JP2001212518A - Method for separating plastics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separate chlorine-containing plastics from waste plastics. SOLUTION: A fluidized bed 5 has a flow straightening layer 6 which ejects a pulsating air flow 4 climbing up from below the lower face (a dispersing plate) of a fluidized bed of a tower 2 through the dispersing plate and regulates the velocity of an air flow in the tower 2. The waste plastics 8 dumped into the fluidized bed 5 from a loading opening 7 are separated/sorted out as the chlorine-containing plastics and non-chlorine-containing plastics by the ejection of the pulsating air flow 4. The precipitation velocity difference can be utilized to the maximum extent by adjusting the velocity wave-form of pulsation of the pulsating air flow 4 in an almost rectangular form and thus the separation efficiency is upgraded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the separation of plastics from general and industrial wastes, and mainly relates to chlorine-containing plastics (PVC) and polyvinyl chloride (PVC) from plastic mixtures discharged from waste and processing steps.
The present invention relates to a method for separating DC (polyvinylidene chloride) (hereinafter referred to as “chlorine-containing plastic”).

[0002]

2. Description of the Related Art Plastic wastes in general and industrial wastes (hereinafter referred to as "waste plastics") have the following problems in their treatment measures. (1) When heat treatment such as incineration is performed, chlorine-containing plastics are thermally decomposed to emit toxic hydrogen chloride gas. (2) In blowing into a blast furnace used as a reducing agent for an iron source, the permissible content of chlorine-containing plastic must be 1% or less. . (3) Landfill requires a large amount of land due to its large floor area ratio.

As methods for separating chlorine-containing plastics from mixed waste plastics, there are known wet separation methods such as sink floats, liquid cyclones, wet vertical separators, and centrifugal separators, and dry separation methods such as absorption of near-infrared rays and X-rays. Have been.

[0004]

However, in the wet separation method, PE (polyethylene) or PP (polypropylene) having a specific gravity lighter than water, PS (polystyrene) having a higher specific gravity than water, chlorine-containing plastic and chlorine-containing plastic (P
VC, PVDC), paper etc. can be separated, but chlorine-containing plastic (PVC,
It is not possible to separate PVDC) from paper. That is, in order to float and separate the PE, a heavy liquid having a specific gravity of about 1.2 must be used. For this reason, chlorine-containing plastics and paper are currently landfilled. Furthermore, it is impossible to separate PET (polyethylene terephthalate) having no specific gravity difference from chlorine-containing plastic. Furthermore, since a specific gravity liquid such as water is used for wet separation, there is a problem that wastewater treatment is indispensable, and the separated plastic needs to be dried.

[0005] On the other hand, in the case of dry separation, film-based plastics are difficult to align and have a problem of low throughput. In the conventional dry separation such as wind separation and vibrating sieve, it is possible to separate a large difference in specific gravity between plastic and metal.
There is a problem that it is difficult to separate materials having similar specific gravities such as, for example, chlorine-containing plastics and the like.

[0006] Further, there are many components having different specific gravity shapes in the plastic waste, and it is necessary to use a multi-stage apparatus in order to separate only a target component (for example, PVC) from these components.

Accordingly, an object of the present invention is to provide a plastic separation method capable of separating chlorine-containing plastics contained in waste plastics with high accuracy and high efficiency, and capable of separating various kinds of plastics. It is in.

[0008]

According to the first aspect of the present invention,
Injecting the rising air flow from the lower surface of the tower to form a fluidized bed of waste plastic in the tower, and pulsating the rising air flow to vibrate the waste plastic and remove the plastic mixed in the waste plastic In the method of separating the desired type, the pulsating velocity waveform of the pulsating ascending air flow is substantially rectangular.

The second aspect of the present invention is characterized in that the air flow rate and the flow velocity of the pulsating rising air flow and the number of times of pulsation can be adjusted.

An object of the present invention is to provide a separation method in which waste plastics contained in general and industrial wastes are previously crushed to an appropriate size or broken up by some method, and then a fluidized bed and an ascending pulsating air flow are combined. The problem is solved by changing the pulsation number of the ascending pulsation air flow over time or by making the velocity waveform when the pulsation number is fixed to a certain value approximate to a rectangle. That is, by making the velocity waveform not a sine curve but a substantially rectangular shape, the difference in sedimentation velocity can be used to the utmost, and plastics can be sorted by type. That is, not only chlorine-containing plastics but also various plastics can be separated for each material.

[0011] Multi-separation of plastics can also be performed by providing towers in multiple stages and providing outlets in each stage.

[0012] Also, by providing a plurality of separating means in series, it is possible to perform multiple kinds of separation.

