JP2001047217A - Method for transferring molten metal and portable pump used for transfer thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for easily and suitably transferring molten metal from a furnace to a mold without exposing it to the atmosphere. SOLUTION: A heat resistant vessel 2 is hung with a hoist device 4, and a nozzle 6 formed at the bottom part thereof, is inserted into the molten metal M. Then, the molten metal M is sucked while sucking inert gas in the heat resistant vessel 2 to reduce the pressure in the inner part thereof, and when a prescribed quantity of the molten metal M is completely sucked, while keeping the reduced pressure state in the heat resistant vessel 2, the molten metal is transferred to above the mold with the hoist device 4. Thereafter, the inert gas is again poured into the heat resistant vessel 2 and the molten metal M is caused to flow out from the nozzle 6. In this way, the molten metal M can be cast in a state of scarcely exposing it to the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for transferring molten aluminum, magnesium, copper, or other molten metal without contact with the atmosphere.

[0002]

2. Description of the Related Art Generally, metals are melted in ore in a smelting furnace, and the obtained molten metal is charged into an electric furnace or a converter for refining, and is transferred to a ladle for casting. Dissolution and refining in the atmosphere are more or less contaminated by oxygen, hydrogen, water vapor, or the like, and the quality of the material is often reduced. In particular, when the molten metal is transferred from a converter or the like to a ladle, there is a lot of contact with the atmosphere, and the oxide is suspended as a film on the ladle before casting. For this reason, when scooping and pouring the molten metal in the ladle with a ladle, it is necessary to eliminate oxides floating on the molten metal and prevent its mixing. However, this kind of work is performed by humans in a poor environment, and the physical burden is large and danger is likely to occur. In addition, in a large-scale facility, an automatic system in which the molten metal is poured directly from the bottom of the ladle into the mold is employed, but it is extremely difficult to prevent the progress of oxidation of the molten metal in the ladle. Further, a method of degassing from a molten metal in a ladle by applying a DH vacuum degassing method or the like is often used, but such a treatment requires not only large-scale equipment but also takes time.

Therefore, Japanese Patent Application Laid-Open No. 3-264155 proposes a pump capable of transporting a molten metal from a tank to a mold or the like without bringing the molten metal into contact with the atmosphere.

[0004]

However, such a pump requires a long pipe line for transporting the molten metal, and all of the pumps must have a heat-resistant structure, so that the equipment cost is increased. is there. In addition, since the flow of the molten metal is controlled by operating the valve, malfunctions are likely to occur. In particular, since the valve body is exposed to the molten metal, high heat resistance is required. The function is impaired and the flow of the molten metal cannot be properly controlled.

Accordingly, an object of the present invention is to provide a simple method and apparatus which can easily and properly transfer a highly oxidizable metal melt such as aluminum without exposing it to the atmosphere.

[0006]

In order to achieve the above object, the present invention has a capacity capable of storing a required amount of molten metal and a nozzle formed at the bottom for taking in and out the molten metal. Uses a heat-resistant container having a resistance to prevent the outflow of the molten metal by its surface tension, suspends the heat-resistant container so that it can be transferred on the molten metal, and places an inert gas in the heat-resistant container. After the nozzle is inserted into the molten metal in a state filled with, the pressure inside the heat-resistant container is reduced while the inert gas is sucked out from the upper portion thereof, and the molten metal is sucked into the heat-resistant container through the nozzle, Transferring the heat-resistant container to a predetermined position while suspending the heat-resistant container while keeping the inside of the heat-resistant container under reduced pressure, and then re-injecting the inert gas into the heat-resistant container, and causing the molten metal to flow out of the nozzle at the pressure. Provides a method of transferring molten metal, characterized.

