JPH10147822A - Crucible type aluminum melting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce oxidizing loss and to efficiently and continuously melt by penetration-forming a molten metal tapping hole at the intermediate height of barrel part of a crucible, charging Al waste material from the upper part of the crucible, heating the crucible from the outer part and discharging molten Al to the outer part from the molten metal tapping hole. SOLUTION: The molten metal tapping hole 3 is penetration-formed near the intermediate height of the barrel part of the crucible 4. A partition member 16 is arranged at the position apart from the opening hole surface of the molten metal tapping hole 3 to shut off the molten metal tapping hole 2. The cut Al waste material 6 is charged into the crucible 4 from the upper opening hole, and the crucible 4 is heated with a burner from the outer periphery. the Al material 6 in the crucible 4 is melted from the lower part. Combustion gas is exhausted from the opening hole part 21 of a furnace cover 19 through a gap between the furnace wall 20 and the crucible 4. The molten metal stored in the crucible 4 is overflowed from the molten metal tapping hole 3 and discharged to the outer part of the crucible 4 and flowed out into a holding chamber 18 of the furnace body 1 and stored. This molten Al is discharged to out of the furnace from a molten metal tapping through 12 with the action of gravity. The molten Al 9 in the holding chamber 18 is heated with an auxiliary burner 11 to prevent the cooling of the molten Al 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum melting apparatus mainly for melting aluminum waste for recycling, and more particularly to a crucible capable of continuous melting using a crucible furnace as a prototype. The present invention relates to a furnace type aluminum melting apparatus.

[0002]

2. Description of the Related Art As is well known, recovered aluminum empty cans are appropriately cut into small pieces, melted, and recycled as recycled metal. Aluminum scraps from factories and other aluminum scraps, such as cutting chips and Dalai powder, are also melted to produce recycled metal.

[0003] Aluminum has a low melting point and can be easily melted in any type of furnace. Aluminum can be melted even in a conventional crucible furnace, but in a crucible furnace, the efficiency of the process is poor because the melting process and the operation of taking out the molten metal are alternately repeated. In order to continuously and efficiently dissolve aluminum waste materials, a reverberatory furnace is usually used.

[0004] However, the reverberatory furnace has a drawback that it has a large oxidation loss. The fine aluminum material is exposed to the combustion flame during melting and is oxidized, resulting in poor melting yield. In this regard, crucible furnaces in which the material to be melted is not exposed to the flame of the combustion chamber are superior.

In view of the above, various types of reverberatory furnace type aluminum melting devices designed to reduce oxidation loss have been proposed. For example, Japanese Unexamined Patent Application Publication No.
The apparatus disclosed in Japanese Patent No. 4-5095 has a configuration in which a molten metal is poured into an aluminum material using a pump. In the apparatus disclosed in Japanese Patent Application Laid-Open No. 1-132724, a vortex of molten metal is created by using a pump, and an aluminum material is charged toward the vortex. Similarly, JP-A-3-1203
No. 22 and Japanese Patent Application Laid-Open No. 156378/1990 use an electromagnetic stirrer to create a vortex of molten metal. By pouring the molten metal into the fine aluminum material or by pouring the fine aluminum material into the vortex of the molten metal, the time of air contact is reduced and the oxidation loss is reduced.

[0006]

As described above, in the conventional reverberatory furnace type aluminum melting apparatus in which measures to reduce oxidation loss are taken, initial equipment costs increase due to additional equipment such as a pump and an electromagnetic stirrer. There has been a problem that operation costs are increased due to maintenance of these complicated additional facilities. In order to promote the recycling of empty aluminum cans, it is strongly required that a melting apparatus can be installed and operated with as little cost as possible. In this respect, the conventional device was insufficient.

[0007] Further, in the conventional reverberatory furnace type aluminum melting apparatus, oxidation loss is reduced by instantaneously winding a fine aluminum material into the molten metal. Therefore, if moisture, oil, or the like is attached to the aluminum material, the attached substance may react instantaneously with the molten metal to cause a severe reaction such as a steam explosion. In order to prevent this danger, it is necessary to sufficiently remove the remaining deposits of the aluminum material before putting them into the furnace. That is, an aluminum material to be dissolved, such as a cut aluminum empty can, is subjected to heat treatment in advance to remove residual moisture, and to burn and remove organic substances and attached oils involved in surface printing. Conventionally, there has been a problem that expensive heat treatment equipment and dust collection equipment are required for this pretreatment.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object the need for equipment that is inexpensive and easy to maintain. Another object of the present invention is to provide a crucible furnace-type aluminum melting apparatus in which pretreatment of the furnace can be easily performed.

