JP3304546B2 - Microwave pyrolysis furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the recovery of a metal core (metal body) such as a steering wheel for a vehicle, which is coated with polyurethane or plastic, and is particularly suitable for recovering a metal body by thermally decomposing plastic. The present invention relates to a microwave pyrolysis furnace.

[0002]

2. Description of the Related Art Conventionally, defective plastic coatings such as a steering wheel for a vehicle generated in a production stage are swollen by cutting a knife in a plastic such as polyurethane as a coating material and immersing them in an organic solvent overnight. The plastic is scraped off with a knife, and finally the surface of the metal core is polished and finished with a wire brush to collect the aluminum or iron metal core. Such manual work severely limits the processing capacity of the stripping means. As alternative means, there are thermal decomposition means and high-frequency heating means.However, unless the ambient temperature is set to a considerably high temperature, the plastic does not thermally decompose in a short time and is exposed to an excessively high temperature. There is a possibility that aluminum partially melts or iron is thermally deformed. Japanese Patent Application Laid-Open No. 61-70315 discloses an apparatus for thermally treating plastic waste by microwaves and detecting the temperature to control the amount of air supply and the amount of waste supplied. The document does not disclose a device for processing a plastic of a coating material and recovering a metal body, and does not disclose a detailed structure of an incinerator, particularly, a plastic discharging mechanism. The plastic that has been pyrolyzed and accumulated may be subject to excessive irradiation of microwaves to generate gas, which may result in unnecessary consumption of microwaves.

[0003]

In the conventional plastic pyrolysis means, since the plastic is thermally decomposed and removed from the plastic coating while maintaining the ambient temperature at a considerably high temperature, the metal body is partially melted. And there was a problem of thermal deformation. Further, in an apparatus for thermally decomposing plastic by irradiating microwaves, there is a problem in that accumulated plastics generate gas due to excessive irradiation of microwaves, and microwaves are unnecessarily consumed.

An object of the present invention is to provide a microwave pyrolysis furnace capable of thermally decomposing and discharging plastic coated on a metal body while preventing thermal deformation of the metal body.

[0005]

In order to achieve the above-mentioned object, a microwave pyrolysis furnace according to the present invention comprises a plastic coating comprising a metal body coated with polyurethane or a plastic containing polyurethane via an adhesive. comprising a cracking furnace for acquisition, and thermally decomposing the microwave oscillator the plastic and the adhesive is irradiated with microwaves in the cracking furnace to heat the plastics <br/> stick coating, said cracking furnace
At the bottom of the grid is a grid that discharges pyrolyzed plastic
A separator is provided .

[0006]

[0007]

According to the present invention, the plastic itself absorbs microwaves and generates heat when irradiated with microwaves, so that only the plastic coating is heated to a predetermined temperature and is not exposed to an unnecessarily high temperature atmosphere. In addition, heating start and stop are instantaneously performed, and temperature control is easy. Heating causes the plastic to begin to decompose and melt and fall off the metal body. Further, since the grid-like separator is provided at the lower part of the cracking furnace, the plastic that has fallen off and falls through the small holes, and the microwave does not pass through the small holes. Therefore, the plastic accumulated under the lattice separator does not undergo excessive thermal decomposition, and microwaves are not unnecessarily consumed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, a decomposition furnace 2 for accommodating a plastic coating 1 such as a vehicle steering wheel or the like in which a metal body is coated with polyurethane or a plastic containing polyurethane via an adhesive, and the decomposition furnace 2 is irradiated with microwaves. To heat the plastic coating 1 to thermally decompose the plastic and the adhesive, and a grid-like separator provided at the lower part of the decomposition furnace 2 and having a plurality of small holes 4 for flowing down the thermally decomposed plastic ( (Microwave cut separator) 5 and an applicator 6 for accommodating the decomposition furnace 2 and the grid separator 5.

The decomposition furnace 2 is housed in an applicator 6,
The microwave oscillator 3 has a waveguide 7 on the upper part of the applicator 6.
Connected via A carbon dioxide gas inlet 8 is provided at the bottom of the applicator 6, and a gas outlet 14 for discharging generated gas is provided at an upper side surface of the applicator 6. The lower periphery of the applicator 6 is supported by a brick 9, the lower end of the separator 5, the brick 9 and the applicator bottom plate 1.
0, a falling object accumulation chamber 11 is formed. A plurality of plastic coatings 1 are vertically
2 are housed in the decomposition furnace 2 and the lower end of the shaft 12 is connected to a motor 13 provided in the falling object accumulation chamber 11 so as to be rotatable.

