JP2003113413A - Recycling method for scrapped automobile or electric appliance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recycle scrapped large numbers of automobiles and electric appliances as iron sources without shredding them. SOLUTION: Melt pressed scrap of the unshredded scrapped automobiles or electric appliances is used as a raw material 16, by using a melting apparatus 1 having a melting chamber 2 with a heat source 19 and a shaft type of a combustion chamber 3 directly connected to the melting chamber. A recycling method comprises melting the pressed scrap of the scrapped automobiles or the electric appliances in the melting chamber with the heat source, while supplying the pressed scrap of scrapped automobiles of the electric appliances to the combustion chamber, so as to maintain a state that a space for exhaust gas to burn and raise the temperature is secured in the upper part of the combustion chamber as well as to maintain a state that the unmelted pressed scrap of waste automobiles or the waste electrical household appliances exists in the melting chamber and the lower part of the combustion chamber, and tapping a molten metal 17 when its predetermined amounts are stored in the melting chamber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recycling used automobiles or used electric appliances such as refrigerators and washing machines, and more specifically, to shred used automobiles or used electric appliances. Instead, it relates to a method of recycling as an iron source.

[0002]

2. Description of the Related Art Conventionally, used automobiles are pressed after removing valuable parts such as batteries and tires, shredded after pressing, and reused as iron scraps. During this shredder processing, shredder dust containing plastic, rubber, iron, aluminum, copper, etc. is generated. Approximately 200 kg of shredder dust is generated by shredder processing of one used car of about 1 ton, and about 800,000 ton of shredder dust is generated annually from used cars in Japan. Similarly, used home appliances are shredded after removing the motor, coolant, etc.
0,000 tons of shredder dust is generated from used home appliances. This shredder dust is either landfilled or burned and melted in a waste incinerator.

The landfill disposal requires a large amount of disposal cost because the disposal site is limited, and in the combustion treatment by the incinerator, the ash content and the metal content in the shredder dust remain, and this disposal becomes a problem. Further, in the method of directly gasifying the shredder dust and directly melting the incombustible content, a molten metal containing iron and copper as main components is produced, and this is used as a counterweight after solidification, but the amount used is limited. Yes, the disposal of this bullion becomes a problem.

On the other hand, used automobiles (hereinafter also referred to as "waste cars") are not shredded, and used automobile scraps (hereinafter referred to as "waste car press scraps") are directly processed in a steelmaking melting furnace typified by a converter. The dissolution method is disclosed in JP-A-10-33.
It is proposed in Japanese Patent No. 0821. According to this method
No shredder dust is generated, and plastic, rubber, etc. also serve as a heat source during melting, and scrap car scraps can be efficiently melted. However, this method has a limit to the amount of scrap scraps that can be dissolved. That is, according to the same publication, the amount of scrap scraps of scrap cars that can be loaded into a 250 ton converter can be up to 15 tons (heat scrap: about 10 cars) per heat because of the steel composition. Due to problems such as the method of charging scrap into the furnace and smoke generation during charging, the limit is actually about four scrap cars per heat.

Although it is naturally conceivable to directly insert scrap scraps into an arc melting facility (electric furnace), scrap scraps are large in size (about 0.8 m × 0.8 m × 1.3 m). Since the bulk density of the arc melting equipment is small, it is necessary to open and close the upper lid of the melting chamber every time when scrap car press waste is charged in the normal arc melting equipment.From the viewpoint of productivity of the arc melting equipment and environmental measures, arc melting equipment There is a natural limit to charging equipment.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The number of disused cars generated in Japan is about 5 million per year, and the diffusion rate of home electric appliances may increase, but it will not stagnate. In addition, it is impossible to recycle such a large amount of used automobiles and used home appliances with a conventional technology without shredding with a converter or arc melting facility which is a typical steelmaking melting facility. is there.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a method for recycling used automobiles and used home appliances that generate a large amount as an iron source without shredding, that is, without generating shredder dust.

[0008]

The method for recycling used automobiles or used home appliances according to the first aspect of the present invention includes a melting chamber having a heating source and a shaft-type combustion chamber directly connected to the melting chamber. When melting scrap car press scraps or waste home appliance scraps obtained without shredding from used automobiles or used home appliances using a melting facility as melting raw material, In order to maintain the state existing in the melting chamber and the lower part of the combustion chamber, and to maintain the state in which the space for combustion of the exhaust gas to raise the temperature is secured on the upper side of the combustion chamber, scrap car press scraps or waste home appliances are put into the combustion chamber It is characterized in that scrap car press scraps or waste home appliance scraps in the melting chamber are melted by the heating source while supplying scraps, and the molten metal is discharged when a predetermined amount of melt is generated in the melting chamber.

