JP2796274B2 - Melting furnace and melting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a melting furnace and a melting method used for regenerating light alloy chips generated as scrap.

[0002]

2. Description of the Related Art In recent years, attempts have been made to recycle and reuse light alloy chips generated as scrap in machining such as cutting from the viewpoint of resource saving.

[0003] A melting furnace for regenerating the light alloy chips includes a reflection furnace method in which the surface of the molten metal is directly heated by a heating burner, an electromagnetic induction furnace that melts by using electromagnetic induction,
There are various types of furnaces, such as a low-frequency induction furnace that melts using low frequency and a crucible furnace that heats from the bottom of the crucible with a heating burner.

[0004] Furnaces of the above-mentioned types have advantages and disadvantages in terms of fuel efficiency for melting, yield, initial cost of equipment or running cost, and so on. At present, such a melting furnace is used.

[0005] When regenerating light alloy chips generated by machining such as cutting, whether or not the regeneration is economically feasible depends on the fact that "fuel consumption" and "yield" representing the efficiency of melting itself are high. Of course, processes before and after the melting furnace (work)
That is, high overall efficiency is required throughout the entire regeneration process, such as the supply of the light alloy chips to the melting furnace or the discharge of the molten metal melted in the melting furnace.

[0006]

However, in the conventional melting furnace, as shown in FIG. 8, a ladle placed below a freely opening and closing tap hole 6 'provided on the lower side of the furnace. The molten metal is taken out into a casting (not shown) and transported to a casting site at a remote location where it is cast into a desired mold or into an ingot as an intermediate product. Further, as another mode, a treatment such as forming a hot water distribution path to the mold below the outlet of the melting furnace and pouring the molten metal directly into the mold has been performed.

[0007] In any of the above cases, only the treatment in the prescribed form can be performed. In such a case, the form after the regeneration treatment in the melting furnace is specified, and the flexibility is lost. Overall efficiency is reduced.

The present invention has been made in view of the above situation, and has a melting furnace capable of improving the yield of the melting furnace and the fuel efficiency, extending the life of the furnace, and increasing the efficiency of the entire melting equipment. And a dissolution method.

[0009]

According to a first aspect of the present invention, there is provided a melting furnace in which a light alloy chip is charged into a molten metal in the furnace and the molten metal surface is heated by an attached heating burner. In a light alloy chip melting furnace configured to melt an alloy chip, a heat-resistant stalk is disposed at the center in a plan view of the furnace from above the furnace so that the lower end is immersed in the molten metal, A light alloy inlet for charging a light alloy chip is provided on the other side, and a stirring blade for guiding the molten metal on the surface downward is provided at the upper end of the stirring blade.
Is provided below the stalk so as to be located below the lower end of the stalk , and the heating burner is disposed toward the surface of the molten metal outside the stalk.

[0010] The melting method according to the present invention according to claim 2 of the present invention is to put a light alloy chip into a molten metal in a furnace,
In a melting method in which a molten metal surface is melted by heating a molten metal surface with an attached heating burner, a heat-resistant stalk disposed in a central portion in a plan view from above the furnace so that a lower end is immersed in the molten metal. Insert the light alloy tip into the lower part of the stalk and the upper end from the lower end of the stalk.
The molten metal on the surface including the light alloy chips is guided downward by a stirring blade arranged so as to be located below, and the molten metal surface outside the stalk is heated and melted by the heating burner. .

[0011]

According to the light alloy chip melting furnace according to the first aspect of the present invention and the melting method according to the second aspect of the present invention, the lower end of the molten metal is immersed in the molten metal in the furnace. Since the light alloy chips are heated by the heating burner outside the stalk and the light alloy chips are injected into the stalk, the light alloy chips injected into the molten metal do not directly touch the flame of the heating burner. As a result, yield can be improved and high fuel efficiency can be obtained. Further, since the melting furnace itself is not heated, the life of the melting furnace itself can be extended.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially sectional plan view showing the structure of a melting furnace for a light alloy chip (in this case, aluminum) according to an embodiment of the present invention. FIG. 2 is a front sectional view of FIG. FIG. 2 is a side view of FIG. 1.

