JP2001108376A - Bottom casting type float melting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable execution of casting in a smaller casting radius than usual, to enable control of the amount of casting with high accuracy in a wide range, while keeping molten metal at high purity, and to enable stop of casting and execution of re-casting. SOLUTION: The frequency of a current supplied to an induction coil 5 for casting is made a prescribed one in the range of 100 to 500 kHz.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of melting a material to be melted in a metal crucible in a floating state, tapping the molten metal from an outlet of the metal crucible and casting the molten metal in a mold, or manufacturing an amorphous bulk or a foil strip, or The present invention relates to a bottom tapping type levitation melting apparatus for performing atomizing.

[0002]

2. Description of the Related Art Conventionally, a levitation and melting apparatus of this type uses a lower induction coil, for example, of an upper and lower induction coil to which current is supplied from upper and lower separate power sources when the molten metal is melted by the levitation and melting apparatus. Japanese Patent Application Laid-Open No. Hei 7-245182 discloses a flotation and melting apparatus in which the current is reduced so that the molten metal is discharged from an outlet at the bottom of the metal crucible. Japanese Patent Laid-Open Publication No. Hei 10-38467 discloses a flotation / melting apparatus having a control device for controlling the temperature and the method of tapping, and further comprises mounting a crucible made of a copper segment in a vacuum or inert gas atmosphere and having an opening at the bottom. Dissolving the titanium and bringing it into contact with the crucible to form a titanium skull so that the molten titanium does not come into contact with anyone other than the skull; Atomizing, in which the molten titanium flows down from the bottom opening of the crucible, which reduces the current of the induction coil wound around the outer periphery of the crucible, and blasts the molten metal into titanium particles by blowing an inert gas at almost right angles to the molten metal flow 7-9
No. 1571.

[0003]

Unlike a conventional refractory apparatus using a refractory, a levitation melting apparatus does not mix from a crucible material, so that a pure metal or alloy can be melted with high purity. The molten metal obtained by flotation melts flows out of the outlet at the bottom of the crucible.However, in the conventional bottom-floating flotation apparatus, the amount of molten metal is reduced by the static pressure of the molten metal, the cross-sectional area of the hole at the outlet, and the flow of the molten metal. The electromagnetic drawing force to be applied and the flotation / melting device excluding the power supply device are housed in a vacuum tank, and a vacuum-sealed partition is provided at the lower end of the outlet to divide the vacuum tank into two upper and lower tanks. In some cases, a control for increasing the pressure in the lower chamber and narrowing the diameter of the tapping water flow when the tapping is performed from the outlet port so that the vacuum chamber communicates only with the outlet port of the metal crucible may be added.

The magnetic drawing force differs depending on the electric resistivity of the molten metal. When the tapping diameter is the same, the drawing force is inversely proportional to the square root of the electric resistivity of the molten metal. Since the drawing force acting on the molten metal decreases as the drawing flow is reduced to a cross-sectional area smaller than the cross-sectional area of the outlet by the drawing force, a pressure difference under vacuum is added to the conventional magnetic drawing force. In the method, the tapping diameter that can be controlled with high precision was limited to 5 mm.

[0005] In casting and atomizing, it is important to keep the flow rate of the molten metal constant and to cast the molten metal straight into the gate, but the amount of molten metal depends on the static pressure of the molten metal. , There was a problem that the amount of hot water was not constant. This may cause a deviation in the solidification rate in casting, or a so-called running out of molten metal in which the molten metal does not drop straight, leading to casting defects. Also, in atomization, it is necessary to control the gas flow rate for atomization in accordance with the amount of hot water in order to keep the powder size constant.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to enable tapping with a smaller tapping diameter than before, and to maintain the molten metal at a high purity while discharging the molten metal at a high purity. An object of the present invention is to provide a bottom-floating-type flotation / dissolution apparatus capable of controlling the amount of hot water with high precision over a wide range and capable of stopping or restarting hot water supply.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 has a plurality of radial slits in a radial direction and an outlet for discharging molten metal at a bottom portion, and is attached to the outlet. In a levitation and melting apparatus that performs levitation melting and tapping from an outlet with a metal crucible provided with a tapping induction coil on the outer peripheral side of the nozzle, the frequency of a current supplied to the tapping induction coil is 100 kHz to 500 KHz.
The frequency is a predetermined frequency in a range of KHz.

