JPH04320794A - Interior repair method of cylinder-shaped refractory molded products - Google Patents

Abstract

PURPOSE:To enhance the accurate properties and anti-wearing properties of the terminal section by laying out a refractory substance-made cylindrical body whose length is equivalent to a cylinder-shaped refractory molded product intended for repair and a dummy cylindrical body on the rear side, moving an expander jig having a slanting squeeze plane, expanding the cylindrical body and repairing the molded product. CONSTITUTION:A refractory substance-made cylindrical body 3 having therminal plasticity and setting properties whose length is equivalent that of a cylinder-shaped refractory molded product intended for repair is laid out whereas a dummy cylindrical body 8 is laid out on the rear end of the cylindrical body 3. The cylindrical body 3 is expanded in size by moving an expander jig M having a slanting squeeze plane 5, thereby repairing the cylinder-shaped refractory molded product 2. A stopper 7 is installed to the tip of the cylinder member which surrounds a mandrel M. As a result, the tensile force applied to the cylindrical body 3 during its pulling out time is supported with the stopper 7 by way of the dummy cylindrical body 8. Since the size is expanded under this condition, the rear end of the cylindrical body 3 is molded in a straight manner and the durability of the cylindrical body is extended by enhanced accurate and anti-wearing properties of the terminal section.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to the repair of damaged inner surfaces of cylindrical refractory molded bodies lined with refractory material, such as discharge holes in molten metal processing furnaces and atmospheric furnaces, molten metal return conduits, etc. Regarding the repair method that strengthens the repair of the end part, specifically, for example, a refractory molded body having a single-hole type through-hole such as an immersion lance or an immersion nozzle through which a treatment agent is injected in a converter tapping hole, ladle smelting, etc. Alternatively, the present invention relates to a method for repairing a damaged inner surface of a submerged tube or the like of a vacuum degassing apparatus.

0002

BACKGROUND OF THE INVENTION There are several known methods for repairing a cylindrical refractory molded body lined with a refractory material. For example, a method and apparatus for repairing a tap hole in a converter (Japanese Unexamined Patent Publication No. 61
-110711 Publication) uses a roller diameter expanding device to spread and press the repair material. Since this method uses a tubular core material, the so-called buckling phenomenon occurs in which the tubular core material returns to its original diameter after diameter expansion. This causes the refractory to not maintain its shape after crimping. In addition, as a conventional technique, there is a press-in method (Japanese Patent Laid-Open No. 61-8
No. 124), spraying method (Japanese Unexamined Patent Publication No. 60-24311)
However, all of them have low density after repair work, low wear resistance and erosion resistance, short service life, and high cost.

[0003] As a repair method for solving the above-mentioned problems of the prior art, when repairing a cylindrical refractory material, a pre-designed cylindrical body of a thermoplastic hardening material is subjected to sufficient sensible heat to make the thermoplastic hardening material thermoplastic. Insert it inside the cylindrical refractory material to be repaired,
Next, the diameter of the cylindrical body is expanded by moving a diameter expanding jig with an inclined squeeze surface that applies sufficient pressure to bring about a shape change to the cylindrical body exhibiting thermoplasticity, and the inside of the cylindrical refractory material to be repaired is A method of crimping repair was published in patent application No. 1-1991.
I proposed this in issue 25.

[0004] None of the above conventional methods takes into account the aspect of the end portion of the cylindrical refractory material to be repaired. Refractory molded bodies with single-hole through holes such as immersion lances and immersion nozzles for injecting processing agents in the above-mentioned converter tapping holes, ladle scouring, etc., or damaged inner surfaces of immersion pipes of vacuum degassing equipment, etc. During repair, there is a problem in that the shape of the refractory part cannot be maintained, especially at the ends, because there is no flow stopper for the repair material. That is, the flow of molten metal discharged from the discharge hole becomes turbulent due to the unhealthy construction body. For example, in a tap hole of a converter, the melt flux is disturbed, and solid steel called bare metal adheres to the tip of the tap hole. If this metal is left unattended, it will gradually accumulate and grow until it eventually blocks the tap hole. Furthermore, this turbulent state of the molten metal significantly increases the heat dissipation area of the high-temperature body and releases a large amount of heat dissipation energy, which is not economically advantageous.