In FIGS. 1 to 3, A denotes a melting furnace, 1 denotes a melting furnace body having a base formed in a circular shape in plan view, 2 denotes a stalk (cylinder body) having an aluminum chip inlet 2b on the inner side, 3 Is a stirring blade, 4 is a drive shaft for rotating the stirring blade 3, 5
Is a heating burner, 6 is a ladle 10 with the melting furnace body tilted (Fig. 4
Reference numeral 7 is a beak-shaped molten metal discharge port having an open upper end and an upper part for discharging the molten metal. Reference numeral 7 denotes a molten metal discharge port having an open upper surface for pumping to the outside by a scoop-shaped pumping container.

As shown in FIG. 1, the molten metal outlet 6
The molten metal pumping port 7 is formed at a position facing the outer peripheral portion of the melting furnace main body 1, that is, facing the outer peripheral portion of the melting furnace main body 1 with the stalk 2 interposed therebetween.

The melting furnace A of this embodiment has a furnace inclining device having a well-known mechanism (not shown), for example, a hydraulic cylinder pivotally connected to the base side and the other to the melting furnace A side, and a hydraulic cylinder. As shown by a two-dot chain line L in FIG. 2, an inclined central axis ( (Not shown), the melting furnace body 1 is configured to be tiltable to the left by an angle θ.

In the melting furnace A according to this embodiment, the stalk 2 is concentrically disposed at the center of the base of the melting furnace main body 1, and the lower end thereof is formed as shown in FIG. It is arranged to be immersed inside. The stalk 2 is formed of a heat-resistant material, and is formed such that the flange portion 2a is engaged with a stalk mounting hole in the center of the melting furnace main body 1 and mounted.

At the center of the stalk 2, the stirring blade 3 is concentric as shown in FIG. 1, and as shown in FIG. The stirring blade 3 is disposed slightly below, and the upper end of the stirring blade 3 is located 50 to 150 mm below the surface S of the molten metal, preferably about 100 mm below. Then, the stirring blade 3 is rotated at a predetermined rotation speed (in this embodiment, approximately 100 rpm).
(350 rpm), the radius of the vortex formed by stirring the molten metal is set to be equal to the diameter of the Stoke 2, and the molten metal is rotated by the predetermined rotation of the stirring blade 3 so that the molten metal is stirred. It is configured such that a flow going from above to below is formed around 3. The rotation is performed by a prime mover (electric motor or the like) at the upper end (not shown) via the drive shaft 4. The drive shaft 4 is configured to be able to adjust the vertical position of the stirring blade 3 in the molten metal according to the liquid level of the molten metal by a lifting device for the stirring blade 3 (not shown).

As shown in FIG. 1 or FIG. 2, a stalk 2 is formed on the wall 1a of the melting furnace body 1 in height.
In the opening formed almost in the middle of the flame outlet 5a
The above-mentioned heating burner 5 is arranged so as to face the molten metal surface S side. Therefore, the heating burner 5 is used for the stoke 2
It will be located outside. In addition, this heating burner 5
In the present embodiment, the one having a performance of injecting a long flame such that the length of the flame goes around the outer peripheral area of the Stoke 2 is used. As shown in FIG. 1, an impurity outlet 8 for discharging impurities (slag) accumulated on the surface S of the molten metal to the outside is provided on the wall surface 1a of the melting furnace main body 1 as shown in FIG. Are provided in two places. Further, a discharge port 9 (see FIG. 2) used for discharging all the molten metal is formed in a lower portion of the melting furnace main body 1.

The melting furnace A has a plan view of FIG. 4, a plan view of FIG. 4 taken along the line II, a view taken along the line II-II of FIG. As shown in FIG. 7, a raw material supply hopper B, a scraper conveyor C, a crusher D, a centrifugal separator E, and a screw conveyor F are used to supply aluminum chips to the melting furnace A and process the molten metal from the melting furnace A. , A chamber G, a rotary kiln H, a scraper conveyor I, a supply chute M, a pumping robot J, and an ingot conveyor K are provided organically.

