mill) 67 Solid matter Forming machine (extruder) PH Heavy waste plastic PL Light waste plastic W Including waste plastic Wastes

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) B03B 7/00 B03B 7/00 B04B 1/20 B04B 1/20 F term (reference) 4D057 AA09 AB01 AC01 AC06 AE03 AF05 BC16 4D065 CA12 CB02 CC01 EB14 ED23 ED45 4D067 DD02 DD06 EE14 EE16 GA16 4D071 AA53 AB06 CA03 CA05 DA15 4F301 AA11 AA21 BA21 BF03 BF09 BF31

Claims (8)

[Claims] 1. A crusher for crushing various kinds of waste plastics, a mixing tank receiving a supply of pieces of waste plastics and mixing a liquid to form a mixture, and a light plastic from the mixture supplied from the mixing tank. A centrifugal separator that separates the pieces into heavy pieces and plastic pieces, wherein the centrifuge provides outlets at both ends of the cylinder and rotates about a horizontal axis to form a liquid layer on the inner surface of the rotating cylinder. A rotary cylinder that applies a centrifugal force to the mixture, a hollow shaft that is inserted into and rotates in the rotary cylinder, and an opening that discharges the mixture into the rotary cylinder at a longitudinally intermediate portion of the hollow shaft. A pair of helical bodies having opposite helical directions and mounted on the rotating shaft while being divided into one end side and the other end side of the rotating shaft in the rotating cylinder, Wherein the spiral body at one end is the spiral body The edge is located at an intermediate depth of the liquid layer along the inner surface of the rotary cylinder, and a light plastic piece floating in the liquid layer is sent to the outlet at the one end side and discharged, and the spiral body at the other end side is formed by a spiral peripheral edge thereof. Is disposed close to the inner surface of the cylinder so that heavy plastic pieces sinking in the liquid layer are sent to the outlet on the other end side and discharged therefrom. 2. The rotating cylinder has a tapered portion at the other end that spans the liquid layer on the inner surface of the cylinder and air on the center side of the rotating cylinder, and the other end-side helical member has the tapered portion. 2. The recycling facility according to claim 1, wherein a heavy plastic piece is separated from the liquid layer and discharged from an outlet at the other end in the vicinity of the inner surface of the liquid. 3. The rotating cylinder has a tapered portion on one end side that spans a liquid layer on the inner surface side of the cylinder and air on the center side of the rotating cylinder, and the one end side spiral body has a spiral peripheral edge. The recycling facility according to claim 1 or 2, wherein the plastics reaches at least the intermediate depth of the liquid layer and sends the light plastic pieces to the outlet on the one end side for discharge. 4. The crusher according to claim 1, wherein the crusher removes the waste from 50 to 200.
and a crusher for further crushing the coarse pieces into fine pieces having a size of 10 to 16 mm, wherein a hard material removing means is provided between the crusher and the crusher. The hard material removing means provided includes a sieving machine for removing earth and sand, a magnetic separator for removing iron waste, and a non-magnetic metal sorter for removing non-magnetic metal waste. The recycling equipment described in. 5. The centrifugal separator according to claim 1, further comprising: a mixture supply unit that communicates with a hollow interior of the rotary shaft through a rotary joint at one end of the rotary shaft; and a fixed housing that covers the rotary cylinder. And a partition portion for covering each outlet portion.
4. The recycling facility according to any one of to 3 above. 6. The centrifuge according to claim 1, further comprising a drive unit for individually rotating the rotating shaft and the rotating cylinder so that the relative speed between the rotating shaft and the spiral body and the rotating cylinder can be adjusted. 4. The recycling facility according to any one of to 3 above. 7. The method according to claim 7, wherein the liquid is water, and the recycling equipment mixes the heavy plastic pieces supplied from the centrifuge with the water to mix the heavy plastic pieces during the vortex downflow and the light plastic pieces during the overflow. The recycling facility according to any one of claims 1 to 3, further comprising a hydrocyclone that is further separated from the recycling equipment. 8. A dryer for drying the light plastic pieces supplied from the centrifuge, wherein the recycling equipment comprises:
The recycling facility according to any one of claims 1 to 3, further comprising a solid material forming machine that solidifies the light plastic pieces after drying.