In addition, a nozzle for insertion into the molten metal is formed at the bottom, and a heat-resistant container which is held so as to be able to be transferred by a suspending means is provided, and the heat-resistant container is passed through the nozzle by adjusting the pressure in the heat-resistant container. A heat-resistant container having a vent connected to pressure regulating means at an upper part thereof, and a heat-resistant container provided in a flow path formed inside the nozzle. When the inside is kept at a constant reduced pressure state by the pressure adjusting means, a porous partition plate is provided which disables the outflow of the molten metal stored in the heat-resistant container. Provided is a portable pump used for transfer.

In particular, the pressure adjusting means comprises a cylinder connected to the vent of the heat-resistant container, a piston reciprocating while being in close contact with the inner wall of the cylinder, and a drive source for reciprocating the piston in the cylinder. Is done.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 1, reference numeral 1 denotes a bath, such as a converter, an electric furnace, or a ladle for transferring molten metal obtained in a heating furnace thereof, and 2 denotes a bath for sucking up and temporarily storing the molten metal in the bath. The heat-resistant container 3 is a supply / exhaust device as a pressure adjusting means for adjusting the pressure in the heat-resistant container, and the hoist device 4 is a suspension means for suspending and transferring the heat-resistant container.

The heat-resistant container 2 has a volume (for example, 0.5 to 10) capable of storing a required amount of the molten metal M therein.
m ³ ), the inner wall of which is lined with a refractory material mainly composed of silicon or the like to form a storage room 5. Further, the bottom of the heat-resistant container 2 is a funnel-shaped nozzle 6 inserted into the molten metal stored in the hot water bath 1, and a flow path 7 for passing the molten metal is formed in an inner peripheral portion thereof. The nozzle 6 is formed by an upper pipe 6A integrally connected to a lower end opening of the container main body 2A forming the storage chamber 5, and a detachable lower pipe 6B connected to the upper pipe. Is provided with a partition plate 8 for partitioning the flow path 7. These members are formed of carbon, silicon carbide, silicon nitride, or other refractory material, and can be removed and replaced from the container body 2A by, for example, loosening a fastening bolt at the time of corrosion or the like.

On the other hand, a supply / exhaust device 3 is provided above the heat-resistant container 2.
Is provided with a vent hole 9 connected to the air outlet. When the atmosphere in the heat-resistant container 2 is sucked out by the air supply / exhaust device 3 through the vent 9, the metal melt is sucked into the storage chamber 5 in the heat-resistant container through the nozzle 6 inserted into the metal melt, and conversely, the supply When gas for pressurization is sent from the exhaust device 3 into the heat-resistant container 2 through the vent 9, the molten metal stored in the storage chamber 5 is discharged from the nozzle 6 to the outside. That is, the gas is supplied and exhausted from the ventilation port 9 by the air supply / exhaust device 3 to depressurize (negative pressure) or pressurize (positive pressure) the storage chamber 5.
By performing such pressure adjustment, it is possible to cause the molten metal to flow into the storage chamber 5 from the nozzle 6 through the partition plate 8 therein, and to flow the molten metal from the storage chamber 5.

Here, the supply / exhaust device 3 comprises a piston engine. More specifically, it is composed of a cylindrical cylinder 10, a piston 11 that reciprocates along its longitudinal direction while being in close contact with the inner wall of the cylinder, and a motor 12 as a drive source that reciprocates the piston. The lower end of the cylinder 10 is fixed to a pedestal 14 attached to a frame 13, and a pressure chamber 15 whose volume is changed by a piston 11 is formed above the cylinder 10, and the pressure chamber is connected via an air hose 16. It is connected to the vent 9 of the heat-resistant container.

The piston 11 has a piston ring (not shown) mounted on its outer periphery to keep the pressure chamber 15 airtight, and is operated via a piston rod 17 connected to the lower surface thereof. The piston rod 17 has a screw shaft, one end of which is connected to rotate relative to the piston 11 via a rotary joint (not shown), and the other end of which penetrates a nut 18 provided on the pedestal 14. The dog 19 is fixed to the end of. The nut 18 is rotatably mounted on the pedestal 14 while its movement in the axial direction is restricted.
Is fixed. An endless transmission belt 22 such as a chain or a timing belt is looped around the drive wheel 20 and a drive wheel 21 mounted on a drive shaft of the motor 12.

