JPH0630831Y2 - Molten metal furnace - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is of a type in which a lid such as a hood is brought into close contact with a furnace body to melt, smelt or reduce metal in a state where the inner space is almost sealed. Related to the molten metal furnace,
The present invention relates to a molten metal furnace that does not impair the soundness of a portion that comes into close contact with the lid when charging or discharging molten metal.

[Prior Art] In recent years, in a molten metal furnace used for melting, refining or reducing a metal, the space inside the furnace on the surface of the metal bath is often not opened to the atmosphere. This is because the quality of the metal, the productivity, or the gas generated in the furnace is controlled by sealing the space in the furnace and making it vacuum (or low pressure), pressurizing it to a pressure higher than atmospheric pressure, or filling it with an inert gas. This is because a great advantage occurs in terms of processing.

For example, molten gas can be degassed (dehydrogenation, deoxygenation, denitrification, etc.) and decarburized by keeping the furnace space near vacuum, so that so-called high-grade steel, low-alloy steel and special steel are melted or refined. To do so, various vacuum melting furnaces and vacuum refining furnaces are used. On the other hand, if the pressure inside the furnace is increased,
Since there are advantages such as being able to guide the gas to processing equipment without using an air blower and without mixing the air, increasing the gas density to promote the metallurgical reaction, and suppressing the evaporation of additional elements in the molten metal, the converter furnace In smelting reduction furnaces and the like, the furnace opening is often sealed with a hood, and the gas generated from the molten metal is often contained in the furnace space to increase the pressure. In addition, in a furnace for storing molten metal or the like, in order to prevent metal oxidation and evaporation of additional elements, the furnace space on the metal bath surface may be filled with an inert gas such as argon.

In order to seal the furnace space of the molten metal furnace as described above, the entire furnace may be placed in a sealed space such as a vacuum tank or a pressurizing chamber, but a lid such as a hood is provided at the opening of the furnace body. It may be covered with a close contact. The larger the capacity of the molten metal furnace, the more difficult the former becomes from the viewpoint of installation space and equipment cost. Therefore, the latter method is generally adopted. However, in the latter case, since it is necessary to ensure close contact between the furnace body and the lid, the adhered part (joint surface) may adhere or deposit metal ingots ejected from the furnace, or damage or deformation. It is necessary to maintain the soundness of the close contact part by not doing so.

A converter is an example of a molten metal furnace that seals the inner space of the furnace by closely attaching a hood to the opening of the furnace body.In the conventional converter, in order to ensure close contact between the furnace body and the hood. This means was applied only to the hood side. An example thereof is disclosed in Japanese Examined Patent Publication No. 62-20253. That is, in the converter, a metal 2'which also holds refractory material
No special equipment or parts are provided other than attaching the furnace to the furnace port 1, but as shown in FIG. 6, on the hood side, the first seal ring B1 made of water-cooled cast iron is attached to the lower end of the skirt B1 'that can be raised and lowered.
By providing a'and a second seal ring B1b 'made of steel pipe and lowering the skirt B1', these two seal rings B1a 'and B1b' are brought into close contact with the furnace mouthpiece 2 '. In this case, the high temperature slag adhering to the furnace mouthpiece 2'is destroyed by the reduction force of the first seal ring B1a 'and the thermal shock of water cooling, so that the two seal rings B1a', B1.
1b 'can be surely brought into close contact with the furnace mouthpiece 2'to seal the gas in the furnace and increase the pressure in the furnace space. A similar example is disclosed in Japanese Utility Model Publication No. 63-11168. this is,
A cover that covers the seal packing on the lower end surface of the hood is pivotably attached to the periphery of the lower end of the hood via a link mechanism so that the cover can be opened and closed, that is, the cover is opened by the link mechanism when the hood descends. It is a thing.

Such an example is not limited to a converter, but is similarly applied to, for example, a smelting reduction furnace. In a relatively small capacity molten metal furnace, such as the above-mentioned vacuum melting furnace, vacuum refining furnace, and storage furnace, the furnace body can be removed by a simple means such as cleaning the contact portion (joint surface) with air or a brush. The contact with the hood (lid) was ensured. In any case,
The molten metal furnace itself was not equipped with any device or component for maintaining the soundness of the contact portion.