[0009]

The crucible furnace type aluminum melting apparatus according to the present invention basically has a crucible having a tap hole formed near an intermediate height of a body portion, which is directed upward substantially in the center of the furnace body. And the crucible is heated from the outer periphery by a burner, an aluminum material is put into the crucible from an upper opening, and the molten aluminum melted in the crucible is discharged from the tap hole to the outside of the crucible. I did it.

[0010] In the second invention, in addition to the above basic configuration, a partition member is provided in a portion of the crucible where the tap hole is formed, and the partition member is provided from the opening surface of the tap hole. The arrangement is such that the hole is appropriately separated and the hole is shielded, and the lower end of the partition member reaches the lower end position of the tap hole as appropriate. In this case, a configuration in which the partition member is attached to the upper end edge of the crucible so as to be hooked, and is suspended and installed inside the crucible, or a configuration in which the partition member is integrally joined to the wall of the crucible and provided. More preferably, both side portions of the partition member are configured to contact the inner peripheral surface of the body of the crucible.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a first embodiment of the present invention is shown in FIGS. A table 2 is installed at the center of a combustion chamber 7 surrounded by a refractory lining of a furnace body 1, and a graphite crucible 4 is placed on the table 2. The crucible 4 and the table 2 in the combustion chamber 7 are heated by the burner 5 installed in the hole in the side wall of the furnace body 1. Cleaning openings 10 are provided at two places on the side wall of the furnace body 1. In addition, a gantry 15 that covers the upper part of the furnace body 1 is installed, and an aluminum insertion device 17 and a stirring device 14 are mounted on the gantry 15.

A major feature of the structure of the present invention is that the tap hole 3 is formed through the crucible 4 near the middle height of the body. Another major feature is that a partition member 16 is formed in the portion of the crucible 4 where the tap hole 3 is formed.
The partition member 16 is appropriately separated from the opening surface of the tap hole 3 to shield the hole 3.
The lower end of 6 is appropriately below the lower end position of tap hole 3.

[0013] The graphite crucible 4 of the specific example is a cylindrical shape having a height of 1100 mm.
A rectangular tap hole 3 having a width of 100 mm is formed. The partition member 16 of this embodiment is attached so as to be hooked on the upper end edge of the crucible 4 and is suspended inside the crucible 4. The surface of the partition member 16 and the opening surface of the tap hole 3 are 30 m.
The interval is about m. Further, the lower end of the partition member 16 reaches about 80 mm below the lower end of the tap hole 3.
Further, as shown in FIG. 2, both side portions of the partition member 16 are bent toward the wall surface of the crucible 4, and both side portions are in contact with the inner peripheral surface of the body of the crucible 4.

An aluminum material 6 such as an aluminum can which has been appropriately cut into small pieces is put into the crucible 4 from the upper opening, and the crucible 4 is heated from the outer periphery by the burner 5. This heat causes the aluminum material 6 in the crucible 4 to melt from below. The combustion gas passes between the furnace wall 20 and the crucible 4 and is discharged from the opening 21 of the furnace lid 19. In order to promote the dissolution of the aluminum material 6, a stirrer 14 for stirring and mixing the aluminum material 6 and the molten metal is used.

Since there is a tap hole 3 substantially at the center of the body of the crucible 4, when a certain amount of molten metal accumulates inside the crucible 4, the molten metal spills out of the hole 3 and is discharged to the outside of the crucible 4. Then, it flows into the holding chamber 18 of the furnace main body 1 and accumulates. Inside the furnace body 1, there is a combustion chamber 7 to a holding chamber 18 and a hot water gutter 1
2 is formed, and the molten aluminum 9 accumulated in the holding chamber 18 is discharged out of the furnace from the tapping gutter 12 by the action of gravity. In order to prevent the cooling of the molten aluminum 9 in the holding chamber 18, an auxiliary burner 11 is installed in the furnace body 1, thereby heating the molten metal 9 from above.

As described above, the amount of the molten aluminum corresponding to the position of the tap hole 3 is accumulated in the crucible 4, so that the aluminum material 6 introduced from above comes into contact with the accumulated molten metal and is efficiently melted. The space above the surface of the molten aluminum inside the crucible 4 is pre-tropical, and the aluminum material 6 to be charged is accumulated in the pre-tropical zone and gradually melts into the molten metal from below.

