JPH0663943A - Apparatus for separating and recovering waste plastic - Google Patents

Abstract

PURPOSE:To efficiently recover waste plastic in a high yield by a method wherein a vertical cylindrical body equipped with a screw is arranged in the liquid received in a charging tank and water streams forcibly dispersing plastic pieces are generated by the screw to transfer the dispersed pieces to a separation tank. CONSTITUTION:A screw 3 is positioned in a vertical cylindrical body 4 and rotationally driven by a motor 7 through the shaft 6 having the screw 3 connected thereto. Falling streams are generated in the vertical cylindrical body 4 by the rotation of the screw 3 and plastic pieces are drawn into the vertical cylindrical body 4 by the falling streams to be forcibly dispersed and the dispersed pieces are transferred to a separation tank within a short time. In the separation tank 2 almost generating no flow, waste plastic is separated into low specific gravity matter 8 such as polyethylene and high specific gravity matter 9 such as polyvinyl chloride according to specific gravity difference. The low specific gravity matter 8 floats on the surface of the separation tank 2 and the high specific gravity matter is sedimented on the bottom part of the separation tank 2. The precipitate of the high specific gravity matter 9 is sent to a circulating passage 3 equipped with an air lift 10 and a recovery device 11 to be recovered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention separates a mixture of various waste plastics into a high specific gravity material and a low specific gravity material by utilizing the difference in specific gravity in a liquid, and recovers the waste plastics separately. It relates to the device.

[0002]

2. Description of the Related Art Conventionally, there is an apparatus for separating and recovering waste plastics utilizing the difference in specific gravity as shown in FIG.

This apparatus mainly comprises an input tank (21), a separation tank (22) and an intermediate tank (23) between them. In the charging tank (21) and the intermediate tank (23), a circulating flow is generated in water or salt water by blowing air from the tank bottom, and the mixture of waste plastics charged in the charging tank (21) is charged in the charging tank.
During the transfer from (21) to the intermediate tank (23), it is dispersed by the circulation flow, and when it moves to the separation tank (22) where there is almost no flow, low specific gravity (24 ) And a high specific gravity substance (25) such as polyvinyl chloride. Floating low specific gravity (24) is a separation tank as it is
The high specific gravity material (25) taken out from the (22) and deposited on the bottom of the separation tank (22) is sent to a circulation path (28) equipped with an air lift (26) and a recovery device (27), and the recovery device (27 ) Will be collected.

[0004]

The conventional waste plastic separating and collecting apparatus having the above-mentioned structure has the following problems.

(1) It takes a long time for the waste plastic mixture to move from the input tank (21) to the intermediate tank (23) and then from the intermediate tank (23) to the separation tank (23), resulting in poor treatment efficiency. .

(2) Even with waste plastic having a high specific gravity, air tends to adhere to the surface of a hydrophobic plastic such as polyvinyl chloride, so that this kind of waste plastic is separated into a separation tank.
(22) It often surfaced within.

In view of the above points, the present invention improves the structure of the separation / recovery apparatus to completely separate a mixture of waste plastics into a low specific gravity material and a high specific gravity material according to a specific gravity difference, and to efficiently and efficiently separate them. It is an object of the present invention to provide a device that can be separated and recovered in high yield.

[0008]

The apparatus for separating and recovering waste plastics according to the present invention has been devised to achieve the above-mentioned object, and has an input tank for circulating the input waste plastic mixture and a waste plastic mixture. It consists of a separation tank that divides into a low specific gravity material and a high specific gravity material by the difference in specific gravity.A vertical cylinder equipped with a screw is arranged so as to be submerged in the liquid in the charging tank, and the screw forcibly disperses plastic pieces. It is characterized by generating a water flow that causes the dispersion pieces to move to a separation tank.

In the waste plastic separating and collecting apparatus,
The charging tank and the separation tank store water, or water in which a required amount of salt is dissolved in order to increase the specific gravity.

The screw is preferably located in the vertical cylinder, and is rotationally driven by a motor via a shaft fixing the same. The forced water flow generated by the rotation of the screw may be either a descending flow or an ascending flow, but the former is preferred.

[0011]

The waste plastic separating and collecting apparatus according to the present invention is
It consists of an input tank that circulates the input waste plastic mixture, and a separation tank that separates the waste plastic mixture into low specific gravity and high specific gravity according to the difference in specific gravity, so it consists of an input tank, an intermediate tank, and a separation tank. Compared with the conventional device, the time required for separating and collecting waste plastic can be shortened, the device for separating and collecting waste plastic can be downsized, and the amount of liquid required for the treatment can be reduced.