The method for recycling used automobiles or used household appliances according to the second aspect of the present invention is the method of the first aspect, wherein oxygen-containing gas is supplied into the melting chamber and combustibles contained in scraps of scraps of used cars or scraps of household appliances. It is characterized in that it promotes gasification and combustion of a substance.

According to a third aspect of the present invention, there is provided a method for recycling used automobiles or used home appliances according to the first aspect or the second aspect, wherein an oxygen-containing gas is supplied to the upper space of the combustion chamber to press a waste vehicle. It is characterized by burning a combustible gas generated from scraps or waste home appliances scraps.

According to a fourth aspect of the present invention, there is provided a method for recycling used automobiles or used home appliances according to the second or third aspect, wherein the supply amount of the oxygen-containing gas is adjusted and the exhaust gas temperature at the outlet of the combustion chamber is adjusted. Keep above 1000 ℃,
In addition, it is characterized in that flammable gas remains in the exhaust gas at the outlet of the combustion chamber.

According to a fifth aspect of the present invention, there is provided a method for recycling used automobiles or used home appliances according to the fourth aspect, wherein the flammable gas is burned in a secondary combustion chamber provided downstream of the combustion chamber, The exhaust gas temperature is kept at 850 ° C. or higher, and then the exhaust gas is rapidly cooled to 250 ° C. or lower in a cooling chamber provided on the downstream side of the secondary combustion chamber.

According to a sixth aspect of the present invention, there is provided a method for recycling used automobiles or used home appliances according to any one of the first to sixth aspects, wherein the heating source is arc heating. Is.

In the first aspect of the present invention, when the waste car press scraps or the waste home electric appliance scraps obtained from the used automobiles or the used home electric appliances without the shredder treatment are dissolved as the melting raw material, the undissolved waste car press scraps or Waste household electrical appliances are continuously present in the melting chamber and the lower part of the combustion chamber, and in the upper part of the combustion chamber,
In order to maintain a state where there is no dissolved raw material and a space for combustion of exhaust gas to raise the temperature is maintained, scraps of scrapped cars or scraps of scraps of scrapped electric cars are placed on top of undissolved scraps of scrapped automobiles or scraps of household appliances that exist in the lower part of the combustion chamber. Alternatively, since the waste electric home appliances wastes are melted while being charged, a large amount of waste car press wastes and waste home electric appliances wastes can be continuously dissolved. For example, the entire amount of scraps of scrap car press can be dissolved. In this case, scrap car press scraps and waste home electric appliance scraps are not directly charged into the molten metal in the melting chamber, but are put on unmelted scrap car press scraps or waste home electric appliance scraps, and are preheated with exhaust gas before being melted. As it is supplied, the volatilization and combustion of combustibles contained in scrap car press scraps and waste home electric appliance scraps gradually progresses during this preheating, and the rapid combustion and combustion when the scrap car press scraps and waste home electric appliance scraps are immersed in the molten metal It is possible to prevent smoking. That is, a large number of used automobiles or used home appliances can be recycled as an iron source without shredding.

In the second aspect of the present invention, the oxygen-containing gas is supplied into the melting chamber to promote the gasification and combustion of the combustibles contained in the waste car press scraps or waste home appliance scraps in the melting chamber and the lower part of the combustion chamber. It is possible to further prevent sudden combustion and smoke generation when the scraps and waste home appliances scraps are immersed in the molten metal,
As a result, the amount of generated gas is leveled, and stable melting operation can be performed.

In the third aspect of the invention, the oxygen-containing gas is supplied to the upper space of the combustion chamber to burn the combustible gas generated from scraps of scrapped electric cars or scraps of household electric appliances, so that the exhaust gas temperature can be maintained at a high temperature. The decomposition of dioxins contained in the exhaust gas can be promoted.

In the fourth invention, the supply amount of the oxygen-containing gas is adjusted to keep the exhaust gas temperature at 1000 ° C. or higher, so that not only the decomposition of dioxins but also the synthetic resins contained in the scraps of scrapped automobiles or scraps of household electric appliances. The tar-based composition produced by gasification of rubber or rubber can also be decomposed, the tar-based composition can be prevented from adhering to a melting facility such as a duct, and stable melting operation can be performed. Further, in the fourth aspect of the invention, since the combustible gas remains in the exhaust gas at the outlet of the combustion chamber, the combustible gas can be effectively used as fuel in the exhaust gas treatment facility at the subsequent stage.