According to a second aspect of the present invention, there is provided a bottom tapping type flotation and melting apparatus according to the first aspect, wherein a desired tapping amount,
Alternatively, a nozzle having a hole diameter or a length different from that of a nozzle corresponding to a tapping diameter or a required length for maintaining the tapping diameter is used.

According to a third aspect of the present invention, in the bottom tapping type flotation melting apparatus according to the first or second aspect, the nozzle is water-cooled.

According to a fourth aspect of the present invention, in the bottom tapping type flotation melting apparatus according to any one of the first to third aspects, the nozzle has one or more vertical slits. I do.

According to the first to fourth aspects of the present invention,
The tapping diameter can be restricted by the nozzle hole diameter, and a desired tapping diameter can be obtained by replacing the nozzle with a nozzle having a different hole diameter.
Further, by making the nozzle water-cooled, it becomes possible to prevent the molten metal from reacting with the nozzle and taking in impurities in the molten metal. Further, when a water-cooled nozzle is used, the molten metal at the bottom of the crucible and the upper part of the nozzle is in soft contact with the bottom of the crucible and the upper part of the nozzle and becomes a semi-molten state. As a result, the magnetic flux entering from the slit increases, and the metal in the semi-molten state can be melted.

Further, by selecting the frequency of the induction coil on the outer peripheral side of the nozzle to be a predetermined frequency in the range of 100 KHz to 500 KHz, it is possible to obtain a frequency of 100 KHz from Table 1.
In, up to 5.6 mm tapping diameter and up to 2.5 mm tapping diameter at 500 KHz, it is possible to efficiently input heat into the tapping water stream and use the drawing force, and control the tapping diameter over a wide range with high accuracy. Becomes possible.

It should be noted that as a range in which the heat input and the drawing force can be efficiently performed, the tapping diameter / penetration depth is set to> 3.5. This makes it possible to prevent the heat from entering the hot water stream and being solidified in the nozzle by induction heating from the induction coil on the outer peripheral side of the nozzle even if the heat is removed by the nozzle while passing through the water-cooled nozzle.

[0014]

[Table 1] Operating frequency, penetration depth, and controllable tapping diameter when the molten metal resistivity is 100 μΩ · cm Further, the invention described in claim 5 provides the invention according to claims 1 to 4.
In the bottom tapping type flotation melting apparatus according to any of the above,
Providing a tap with a drive device that opens and closes the outlet from the top or bottom, and starts tapping by vertical movement of the tap,
Alternatively, it is characterized in that stop and restart hot water are performed.

With the above configuration, it is possible to prevent a lump of molten metal from falling out of the outlet to such an extent that buoyancy is not applied immediately after the start of melting. Further, it is possible to stop tapping by closing the tap, and to start tapping again by opening the tap again.

According to a sixth aspect of the present invention, there is provided the bottom tapping type flotation melting apparatus according to any one of the first to fourth aspects, wherein a material plug is formed in the nozzle hole even if the material is made of the same material as the melting material. It is characterized by being provided so as to cover, and at the time of tapping, the tapping coil is melted by the tapping induction coil on the outer peripheral side of the nozzle to start tapping.

[0017] With the above structure, even if it is made of a material of the same quality as the dissolving material, the buoyancy force is not added immediately after the start of melting without using a tap which is immersed in the molten metal by covering the nozzle hole with a plug. It is possible to prevent the molten metal lump from falling out of the outlet.

