JPH01219495A - Furnace bottom discharge method for melting furnace and device thereof - Google Patents

Abstract

PURPOSE:To enable prevention of the stop of discharge of a molten metal in the middle of discharge, by a method wherein a molten metal is cooled for solidification, a tap hole is closed, after completion of a melting and refining process, a metal solidified in the tap hole is heated and molten, and a stopper is elevatably mounted to the upper opening part of the tap hole. CONSTITUTION:When, after a tap hole 24 is close and melting and refining are completed, a high frequency current is fed through a transmission line 36 to a coil 27, the coil 27 generates heat, and a metallic lump solidified in the tap hole 24 is molten, the tap hole 24 is opened, and a molten metal contained in a furnace is discharged through the tap hole 24. When, during discharge of the molten metal, the feed of the molten metal is stopped, a stopper 32 is lowered in the molten metal to close the upper part of the tap hole 24, and through closing of an openable gate 28, the lower part of the tap hole 24 is closed. By cooling the molten metal confined in the tap hole 24 by the feed of cooling water to the interior of the hollow coil 27, the molten metal is solidified in the tap hole 24 again, and the tap hole 24 is closed again to stop discharge.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for discharging the bottom of a melting furnace and a bottom discharging device thereof, and particularly relates to a bottom discharging method for a melting furnace in which the spout is not filled with sand. The present invention relates to a method and a bottom discharge device thereof.

[Conventional technology] Metal melting furnaces are generally used to melt and melt scrap.
Arc furnaces for refining, converters for refining hot metal tapped in blast furnaces, and the like are known.

In recent years, a bottom tapping type arc furnace 5 as shown in FIG. 3 has been adopted. As shown in the figure, the bottom tapping type arc furnace 5 has a furnace body 2 and a furnace lid 3 made of steel plates and refractory bricks, and a part of a spherical furnace bottom 6 extending radially outward. A tapping section 7 is provided by letting the steel tap out, and a tap hole 8 is formed in this tapping section 7. Insert this from below to this hot water outlet 8.
An opening/closing gate 9 is installed, and a gate 9 is installed directly below it.
A10 is now installed.

This bottom tapping type arc furnace 5 requires only a small inclination angle of the furnace body 2 due to the tilting device 11 provided on the furnace body 2, and since the steel is tapped from the furnace bottom 6, slag does not get mixed into the tapped steel 11. It's difficult.

The opening/closing gate 9 that closes the outlet 8 employs a flapper gate 12 that rotates as shown in FIG. 4 and a slide gate 13 that moves horizontally as shown in FIG. 5.

The structure of this outlet 8 was to form a cylindrical n-hole through the steel plate and refractory bricks of the hearth bottom 6, and a graphite block 14 was placed inside the inner wall of the hole.

The tap 8 was closed by filling the tap 8 with sand 15 from inside the furnace after closing the V8 closing gate 9.

The bottom tap type arc furnace 5 with the hot water tap 8 opened in this way
When tapping the steel, sand 15 was removed from below the water outlet 8 and molten steel was discharged, as if the rM opening/closing gate was opened.

[Problems to be Solved by the Invention] By the way, in the bottom tapping of conventional melting furnaces, there are the following problems.

After filling the sand 15 in the hot water outlet 8, melting is performed,
Since the melter was discharging this and tapping the molten steel stored in the furnace, the sand 15 was discharged from the spout 8 and the sand 15 was discharged from the tap 8 until the tapping was completed. There was a problem in that it remained open and it was impossible to stop the discharge of molten steel midway.

Therefore, slag cutting and operation with remaining hot metal in the furnace have been carried out by tilting the furnace body and varying the hot water level.

However, in converters and the like, due to the structure of the furnace body, it is not possible to leave residual metal even if the furnace is tilted in this manner.

In view of the above-mentioned problems, the present invention provides a method for discharging a melting furnace that does not require filling with sand (opening the spout and stopping discharging molten metal during discharging), and a discharging method thereof. The purpose of this invention is to provide a furnace bottom discharge device.

[Means for solving the vR problem] In order to achieve the above object, the method for discharging the bottom of a melting furnace of the present invention includes closing the upper and lower parts of the spout to seal molten metal therein, This molten metal is cooled and solidified, and the spout is opened. After the melting and refining process is completed, the solidified metal in the spout is heated and melted, and the molten metal stored in the furnace is discharged. This is what I did.

