JPH07100832A - Microwave thermal decomposition furnace - Google Patents

Abstract

PURPOSE:To make it possible to discharge a plastic applied to a metal as a coat by thermally decomposing the plastic with a concurrent procedure to prevent the metal from becoming thermally deformed. CONSTITUTION:This microwave thermal decomposition furnace is composed of a composition furnace 2 for storing a plastic-coated material 1 such as an automotive steering wheel coated with polyurethane or a plastic containing polyurethane applied to a metal through an adhesive, a microwave oscillator 3 for irradiating the plastic-covered material 2 with a microwave to heat the plastic, and thermally decomposing the plastic and the adhesive, and at least, one pair of discharge rollers 5 provided at the lower part of an applicator 6 storing the decomposition furnace 2 and discharging the plastic. Consequently, it is possible to realize this concept ranging from the thermal decomposition to the discharge of the plastic into an actual device and at the same time, increase the processing capacity and make the operation easy.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, defective products of plastic coatings such as steering wheels for vehicles, which have occurred in the production stage, swelled by knurling 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 the surface of the cored bar is finally polished with a wire brush to recover the cored bar made of aluminum or iron. Due to such manual work, the processing capacity of the peeling means is extremely limited. As alternative means, there are thermal decomposition means and high frequency heating means, but in both cases the temperature does not rise too high and the plastic is not decomposed in a short time and is exposed to higher temperatures than necessary. There is a risk that aluminum may partially melt or iron may be thermally deformed.

Further, there has been proposed a microwave thermal decomposition furnace in which a plastic coating is heated by irradiating microwaves to thermally decompose the plastic to flow down a lattice-shaped separator and discharge it. This furnace has a simple discharge structure and is economically advantageous, but since the pyrolyzed plastic is made into a dry state with less stickiness, temperature control becomes complicated when changing the atmospheric temperature during pyrolysis and during discharge. There is a fear.

[0004]

In the conventional means for thermally decomposing plastics, the metal body is partially melted in order to decompose and remove the plastic from the plastic coating while keeping the ambient temperature at a considerably high temperature. There was a problem of thermal deformation. Further, in the apparatus for thermally decomposing the plastic coated on the metal body by irradiating with microwaves, there is a problem that the atmospheric temperature control becomes complicated because it is in a state in which it is easily discharged and has a low adhesiveness.

An object of the present invention is to provide a microwave thermal decomposition furnace capable of preventing thermal deformation of a metal body and thermally decomposing the plastic covered with the metal body, and easily discharging the plastic even in a highly adhesive state. To provide.

[0006]

In order to achieve the above-mentioned object, a microwave heating decomposition furnace according to the present invention is a plastic coating in which a metal body is coated with polyurethane or a plastic containing polyurethane through an adhesive. Decomposition furnace that accommodates, a microwave oscillator that irradiates microwaves to the decomposition furnace to heat the plastic coating to thermally decompose the plastic and adhesive, and the pyrolysis plastic that is installed in parallel at the bottom of the decomposition furnace. And at least a pair of discharge rollers.

[0007]

According to the present invention, since the plastic itself absorbs microwaves to generate heat when irradiated with microwaves, only the plastics are heated to a predetermined temperature and the metal body is not exposed to an unnecessarily high temperature atmosphere. . Moreover, heating is started and stopped instantaneously, and temperature control is easy. The plastic begins to decompose and melt due to heating, and falls off from the metal body.However, since a pair of discharge rollers are installed at the bottom of the decomposition furnace and rotate in opposite directions, even if the removed and removed plastic has a high adhesiveness The discharge wave is forcibly sent out by being sandwiched between the discharge rollers, and the microwave is attenuated to a greater extent than between the pair of discharge rollers. Therefore, the plastic accumulated under the pair of discharge rollers is not subjected to excessive thermal decomposition, and the microwave is not consumed unnecessarily.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An 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 steering for a vehicle, which is covered with polyurethane or plastic containing polyurethane through an adhesive on a metal body, and microwaves are irradiated to the decomposition furnace 2. And a microwave oscillator 3 for thermally decomposing the plastic and the adhesive to thermally decompose the plastic and the adhesive, and at least a pair of discharge rollers 5 provided below the decomposition furnace 2 for delivering the thermally decomposed plastic. It is a composition.

