Vertical device for manufacturing recycled aluminum material

Abstract

[Problem] To provide a recycled aluminum material production device that, by using waste tires and a scrap material containing aluminum as the main resources, can efficiently produce, at a low cost, a recycled aluminum material containing few impurities. [Solution] A dry distillation gas is generated by using waste tires 08 in a first boiler 01 and a second boiler 02 serving as dry distillation gasification furnaces; in a first firing furnace (metal melting furnace) 04, the dry distillation gas is ignited, and the high temperature gas that is thereby produced is used to heat an inserted aluminum scrap material 11 containing iron and separate the iron from said scrap material; only the molten aluminum is caused to flow through a discharge port 12 and into a second firing furnace (metal melting furnace) 05; in the second firing furnace 05, the dry distillation gas that has been caused to flow therein from the second boiler 02 is ignited, and the high temperature gas that is thereby produced is used to heat an inserted pure aluminum scrap material 15 and molten aluminum that has flowed in from the first firing furnace 04; and the melted or re-heated aluminum is caused to flow outward to the outside of the second firing furnace 05, and a recycled aluminum material is produced.

Description

Vertical recycled aluminum manufacturing equipment

[0001] The present invention relates to a light metal melting facility that uses waste tires and aluminum-containing scrap materials as its main resources, and is capable of efficiently and low-costly producing recycled aluminum material with few impurities while minimizing aluminum loss during the recycling stage.

[0002] SDGs are an abbreviation for "Sustainable Development Goals," and are shared global goals unanimously adopted by member states at the United Nations Summit in September 2015. Target 5 of SDG 12 states, "By 2030, significantly reduce waste generation through prevention, reduction, recycling and reuse." Examples of recycling and reuse include melting metal products such as iron and aluminum to create new products from the recycled metals, and pelletizing plastic products to use in toys, as well as a method of generating energy from waste materials, as described in Patent Document 1, which states, "In a dry distillation gasification furnace, dry distillation gas is extracted from waste tires and combusted in a light metal melting furnace." There are a wide variety of ways to achieve this.

[0003] The invention described in the aforementioned Patent Document 1 is an apparatus that utilizes energy generated from waste materials (waste tires) and can melt metals using that energy to produce recycled metals. However, when melting scrap aluminum containing iron and extracting the aluminum that reaches its melting point first due to the difference in melting points between iron and aluminum to produce recycled aluminum, impurities contained in the recycled aluminum cannot be sufficiently removed in a single melting process. In order to increase the aluminum content to a level that allows it to be distributed as recycled material, the recycled aluminum must be heated in the same process to remove the impurities, which doubles the effort and cost.

[0004] Next, in order to raise the aluminum content of the iron-containing aluminum scrap material to a level that allows it to be distributed as recycled material, it is possible to provide a first and second melting process in a single metal recycling device. The invention in Patent Document 2 relates to a method for melting iron-containing material in which "the first melting process, the second melting process, and the tapping process constitute one melting process cycle, and this melting process is repeatedly carried out." However, when recycled aluminum material is produced using this method, since this invention is merely a process for tapping molten iron, if the iron-containing material is charged into a melting furnace in the second melting process, it is not possible to remove the impurities contained in the recycled aluminum material. Furthermore, this invention aims to shorten the cycle time, which is different from the aim of removing impurities.

[0005] The applicant also considered a method of placing two furnaces one above the other, as shown in Figure 1, melting aluminum scrap containing iron in the upper furnace, guiding the molten aluminum flowing out of the aluminum scrap through a hole connecting the two furnaces to the lower furnace, and reheating the molten aluminum in the lower furnace. However, because the molten aluminum heated in the lower furnace flows in little by little from the upper furnace, it tends to vaporize as it continues to heat, resulting in a loss of recyclable aluminum. While aluminum has a lower melting point than other metals and is easy to recycle, for example, when melting aluminum can scrap or aluminum engines to produce recyclable materials, placing these scraps in a furnace and heating them generally results in a loss of about 20% to 30%, which is a disadvantage. This method lacks business efficiency, and currently, there are more businesses exporting aluminum-containing scrap materials than businesses recycling aluminum domestically, making it difficult to expand the domestic recycling business.

[0006] JP 2006-343002 A Japanese Patent No. 7311771 A

[0007] Therefore, the objective of the present invention is to provide a recycled aluminum material production device that uses waste tires and scrap materials containing aluminum as the main resources, and can efficiently and low-costly produce recycled aluminum material with few impurities while minimizing the loss of aluminum during the recycling stage.

