JP4267093B2 - Molten metal pumping device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a molten metal pumping apparatus for pumping molten metal such as aluminum or aluminum alloy melted in a crucible from a crucible and transferring it to another container.
[0002]
[Prior art]
Conventionally, as a means for pumping and transferring a molten metal such as aluminum from a crucible, as disclosed in Japanese Utility Model Publication Nos. 47-40405 and 61-70580, a piston or a plunger is used in the cylinder. A reciprocating pump that reciprocates and pumps molten metal, or a rotary pump that pumps by rotating a rotor with a motor as disclosed in Japanese Utility Model Publication No. 49-12463 has been put to practical use.
[0003]
[Problems to be solved by the invention]
The above-described pump-type molten metal pumping means has movable members such as pistons and rotors as indispensable components, so that the structure becomes complicated and the movable member is immersed in high-temperature molten metal. The durability is low.
In view of the above, an object of the present invention is to provide a molten metal pumping apparatus that does not require a movable member immersed in molten metal, has a simple structure, and is excellent in durability.
[0004]
[Means for Solving the Problems]
According to the first aspect of the present invention, a molten metal suction pipe is suspended at the bottom of the tank, a hot water reservoir for accumulating the molten metal is connected to the lower end of the suction pipe, and a vacuum pump is connected to the upper part of the tank. Provided with an atmospheric port communicating with the atmosphere and an opening / closing valve for opening and closing each port, a vacuum regulating valve is disposed between the vacuum pump and the vacuum port, and the suction pipe is immersed in the molten metal Then, the inside of the tank is set to a predetermined vacuum pressure set by the vacuum control valve, the molten metal is sucked into the tank, the tank is transferred to the tank while keeping the inside of the tank at the predetermined vacuum pressure, and the tank is opened to the atmospheric pressure. A molten metal pumping device configured to discharge the molten metal from the suction pipe,
The hot water reservoir has a cylindrical structure having a bottom, a small-diameter hollow portion and a large-diameter hollow portion adjacent to the bottom are formed inside, and a large-diameter from an upper end surface opening of the small-diameter hollow portion on an inner peripheral surface of the small-diameter hollow portion. A communication path that leads to the hollow portion is formed, and a thread that attaches the sump to the lower end of the suction pipe is formed on the inner peripheral surface of the small-diameter hollow part by screwing with a thread formed on the outer periphery of the lower end of the suction pipe. It is characterized by that.
[0005]
[Operation and effect of the invention]
In order to pump the molten metal with the molten metal pumping apparatus according to claim 1, the tip of the suction pipe is immersed in the molten metal in the crucible, the atmospheric port is closed, the vacuum port is opened, and the vacuum pump is operated. Then, air is discharged from the inside of the tank, and the inside of the tank is reduced to a predetermined vacuum pressure set by a vacuum control valve. When the inside of the tank reaches a vacuum pressure, the molten metal in the crucible is sucked into the tank through the suction pipe due to the differential pressure between the atmospheric pressure acting on the molten metal in the crucible and the vacuum pressure in the tank. Since the suction from the crucible automatically ends when the molten metal accumulates in the tank to a height corresponding to the differential pressure between the atmospheric pressure and the vacuum pressure set by the vacuum control valve, the suction pipe is kept crucible while the vacuum pump is still operated. Pull the tank away from the molten metal and transfer the tank to another container. During the transfer, the inside of the tank is maintained at a predetermined vacuum pressure by the vacuum regulating valve, so that the molten metal does not drip from the tank. When the vacuum port is closed and the atmospheric port is opened after the transfer of the tank, the inside of the tank is opened to the atmospheric pressure, so that the molten metal is discharged from the tank to another container through the suction pipe.
[0006]
According to the molten metal pumping apparatus according to claim 1, since movable members such as pistons and rotors that are indispensable for various types of pumps are not required, the structure becomes extremely simple, low cost, and high durability. A means for pumping molten metal can be obtained.
In particular, in the present invention, a vacuum adjusting valve is provided to adjust the inside of the tank to a predetermined vacuum pressure, so that the amount of molten metal sucked into the tank from the crucible can be maintained properly and the airtightness of the tank is reduced during transfer. Thus, it is possible to prevent the molten metal from dripping from the suction pipe.