The frame 13 is provided with detectors 23A and 23B for defining the movable range of the piston 11 along the axial direction of the piston rod 17, respectively. Each of the detectors 23A and 23B is composed of, for example, a limit switch.
And the motor 12 can be stopped. According to the supply / exhaust device 3 configured as described above, the piston 11 is reciprocated up and down via the piston rod 17 by the forward / reverse rotation of the motor 12, whereby gas is exchanged with the heat-resistant container 2. Exchange to enable pressure adjustment of the storage room 5.

In order to prevent the piston 11 and the piston rod 17 from spinning when the nut 12 is driven to rotate by the motor 12, for example, a ridge is formed on the inner wall of the cylinder 10 along the operation direction of the piston 11, while the outer periphery of the piston 11 is formed. It is preferable to form a notch groove that matches the ridge. Of course,
As another means, the cylinder 10 and the piston 11 may be made non-circular.

Next, the hoist device as a suspending means for suspending the heat-resistant container will be described in detail. The hoist device 4 is provided, for example, as shown in FIG. Configured as an overhead crane. The hoisting device 24 is formed by integrating a winding drum, a speed reducer, a prime mover, and the like (not shown). According to this, the hoisting device 24 travels along the rail 25 with the heat-resistant container 2 suspended. Can be transferred to a predetermined position, for example, on a mold for casting a molten metal. In particular, the hoisting device 24 has a latch 26 for hanging the heat-resistant container 2, and a connection fitting 27 for hanging the latch 26 is attached to the upper part of the heat-resistant container 2. When the heat-resistant container 2 is transferred, the air supply / exhaust device 3 is fixed to a predetermined position while being connected to the heat-resistant container 2 by the air hose 16. it can.

Here, the operation of the present pump configured as described above will be described. First, when taking out the molten metal M in the hot water tank 1, the heat-resistant container 2 suspended by the hoist device 4 is moved above the molten metal M, and the heat-resistant container 2 is gradually lowered while the hoist device 4 is remotely controlled. Insert the tip into the molten metal. Of course, the hot tub 1 may be raised. However, since the hot tub 1 is generally a fixed type, the heat-resistant container 2 side is lowered so that the nozzle 6 can be inserted into the molten metal.

At this time, the storage chamber 5 in the heat-resistant container 2 is previously filled with an inert gas such as argon or nitrogen. For example, a bypass 28 branched from the air hose 16
The inner valve 29 is opened to guide the inert gas from the air hose 16 through the vent 9 into the storage chamber 5. The inert gas supplied into the storage chamber 5 flows out of the tip of the nozzle 6 through the partition plate 8. After the inert gas is filled in the storage chamber 5, the inert gas is quickly inserted into the molten metal to make the inert gas inert. The outflow of gas can be kept very small. When the nozzle 6 is inserted, the nozzle 6 is inserted obliquely with respect to the molten metal surface L in order to prevent outside air from being introduced into the storage chamber 5 due to the insertion pressure, or the nozzle 6 is inserted into the storage chamber 5. It is desirable to keep the pressure slightly higher than the outside pressure (atmospheric pressure). For example, the nozzle 6 may be inserted into the molten metal while pulling the side surface of the heat-resistant container 2 with a rope, or may be inserted while supplying an inert gas.

Thus, when the nozzle 6 is inserted into the molten metal, the air supply / exhaust device 3 is operated to suck out the inert gas filling the storage chamber 5, whereby the inside of the heat-resistant container 2 is depressurized and stored from the nozzle 6. The molten metal M is caused to flow into the chamber 5.
In other words, the motor 12 of the air supply / exhaust device 3 is rotated in one direction to lower the piston 11, and the inert gas in the storage chamber 5 that communicates airtightly while increasing the volume of the pressure chamber 15 is supplied to the pressure chamber 1.
Pull in to 5. As a result, the molten metal M in the hot water bath placed in the atmosphere is sucked into the storage chamber 5 where the pressure is reduced below the atmospheric pressure at a speed proportional to the movement of the piston 11.