[0005]

The present invention relates to an improvement of the repair method disclosed in the above-mentioned Japanese Patent Application No. 199125/1999, and particularly relates to the improvement of the repair method disclosed in the above-mentioned Japanese Patent Application No. 199125. When repairing the refractory cylindrical body by inserting it into the molded body and moving the diameter expanding jig having an inclined squeeze surface while holding the rear end of the cylindrical body with a stopper, the above-mentioned By improving the density of the end of the cylindrical refractory molded object to be repaired and preventing a decline in wear resistance, the discharge flow from the discharge hole of molten metal is maintained in a healthy flow state, and a large amount of heat radiation energy is released. The object of the present invention is to provide a method for repairing the inner surface of a cylindrical refractory molded body, which prevents this.

[0006]

[Means for Solving the Problems] The present invention involves inserting a cylindrical body made of thermoplastic and hardenable refractory material into a cylindrical refractory molded body to be repaired, and When repairing by expanding the diameter of the refractory cylindrical body by moving a diameter expanding jig having an inclined squeeze surface while holding the refractory with a stopper, the length of the cylindrical refractory molded body to be repaired is approximately equal to the length of the refractory molded body. The refractory cylindrical body is placed along the length of the refractory cylinder, a dummy cylinder is placed on the rear end side of the refractory cylinder, and a diameter expanding jig having an inclined squeeze surface is moved to A method for repairing the inner surface of a cylindrical refractory molded body, the method comprising repairing the cylindrical refractory molded body by expanding the diameter of the cylindrical body, the dummy cylinder being placed on the rear end side of the refractory cylinder. A short cylindrical body made of thermoplastic/curable refractory material is arranged as a body, and a cylindrical rigid spacer is arranged in front of the stopper,
The method for repairing the inner surface of a cylindrical refractory molded body as described above, which comprises moving a diameter expanding jig having an inclined squeeze surface to expand the diameter of the refractory cylindrical body to repair the cylindrical refractory molded body. A cylindrical body made of thermoplastic and hardening refractory material is inserted into a cylindrical refractory molded body to be repaired, and the rear end of the cylindrical refractory body is held with a stopper while pressing the inclined squeeze surface. When repairing the refractory cylindrical body by moving a diameter expanding jig having a diameter expanding jig, the refractory cylinder is adjusted to a length approximately equal to the length of the cylindrical refractory molded body to be repaired. At the same time, a dummy cylinder is placed on the tip side of the refractory cylinder, and a diameter expanding jig having an inclined squeeze surface is moved to expand the diameter of the refractory cylinder to form a cylindrical refractory. This is a method for repairing the inner surface of a cylindrical refractory molded product, which is characterized by repairing the molded product.

[0007]

[Operation] The present invention will be explained in detail below.

First, in the present invention, a cylindrical body made of thermoplastic and hardenable refractory material used as a crimping repair material will be explained. The refractory material for the thermoplastic/curable refractory cylindrical body in the present invention is appropriately selected and used from the following examples.

In the case of a converter tapping hole, magnesia-graphite-metal A1 is 70-90%-5-25%-1-7%
Blended refractory material, magnesia-dolomite-graphite-metal A1 40-60%-10-50%-5-20
- Refractory material containing 1 to 7% of calcia, magnesia, graphite, and metal Mg of 10 to 50% - 40 to 70% -
Refractory materials containing 5-25% are used. In the case of the immersion tube of the vacuum degassing treatment equipment, in addition to the refractory material made of the same material as the converter tap hole, alumina-graphite of 70 to 95%-5 is used.
~30% blended refractory material, alumina-silicon carbide-graphite-metal A1 50-80%-5-20%-5-2
A refractory material containing 5%-1 to 7% is used. In the case of refractory molded bodies with single-hole through holes such as immersion lances or immersion nozzles that blow treatment agents into during ladle scouring, etc., refractory materials containing 70-95%-5-80% bauxite-graphite, mullite- Alumina 50-80%-20
~50% blended refractory material, zirconia 100 refractory material,
Zirconia-alumina-graphite 1~40%-4
Refractory material containing 0-70% - 10-30%, refractory material containing zirconia zircon 20-50% - 50-80%, alumina-silicon carbide-graphite-metal A1 6
A refractory material containing 0 to 85%, 5 to 20%, 5 to 20%, and 1 to 7% can be selected and used depending on the application.