Moreover, the furnace bottom discharge 5A position of the melting furnace of the present invention includes an opening/closing gate that closes the lower opening of the tap hole formed in the furnace bottom;
a stopper that faces the upper opening of the gushing port and is movable up and down to close it; a hollow coil that is spirally provided along the inner wall of the gushing port; and a hollow coil that is connected to the coil; energizing means for passing a high-frequency Wi current through it;
A water supply means is connected to the coil and supplies cooling water into the coil.

[Function] The furnace bottom discharge method according to claim 1 is performed using the apparatus according to claim 2. First, the lower opening of the tap hole formed at the bottom of the furnace is closed with an opening/closing gate, and the metal is melted inside the furnace. Next, a stopper is lowered into the furnace to close the upper opening of the lift port. When the upper and lower parts of the evacuation port are closed, molten metal is sealed inside. The molten metal sealed in the spout is cooled and solidified by supplying cooling water from the water supply means into the hollow coil spirally provided along the inner wall of the spout. As the molten metal solidifies inside the spout, the spout is closed. After completing the melting and refining process in the furnace, a high frequency current is passed through the coil from the current supply means to melt the solidified metal in the discharge port. As a result, the spout is studded, and when the opening/closing gate is released, the molten metal contained in the furnace is discharged.

Also, when you want to stop discharging molten metal during discharging,
The molten metal being discharged is sealed in the spout by the opening/closing gate and the stopper, and water is supplied from the water supply means into the hollow coil, so that the molten metal solidifies in the spout again and the spout is closed. The discharge shall be stopped.

[Example] Examples of the method for discharging the bottom of a melting furnace and the apparatus for discharging the bottom of a melting furnace according to the present invention will be described below in detail with reference to the accompanying drawings.

First, a bottom discharge device for a melting furnace according to the present invention will be explained. As shown in FIG. 1, the furnace body of the melting furnace 20 is formed of a steel plate 21 and refractory bricks 22. FIG. 1 shows the main part of the furnace bottom 23, and the furnace bottom 23 is formed with a drain port 24 for discharging the molten metal contained in the furnace.

This hot water outlet 24 is connected to the steel plate 21 and the refractory brick 22.
A graphite block 26 is placed inside a through hole 25 which is opened in a cylindrical shape. Inside this graphite block 26 or the fireproof brick outside it, there is a hot water outlet 2.
A hollow coil 27 spirally extends in the circumferential direction along the inner wall of 4.
is built-in. This hollow coil 27 is made of a material with good thermal and electrical conductivity, such as a steel pipe, and both ends thereof are exposed at the lower end of the spout 24 that protrudes downward from the furnace bottom 23. .

In addition, at the bottom of the hot water outlet 24, the lower opening is Il.
An open gate 28 is provided.

FIG. 1 shows a flapper gate 2 as this opening/closing gate 28.
Figure 2 shows the slide gate 30.
was adopted. This opening/closing gate 28 can be opened by operating the opening/closing handle 31 as shown in FIG.
It has a mechanism that can be closed, and is equipped with a hydraulic cylinder and a drive motor shade.

Further, a stopper 32 is provided at the bottom of the melting furnace 20 so as to be movable up and down so as to close the upper opening of the spout 24. This stopper 32 is made of a round bar having a cross-sectional area 4j larger than the opening portion of the drooping hole 240, and is made of a heat-resistant material such as graphite. As shown in FIG. 2, this stopper 32 is raised and lowered by, for example, a lift 1II8ffi33 such as a hydraulic cylinder.

Furthermore, a current supply means 34 is connected to the hollow coil 27 for passing a high frequency current therethrough.

The current supply means 34 includes a high frequency power source 35 and a power transmission line 36 for transferring the high frequency current generated from the high frequency power source 35 to the coil 27.

Further, a water supply means 37 is connected to the hollow coil 27, with one of the exposed ends serving as an inlet and the other end serving as an outlet, for supplying water to the interior thereof. This water supply means 37 includes a water tank 38 for storing water, and this tank 3.
Water supply pipe 3 connected from 8 to the inlet side of the coil 27
9, a pump 40 interposed in the water supply pipe 39, and a water discharge pipe 41 connected to the tank 38 from the outlet side of the coil 27.

Next, a method for discharging the bottom of a melting furnace according to the present invention will be described by employing the bottom discharging device 42 for a melting furnace according to the present invention as shown in FIGS. 1 and 2.