[0008] In order to solve the above problems, the recycled aluminum production apparatus according to the present invention comprises a first boiler (dry distillation gasification furnace) for generating dry distillation gas using waste tires, a first calcination furnace (metal melting furnace) connected to the first boiler through a flue, a second boiler for generating dry distillation gas using waste tires, a second calcination furnace (metal melting furnace) connected to the second boiler through a flue and stacked below the first calcination furnace, an exhaust flue for gas generated in the first calcination furnace, and an exhaust pipe to which the exhaust flue for gas generated in the second calcination furnace is connected and which leads to a chimney, and the first calcination furnace has an inlet for aluminum scrap material with iron and a flue on the bottom. The second firing furnace has an inlet for pure aluminum scrap and an aluminum inlet on its top surface, the aluminum outlet port of the first firing furnace and the aluminum inlet port of the second firing furnace are connected, the dry distillation gas generated from the first boiler is ignited in the first firing furnace, and the aluminum in the iron-containing aluminum scrap is melted by the heat, and the molten aluminum flows into the second firing furnace through the aluminum outlet port, and the dry distillation gas generated from the second boiler is ignited in the second firing furnace, and the pure aluminum scrap and the molten aluminum that has flowed in from the first firing furnace are simultaneously heated by the heat, thereby producing recycled aluminum. In addition to the above features, a water-cooled structure is provided on the outer periphery of the first boiler or the second boiler, and the water-cooled structure has a flow path that contacts the outer surface of the first boiler or the second boiler, and the flow path passes cooling water to cool the first boiler or the second boiler, and the cooling water after cooling is discharged as hot water, and the discharged hot water can be used as hot water for heating in greenhouse cultivation or underfloor heating in homes, or as hot water for drying wood, etc.Furthermore, in order to solve the above-mentioned problems, the method for producing recycled aluminum according to the present invention generates dry distillation gas using waste tires in a first boiler, and feeds iron-containing aluminum scrap into a first calcination furnace connected to the first boiler through a flue. In the first calcination furnace, the dry distillation gas flowing in from the first boiler is ignited, and the generated high-temperature gas of 1000°C to 1100°C heats the iron-containing aluminum scrap, separates it from the iron, and feeds only the molten aluminum into a second calcination furnace. In the second boiler, dry distillation gas is generated using waste tires. The dry distillation gas is then sent to a second calcination furnace connected through a flue, and in the second calcination furnace, the molten aluminum that has flowed in from the first calcination furnace and is stored in the second calcination furnace is heated by the dry distillation gas that has flowed in from the second boiler and the generated high-temperature gas of 650 to 800°C. Furthermore, pure aluminum scrap material is introduced into the stored molten aluminum and heated simultaneously, and the aluminum melted from the pure aluminum scrap material and the reheated molten aluminum that has flowed in from the first calcination furnace are discharged out of the second calcination furnace, producing recycled aluminum.

[0009] This system utilizes combustible gas generated from waste tires as a heat source for heating scrap materials in the first and second furnaces. The combustible gas is introduced into the furnaces, ignited, and generates high-temperature gas, which is then used to melt aluminum materials containing iron or aluminum with a high aluminum content. This configuration reduces fuel costs and eliminates the need for complex temperature control. Furthermore, maintaining the temperature in the first furnace at 1000°C to 1100°C prevents the emission of harmful and toxic substances such as dioxins, gases, and odors. Heating the aluminum scrap containing iron in the first furnace and then transferring the molten aluminum to the second furnace for reheating significantly reduces the impurities contained in the recycled aluminum produced from the molten aluminum in the second furnace. Pure aluminum scrap is added to the molten aluminum flowing from the first furnace to the second furnace, and the two are simultaneously heated in the second furnace. This prevents the loss of the pure aluminum scrap during melting and the vaporization of the molten aluminum, enabling the production of large amounts of recycled aluminum with fewer impurities. The structure of the present invention, which completes the entire process from adding waste tires to producing recycled aluminum in an integrated device, simplifies labor-intensive tasks and management, and also improves operational efficiency. The hot water discharged after cooling from each boiler can be used for heating purposes such as greenhouse cultivation and residential floor heating, or for drying wood, allowing for efficient use of the energy generated throughout the entire process from adding waste tires to producing recycled aluminum.

[0010] It is a side cross-sectional view of the recycled aluminum material producing device of the present invention. It is a diagram showing the flow of molten aluminum based on Figure 1. It is a flow chart showing the operation of the recycled aluminum material producing device of the present invention.