As shown in FIGS. 2 to 4, the honeycomb-shaped grid separator 5 has a small hole 4 having a polygonal, preferably regular hexagonal, cross-sectional shape and a depth F of 50 to 200 mm and preferably 150 mm. , The major axis D is about 5 mm, the partition plate 15 of the small hole 4
Has a thickness of 0.5 to 1.0 mm, preferably 1 mm. As the material of the lattice separator 5, a material that does not absorb microwaves and has heat resistance of 200 ° C. or more, for example, paramagnetic 18Cr8Ni stainless steel is suitable.

It is important that the grid-like separator 5 has such a structure that even if the dropped plastic adheres to the upper surface, it is decomposed by the microwave to flow down the small holes and the microwave does not pass through the separator.

Next, the operation of this embodiment will be described. Decomposition furnace 2
While rotating a plurality of plastic coatings (vehicle steering wheel) 1 accommodated in the motor 1 by a motor 13, microwaves of about 2450 MHz are controlled by a microwave oscillator 3 and irradiated by control means (not shown). Microwaves enter the interior of the applicator 6 through the waveguide 7 from the top center and are uniformly dispersed and absorbed by the plastic. At this time, the plastic coating 1 is rotated at a low speed to absorb uniform microwaves, and a carbon dioxide gas or an inert gas is circulated as a seal gas into the cracking furnace 2 at a rate of 30 liter / min. The atmospheric temperature of the cracking furnace 2 is 300 to
By controlling the temperature to 500 ° C., the plastic falls in a ring shape in about 20 minutes and adheres to the upper surface of the grid-like separator 5, but the ambient temperature is controlled to a predetermined temperature different from that at the time of thermal decomposition as necessary. As a result, the fallen plastic is put into a dry and dry state, and flows down the small holes 4 and is accumulated in the falling object accumulation chamber 11. About 50 of small hole 4
Although the microwave enters to a depth of mm, the microwave does not penetrate to the falling object accumulation chamber 11 and the microwave is not consumed unnecessarily, and the plastic accumulated in the falling object accumulation chamber 11 irradiates the microwave. Thus, problems such as gasification can be prevented. The accumulated plastic is made rotatable, for example, by rotating the applicator bottom plate 10. The plastic is received on the aluminum foil laid on the upper surface, and can be easily discharged to the outside together with the aluminum foil, and can be discarded and incinerated. The metal body can be easily recovered by opening a part of the applicator. In the present embodiment, it is important to control the temperature of the atmosphere in the decomposition furnace so that the plastic is decomposed from a state in which the plastic has a high tackiness to a state in which the plastic has a low tackiness and is easy to handle.

[0013]

According to the present invention, the plastic coated on the metal body is thermally decomposed by microwaves, so that the metal body is prevented from being thermally deformed, the apparatus can be implemented, and the thermally decomposed plastic can be easily removed. There is an effect that discharge can be performed, the processing capacity of the plastic coating increases, and the driving operation becomes easy.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

FIG. 2 is a plan view showing the grid separator of FIG. 1;

FIG. 3 is a sectional view of FIG. 2;

FIG. 4 is a partial perspective view of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plastic coating 2 Decomposition furnace 3 Microwave oscillator 4 Small hole 5 Lattice separator 6 Applicator 7 Waveguide 8 Carbon dioxide gas inlet 9 Brick 10 Applicator bottom plate 11 Falling object accumulation room 12 Axis 13 Motor 14 Gas outlet

────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI B29K 75:00 C08L 75:04 C08L 75:04 B09B 3/00 303A 303E (72) Inventor Kazuo Sato 5-chome Tsukiji, Chuo-ku, Tokyo No. 6-4 Mitsui Engineering & Shipbuilding Co., Ltd. (72) Inventor Toshiro Inomata 1 Yawata Kaigan-dori, Ichihara City, Chiba Prefecture Mitsui Engineering & Shipbuilding Co., Ltd. Chiba Works (72) Inventor Tokatsu Togawa Kasuga-cho, Aichi Prefecture No. 1 Toyoda Gosei Co., Ltd. (72) Inventor Masahiro Takimoto Aichi Prefecture, Kasuga-cho, Nishi-Kasugai-gun, Ojiai, Nagahata 1 No. 1 Toyoda Gosei Co., Ltd. (56) References JP-A-56-87715 (JP, A) JP-A-54-56680 (JP, A) Flat 5-138799 (JP, A) (58 ) investigated the field (Int.Cl. ^7, DB name) B29B 17/00 - 17/02 C08J 11/00 - 11/28 B09B 3/00 - 5/00

Claims (1)

(57) [Claims] (1) A polyurethane or a metal body is bonded to a metal body via an adhesive.
Is a plastic-coated plastic
A cracking furnace for accommodating the plastic coating;
Heating the plastic coating by irradiating black light;
Microwave generator for pyrolyzing plastic and the adhesive
And a vibrator, the bottom of the decomposition furnace, features and to luma microwave pyrolysis furnace in that a grid-like separator for discharging the pyrolyzed plastic.