JP2000042723A - Device for ladling out molten metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molten metal ladle-out device having simple structure and excellent durability without needing a movable member dipped into molten metal. SOLUTION: A molten metal pool part 19 fitted to the tip part of a sucking tube 18 is dipped into the molten metal 12 in a crucible 11, and an atmosphere port 26 is closed and a vacuum port 25 is opened and the air is exhausted from the inner part of a tank 13 by working a vacuum pump 24. The pressure in the tank 13 is reduced to a prescribed setting vacuum pressure with a vacuum adjusting value 31 and the molten metal 12 in the crucible 11 is sucked into a refractory vessel 14 in the tank 13 from a communicating passage in the molten metal pool part 19 through a suction tube 18 with the differential pressure between atmospheric pressure and vacuum pressure in the tank 13. The sucked molten metal 12 is transported under condition of holding the inner pressure of the tank 13 to the prescribed vacuum pressure and successively, the inner part of the tank 13 is opened to the atmospheric pressure and the molten metal is discharged from the tank 13 by eliminating the differential pressure between the inner side and the outer side of the tank 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten metal pumping apparatus which draws out a molten metal such as aluminum or aluminum alloy melted in a crucible from a crucible and transfers it to another container.

[0002]

2. Description of the Related Art Conventionally, as a means for pumping molten metal such as aluminum from a crucible and transferring it, Japanese Utility Model Laid-Open Publication No.
And a reciprocating pump for pumping molten metal by reciprocating a piston or plunger in a cylinder, as disclosed in Japanese Utility Model Application Publication No. 61-70580.
As disclosed in Japanese Patent Application Laid-Open No. 9-12643, a rotary pump for pumping by rotating a rotor with a motor has been put to practical use.

[0003]

The above-mentioned pump-type molten metal pumping means has a movable member such as a piston or a rotor as an indispensable component, so that the structure becomes complicated and the movable member has a high temperature. Since it is immersed in the molten metal, it is easy to break down and has low durability.
In view of the above, an object of the present invention is to provide a molten metal pumping apparatus which does not require a movable member immersed in molten metal, has a simple structure, and has excellent durability.

[0004]

According to the first aspect of the present invention, a suction pipe of molten metal is vertically provided at the bottom of a tank, and a vacuum port connected to a vacuum pump and an atmosphere communicating with the atmosphere are provided at the top of the tank. A port is provided and an opening / closing valve for opening and closing each port is provided.A vacuum adjusting valve is arranged between the vacuum pump and the vacuum port, the suction pipe is immersed in molten metal, and the inside of the tank is set with the vacuum adjusting valve. The molten metal is sucked into the tank at a predetermined vacuum pressure, the tank is transferred while maintaining the inside of the tank at the predetermined vacuum pressure, and the inside of the tank is opened to the atmospheric pressure to discharge the molten metal in the tank from the suction pipe. It is characterized by doing. According to a second aspect of the present invention, in the molten metal pumping apparatus according to the first aspect, a sump for storing the molten metal is continuously provided at a lower end of the suction pipe.

[0005]

In order to pump out the molten metal by the molten metal pumping device according to the first aspect of the present invention, the tip of the suction pipe is immersed in the molten metal in the crucible, the atmosphere port is closed, and the vacuum port is closed. After opening, the vacuum pump is operated to discharge air from the inside of the tank, and the inside of the tank is reduced to a predetermined vacuum pressure set by a vacuum regulating valve. When the inside of the tank becomes a vacuum pressure, the molten metal in the crucible is sucked into the tank through the suction pipe due to a differential pressure between the atmospheric pressure acting on the molten metal in the crucible and the vacuum pressure of the tank. When the molten metal accumulates in the tank to a height corresponding to the differential pressure between the atmospheric pressure and the predetermined vacuum pressure set by the vacuum control valve, the suction from the crucible is automatically terminated. 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 drop from the tank. After the transfer of the tank, when the vacuum port is closed and the atmosphere port is opened, the inside of the tank is opened to the atmospheric pressure, and the molten metal is discharged from the tank to another container through the suction pipe.