According to a seventh aspect of the present invention, there is provided the bottom tapping type flotation melting apparatus according to any one of the first to sixth aspects, wherein a molding chamber for treating the molten metal under vacuum is provided below the nozzle. , A metal crucible, an induction coil for floating and melting the metal crucible, a nozzle attached to the outlet, a vacuum melting chamber containing a induction coil for tapping and having a lower part partitioned by a partition wall, and melting the molten metal in the metal crucible. The partition is provided by providing a molding chamber for processing under vacuum, and having a passage hole in contact with a lower end portion of the nozzle and allowing the flow of the molten metal to flow therethrough, so that air can flow between the upper and lower chambers only through the passage hole. And a partition jacket through which a vacuum melting chamber,
And a separate vacuum evacuation system is provided in each of the molding chambers.

The invention according to claim 8 is the bottom tapping type levitation melting apparatus according to claim 7, wherein the power supplied to the induction coil for levitation melting is controlled to control the tapping diameter and tapping.
To control the power or frequency applied to the tapping induction coil to control the generation of a pressure difference between the vacuum pressure in the vacuum melting chamber and the forming chamber to add a drawing force to the tapping flow when controlling the stop of tapping. And a control for adding a throttling force to the tap water flow.

According to the seventh and eighth aspects of the present invention, 100 KH is explained in the first to fourth aspects.
In z, the tapping diameter is up to 5.6 mm, and at 500 KHz, the tapping diameter is up to 2.5 mm, which allows efficient heat input to the tapping flow and effective use of the drawing force, and controls the tapping diameter in a wide range with high accuracy. As a result, even if heat is extracted from the nozzle while passing through the water-cooled nozzle, heat is input by induction heating from the hot water induction coil on the outer peripheral side of the nozzle, and the hot water flow solidifies in the nozzle. In addition to the above, the pressure P1 in the vacuum melting chamber is formed at the start of tapping by simultaneously using the pressure control of the upper and lower vacuum tanks by the respective vacuum evacuation systems of the vacuum melting chamber and the forming chamber. Chamber pressure P2
The pressure of each vacuum evacuation system is controlled to be higher so that the molten metal whose upper pressure is higher than the lower pressure is pushed out from the outlet, and the power of the levitation induction coil is Hot water is controlled so that the pressure control is added to the electric power control, so that it is possible to shorten a rising time until reaching a fixed amount of hot water.

In addition, at the time of fixed-quantity tapping following the start of tapping, the upper and lower vacuum evacuation systems are controlled so that the pressure P2 in the molding chamber is higher than the pressure P1 in the vacuum melting chamber, so that the pressure below the melt is increased. By controlling the flow of the molten metal from the branch outlet and by restricting the flow of the molten metal by controlling the power of the induction coil on the outer peripheral side of the nozzle, it is possible to expand the control range of the fixed amount of molten metal per unit time.

Further, in the last stage of tapping, the upper and lower vacuum evacuation systems are pressure-controlled so that the pressure P1 in the vacuum melting chamber is higher than the pressure P2 in the forming chamber, so that the upper pressure of the molten metal is higher than the lower pressure. The molten metal is extruded from the outlet, and the power of the levitation induction coil is controlled so that the molten metal flows out.The pressure control is added to the power control, and the fall time until the end of the molten metal is shortened. It becomes possible to do.

As described above, when the molten metal is discharged, the rise and fall time can be reduced by using the power control of the induction coil for levitation and melting and the induction coil on the outer peripheral side of the nozzle in combination with the pressure control of the upper and lower vacuum tanks. At the same time, it is possible to change the amount of hot water per unit time at the time of constant temperature hot water supply over a wide range.

According to a ninth aspect of the present invention, in the bottom tapping type levitation melting apparatus according to the seventh or eighth aspect, gas is sprayed toward a tapping flow into the forming chamber to generate powder metal. It is characterized by providing an atomizer. With the above configuration, the tapping diameter can be kept substantially constant over a wide range from the start to the end of tapping, and highly accurate atomizing can be performed.

