Screw conveyor-type washing and dewatering apparatus for waste plastics

Abstract

To provide a screw conveyor-type washing and dewatering apparatus for waste plastics that not only conveys waste plastics on a screw conveyor rotating over a screen but also loosens aggregated crushed pieces, thereby enabling efficient dewatering of the dispersed crushed pieces.SOLUTION: A washing and dewatering apparatus for dewatering crushed pieces of plastic waste that has been pulverized and liquid-cleaned comprises: a dewatering tank 2 having a semi-cylindrical screen 5 with numerous holes formed in a housing; a screw blade 4 spirally wound around a rotating shaft 3 that rotates inside the dewatering tank 2; and at least one striking plate 9 attached along the length of one pitch (P) of the screw blade 4.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a waste plastics recycling system for cleaning and dehydrating finely cut pieces of waste plastics when recycling discarded plastics. Screw conveyor type This relates to a cleaning and dehydrating device. [Background technology]

[0002] Discarded plastic bottles, disposable plastic containers, plastic products, food cups, and other waste plastics contain dirt. or Paper labels, food and condiment residues etc. Vegetables or Waste plastics from agriculture, such as greenhouse covering materials used in fruit production, agricultural mulch, fertilizer bags, silage wrap films, and seedling trays, contain soil, sand, and pesticides. etc. There is dirt on it. In addition, the clear file or Waste plastics such as packaging materials for flexible disks, CDs, and DVDs (wrapping film, PP bands) often have dirt, paper, stickers, etc., attached to them. There is also waste plastic such as used lunch boxes that are still in their bags.

[0003] In this way, for waste plastics that have dirt, food, various seasonings, or paper label residues attached, or agricultural or industrial waste plastics such as plastic sheets that have soil or fertilizer residues attached, the waste plastics are carefully separated from the residues and washed before being recycled in order to increase the accuracy of the recycling process.

[0004] Therefore, a technique for washing waste plastics when recycling them has been proposed. For example, Patent Document 1, JP 2008-80679 A, ​​"Waste Plastic Washing Device," proposes a waste plastic washing device in which an agitating blade is provided inside a cylindrical screen so as to be rotatable around the cylindrical axis of the screen, and the agitating blade is rotated to separate foreign matter adhering to the waste plastics put into the screen and discharge the waste plastics outside the screen, in which the gap between the inner peripheral surface of the screen and the tip of the agitating blade changes in size in the direction of rotation of the agitating blade.

[0005] Naturally, there is a lot of moisture on the crushed pieces of waste plastic that have been washed with water. Screw conveyor type dehydrators have been used for the dehydration of these crushed pieces of waste plastic. These dehydrators have a screw conveyor placed on a screen such as a semi-cylindrical mesh plate inside the main body of the device, and the screw conveyor is rotated to move the crushed pieces of waste plastic while allowing the moisture to fall and be separated from the screen. The screw conveyor is rotated at a high speed to utilize centrifugal force. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP2008-80679A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in a screw conveyor type dehydrator, while the efficiency of water separation can be increased by rotating the screw conveyor quickly due to the effect of centrifugal force, the residence time on the screen is shortened, which may result in insufficient dehydration.

[0008] Furthermore, when the lumps of crushed waste plastics are large and difficult to break apart, there is a problem in that the efficiency of water separation does not increase if the lumps are simply moved on the screen.

[0009] The inventors of the present invention focused on the fact that the efficiency of water separation can be improved by breaking up the lumps of crushed plastic waste before dehydrating them. They also focused on the fact that water can be scattered by beating the lumps of crushed plastic waste while they are being transported.

[0010] The present invention has been invented to solve such problems. That is, the object of the present invention is to provide a screw conveyor that rotates on a screen that not only conveys waste plastics but also breaks up lumps of crushed pieces, thereby enabling the efficient dehydration of the dispersed crushed pieces of waste plastics. Screw conveyor type To provide a washing and dewatering device. [Means for solving the problem]

[0011] The present invention is a screw conveyor type waste plastics washing and dehydration device for dehydrating crushed pieces of plastic waste that have been crushed and washed with a liquid, A dewatering tank (2) having a semi-cylindrical screen (5) with a large number of holes formed in the housing; a screw blade (4) wound in a spiral shape around a rotating shaft (3) that rotates in the dewatering tank (2); One pitch (P) of the screw blade (4) Between them, two points of the screw blade (4) are arranged so as to span the longitudinal direction of the rotating shaft (3). Attached to Square plate-like Beating board(9) One or more The present invention is characterized by comprising: A washing tank (1) is disposed adjacent to the dehydration tank (2), The rotating shaft (3) having the screw blades (4) is provided so as to penetrate both the dewatering tank (2) and the washing tank (1).