In the fifth aspect of the invention, the unburned combustible gas is burned in the secondary combustion chamber provided on the downstream side of the combustion chamber to keep the exhaust gas temperature at 850 ° C. or higher, so that the decomposition of dioxins is continued. Since the concentration of dioxins in the exhaust gas can be made extremely low, and after that, the exhaust gas is rapidly cooled to 250 ° C or less in the cooling chamber provided on the downstream side of the secondary combustion chamber. Synthesis can be prevented, and the concentration of dioxins in exhaust gas can be made extremely low.

In the sixth aspect of the invention, since arc heating is used as the heating source, the amount of heating and the heating rate can be easily controlled, and scraps of scraps of pressed cars or scraps of household electric appliances can be quickly and stably melted.

In the present invention, the scrap car press waste is
Used automobiles from which valuable parts such as batteries and tires have been removed have been pressed or cut after pressing.Waste home appliances scraps are used home appliances from which parts such as coolant have to be removed. If there is no portion to be removed before or after pressing the equipment, the shape of the waste home electric appliance may be the same. Since the outer shell of a home electric appliance has a rectangular parallelepiped shape, and if the size of the home electric appliance is large, most of the home electric appliance can be dissolved in the recycling treatment method of the present invention even if the size is the same, use In the case of a completed home electric appliance, it is preferable to melt it in its shape without pressing it from the viewpoint of reducing the pressing cost.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a diagram showing an example of an embodiment of the present invention, and is a schematic vertical cross-sectional view of an arc melting facility according to the present invention. FIG. 2 is a schematic plan view of the arc melting facility shown in FIG. 3 is a schematic diagram of an exhaust gas treatment facility connected to the arc melting facility shown in FIG. 1.

In FIGS. 1 and 2, a shaft-shaped combustion chamber 3 and a side wall 4 of a water-cooling structure are arranged above a melting chamber 2 having a refractory inside and a bottom electrode 6 at the bottom. The upper opening of the side wall portion 4 is covered with the upper lid 5 of the water cooling structure which can be opened and closed. An upper electrode 7 made of graphite is provided which penetrates the upper lid 5 and is vertically movable into the melting chamber 2. The bottom electrode 6 and the top electrode 7 are connected to a DC power source (not shown), and an arc 19 serving as a heating source is generated between the bottom electrode 6 and the top electrode 7.

Above the combustion chamber 3, a bottom opening type supply bucket 1 for supplying scrap car press scraps or scraps of household electric appliances obtained without performing shredder processing as a melting raw material 16.
5 is suspended from the traveling carriage 11 and the supply bucket 15 opens and closes the opening / closing lid 20 and the opening / closing lid 20a provided on the upper part of the combustion chamber 3 to scrap scrap automobile waste or scrap household electric appliances. Is charged into the combustion chamber 3 as a melting raw material 16. Exhaust gas generated in the melting chamber 2 by alternately opening and closing the open / close lid 20 and the open / close lid 20a when charging the melting raw material 16, that is, by closing one of the open / close lids 20 and 20a. Can be prevented from leaking.

As the melting raw material 16, as described above, scrap car press scraps obtained from used automobiles without shredding treatment, or waste home electric appliance scraps obtained from used home electric appliances without shredding treatment. I will use it.
However, in addition to these, other cold iron sources such as ordinary iron scrap or cold iron and direct reduced iron may be used as the melting raw material 16. FIG. 1 shows a case where scrap car press waste is used as the melting raw material 16.

A large amount of copper members are arranged as conductive materials in automobiles and home electric appliances, and since these copper members are the main cause of increasing the copper concentration of the molten metal 17 after melting, used automobiles and used home appliances The copper member may be removed from the device in advance and then scrapped. At that time, by removing 80% or more of the copper members constituting the automobile and the home electric appliances in advance, the copper concentration of the molten metal 17 to be generated is 0.3.
It can be suppressed to 5 mass% or less, and the copper concentration standard is 0.3.
It can be used as an iron source for steel products of 5 mass% or less.

An oxygen-containing gas supply lance 8 is provided penetrating the upper lid 5, and the oxygen-containing gas is melted in the melting chamber 2 in order to accelerate gasification and combustion of combustible substances contained in scraps of scraps of pressed cars and scraps of household electric appliances. It is blown inside. Air, oxygen-enriched air, and pure oxygen can be used as the oxygen-containing gas.