The decomposition furnace 2 is housed in an applicator 6,
The microwave oscillator 3 is installed on the upper portion of the applicator 6 by the waveguide 7
Connected via. A carbon dioxide gas inlet 8 is provided at the bottom of the applicator 6, and a gas outlet 14 for discharging the generated gas is provided at the top of the applicator 6. A pair of discharge rollers 5 are rotatably disposed below the decomposition furnace 2 via a skirt 9, and a falling object accumulation chamber 11 mounted on a guide rail 10 is detachably provided below the applicator 6. . A plurality of plastic coatings 1 are vertically inserted through a shaft 12 to be stacked and housed in a decomposition furnace 2, and the lower end of the shaft 12 is connected to a motor (not shown) and rotated.

As shown in FIGS. 1 to 3, the pair of discharge rollers 5 are formed in a cylindrical shape and are arranged side by side with their longitudinal directions horizontal, and a plurality of protrusions 13 are arranged in the horizontal direction at a predetermined pitch. One end in the horizontal direction is connected to the drive motor 15 provided outside the applicator 6 via the gear mechanism 16. An opening / closing door for inspecting and maintaining the discharge roller 5 is provided on the other end side in the horizontal direction. A pair of discharge rollers 5
Are arranged substantially parallel to each other with a clearance such that the protrusions 13 do not contact each other, and one of the discharge rollers 5 rotates in the clockwise direction and the other discharge roller 5 rotates in the counterclockwise direction. A scraper 17 having a knife-shaped upper end is provided between the protrusions 13 in a protruding manner. As the material of the discharge roller 5, a material that does not absorb microwaves and has heat resistance of 200 ° C. or higher, such as paramagnetic 18Cr8Ni stainless steel, is suitable. In addition, it is important to set a gap so that microwaves do not pass through between the pair of discharge rollers 5 or between the inner wall of the applicator 6 and the thermally decomposed plastic can be sufficiently discharged. Since the amount of microwave leakage is proportional to the ratio of the area of the gap to the bottom area of the entire cracking furnace, reducing the gap makes the leakage almost unaffected.

Next, the operation of this embodiment will be described. Decomposition furnace 2
While rotating a plurality of plastic coatings (vehicle steering wheel) 1 housed in the vehicle by a motor (not shown), the microwave oscillator 3 irradiates microwaves of about 2450 MHz by controlling the control means (not shown). The microwaves enter the inside of the applicator 6 from the upper center through the waveguide 7, are uniformly dispersed, and are absorbed by the plastic. At this time, the plastic coating 1 is rotated at a low speed to uniformly absorb microwaves, and carbon dioxide or an inert gas as a sealing gas is circulated in the decomposition furnace 2 at 30 liter / min. Atmosphere temperature of decomposition furnace 2
By controlling the temperature to ˜500 ° C., the plastic drops in an annular shape in about 20 minutes and adheres to the upper surfaces of the pair of discharge rollers 5. Since the discharge rollers 5 rotate in opposite directions to each other, plastic is caught between the discharge rollers 5, and even plastic having high adhesiveness passes through the gaps between the protrusions 13 and is forced to flow downward. , Falling object collection room 11
Accumulated in. Microwaves penetrate to a depth of about 50 mm, but the microwaves do not penetrate to the falling object accumulation chamber 11, the microwaves are not unnecessarily consumed, and the plastic accumulated in the falling object accumulation chamber 11 becomes Problems such as gasification due to excessive irradiation of waves can be prevented. Then, the falling object accumulation chamber 11 is removed from the applicator 6, moves on the guide rail 10 and can be easily carried out to the outside, and the plastic can be discarded and incinerated.
A water jacket 18 may be provided inside the discharge roller 5, the bearing cooling water may be circulated to cool the discharge roller 5, and the adhesiveness of the plastic may be adjusted by changing the temperature of the plastic. The metal body can be easily recovered by opening a part of the applicator.