According to the molten metal pumping device of the first aspect, since a movable member such as a piston and a rotor, which is indispensable for various types of pumps, is not required, the structure is extremely simple, low cost and high durability. It is possible to obtain a molten metal pumping means having a property. In particular, in the present invention, since the inside of the tank is adjusted to a predetermined vacuum pressure by providing a vacuum adjusting valve,
The amount of the molten metal sucked into the tank from the crucible can be appropriately maintained, and the airtightness of the tank during transfer can be prevented, so that the molten metal can be prevented from dripping from the suction pipe.

According to the second aspect of the present invention, since the sump is provided at the lower end of the suction pipe, when the suction pipe is separated from the molten metal of the container and the tank is transferred to another container, the sump is used for the sump. Molten metal accumulates, which can prevent air from entering the inside of the tank from the lower end opening of the suction pipe. When air enters the tank through the suction pipe during transfer of the tank, the vacuum pressure inside the tank decreases, the pressure difference between the inside and outside of the tank decreases, and the molten metal in the tank drops from the suction pipe. Since intrusion of air from the suction pipe can be prevented, dripping of molten metal can be reliably prevented in combination with the function of the vacuum control valve.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 apparatus 10 is for pumping molten aluminum 12 in a crucible 11 and has 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 opening of the iron case 15 is covered with an iron cover 17. It is configured.

A suction pipe 18 is provided at the bottom of the refractory container 14 and protrudes from the bottom 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 basin 19 for storing molten aluminum is attached to the screw thread.

As shown in FIGS. 2 and 3, the water reservoir 19 has a cylindrical structure having a bottom, in which a small-diameter hollow portion 20 and a large-diameter hollow portion 21 are formed. A screw thread 22 is formed on the inner peripheral surface of the small-diameter hollow portion.
Further, on the inner peripheral surface of the small-diameter hollow portion 20, four communication passages 23 each having a semicircular cross section are formed from the upper end opening of the small-diameter hollow portion 20 to the large-diameter hollow portion 21.

The iron lid 17 is provided with a vacuum port 25 connected to a vacuum pump 24 and an atmosphere port 26 communicating with the atmosphere, and opens and closes the ports 25 and 2 in pipes connected to the ports 25 and 26. On-off valves 27 and 28 are provided. A vacuum regulating valve 31 between the on-off valve 27 and the vacuum port 25;
Are arranged.

An O-ring 29 is interposed between the iron lid 17 and the iron case 15 to maintain airtightness. A mortar 30 having sealing properties is filled between the iron case 15 and the upper end of the refractory container 14 and between the iron case 15 and the bottom of the refractory container 14.

The molten metal pumping device 10 according to the present embodiment
Is as described above, and its operation will be described below. The sump 19 attached to the tip of the suction pipe 18 is placed in the crucible 11.
, The air port 26 is closed, the vacuum port 25 is opened, the vacuum pump 24 is operated to discharge air from the inside of the tank 13, and the inside of the tank 13 is set by the vacuum regulating valve 31. The pressure is reduced to a predetermined vacuum pressure.

When the pressure inside the tank 13 is reduced to a vacuum pressure, as shown in FIG. 4, the molten aluminum 12 in the crucible 11 is heated by a pressure difference between the atmospheric pressure acting on the molten aluminum 12 in the crucible 11 and the vacuum pressure in the tank 13. From the communication passage 23 of the reservoir 19 to the suction pipe 18
Is drawn into the refractory container 14 of the tank 13.
When the molten aluminum 12 accumulates in the refractory container 14 of the tank 13 to a height corresponding to the pressure difference between the atmospheric pressure and the predetermined vacuum pressure, the suction from the crucible 11 ends.