When the required amount of the molten metal has been sucked into the storage room 5, the interior of the storage room 5 is maintained in a reduced pressure state, that is, the piston 11 is fixed at a fixed position and the inert gas is introduced into the storage room 5. The heat-resistant container 2 is lifted in a state in which is prevented from flowing in, and is transported to a predetermined position, for example, on a mold while being suspended by the hoist device 4.

Since the piston 11 is moved in the axial direction by rotation of a piston rod 17 formed as a screw shaft, the piston 11 can be fixed only by stopping the motor 12. Also, the flow path 7 in the nozzle 6 allows the molten metal stored in the inside to flow out while the storage chamber 5 is kept at a constant reduced pressure state even after the nozzle 6 is pulled out of the molten metal. Has a resistance that can prevent the That is, the channel 7 has an opening ratio such that the molten metal is prevented from flowing out due to its surface tension. For this purpose, the flow path 7 may be formed as a single ultrafine tube. In the present invention, in particular, the diameter of the flow path 7 is increased to the maximum so that lifting and discharging of the molten metal can be performed efficiently. The porous partition plate 8 (screen) as described above is interposed.

The partition plate 8 is made of a plate material having a diameter slightly larger than the diameter of the flow path 7 and a thickness of several mm to several tens mm, and between the upper pipe 6A and the lower pipe 6B as described above. It is to be sandwiched and held. The partition plate 8 functions as a check valve for preventing the molten metal stored in the storage chamber 5 from flowing out while the inside of the storage chamber 5 is kept in a reduced pressure state.

FIG. 2 is a plan view showing the surface partially enlarged. As is clear from this figure, a plurality of rectangular small holes 31 defined by ribs 30 are formed in the partition plate 8.
Is formed. The size of the small hole 31 is set to an optimum value according to the type of the molten metal and the volume of the heat-resistant container. For example, the height of the heat-resistant container 2 is 500 mm, the diameter of the flow path 7 is 50 mm, and the molten metal is made of aluminum. In this example, the width of the rib 30 is 0.5 mm, and the small hole 31 is a square hole having a side of 2 mm. Of course, this is an example, and the partition plate 8
The size of the small hole 31 and the opening ratio are the height of the heat-resistant container 2,
The volume is set in consideration of the volume and the volume of the molten metal.

Thus, the heat-resistant container 2 is guided to the mold without causing the molten metal stored in the storage chamber 5 to flow out of the nozzle 6 by the reduced pressure of the air supply / exhaust device 3 and the interaction with the partition plate 8. become. Therefore, this time the air supply and exhaust system 3
, The inert gas in the pressure chamber 15 is returned to the storage chamber 5. That is, the motor 12 is rotated in the reverse direction to rotate the piston 11
Is raised, whereby the inert gas is re-injected into the storage chamber 5 from the vent 9 while reducing the volume of the pressure chamber 15. Then, the pressure in the storage room 5 rises, and the pressure is increased by the surface tension of the molten metal (resistance of the molten metal flowing out of the partition plate).
Sufficiently, the molten metal stored in the storage chamber 5 is discharged from the tip of the nozzle 6 in proportion to the operation amount of the piston 11. Therefore, if the above operation is performed with the nozzle 6 positioned at the gate of the mold,
Until the molten metal is cast, it hardly comes into contact with the outside air, so that deterioration due to oxidation can be prevented. When all of the molten metal has been discharged, the heat-resistant container 2 is moved to the hot water tank 1 again. At this time, a film of the molten metal is formed on the partition plate 8 so that the film completely closes the flow path 7. Therefore, the outflow of the inert gas is prevented, and this can be used repeatedly.