Further, the oxygen-containing gas supply port 9 is provided on the side wall of the combustion chamber 3 above the position where the molten raw material 16 is charged.
Is provided, and an oxygen-containing gas is blown into the combustion chamber 3 in order to control the exhaust gas composition and the exhaust gas temperature at the outlet of the combustion chamber 3. Thus, the combustion chamber 3 has both the function of supplying the melting raw material 16 into the melting chamber 2 and the function of adjusting the composition and temperature of the exhaust gas generated in the melting chamber 2.

A pusher 12 is installed below the combustion chamber 3. The pusher 12 moves in and out of the combustion chamber 3,
The melting raw material 16 filled in the combustion chamber 3 is pushed into the melting chamber 2 and supplied. If the pusher 12 frequently moves in and out of the combustion chamber 3, a large amount of the melting raw material 16 is supplied to the melting chamber 2, and if the pusher 12 is stopped, the melting raw material 16 is melted in the melting chamber 2. Corresponding to the amount of the melting raw material 16, it freely falls into the melting chamber 2 and is charged into the melting chamber 2. However, in this case, the amount of the melting raw material 16 supplied to the melting chamber 2 is not stable, and the supply of the raw material 16 may be stagnant in the combustion chamber 3 due to the hanging state.

A duct 21 connected to the exhaust gas treatment equipment 31 is provided above the combustion chamber 3, and the high-temperature exhaust gas generated in the melting chamber 2 passes through the combustion chamber 3 and the duct 21 to form the exhaust gas treatment equipment 31. Is discharged to. At that time, the combustion chamber 3
The melting raw material 16 charged in the combustion chamber 3 is preheated by the exhaust gas passing through.

The protruding portion 2a provided at a portion different from the side where the combustion chamber 3 is directly connected to the melting chamber 2 has its bottom portion pressed to the outlet side by a door 22 and stuffed with sand or mud inside. A tap hole 13 filled with the agent and a slag hole 14 whose side wall is filled with sand or mud agent and whose outlet side is pressed by a door 23 are provided. A burner 10 is attached to the upper lid 5 of the portion corresponding to the vertically upper side of the tap hole 13. Burner 10
Burns fossil fuels such as heavy oil, kerosene, pulverized coal, propane gas, and natural gas in the melting chamber 2 with air or oxygen or oxygen-enriched air. The melting chamber 2 is tilted toward the tap hole 13 side by a tilting device (not shown). In this way, the DC arc melting equipment 1 is constructed.

As the exhaust gas treatment equipment 31 connected to the downstream side of the duct 21, a secondary combustion chamber 32 is first connected to the duct 21 as shown in FIG. Air is supplied to the secondary combustion chamber 32 in order to burn the combustible components in the exhaust gas generated in the melting chamber 2 and raise the temperature of the exhaust gas. Also, in the secondary combustion chamber 32,
Auxiliary burner 3 that uses fuels such as heavy oil, kerosene, and LPG
3 is installed, and the auxiliary burner 33 can accelerate the combustion and temperature rise of the exhaust gas.

A cooling chamber 34 is installed downstream of the secondary combustion chamber 32. A water spray nozzle 35 is provided in the cooling chamber 34.
Is installed and the re-synthesis of harmful substances such as dioxins can be prevented by spraying cooling water to quench the exhaust gas.

A dilution air supply pipe 36 is connected to the downstream side of the cooling chamber 34 so that the dilution air and the exhaust gas can join. The diluting air may be either air sucked to collect dust in the building or air exclusively supplied as diluting air.

An adsorbent supply unit 37 and a blower 38 connected to the adsorbent supply unit 37 are installed downstream of the connecting portion of the dilution air supply pipe 36, and the adsorbent supply is performed via the blower 38. By supplying the adsorbent into the exhaust gas from the part 37, the harmful substances can be further reduced to a low level. In this case, slaked lime, activated carbon, coal ash or the like can be used as the adsorbent. A bag filter 39 is installed downstream of the adsorbent supply unit 37, and the exhaust gas passing through the bag filter 39 is installed downstream of the blower 40 via a blower 40 installed downstream of the bag filter 39. It is released from the chimney 41 into the atmosphere. The exhaust gas treatment facility 31 is configured in this way.