If the position of the tap hole 3 in the crucible 4 is too low, the amount of the molten metal stored in the crucible 4 is reduced, the heat is taken by the aluminum material 6 to be charged, and the molten metal is solidified in a sherbet shape. Dissolution does not occur smoothly.
On the other hand, if the position where the tap hole 3 is formed in the crucible 4 is too high, the amount of accumulated molten metal increases and the position of the molten metal surface increases, and the pre-tropical space volume on the molten metal surface decreases accordingly. In that case, the aluminum material 6 that is thrown in and accumulated in the pre-tropical zone protrudes from the crucible 4, and the protruding aluminum material 6 is scattered by an air current generated from the burner 5. In consideration of such points, the forming position of the tap hole 3 is appropriately set.

Further, the partitioning member 16 is arranged on the inner surface side of the tap hole 3 to shield the hole 3 at a little distance from the tap hole 3. The tap hole 3 is closed by the aluminum material 6 put into the crucible 4. It is provided so as not to exist. On the surface of the molten metal, not only the unmelted aluminum material 6 and the sherbet-shaped aluminum material but also oxides are floating, and when these flow into the tap hole 3 with the molten metal flow and close the hole 3, the above-mentioned As described above, the surface level of the molten metal rises, and a smooth melting process is hindered. The partition member 16 prevents such a problem. Partition member 16
It suffices that the lower end of the crucible 4 has an appropriate distance from the inner surface of the crucible 4. The molten metal flows to the tap hole 3 through the space.

By sequentially charging the aluminum material 6 into the crucible 4 according to the melting rate in the crucible 4, the melting process can be continuously performed, unlike the ordinary batch process in a crucible furnace. The aluminum material 6 put into the crucible 4 does not immediately come into contact with the molten metal, but gradually falls downward while being heated in the upper space in the crucible 4 and is melted. That is, the upper space in the crucible 4 is a pre-tropical portion of the undissolved material portion, and the lower space is a melting zone in which the melting state proceeds. Even if deposits such as moisture and oil remain on the aluminum material 6, the deposits are removed during the passage through the pre-tropical zone, and there is little possibility that a violent reaction such as the steam explosion described above occurs, and the safety is high. Further, since the pre-tropical zone has a non-oxidizing atmosphere, the oxidation loss is extremely small.

[0020]

【The invention's effect】

(1) Dissolution treatment can be efficiently and continuously performed. (2) Only a suitable amount of molten aluminum is stored in the crucible, and a considerably large volume of pre-tropical zone is formed above the surface of the molten metal. Is effectively removed, so that the pre-treatment of the aluminum material can be simplified, a violent reaction such as steam explosion is unlikely to occur, and the melting operation can proceed safely. (3) Since the inside of the crucible is kept in a non-oxidizing atmosphere, oxidation loss is extremely small. (4) Since the crucible furnace is used as a prototype, the installation space is small, the equipment and maintenance costs are low, and the operating costs are low. (5) The deposit on the aluminum material can be used as fuel. (6) Since the melting apparatus has the above configuration, the melting of the aluminum ingot can be continuously performed.

[Brief description of the drawings]

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

FIG. 2 is a plan sectional view of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Furnace main body 2 Crucible stand 3 Tap hole 4 Crucible 5 Burner 6 Aluminum material 7 Combustion chamber 9 Aluminum melt 10 Cleaning opening 11 Auxiliary burner 12 Tapping gutter 14 Stirrer 15 Stand 16 Partition member 17 Aluminum insertion device 18 Holding room 19 Furnace lid 20 Furnace wall 21 opening

Claims (5)

[Claims] 1. A crucible having a tap hole formed in the vicinity of an intermediate height of a body portion is installed upward at substantially the center of a furnace body, and the crucible is heated from the outer periphery by a burner.
A crucible furnace type aluminum melting apparatus, wherein an aluminum material is put into the crucible through an upper opening, and the molten aluminum melted in the crucible is discharged from the tap hole to the outside of the crucible. 2. The crucible according to claim 1, wherein a partition member is provided in a portion of the crucible where the tap hole is formed, and the partition member appropriately separates from the opening surface of the tap hole to shield the hole. A crucible furnace type aluminum melting apparatus, wherein a lower end of the partition member appropriately reaches a lower position than a lower end position of the tap hole. 3. The crucible furnace type aluminum melting apparatus according to claim 2, wherein the partition member is attached so as to be hooked on an upper end edge of the crucible and is suspended inside the crucible. 4. The crucible furnace type aluminum melting apparatus according to claim 2, wherein the partition member is integrally joined to a wall of the crucible. 5. The crucible furnace type aluminum melting apparatus according to claim 2, wherein both side portions of the partition member are in contact with an inner peripheral surface of a body portion of the crucible.