JPH0586724B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention compresses urban or industrial plastic waste into a block shape, heats it, and then cools it to reduce the volume of the plastic waste.
Concerning solidification technology. In particular, plastic containers that roughly separate metals, kitchen waste, etc. from municipal waste, etc.
This invention relates to technology for reducing the volume of waste with low apparent specific gravity, mainly composed of films, etc., solidifying it, and processing it so that it is suitable for landfill.

[Prior Art] A technique for reducing the volume and solidifying plastic waste by compressing it into a block shape and heating it is disclosed in Japanese Patent Application No. 192507/1983. As shown in FIG. 4, a compression lid 202 is attached to the top of the compression chamber 201 with a hinge structure, and can be opened and closed using a lid cylinder 207. The compression chamber 202 is opened and plastic waste is thrown in. do. A main pushing cylinder 208 is attached to the right side of the compression chamber 201 and serves to compress and transport plastic waste. Further, on the left side, a heating duct 204 surrounded by an induction heating coil 203 has almost the same cross-sectional shape as the compression chamber 201 and is directly connected to the heating duct 204. By applying an AC voltage to the heating coil 203, the heating duct 204 is heated. It is heated to the desired temperature by electromagnetic induction.

Further to the left of the heating coil 203 is an unloading chamber 205.
A carry-out cylinder 210 is directly connected to the heating duct 204, and a carry-out cylinder 210 is directly connected in a perpendicular direction to a presser cylinder 209 mounted on the left side, and a carry-out port 206 is provided as an extension of this carry-out cylinder and directly connected to the carry-out chamber 205.

The operation of the conventional device will be described.
Unprocessed plastic waste is put into a compression chamber and then compressed and shaped. After the compression lid is closed by the lid cylinder, when the main push cylinder advances one step, the plastic waste is sealed in a heating duct that has been induction heated in advance, and is heated while being compressed and molded. The outer periphery of the plastic melts and becomes liquid, creating a coating on the surface of the plastic waste. In this compression/forming process, pressure is also applied from the presser cylinder 209 in the opposite direction to the main press cylinder 208 to compress and mold the plastic waste on both sides of each head.

After compression and heating, the molded plastic is transferred to the unloading chamber by the second-stage advancement of the main press cylinder 208 and the retraction of the press cylinder 209, where it is naturally cooled or appropriately forcedly cooled and solidified. Here, by moving the carry-out cylinder 210 forward, the paper is carried out from the carry-out port. When this series of operations is completed, each cylinder returns to its initial state and repeats this process thereafter.

[Problem that the invention seeks to solve]

In the conventional technology mentioned above, heating and transfer are not performed while the object to be processed is being compressed, and all processes are performed in series to process one compression block, so the processing time for one cycle is long. There are problems, and there is also the problem of requiring two cylinders facing each other in the direction of compression.

The purpose of this invention is to solve the above-mentioned problems, and to shorten the processing time of one cycle by performing the compression process and the melting/solidification process in parallel, like a conveyor operation. The aim is to obtain a high volume reduction ratio by minimizing the restoration of the block volume.

[Means for solving problems]

This invention provides a pretreatment chamber with substantially the same inner shape;
A step of sequentially arranging a heating chamber and a cooling chamber to form a processing duct, and sequentially sealing blocks of plastic waste from an opening on the side of the pretreatment chamber, and a duct cylinder in which the blocks are provided in front of the pretreatment chamber. a step in which the duct cylinder is held for a predetermined period of time while applying a pressing force in the heating chamber to melt at least the outer surface portion of the block; After returning the duct cylinder to the initial position, the process of sealing the next block from the opening is repeated, and on the other hand, the blocks successively pressed into the cooling chamber are cooled, solidified, and taken out.

[Effect] The operation will be explained with reference to FIGS. 1 to 3.

When the duct cylinder 14 pushes rearward, a frictional force acts between the series of blocks 20 up to the rear exit of the processing duct 11 and the inner wall of the processing duct 11. This frictional force is integrated toward the front, and a pressing force is generated as a reaction to the integrated frictional force. Therefore, a block in the pretreatment chamber 10 or a block located relatively forward following this block has a stronger compressive force. receive. In this way, the compressed state of the blocks sealed in the pre-processing chamber 10 is not only maintained within the processing duct 11, but even if the blocks to be sealed are insufficiently compressed, they are still compressed within the processing duct 11 by the duct cylinder 14. Ru.

The simply compressed block 20 has a restoring force due to the elasticity of its contents, such as plastic film, and will expand if the compressive force is released. However, when the outer surface becomes a semi-molten state after being kept in the heating chamber 12 for a predetermined period of time, the restoring force of this thick film-like semi-molten part disappears and it has its own strength, so there is an unmelted part inside. Even if the block remains, the restoring power of the block as a whole will be significantly weakened. Thereafter, even when the compressive force on the block, that is, the pressing force of the duct cylinder 14 is released, the block no longer substantially expands. In other words, the block has the property of maintaining its shape by itself in a state of a high volume reduction ratio. This effect becomes even stronger if the block is cooled in the cooling chamber 13. Even if the extremely superficial layer on the outer surface is heated strongly and becomes highly fluid, the restoring force between this fluidized layer and the unmolten part of the center is reduced and the shape is maintained. Since there is always an intermediate layer with properties, the overall shape of the block is maintained. As for the boundary surface 22 between the blocks, since the shape is maintained at the outer periphery of the boundary surface, the unmelted central portion only protrudes a little, and surface strength is generated at the boundary surface, causing the shape to be maintained. It has the property of being maintained, and each block can be taken out independently.

