JPH11138539A - Shrink treating method of waste foamed urethane material and method for feeding waste foamed urethane material to furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treating method for turning waste foamed urethane materials in a reusable state as resources and, at the same time, a feeding method for the waste foamed urethane materials to a furnace as raw materials or the substitute materials for fuels. SOLUTION: In a treating method for turning in a reusable state, waste foamed urethane materials are thermally softened and kneaded in the state being compressed so as to be shrunk and next cooled and solidified. Or, in a method for feeding to a furnace such as a blast furnace or the like, the waste foamed urethane materials are thermally softened and kneaded in the state being compressed so as to be shrunk in order to granulate this shrunken kneaded matter for blowing the granulated matter in the furnace through an airborn transportation. At the thermally softening of the waste foamed urethane materials, the preliminary mixing of a thermoplastic resin with the waste foamed urethane materials is preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for recycling urethane foam waste, a method for shrinking urethane foam waste, and a method for supplying urethane foam waste as a raw material or fuel to a furnace such as a blast furnace.

[0002]

2. Description of the Related Art Synthetic resins are easy to mold and have the property of being chemically stable, so that their products are manufactured in large quantities. When these products become waste materials, most of them are disposed of at landfills without being reused. However, it becomes difficult to secure landfill sites year by year, and the synthetic resin remains as it is without being decomposed by microorganisms. Therefore, various problems related to landfill disposal have occurred. For this reason, there is a strong demand for the development of a technique for recycling synthetic resin waste as a resource.

[0003] Under such circumstances, as one method of recycling synthetic resin waste, Japanese Patent Application Laid-Open No. Hei 9-13792 has been proposed.
No. 6 discloses a method in which the waste material is crushed, blown into a furnace such as a blast furnace, and used as a substitute material for a carbon material.

By the way, urethane foam, which is a kind of synthetic resin material, is excellent in cushioning property (shape returnability) and heat insulating property, and is used for cushioning materials and heat insulating materials. In the case where is a waste material, it is not recycled as disclosed in Japanese Patent Application Laid-Open No. Hei 9-137926, and most of the waste material is disposed in a landfill or the like.

[0005] The reason that the reuse of urethane foam waste material is more difficult than in the case of other synthetic resin materials is that urethane foam has a very low bulk density and is a flexible foam.

When urethane foam waste is to be reused as a raw material for a synthetic resin product, urethane foam has a very low bulk density and is a bulky substance. In addition to having to prepare them, handling operations and operations during reproduction processing become extremely inefficient.

When urethane foam waste is blown into a furnace such as a blast furnace to be used as a substitute for a raw material or fuel, a large amount of urethane foam must be formed into fine particles that can be transported by air. Also, when the particulate matter is pneumatically transported and blown into a furnace such as a blast furnace, since the particles of urethane foam are very light, the volume of the blown particles is several tens times that of the case where normal raw materials and fuel are blown. In addition, the particles of urethane foam stored in the storage tank are suspended on the shelf and do not drop, or the clogging of the pneumatic piping occurs, making it impossible to blow into the furnace body . Thus, since the urethane foam particles are very bulky, they cannot be efficiently blown.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a processing method for converting waste urethane foam into a state that can be reused as a resource. It is an object of the present invention to provide a method of supplying a furnace such as a blast furnace.

[0009]

Means for Solving the Problems In order to achieve the above object, in the method for shrinking urethane foam waste according to the first invention, the urethane foam waste is heated and softened.
It is kneaded by compression while being compressed, and then cooled and solidified.

In the shrinkage treatment method for urethane foam waste according to the second invention, when the urethane foam waste is heated and softened in the first invention, a thermoplastic resin is mixed in advance with the urethane foam waste. .

[0011] In the method for supplying urethane foam waste to a furnace according to the third invention, the urethane foam waste is heated and softened, kneaded while being compressed and shrunk, and the shrunken kneaded material is granulated. The particulate matter is transported by air stream and blown into a furnace.