[0011] An embodiment of the recycled aluminum production apparatus of the present invention will be described below with reference to the accompanying drawings. As shown in the side cross-sectional view of Figure 1, the recycled aluminum production apparatus of the present invention includes a first boiler (pyrolysis gasification furnace) 01 for generating dry distillation gas using waste tires, a second boiler (pyrolysis gasification furnace) 02 stacked below the first boiler for also generating dry distillation gas using waste tires, a first calcination furnace (metal melting furnace) 04 connected to the first boiler 01 through a flue 03a for heating iron-containing aluminum scrap, a second calcination furnace (metal melting furnace) 05 stacked below the first calcination furnace 01 and connected to the second boiler 02 through a flue 03b for heating pure aluminum scrap, and an exhaust flue 06a through which gas and steam generated in the first calcination furnace 04 flows and an exhaust flue 06b through which gas and steam generated in the second calcination furnace 05 flows, connected to an exhaust pipe 07 leading to a chimney exposed to the outside of a building.

[0012] The first boiler 01 and the second boiler 02 are provided with dry distillation gasification furnaces each having a waste tire inlet 09 for storing waste tires 08 inside the first boiler 01 and the second boiler 02, and dry distill the waste tires 08 that have been introduced into the first boiler 01 and the second boiler 02 to generate dry distillation gas. The introduced waste tires 08 can be sufficiently gasified without the need for work such as crushing and compressing. Although not shown, the dry distillation gasification furnaces may be equipped with various functions, such as removing the ash from the waste tires 08 after dry distillation through an ash outlet door, or providing a water-cooling structure on the outer periphery to cool the furnaces of the first boiler 01 and the second boiler 02 after incineration.

[0013] The first firing furnace 04 is a metal melting furnace connected to the first boiler 01 via a flue 03a. Iron-containing aluminum scrap 11 is introduced into the first firing furnace 04 through an iron-containing aluminum scrap inlet 10, and the dry distillation gas obtained in the first boiler and introduced through the flue 03a is ignited. The temperature of the generated high-temperature gas is maintained at 1000°C to 1100°C to heat the iron-containing aluminum scrap 11. Because the melting point of iron in the iron-containing aluminum scrap 11 is 1536°C and that of aluminum is approximately 660°C, the aluminum melts first and flows out to the bottom. A molten aluminum outlet 12 is provided in the bottom of the first firing furnace 04, and only the molten aluminum flows out of the first firing furnace through the outlet 12, allowing the iron and aluminum to be separated. By inclining the bottom surface of the first firing furnace 04 and providing the outlet hole 12 at the lowest part, the molten aluminum flowing out from the iron-containing aluminum scrap material 11 can be efficiently collected in the outlet hole 12.

[0014] The second firing furnace 05 is a metal melting furnace connected to the second boiler 02 through a flue 03b. An inlet (not shown) connected to the outlet 12 at the bottom of the first firing furnace 04 is provided on the top of the second firing furnace 05. The second firing furnace 05 ignites the dry distillation gas introduced through the flue 03b and dry distilled in the second boiler 02, keeps the temperature of the generated high-temperature gas at 650°C to 800°C, and heats the molten aluminum 13 flowing in through the outlet 12 connecting the first firing furnace 04 and the second firing furnace 05 to produce pure aluminum slag. Pure aluminum scrap 15 is introduced through a scrap material inlet 14, and the molten aluminum 13 and the pure aluminum scrap 15 are heated simultaneously. A molten aluminum outlet 16 is provided at the bottom of the second firing furnace 05. Through the outlet 16, the molten aluminum, consisting of aluminum melted from the iron-containing aluminum scrap 11, which has been heated twice to remove impurities, and aluminum melted from the pure aluminum scrap 15 introduced into the second firing furnace 05, can be discharged out of the second firing furnace 05. In this case, it is desirable to introduce the pure aluminum scrap 15 when a certain amount of molten aluminum flowing from the outlet 12 has accumulated in the second firing furnace. This is because the pure aluminum scrap 15 is heated so that it dissolves in the molten aluminum, significantly reducing loss due to vaporization. This method allows for the production of more recycled aluminum than direct heating in a furnace. As with the first firing furnace 04, the bottom surface of the second firing furnace 05 is inclined and an outflow hole 16 is provided at the lowest part of the inclination, so that the molten aluminum can be efficiently discharged from the outflow hole 16.

