JP2001210160A - Device for recovering vinyl chloride resin from vinyl chlorine waste contained in plastic covered with scraps - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device to remove contaminants from plastic insulation refuse of the disassembled insulated wires recovered after used, by removing hazardous foreign matters, dissolving the refuse in a solvent and evaporating the solvent for recycling. SOLUTION: The device recovering vinyl chloride resin crushes the used wires, recovers vinyl chloride waste fro the crushed pieces as required, disolves the vinyl chloride waste in a solvent removes solid contents from the solution by using a separation device, and evaporates the solvent after separating the solid contents with an evaporator the evaporator has airtight evaporation chamber, and is featured in that it is divided into plural compartments from the bottom to a certain height. Thus, the solvent disolving vinyl chloride can be efficiently evaporated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to collect and disassemble used plastic-coated electric wires, disassemble them, firstly separate the waste plastics from the disassembled plastic electric wires into copper and plastic waste, and then convert the plastic waste to polyvinyl chloride waste. The present invention relates to an apparatus for recovering vinyl chloride resin from waste vinyl chloride contained in wire-covered waste, which can be reused or discarded from the separated vinyl chloride waste, which is separated into waste and other waste materials. .

[0002]

2. Description of the Related Art Wires, particularly wires wired outdoors, are replaced after a certain period of use in consideration of their safety. The replaced waste wire is separated into a conductor (mainly copper) and a covering waste material (mainly plastic). Among the separated coated waste materials, a method of reusing (recycling) the coated waste materials made of petroleum-based materials as fuel instead of petroleum-based energy has been developed. On the other hand, the reuse (recycling) of coated waste materials mainly composed of vinyl chloride is delayed, and most of them are landfilled.

In the recycling of waste electric wires, first, electric wires are separated into conductors (copper) and coated waste materials (plastic). Separation of the conductor and the coating waste material can be divided into the following two methods depending on the size of the electric wire. (1) Electric wire with a conductor diameter of 1.6 mm or more The collected waste electric wire is cut to a certain length, disassembled to a cable core, and the cable core is peeled off from the conductor by a stripping machine to cover the conductor. A method of separating waste materials (hereinafter referred to as stripping method). (2) Electric wire with a conductor diameter of less than 1.6 mm The collected waste electric wire is put into an automatic crusher, and the conductor and the coated waste material are finely cut together and crushed (nugget treatment). And a coating waste material (hereinafter referred to as a nugget method).

[0004]

Since the above-mentioned electric wire having a large conductor size is separated and collected into a conductor and a coating material by a stripping method, copper is hardly adhered to the recovered coating waste material. Therefore, the coating waste material can be directly transferred to the reprocessing step. On the other hand, wires made of thin wires such as communication wires are cut and pulverized (nugget treatment) without being separated into polyethylene-coated wires or polyvinyl chloride-coated wires in the recovery process, so copper, polyethylene, vinyl chloride, etc. are mixed. ing.

Recently, research on material recycling has been promoted in response to the demands of a resource-recycling society, and the application of this material recycling to the recycling of wire covering waste materials has been studied. Copper, polyethylene, vinyl chloride, and the like are mixed in the nugget waste material of the plastic-coated waste wire as described above. Since material recycling cannot be applied to nugget waste containing copper, polyethylene, vinyl chloride, etc., it is necessary to separate and separate nugget waste into individual components such as copper, polyethylene, vinyl chloride, etc. Is being requested. For this reason, first, polyethylene waste materials floating in water are separated from the crushed pieces, and the remaining copper and vinyl chloride waste materials are separated into copper and coated waste materials (mainly vinyl chloride) by a specific gravity difference method. The separated vinyl chloride waste is reprocessed (dechlorination, decopperization) and reused as alternative energy (raw material for blast furnaces), or landfill disposal. However, DOP is used as a plasticizer for vinyl chloride in vinyl chloride waste materials,
Also, since lead is contained as a heat stabilizer, there is a concern that soil will be contaminated if discarded as it is.

Accordingly, the present inventors have conducted intensive studies on the reuse of vinyl chloride-coated waste materials, and have found that other components contained in the vinyl chloride waste material, copper, and additives (mainly lead compounds) contained in the vinyl chloride. Calcium carbonate) has been removed, and a processing method that can be recycled as a raw material for blast furnaces or that does not cause pollution problems even when disposed of has been completed.
An apparatus that efficiently performs the processing has been successfully improved.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a plastic-coated waste wire is crushed, if necessary, vinyl chloride waste material is selected from the crushed pieces, the vinyl chloride waste material is dissolved in a solvent, and solid content is removed from the solution. In a device for separating a solid content separated by a solid-liquid separator and evaporating the solvent with a solvent evaporator to recover a vinyl chloride resin, the solvent evaporator has an evaporation tank that can be airtight, At least the bottom of the tank is partitioned into a plurality of rooms, and is a device for recovering vinyl chloride from waste vinyl chloride contained in waste plastic-coated electric wires.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. In the present invention, copper is first separated from waste nugget by a difference in specific gravity. Next, in the water, vinyl chloride waste material and polyethylene waste material are separated, and the polyvinyl chloride waste material submerged in the water and the copper that has not been completely removed are separated and removed by a vibration-type wet specific gravity discrimination device. The additives contained in the vinyl chloride are removed, and recovered as a vinyl chloride resin free of copper and other plastic waste materials. In addition, as for the electric wire waste material having a conductor diameter of 1.6 mm or more, since the waste material is classified as the vinyl chloride waste material, the waste material is pulverized to an appropriate size, and the additive compounded in the vinyl chloride is added to the present invention. It is removed by a device and recovered as a vinyl chloride resin.