DC arc melting equipment 1 having such a configuration
When the waste vehicle press waste or the waste home appliance waste obtained from the used automobile or the used home electric appliance is recycled as the melting raw material 16 by using the exhaust gas treatment equipment 31, first, the melting chamber 2 is placed in a horizontal state and supplied. Bucket 1
The molten raw material 16 is charged into the combustion chamber 3 from 5. Combustion chamber 3
The melting raw material 16 charged therein is also charged in the melting chamber 2 and eventually fills the combustion chamber 3. In order to uniformly load the melting raw material 16 into the melting chamber 2, the upper lid 5 may be opened and the melting raw material 16 may be charged into the melting chamber 2 on the side opposite to the combustion chamber 3. Further, as described above, ordinary iron scrap, cold iron, and other cold iron sources such as direct reduced iron may be simultaneously charged into the combustion chamber 3 or the melting chamber 2 as the melting raw material 16.

Next, the upper electrode 7 is moved up and down while supplying a direct current between the bottom electrode 6 and the upper electrode 7, and the melted raw material 16 is placed between the bottom electrode 6 and the upper electrode 7 or charged.
An arc 19 is generated between the upper electrode 7 and the upper electrode 7. Then, the melting raw material 16 is melted by the generated arc heat to generate the molten metal 17. With the formation of the molten metal 17, quicklime,
A flux such as fluorite is charged into the melting chamber 2 to form the molten slag 18 on the molten metal 17 to prevent the molten metal 17 from being oxidized and to keep the molten metal 17 warm. When the amount of the molten slag 18 is too large, the molten slag 18 can be discharged from the outlet 14 even during melting.

Since the melting raw material 16 in the melting chamber 2 decreases with the generation of the molten metal 17, the operation of the pusher 12 is started from the time when the molten metal 17 is generated in the melting chamber 2. The pusher 12 may be operated so as to reciprocate within the combustion chamber 3 in about 10 seconds at intervals of several minutes, for example, once every 3 minutes. The melting raw material 16 to be filled in the combustion chamber 3 is forcedly pushed by the pusher 12 and supplied to the molten metal 17 side.

The melting raw material 16 in the combustion chamber 3 is the molten metal 1
Since it decreases with the generation of 7, the melting raw material 16 is charged from the supply bucket 15 into the combustion chamber 3 in order to make up for this decrease. The melting raw material 16 is charged into the combustion chamber 3 continuously or intermittently so that the state where the melting raw material 16 continuously exists in the combustion chamber 3 and the melting chamber 2 is maintained. However, in this case, it is necessary to adjust the supply amount of the melting raw material 16 to the combustion chamber 3 so that a space for burning the exhaust gas is always formed on the upper side of the combustion chamber 3. Specifically, the melt raw material 16 may be filled in one or two layers above the pusher 12.

From the time when the molten metal 17 is produced, the oxygen-containing gas is supplied into the melting chamber 2 through the oxygen-containing gas supply lance 8 to gasify and combust combustible substances contained in scraps of scraps of pressed cars and scraps of household appliances. Promote. The hydrocarbon-based combustible gas produced by gasification of the combustible material is combusted by the oxygen-containing gas. At this time, combustion heat is generated, and this combustion heat further promotes gasification of the combustible material contained in the undissolved raw material 16 and contributes to preheating the raw material 16. Therefore, the exhaust gas reaching above the melting raw material 16 in the combustion chamber 3 contains combustible gas, and the oxygen-containing gas is supplied through the oxygen-containing gas supply port 9 provided in the combustion chamber 3. Part of the combustible gas is burned, and the temperature of the exhaust gas at the outlet of the combustion chamber 3 and the duct 21 is generated as a volatile component by the heat of combustion, that is, the decomposition temperature of the tar-based composition in the exhaust gas, that is, 1000 Keeping the temperature above ℃ to generate tar
Prevent adhesion.

When the melted raw material 16 is melted and a predetermined amount of melt 17, for example, one heat, is accumulated in the melt chamber 2, the melt chamber 2 is tilted toward the melt outlet 13 and the melt outlet 1 is tilted.
The door 22 that has closed 3 is opened, and the molten metal 17 for one heat is discharged from the molten metal outlet 13 to a molten metal holding container (not shown).
At the time of tapping, the melt 17 may be heated by the burner 10 in order to prevent clogging of the tap hole 13 due to solidification of the tap metal 17. It should be noted that the predetermined amount of molten metal in the present invention means, for example, the amount of molten metal for one heat, or in the case of leaving the molten metal 17 in the melting chamber 2 after tapping, the amount of molten metal for one heat and the amount of molten metal in the melting chamber 2 It is an amount including the amount of residual molten metal, and is an amount of molten metal that is appropriately determined depending on the operating conditions.