[Problems to be Solved by the Invention] In the above-mentioned conventional molten metal furnace, the contact portion between the furnace body and the hood may impair the soundness when the molten metal is charged or discharged (hot water is discharged). There is. That is, in the above-mentioned converter, smelting reduction furnace, various vacuum furnaces and storage furnaces,
In general, molten metal is charged and discharged through an opening that covers a lid such as a hood, but in such a case, molten metal often spills and adheres to the contact portion, and especially when melting When the metal is discharged and transferred to another container, the contact portion may directly receive the radiant heat from the metal bath surface to be thermally deformed.

For example, in the example of the converter described in the above-mentioned publication, molten steel is discharged (steel tapping) from a tapping tap other than the furnace tap, but the slag and a part of the molten steel remaining with the slag and the molten pig iron installation Since the insertion is performed by tilting the furnace body through the furnace opening, at this time, these molten metals may adhere (or weld) to the furnace opening, which is a close contact portion with the hood (skirt). The metal thus adhered is locally concentrated in a large amount, and since it is cooled and solidified by the start of the next refining, it cannot be easily destroyed. In addition to this, strong radiant heat acts on the furnace opening from the metal bath surface of the steel pan or slag pan, so that the furnace opening may be overheated and deformed if not water-cooled. In this case, it is impossible to maintain the soundness of the contact portion by the above-mentioned conventional means, and it is impossible to achieve the original purpose of sealing the furnace space.

This invention was made in order to solve the above-mentioned problems, and even when molten metal is tapped or charged, the portion that is in close contact with the lid for sealing the furnace space should be protected from metal adhesion and deformation. It is intended to provide a molten metal furnace which can be maintained soundly so as not to exist.

[Means for Solving the Problems] In order to solve the above object, the molten metal furnace of the present invention is
In a molten metal furnace that operates by sealing the inner space by closely contacting the lid to the furnace body, around the opening for charging or discharging molten metal, with a contact portion with the lid, A movable cover that can cover a part or all of this contact portion is provided.

Further, it is preferable that the tip of the opening is projected outward from the contact portion.

Further, the molten metal furnace is supported so as to be tiltable, and a movable cover is rotatably provided near the contact portion of the metal furnace so that the cover is normally positioned so as not to cover the contact portion. Alternatively, a weight may be provided at the lower end of the cover.

[Operation] According to the molten metal furnace of the present invention having the above configuration,
When charging or discharging molten metal from the opening,
Since the movable cover moves and protects the close contact part with the lid body, the soundness of the close contact part is maintained, and when performing the operation (melting, refining or reducing), the cover retracts to close the close contact part. Since it is exposed, the lid can be surely brought into close contact with it to seal the space inside the furnace.

According to the molten metal furnace of the second aspect, when the molten metal (including slag) is discharged, the molten metal does not drip toward the contact portion or the furnace wall.

According to the molten metal furnace of claim 3, when the metal furnace is tilted, the cover is automatically relatively rotated to cover the contact portion,
When the metal furnace is returned to the original operating state, the cover automatically rotates relative to the original state so that the contact portion is not covered and the contact portion is opened. Therefore, it is not necessary to open / close the cover, and a drive device for opening / closing the cover is not necessary.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional view of an upper blowing converter according to an embodiment of the present invention. The converter A is a molten metal furnace in which a refractory A2 is lined in a steel shell A3, and the molten iron obtained in a blast furnace or the like is smelted and converted into steel. During refining, oxygen blown from the lance D burns C (carbon) in the hot metal, so high-temperature gas containing a large amount of CO is generated from the inside of the furnace. All the openings such as 11 are closed during refining so that the gas pressure in the furnace space A1 is increased so that the gas does not leak to reach the gas treatment facility through the duct E. That is, during refining, a skirt B1 that can be moved up and down provided at the bottom of the hood B is seated on the furnace opening 1, and a tapped steel cover C covers the tapped steel outlet 11. When the refining is completed, the skirt B1 and the lance D are raised, the converter A is tilted to the left side of the drawing by a tilting device (not shown), and the molten steel is discharged from the tapped steel outlet 11 with the lid C opened (steel tapped). ) Do. After that,
For example, the slag and a part of the molten steel are discharged by inclining to the right side of the figure, but the molten iron for the next refining is charged from the furnace port 1 in a state of being slightly inclined to the right side of the figure.