The invention according to claim 10 is the same as the invention according to claim 7.
Alternatively, in the bottom tapping type levitation melting apparatus according to claim 8, a rapid cooling and solidifying mechanism for producing an amorphous bulk or a foil strip is provided in the molding chamber. With the above configuration, the tapping diameter can be kept substantially constant over a wide range from the start to the end of tapping, and it is possible to manufacture a non-crystallized bulk or foil strip with high precision.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
8 shows a configuration diagram of a main part of the embodiment of the invention described in FIG.
In FIG. 1, reference numeral 1 denotes a water-cooled metal crucible having a plurality of radial slits 1a in a radial direction and an outlet 1b for discharging a molten metal 2 at a bottom portion. An upper induction coil 4 mainly for giving melting energy, a lower induction coil 4 for mainly giving a levitation force to the molten metal 5,
Is attached to the outlet 1b, is wound around the outer periphery of the nozzle 6 for restricting the diameter of the tapping stream, and supplies a tapping induction coil for applying heating energy and drawing force to the tapping stream. Reference numeral 7 denotes a metal crucible 1 and a vertical induction coil 3. , 4, a vacuum melting chamber for housing a flotation furnace in which a tapping induction coil 5 and a nozzle 6 are integrated, and 8 is a chamber formed by partitioning the lower part of the vacuum melting chamber with a partition wall and having a passage hole through which the tapping water flows. The lower end of the nozzle 6 is brought into contact with the upper end of the partition jacket 11 having the metal crucible 1 so that the inside of the metal crucible 1 communicates with the lower portion only through the nozzle hole and the passage hole of the nozzle 6, and the molten metal flowing out through the nozzle 6 is treated. A molding chamber 9 for evacuating the inside of the vacuum melting chamber 7; a molding chamber-side exhaust device for evacuating the inside of the molding chamber 8; a power supply 12 for supplying a high-frequency current to the upper induction coil 3; 13 is lower guidance Yl 4 Power supplying a high frequency current to, 14 from 100KHz to give force and aperture heated energy to hot water flow through the induction coil 5 for tapping 500K
A power supply for supplying a predetermined high-frequency current between 1 Hz and 15 denotes a mold for casting the molten metal 2 discharged through the nozzle 6. In FIG. 1, a vacuum melting chamber 7 and a molding chamber 8 thereunder are formed by a metal crucible 1 mounted in the vacuum melting chamber 7.
The upper and lower sides of a partition jacket 11 closely attached to a lower end of a nozzle 6 attached to an outflow port 1b are separated from each other by a side surface of a partition jacket 11, and are provided in a vacuum melting chamber 7 and a molding chamber 8, respectively. Exhaust device 9, forming chamber side exhaust device 1
After the pressure is reduced to a predetermined degree of vacuum by 0, the melting operation is started. An initial material to be melted is charged in the metal crucible 1 in advance, and when current is supplied to the upper and lower induction coils 3 and 4 from AC power supplies 12 and 13 installed outside the vacuum melting chamber 7, The magnetic flux generated by the current flowing through the upper and lower induction coils 3 and 4 penetrates into the metal crucible 1 through the slit 1a and interlinks with the material to be melted to induce an eddy current, and also induces an eddy current in the metal crucible 1. I do. The material to be melted is heated by the eddy current in the material to be melted, and generates an electromagnetic force between the material and the eddy current induced in the metal crucible 1. Since the two eddy currents are opposite to each other on the opposing surfaces, the electromagnetic force becomes a repulsive force. Since the metal crucible 1 is fixed, a levitation force is given to the material to be melted, and the material to be melted melts and floats. It becomes molten metal 2. The molten metal 2 melted in the metal crucible 1 does not come into contact with other objects at the time of melting, so that there is very little contamination with foreign matter, it is possible to melt even a material having a high melting point, and heat conduction loss is small. Therefore, it is used for dissolving materials that require a high melting point and high purity, such as titanium and silicon.

Further, since the metal crucible 1 is melted in a vacuum or an inert gas atmosphere, contamination from the atmosphere can be prevented and active metal can be melted.