That is, the raw material supply hopper B is a device for charging a chip-shaped aluminum raw material (aluminum chips). As shown in FIG. 4 or 5, the upper part is formed in a funnel shape, and the funnel shape is formed. At the bottom is a screw conveyor B for discharging aluminum chips to the side of the scraper conveyor C.
₁ is located. In addition, the scraper conveyor C
Conveying, along a proximal end is connected to the distal end of the screw conveyor B ₁ of the raw material feed hopper B, the tip is connected to the supply portion D ₁ of the said crusher D, aluminum chips from the raw material supply hopper B to the crusher D It is configured to be. Then, the crusher D from the discharge portion D ₂ of lower crushed various sizes of aluminum chips supplied from the supply unit D ₁ of the upper comprises a known crushing means into a predetermined size of the chip , The supply port E of the centrifuge E
It is configured to discharge to _one . Also, the centrifuge E
Is discharged water, oil adhering to the peripheral portion of the aluminum chips crushed to the predetermined size are separated off from the chute E ₂ disposed below the supply port F ₁ of the screw conveyor F thereunder It is configured to be. Then, as shown in FIG. 4 or FIG.
Extends through the chamber G into the rotary kiln H. At the tip of the rotary kiln H,
Injection port is heated burner H ₁ in a state facing the proximal end side is disposed, and, in the rotary kiln H, inclined rotating drum H ₂ becomes lower at the tip side is laterally disposed, the aluminum The chips are the rotary drum H ₂ of this rotary kiln H
It is configured to pass through the inside of hot air from the base end to the tip. Also, at the lower end of the rotary kiln H,
A discharge port H ₃ for discharging the aluminum chips, are formed positioned above the supply port I ₁ of the scraper conveyor I.
Further, the scraper conveyor I shown in FIG.
As shown in FIG. 2, the supply port I ₁ located at the base end,
Comprising an outlet I ₂ to the raised front end from the base end, the hopper portion M of the discharge port I ₂ has the feed chute M
₁ It is configured to be located above. The supply chute conveyor M, when provided with the hopper M ₁ to the upper bets even tip Stoke 2 inward of the melting furnace A from the hopper M ₁ is provided with a leading chute M _2.

Further, as shown in FIG. 4, a scoop-shaped pumping vessel J provided at the tip is located near the melting furnace A.
A work arm J ₁ (see a dashed line) for moving the molten metal ₂ from the position of the molten metal pumping port 7 of the melting furnace A to the base end position of the ingot conveyor K is provided. , A pumping robot J is provided. And in the ingot conveyor K,
Along with the ingot mold k on the conveying surface,
The tact operation is performed in synchronization with the pouring operation of the pumping robot J.

In the present embodiment, a ladle disposing portion (a portion where the ladle 10 is disposed) for disposing the ladle 10 is formed below the molten metal discharge port 6 of the melting furnace A in the present embodiment. ing.

Thus, the melting furnace A and the melting equipment according to the present embodiment configured as described above operate as follows in the melting processing of the aluminum chips.

That is, as shown in FIGS. 4 to 7, when an aluminum chip is put into the supply hopper B, the aluminum chip is conveyed from the supply hopper B to the crusher D by a scraper conveyor C and has a desired size. Then, oil or moisture attached to the aluminum chip is removed by a centrifugal separator E below the crusher D. Then, the aluminum chips oil or water or the like is removed as is discharged from the chute E ₂ centrifuges E to screw conveyor F side, in a rotary kiln H through the chamber G by the screw conveyor F The aluminum chips are carried and dried and preheated in the rotary kiln H. Then, the aluminum chips subjected to the processing necessary for melting in this way are conveyed to the supply chute M by the scraper conveyor I, and supplied to the inside of the stalk 2 of the melting furnace A by the supply chute M.

In the lower part of the stalk 2 of the melting furnace A, as shown by the arrow R in FIG. The removed aluminum chips are quickly drawn into the molten metal without floating on the surface. Then, the molten metal containing the aluminum chips is carried along the convection (see the arrow R in FIG. 2) around the outside of the stalk 2 of the melting furnace main body 1,
Here, the desired melting is performed by being heated by the heating burner 5. In this melting furnace A,
The aluminum chip is supplied into the stalk 2 and does not directly come into contact with the flame of the heating burner 5, so that the aluminum chip does not oxidize, so that a high yield and high fuel efficiency can be obtained.

The aluminum chip melted in a predetermined state as described above is used for manufacturing the ingot as shown in FIG.
Are pumped out by a robot J, and are sequentially poured into a mold k of an ingot conveyor K which is operated in a takt operation in synchronism with the pouring operation of the pumping robot J, and a desired aluminum ingot is completed.