[0012] The screw blade (4) has a plurality of The striking plate (9) It is preferable to have a . The striking plate (9) is arranged so as not to come into contact with the rotating shaft (3). It is possible to attach the screw blade (4) at two points during one pitch (P) of the screw blade (4). .

[0013] Each of the multiple beating plates (9) is spaced from the inner surface of the semi-cylindrical screen (5) by both Arranged so that they are spaced equally (C) Can be do. Each of the multiple beating plates (9) is spaced from the inner surface of the semi-cylindrical screen (5) by each Different things can be arranged. Effect of the Invention

[0014] In the present invention, crushed waste plastics are fed into the feed inlet (6) and then poured into the cleaning tank (1). oh The crushed waste plastic pieces can be washed with water by the screw blade (4). The washed crushed waste plastic pieces are transported by the same screw blade (4) to the dewatering tank (2) adjacent to the washing tank (1). The water adhering to the crushed waste plastic pieces falls from the semi-cylindrical screen (5) as they are transported by the screw blade (4) and is separated. The pieces are transported as they are to the discharge outlet by the screw blade (4). In particular, the beating plate (9) attached to the screw blade (4) has the function of breaking up lumps of the crushed waste plastic pieces being transported. When breaking up the lumps, the water scatters and can fall directly from the semi-cylindrical screen (5).

[0015] Depending on the characteristics and size of the crushed waste plastic pieces, Multiple sheets Semi-cylindrical screen (5) for each beating board (9) of Use the one with the optimum distance from the inner surface. If there is no variation in the size of each side of the crushed waste plastic pieces, it is suitable for each beating plate (9) to be arranged so that the distance from the inner surface of the semi-cylindrical screen (5) is uniform.

[0016] In the case of crushed waste plastic pieces with uneven sizes and a wide range of sizes, Multiple sheets Each beating plate (9) is a semi-cylindrical screen (5) ofA semi-cylindrical screen (5) is suitable for handling small pieces of crushed material. of The crushed pieces are captured by a beating plate (9) with a short gap between the inner surface and the crushed pieces, and the moisture is separated. On the other hand, when processing large crushed pieces, a semi-cylindrical screen (5) is used. of The beating plate (9), which has a long gap between it and the inner surface, can capture the crushed pieces and separate the moisture. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a front sectional view of a screw conveyor-type washing and dewatering device for waste plastics according to a first embodiment. [Diagram 2] FIG. 1 is a cross-sectional plan view showing a screw conveyor-type washing and dewatering device for waste plastics in Example 1. [Diagram 3] FIG. 4 is an enlarged front view showing a screw blade with a striking plate attached thereto. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing a screw blade with a striking plate attached thereto. [Diagram 5] FIG. 13 is an enlarged front view of a screw blade showing a striking plate of modified example 1. [Figure 6] FIG. 11 is an enlarged front view of a screw blade showing a striking plate of modified example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The screw conveyor type washing and dehydrating apparatus of the present invention is a washing and dehydrating apparatus for waste plastics which crushes plastic waste, washes the crushed pieces with water, and removes moisture therefrom. EXAMPLES

[0019] [ Screw conveyor type Washing and dehydration equipment configuration Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the waste plastics of Example 1. Screw conveyor type FIG 2 is a front sectional view of a washing and dewatering device for waste plastics in Example 1. Screw conveyor type2 is a cross-sectional plan view of the washing and dewatering device. Note that in Fig. 2, the rotation shaft is rotated 90 degrees so that the beating plate can be seen. Waste plastics in Example 1 Screw conveyor type The washing and dehydrating apparatus has a washing tank 1 and an adjacent dehydrating tank 2. The apparatus is equipped with a rotating shaft 3 that penetrates both the washing tank 1 and the dehydrating tank 2, and a screw blade 4 wound in a spiral shape around the rotating shaft 3. A semi-cylindrical screen 5 for dehydration, which will be described later, is provided within the dehydrating tank 2. The apparatus also has a driving device 8, such as a motor, that drives the rotating shaft 3 to rotate. In the illustrated example, the washing tank 1 and the spin-drying tank 2 are shown as separate structures, but they can be housed within the same apparatus body to provide a compact structure (not illustrated).