The first embodiment of the present invention is shown at the furnace opening 1 of the converter A as shown in FIG. That is, the converter A has a close contact portion 2 with the lower flange B1a of the skirt B1 around the furnace opening 1 and a rotary movable cover 3 that covers a part of the close contact portion 2. The close contact part 2 is formed by mounting seal packing 2b on the entire circumference of the upper surface of the furnace port flange 2a.
Attach this seal packing 2b to the bottom flange B1a of the skirt B1.
The periphery of the furnace opening 1 is sealed by pressing.
The cover 3 is axially attached to the bracket 5 so as to cover a part (about 90 ° in the circumferential direction) of the slag discharge side (right side in FIG. 1) of the close contact portion 2 and is rotated by the motor 4. ing. The cover 3 is a water-cooled iron plate, and is formed so that the cooling water supplied through the hollow shaft 3a circulates inside the cover 3 and is drained again from the hollow shaft 3a.

As described above, when refining and tapping are completed, converter A is
It tilts as shown in the figure and discharges the residue (slag and part of the molten steel) through a furnace opening 1 into a slag pan (not shown) placed below, in which case the cover 3 first Second from the position shown
Rotate to the position shown in the figure to protect the contact portion 2 in place. Therefore, the molten metal splashing from the furnace opening and the molten metal splashing from the slag pan at the time of this discharge hit the surface of the cover 3 and do not adhere to the contact portion 2 protected by the cover 3. Especially,
In the present embodiment, as shown in the drawing, the tip of the furnace port 1 is formed so as to project outward with respect to the close contact part 2, so that the molten metal will not contact the close contact part 2 even when the molten metal is discharged as described above. There is no fear of dripping towards. Also, above the slag pan that received the molten metal,
Although the radiant heat from the molten metal surface acts, the portion of the contact portion 2 that receives the strongest radiant heat is covered by the cover 3, so that the seal packing 2b is burned or the furnace port flange is
There is no thermal deformation of 2a.

3 and 4 show a second embodiment of the present invention. Third
As shown in the figure, the furnace port flange of the converter A (Fig. 1)
A bracket 5 is projectingly provided on the side peripheral wall of 2a, and at the tip end thereof,
A cover 6 whose upper portion is slightly bent toward the furnace port 1 side is rotatably attached to a shaft. The shaft support position 6a of the cover 6 is located closer to the lower end than the intermediate position, and a weight 7 is attached to the lower end of the cover 6 via a support member 8 so that the cover 6 normally stands in the vertical direction. Further, the shaft supporting position 6a of the cover 6 with respect to the converter A is a tilting position of about 5 ° before the start of tapping when the converter A is tilted to the right side of the drawing to discharge the molten metal containing slag from the furnace port 1. At (tilt angle θ in FIG. 4), the upper end of the cover 6 comes into contact with the peripheral portion of the furnace opening 1 as shown in FIG.
It is good to set so that it covers. Incidentally, FIG. 3 and FIG.
In the figure, members common or equivalent to those in the first embodiment are designated by the same reference numerals as in FIGS. 1 and 2.

According to the cover 6 of the present embodiment described above, simply by tilting the converter A when tapping hot water, the converter A rotates with respect to the cover 6 standing in the vertical direction. Rotating relative to the furnace A, as shown in FIG.
Cover. When the converter A is returned to the original operating state, the cover 6
Rotates relative to the converter A and stands upright in the vertical direction to open the contact portion 2 as shown in FIG. Therefore, a drive device such as a motor for rotating the cover 6 is not required at all, and the opening / closing operation of the cover 6 is not required at all, which is easy to use.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 5 shows the periphery of the tap hole 11 of the converter A shown in FIG. As shown in the figure, in the converter A, a contact surface (steel opening flange) 12 with the steel output port lid C is provided around the steel output port 11, and a slide movable cover 13 that covers almost the entire contact surface 12 is provided. Have been deployed. Contact surface 12 is tapped steel plate C
The packing C1 is a smooth surface to which the packing C1 comes into close contact, and the lid C is rotated around a support shaft by a driving device (not shown) to make a close contact surface.
The tap hole 11 is closed by pressing against. Cover 13
Is retracted during refining as shown in FIG. 1, but when the cover C is rotated to the position shown in FIG. 3 to open the tap hole 11, the cylinder 14 slides in the support frame 15. Move to the position shown in the figure to cover the entire circumference of the contact surface 12. The cover 13 is made of heat-resistant ceramics (such as silicon nitride or zirconia, which has high toughness and high thermal shock resistance), and the opening 13a slightly larger than the inner diameter of the tap hole 11 is formed on the front surface of the tap port 11. Is coming to. The cover 13
A support frame 15 for supporting the slide guide and for guiding the slide movement is fixed to the iron shell A3, and the cylinder 14 is attached to the support frame 15.