In the method for supplying urethane foam waste to a furnace according to the fourth invention, when the urethane foam waste is heated and softened in the third invention, a thermoplastic resin is mixed with the urethane foam waste in advance. Keep it.

As described above, the urethane foam is very bulky and a flexible foam is one of the factors that hinder the reuse of waste materials. For this reason, the present inventors have studied to shrink this bulky urethane foam, and have reached the technology of the present invention.

If the foaming material is a thermoplastic resin, it melts when heated, and the foamed structure is destroyed and shrinks. However, since urethane foam is a thermosetting resin, it does not shrink simply by heating. However, the present inventors have paid attention to the fact that urethane foam has a property of temporarily softening when heated. That is, if the urethane foam is heated and softened and compressed, the foam shrinks. Further, if the kneading process is performed, the foamed structure is further broken and contracted. Then, by cooling in a contracted state, a solidified urethane resin can be obtained.

If the solidified product is crushed and granulated,
Since the particles are in the same state as ordinary resin, they can be used as a substitute for a raw material or fuel injected into a furnace such as a blast furnace.

When only the urethane foam waste is heated and shrunk, a brittle solidified substance is generated and easily collapsed in later handling. Therefore, the urethane foam waste is heated and softened as described above. At this time, it is preferable to mix a thermoplastic resin with urethane foam waste in advance. On this occasion,
Although the urethane foam only softens, the thermoplastic resin melts and the melt is mixed, so that the thermoplastic resin functions as a binder. For this reason, when this contracted material is solidified, a hardened material that is hard to break is obtained. When the shrinkable material is to be solidified after being molded, the moldability is improved by mixing a thermoplastic resin. As thermoplastic resins, polyethylene, polypropylene, polybutene, polystyrene, polyester, polyvinyl acetate,
Polyamide, a mixture thereof, a copolymer, or the like can be used.

[0017]

FIG. 1 is a view showing an example of a processing method for shrinking urethane foam waste material according to the present invention. First, in a heating step, urethane foam waste material cut to a predetermined size or less is heated and softened. At this time, if necessary, a thermoplastic resin is mixed at a predetermined ratio, and the thermoplastic resin is melted. Next, in the compression / kneading step, the softened urethane foam or a mixture of the urethane foam and the molten thermoplastic resin is kneaded while compressing while maintaining the heating temperature. The softened urethane foam is compressed and contracted. Furthermore, since urethane foam is kneaded and crushed simultaneously with compression, the foamed structure is destroyed and shrinks further. If the contracted product is cooled by an operation such as water spraying or submersion in a contracted state in the next cooling step, a solidified urethane resin is obtained.

Then, this solidified product is sent to a crushing step, if necessary, and crushed to a predetermined particle size to obtain a granular material.

When the solidified material is crushed into granules, and the granules are used as a substitute for a raw material or a fuel, the granules have a certain strength and become powdery during transportation. It is desirable not to do it. In such a case, the treatment is preferably performed by mixing a thermoplastic resin, and the mixing ratio is preferably 10% by weight (urethane foam: thermoplastic resin = 90: 10) or more. Mixing ratio is 10%
If it is less than the above, the strength of the solidified product is slightly insufficient.

The temperature of the heating step and the compression / kneading step may be at least the softening point of the urethane foam.
The range is about 360 ° C. However, if the temperature is raised more than necessary, there arises a problem that urethane foam is decomposed to generate toxic gas, or a highly tacky substance that does not solidify even when cooled is generated. Therefore, the upper limit of the heating temperature is 360
It needs to be about ℃.

FIG. 2 is a diagram showing an example of a processing method when an extruder is used for the heating step and the compression / kneading step in FIG. In this figure, a method of mixing a thermoplastic resin is shown, but the mixing of the thermoplastic resin is performed as needed.