[0020] The cleaning tank 1 is, for example, a box having a roughly rectangular parallelepiped shape, and has an inlet 6 at the top for inserting crushed pieces of crushed waste plastics. It also has side and bottom plates for preventing the scattering of the crushed waste plastics. The side and bottom plates have drainage outlets 7 for discharging the cleaning water and dehydrated water to the outside.

[0021] In the cleaning tank 1, Screw blade 4 By rotating the spirally wound rotating shaft 3, the crushed pieces of waste plastics are crushed using water, etc. hand The liquid is washed. The rotating shaft 3 (screw blade 4) is rotated by a driving device 8 such as a motor provided adjacent to the washing tank 1. The driving device 8 is adapted to rotate in both forward and reverse directions.

[0022] The dehydration tank 2 is disposed adjacent to the washing tank 1. The dehydration tank 2 is a roughly rectangular parallelepiped housing with side panels, a top panel, and a bottom panel that prevent the crushed pieces of waste plastics from scattering during dehydration. Furthermore, the tank has a semi-cylindrical screen 5 below the screw blades 4 that are arranged to penetrate the inside. The semi-cylindrical screen 5 is a screen with many holes that remove moisture from the crushed pieces of crushed waste plastics.

[0023] The distance between the inner surface of the semi-cylindrical screen 5 and the outer edge of the spiral screw blade 4 is about 10 mm to 20 mm. This distance is variable depending on the size of the crushed pieces of waste plastics, or the properties of the crushed pieces of waste plastics. The distance is variable depending on the target material, such as soft plastics, hard plastics, or thick plastics.

[0024] [Strike board configuration] Fig. 3 is an enlarged front view showing a screw blade with a striking plate attached, and Fig. 4 is an enlarged sectional view showing a screw blade with a striking plate attached. The configuration of the screw blade 4 in the dewatering tub 2 is basically the same as that of the screw blade 4 in the washing tub 1. The screw blade 4 arranged in the dewatering tub 2 has square striking plates 9 attached at several points.

[0025] 1 pitch of screw blade 4 (P) between To 、 Beating Board 9 of As if to bridge the gap In two places In the illustrated example, For one screw blade 4, 3 Pieces An example in which a square striking plate 9 is attached is shown.

[0026] The beating plate 9 is arranged so that its plate plane is aligned along the longitudinal direction of the screw blade 4 (rotating shaft 3) and along the radial direction of the rotating shaft 3. The beating plate 9 attached to the screw blade 4 has the function of breaking up lumps of crushed waste plastic pieces being transported. When breaking up these lumps, moisture scatters and falls directly from the semi-cylindrical screen 5. vinegar do.

[0027] In the illustrated example, three striking plates 9 are attached to one screw blade 4 (rotating shaft 3). The three striking plates 9 are just an example, and four or more striking plates 9 may be attached depending on the length of one screw blade 4. 2 pieces or lessIn the illustrated example, the three striking plates 9 are arranged in a straight line along the axial direction of the screw blade 4 with one pitch (P) between them, but this is only an example and they do not necessarily have to be arranged in a straight line. Also, they do not necessarily have to be arranged with one pitch (P) between them.

[0028] In addition, the rectangular striking plate 9 of the present invention is shown in a state where one side of the striking plate is not in contact with the rotating shaft 3. of The original function is a screw conveyor that's why It is not preferable that the beating plate 9 interferes with the transport of the crushed waste plastic pieces or their lumps. However, when the crushed waste plastic pieces are large, they can be moved beyond the beating plate 9. Therefore, one side of the rectangular beating plate 9 is located on the rotation axis 3. Axial surface of It may be attached so as to be in contact with the

[0029] The illustrated example shows the beating plate 9 as a flat plate, but it may be a curved plate. Furthermore, although a square shape parallel to the axial direction of the rotating shaft 3 is shown, this is not necessarily limited to a rectangular shape. As long as it has the function of breaking up lumps of crushed waste plastic pieces, it can be in various shapes such as a trapezoid, bow shape, or pentagonal shape.

[0030] The striking plate 9 is arranged so that one side does not come into contact with the rotating shaft 3. The multiple striking plates 9 are arranged so that the distance between each of the plates and the inner surface of the semi-cylindrical screen 5 is the same.