When taking out the molten metal into the ladle 10, the furnace body tilting device (not shown) is operated to tilt the melting furnace A within the range of the angle θ as shown by the two-dot chain line in FIG. It can be taken out from the outlet 6 to the ladle 10 below it.

As described above, according to the melting furnace of the present embodiment, when the ingot is taken out to the mold k and the ladle 10 for manufacturing the ingot,
By operating the pumping robot J or the furnace tilting device of the melting furnace, the molten metal can be selectively extracted from the molten metal pumping port 7 or the molten metal discharge port 6.
This results in a very flexible melting furnace. Furthermore, since the melting furnace melts the aluminum chips put into the stalk as described above, extremely efficient heat transfer and convection of the molten metal for equalizing the temperature of the molten metal in each part are performed in the melting furnace. As a result, the dissolving operation of the aluminum chips can be performed very smoothly and with little heat energy.

Further, according to the melting equipment according to the present embodiment, the aluminum chips are simply put into the supply hopper, and thereafter the aluminum chips are converted into aluminum chips suitable for the melting process without manual operation, and are fixed in the melting furnace. Since it can be supplied in a quantity, it can be taken out as a molten metal for an aluminum ingot or in a ladle in a molten state. As a result, the present melting equipment can process a large amount of aluminum chips per unit time without requiring much manpower, and requires less heat energy and obtains a high yield. Equipment.

By the way, in the above embodiment, when the melting furnace is close to the mold, a hot water distribution passage communicating with the mold may be formed instead of the ladle disposing portion.

Although the present embodiment has been described with reference to the case of exclusively using aluminum chips, it goes without saying that the present invention can be similarly applied to other light alloy chips.

[0033]

According to the melting furnace and the melting method of the aluminum chip according to the first and second aspects of the present invention, the light alloy chip is melted as described above. Thus, the light alloy chip can be extremely efficiently melted.

[0034] Therefore, scrap light alloy chips that could not be used conventionally due to profitability can be reclaimed, which contributes to resource saving.

Further, since the melting furnace is not directly heated by the heating burner and the temperature of the molten metal in the furnace can be made uniform, the life of the melting furnace is extended as compared with the conventional furnace. be able to.

[Brief description of the drawings]

FIG. 1 is a partially sectional plan view showing a configuration of a melting furnace for a light alloy chip according to an embodiment of the present invention.

FIG. 2 is a front sectional view showing a configuration of a melting furnace for a light alloy chip of FIG. 1;

FIG. 3 is a side view showing a configuration of a light alloy chip melting furnace of FIG. 1;

FIG. 4 is a plan view showing the melting furnace of FIG. 1 and its peripheral devices.

FIG. 5 is a view taken along the line II of FIG. 4;

6 is a view taken in the direction of arrows II-II in FIG. 4;

7 is a view taken in the direction of arrows III-III in FIG. 4;

FIG. 8 is a front sectional view showing the configuration of a conventional reverberatory furnace-type melting furnace.

[Description of symbols] A ... melting furnace 6 ... melt outlet 7 ... molten metal pumping port J ... pumping robot J ₁ ... actuation arm

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F27B 3/00-3/28 C22B 9/16 C22B 21/00-21/06

Claims (2)

(57) [Claims] 1. A light alloy chip melting furnace configured to throw light alloy chips into a melt in a furnace and heat the surface of the melt with an attached heating burner to melt the thrown light alloy chips. A heat-resistant stalk is disposed at the center of the furnace in plan view from above the furnace so that the lower end is immersed in the molten metal, and a light alloy insertion port for charging a light alloy chip is provided inside the stalk, and The stirring blade for guiding the molten metal on the surface downward, the upper end of the stirring blade is lower than the lower end of the stalk.
Characterized in that the heating burner is arranged toward the surface of the molten metal outside the stalk so as to be located at a position below the stalk. 2. A melting method in which a light alloy chip is poured into a molten metal in a furnace, and a surface of the molten metal is heated by an attached heating burner to melt the light alloy chip. A light alloy chip is inserted into the heat-resistant stalk disposed at the center in a plan view from above the furnace, and the stalk is inserted into a lower part of the stalk.
Agitating blades arranged so that the upper end is located lower than the lower end guides the molten metal on the surface including the light alloy chips downward, and heats and melts the molten metal surface outside the stalk with the heating burner. Characteristic light alloy chip melting method.