When 80% or more of the copper member in the used automobile or the used household electric appliances is removed, or the melting raw material 1
When a large amount of ordinary iron scrap is used together as 6, the copper concentration in the molten metal 17 produced is 0.35 mass%.
Since it can be suppressed to the following, a steel product having a copper concentration standard of 0.35 mass% or less is produced from the molten metal 17. Therefore, when tapping, it is possible to adjust the chemical composition such as the carbon concentration of the melt 17 to the standard range of the target steel product before tapping, or tap it after refining in a ladle refining furnace etc. In that case, the hot water is adjusted to near the standard range, tapped, adjusted to the standard range for steel products in a ladle refining furnace, and then cast by a continuous casting machine or the like. In addition, when the copper concentration in the molten metal 17 exceeds 0.35 mass% and it cannot be directed to steel products as it is, hot metal or cold metal tapped from the blast furnace, or iron scrap is used. To dilute the copper concentration.

After the molten metal 17 is discharged, and the molten slag 18 is discharged as required, the melting chamber 2 is returned to the horizontal position, and the molten metal outlet 13 and the molten metal outlet 14 are filled with filling sand or mud material. , Next, start melting the heat.

At the time of tapping, the state in which the undissolved raw material 16 is continuously present in the combustion chamber 3 and the melting chamber 2 may be maintained, and the raw material 16 in the combustion chamber 3 and the melting chamber 2 may be maintained.
It is also possible to dissolve all of the ingredients and then release the hot water. When the melting raw material 16 is left in the combustion chamber 3 and the melting chamber 2, it is possible to preheat all the melting raw material 16 that is melted after the second heat, and it is possible to reduce the amount of power consumption. When all of the molten raw material 16 is melted for each tap, the temperature of the melt 17 at the tap can be adjusted arbitrarily, so troubles at tapping due to a decrease in the melt temperature (blocking of the tap 13 etc.) Can be prevented.

When the state where the undissolved raw material 16 is continuously present in the combustion chamber 3 and the melting chamber 2 at the time of tapping is maintained, the molten raw material 16 is buried in the molten metal 17 and coexists. Therefore, the molten metal temperature is close to the solidification temperature, and it is difficult to obtain a sufficient degree of superheat. Therefore, when the temperature of the molten metal at the time of tapping is raised, when a predetermined amount, for example, one heat of the molten metal 17 is accumulated in the melting chamber 2, the pusher 1
2 is stopped and the supply of the melting raw material 16 to the melting chamber 2 is reduced, and heating is performed by arc heating or the combined use of the arc heating and the burner 10, or the pusher 12
In the state where the melting chamber 2 is tilted to the tap 13 side after the stop of
It is preferable to perform heating by arc heating or a combination of arc heating and the burner 10. By doing so, the melting raw material 16 buried in the molten metal 17 is reduced, the contact area between the molten metal 17 and the melting raw material 16 is reduced, and the amount of heating energy contributing to the temperature rise of the molten metal 17 is increased. The molten metal 17 having a large degree of superheat can be obtained.

On the other hand, during this time, the exhaust gas containing the combustible gas discharged from the combustion chamber 3 is introduced into the secondary combustion chamber 32 through the duct 21, and in the secondary combustion chamber 32, the combustible gas in the exhaust gas is removed. After complete combustion, the exhaust gas temperature at the outlet of the secondary combustion chamber 32 is maintained at 850 ° C or higher. By maintaining the exhaust gas temperature at 850 ° C. or higher, dioxins can be decomposed. The auxiliary burner 33 may be used to secure the exhaust gas temperature at 850 ° C. or higher.

Exhaust gas heated to a predetermined temperature or higher in the secondary combustion chamber 32 is rapidly cooled to 250 ° C. or lower in the cooling chamber 34 to prevent re-synthesis of harmful substances such as dioxins. Furthermore,
The exhaust gas is mixed with the dilution air supplied from the dilution air supply pipe 36 and cooled to about 100 ° C. Furthermore,
If necessary, an adsorbent is supplied from the adsorbent supply unit 37,
Adsorbs and removes dioxin and other harmful substances remaining in exhaust gas. The exhaust gas is dust-removed by the bag filter 39, and then released from the chimney 41 into the atmosphere.

In this way, the scraps of scraps of pressed cars or scraps of household electric appliances are melted as the melting raw material 16 to melt used automobiles and used household appliances without shredding, that is, to generate shredder dust. Instead, used automobiles and used home appliances can be recycled as iron sources. Further, the molten raw material 16 is not directly charged into the molten metal 17 but is placed on the unmelted molten raw material 16 filled in the combustion chamber 3 and is preheated in the combustion chamber 3 and then supplied into the molten metal 17. Therefore, volatilization and combustion of the combustible material contained in the melting raw material 16 gradually progresses during preheating, and rapid combustion and smoke generation when immersed in the molten metal 17 can be prevented.