In the processing method shown in FIG. 2, first, the urethane foam waste is reduced to a size of about 80 mm or less by a cutting machine 11, and the thermoplastic resin is crushed to a size of about 10 mm or less by a crusher 12. . Next, the cut urethane foam waste material and the crushed thermoplastic resin are each weighed by a predetermined amount, and the two treated materials are simultaneously charged into the hopper of the extruder 13. The two treated materials enter the cylinder from the hopper of the extruder 13, are stirred well by a screw, and are heated while being compressed. This heating softens the urethane foam and melts the thermoplastic resin. Then, the melt of the softened urethane foam and the thermoplastic resin is kneaded while being compressed by a screw while being kept at a predetermined temperature. In this kneading, a shearing force is applied to the processed material with the rotation of the screw, so that the foamed structure is destroyed. The kneaded and contracted treatment material is extruded from a die attached to the end of the cylinder, formed into a linear body, and discharged.

The molded product is cooled by a cooling device 14 provided with cooling means such as water spray, and becomes a solidified product. The solidified material is crushed by a crusher 15 so as to have a predetermined particle size. The granules are sieved as required and sent to the storage hopper 20.

When an extruder is used, there is an advantage that the kneading in the heating / kneading step is sufficiently performed, and in addition, the kneaded material can be formed into a shape such as a linear body. The crushing of the material is facilitated, and a granular material having a desired particle size can be efficiently obtained by appropriately adjusting the diameter of the molded product.

The extruder that can be used in the present invention is used for extruding or melt-spinning a synthetic resin, and may have a single screw or a twin screw. Also, the feed method of the processing material may be a normal method of charging from the top, but since the urethane foam processing material is light and bulky, a feed method of forcibly loading while compressing, It is better to improve the molding ability.

FIG. 3 is a diagram showing an example of a method for supplying urethane foam waste to a blast furnace as a substitute material for a carbon material. Predetermined amount of urethane foam waste material and thermoplastic resin,
For example, the waste urethane foam is sent to the granulating apparatus 10 configured as shown in FIG. 2 and granulated. Then, the particulate matter is sent to the storage hopper 20 to be temporarily stored, then sequentially extracted, introduced into the blowing hopper 21, and transported by a carrier gas in a gas stream to the blast furnace 30. At this time, the resin particles flow through the air supply pipe 22 and are introduced into the blow pipe 31 from a blow nozzle inserted into a blow pipe 31 for blowing air provided at the tuyere of the blast furnace 30 and blown into the furnace. It is.

When the particulate matter is blown into the furnace, the resin particles are decomposed to generate carbon monoxide and hydrogen gas to act as a reducing agent for iron ore, and to burn to generate heat of combustion. The charge therein is heated and melted, and the granular material is effectively used as a substitute for the carbon material.

[0028]

[Example] (Granulation test) An apparatus having the same configuration as the apparatus shown in FIG.
Various tests were carried out between 0 ° C and 380 ° C. At the same time, the presence or absence of a thermoplastic resin was also tested.

The urethane foam waste material having a size of about 30 mm or less is heated and kneaded by an extruder to form a molded product.
It was made into a linear body having a thickness of mm. At this time, in the test for adding the thermoplastic resin, the thermoplastic resin crushed to a size of about 6 mm or less was mixed. Next, after cooling and solidifying, it was crushed into particles. The test results are shown in Table 1.

In Table 1, in the column of the extruder, the number of screws and the diameter of the extruder used are described. Further, PE, PP and PS in the column of thermoplastic resin indicate polyethylene, polypropylene and polystyrene, respectively. In the evaluation column, は indicates that the shrinkage was sufficiently performed, は indicates that the shrinkage was sufficient, and that the moldability was good,
Indicates a case where urethane foam is decomposed, gas is generated, and a sticky substance is generated.