[0015] The pure aluminum scrap material 15 to be fed into the second firing furnace 05 can be various, such as scrap aluminum window frames and sashes, or scrap frying pans and pots. However, since soft aluminum materials such as scrap aluminum beverage cans lose a large amount of weight even when compressed and fed into the furnace, it is desirable to use scrap aluminum such as frying pans and pots that are formed by stretching the aluminum, but this is not a limitation.

[0016] The exhaust pipe 07 is a cylindrical pipe connecting an exhaust flue 06a through which gases and steam generated in the first firing furnace flow out and an exhaust flue 06b through which gases and steam generated in the second firing furnace flow out, and the exhaust pipe 07 is connected to a chimney 17 exposed to the outside of the building, and discharges post-combustion gases, steam, etc. outside the building. The vertical recycled aluminum production device according to the present invention can prevent the emission of harmful / toxic gases and odors by increasing the temperature of the gas inside the firing furnace, but additional functions such as providing an exhaust gas analyzer between the exhaust flue 06a and 06b and the exhaust pipe 07 to further consider the environment may also be provided.

[0017] This system utilizes combustible gas generated from waste tires as a heat source for heating scrap materials in the first and second furnaces. The combustible gas is introduced into the furnaces, ignited, and used to melt the iron-containing aluminum and pure aluminum with a high aluminum content. This system reduces fuel costs and eliminates the need for complex temperature control. Furthermore, maintaining the temperature in the first furnace at 1000°C to 1100°C prevents the emission of harmful and toxic substances, gases, and odors, such as dioxins. Next, the system includes a process for heating the iron-containing aluminum scrap in the first furnace, then transferring the molten aluminum to the second furnace for reheating. This significantly reduces the impurities contained in the recycled aluminum produced from the molten aluminum in the second furnace. Then, pure aluminum scrap is added to the molten aluminum flowing from the first furnace to the second furnace, and the two are simultaneously heated in the second furnace. This prevents the loss of the pure aluminum scrap during melting and the vaporization of the molten aluminum, allowing for the production of a large amount of recycled aluminum with fewer impurities. Furthermore, the structure of the present invention, which completes the entire process from the introduction of waste tires to the production of recycled aluminum in an integrated device, simplifies labor-intensive tasks and management, and achieves operational efficiency. Additionally, the hot water discharged after cooling from each boiler can be used for heating purposes such as greenhouse cultivation and residential floor heating, or for drying wood, thereby efficiently utilizing the energy generated throughout the entire process from the introduction of waste tires to the production of recycled aluminum.

[0018] The operation of the vertical recycled aluminum production apparatus of the present invention will be described below with reference to the flow chart in Figure 3. In the dry distillation gas generation process, waste tires 08 are introduced into the first boiler (dry distillation gasification furnace) 01 and the second boiler (dry distillation gasification furnace) 02 shown in Figures 1 and 2 through waste tire inlets 09a and 09b on their sides. The first and second boilers are then ignited, and the waste tires 08 in the furnaces are dry distilled to generate dry distillation gas. In the high-temperature gas melting process, iron-containing aluminum scrap 11 is introduced into the first calcination furnace 04 through inlet 10. The dry distillation gas generated in the first boiler is then introduced into the first calcination furnace, where it is ignited. The temperature of the generated high-temperature gas is maintained at 1000°C to 1100°C, heating the iron-containing aluminum scrap 11 in the first calcination furnace. The aluminum melts first from the iron-containing aluminum scrap material 11, then flows down the bottom of the first baking furnace 04 and flows out of the molten aluminum outlet hole 12 provided on the bottom. In the medium- to high-temperature gas melting process, dry distillation gas generated in the second boiler is flowed into the second baking furnace 05, the dry distillation gas is ignited, the temperature of the generated high-temperature gas is maintained between 650°C and 800°C, and the molten aluminum 13 flowing from the outlet hole 12 of the first baking furnace is stored in the second baking furnace 05. In the molten aluminum mixing process, the temperature of the generated high-temperature gas is maintained between 650°C and 800°C, and pure aluminum scrap material 15 (scrap from aluminum frying pans and pots) is introduced from an inlet 14 into the molten aluminum 13 stored in the second baking furnace. Then, pure aluminum scrap material 15 and molten aluminum that has flowed in from the first firing furnace 04 through the outlet hole 12 are heated simultaneously. In the recycled aluminum production process, the molten aluminum heated in the second firing furnace 05 flows down the bottom of the second firing furnace 05 and into the molten aluminum outlet hole 15 located at the bottom of the second firing furnace. A recycled aluminum mold 18 is provided at the outlet of the outlet hole 15, and the molten aluminum is poured into the mold 18 to produce recycled aluminum. The iron-containing aluminum scrap material 11 heated in the first firing furnace 04 becomes iron material remaining in the furnace after the aluminum has flowed out, and in the first boiler and second boiler, the waste tires become ash or the like after dry distillation, so are removed from the respective devices.The first and second boilers, which are dry distillation gasification furnaces, are provided with a water-cooling structure such as water pipes on their outer peripheries to cool the furnaces, and the water used to cool the furnaces is discharged as hot water, which can be used for a variety of purposes, such as providing hot water to swimming pools, using it for greenhouse cultivation in vinyl greenhouses and for underfloor heating in homes, drying wood and wild plants (vegetables), using it in hot spring facilities, and as an energy source for power generation.

