JP2000297988A - Water-cooled panel for furnace cover and water-cooled furnace cover for arc furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-cooled panel and a water-cooled furnace lid for an arc furnace furnace lid which can be provided at a low cost while the life of the arc furnace lid is improved. A refractory brick (2) and a cooling pipe (6) through which cooling water flows are cast into a cast iron (3), and each refractory brick (2) has a furnace inside projecting from the cast iron (3). The inner end face of the refractory brick 2 and the part cast into the cast iron 3 are formed in a shape larger than the width of the central part, and the furnace inner surface of the cast iron 3 holds the slag 4 attached to the furnace lid. Are provided, and the panels 1 are continuously arranged on a frame so as to form an annular shape, and an electrode insertion opening is formed in the center.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the dissolution of metallic materials,
The present invention relates to a water-cooled panel and a water-cooled furnace lid for a furnace lid provided in an arc furnace used for refining molten metal.

[0002]

2. Description of the Related Art FIG. 4 is a longitudinal sectional view of a conventional arc furnace. A refractory furnace cover 15 having an electrode insertion opening 14 through which an electrode 13 is inserted is provided at the upper part of a furnace shell 12 of the arc furnace so as to be openable and closable. Have been. The refractory furnace lid 15 receives high heat during operation and melts down, so the furnace lid has to be replaced and the cost is high.

Therefore, Japanese Patent Application Laid-Open No. 53-107729 discloses an electrode 1 as shown in FIG.
Except for the inverted conical portion having the electrode insertion port 14 through which the electrode 3 is inserted, the entire furnace lid is made of a steel plate, and a spiral passage 16 is formed therein to form a water-cooled jacket furnace lid 17. It is disclosed that a metal film 18 having a property of reflecting radiant heat and having high thermal conductivity is provided on the inner surface side of the furnace 17 to increase durability.

However, in the water-cooled jacket-type furnace lid made of a steel plate as described above, as the operation of the arc furnace is repeated, cracks occur in the steel plate portion, and water leakage often occurs from the water-cooled jacket. In an arc furnace using a water-cooled jacket made of steel for the furnace wall and furnace lid, the amount of heat removed by the cooling water is about 10% of the total energy required by the arc furnace, and half of the total energy is further reduced. Heat removal by cooling water from the furnace lid. Amid increasing demands for improved energy efficiency and reduction of carbon dioxide gas to prevent global warming, arc furnaces can also reduce heat loss due to cooling water without increasing refractory consumption, There is a need for more energy efficiency.

Further, Japanese Patent Laid-Open Publication No. Sho 50-142709 proposes a furnace lid for an arc furnace using a cooling water pipe and an appropriate number of coolers in which bricks are cast in a casting such as cast iron or copper casting. . In this furnace lid, heat loss due to cooling water is reduced. However, since the furnace inner surface temperature of the casting constituting the cooler body reaches 1000 ° C. or more, several hundreds to
With the use of thousands of charges, cracks due to thermal stress and embrittlement due to structural change of the casting occur, and as they progress, the casting is worn out, and the problem that the cast brick is worn out and falls off occurs. I have. Furthermore, cracks generated on the casting surface may propagate to the cooling water pipe, causing water leakage.

In Japanese Patent Application No. 11-26767, refractory bricks arranged in a plurality of rows at regular intervals and cooling water pipes are inserted between rows of the refractory bricks so as to expose the end face inside the furnace. We proposed a water-cooled panel for the furnace wall and lid of the existing arc furnace. In this panel, the surface of the cast iron does not reach 700 ° C. at which the progress of the structural change of the cast iron starts, and wear of the cast iron, and wear and fall of the brick do not occur.

[0007]

When the panel is applied to a furnace wall and a furnace lid of an arc furnace, slag and other deposits in the furnace are stably retained on the furnace wall, and a water-cooled jacket type panel is used. In comparison, heat loss due to cooling water was reduced. However, since the width of the furnace inner end face of the refractory brick is smaller than the width of the furnace outer end face and the convex portion for stably holding the in-furnace deposits such as slag is rectangular, the furnace lid has When applied, deposits in the furnace, such as slag, fell down inside the furnace, that is, downward, and it was difficult to stably hold them. The heat insulating effect of the slag and other deposits in the furnace is great, and when applied to the furnace lid, the heat loss due to the cooling water cannot be reduced more stably than when applied to the furnace wall. In addition, the frequency with which the bricks cast in the panels are exposed to the furnace increases, and the speed at which the bricks are worn out increases.

An object of the present invention is to provide a water-cooled panel and a water-cooled furnace lid for an arc furnace, which can be provided at a low cost while improving the thermal efficiency and the life of the arc furnace lid.

[0009]

A water-cooling panel for a furnace lid of an arc furnace according to the present invention is a panel in which a plurality of refractory bricks and a cooling pipe for flowing cooling water are cast into cast iron. The inside of the furnace protrudes from the cast iron, and the protruding end face of the refractory brick and the part cast into the cast iron are formed to have a shape larger than the width of the central part. A slag catcher for holding slag to be attached is provided.

