JPH06194055A - Crucible type furnace - Google Patents

Abstract

PURPOSE:To prevent a melt quality from being deteriorated by bringing combustion waste gas into contact with a melt surface in the course of keeping the melt by rotating a hollow arm around a flue to cause a material preheating cylinder to go back from the upper portion of a furnace cover, and providing a blind cover on the upper surface of the furnace cover, and further opening an opening/closing cover of the flue to exhaust combustion gas from the upper end of the flue to the outside. CONSTITUTION:A furnace cover 5 having a material introduction inlet 4 is disposed freely to open and close on the upper surface of a furnace 2, and combustion waste gas is exhausted from a flue 6 provided on a side wall of the furnace 2 by bringing the lower surface of the furnace cover 5 into close contact with the upper edge of the crucible 1 in the state of the furnace cover 5 being disposed. A material preheating cylinder 7 is placed around the material introduction inlet 4 in the upper surface of the furnace cover 5, and a cylinder 8 rotatable around an axis of the flue 6 is fitted over the upper external peripheral surface of the flue 6. Further, the side wall of the material preheating cylinder 7 and the side wall of the cylinder 8 are coupled and fixed through a hollow arm 9 to permit the material preheating cylinder 7 to be rotatable around the flue 6. Further, a vent hole 10 provided through the side wall of the flue 7 and the material preheating cylinder 7 are communicated with each other through the hollow arm 9 to form a communication flue from the flue 6 to the material preheating cylinder 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crucible furnace used for melting and holding aluminum and the like.

[0002]

2. Description of the Related Art FIG. 5 shows a crucible furnace which has been conventionally used for a melting furnace of an aluminum casting machine. The crucible 1 is housed in a vertical furnace 2 having a burner 3 at the bottom thereof. Insert the ingot material 14 from the material inlet 4 provided in the furnace lid 5,
It is melted and held in the crucible 1, and is widely used as a hand holding furnace because of its simple structure and relatively low cost.

[0003]

However, in the above crucible furnace, as shown by the arrow in FIG. 5, the combustion exhaust gas from the burner 3 heats the peripheral wall of the crucible 1 and then the upper edge of the crucible 1 and the furnace. Since the material was discharged from the material inlet 4 through the gap of the lid 5, after the ingot material was melted, the exhaust gas touched the surface of the molten metal to oxidize the molten metal, or the exhaust gas was melted in the molten metal and the purity of the molten metal was increased. There was a problem that it lowered. In view of the above problems, the present invention aims to provide a crucible furnace capable of sufficiently preheating the ingot material during melting of the ingot and separating the exhaust gas and the molten metal from each other while maintaining the molten metal. It is what

[0004]

As shown in FIGS. 1 and 2, a crucible furnace according to the present invention is provided with a burner 3 in the lower part of a furnace 2 accommodating a vertical crucible 1, and a burner 3 exhausts combustion gas. In a crucible furnace configured to heat the crucible 1, the lower surface of the furnace lid 5 having the material inlet 4 and the upper edge of the crucible 1 are brought into close contact with each other, and the flue gas 6 connected to the side wall of the furnace 2 The side wall of the material preheating cylinder 7 placed on the upper surface of the furnace lid 5,
By connecting the side wall of the cylindrical body 8 rotatably fitted to the upper outer peripheral surface of the flue 6 with the hollow arm 9, the material preheating cylinder 7
Is rotatable around the flue 6, and the hollow arm 9 allows the vent hole 10 provided on the side wall of the flue 6 to communicate with the material preheating cylinder 7. Further, the open / close lid 11 is provided on the upper end of the flue 6. And a lid plate 13 having an exhaust port 12 in the material preheating cylinder 7
Is provided so that it can be detached.

[0005]

In use, as shown in FIG. 3, the hollow arm 9 is first rotated to install the furnace lid 5 having the material preheating cylinder 7 on the furnace 2, and the upper end opening of the material preheating cylinder 7 is opened. Ingot material 14
Then, the cover plate 13 is attached. In this state,
The flue 6 and the material preheating cylinder 7 communicate with each other. When the opening / closing lid 11 at the upper end of the flue 6 is closed, the combustion exhaust gas from the burner 3 heats the crucible 1 and then the flue 6 and the hollow arm 9 are closed. After passing through the material preheating cylinder 7 to preheat the material, the exhaust port 12
Emitted from. When the ingot material is melted, the molten metal is entirely contained in the crucible 1. Therefore, as shown in FIG. 4, the hollow arm 9 is rotated around the flue 6 to move the material preheating cylinder 7
Is evacuated from the top of the furnace lid 5, and instead a blind lid 15 is provided on the upper surface of the furnace lid 5, and the open / close lid 11 of the flue 6 is opened to discharge combustion exhaust gas from the upper end of the flue 6 to the outside. Let
Therefore, according to this configuration, the exhaust gas is used for preheating the material at the time of melting, and the exhaust gas is discharged from the flue 6 after melting,
It is possible to prevent contact between the exhaust gas and the molten metal.