[0019] 01 First boiler (dry distillation gasification furnace) 02 Second boiler (dry distillation gasification furnace) 03 Flue 03a Flue connecting the first boiler and first kiln 03b Flue connecting the second boiler and second kiln 04 First kiln (metal melting furnace) 05 Second kiln (metal melting furnace) 06 Exhaust flue 06a Exhaust flue for gas and steam after combustion in the first kiln 06b Exhaust flue for gas and steam after combustion in the second kiln 07 Exhaust pipe 08 Waste tires 09 Waste tire inlet 09a Waste tire inlet for the first boiler 09b Waste tire inlet for the second boiler 10 Inlet for scrap aluminum with iron 11 Scrap aluminum with iron 12 Molten aluminum outlet hole for the first kiln 13 Molten aluminum melt flowing in from the first firing furnace 14: Inlet for pure aluminum scrap material 15: Pure aluminum scrap material 16: Outlet hole for molten aluminum in the second firing furnace 17: Chimney 18: Mold for recycled aluminum 19: Direction of movement of molten aluminum

Claims

1. A system comprising: a first boiler for generating dry distillation gas using waste tires; a first calcination furnace connected to the first boiler through a flue; a second boiler for generating dry distillation gas using waste tires; a second calcination furnace connected to the second boiler through a flue and stacked below the first calcination furnace; an exhaust flue for gas generated in the first calcination furnace and an exhaust pipe connecting the exhaust flue for gas generated in the second calcination furnace and leading to a chimney; the first calcination furnace has an inlet for iron-containing aluminum scrap material and an aluminum outlet hole on its bottom; the second calcination furnace has an inlet for pure aluminum scrap material and an aluminum inlet hole on its top; the aluminum outlet hole of the first calcination furnace and the aluminum inlet hole of the second calcination furnace are connected; and the dry distillation gas generated from the first boiler is ignited in the first calcination furnace, and the heat melts the aluminum in the iron-containing aluminum scrap material. The molten aluminum flows out through the aluminum outlet hole into a second firing furnace, and in the second firing furnace, the dry distillation gas generated from the second boiler is ignited, and the resulting heat simultaneously heats the pure aluminum scrap and the molten aluminum flowing in from the first firing furnace, thereby producing recycled aluminum.

2. The recycled aluminum generating device according to claim 1, characterized in that a water-cooling structure is provided on the outer periphery of the first boiler or the second boiler, the water-cooling structure has a flow path in contact with the outer surface of the first boiler or the second boiler, the flow path passes cooling water to cool the first boiler or the second boiler, the cooling water after cooling is discharged as hot water, and the discharged hot water can be used as hot water for heating greenhouse cultivation or floor heating in a house, or for drying wood, wild plants, or vegetables.

3. A first boiler generates dry distillation gas using waste tires, and aluminum scrap containing iron is fed into a first calciner connected to the first boiler through a flue. In the first calciner, the dry distillation gas flowing in from the first boiler is ignited, and the aluminum scrap containing iron is heated with the generated high-temperature gas of 1000°C to 1100°C, and the iron is separated, and only the molten aluminum is fed into a second calciner. In the second boiler, dry distillation gas is generated using waste tires, and the dry distillation gas is sent to the second calciner connected through a flue. In the second calciner, the molten aluminum flowing in from the first calciner and stored in the second calciner is heated with the generated high-temperature gas of 650°C to 800°C, and pure aluminum scrap is further fed into the stored molten aluminum and heated simultaneously. The recycled aluminum production method is characterized by producing recycled aluminum by melting the pure aluminum scrap material and discharging the reheated molten aluminum that flows from the first firing furnace to the second firing furnace.

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