Another embodiment of the present invention is shown in FIG. 1 differs from the embodiment shown in FIG. 1 in that pyrolyzed plastic is conveyed by a conveyor 19 and a pair of discharge rollers 5 located therebelow have no protrusions and are arranged side by side through a predetermined gap. And they are rotating in reverse. Further, the falling object accumulation chamber 11 is detachably connected to the lower end of the applicator 6, and when the pyrolyzed plastic is accumulated, the falling object accumulation chamber 11 is removed from the applicator 6 and moved to the outside by a trolley 18 with a lift. This is a possible configuration. With this configuration, the same operation and effect as those of the embodiment shown in FIG. 1 can be obtained.

[0013]

According to the present invention, the plastic coated on the metal body is pyrolyzed by microwaves, so that the metal body is prevented from being thermally deformed, and the device can be made into a device. The rotation of the discharge roller allows forcible discharge, which has the effects of increasing the processing capacity of the plastic coating and facilitating operation.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

2 is a cross-sectional view of FIG.

3 is a side view showing the discharge roller of FIG. 1. FIG.

FIG. 4 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plastic coating 2 Decomposition furnace 3 Microwave oscillator 5 Discharge roller 6 Applicator 7 Waveguide 8 Carbon dioxide gas inlet 9 Skirt 10 Guide rail 11 Falling object accumulation chamber 12 Shaft 13 Protrusion 14 Gas outlet 15 Drive motor 16 Gear mechanism 17 Scraper

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C08J 11/12 CFF 7310-4F ZAB 7310-4F // B29K 75:00 105: 26 C08L 75:04 H05B 6/80 A (72) Inventor Yukio Nakamura 1st Yawata Kaigan Dori, Ichihara City, Chiba Mitsui Engineering & Shipbuilding Co., Ltd. Chiba Works (72) Inventor Junichiro Shimizu 1 Hachiman Kaido Dori, Ichihara, Chiba Mitsui Engineering & Ships Co., Ltd. Chiba Business (72) Inventor Toshiro Inomata 1st Hachiman Kaigan Dori, Ichihara, Chiba Mitsui Engineering & Shipbuilding Co., Ltd. Chiba Works (72) Inventor Yoshiaki Matsumoto 1st Hachiman Kaigan Dori, Ichihara, Chiba Mitsui Engineering & Ships Co., Ltd. Chiba Works (72) Inventor Kazuo Sato 5-6-4 Tsukiji, Chuo-ku, Tokyo Mitsui Shipbuilding Co., Ltd. (72) Inventor Tokatsu Togawa Aichi Kasuga-machi, Kasuga-cho, Ochiai, Nagahata, 1st place, Toyoda Gosei Co., Ltd. (72) Inventor, Masahiro Takimoto, Nishi Kasugai-gun, Kasuga-cho, Ochiai, Nagahata, Toyoda Gosei, (72) Inventor, Toshio Hayashi Nishi Kasugai, Aichi Kasugacho Ochiai character Nagahata No. 1 Toyota Gosei Co., Ltd.

Claims (1)

[Claims] 1. A decomposition furnace containing a plastic coating coated with polyurethane or a plastic containing polyurethane through an adhesive on a metal body, and heating the plastic coating by irradiating the decomposition furnace with microwaves. A microwave oscillator that thermally decomposes the plastic and the adhesive, and at least a pair of discharge rollers that are arranged in parallel in the lower part of the decomposition furnace and that discharges the thermally decomposed plastic. Thermal decomposition furnace.