As shown in Table 1, the resin temperature was from 200 ° C.
When treated in the range of 360 ° C (No. 1 to No. 18)
Was able to be sufficiently shrunk, molded and granulated. However, when the resin temperature (set temperature) is 15
When the treatment was carried out at 0 ° C. (No. 21), it was impossible to extrude from the extruder due to insufficient softening.
Further, when the treatment was performed at a resin temperature exceeding 360 ° C., decomposition of the resin occurred. In addition, when a thermoplastic resin is added, it shrinks sufficiently and has good moldability,
A compact having a dense and smooth surface was obtained.

In the above test, after the contracted urethane foam waste material is solidified and then granulated, the urethane foam waste material is treated as a raw material for a synthetic resin product. It is not necessary to granulate.

[0033]

[Table 1]

(Blowing test into blast furnace) Waste urethane foam and polyethylene were introduced into a granulating apparatus having the same configuration as that shown in FIG. 2 and subjected to heating, kneading, molding, cooling, and crushing processes, and were subjected to a process of about 6 mm. Granules. At this time, polyethylene was mixed with waste urethane foam at a ratio of 80:20. Next, the particulate matter was temporarily stored in a storage hopper, sent to a blowing hopper, air-transported under the following conditions, and blown from a blowing nozzle into a tuyere of a blast furnace via a blow pipe.

Blowing conditions Carrier gas: air Blowing amount of synthetic resin granules: 60 kg / min Carrier gas flow rate: 1200 Nm ³ / hr The operating conditions of the blast furnace were as follows, and simultaneously from other tuyeres. Pulverized coal was also injected.

Operating conditions of the blast furnace Blast output: 9000 t / d Coke ratio: 447 kg / t- pig iron Blow rate: 7260 Nm ³ / min Oxygen enrichment rate: 4 vol% Blast temperature: 1200 ° C. Synthesis under the above conditions The resin granules were blown in for 8 hours, but no troubles such as storage hoppers and blow hoppers hanging on the shelves or clogging of the pneumatic piping system occurred, and smooth operation could be continued. .

[0037]

According to the method for shrinking urethane foam waste according to the present invention, since the urethane foam waste is heated and softened to be compressed and kneaded, the foamed structure is destroyed and shrinks. For this reason, it is possible to obtain a solidified material that can be reused.

In the method for supplying urethane foam waste material to the furnace according to the present invention, the urethane foam waste material is heated, softened, compressed and kneaded, shrinked, and the solidified product is granulated. Since the particles are pneumatically transported and blown into the furnace, troubles such as clogging of the pneumatic tube system do not occur, and the supply of the blowing material is performed smoothly.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a processing method for shrinking urethane foam waste material according to the present invention.

FIG. 2 is a diagram showing an example of a processing method when an extruder is used for the heating step and the compression / kneading step in FIG.

FIG. 3 is a diagram showing an example of a method of supplying urethane foam waste material to a blast furnace as a substitute material for a carbon material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Granulation apparatus 11 Cutting machine 12 Crusher 13 Extruder 14 Cooling device 15 Crusher 20 Storage hopper 21 Blow hopper 30 Blast furnace 31 Blow pipe

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B29K 105: 04 105: 26 (72) Inventor Yukihiko Asakawa 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd.

Claims (4)

[Claims] 1. Heating and softening urethane foam waste material,
A method of shrinking urethane foam waste material, which comprises kneading and shrinking while compressing, and then cooling and solidifying. 2. The shrinkage treatment method for urethane foam waste according to claim 1, wherein the thermoplastic urethane foam is mixed with a thermoplastic resin before heating and softening the urethane foam waste. 3. Heating and softening the urethane foam waste material,
A method of supplying urethane foam waste material to a furnace, which comprises kneading and shrinking while compressing, granulating the shrunken kneaded material, and air-transporting the granulated material into a furnace. 4. The urethane foam waste according to claim 3, wherein the thermoplastic urethane foam is mixed with a thermoplastic resin before heating and softening the urethane foam waste. Method.