[0007]
In addition, since a hot water reservoir is provided at the lower end of the suction pipe, when the suction pipe is pulled away from the molten metal in the container and the tank is transferred to another container, the molten metal accumulates in the hot water reservoir, thereby opening the lower end of the suction pipe. Air can be prevented from entering the tank.
When air enters the tank through the suction pipe during tank transfer, the vacuum pressure inside the tank decreases, the pressure difference inside and outside the tank decreases, and molten metal in the tank drops from the suction pipe. Since the intrusion of air from the suction pipe can be prevented, dripping of the molten metal can be reliably prevented in combination with the function of the vacuum control valve.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to the drawings. FIG. 1 shows a molten metal pumping apparatus 10 according to an embodiment of the present invention. The molten metal pumping device 10 is for pumping molten aluminum 12 from a crucible 11 and includes a tank 13. In this tank 13, a refractory container 14 is placed in an iron case 15, sand 16 is filled between the iron case 15 and the refractory container 14, and the upper surface opening of the iron case 15 is covered with an iron lid 17. It is configured.
[0009]
A suction pipe 18 is suspended from the bottom of the refractory container 14 and protrudes from the bottom surface of the iron case 15. A screw thread is formed on the outer periphery of the lower end portion of the suction pipe 18, and a hot water reservoir 19 for storing molten aluminum is attached to the screw thread.
[0010]
As shown in FIGS. 2 and 3, the hot water reservoir 19 has a cylindrical structure having a bottom, a small-diameter hollow portion 20 and a large-diameter hollow portion 21 formed therein, and a screw that is screwed into the thread of the suction pipe 18. A peak 22 is formed on the inner peripheral surface of the small-diameter hollow portion. Further, four communication passages 23 having a semicircular cross section are formed on the inner peripheral surface of the small-diameter hollow portion 20 from the upper end surface opening of the small-diameter hollow portion 20 to the large-diameter hollow portion 21.
[0011]
The iron lid 17 is provided with a vacuum port 25 connected to the vacuum pump 24 and an atmospheric port 26 communicating with the atmosphere, and an opening / closing valve 27 for opening and closing each port 25, 2 in a pipeline connected to each port 25, 26. , 28 are provided. A vacuum adjustment valve 31 is disposed between the on-off valve 27 and the vacuum port 25.
[0012]
An O-ring 29 is interposed between the iron lid 17 and the iron case 15 to maintain airtightness. Further, a mortar 30 having sealing properties is filled between the iron case 15 and the upper end portion of the refractory container 14 and between the iron case 15 and the bottom portion of the refractory container 14.
[0013]
The structure of the molten metal pumping apparatus 10 according to the present embodiment is as described above, and the operation thereof will be described below.
The hot water reservoir 19 attached to the tip of the suction pipe 18 is immersed in the molten aluminum 12 in the crucible 11, the atmospheric port 26 is closed, the vacuum port 25 is opened, and the vacuum pump 24 is operated to draw air from the inside of the tank 13. Then, the inside of the tank 13 is reduced to a predetermined vacuum pressure set by the vacuum control valve 31.
[0014]
When the inside of the tank 13 reaches a vacuum pressure, as shown in FIG. 4, the molten aluminum 12 in the crucible 11 is moved into the sump 19 by the differential pressure between the atmospheric pressure acting on the molten aluminum 12 in the crucible 11 and the vacuum pressure in the tank 13. The air is sucked into the refractory container 14 of the tank 13 from the communication passage 23 through the suction pipe 18. When the molten aluminum 12 accumulates in the refractory container 14 of the tank 13 to a height corresponding to the differential pressure between the atmospheric pressure and the predetermined vacuum pressure, the suction from the crucible 11 is finished.
[0015]
When the inside of the tank is temporarily set to a Tricheno vacuum (−0.1013 MPa) by the vacuum control valve 31, the specific gravity is sucked to a height of 76 cm with mercury of 13.5 g / cc. Accordingly, the molten aluminum 12 having a specific gravity of about 2.2 g / cc is sucked to a height of about 466 cm (= 76 cm × 13.5 / 2.2). When the height from the lower end portion of the suction pipe 18 to the upper end surface of the refractory container 14 is set to about 70 cm, the tank internal pressure is set to −0.015 MPa (= −0.1013 MPa × 70 cm / 466 cm) by the vacuum control valve. Then, the molten aluminum 12 can be prevented from overflowing from the refractory container 14.
