JPH0548070Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a bottom discharge device for a melting furnace, and more particularly to a discharge mechanism for sand filled in a spout.

[Prior Art] Generally known metal melting furnaces include arc furnaces, which mainly melt and refine scrap, and converters, which refine hot metal tapped in blast furnaces.

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. The tapping section 7 is provided by letting it come out,
A tap hole 8 is formed in this tapped portion 7. This hot water outlet 8 is provided with an opening/closing gate 9 that closes it from below, and a ladle 10 is placed directly below the opening/closing gate 9.
is being installed. This bottom tapping type arc furnace 5 has a tilting device 11 provided in the furnace body 2.
The angle of inclination of the furnace body 2 is also small, and since the steel is tapped from the bottom 6 of the furnace, slag is less likely to get mixed into the ladle 11.

The opening/closing gate 9 that closes the hot water outlet 8 includes:
Rotating flapper gate 1 as shown in Fig. 4
2 and a horizontally movable slide gate 13 as shown in FIG.

The structure of the hot water outlet 8 was such that a cylindrical through hole was formed through the steel plate and refractory bricks of the hearth bottom 6, and a graphite block 14 was placed inside the hole.

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

To tap the steel from the bottom tapping type arc furnace 5 with the tap 8 closed, the sand 15 is removed from below the tap 8 and the molten steel is discharged after opening the opening/closing gate 9. Ta.

[Problem to be solved by the invention] By the way, in the case of the conventional bottom discharge device of a melting furnace, the removal of the sand 15 filled into the spout 8 to close it is simply a natural fall of the sand 15 due to its own weight. If a drop failure occurred due to clogging of the sand 15 or baking in a high-temperature part, the sand 15 was removed by artificially poking it from the bottom or by blowing in _O2 . In this case, there was a problem that the melt was suddenly discharged and scattered, which was dangerous.

In view of the above-mentioned problems, the present invention is designed to easily remove sand that has become loose due to baking etc. from the spout.
Another object of the present invention is to provide a bottom discharge device for a melting furnace that can be safely removed.

[Means for Solving the Problems] In order to achieve the above object, the present invention is to fill the spout formed at the bottom of the melting furnace with sand, melt and refine it, and discharge the sand into the furnace. In the bottom discharge device of a melting furnace for discharging molten material, the inner wall of the spout and the inner wall of the opening/closing gate that closes the lower opening of the spout face the sand filled in the spout. A blow-off nozzle for blowing out inert gas or air is provided, and a gas supply means is provided for supplying the inert gas or air to the nozzle in synchronization with the opening operation of the opening/closing gate.

[Function] It is constructed as described above, and the blowing nozzle is provided on the inner wall of the hot water spout and the inner wall of the opening/closing gate. This blow-off nozzle faces the sand filled in the spout, and is equipped with a gas supply means. This gas supply means is adapted to supply inert gas or air to the blow-off nozzle in synchronization with the opening of the opening/closing gate. Therefore, when the opening/closing gate is opened, inert gas or air is blown into the sand from the blowing nozzle, and the blowing pressure removes the sand stuck in the spout due to baking or the like.

Furthermore, when an inert gas is used, it does not have any adverse effects such as oxidation on the melt discharged from the spout.

[Example] An example of the bottom tapping device for a melting furnace of the present invention will be described below in detail with reference to the accompanying drawings.

As shown in FIG. 1, the furnace body of the melting furnace 20 has a steel plate 2
1 and firebrick 22. 1st
The figure shows a main part of the furnace bottom 23, and a tap hole 24 is formed in the furnace bottom 23 for tapping the molten material contained in the furnace. The hot water outlet 24 is formed by inserting a graphite block 26 inside a through hole 25 which is opened in a cylindrical shape through the steel plate 21 and the refractory brick 22. This graphite block 26 has an upper blowing nozzle 27 built therethrough. This upper blowing nozzle 27 has a protrusion 2 that protrudes below the hot water spout 24.
The air outlet 29 penetrates from the side wall of the graphite block 8 to the upper part of the inner wall of the graphite block 26, and its air outlet 29 is divided into two upper and lower halves. This upper blowing nozzle 27 is the hot water outlet 2
They are provided at multiple locations in the circumferential direction of No. 4 at equal intervals. The air outlet 29 is provided so as to face the sand 30 filled in the hot water outlet 24,
Since the air outlet 29 is located at the upper part of the inner wall of the graphite block 26, the air is blown downward.

FIG. 2 shows that the upper blowing nozzle 27 is provided through the refractory brick 22, and an annular slit 27 is formed in the graphite block 26 along the circumferential direction of the spout 24.
a, which faces the inside of the hot water outlet 24 and communicates with the outlet 29.