Further, by supplying the oxygen-containing gas to the upper portion of the combustion chamber 3, it is possible to raise the exhaust gas temperature to 1000 ° C. or higher at which the combustible gas in the exhaust gas is burned and the production of the tar-based composition can be suppressed. Therefore, it is possible to avoid troubles such as blockage due to tar adhesion in the duct 21 and the like.

Further, the exhaust gas is 850 ° C. in the secondary combustion chamber 32.
Since the temperature is maintained at the above temperature and then rapidly cooled to 250 ° C. or lower in the cooling chamber 34, the dioxins in the exhaust gas can be extremely reduced.

In the above description, the case of the DC type arc melting equipment has been explained, but the present invention can be applied to the AC type arc melting equipment in accordance with the above without any problem. Further, the positional relationship between the combustion chamber 3 and the tap hole 13 in the melting chamber 2 is not limited to a position facing the center of the melting chamber 2 by 180 degrees, but may be a position of 90 degrees.
In addition, when tapping the molten metal, several tons to several tens of tons of the molten metal 17 are melted into the melting chamber 2.
It may be left inside and the melting of the heat may be resumed next time.
By doing so, the initial dissolution is promoted and the dissolution efficiency is improved. Although the case of arc heating as the heating source has been described, gas burner heating, electric induction heating, plasma gas heating or the like can be used as a heating source other than arc heating.

[0051]

EXAMPLE An example of the DC arc melting equipment shown in FIG. 1 will be described below. The exhaust gas treatment equipment shown in FIG. 3 is connected to the arc melting equipment. The arc melting equipment has a melting chamber of 5.5 m in diameter and 3.5 m in height, and a combustion chamber has a maximum width of 3 m, length of 3 m, and height. At 7 m, the capacity of the melting chamber is 80
Tons. The scraps of scrap car used are 90% copper parts.
The used car removed above is pressed.

First, 15 tons of scraps of scrap car press were charged into the melting chamber and the combustion chamber, and melting by an arc was started. Then, as the molten metal was produced, the pusher was moved in and out of the combustion chamber at intervals of 3 minutes.

After this, when the scrap car press scraps in the combustion chamber descend as the scrap car press scraps in the melting chamber melt, the scrap car press scraps are charged into the combustion chamber by the supply bucket, and a space is always secured in the combustion chamber. As described above, melting was continued while the height of scrap car press waste in the combustion chamber was maintained within a certain height range. Then, when about 80 tons of molten metal is produced in the melting chamber, the operation of the pusher is stopped, the molten metal components are adjusted, and the temperature of the molten metal is raised. About 60 tons of molten metal was tapped into a ladle in a state where scrap car press scraps were continuously present in the combustion chamber.

After tapping, the scrap car press scraps are melted while maintaining the height of scrap car press scraps in the combustion chamber within a certain height range, and when the molten metal of about 80 tons is generated in the melting chamber, the pusher is operated. After adjusting the molten metal components and raising the temperature of the molten metal, about 20 tons of the molten metal is left in the melting chamber and about 60 tonnes of molten metal are left in the melting chamber and the combustion chamber in a state where scrap car press scraps are continuously present. Tons of tons were repeatedly discharged into a ladle.

The copper concentration of the molten metal thus obtained was all 0.35 mass% or less. The molten metal was cast by a continuous casting machine and then hot-rolled to produce a steel product having a copper concentration standard of 0.35 mass% or less.

During this period, industrial pure oxygen was supplied as an oxygen-containing gas to the melting chamber and the combustion chamber, and the exhaust gas temperature at the outlet of the combustion chamber was controlled to 1000 ° C. or higher. Then, the exhaust gas discharged from the combustion chamber is introduced into the secondary combustion chamber, where the combustible gas in the exhaust gas is burned to maintain the temperature of the exhaust gas at 850 ° C. or higher, and then the secondary combustion chamber is discharged. The exhaust gas was rapidly cooled to 250 ° C or lower in the cooling chamber. As a result, dioxins in the exhaust gas were reduced, and the concentration of dioxins in the exhaust gas could be made 0.1 ng-TEQ / Nm ³ or less. Further, no adhesion of the tar-based composition was observed in the duct or the secondary combustion chamber.