The molten metal 2 melted as described above is controlled by the power of the upper and lower induction coils 3 and 4 and is supplied to the electromagnetic flow of the induction coil 5 for tapping into a tapping flow having a diameter regulated by the nozzle 6 attached to the outlet 1b. The squeezing force is applied to the squeeze so that the smelt is spouted at a desired spout diameter and cast into a mold 15 in the forming chamber 8. In addition, in order to perform a fixed amount of hot water from the beginning to the end of hot water,
The vertical induction coils 3 and 4 and the tapping induction coil 5
In addition to the power control described above, pressure control of the upper and lower vacuum tanks by the melting chamber side exhaust device 9 and the molding chamber side exhaust device 10 is used in combination. That is, at the start of tapping, the pressure P1 in the vacuum melting chamber 7
Is controlled so that the pressure becomes higher than the pressure P2 of the molding chamber 8, and the power of the upper and lower induction coils 3 and 4 and the power of the induction coil 5 for tapping are controlled while controlling the pressure of the melting chamber side exhaust device 9 and the molding chamber side exhaust device 10. Then, the hot water is discharged from the nozzle 6 attached to the outlet 1b at the bottom of the metal crucible 1 so as to shorten the rise time until reaching the fixed amount of hot water. In addition, at the time of fixed-quantity tapping following the start of tapping, the melting chamber side exhaust device 9 and the forming chamber side exhaust device 10 are controlled so that the pressure P2 of the forming chamber 8 becomes higher than the pressure P1 of the vacuum melting chamber 7, and up and down. The tapping is performed in such a manner that the power control of the induction coils 3 and 4 and the power control of the tapping induction coil 5 are used together so that the control of the constant-rate tapping per unit time is extended to a narrow tapping diameter. Further, in the last stage of tapping, power control of the vertical induction coils 3 and 4 and the tapping induction coil 5 are performed.
In addition to the power control described above, the upper and lower exhaust devices 9 and 10 are pressure-controlled so that the pressure P1 in the vacuum melting chamber 7 is higher than the pressure P2 in the molding chamber 8 to shorten the fall time until the end of hot water supply. It is taken out like this.

As described above, when the molten metal 2 is discharged, the power control of the upper and lower induction coils 3 and 4 and the induction coil 5
By using the power control and the pressure control of the melting chamber side exhaust device 9 and the molding chamber side exhaust device 10 together, the rise and fall times can be shortened, and by appropriately selecting the frequency of the tapping induction coil, It is possible to control stably to a smaller tapping diameter than before.

The operations such as starting, stopping, and re-starting the hot water are performed by using both the power control of the upper and lower induction coils 3 and 4 and the pressure control of the exhaust device 9 on the melting chamber side and the exhaust device 10 on the molding chamber side.

FIG. 2 is a block diagram of a main part of an embodiment of the invention according to the second, third, and fourth aspects. FIG. 2 is a cross-sectional view of the nozzle attached to the outlet, from (a) to (g).
(H). As described above, the nozzle 6 is configured by combining 2 to 8 slits and the water-cooled metal, and various nozzles having an inner diameter a are prepared. These slits are for linking the magnetic flux from the tapping induction coil wound around the outer periphery of the nozzle 6 to the tapping flow in the nozzle 6, and the greater the number of slits, the greater the power induced in the tapping flow. Although the other parts of the slit can be made of water-cooled metal, the number of slits is limited due to the water-cooled structure. In addition, an insulator is attached to the slit portion to prevent leakage of hot water from that portion and short-circuit between adjacent water-cooled metals.

Further, by increasing the length h of the nozzle 6, it is possible to reduce the run-out of the tapping flow. However, if the length is made longer than necessary, it is necessary to compensate for the removal of heat from the tapping flow there. It is not a good idea because it is necessary to increase the input.

FIG. 3 is a structural view of a main part of an embodiment of the present invention according to claims 5 and 9, FIG. 4 is a view of a tapping state of FIG. 3, and FIG. Fig. 6
5 shows a tapping state diagram of FIG.