Furthermore, an opening/closing gate 31 is provided at the bottom of the hot water outlet 24 to close the opening. This opening/closing gate 31 has a built-in lower blow-off nozzle 32, which is provided so as to penetrate from the outer wall to the inner wall of the opening/closing gate 31. The blow-off port 33 of the lower blow-off nozzle 32 is provided so as to face the sand 30 filled in the spout 24, and is erected in the center of the closed part 34 of the opening/closing gate 31 so as to blow the air upward. It's summery. In this way, the lower blowout nozzle 3
2 protrudes upward from the closing portion 34 of the opening/closing gate 31, so a flapper gate as shown in the figure is adopted as the opening/closing gate 31. If a slide gate is used, it should have a structure that allows for not only horizontal movement but also vertical movement. The opening/closing gate 31 is equipped with a drive device 35 such as a hydraulic cylinder or a motor for operating the opening/closing gate 31. A control device 36 is connected to this drive device 35 for inputting its operating signal. This control device 36 is formed of, for example, a microcomputer, and is configured to open an on-off valve 37 connected thereto in response to the above-mentioned activation signal.
For example, a solenoid valve is adopted as the on-off valve 37. A gas supply system 38 is connected to the upper blow-off nozzle 27 and the lower blow-off nozzle 32. This gas supply system 38 consists of a gas supply pipe 39 and a cylinder 40 containing an inert gas or an air compressor (not shown). The above-mentioned on-off valve 37 is provided to adjust the amount. These control device 36, on-off valve 37 and gas supply system 38
constitutes a gas supply means 41 that supplies inert gas or air to the upper blow-off nozzle 27 and the lower blow-off nozzle 32 in synchronization with the opening operation of the opening/closing gate 31. Note that inert gases include, for example, Ar and
Adopt _N2 grade.

Next, the operation of the above embodiment will be described.

Before putting scrap, etc. into the melting furnace 20, the spout 24 is closed with an opening/closing gate 31, and sand 30 is filled into the spout 24 from inside the furnace to close it. When filling this sand 30, a gas supply system 38 is connected to an upper blowing nozzle 27 provided in the inner wall of the graphite block or refractory material, and a lower blowing nozzle 32 provided in the inner wall of the opening/closing gate 31.
Supply a smaller amount of inert gas or air. This is to prevent the sand 30 from entering the blow-off nozzles 27 and 32, but the on-off valve 37 at this time may be operated manually or input into the control device 36 in advance. And the blowing nozzle 27,3
Sand 30 is filled into the spout 24 from inside the furnace while blowing out a small amount of inert gas or air from the furnace.

In this way, the hot water outlet 24 is closed with the sand 30, and the melting and refining process is started.

After the melting and refining process is completed, a ladle (not shown) is positioned directly below the tap 24, and the opening/closing gate 31 is opened to discharge the molten material in the furnace. Even if the opening/closing gate 31 is opened, if the sand 30 is baked, it will stick inside the spout 24, and the sand 30 will not fall down naturally. Therefore, when the opening/closing gate 31 is opened, the operation signal of the drive device 35 is inputted to the control device 36 of the gas supply means 41, and the control device 36 controls the opening/closing valve 37 interposed in the gas supply system 38.
to open. Then, the cylinder 4 of the gas supply system 38
Inert gas or air flows from the air compressor to the gas supply pipe 39, and the above-mentioned blow-off nozzles 27, 3
2. An upper blowing nozzle 27 provided on the inner wall of the graphite block 26 blows inert gas or air downward from the top of the packed bed of sand 30. Further, the lower blowing nozzle 32 provided on the inner wall of the opening/closing gate 31 blows out inert gas or air upward from the bottom of the packed bed of sand 30, but the blowing force is only applied to the sand while the opening/closing gate 31 is open. 30 does not work. The blowing pressure of the inert gas or air is set to a pressure sufficient to destroy the packed bed of baked sand 30.

In this way, the sand 3 stuck inside the hot water outlet 24
After the packed bed of No. 0 is destroyed and the sand 30 falls and is removed, the molten material contained in the furnace will be discharged. Removal of the sand 30 from the tap 24 can be performed easily and safely, and especially when an inert gas is used, there will be no adverse effects such as oxidation on the molten material.

[Effects of the invention] In summary, according to the present invention, blowing nozzles that blow out inert gas or air facing the sand filled in the spout are provided on the inner wall of the spout and the inner wall of the opening/closing gate, and the nozzle Since the system is equipped with a gas supply means that supplies inert gas or air in synchronization with the opening operation of the opening/closing gate, the sand filled in the spout can be easily and safely removed, resulting in stable operation. Moreover, it is easy and the working time can be shortened.

[Brief explanation of the drawing]

Fig. 1 is a schematic view of the main parts showing an embodiment of the furnace bottom tapping device of the melting furnace of the present invention, Fig. 2 is a schematic view of the main parts showing an improved top blowing nozzle of Fig. FIGS. 4 and 5 are schematic diagrams showing a bottom-projection steel arc furnace, and FIGS. 4 and 5 are schematic diagrams of main parts showing a conventional structure. In the figure, 20 is a melting furnace, 23 is a furnace bottom, 24 is a spout, 26 is a graphite block, 27 is an upper blowing nozzle, 30 is sand, 31 is an opening/closing gate, 32 is a lower blowing nozzle, and 41 is a gas supply means. It is.

Claims (1)

[Scope of utility model registration request] In a melting furnace bottom discharge device for discharging molten material in the furnace from a spout formed at the bottom of the melting furnace, an opening/closing device for closing an inner wall of the spout and a lower opening of the spout. A blowing nozzle is provided on the inner wall of the gate to blow out an inert gas or air facing the sand filled in the spout, and the inert gas or air is supplied to the nozzle in synchronization with the opening operation of the opening/closing gate. A bottom discharge device for a melting furnace, characterized in that it is equipped with a supply means.