JP2001059685A - Ceiling cover for ladle preheater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a temperature rise of a refractory during ladle preheating and to effectively prevent an occurrence of a crack or a partial crack of the refractory by providing a shell to become a base material, the refractory lined on the shell, and a cooling metal tube embedded in the refractory. SOLUTION: A shell 2 of the ceiling cover 1 is molded in a disc-like state. Then, a burner mounting hole is perforated at a center of the shell 2, an exhaust hole is perforated at its outer periphery and a piping mounting hole is perforated at its intermediate part. A refractory 3 is formed, for example, of a plastic refractory, and lined on the shell except the respective hole parts. Further, a cooling metal tube 4 is formed, for example, of a stainless steel tube, embedded in the refractory 3, and held by a hanging fitting mounted at the shell 2. Meanwhile, an anchor hardware 6 is formed of an oxidation resistant material, brought at its one end into contact with the tube 4, and embedded in the refractory 3. Thus, in the case of preheating a ladle, the refractory 3 is effectively cooled by the tube 4 and the hardware 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceiling lid of a ladle preheating apparatus for preheating a ladle used for refining outside a furnace.

[0002]

2. Description of the Related Art A ladle refining method is used for finish refining molten steel that has been melted or further pre-refined in an electric furnace. In this ladle refining method, molten steel is stored in a ladle, and while the molten steel is heated by arc heat from an electrode provided on a ceiling lid above the ladle, argon gas is supplied from a porous plug provided at the bottom of the ladle. This is a treatment method in which an inert gas such as the above is forcibly blown into the molten steel to agitate the molten steel to perform desulfurization or deoxidation.

[0003] Since the ladle accommodates high-temperature molten steel, the inside of the ladle is made of a refractory material, and is preheated by a ladle preheating device before use in order to prevent the temperature of the contained molten steel from lowering.

FIG. 4 is a schematic configuration diagram illustrating an example of a ladle preheating device. In the figure, a column 12 provided vertically on a base 11 has a rotating shaft 13 that rotates around its axis.
Is provided. The rotation shaft 13 includes a forward and reverse rotation drive of a motor 14 provided on the support 12, a driving gear 15 a provided on the shaft of the motor 14, and a driven gear 1 provided on the rotation shaft 13.
5b rotates around the axis of the column 12.

[0005] A horizontal arm 16 is provided above the rotating shaft 13, and at one end of the horizontal arm 16 is provided a ceiling lid 18 suspended by a wire 17.
The cylinder is moved up and down via the wire 17 by the operation of the cylinder 19.

[0006] Although not shown, the ceiling lid 18 has a structure in which a refractory is lined below a steel shell as a base material, and has a burner 20 at the center thereof. A combustion gas pipe 21 and an air pipe 22 are connected to the burner 20.

At the time of the ladle preheating operation, the ladle T is placed at a predetermined position, and the horizontal arm 16 is rotated by driving the motor 14 to move the ceiling lid 18 directly above the ladle T. By operation, the ceiling lid 18 is put on the pot T.
After that, the ladle T is preheated by the burner 20. When the preheating of the ladle T is completed, the ceiling lid 18 is raised and then moved horizontally. Thereafter, the ladle T is transported to accommodate the molten steel.

[0008] By this ladle preheating operation, the inside of the ladle T is preheated to, for example, about 1600 ° C. At the same time, burner 2
Due to the radiant heat from zero and the radiant heat from the ladle T, the refractory lining the ceiling lid 18 is also exposed to high temperatures. When the refractory of the ceiling lid 18 is exposed to a high temperature, the heat causes cracks in the refractory, and when the crack progresses, the refractory may be partially missing.

The ceiling lid 18 is rotated and raised and lowered every time a ladle preheating operation is performed, so that cracks generated in the refractory are promoted. In addition, when an oxygen-enriched burner is used as the burner 20 to shorten the preheating time and preheat to a higher temperature, cracks occur in the refractory earlier.

A ceiling lid used in a high-temperature environment, such as a ceiling lid of a ladle preheating apparatus, is disclosed in Japanese Patent Application Laid-Open No. 62-93047. This ceiling lid has an outer shell in which a number of water circulation chambers are defined on the outer surface of a steel shell lined with a refractory. During use, cooling water is circulated through the water circulation chamber to cool the ceiling lid.