FIG. 1 shows an embodiment of the present invention.
This shows the step of removing the additives mixed with vinyl chloride from the vinyl chloride waste material. Reference numeral 1 denotes a dissolving and filtering tank. The dissolving and filtering tank 1 includes a dissolving tank 2 at an upper part and a storage tank 3 at a lower part. 2 is provided with a raw material supply port 4 for charging waste vinyl chloride, a solvent supply pipe 5 for supplying a solution for dissolving vinyl chloride, and a stirrer 6, and a filtering means 7 (at the boundary between the dissolution tank 2 and the storage tank 5). For example, a wire mesh having a predetermined mesh is provided, and the entire dissolution filtration tank 1 is configured to be heated by a heating device (not shown).

The waste vinyl chloride material supplied from the raw material supply port 4 of the dissolving tank 2 and the solvent (eg, tetrahydrofuran) injected from the solvent supply pipe 5 are mixed by the stirrer 6 so that the waste vinyl chloride material is dissolved, and the vinyl chloride waste material is dissolved. The solution in which the waste material is dissolved is filtered by the filtering means 7 and accumulated in the storage tank 3. In the drawing, a pipe 8 is a conduit for circulating the solution to the dissolving tank 2, and a solution having a low solubility of vinyl chloride is returned to the dissolving tank 2 to further dissolve the vinyl chloride to increase the concentration. . By dissolving the vinyl chloride waste material in the dissolving tank 2, the vinyl chloride dissolves and is filtered by the filtering means 7 and stored in the storage tank 3. Components insoluble in the solvent (copper, polyethylene, etc. mixed in the waste vinyl chloride) cannot pass through the filtration means 7 and are separated and removed.

The solution stored in the storage tank 3 is supplied to a solid-liquid separation device 11 comprising a centrifugal separator, where the lead (calculated as a heat stabilizer for vinyl chloride and added as a filler) and calcium are added. And other solids. The solution from which the solid content has been removed is supplied to a solvent evaporating tank 22 of a solvent evaporating apparatus 21 including a solvent evaporating tank 22 and a heating device 23 which can be airtight, and the solvent is evaporated off to recover the vinyl chloride resin.
In the figure, reference numeral 29 denotes a solvent recovery means, which comprises a heat exchanger 24 and a tank 25. In the drawing, reference numeral 27 denotes a decompression pump (vacuum pump) which decompresses the inside of the solvent evaporation tank 22 by the pump to evaporate the solvent at a low temperature, thereby improving the evaporation efficiency.

FIG. 2 is a cross-sectional view of the solvent evaporating tank 22. As shown, the interior of the solvent evaporating tank 22 is divided into a plurality of small chambers 28 by a partition plate 26 from a bottom to a predetermined height.
For the partition plate 26, a material having excellent heat conductivity is selected. The partition plate 26 may be formed integrally with the solvent evaporation tank 22,
Alternatively, a separately assembled member in a lattice shape may be set in the solvent evaporation tank. The height of the partition plate depends on the amount of the solution to be treated at a time, but the height is arbitrary as long as the solution is configured to uniformly enter all the rooms partitioned by the partition plate.

By providing a partition plate 26 in the solvent evaporation tank 22 and partitioning the inside of the solvent evaporation tank into a plurality of chambers 28, the solvent can be efficiently evaporated from the solution containing the vinyl chloride resin, and the vinyl chloride resin can be recovered. Work is greatly improved. No partition plate in the solvent evaporation tank (conventional method)
When the solvent is evaporated from the solution to recover the vinyl chloride resin, the solvent evaporates from the heating surface (mainly the bottom wall surface) of the solvent evaporation tank 22 for heating the solution. It begins to solidify from the 22 wall. That is, a vinyl chloride resin film starts to be formed from the bottom wall portion (portion transmitting heat). When a vinyl chloride resin film is formed on the heating wall surface, the heat conductivity of the vinyl chloride resin is inferior to that of the metal, so that heat is hardly transmitted to the solution in the solvent evaporating tank 22 and the thermal efficiency is greatly deteriorated.

The evaporation of the solvent from the solution and the solidification of the vinyl chloride resin begin with solidification from the wall of the evaporating tank where heat is well transmitted and the surface of the solution, and then solidify in the form of a film. Solidify to thicken. For this reason, the unevaporated solution is wrapped in a vinyl chloride resin film (solidified portion), so that the solvent is less likely to escape from the center, and it is extremely difficult to completely remove the solvent. Therefore, after removing the solvent to some extent, solid content (vinyl chloride resin)
Is removed from the solvent evaporation tank, cut into small pieces, and the solvent is removed again to completely remove the solvent.