Further, a vertical cylindrical body equipped with a screw is arranged in the charging tank so as to be submerged in the liquid, and the screw generates a water flow forcibly dispersing the plastic pieces in the cylindrical body and separates the dispersed pieces. Since it is designed to be transferred to a tank, air is blown to the surface of a hydrophobic plastic such as polyvinyl chloride as in a conventional device that generates a circulating flow of water or salt water by blowing air from the bottom of the tank. It adheres easily and therefore hydrophobic plastics are
2) It rarely emerges within. Therefore, the separation recovery rate of the waste plastic can be improved.

[0013]

EXAMPLES Next, an example of the separation and recovery apparatus of the present invention will be specifically described.

The waste plastic separating and recovering apparatus shown in FIG. 1 comprises a charging tank (1) for circulating the charged waste plastic mixture, and a separation tank for dividing the waste plastic mixture into low specific gravity and high specific gravity according to the difference in specific gravity. It consists of (2). The input tank (1) has a vertical barrel with a screw (3).
(4) is arranged so as to be submerged in the liquid. screw
(3) is located in the vertical cylinder (4), and is rotationally driven by a motor (7) via a shaft (6) fixing the same. Rotation of the screw (3) causes a downward flow in the vertical cylinder (4), and this downward flow draws the plastic pieces into the vertical cylinder (4), forcibly disperses them, and the dispersion pieces are It can be transferred to the separation tank in a short time.

In the separation tank (2) having almost no flow, the waste plastics are separated into a low specific gravity material (8) such as polyethylene and a high specific gravity material (9) such as polyvinyl chloride. The low specific gravity (8) floats on the surface of the separation tank (2), and the high specific gravity (9) deposits on the bottom of the separation tank (2). The deposit of high specific gravity material (9) is sent to the circulation path (3) equipped with the air lift (10) and the recovery device (11), and is recovered by the recovery device (11).

The rotation of the stirring blade (5) of the screw has almost no influence on the floating, sedimentation and separation of the plastic pieces in the separation tank (2).

In the figure, an air lift is used to collect the high specific gravity material, but instead of the air lift, a pump or a screw may be used to create a circulating flow to recover the high specific gravity material. It is possible.

Polyvinyl chloride pellets (specific gravity 1.19)
Separation and recovery experiments were performed using 100 g of the conventional apparatus and the apparatus of the present invention. The results of this experiment are shown in Table 1.

[0019]

[Table 1] From Table 1, in the waste plastic separating and collecting apparatus according to the present invention, significant improvement is recognized in both the moving time and the collecting rate.

[0020]

The waste plastic separating and collecting apparatus according to the present invention has the following advantages since it is constructed as described above.

1) It is possible to improve the separation and recovery rate of waste plastics.

2) The time required for separating and collecting waste plastic can be shortened.

3) The waste plastic separating and collecting apparatus can be downsized.

4) The amount of liquid required for processing can be reduced.

Thus, according to the apparatus of the present invention, the mixture of waste plastics can be completely divided into a low specific gravity material and a high specific gravity material by the difference in specific gravity, and these can be efficiently separated and recovered in a high yield. .

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an apparatus for separating and collecting waste plastic according to the present invention.

FIG. 2 is a vertical cross-sectional view showing a conventional waste plastic separating and collecting apparatus.

[Explanation of symbols]

 (1) ... Input tank (2) ... Separation tank (3) ... Screw (4) ... Vertical cylinder (5) ... Circulation path (8) ... Low specific gravity (9) ... High specific gravity

Front Page Continuation (72) Inventor Chitoyo Takakura 5-3-8 Nishi-Kujo, Konohana-ku, Osaka City Hitachi Shipbuilding Co., Ltd.

Claims (1)

[Claims] 1. A vertical tank equipped with a screw, which comprises a charging tank for circulating the injected waste plastic mixture and a separation tank for separating the waste plastic mixture into a low specific gravity material and a high specific gravity material according to a difference in specific gravity, and a vertical cylinder provided with a screw. An apparatus for separating and recovering waste plastic, wherein the screw is disposed so as to be submerged in the liquid, and a screw generates a water flow for forcibly dispersing the plastic pieces and transfers the dispersed pieces to a separation tank.