JP2000034516A - Refractory-coated holding structure of lance pipe for blowing powdery material and gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refractory-coated holding structure of a lance pipe for blowing powdery material and gas by which the occurrence of crack is suppressed by absorbing the stress caused by thermal expanding difference between a metallic pipe and the refractory even when the lance pipe is inserted into high temp. molten steel and heated, and the durability can be extended by preventing the detachment of the refractory from the metallic pipe even when the crack is caused on the lance pipe. SOLUTION: Supporting members 5 are elected at the upper position of the metallic pipe 3 constituting the lance pipe 1 and at the upper position near spouting holes 4 in the lower part of the metallic pipe. A gap material 3 forming the gap between the metallic pipe and the coated refractory by burning off or shrinking with the heat at the time of dry-treating between the metallic pipe and coated refractory 9, is coated on the whole peripheral surface of the refractory coated part at the upper part from the spouting holes of the metallic pipe. On this outside, metal-made members 6 are disposed in the state of surrounding the metallic pipe and projections 7 for hanging arranged at the upper and the lower end parts of this metal-made members are supported to the upper and the lower supporting members in the fitting state. Further, the surface of the gap material 3 is coated with the refractory in the state of embedding the metallic members.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refractory holding structure for covering a metal pipe of a lance pipe for injecting powder and gas in a mixed iron wheel, a hot metal or a molten steel ladle, and the like.

[0002]

2. Description of the Related Art Conventionally, a lance pipe for blowing powder and gas, which is called a lance pipe, has a metal pipe covered with an irregular-shaped refractory, and it is necessary to hold the coated refractory on the metal pipe. .

In this lance pipe, as means for holding the coated refractory on a metal pipe, for example, Japanese Utility Model Publication No. Sho 6
As described in Japanese Patent Application Laid-Open No. 3-39239, it was a general structure to attach V-shaped and Y-shaped studs to the outer peripheral surface of a metal tube and hold them by the studs. However, since the lance pipe is inserted into the high-temperature molten metal, cracks occur in the refractory starting from the stud due to the difference in thermal expansion between the heated metal pipe and the refractory and the expansion of the stud itself. This was the cause of shortening the durability.

Further, Japanese Utility Model Laid-Open No. 3-89144 discloses that the outer peripheral surface of a metal core pipe of a lance pipe is covered with a scalable or combustible material such as metal foil, paper, cloth, synthetic resin, or the like. It is disclosed to coat shaped refractories. However, in this case, the function of holding the refractory as in the case of the stud is not provided, and when a crack occurs in the refractory, the refractory tends to peel off and the effect of extending the service life is small.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to suppress the occurrence of cracks by absorbing the stress generated due to the difference in thermal expansion between a metal pipe and a refractory, even when inserted into a high-temperature molten metal and heated,
An object of the present invention is to provide a coated refractory holding structure for a powder / gas blowing lance pipe capable of preventing the refractory from falling off from a metal tube even when a crack occurs and extending the durability.

[0006]

SUMMARY OF THE INVENTION The present invention is a coated refractory holding structure for a powder / gas blowing lance pipe in which a refractory is coated on the outer surface of a metal tube with a coated refractory, which constitutes the lance pipe. A support member is planted at each of the upper position and the upper position near the lower discharge hole in the refractory coating portion of the metal tube, and the entire peripheral surface of the refractory coating portion above the discharge hole of the metal tube is referred to as a metal tube. It is covered with a gap material to form a gap between the coated refractory, and a metal member is arranged outside the metal tube so as to surround the metal tube, and the metal member has hooking projections at both upper and lower ends thereof. The upper and lower support members are loosely supported, and the surface of the gap member is covered with a refractory in a state where the metal member is buried.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A gap material is formed by burning or shrinking by heat during a drying process to form a gap between a metal tube and a coated refractory. Paper, cloth, volatile coating material, synthetic material, etc. Combustible materials such as resin and vinyl tape or materials that can be reduced by heating can be used.