First, the tap hole 24 formed in the bottom 23 of the melting furnace 20
The lower opening is closed with an opening/closing gate 28. This opening/closing gate 28 is operated by operating the IWUm handle 31, for example. Then, scraps and the like are put into the furnace and melted. In a converter, hot metal is injected. Next, the stopper 32 is lowered into the furnace by a lifting device 133 such as a hydraulic cylinder. This stopper 32 is made of a heat-resistant material such as graphite. And this stopper 32
The upper opening of the hot water outlet 24 is closed.

As a result, the molten metal is confined within the exhaust port 24. Thereafter, the pump 40 of the water supply means 37 is operated to supply water from the water tank 38 to the hollow coil 27 via the water supply pipe 39.
Supply cooling water inside. This hollow coil 27 is installed inside the graphite block 26 installed in the spout 24 in the circumferential direction along the inner wall of the spout 24, so that the molten metal sealed inside the spout 24 can be transferred to the outer periphery. It will be cooled down from. The cooled molten metal solidifies and exits from the tap 24.
A cylindrical metal lump is formed inside, and the hot water outlet 24 is 111
It will be plugged. At this time, the stopper 32 is lifted out of the furnace by the lifting device 33.

The cold 7J water passed through the coil 27 is the water drain pipe 4
1 and then returned to the water tank 28 for circulation.

In this manner, the leakage port 24 is closed and the melting/refining process is completed, and a frequency current is supplied to the coil 27 from the high frequency power source 35 of the current supply means 34 via the power transmission line 36.

Then, the coil 27 generates heat, and the metal lump solidified in the spout 24 is heated and melted, and the spout 24 is opened, and a drawer (not shown) is positioned directly below the spout 24. Then, when the opening/closing gate 28 is opened by the opening/closing handle 31 or the like, the molten metal contained in the furnace is discharged from the exhaust port 24.

When discharging the molten metal while it is being discharged, the stopper 32 is lowered in the molten metal by the lifting device 33 to close the upper part of the spout 24 and the opening/closing handle 31 of the opening/closing gate 28 is closed. etc., to close the lower part of the drainage port 24. Then, if the molten metal sealed in the hot water outlet 24 is cooled by supplying cold water into the hollow coil 27 by the water supply means 37, the molten metal will solidify in the hot water outlet 24 again, and the molten metal will be poured out. Mouth 24G
cL will be opened and discharge will be stopped.

As described above, according to the present invention, the spout 24 can be opened without using sand, and furthermore, the discharge of molten metal can be freely stopped during discharge. Therefore, residual molten metal can be obtained in the furnace without tilting the furnace body, and especially when adopted in a converter or the like, it is possible to perform scrap mixing and melting.

[Effects of the Invention] In summary, according to claims 1 and 2 of the present invention,
The molten metal contained in the furnace can be freely discharged and stopped. This allows residual metal to remain in the furnace,
The residual metal can be used for high scrap melting, especially in converters.

Furthermore, sand as a filler and a device for filling it are no longer required.

Furthermore, since molten steel can be freely discharged and stopped during tapping, the degree of freedom in operations such as small-lot production can be expanded.

[Brief explanation of the drawing]

FIG. 1 is a schematic view of the main parts of a first embodiment of a bottom discharge device for a melting furnace according to the present invention, and FIG. 2 is a schematic diagram showing a second embodiment of a bottom discharge device for a melting furnace according to the present invention. 3 are schematic diagrams showing a bottom tapping type arc furnace, and FIGS. 4 and 5 are schematic diagrams showing main parts of a conventional structure. In the figure, 20 is a melting furnace, 23 is a furnace bottom, 24 is a spout, 2
7 is a hollow coil, 28 is an opening/closing gate, 34 is an energizing means,
37 is a water supply means.

Claims (1)

[Claims] 1. When the upper and lower parts of the spout are closed to cool and solidify the molten metal inside the spout, and the molten metal is discharged, the molten metal is solidified inside the spout. A method for discharging the bottom of a melting furnace, characterized by heating and melting molten metal and discharging the molten metal contained in the furnace. 2. An opening/closing gate that closes the lower opening of the spout formed in the bottom of the furnace, a stopper that faces the upper opening of the spout and is movable up and down to close it, and the spout. A hollow coil spirally provided along the inner wall of the
1. A bottom discharge device for a melting furnace, comprising: an energizing means connected to the coil for passing a current through the coil; and a water supply means connected to the coil for supplying water into the coil.