[0006]

1 and 2 show an embodiment of a crucible furnace according to the present invention, in which a burner 3 is provided below a furnace 2 in which a vertical crucible 1 is housed, and the burner 3 burns. The crucible 1 is heated by the exhaust gas, and a furnace lid 5 having a material inlet 4 is openably and closably attached to the upper surface of the furnace 2. In the state where the furnace lid is attached, the lower surface of the furnace lid 5 and the upper edge of the crucible 1 are in close contact with each other, so that the combustion exhaust gas flows from the flue 6 connected to the side wall of the furnace 2. Is discharged. On the upper surface of the furnace lid 5, a material preheating cylinder 7 is placed around the material inlet 4, while on the outer peripheral surface of the upper part of the flue 6, a cylindrical body 8 rotatable around the flue 6 is fitted. By being inserted and the side wall of the material preheating cylinder 7 and the side wall of the cylindrical body 8 are connected and fixed by the hollow arm 9, the material preheating cylinder 7 can be rotated around the flue 6. Further, the hollow arm 9 communicates the ventilation hole 10 provided on the side wall of the flue 6 with the material preheating tube 7 to form a communication flue from the flue 6 to the material preheating tube 7. An open / close lid 11 is provided on the upper end of the flue 6, and a lid plate 13 having an exhaust port 12 is detachably attached to the material preheating cylinder 7.

FIG. 3 shows the state during melting, and the furnace 2
The material preheating cylinder 7 is placed on the furnace lid 5 provided on the upper surface of the above, and the open / close lid 11 at the upper end of the flue 6 is closed. In this state, when the ingot material 14 is charged from the upper end opening of the material preheating cylinder 7 and the lid plate 13 is attached to the upper surface of the material preheating cylinder 7,
The combustion exhaust gas from the burner 3 heats the crucible 1 and then enters the material preheating cylinder 7 through the flue 6 and the hollow arm 9 as shown by the arrow, preheats the material, and then is discharged from the exhaust port 12. . The hollow arm 9 is obliquely connected so that the exhaust gas blows toward the tangential direction of the material preheating cylinder 7 as shown by the arrow in FIG. 2, so that the exhaust gas is inside the material preheating cylinder 7 and in the crucible. Ingot material 1 circulated in 1
4 is sufficiently preheated and then discharged from the exhaust port 12. In FIG. 3, 15 is an annular bearing, 16 is a metal fitting, and 17 in FIG. 2 is a reinforcing material.

FIG. 4 shows a state during holding. When the ingot material 14 is completely melted, the molten metal is contained in the crucible 1, so that the hollow arm 9 is rotated about 90 degrees around the flue 6. By moving the material preheating cylinder 7 away from the furnace lid 5,
Instead, a blind lid 18 is provided on the upper surface of the furnace lid 5, and the open / close lid 11 of the flue 6 is opened to discharge the combustion exhaust gas from the upper end of the flue 6 to the outside. At this time, the vent hole 10 on the side wall of the flue 6 is closed by the side wall of the tubular body 8. In this way, the contact between the exhaust gas and the molten metal is completely cut off, and the molten metal is prevented from being oxidized or discolored. However, the blind lid 18 is not always necessary to achieve the object of the present invention. When an exhaust duct is connected to the upper end of the flue 6, a damper may be used as the opening / closing lid 11.

[0009]

According to the present invention, as described above, the combustion exhaust gas in the furnace is once guided to the flue 6 and is melted when the material is preheated.
By blowing from the side of, the material can be efficiently refluxed to preheat the material, and after melting, the exhaust gas can be discharged from the upper end of the flue 6 to prevent contact between the exhaust gas and the molten metal. There is an advantage that the quality of the molten metal can be improved and the working environment at the time of pumping can be improved by separating the molten metal and the exhaust gas.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention.

FIG. 2 is a top view of the above.

FIG. 3 is a vertical cross-sectional view showing a state of the above-mentioned melting.

FIG. 4 is a vertical cross-sectional view showing the state of holding the same as above.

FIG. 5 is a vertical sectional view of a conventional example.

[Explanation of symbols]

 1 Crucible 2 Furnace 3 Burner 4 Material Inlet 5 Furnace Lid 6 Flue 7 Material Preheating Tubing 8 Tubular Body 9 Hollow Arm 10 Vent 11 Opening / Covering 12 Exhaust 13 Blind 14 Ingot 15 Bearing 16 Locking 17 Reinforcing Material

Claims (1)

[Claims] 1. A crucible furnace in which a burner is provided in a lower portion of a furnace containing a vertical crucible so that the combustion exhaust gas of the burner heats the crucible. In the crucible furnace, a lower surface of a furnace lid having a material inlet and a crucible above. Guide the flue gas to the flue connected to the side wall of the furnace by making close contact with the edge, and rotatably fit to the side wall of the material preheating cylinder placed on the upper surface of the furnace lid and the outer peripheral surface of the upper part of the flue. By connecting the side wall of the inserted tubular body with a hollow arm, the material preheating tube can be freely rotated around the flue, and the ventilation hole provided on the side wall of the flue and the material preheating tube can be rotated by the hollow arm. A crucible furnace in which the lids are made to communicate with each other, an opening / closing lid is provided on the upper end of the flue, and a lid plate having an exhaust port is detachably attached to the material preheating cylinder.