JPS647314B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Hereinafter, fields of application, prior art, and other objects of the invention) The present invention relates to a nonferrous metal molten metal holding device. Conventionally, crucible-type melting and holding furnaces such as graphite crucibles or iron crucibles for nonferrous metals such as aluminum, zinc, and their alloys are generally of an external indirect heating type using heavy oil, gas, or the like as a heat source. However, from the perspective of reducing fuel costs and improving quality,
Instead of these crucibles, holding furnaces using electricity as a heating source have come to be used (for example, the
Publication No. 38342). In this case, it is not possible to use a so-called external heating method in which the furnace is heated from outside the furnace. Therefore, two methods are used to heat the molten metal: indirect heating from the surface of the molten metal, and direct heating in which an electric heater is immersed in the molten metal. However, in the case of indirect heating, when the molten metal is pumped out, the molten metal may come into contact with an electric heater installed on the ceiling away from the surface of the molten metal, or when the material is put in, it may come into contact with the electric heater. There is a problem that oxides (ghosts) that have grown on the furnace wall come into contact with the electric heater and shoot out, damaging the electric heater and causing sudden accidents that make the electric heater unusable. Since the terminals of the electric heater must be outside the furnace,
It is necessary to sufficiently seal the space between the electric heater and the furnace wall to prevent molten metal from leaking. The reality is that it is difficult to complete this seal and the sealing operation cannot be performed quickly.
In any case, heating with an electric heater cannot apply a sudden heat load compared to heating with external heating type heavy oil or gas. Therefore, when handling a large amount of molten metal or when raising the temperature in a short time, it is necessary to increase the number of electric heaters in one furnace. As the number of electric heaters increases, the amount of labor and expense spent on the electric heaters increases accordingly. The present invention uses a direct heating type in which a gas-fueled radiant heating element is charged into the molten metal and a unique furnace structure, thereby eliminating the above-mentioned conventional drawbacks, improving quality, and improving the quality of the furnace. This is intended to simplify cleaning.

(Structure and operation of the invention hereinafter) Reference numeral 1 denotes a radiant tube type heating element, and this radiant tube type heating element 1 has the following configuration. That is, a flame stabilizing section 3 is formed on one side of the inner tube 2, and the combustion gas returns through the outer tube 4 provided outside the inner tube 2 to the vicinity of the flame stabilizing section 3, that is, the exhaust heat recovery section 5. It exchanges heat with combustion air and discharges it outside. Reference numeral 6 denotes a furnace body, which has a bottom portion 7 formed in a substantially V-shape and is provided with an inclined portion 14 toward the outlet 17. The heating element 1 is inserted into the furnace so that it reaches the vicinity of the bottom part 7 of the furnace. Fireproof partition walls 8 are constructed on both sides of the charged heating element 1,
The fireproof partition wall 8 constitutes a pouring chamber 9, a heating chamber 10, and a pumping chamber 11.
are configured to communicate with each other at their lower parts. The furnace body shape shown in FIGS. 1 and 2 is an example in consideration of the internal volume of the furnace, but it is not limited to the example shown, and may have any configuration as long as the furnace bottom 7 has a substantially V-shape. But that's fine. Thus, the gas introduced from the gas introduction part 12 and the air introduced from the air introduction part 13 are partially mixed in the flame holding part 3 and combusted in the inner tube 2 while holding the flame. sustain. Combustion gas flows partially through the small hole 15 provided in the inner tube 2 to the outer tube 4.
Most of the heat flows out from the tip of the inner tube 2 into the outer tube 4 and returns to the exhaust heat recovery section 5.
It exchanges heat with the combustion air introduced from the air introduction part 13 and is discharged. In the flow of combustion gas, the combustion heat is transferred to the outer tube 4 and heats the molten metal 16. The outer tube 4 is preferably made of a material that has no reactivity with the molten metal 16 and is durable, such as silicon carbide. things are suitable. It is desirable that the heating element 1 is constructed so that it can be moved within the furnace and replaced.

(Effects of the Invention Below) Since the present invention is as described above, it has the following advantages. Since it uses the above-mentioned radiant tube type heating element, it is capable of high-load combustion, has a large temperature-raising capacity, has high thermal efficiency, and can heat a large amount of molten metal in a short time, providing outstanding workability. Excellent. Therefore, the number of heating elements installed in the furnace can be extremely reduced. Since the above-mentioned radiant tube type heating element is used, there is an advantage that the heating element can be replaced as if replacing a single rod, and there is no fear of leakage of molten metal as with electric heaters. Since combustion energy is used effectively, it is much more energy efficient than electric energy. Since the heating element 1 is configured to reach the vicinity of the approximately V-shaped furnace bottom 7,
The immersed portion of the charged heating element 1 becomes larger relative to the amount of molten metal, and the heating efficiency improves accordingly. Heavy metals in the molten metal will fall into the furnace bottom 7,
Heavy metals are not mixed into the molten metal pumped out from the pumping chamber 11, which is very beneficial for improving and stabilizing quality. Since the heating element 1 in the heating chamber 10 has partition walls 8 on both sides, it is protected from impact when pouring metal into the pouring chamber 9, and impurities that easily float such as oxides are removed from the heating chamber. 10 and pumping room 11
Therefore, the molten metal that is pumped out is purified molten metal, which has the advantage of further improving the quality. Since the furnace bottom 7 has a substantially V-shaped configuration, the molten metal can be pumped out from the pumping chamber 11 without waste until the remaining amount becomes small. Since the furnace bottom part 7 has an inclined part 14 facing toward the outlet 17, the remaining amount is reduced as described above, and cleaning is easy.

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are cross-sectional explanatory views showing embodiments of the present invention. Code 1...Radiant tube heating body, 2...Inner tube, 3...Flame holding part, 4
...Outer tube, 5...Exhaust heat recovery section, 6...Furnace body, 7...
...Furnace bottom, 8...Refractory partition wall, 9...Pouring chamber, 1
0... Heating chamber, 11... Pumping chamber, 12... Gas introduction part, 13... Air introduction part, 14... Inclined part. 1
5...small hole, 16...molten metal, 17...exit.

Claims (1)

[Scope of Claims] 1. A flame-holding section is formed on one side of the inner tube, and the combustion gas returns through the outer tube provided outside the inner tube and exchanges heat with combustion air near the front flame-holding section. A radiant tube type heating element, which is discharged outside, is inserted into a furnace with a roughly V-shaped furnace bottom up to the vicinity of the V-shaped furnace bottom, and fireproof partition walls are provided on both sides of the heating element. A non-ferrous metal molten metal holding device comprising: a pouring chamber, a heating chamber, and a pumping chamber formed by the fireproof partition wall, each chamber communicating with the other at a lower portion thereof. 2 A flame-holding section is formed on one side of the inner tube, and the combustion gas returns through the outer tube provided outside the inner tube, exchanges heat with combustion air near the front flame-holding section, and is discharged to the outside. A radiant tube type heating element is charged to the vicinity of the V-shaped furnace bottom in a furnace having a substantially V-shaped furnace bottom and an inclined portion toward the exit direction,
Fireproof partition walls are formed on both sides of the heating body, and the fireproof partition walls form a pouring chamber, a heating chamber, and a pumping chamber, and each chamber communicates with the non-ferrous metal at its lower part. Molten metal holding device.