[0016]
When the suction into the refractory container 14 is completed, the vacuum pump 24 is continuously operated to keep the internal pressure of the tank 13 at a predetermined vacuum pressure, and the tank 13 is raised as shown in FIG. Pull away from the molten aluminum 12, and transfer the tank 13 to another container. Therefore, the on-off valves 27 and 28 are operated to close the vacuum port 25 and open the atmospheric port 26. Then, the inside of the tank 13 is opened to the atmospheric pressure and the pressure difference between the inside and outside of the tank 13 is eliminated, so that the molten aluminum 12 is discharged from the refractory container 14 of the tank 13 through the suction pipe 18 to another container.
[0017]
According to the molten metal pumping apparatus 10 according to the present embodiment, movable members such as pistons and rotors that are indispensable for various types of pumps are not required, so the structure becomes extremely simple, low cost, and high durability. A means for pumping molten aluminum can be obtained.
Further, since the inside of the tank 13 is adjusted to a predetermined vacuum pressure by providing the vacuum adjustment valve 31, the amount of the molten aluminum 12 sucked into the tank 13 from the crucible 11 can be kept constant, and the tank 13 is transferred at the time of transfer. Therefore, it is possible to prevent molten aluminum from dripping from the suction pipe 18.
[0018]
Furthermore, since the hot water reservoir 19 is provided at the lower end of the suction pipe 18, when the suction pipe 18 is pulled away from the molten aluminum in the crucible 11 and the tank 13 is transferred to another container, the molten aluminum is accumulated in the hot water reservoir 19 and this. Thus, air can be prevented from entering the inside of the tank 13 from the lower end opening of the suction pipe 18.
Thus, when air enters the tank 13 through the suction pipe 18 when the tank 13 is transferred, the vacuum pressure inside the tank 13 decreases, the pressure difference inside and outside the tank 13 decreases, and the molten aluminum 12 in the tank 13 sucks. Although dripping from the pipe 18, it is possible to prevent the intrusion of air by providing the hot water reservoir 19, so that it is possible to ensure that the molten aluminum 12 is dripped in combination with keeping the tank internal pressure at a predetermined vacuum pressure by the vacuum adjustment valve 31. Can be prevented.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a molten metal pumping apparatus according to an embodiment of the present invention.
FIG. 2 is a plan view of a sump as seen from line 2-2 in FIG.
3 is a cross-sectional view of a sump taken along line 3-3 in FIG. 2. FIG.
FIG. 4 is a cross-sectional view showing the operation of the molten metal pumping apparatus according to one embodiment of the present invention.
FIG. 5 is a sectional view for explaining the operation of the molten metal pumping device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Molten metal drawing-out apparatus, 12 ... Molten aluminum, 13 ... Tank, 14 ... Refractory container, 18 ... Suction pipe, 19 ... Hot water reservoir, 24 ... Vacuum pump, 25 ... Vacuum pressure port, 26 ... Atmospheric pressure port, 27, 28 ... Open / close valve, 31 ... Vacuum adjustment valve.

Claims (1)

A molten metal suction pipe is provided vertically at the bottom of the tank, a hot water reservoir for storing the molten metal is provided at the lower end of the suction pipe, and communicated with the vacuum port connected to the vacuum pump and the atmosphere at the top of the tank. An atmospheric port and an opening / closing valve for opening and closing each port are provided, a vacuum regulating valve is disposed between the vacuum pump and the vacuum port, the suction pipe is immersed in molten metal, and the inside of the tank is filled with the vacuum regulating valve. The molten metal is sucked into the tank at a predetermined vacuum pressure that has been set, the tank is transferred while the tank interior is maintained at the predetermined vacuum pressure, and the molten metal in the tank is released from the suction pipe by opening the tank to atmospheric pressure. A molten metal pumping device adapted to discharge ,
The hot water reservoir has a cylindrical structure having a bottom, a small-diameter hollow portion and a large-diameter hollow portion adjacent to the bottom are formed inside, and a large-diameter from an upper end surface opening of the small-diameter hollow portion on an inner peripheral surface of the small-diameter hollow portion. A communication path that leads to the hollow portion is formed, and a thread that attaches the sump to the lower end of the suction pipe is formed on the inner peripheral surface of the small-diameter hollow part by screwing with a thread formed on the outer periphery of the lower end of the suction pipe. Molten metal pumping device characterized by being made .

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