The water-cooled furnace lid of the arc furnace according to the present invention is characterized in that the water-cooled panels for the furnace lid of the above-described arc furnace are continuously arranged on a frame and arranged in an annular shape, and an electrode insertion opening is formed in the center. Features.

[0011]

FIG. 1 is a longitudinal sectional view of a water-cooled panel for a furnace cover of an arc furnace according to the present invention. The panel 1 has a plurality of refractory bricks 2 cast into a cast iron 3. The inside of the furnace of each refractory brick 2 protrudes from the cast iron 3, and the slag 4 attached to the furnace inside of the furnace lid is securely held together with the slag catcher 5. Is formed so as to be wider than the width. On the other hand, each of the refractory bricks 2 has a size substantially equal to the furnace inner end face in order to prevent a portion cast in the cast iron 3 from falling off from the cast iron 3 and to measure heat transfer between the refractory bricks 2 and the cast iron 3. Formed. Therefore,
It is preferable that the refractory brick 2 has a drum-like shape. As the refractory brick 2, for example, a magnesia carbon material having excellent spalling resistance is used.

A cooling pipe 6 through which cooling water flows is cast in the cast iron 3. Further, on the inside of the furnace of the cast iron 3, in order to hold the slag 4 attached to the inside of the furnace of the furnace lid, a metal slag catcher 5 having a shape for locking the slag is provided by cast-in or the like. By stably attaching the slag to the furnace lid, the temperature of the furnace inner surface of the furnace lid can be reduced.

FIG. 2 is a plan view showing a part of a furnace lid formed by the panel of the present invention, and FIG. 3 is a longitudinal sectional view of the same. The panel 1 is formed flat, and the furnace center side is formed in a fan shape with a shorter side as compared with the furnace peripheral side. The panel 1 is continuously arranged to form an annular shape, and an electrode insertion port 8 can be formed in the center. It is. The panel 1 is supported by a frame 9. Since the furnace lid can be formed flat by arranging the flat panels, the processing and construction of the furnace lid become easier as compared with the conventional conical furnace lid.

The cooling pipes 6 formed in the panel 1 may be formed as continuous serpentine pipes. However, as shown in FIGS. 2 and 3, the cooling pipes 6 formed in the panel 1 are independently formed. The cooling water inlet 10 and the cooling water outlet 11 of each cooling pipe 6 are provided.
May be connected directly to the header tubes 7 and further connected to the header tubes 7. The connection between the cooling pipe 6 and the header pipe 7 makes it possible to reduce the amount of processing compared to the cooling pipe 6 using a serpentine pipe that requires a large number of bendings, and to obtain an inexpensive panel 1. Becomes

[0015]

According to the present invention, the slag is stably adhered to the water-cooled furnace lid by the refractory brick and the slag catcher to lower the surface temperature. It is possible to stably reduce the life and extend the life of the water-cooled furnace lid compared to the conventional case.

Since the water-cooled furnace lid is formed of a flat panel and the header pipes are connected to each other, processing and construction are easy, and an inexpensive water-cooled furnace lid can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a water-cooled panel for a furnace lid of an arc furnace according to the present invention.

FIG. 2 is a plan view showing a part of a furnace lid formed by the panel of the present invention.

FIG. 3 is a vertical sectional view of a furnace lid formed by the panel of the present invention.

FIG. 4 is a longitudinal sectional view of a conventional arc furnace.

FIG. 5 is a longitudinal sectional view of a conventional water-cooled jacket furnace lid.

[Explanation of symbols]

1: Panel 2: Refractory brick 3: Cast iron 4: Slag 5: Slag catcher 6: Cooling pipe 7: Header pipe 8: Electrode insertion port 9: Frame 10: Cooling water inlet 11: Cooling water outlet 12: Furnace shell 13: Electrode 1
4: Electrode insertion port 15: Refractory furnace lid 16: Spiral passage 17: Water-cooled jacket furnace lid 18: Metal film

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 7/02 H05B 7/02 B 7/12 7/12 A F term (Reference) 3K084 AA11 CA07 CB02 DA04 DA14 4K014 CD04 CD15 4K045 AA04 BA02 RA09 RA16 4K051 AA05 AB09 MA08 4K063 AA03 AA04 AA12 BA02 BA13 CA01 CA05 FA51 FA53

Claims (2)

[Claims] 1. A panel in which a plurality of refractory bricks and a cooling pipe for flowing cooling water are cast into cast iron, wherein each of the refractory bricks has a furnace inner side protruding from the cast iron and a protruding refractory brick furnace. The inner end face and the part to be cast into the cast iron are formed in a shape larger than the width of the central part, and a slag catcher for holding slag attached to the furnace lid is provided on the furnace inner surface of the cast iron. A water-cooled panel for a furnace lid of an arc furnace. 2. The water cooling system for an arc furnace according to claim 1, wherein the water cooling panels for a furnace cover of the arc furnace according to claim 1 are continuously arranged on a frame and arranged in an annular shape, and an electrode insertion port is formed in the center. Furnace lid.