[0013]

Next, an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment] FIG. 1 is an explanatory view showing a dry specific gravity shape separation apparatus according to an embodiment of the separation method of the present invention. FIG. 2 is a diagram showing waste plastic containing chlorine-containing plastic and non-chlorine-containing plastic. FIG. 3 is a graph showing a pulse interval, FIG. 4 is a graph showing a velocity waveform, and FIG. 5 is a dry specific gravity shape separation apparatus in which the diameter of a fluidized bed is changed in multiple stages. FIG.

The dry-type specific gravity shape separation apparatus 1 includes a tower 2 and a pulsation generator 3 for pulsating the rising air flow.

The tower 2 is provided with a fluidized bed lower surface (dispersion plate) on its floor surface, injects a pulsating air flow 4 rising from below the dispersion plate through the dispersion plate, and rectifies the air flow rate into the tower 2. A fluidized bed 5 having a layer 6 is constituted. In order to obtain a uniform flow rate in the fluidized bed 5, fine particles such as glass beads or a fine dispersion plate is used. The tower 2 is provided with a partitioning means such as a shutter-type valve or a partition plate for separating the separated waste plastics, and a plurality of outlets (not shown). The plastics separated by gas suction or the like are provided. Each can be taken out.

The pulsation generator 3 is provided with an electromagnetic valve (not shown) in the middle of the conduit from the blower, and opens and closes the electromagnetic valve to pass and cut off the air flow in the conduit so as to generate the pulsating air 4. It consists of a mechanism that generates. The pulsation cycle can be adjusted by controlling the opening and closing of the solenoid valve with a pulse transmitter or the like. Further, a pulsation generator 13 shown in FIG. 8 and used in a second embodiment described later can also be used. Waste plastic vibrates due to the pulsation of the air flow.

By injecting the pulsating air flow 4 from below to above the fluidized bed 5, the waste plastics 8 introduced into the fluidized bed 5 from the inlet 7 become layers due to their respective specific gravities. It is separated and sorted into plastic containing and non-chlorine containing plastic.

The air blowing flow rate and the flow velocity (0 to 20 m / s) when injecting the pulsating air flow 4 are adjusted to the separable speed of the chlorine-containing plastic, or are adjusted according to the type of plastic to be separated. Pulse number (0-10
000 pulses / min) can be appropriately adjusted, for example, at the intervals shown in FIG. 3 to improve the efficiency of separating waste plastics from chlorine-containing plastics (PVC, PVDC) and film-based plastics. At this time, by adjusting the velocity waveform to a substantially rectangular shape as shown in FIG. 4, the difference in sedimentation velocity can be used to the maximum,
Separation efficiency can be further improved.

Further, by appropriately adjusting the injection flow rate, the flow velocity, and the number of pulsations of the ascending air flow using such a velocity waveform, it is possible to realize classification of objects having relatively close specific gravity. For example, PE in mixed waste plastic
Plastics in the form of a film can be separated, such as separation of a film from a PVC film. In addition, other than plastic, it is possible to accurately separate a mixed metal copper wire and iron and aluminum, or a construction waste material such as earth and sand and cement.

Further, such a dry specific gravity shape separating apparatus 1
By providing a plurality of, it is possible to separate various kinds of plastic in waste plastic.

Also, as shown in FIG. 5, by changing the diameter of the fluidized bed 5 by changing the diameter of the tower 2 in multiple stages, the flow in each stage is also changed, so that multi-separation of plastics can be achieved. It is possible.

[Embodiment 2] Fig. 6 is an explanatory view showing a wind separation apparatus according to an embodiment of the separation method of the present invention, Fig. 7 is an explanatory view showing a pulsation generator, and Fig. 8 is waste plastic. FIG. 4 is an explanatory view showing an embodiment in which the plastics are sorted into a chlorine-containing plastic and a non-chlorine-containing plastic.

The wind separator 11 includes a wind separator 12 having a tower 12a and a pulsation generator 1 for pulsating an upward air flow.
3 is provided. The tower 12a injects the pulsating air flow 14 rising from the lower surface thereof, and forms a fluidized bed having a rectifying layer for rectifying the air flow velocity in the tower 12a.

As shown in FIG. 7, the pulsation generator 13
Piston 17 disposed in conduit 20 that branches off from conduit 16
, A rotating body 18 that rotates by power (not shown), and a link mechanism 19 including an arm that is pivotally mounted between the lower end of the piston 17 and the peripheral edge of the rotating body 18.
By transmitting the rotation of 8 to the reciprocating motion of the piston 17 by the link mechanism 19, the air flow from the blower 15 is pulsated. Also, as the pulsation generator 13, an electromagnetic valve (not shown) is provided in the middle of the conduit 16 from the blower 15 in place of the device shown in FIG. 7, and the electromagnetic valve in the conduit 16 is opened and closed by opening and closing the electromagnetic valve. A mechanism that generates a pulsation by controlling the passage and blocking of the air may be used. Either pulsation generator may be used. Waste plastic vibrates due to the pulsation of the air flow.