[0057]

EFFECTS OF THE INVENTION According to the present invention, it is possible to prevent generation and adhesion of a tar-based composition that is generated as a combustible gas from used automobiles and used home appliances, and prevent generation of harmful substances such as dioxins. Recycling a large amount of used automobiles or used home appliances without shredding as an iron source, in other words, without using any shredder treatment costs and shredder dust treatment costs, it is possible to dispose of used automobiles or used home appliances. It can be recycled as an iron source at a low cost, and brings industrial beneficial effects.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an embodiment of the present invention, which is a schematic vertical sectional view of an arc melting facility in which the present invention is carried out.

FIG. 2 is a schematic plan view of the arc melting equipment shown in FIG.

FIG. 3 is a schematic diagram of an exhaust gas treatment facility connected to an arc melting facility.

[Explanation of symbols]

1 DC arc melting equipment 2 Melting chamber 3 Combustion chamber 6 bottom electrode 7 Upper electrode 8 Oxygen-containing gas supply lance 9 Oxygen-containing gas supply port 12 pushers 13 Outlet 16 Melting raw material 17 Molten metal 18 Molten slag 19 arc 21 duct 31 Exhaust gas treatment equipment 32 Secondary combustion chamber 34 Cooling chamber 36 Dilution air supply pipe 37 Adsorbent supply unit 39 Bug filter 41 chimney

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F23G 5/50 F23G 7/00 A 4K014 7/00 B 4K045 F23J 1/00 B 4K056 F23J 1/00 F27B 3 / 08 4K063 F27B 3/08 3/18 3/18 3/22 3/22 F27D 13/00 D F27D 13/00 17/00 101G 17/00 101 B09B 3/00 303Z (72) Inventor Hideaki Mizukami Tokyo 1-1-2 Marunouchi, Chiyoda-ku Nihon Kokan Co., Ltd. (72) Inventor Katsuhiro Iwasaki 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Ryuji Yamaguchi Chiyoda-ku, Tokyo Marunouchi 1-Chome 1-2, Nihon Steel Pipe Co., Ltd. F term (reference) 3K061 NB02 NB30 3K062 AA16 AB03 AC13 BA02 BB02 CA01 DA01 DB05 3K065 AA16 AB03 AC 13 BA05 GA03 GA13 GA21 GA34 GA35 4D004 AA22 AA26 AC04 BA05 CA27 CA29 CB05 CB32 CC02 DA03 DA06 4K001 AA10 BA22 FA10 GA16 4K014 CB07 CB09 CC05 CD01 CD13 4K045 AA04 BA02 CA06 BA02 CA06 A02 CA06 BA02 DA02 BB02 DA02 BB02 DA02 BB02 DA02 BB02 GA02 GA09

Claims (6)

[Claims] 1. A melting facility having a melting chamber having a heating source and a shaft-type combustion chamber directly connected to the melting chamber is used, and is obtained from a used automobile or a used home appliance without shredding. When melting scrap car press scraps or waste home appliance scraps as a melting raw material, undissolved waste car press scraps or waste home appliance scraps remain in the melting chamber and the lower part of the combustion chamber, and exhaust gas burns in the upper part of the combustion chamber. In order to maintain a space for raising the temperature, the scrap car press scraps or waste home appliance scraps in the melting chamber are melted by the heating source while supplying scrap car press scraps or waste home appliance scraps to the combustion chamber. A method for recycling used automobiles or used home appliances, wherein the molten metal is discharged when a predetermined amount of molten metal is generated in the melting chamber. 2. An oxygen-containing gas is supplied into the melting chamber,
The method for recycling used automobiles or used home appliances according to claim 1, wherein gasification and combustion of combustible materials contained in scraps of scrapped automobile press or scraps of household electric appliances are promoted. 3. The oxygen-containing gas is supplied to the upper space of the combustion chamber to burn combustible gas generated from scraps of scrap of used cars or scraps of household electric appliances. Recycling method for used cars or used home appliances. 4. The supply amount of the oxygen-containing gas is adjusted to maintain the exhaust gas temperature at the combustion chamber outlet at 1000 ° C. or higher, and
A method of recycling used automobiles or used household appliances according to claim 2 or 3, wherein flammable gas is left in the exhaust gas at the outlet of the combustion chamber. 5. A combustible gas is burned in a secondary combustion chamber provided on the downstream side of the combustion chamber to maintain the exhaust gas temperature at 850 ° C. or higher, and then cooling provided on the downstream side of the secondary combustion chamber. The method for recycling used automobiles or used home appliances according to claim 4, wherein the exhaust gas is rapidly cooled to 250 ° C or lower in the room. 6. The method for recycling used automobiles or used home appliances according to claim 1, wherein the heating source is arc heating.