JP3924072B2 - Lance pipe for blowing powder and gas - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure for holding a refractory covering a metal tube of a powder and gas blowing lance pipe in a kneading wheel, hot metal / molten steel pan or the like.
[0002]
[Prior art]
Conventionally, this lance pipe for blowing powder and gas is so-called lance pipe, and the outer periphery of the metal tube is coated with an irregular refractory, and it is necessary to hold the coated refractory on the metal tube.
[0003]
In this lance pipe, as a means for holding the coated refractory on the metal pipe, for example, as described in Japanese Utility Model Publication No. 63-39239, V-type and Y-type studs are attached to the outer peripheral surface of the metal pipe. This is the general structure to hold. However, since the lance pipe is inserted into the high-temperature molten metal, the difference in thermal expansion between the heated metal tube and the refractory and the expansion of the stud itself cause the refractory to crack, starting from the stud. This was a cause of shortening the durability.
[0004]
Japanese Utility Model Laid-Open No. 3-89144 discloses a lance pipe whose outer peripheral surface is coated with a reducible or flammable material such as metal foil, paper, cloth, synthetic resin, etc. Is disclosed. However, in this case, the function of holding the refractory like the stud is not provided, and when the refractory is cracked, the refractory is easily peeled off and the effect of extending the durability is small.
[0005]
[Problems to be solved by the invention]
The object of the present invention is to suppress the occurrence of cracks by absorbing the stress generated by the difference in thermal expansion between the metal tube and the refractory even when inserted into a high-temperature molten metal and heated. An object of the present invention is to provide a covered refractory holding structure for a lance pipe for blowing powder and gas, which can prevent the peeling of objects and extend the durability.
[0006]
[Means for Solving the Problems]
The present invention includes a metal tube, a support member erected at each of two upper and lower positions of the metal tube, a metal member supported by the support member in a state of surrounding the metal tube, and the metal tube. In a lance pipe for injecting powder / gas provided with a refractory material covering the outer surface of the metal tube so that the metal member is buried in a state where a gap is secured between them, a through hole is formed in the support member. On the other hand, the metal member is provided with a hooking projection inserted into the through hole so that the metal member is supported in a loosely fitted state on the support member .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The gap material burns or shrinks due to heat during the drying process to form a gap between the metal tube and the coated refractory. Combustible paper, cloth, volatile coating material, synthetic resin, vinyl tape, etc. sex walking the material that is reduced due to heat 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 operating temperature is T1, the coating thickness d is determined by the following equation.
[0009]
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 is changed from 20 ° C. to 60 ° C., the expansion coefficient a is 13 × 10 ⁻⁶ / deg.
d = 50 * 13 * 10 < ^-6 > * (600-20) 3.8 mm
It becomes.
[0010]
Furthermore, it is necessary to also considered expansion of the refractory itself, when considering the amounts of expansion 8~10 × 10 ^-6 / deg,
3.8 mm + 2.7 mm = 6.5 mm
In other words, it is necessary to cover the gap material of 3.3 mm on both sides in the range of 1.2 to 2 times the calculated value.
[0011]
If the coating thickness of the gap material is thinner than this, the effect of 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 difficult to be obtained. On the other hand, if it is too thick, it is necessary to reduce the construction thickness of the refractory itself due to the limitation of the overall diameter of the lance, and the durability is reduced in terms of corrosion resistance and strength.
[0012]
In addition, the metal member that is installed around the metal tube is a grid including a cylindrical shape, a saw piece, a rod, etc. using a metal plate such as a wire mesh, a wire, a metal rod, a wire mesh, and a lath iron plate. A hooking projection for attaching to a metal tube is provided at both ends thereof.
[0013]
The hooking protrusions are supported in a loose-fitting state through, for example, through holes in a support member that is planted at two positions above and below the metal tube, and the metal member is supported by the hooking protrusions at two positions above and below. Otherwise, there is no connection with the metal tube.
[0014]
As a result, even when the metal member is heated in a state of covering the refractory, the metal tube has a gap formed by contraction or removal of the gap material, and is supported by the support member in a loosely fitted state. It performs a separate expansion and contraction action to prevent the coated refractory from peeling due to the difference in thermal expansion from the metal tube.
[0015]