Inside the processing duct 11, a series of blocks advances in response to the pressure and return of the duct cylinder 14, and is sequentially compressed, heated/melted, and cooled/solidified.
It is extruded block by block from the rear end of the processing duct.

〔Example〕

An embodiment of the invention will be explained based on FIGS. 1 to 3. In these drawings, the plastic waste to be treated passes through a hopper 1 and reaches a compression container 2, where a first stage of preliminary compression is performed in an intermediate push cylinder 3, and then the main push cylinder 4 moves forward to fill a compression chamber. 5, a second stage of compression is performed in a direction perpendicular to the first stage.

Next, steps directly related to the invention are carried out. First, the gate 6 having a window is advanced by the gate cylinder 7 to open the front side of the compression chamber 5, and the main push cylinder 4 is further advanced. The compressed block is then sealed in a pretreatment chamber 10 located perpendicular to the treatment duct 11. This is the state shown in FIG. When the duct cylinder 14 provided at the front of the pre-processing chamber 10 moves forward, the plurality of blocks 20 that are successively present in the processing duct 11 move as a whole from the front to the rear inside the processing duct.
The duct cylinder 14 progresses through the entire process having approximately the same size as the width of the gate 6, then stops, and remains in that state for a predetermined period of time. This is the state shown in Figure 2. In this state, the four outer surfaces of the block 20 in the heating chamber 12 are heated and melted via the inner wall of the duct by the heating coil 12a which has an induction heating effect. For example, in the case of a block with a side of 700 mm and a heating power of 270 kW, after holding for a predetermined time of 3 to 7 minutes, the duct cylinder 14, that is, its head 14
a returns to the initial position as shown in FIG. 3, but the block 20 in contact with this head 14a
The restoring force of the block no longer weakens and it no longer expands in the direction of the pretreatment chamber 10, and at the same time, a surface strength is generated at the boundary surface 22 between the blocks to maintain a strength that will not collapse. As shown in FIG. 3, by the time the duct cylinder 14 returns to the initial position, the next block is waiting in the compression chamber 5 in front of the closed gate 6 as described above, and then the process continues as before. Repeat the process.

On the other hand, the molten outer surface of the block 20 advancing from the heating chamber 12 to the cooling chamber 13 is cooled and solidified by the water-cooling jacket 13a through the inner wall of the duct, thereby further enhancing its ability to maintain its shape as a block. Ru. Thus, the processing duct 11
The blocks pushed out from the rear end fall one by one onto the conveyor 15 and are carried out, as shown in FIG.

Different aspects of the above embodiment will now be described.

In FIG. 1, the gate 6 is removed, and the compression by the main push cylinder 4 is carried out in the compression chamber 5 and pretreatment chamber 10.
The duct cylinder 14 may be operated in the same manner as described above. . Further, by providing a hopper directly on the upper surface of the pretreatment chamber 10, the blocks to be sealed (in this case, the blocks have a small density) can be substantially completely compressed in the pretreatment chamber 10. At this time, the pretreatment chamber is made sufficiently long in the duct direction,
Also, variations in length of the finished solidified block must be allowed for.

The processing duct can be easily tapered in the longitudinal direction to control the aforementioned frictional force on the inner wall of the duct, that is, the compression ratio of the block. A portion of the inner wall of the duct may be controlled by being movable in a direction perpendicular to the longitudinal direction of the duct.

For heating, atmospheric heating from the outside or electric resistance heating of the inner wall itself can be used, and the cooling chamber may simply be provided with a long processing duct 11 for natural cooling.

〔Effect of the invention〕

This invention has the following effects.

(1) Blocks of plastic waste are intermittently sealed into the processing duct via the pre-treatment chamber, and the processes of compression, heating/melting, cooling/solidification in the processing duct can be performed continuously. Each process is continuous, reducing the total processing time.

(2) Since the frictional force of the inner wall of the processing duct is used, blocks can be passed into the processing duct using only the duct cylinder from the front, eliminating the need for holding cylinders and delivery cylinders as in the past, and reducing the need for a processing drive device. can be made extremely simple and save power.

(3) The shape maintenance effect produced by heating the outer surface can suppress the restoring force of the compressed block even when the duct cylinder retreats, so the volume reduction ratio of the block is high.

(4) Overall, there is no collapse or peeling of the block surface, so fine particles such as cullet and powder inside the compression block do not leak out, and the large surface binding force reduces bulges after being taken out to the outside. The volume ratio also increases further, resulting in significant improvements in transport handling, loading efficiency, and the ultimate goal of waste landfill efficiency.

[Brief explanation of the drawing]

1 to 3 are partially sectional perspective views showing each step of the apparatus according to the method of the present invention, and FIG. 4 is a perspective view of the apparatus according to the conventional method. 1... Hopper, 5... Compression chamber, 10... Pre-treatment chamber, 11... Processing duct, 12... Heating chamber, 13
...Cooling chamber, 14...Duct cylinder, 20...
Block, 22... Boundary surface.

Claims (1)

[Claims] 1. Constructing a processing duct by sequentially arranging a pretreatment chamber, a heating chamber, and a cooling chamber with substantially the same inner shape, and sequentially sealing blocks of plastic waste from the opening on the side of the pretreatment chamber; and A step of pressing with a duct cylinder provided in front of the pretreatment chamber to transfer the block to the heating chamber and temporarily stopping it; and a step of holding the duct cylinder for a predetermined time while applying a pressing force in the heating chamber to reduce the amount of the block. The steps of melting the outer surface of each block and then returning the duct cylinder to its initial position and sealing the next block from the opening are repeated, while the blocks successively pushed into the cooling chamber are cooled. , a method for reducing the volume and solidifying plastic waste, characterized by solidifying and removing it.