According to the present invention, as described above, the solvent evaporation tank 2
2, a partition plate 26 is provided to remove the solvent by evaporation. By providing the partition plate 26, the heat transmission path to the solution is transmitted from the wall surface of the solvent evaporation tank 22 to the partition plate 26, and the heat is transmitted from the partition plate to the solution. Even if the transmission area spreads remarkably, and the vinyl chloride resin solidifies to form a film and the thermal conductivity deteriorates, the volume of each room 28 is small, so that the evaporation of the solvent in each room is not so affected. Therefore, the efficiency of solvent removal by evaporation is significantly improved. In addition, when the vinyl chloride resin is removed from the solvent evaporation tank after the solvent is evaporated, the temperature of the evaporation process (about 85 ° C.) drops to the temperature at the time of removal (room temperature). In addition, since the vinyl chloride resin can be taken out in units of 28 units, there is an accompanying effect that the cutting work after taking out is unnecessary. The solvent evaporated in the solvent evaporation tank 22 is cooled by the heat exchanger 24 and stored in the tank 25 and collected. The recovered solvent can be used again for dissolving the vinyl chloride waste material.

[0016]

Example 1 A partition plate 26 made of a 3.5 mm-thick stainless steel plate (the size of each room is 5 cm × 5 cm × 8 cm average) was set in the solvent evaporation tank 22 so as to be in contact with the wall surface of the solvent evaporation tank. . The solution obtained by removing the impurities in the previous step from the vinyl chloride waste material solution dissolved in tetrahydrofuran was put into this evaporating tank, and the solvent was removed while reducing the pressure at 85 ° C. The result is shown in FIG. As is apparent from FIG.
After time, about 88% of the solvent was removed.

[0017]

Comparative Example 1 An experiment was conducted in which the solvent was removed from the solution under the same conditions as in Example 1 without providing a partition plate in the solvent evaporation tank used in Example 1. The results are also shown in FIG. As is clear from FIG. 3, the solvent removal rate after 5 hours is about 60%, and even after 8 hours, it is about 70%, indicating that the solvent removal efficiency does not increase.

In the above embodiment, tetrahydrofuran was used as a solvent. However, any solvent may be used as long as a vinyl chloride resin such as dimethyl sulfoxide, ethylene chloride, methylene chloride, and tetralin can be dissolved therein. When it is necessary to dilute the solvent, acetone, ethyl acetate, methyl acetate, ethyl alcohol, methyl alcohol, or the like can be used as a diluent.
Further, as the filtering means 7, it is preferable to use a wire mesh of 60 to 325 mesh, but in particular, using a filtering material having a fine opening to remove fine crushed pieces increases the time required for the filtering step. Therefore, the pulverized pieces that cannot be removed by the filtration means are not preferable,
Therefore, it is preferable to select a filter material having openings in consideration of the working efficiency.

A partition plate 26 for partitioning the inside of the solvent evaporation tank 22
Any material may be used as long as it has excellent thermal conductivity and does not corrode with the solvent used, and its thickness depends on the amount of the solution to be treated, but is preferably about 2 to 5 mm. Also, the shape of the room to be partitioned is not particularly limited, such as square, hexagon, circle, etc.
A shape that is easy to manufacture can be selected.

[0020]

As described above in detail, according to the apparatus of the present invention, copper and other waste materials are not contained in the waste wire coating waste material, and the additive to the vinyl chloride which is harmful to the environment and the like is also eliminated. The removed vinyl chloride resin can be recovered extremely efficiently. Therefore,
By dechlorinating vinyl chloride, which is a wire covering waste material, it can be reused as a raw material for blast furnaces, or material recycling can be applied.Furthermore, it is possible to dispose of landfill without worrying about soil contamination etc. It has excellent effects.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one embodiment of the present invention.

FIG. 2 is a schematic explanatory view showing one embodiment of an evaporation tank used in the present invention.

FIG. 3 is a graph showing the effect of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dissolution filtration tank 2 Dissolution tank 3 Storage tank 7 Filtration means 11 Solid-liquid separation device 21 Solvent evaporator 22 Solvent evaporation tank 23 Heating means 24 Heat exchanger 25 Tank 26 Partition plate 28 Partitioned room 29 Solvent recovery means

Claims (1)

[Claims] 1. A plastic-coated waste wire is crushed, if necessary, vinyl chloride waste material is selected from the crushed pieces, the vinyl chloride waste material is dissolved with a solvent, and a solid content is separated from the solution by a solid-liquid separator. In a device for recovering a vinyl chloride resin by evaporating the solvent with a solvent evaporating device from a solution from which a solid content is separated, the solvent evaporating device has an evaporating tank that can be airtight, and a predetermined height from the bottom of the evaporating tank. Is a device for recovering vinyl chloride resin from waste vinyl chloride contained in plastic-coated electric wire waste, which is divided into a plurality of rooms.