The embodiment shown in FIGS. 3 and 4 is different from the embodiment shown in FIG. 1 in that the operations such as tapping, tapping out, and tapping again are controlled by the power control of the upper and lower induction coils 3 and 4. In contrast to the pressure control of the chamber side exhaust device 9 and the pressure control of the molding chamber side exhaust device 10, the outlet 1b is used.
A tap 20 is provided to block the water from above, and operations such as tapping, stopping the tapping, and tapping again by moving the tap 20 up and down, and an atomizer 16 is provided instead of casting the molten metal 2 into the mold 15. That is, powder metal is manufactured.

In the embodiments of FIGS. 3 and 4, the outlet 1b is covered with the tap 20 from above, but the tap 20 can be attached to and detached from the nozzle 6 as shown in FIGS. It may be attached to. In this manner, the start, stop, and re-start of tapping can be reliably performed, so that atomizing can be performed with high accuracy.

FIG. 7 is a block diagram of a main part of an embodiment of the invention according to claim 6, and FIG. 8 is a tapping state diagram of FIG. The difference between the embodiment of FIGS. 7 and 8 and the embodiment of FIG. 1 is that the embodiment of FIG. Is melted by attaching it to the upper end portion of the nozzle in advance, and when the melting is completed and the tapping is started, the tapping coil 21 is used to melt the material plug 21 and then the tapping is performed. The point is that an atomizer 16 is provided instead of casting into the metal 15 to produce powdered metal.

As described above, when the nozzle 6 is plugged with the plug 21, the molten metal 2 having an insufficient buoyancy at the initial stage of melting may drop, or the molten metal loses the buoyancy due to a power failure during the melting. The molten metal 2 can be prevented from dropping into the molding chamber 8.

FIG. 9 is a block diagram showing a main part of an embodiment of the present invention. The embodiment of FIG. 9 differs from the embodiment of FIG. 1 in that the embodiment of FIG.
, And rapidly cooled to a non-crystallized foil band and wound up by the winder 18.

[0039]

According to the present invention, in a bottom tapping type levitation melting apparatus, a pure metal or alloy melt is maintained in a high purity state or refined to a high purity by a vacuum melting method or the like, and a desired tapping diameter ( In particular, small tapping diameter which has been difficult until now)
This has the effect of controlling hot water supply and flow rate. In addition, it is possible to stop the hot water supply and restart the hot water supply. As a result, for example, castings aimed at a desired cooling rate, non-crystallized bulk or foil strips and ribbons by rapid cooling, and powders with uniform particle diameters (finer with a small tapping diameter) are produced by gas atomizing. There is an effect that can be done.

Further, in gas atomizing, a denser and more uniform alloy molded product can be obtained by incorporating it into a molding process such as spray forming in a later process. Furthermore, since a small tapping diameter can be controlled over a wide range from the start to the end of tapping, there is an effect that it can be applied to various manufacturing and molding processes after melting.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a main part of an embodiment of the invention described in claims 1, 2, 7, and 8;

FIG. 2 is a configuration diagram of a main part of an embodiment of the invention described in claims 2, 3 and 4;

FIG. 3 is a configuration diagram of a main part of an embodiment of the invention described in claims 5 and 9;

FIG. 4 is a view showing a tapping state of FIG. 3;

FIG. 5 is a view in which the tap of FIG. 3 is attached from below.

FIG. 6 is a view showing a tapping state of FIG. 5;

FIG. 7 is a configuration diagram of a main part of the embodiment of the invention described in claim 6;

FIG. 8 is a view showing a tapping state of FIG. 7;

FIG. 9 is a configuration diagram of a main part of the embodiment of the invention described in claim 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal crucible 1a Slit 1b Outflow port 2 Melt 3 Upper induction coil 4 Lower induction coil 5 Induction coil 6 Nozzle 7 Vacuum melting room 8 Molding room 9 Melting room side exhaust device 10 Molding room side exhaust device 11 Partition jacket 12,13 Power supply 14 Power supply for tapping coil 15 Mold 16 Atomizer 17 High-speed rotating twin roll 18 Winding machine 20 Tapping tap 21 Both taps