According to the supply / exhaust device 3 as described above, the flow rate of the molten metal can be controlled by the operation amount of the piston 11 and the inert gas can be used repeatedly. Although a promising adjusting means, a known vacuum generating device such as a vacuum pump can be used for this. In this case, an exhaust system for decompression is formed by a vacuum generator connected to the ventilation port 9, and an air supply port (not shown) is formed in the upper part of the heat-resistant container 2 separately from the ventilation port 9. An air supply system for pressurizing the storage chamber 5 can be formed by connecting an inert gas tank to the mouth or the like. In addition, it is necessary to interpose an electromagnetic valve or the like between the two systems so that the gas path can be cut off when the molten metal is transferred by the heat-resistant container 2.

On the other hand, a manipulator or the like can be used as the suspension means in addition to the overhead crane. The manipulator referred to here is an arm including a robot arm and a jib crane. In the above example, the molten metal is transferred to the mold, but it goes without saying that a die casting machine or the like can be freely selected as a transfer destination. Aluminum, magnesium, copper, and the like can be used as the molten metal.

[0027]

As is clear from the above description, according to the present invention, since the molten metal in the furnace or the like is transferred to the mold or the like while being sucked into the heat-resistant container, the oxides A good quality casting can be produced with as little production as possible.
In particular, since the nozzle is inserted into the molten metal and sucked up, no oxide floating on the surface of the furnace is sucked in, and the molten metal is transferred into a heat-resistant container. This eliminates the need for heat-resistant piping equipment unlike conventional pumps, and can greatly reduce equipment costs and running costs. In addition, since there is no mechanical working part in the contact part with the molten metal and it is possible to control the inflow and outflow of the molten metal to and from the heat-resistant container, there is no malfunction, and a simple structure allows the molten metal to be properly formed. Can be transported.

Further, as a pressure adjusting means in the heat-resistant container,
The use of a piston engine makes it possible to easily and accurately control the flow rate of molten metal in and out of the heat-resistant container, and to repeatedly use the inert gas injected into the heat-resistant container without wasting it. It is possible.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a preferred example of a portable pump according to the present invention.

FIG. 2 is a partially enlarged plan view showing a partition plate used in the apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hot water tank 2 Heat-resistant container 3 Supply / exhaust device 4 Hoist device 5 Storage room 6 Nozzle 7 Channel 8 Partition plate 9 Vent 10 Cylinder 11 Piston 12 Motor 15 Pressure chamber 30 Rib 31 Small hole

Claims (3)

[Claims] 1. A nozzle having a capacity capable of storing a required amount of molten metal and having a nozzle formed at the bottom for taking in and out the molten metal, and a flow path in the nozzle can prevent the outflow of the molten metal by its surface tension. Using a heat-resistant container having such a resistance, the heat-resistant container is suspended so that it can be transported on the metal melt, and the nozzle is inserted into the metal melt with the heat-resistant container filled with an inert gas. Then, in this state, the inside of the heat-resistant container is depressurized while sucking out the inert gas from the upper part thereof, and the molten metal is sucked into the heat-resistant container through the nozzle. A method of transferring a molten metal, wherein the molten metal is re-injected into a heat-resistant container, and the molten metal is caused to flow out of the nozzle at the pressure. 2. A heat-resistant container, which is formed at the bottom for insertion into the molten metal and is held by a suspending means so as to be able to be transferred, and the pressure in the heat-resistant container is adjusted through the nozzle to adjust the pressure in the heat-resistant container. A heat-resistant container having a vent connected to pressure regulating means at an upper part thereof, and a heat-resistant container provided in a flow path formed inside the nozzle. When the inside is kept at a constant reduced pressure state by the pressure adjusting means, a porous partition plate is provided which disables the outflow of the molten metal stored in the heat-resistant container. Portable pump used for transfer. 3. The pressure adjusting means comprises a cylinder connected to a vent of the heat-resistant container, a piston reciprocating while closely contacting an inner wall of the cylinder, and a drive source for reciprocating the piston in the cylinder. 3. A portable pump used for transferring molten metal according to claim 2.