By injecting the pulsating air flow 14 from below to above the fluidized bed, the waste plastics 8 introduced into the fluidized bed from the inlet 20 are converted into chlorine-containing plastics 8a on the heavy material side of the fluidized bed, The non-chlorine-containing plastic 8b on the lightweight side is sorted out. The cycle of the pulsation can be adjusted by controlling the motor rotation speed of the power of the pulsation generator 13 with an inverter or the like, or by controlling the opening and closing of the solenoid valve with a pulse transmitter.

When the pulsating air flow 14 is injected upward from the bottom of the tower 12a, the flow rate and the flow rate (0
２０20 m / s) is adjusted to the separable speed of the chlorine-containing plastic, or adjusted according to the type of plastic to be separated, and the pulsation rate (0 to 10,000 pulses / min)
Is appropriately adjusted, for example, at intervals shown in FIG.
C, PVDC) and the separation efficiency of film-based plastics and the like can be improved. Then, by adjusting the velocity waveform to a substantially rectangular shape as shown in FIG. 4, the difference in sedimentation velocity can be used to the maximum, and the separation efficiency can be further improved.

Further, by appropriately adjusting the injection flow rate, the flow velocity, and the number of pulsations of the ascending air flow using such a velocity waveform, it is possible to realize classification of objects having relatively close specific gravity. For example, PE in mixed waste plastic
Plastics in the form of a film can be separated, such as separation of a film from a PVC film. In addition, other than plastic, it is possible to accurately separate a mixed metal copper wire and iron and aluminum, or a construction waste material such as earth and sand and cement.

Further, by providing a plurality of such wind separation devices 12, it is possible to separate various kinds of plastics from waste plastics.

[0030]

As described above, according to the present invention, the following useful effects can be obtained. The method of the present invention can be applied to both dry specific gravity shape separation and wind separation, and can separate chlorine-containing plastics from waste plastics with high efficiency, and can also perform various kinds of separation of plastics. Chlorine-containing plastic is removed from plastic waste in general and industrial wastes containing about 8% PVC, and a mixture mainly composed of plastic with a chlorine-containing plastic content of 0.4% or less can be obtained. Can be provided for reuse. The amount of waste landfilled can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a dry specific gravity shape separation device according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing an embodiment of the present invention for sorting waste plastic into chlorine-containing plastic and non-chlorine-containing plastic.

FIG. 3 is a graph showing pulse intervals according to the embodiment of the present invention.

FIG. 4 is a graph showing a velocity waveform according to the embodiment of the present invention.

FIG. 5 is an explanatory view showing a dry-type specific gravity shape separation device in which the diameter of the fluidized bed is changed in multiple stages according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a wind power sorting device according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a pulsation generator according to the embodiment of the present invention.

FIG. 8 is an explanatory diagram showing an embodiment of the present invention for sorting waste plastic into chlorine-containing plastic and non-chlorine-containing plastic.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dry-type specific gravity shape separation apparatus 2 Tower 3 Pulsation generator 4 Pulsation air flow 5 Fluidized bed 6 Rectification layer 7 Input port 8 Waste plastic 8a Chlorine-containing plastic 8b Non-chlorine-containing plastic 11 Wind separator 12 Wind separator 12a Tower 13 Pulsation generator Apparatus 14 Pulsating air flow 15 Blower 16 Conduit 17 Piston 18 Rotating body 19 Link mechanism 20 Conduit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigeki Yamazaki 1-2-1 Marunouchi, Chiyoda-ku, Tokyo F-term in Nihon Kokan Co., Ltd. 4D021 FA09 FA28 GA14 GA16 GA17 GA19 GA23 GA27 GB02 HA10 4F301 AA16 BA21 BF09 BF31

Claims (2)

[Claims] 1. A fluidized bed of waste plastic in the tower by injecting an ascending air flow from a lower surface of a tower, and pulsating the ascending air flow to vibrate the waste plastic to cause the waste plastic to vibrate. A method of separating plastics mixed in a desired type according to a desired type, wherein a pulsating velocity waveform of the pulsating rising air flow is substantially rectangular. 2. The method for separating plastics according to claim 1, wherein the air flow rate and the flow velocity of the pulsating rising air flow and the number of pulsations are adjustable.