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B22D 45/00 B22D 45/00 B 4K063 B22F 9/08 B22F 9/08 A C22C 1/02 501 C22C 1 / 02 501F 501E F27D 11/06 F27D 11/06 A H05B 6/32 H05B 6/32 // C21C 7/10 C21C 7/10 LF term (reference) 3K059 AA08 AA10 AB07 AB16 AC09 AC12 AC76 AC78 AD04 BD04 CD18 CD48 CD52 CD62 CD72 CD77 4E004 DB03 MB11 TA01 TB07 4K013 AA00 CD04 CE00 4K017 AA03 BA10 CA01 EB04 EB05 EB10 FA02 FA03 4K046 AA01 BA03 CC01 CD02 EA03 4K063 AA04 BA03 CA06 FA34 FA44 FA48

Claims (10)

[Claims] 1. A metal crucible having a plurality of radial slits in a radial direction, an outlet for discharging molten metal at a bottom portion, a nozzle attached to the outlet, and an induction coil for tapping on an outer peripheral side of the nozzle. In the flotation / melting apparatus for performing fusing / melting and tapping from an outlet, a frequency of a current applied to the induction coil for tapping is a predetermined frequency in a range of 100 KHz to 500 KHz. 2. A bottom tapping type flotation and melting apparatus according to claim 1, wherein nozzles having different hole diameters or lengths corresponding to a desired tapping amount or tapping diameter or a necessary length for maintaining the tapping diameter are provided. Bottom tapping type flotation melting device characterized by replacement. 3. The bottom tapping type floatation and melting apparatus according to claim 1 or 2, wherein the nozzle is water-cooled. 4. The bottom tapping type flotation and melting apparatus according to claim 1, wherein the nozzle has one or more vertical slits. 5. A bottom tapping type flotation melting apparatus according to any one of claims 1 to 4, further comprising a tap with a drive device that opens and closes an outlet from an upper portion or a lower portion. Starting or stopping hot water by vertical movement,
A bottom tapping type flotation / melting apparatus characterized by performing tapping again. 6. A bottom tapping type flotation melting apparatus according to any one of claims 1 to 4, wherein a material stopper is provided so as to cover the nozzle hole even if the material is made of the same material as the melting material. A bottom tapping type flotation melting apparatus characterized in that at the time of tapping, a tapping induction coil on the outer peripheral side of the nozzle melts the plug and starts tapping. 7. A metal crucible according to any one of claims 1 to 6, further comprising a molding chamber for processing the molten metal under a vacuum at a lower portion of the nozzle, wherein the metal crucible is provided. An induction coil for levitation and melting, a nozzle attached to the outlet, a vacuum melting chamber containing the induction coil for tapping and having a lower part partitioned by a partition wall, and a forming chamber for processing the molten metal melted in the metal crucible under vacuum. Having a passage hole that abuts the lower end of the nozzle and allows the hot water flow to pass therethrough,
A partition jacket is provided through the partition wall so that air can flow between the upper and lower chambers only through the passage hole, and a vacuum evacuation system is provided in each of the vacuum melting chamber and the molding chamber. Bottom tapping type flotation melting device. 8. The bottom tapping type flotation and melting apparatus according to claim 7, wherein the power supplied to the flotation induction coil is controlled to control the tapping diameter, tapping, and stop of tapping, and a vacuum melting chamber and molding. The control for generating a pressure difference in the vacuum pressure of the chamber to apply a squeezing force to the tapping flow is used together with the control to add the squeezing force to the tapping flow by controlling the power or frequency applied to the tapping induction coil. Bottom tapping type flotation melting apparatus characterized by the above-mentioned. 9. The bottom tapping type flotation melting apparatus according to claim 7 or 8, wherein the forming chamber is provided with an atomizer for spraying a gas toward the tapping water stream to generate powder metal. Bottom tapping type flotation melting device. 10. A bottom tapping type flotation melting apparatus according to claim 7 or 8, wherein an amorphous bulk,
Alternatively, a bottom tapping type flotation melting apparatus characterized by providing a rapid cooling and solidifying mechanism for producing a foil strip.