JPH05180567A - Melting furnace for metal - Google Patents

Abstract

PURPOSE:To obtain a metal-melting furnace in which the feature of an electric furnace is employed to advantage and which enables scrap to be melted in smelting at a low cost. CONSTITUTION:A metal-melting furnace 1 is provided with a self-fluxing electrode 11 consisting of pressed scrap, that is, scrap shaped into a rod by pressing, and designed to preheat scrap 9 loaded on a water-cooled movable grate 8 by means of exhaust gas from the combustion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal melting furnace, in which a self-fluxing electrode obtained by press-molding scrap is melted and the electrode scrap itself is melted by arc heat of the metal melting furnace to obtain a metal melt. Regarding

[0002]

The electrolysis of scrap is generally carried out by utilizing the heat of an arc generated from the tip of a graphite electrode, but the consumption of the graphite electrode occupies a large part of the production cost. There is. The properties required for the electrode are that it is a good conductor of electricity and difficult to oxidize, it does not cause chemical reaction with the charge in the furnace and does not harm the molten metal. The price is required to be low. The electrode currently used in general electric furnaces to meet these requirements is a graphite electrode, but its consumption is large (4-5
kg / t), which is a major factor in increasing the manufacturing cost.

The present invention has been made in view of the above problems of the prior art, and its purpose is to make use of the features of an electric furnace and to make a metal capable of melting and refining scrap at low cost. To provide a melting furnace.

[0004]

In order to achieve the above object, the gist of the present invention is to provide a self-melting electrode in which a scrap is pressed into a rod shape as an electrode in a metal melting furnace that melts scrap using electric energy as a main heat source. Hereinafter, the metal melting furnace is characterized in that it has a "pressed scrap electrode").

[0005]

[Operation] When electricity is applied to the pressed scrap electrode of the metal melting furnace, an arc is generated at the tip of the electrode, and the heat of the metal melts the charging scrap and gradually melts the electrode itself from the tip to continuously produce molten metal. Obtainable.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a metal melting furnace according to the present invention.
In the figure, 1 is a metal melting furnace in which a refractory brick 2 is stretched on the inner surface, and a tap 4 for discharging a metal melt 3 on the furnace side wall.
Further, a slag port 6 for discharging the slag 5 is provided, and an exhaust gas duct 7 is further provided at the furnace top opening, and a scrap 9 is dammed in the exhaust gas duct 7 by a water cooling movable grid 8. Scrap 9 is hot from the furnace (1000
When heated to a certain temperature, the water-cooled movable grid 8 opens and the preheated scrap 9 can be fed into the furnace. The scrap is replenished by opening the movable lid 10. Reference numeral 11 denotes a pressed scrap electrode, which is energized by a direct current method in this embodiment, and therefore has one electrode 11a (hereinafter referred to as "furnace bottom electrode") at the furnace bottom. The bottom electrode is the same as that used in a general DC electric furnace. Reference numeral 12 is an electrode holder that holds an electrode and moves up and down, and 13 is a chute into which a slag material is loaded. The furnace wall is water-cooled in order to suppress the consumption of refractory materials.

Next, the scrap melting and refining process of the metal melting furnace according to the present invention will be described with reference to the drawings.

Pressed scrap electrode 11, furnace bottom electrode 1
By energizing 1a, an arc is generated between the electrode tips or between the charging scrap and the charging scrap is melted, and the pressed scrap electrode 11 itself is gradually melted from the tip to form a metal melt 3. To be done. When the pressed scrap electrode 11 is consumed by a certain amount, a new pressed scrap electrode is joined to the upper end of the pressed scrap electrode 11 to continue its function as an electrode. The molten metal 3 and the slag 5 accumulated in the furnace are bored with a hole punching machine (not shown) at a tap hole 4 or a slag hole 6 which is filled with refractory material in advance with a mud gun (not shown). As a result, it is discharged outside the furnace. With melting, a large amount of high-temperature gas is generated from the inside of the furnace, but the scrap 9 on the water-cooled movable grid 8 is heated by this exhaust gas, and when the temperature of this scrap reaches a constant temperature (for example, about 400 ° C.), The water-cooled movable grid 8 is opened, and the preheated scrap falls into the furnace.

Since the above embodiment is of the DC type, the number of pressed scrap electrodes 11 is one, but in the case of the three-phase AC method, three pressed scrap electrodes may be charged into the furnace.

[0010]

Since the present invention is configured as described above, it has the following effects. Since the molten metal is obtained by using a self-fluxing type electrode that also serves as a metal raw material and an electrode material, no electrode cost is required, and scrap can be continuously melt-refined at an extremely low cost.

Further, the combined use of the pressed scrap electrode of the present invention and the scrap preheating by exhaust gas can be used to further improve the thermal efficiency.

[Brief description of drawings]

FIG. 1 is a sectional view of a metal melting furnace of the present invention.

[Explanation of symbols]

 1 ... Metal melting furnace 3 ... Metal melt 5 ... Slag 7 ... Exhaust gas duct 9 ... Scrap 11 ... Pressed scrap electrode

Claims (1)

[Claims] 1. A metal melting furnace for melting scrap using electric energy as a main heat source, wherein the metal melting furnace has a self-fluxing electrode formed by press-molding scrap as an electrode.