The planting position of the support member is the upper part near the suspended part and the upper part of the discharge hole on the circumference of the metal tube of the refractory covering part.
[0016]
Thereby, the range of the metal tube corresponding to the location where the lance pipe is heated at high temperature by the molten metal can eliminate the influence of the thermal expansion difference between the coated refractory and the metal tube in the gap formed by the coating of the gap material.
[0017]
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. It suffices if the hole can be inserted into the hole.
[0018]
The refractory material to be coated may be a conventionally used refractory material such as a cast refractory material or a spray material, and the material can be selected and used according to the use conditions.
[0019]
【Example】
Example 1
Figure 1 shows a first example of Ransupai flop before drying treatment by section.
[0020]
In the figure, the metal tube 2 is covered with a gap material 3 on the entire peripheral surface, which is a refractory-covered portion above the discharge hole 4, and 2 above the metal tube 2 and above the discharge hole 4. Support members 5 of metal members 6 are provided at the locations. The metal member 6 is provided with a plurality of metal rings 61 made of metal rods 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 suspended lattice. is doing. Then, one or more hooking projections 7 can be attached to or detached from the metal rings 61 at both ends of the metal member 6 by a bolt type, a hook type, or the like in a fixed state.
[0021]
The hooking projections 7 are inserted into through holes 51 for attachment provided in the upper and lower support members 5 and are locked to the support member 5 by the tip hooking portions 8 thereof. The tip engaging portion 8 is preferably formed larger than the L-shaped through hole 51 such as T, U, Y, etc. in order to prevent disconnection as shown in the figure.
[0022]
The through hole 51 of the support member 5 is formed by attaching and detaching the engaging protrusion 7 by screwing using a hinge type or curved plate when the engaging protrusion 7 of the metal member 6 is fixed to the metal ring 61. It is good to make it freely. The number and position of the hooking projections 7 to be attached to the metal ring 61 needs to take into account the hooking balance disposed on the metal pipe 2 of the metal member 6, and in this embodiment, it is supported at one place above and below. It is a state to do.
[0023]
Then, the entire peripheral surface while burying the metal member 6 coated with a refractory 9, obtaining Ransupai flop and dried. A gap is formed between the metal tube 2 and the refractory 9 by burning or shrinking the gap material 3 by heat during the drying process.
[0024]
When this lance pipe was used for hot metal desulfurization, the refractory was peeled off at an average of 100 to 120 ch in the conventional pipe, whereas in the present invention, no peeling phenomenon occurred even at 236 to 300 ch or more.
[0025]
Example 2
In the example of FIG. 2, metallic member made 16, while crossing a plurality of metal bars molded surrounds placed spirally, which engagement projections 7 similar to that shown in Figure 1 the support member 5 The entire peripheral surface is in a loosely fitted state, supported in a state away from the outer peripheral surface of the metal tube 2 except for the portion of the support member 5, supported at a distance from the metal tube 2, and embedded with the metal member 16. Is covered with refractory 9 .
[0026]
Example 3
In the example of FIG. 3, metallic steel member 26, a combination of ring 27 and rod body 28 by a metal rod which was then in a grid, the other is carried out in the same construction as that of Example 1.
[0027]
In the example of FIG. 4, metallic steel member 36 is obtained by the wire mesh 37 in a cylindrical shape and the other is carried out in the same construction as that of Example 1.
[0028]
【The invention's effect】
According to the present invention, even when 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, and cracks can be suppressed. Since the refractory is constrained by the metal pipe, the refractory is prevented from being peeled off from the crack, and a highly durable lance pipe is obtained.
[Brief description of the drawings]
FIG. 1 shows a lance pipe by a cross section before drying treatment .
FIG. 2 shows another example of a metal member .
FIG. 3 shows still another example of a metal member .
FIG. 4 shows still another example of a metal member .
[Explanation of symbols]
2 Metal tube 3 Gap material 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

Claims (1)

A metal tube,
  A support member planted in each of the upper and lower positions of the metal tube;
  A metal member supported by the support member in a state of surrounding the metal tube;
  A refractory covering the outer surface of the metal tube so that the metal member is buried in a state where a gap is secured between the metal tube and the metal tube;
In the lance pipe for blowing powder and gas with
  While forming the through hole in the support member, the metal member is provided with a hooking projection inserted into the through hole so that the metal member is supported in a loosely fitted state on the support member. A lance pipe for blowing powder and gas.

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