In the converter A having such a configuration around the tap hole 11 as described above, when refining is completed, the tap port C is opened, the cover 13 is moved to cover the contact surface 12, and the furnace body is tilted. When the molten steel is discharged (steeled) to a steel receiving pot (not shown), the contact surface 12 is not covered with the molten steel splashing from the steel outlet 11 or splashing from the steel receiving pot, and the steel receiving pot Since the radiant heat from does not act, the soundness of the contact surface 12 is always maintained.

As described above, in all three embodiments, the soundness of the contact portion 2 and the contact surface 12 is maintained by the covers 3 or 6 and 13, respectively. Therefore, when the converter A performs refining, the cover 3
Or the contact portion 2 and the contact surface where 6 and 13 are retracted and exposed
The skirt B1 and the tapped steel mouth C are surely brought into close contact with each other 12 to seal the furnace space A1.

The molten metal furnace of the present invention is not limited to the above embodiment in the converter, and other molten metal furnaces such as various vacuum furnaces, closed smelting reduction furnaces or inert gas sealed storage furnaces Also in, it can be implemented in the same manner.

[Effects of the Invention] According to the molten metal furnace of the present invention configured as described above, the following effects are brought about.

1) When charging or discharging the molten metal, the molten metal does not adhere to the contact portion with the lid or the contact portion is not thermally deformed.

2) Due to the effect of 1) above, the lid can be reliably brought into close contact with the furnace body at the contact portion, so that the inside of the furnace can be more completely sealed. Therefore, the inside of the furnace is vacuum (or low pressure)
The operation such as changing to high pressure, increasing the pressure, or sealing with an inert gas can be performed smoothly, and the various advantages described above can be effectively utilized.

3) In the molten metal furnace according to the second aspect, when the molten metal is discharged, there is no possibility that the molten metal drips toward the contact portion or the furnace wall.

4) The molten metal furnace according to claim 3 does not require a drive device for rotating the cover and has a simple cover structure.
It is easy to deploy in the furnace and convenient because it does not require opening and closing the cover.

[Brief description of drawings]

1 to 5 are drawings relating to an embodiment of the present invention, FIG. 1 is a vertical cross-sectional view of the entire converter, and FIG. 2 is a furnace port in a tilted state of the converter showing the first embodiment. Sectional view of part 3,
FIG. 4 is a vertical cross-sectional view of the furnace opening of the converter showing the second embodiment, and FIG. 4 is a vertical cross-sectional view of the furnace opening of the converter shown in FIG.
FIG. 5 is a vertical cross-sectional view of the steel outlet port of the converter showing the third embodiment. FIG. 6 is a vertical cross-sectional view showing a conventional converter furnace opening. 1 ... Furnace mouth, 2 ... Adhesive part, 3, 6 ... Cover, 7 ...
Weight, 11 …… Steel tap, 12 …… Adhesive surface, 13 …… Cover, A
…… Converter, B …… Hood, B1 …… Skirt, C …… Steel lid

Claims (3)

[Scope of utility model registration request] 1. A molten metal furnace which operates by sealing an inner space by closely contacting a lid with a furnace body, and around a opening for charging or discharging molten metal,
A molten metal furnace characterized in that a close contact portion with the lid is provided and a movable cover capable of covering a part or the whole of the close contact portion is provided. 2. The molten metal furnace according to claim 1, wherein the tip of the opening is projected outward from the contact portion. 3. The molten metal furnace is supported so as to be tiltable, and a movable cover is rotatably provided near the contact portion of the metal furnace so that the cover does not normally cover the contact portion. The weight is provided at the lower end of the cover so as to be positioned.
Alternatively, the molten metal furnace according to item 2.