[0008] The coating thickness of the gap material is determined by the diameter of the metal tube. For example, assuming that the diameter of the metal tube is D, the expansion coefficient of the metal tube is 11 to 15 × 10 ⁻⁶ / deg, and the temperature during operation is T1, the coating thickness d is determined by the following equation.

D = D × (11−15 × 10 ⁻⁶ ) × T1 Therefore, when the diameter of the metal tube is 50 mm and the temperature of the metal tube changes from 20 ° C. to 60 ° C., the expansion coefficient a is 13 ×
Assuming 10 ⁻⁶ / deg, d = 50 × 13 × 10 ⁻⁶ (600−20) 3.8 mm.

Further, it is necessary to take into account the expansion of the refractory itself, and taking into account the expansion of 8 to 10 × 10 ⁻⁶ / deg, 3.8 mm + 2.7 mm = 6.5 mm. A coverage of 0.2 to 2 times, that is, 3.3 mm on both sides is required.

If the thickness of the gap material is smaller than this, the effect of the expansion allowance is lost, and the refractory and the metal tube are brought into close contact with each other, so that the holding effect of the present invention is hardly obtained. On the other hand, if the thickness is too large, the construction thickness of the refractory itself needs to be reduced due to the limitation of the entire diameter of the lance, and the durability in terms of corrosion resistance and strength decreases.

The metal member provided around the metal tube so as to surround the metal tube may be made of a metal plate such as a wire mesh, a wire, a metal rod, a wire mesh, a lath iron plate, or the like. Are processed into a lattice shape or a helical shape, and hooking projections for attaching to a metal tube are provided at both ends.

The hooking projections are supported in a loosely fitted state, for example, through through holes of a support member erected at two upper and lower positions of the metal tube. The metal member is a hooking projection at the two upper and lower positions. Other than being supported, there is no connection with the metal tube.

Thus, even if the metal member is heated while being covered with the refractory, there is a gap formed by contraction or removal of the gap material from the metal pipe, and the metal member is supported by the support member in a loosely fitted state. Therefore, it performs a stretching action separately from the metal pipe, and prevents the coated refractory from peeling off due to a difference in thermal expansion from the metal pipe.

The support members are set up on the upper portion near the hanging portion and the upper portion of the discharge hole on the circumference of the metal tube around the refractory coating portion.

Thus, the area of the metal pipe corresponding to the place where the lance pipe is heated at a high temperature by the molten metal is reduced by the gap formed by the coating of the gap material to eliminate the influence of the difference in thermal expansion between the coated refractory and the metal pipe. it can.

Further, the through hole of the support member does not need to be a perforation formed in the support member, and may be an annular gap formed by a mating plate. In short, the engaging projection is not fixed and restrained. It suffices if the hole can be inserted in the loose fit state.

The refractory to be coated may be a commonly used refractory such as a cast refractory or a spraying material.
Materials can be selected and used according to usage conditions.

[0019]

Embodiment 1 FIG. 1 is a cross-sectional view showing a first example of a coated refractory holding structure for a lance pipe to which the present invention is applied.

In the figure, a metal tube 2 of a lance pipe 1 is shown.
In addition, the gap member 3 is coated on the entire peripheral surface, which is the refractory coating portion above the discharge hole 4, and the metal member 6 is provided at two places above the metal pipe 2 and above the discharge hole 4. A support member 5 is provided. The metal member 6 is provided with a plurality of metal rings 61 made of metal rods and arranged so as to surround the metal tube 2, and the metal rings 61 are connected by two to six coiled wires 62 to form a hanging grid. are doing. One or more hooks 7 are detachably attached to the metal rings 61 at both ends of the metal member 6 by a bolt type, a hook type, or the like, or are attached in a fixed state.

The hooking projections 7 are inserted into through holes 51 for mounting provided in the upper and lower support members 5, and are locked to the support members 5 by the front end hook portions 8. As shown in the figure, the tip engaging portion 8 prevents
In addition to the L shape, it is preferable to form the T, U, Y shape, etc., larger than the through hole 51.