If the inside of the tank is temporarily set to a vacuum of Tricheno (−0.113 MPa) by the vacuum adjusting valve 31, mercury having a specific gravity of 13.5 g / cc is sucked up to a height of 76 cm. Therefore, molten aluminum 12 having a specific gravity of about 2.2 g / cc is about 466 cm (= 76 cm × 13.3 cm).
Suction to a height of 5 / 2.2). The height from the lower end of the suction pipe 18 to the upper end surface of the refractory container 14 is about 70 cm.
When set to, the pressure inside the tank is reduced to -0.0 by the vacuum adjustment valve.
015MPa (= -0.113MPa x 70cm / 4
If it is set to 66 cm), the overflow of the molten aluminum 12 from the refractory container 14 can be prevented.

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 as shown in FIG. The crucible 11 is separated from the molten aluminum 12 and the tank 13 is transferred to another container. Then, the vacuum ports 25 are closed and the atmospheric ports 26 are opened by operating the on-off valves 27 and 28. Then, the inside of the tank 13 is released to the atmospheric pressure, and the pressure difference between the inside and the 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.

The molten metal pumping device 10 according to the present embodiment.
According to the method, since a movable member such as a piston and a rotor, which is indispensable for various types of pumps, is not required, the structure is extremely simplified, and a low-cost and highly durable means for pumping molten aluminum can be obtained. . Further, since the vacuum adjusting valve 31 is provided to adjust the inside of the tank 13 to a predetermined vacuum pressure, the amount of the molten aluminum 12 sucked into the tank 13 from the crucible 11 can be kept constant, and the tank 13 can be moved during the transfer. Of the molten aluminum can be prevented from dropping from the suction pipe 18 due to a decrease in the airtightness.

Further, a water reservoir 19 is provided at the lower end of the suction pipe 18.
Is provided, when the suction tube 18 is separated from the molten aluminum in the crucible 11 and the tank 13 is transferred to another container, the molten aluminum is accumulated in the water sump 19, whereby the suction tube 18
Air can be prevented from entering the inside of the tank 13 through the lower end opening of the tank. When air enters the tank 13 through the suction pipe 18 during the transfer of the tank 13, the vacuum pressure in the tank 13 decreases, the pressure difference between the inside and outside of the tank 13 decreases, and the molten aluminum 12 in the tank 13 sucks. Although the water is dropped from the pipe 18, the intrusion of air can be prevented by the provision of the water pool 19, so that the vacuum adjustment valve 31 keeps the tank internal pressure at a predetermined vacuum pressure.
2 can be reliably prevented from dropping.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a molten metal pumping device according to an embodiment of the present invention.

FIG. 2 is a plan view of the water pool seen from line 2-2 in FIG.

FIG. 3 is a sectional view of the basin taken along line 3-3 in FIG. 2;

FIG. 4 is a sectional view showing an operation of the molten metal pumping device according to the embodiment of the present invention.

FIG. 5 is a sectional view illustrating the operation of the molten metal pumping device.

[Explanation of symbols]

10: molten metal pumping device, 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 regulating valve.

Claims (2)

[Claims] 1. A suction pipe of molten metal is vertically provided at the bottom of a tank, and a vacuum port connected to a vacuum pump and an atmosphere port communicating with the atmosphere are provided at the top of the tank, and an open / close valve for opening and closing each port is provided. A vacuum control valve is arranged between the vacuum pump and the vacuum port, the suction pipe is immersed in the molten metal, and the inside of the tank is set to a predetermined vacuum pressure set by the vacuum control valve to suck the molten metal into the tank. A molten metal pumping device wherein the tank is transferred while maintaining the inside of the tank at the predetermined vacuum pressure, and the inside of the tank is opened to the atmospheric pressure to discharge the molten metal in the tank from the suction pipe. 2. The molten metal pumping device according to claim 1, wherein a basin for storing the molten metal is connected to a lower end of the suction pipe.