However, in this ceiling lid, since the water circulation chamber is provided outside the steel shell, the effect of suppressing a rise in the temperature of the refractory provided inside the steel shell is small.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to suppress a temperature rise of a refractory during a ladle preheating operation, thereby preventing cracks in the refractory and partial loss of the refractory. An object of the present invention is to provide a ceiling lid for a ladle preheating device.

[0013]

SUMMARY OF THE INVENTION The gist of the present invention is characterized by comprising an iron shell as a base material, a refractory lined in the iron shell, and a cooling metal tube buried inside the refractory. This is the ceiling lid of the ladle preheating device. This ceiling lid is preferably embedded in the refractory with the anchor hardware in contact with the cooling metal tube.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A ceiling lid of a ladle preheating apparatus according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view showing an example of the ceiling lid of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is a partially enlarged view of FIG. The ceiling lid 1 includes an iron shell 2, a refractory 3, a cooling metal tube 4, a suspension fitting 5, and an anchor 6.

The steel shell 2 is disk-shaped, and has a burner mounting hole 2a at the center, an exhaust hole 2b at two locations near the outer periphery, and a pipe mounting hole 2c at two intermediate portions.

The refractory 3 is made of, for example, a plastic refractory to which stainless steel fiber is added. The refractory 3 is lined with the steel shell 2 except for the portions where the burner mounting holes 2a, the exhaust holes 2b, and the pipe mounting holes 2c are formed. I have.

The cooling metal tube 4 is made of, for example, JIS SUS
The stainless steel pipe specified in 304 is buried in the refractory 3 over almost the entire area where the refractory 3 is lined, and water is supplied to the positions of two pipe mounting holes 2 c provided in the steel shell 2. It has a mouth 4a and a drain 4b. As shown in FIG. 3, the cooling metal tube 4 is held by a hanging metal fitting 5 attached to the steel shell 2.

The anchor metal 6 is preferably made of an oxidation-resistant material.
For example, it is made of stainless steel specified in JIS SUS310S, and one end is in direct contact with the cooling metal tube 4.
Alternatively, the cooling metal pipe 4 is buried in a refractory in a range where the cooling metal pipe 4 is provided in a state of being indirectly contacted via the hanging metal fitting 5. The anchor metal 6 has a role as a reinforcing material of the refractory 3, and also has a role of transmitting heat of the refractory 3 to the cooling metal pipe 4 and effectively cooling the refractory 3.

The ceiling lid 1 has a burner mounted in a burner mounting hole 2a, and an exhaust pipe and a water supply port 4 in an exhaust hole 2b.
A water supply pipe is connected to a, and a drain pipe is connected to the drain port 4b, and attached to the ladle preheating device shown in FIG. During the preheating work, the cooling water is sent from the water supply pipe to the cooling metal pipe 4, and the cooling water circulated in the cooling metal pipe 4 is discharged from the drain pipe. The refractory 3 is cooled by a cooling metal pipe 4 through which cooling water circulates and an anchor metal 6 provided in contact with the cooling metal pipe 4.

[0021]

As described above, according to the ceiling lid of the ladle preheating device of the present invention, since the metal pipe for cooling is buried inside the refractory, it is lined when the ladle is preheated. The refractory can be effectively cooled. Therefore, cracks are less likely to occur in the refractory, and the cooling effect of the refractory can be further enhanced by providing an anchor metal in contact with the cooling metal pipe inside the refractory.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a ceiling lid of a ladle preheating device.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a partially enlarged view of FIG. 2;

FIG. 4 is a schematic configuration diagram illustrating an example of a ladle preheating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceiling lid 2 Iron shell 3 Refractory 4 Cooling metal tube 5 Hanging fitting 6 Anchor hardware 11 Base 12 Support 13 Rotation shaft 14 Motor 15a Drive gear 5a 15b Follower gear 16 Horizontal arm 17 Wire 18 Ceiling lid 19 Cylinder 20 Burner 21 Combustion gas piping 22 Air piping

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F27D 1/14 F27D 1/14 Z 1/18 1/18 A

Claims (2)

[Claims] 1. A ceiling lid for a ladle preheating apparatus, comprising: an iron shell as a base material; a refractory material lined in the iron shell; and a cooling metal tube embedded in the refractory material. 2. The ceiling lid of a ladle preheating apparatus according to claim 1, wherein the anchor metal is buried inside the refractory in contact with the cooling metal pipe.