[0031] Properties of crushed waste plastic fragments or Depending on the size, use the one with the optimum distance between each beating plate 9 and the inner surface of the semi-cylindrical screen 5. When the size of each side of the crushed waste plastic pieces is nearly uniform, it is suitable to arrange the multiple beating plates 9 so that the distance between each plate and the inner surface of the semi-cylindrical screen 5 is the same distance (C).

[0032] [Variation 1 of the beating board] FIG. 5 is an enlarged front view of a screw blade showing a striking plate of the first modified example. The intervals between each of the multiple beating plates 9 and the inner surface of the semi-cylindrical screen 5 do not necessarily have to be the same. As shown in the figure, the multiple beating plates 9 may be arranged with different intervals between each of the multiple beating plates 9 and the inner surface of the semi-cylindrical screen 5. In the case where the size of each side of the crushed waste plastic pieces is not uniform and there is a large difference in size between the pieces, it is suitable to arrange the multiple beating plates 9 with different intervals (C1, C2, C3) between them and the inner surface of the semi-cylindrical screen 5. In Figure 5, the interval (C1) is the longest on the input side (inlet 6) and gradually becomes shorter (C2, C3) towards the discharge side.

[0033] When processing large crushed pieces, the crushed pieces are caught and the moisture is separated even if the gap between the semi-cylindrical screen 5 and the inner surface is long (C1). Conversely, when processing small crushed pieces, the crushed pieces are caught and the moisture is separated by the semi-cylindrical screen 5 with a short gap between the semi-cylindrical screen 5 and the inner surface (C3).

[0034] [Variation 2 of the beating board] FIG. 6 is an enlarged front view of a screw blade showing a striking plate of the second modified example. Modification 2 is the same as Modification 1. is reversed The distance (C4) between the inlet side (inlet 6) and the inner surface of the semi-cylindrical screen 5 is short, and the distance gradually increases (C5, C6) toward the outlet side.

[0035] Furthermore, the present invention is not limited to the above-described embodiment of the invention, and can of course be modified in various ways without departing from the gist of the present invention, so long as the screw conveyor rotating on the screen is given the function of breaking up clumps of crushed plastic in addition to transporting the waste plastic, thereby enabling the dispersed crushed pieces to be efficiently dehydrated. [Industrial Applicability]

[0036] The waste plastics of the present invention Screw conveyor typeThe cleaning and dehydrating device can be used mainly for recycling plastic containers, plastic products, or vinyl sheets for greenhouse cultivation agriculture. [Explanation of symbols]

[0037] 1 Cleaning tank 2 Dehydration tank 3 Rotation Axis 4 Screw blade 5. Semi-cylindrical screen 9. Beating Board P: One pitch of the screw blade C Distance between the striking plate and the inner surface of the semi-cylindrical screen

Claims

1. A screw conveyor-type waste plastics washing and dehydration device for dehydrating crushed pieces of plastic waste that have been crushed and washed with a liquid, A dewatering tank (2) having a semi-cylindrical screen (5) with a large number of holes formed in the housing; a screw blade (4) wound in a spiral shape around a rotating shaft (3) that rotates in the dewatering tank (2); and a beating plate (9) attached at one or more points along the length of one pitch (P) of the screw blade (4).

2. A washing tank (1) is disposed adjacent to the dehydration tank (2), 2. The washing and dewatering device for waste plastics as described in claim 1, characterized in that a rotating shaft (3) having the screw blades (4) is provided so as to penetrate both the dewatering tank (2) and the washing tank (1).

3. 3. The waste plastics washing and dewatering device according to claim 1 or 2, characterized in that the beating plate (9) is a rectangular plate material whose plate plane is arranged along the longitudinal direction of the rotating shaft (3) and along the radial direction of the rotating shaft (3).

4. 2. The apparatus for washing and dewatering waste plastics according to claim 1, wherein the beating plate (9) is arranged so that one side of the beating plate does not come into contact with the rotating shaft (3).

5. 3. A washing and dewatering device for waste plastics as described in claim 1 or 2, characterized in that each of the multiple beating plates (9) is arranged so that the distances between each plate and the inner surface of the semi-cylindrical screen (5) are equal (C).

6. 3. The washing and dewatering device for waste plastics according to claim 1 or 2, characterized in that each of the plurality of beating plates (9) is arranged at different intervals from the inner surface of the semi-cylindrical screen (5).

Images