The through hole 51 of the support member 5 is formed by fixing the hooking projection 7 of the metal member 6 to the metal ring 61 by screwing using a hinge or a curved plate. It is good to make attachment and detachment freely. The number and position of the hooking projections 7 attached to the metal ring 61 need to consider the hooking balance arranged on the metal tube 2 of the metal member 6, and in the present embodiment, they are supported at one position each at the top and bottom. It is in a state to do.

The lance pipe 1 is obtained by covering the entire peripheral surface with the refractory 9 in a state where the metal member 6 is buried.

When this lance pipe was used for hot metal desulfurization, the conventional pipe peeled off the refractory at an average of 100 to 120 ch, whereas in the case of the present invention, 236 to 3
The peeling phenomenon did not occur even at 00 ch or more.

Embodiment 2 FIG. 2 shows a second embodiment of the metal member in the coated refractory holding structure of the present invention. In the example of FIG. 1, the metal member 16 covered with the gap material 3 and surrounding the metal tube 2 is spirally formed while surrounding a plurality of metal rods, and is surrounded and installed. The projection 7 for engaging the support member 5
The metal member 16 is supported in a state where the metal member 16 is buried in a state in which the metal member 16 is buried. The surface of the refractory 9 is covered with the refractory 9 to form a holding structure.

Embodiment 3 FIG. 3 shows a third embodiment of the metal member in the coated refractory holding structure of the present invention. In the example shown in the figure, a metal tube 26 covered with a gap member 3 is formed as a metal member 26 by combining a ring 27 of metal rods and a rod 28 in a lattice shape. It is implemented with a similar structure.

FIG. 4 shows a fourth embodiment of the coated refractory holding structure according to the present invention. In the example shown in the figure, a metal net 37 is installed as a metal member 36 in a cylindrical shape on a metal tube 2 covered with a gap material 3, and the other structure is the same as that of the first embodiment. .

[0028]

According to the present invention, even if the lance pipe is repeatedly heated at a high temperature, the stress generated by the difference in expansion between the metal pipe and the refractory is absorbed by the relative movement in the longitudinal direction of the lance pipe, thereby suppressing cracking. Becomes possible, and furthermore, the refractory is restrained by the metal pipe, so that the refractory peeling from the crack is suppressed.
A highly durable lance pipe is obtained.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a coated refractory holding structure according to the invention in cross section.

FIG. 2 shows another example of the coated refractory holding structure of the present invention.

FIG. 3 shows still another example of the coated refractory holding structure of the present invention.

FIG. 4 shows still another example of the coated refractory holding structure of the present invention.

[Explanation of symbols]

Reference Signs List 1 lance pipe 2 metal pipe 3 gap material
Reference Signs List 4 discharge hole 5 support member 6, 16, 26, 36 metal member 7 projection for engagement 8 engagement portion 9 refractory 27 ring
28 rod body 37 wire mesh 51 through hole 61 metal ring 62 coiled wire

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuhiko Fujii 1850 Minato, Wakayama-shi, Wakayama Prefecture Kurosaki Ceramics Co., Ltd. Sales Department, First Division, Wakayama Sales Office F-term (reference) 4K002 BF01 4K013 CA17 CB03

Claims (1)

[Claims] 1. A powder having a refractory coated on the outer surface of a metal tube.
What is claimed is: 1. A refractory coating holding structure for a gas injection lance pipe, wherein a support member is planted at each of an upper position and an upper position near a lower discharge hole in a refractory coating portion of a metal pipe, From above, the entire peripheral surface of the refractory coating portion is covered with a gap material for forming a gap between the metal pipe and the coated refractory, and a metal member is arranged outside the metal pipe in a state surrounding the metal pipe, The metal member supports the engaging projections at the upper and lower ends in a loosely fitted state on the upper and lower support members. Further, the surface of the gap material is refractory in a state where the metal member is buried. Retained refractories holding structure for coated powder / gas blowing lance pipe.