[0010] A binder such as a thermoplastic resin or pitch is appropriately selected and added to the above-mentioned refractory material, kneaded, and formed into a cylindrical body. The thermoplastic resin has a particle size of 0.
A phenol resin having a thickness of 1 mm or a synthetic resin or various modified resins having a residual carbon amount similar to the residual carbon amount after heating the phenol resin can be used. As the above-mentioned pitch, either petroleum-based pitch or coal-based pitch can be used as long as the particle size is in the range of 0.1 to 1.0 mm.

[0011] In the case of a thermoplastic resin, the amount of the binder added is preferably 3 to 12 parts by weight based on 100 parts by weight of the refractory aggregate, taking into account the fluidity during repair and the strength of the constructed body after repair. It is. In the case of pitch, 5 to 18 parts by weight is suitable for 100 parts by weight of the refractory aggregate in terms of porosity, shape retention, etc. after repair. These thermoplastic and hardenable refractories are molded into cylindrical bodies with appropriate outer diameter, wall thickness, and length depending on the repair application.

Next, the cylindrical refractory molded body to be repaired will be explained.

[0013] In the present invention, the cylindrical refractory molded body to be repaired is advantageously repaired during the operation of the main apparatus or in the heat between operating cycles. Figure 1 is a patent application filed in 1999.
125 is an explanatory diagram of the repair process when the technology disclosed in No. 125 is applied to the repair of a tap hole in a converter, and as shown in FIG. body 3
is set and inserted into the cylindrical refractory molded body 2 to be repaired. When the inserted thermoplastic/curable refractory cylindrical body 3 exhibits the required thermoplasticity due to the sensible heat possessed by the repaired cylindrical refractory molded body 2, as shown in FIGS. 1(b) and 1(c). When the rod 6 is pulled out while the stopper 7 is operated, the diameter of the thermoplastic/hardenable refractory cylinder 3 is expanded by squeezing the diameter expanding jig M made up of the plug 4 having an inclination 5. Pressure is applied to the repaired cylindrical refractory molded body 2, and a uniformly dense repair layer can be formed simply and in a short time.

In addition, when the repaired cylindrical refractory molded body 2 is cooled down, or when the temperature drops to such an extent that sufficient heat cannot be applied to the refractory cylindrical body 3, the cylindrical refractory body to be repaired If the material molded body 2 is heated and the temperature is raised to the extent that sufficient heat can be applied to the refractory cylindrical body 3,
It is possible to obtain a construction body similar to that obtained by hot repair. Incidentally, if there is a slight shortage of heat to maintain the refractory cylinder 3 in a thermoplastic state, it is also possible to supplement the heat with a heated plug 4.

In the construction method as described above, FIG.
As shown in d), in order to pull out the plug 4 from inside the cylindrical refractory molded body 2 to be repaired, the stopper 7 is released and then the plug 4 is further pulled out. Because the support at the rear end of is open,
The contact part with the plug 4 is pulled out to the outside of the furnace, and the outside end of the cylindrical refractory molded body 2 to be repaired has molding defects such as curling up and pulling off of the refractory cylindrical body 3. Become.

[0016] The feature of the present invention is to provide a method for effectively performing this end forming, and the first invention, as shown in Fig. 2, is a cylinder made of thermoplastic/curable refractory material. The body 3 is inserted into the cylindrical refractory molded body 2 to be repaired, and while holding the rear end of the refractory cylindrical body 3 with a stopper 7, a diameter expanding jig M having an inclined squeeze surface 5 is inserted. When moving and repairing the refractory cylindrical body 3 by expanding its diameter, the refractory cylindrical body 3 is arranged to have a length approximately equal to the length of the cylindrical refractory molded body 2 to be repaired, and A dummy cylinder 8 is placed on the rear end side of the refractory cylinder 3, and a diameter expanding jig M having an inclined squeeze surface 5 is moved to expand the diameter of the refractory cylinder 3 into a cylindrical shape. Repair the refractory molded body 2. Since the stopper 7 is provided at the tip of a cylindrical member (not shown) surrounding the mandrel M, the tensile force applied to the refractory cylindrical body 3 when the mandrel M is pulled out is absorbed by the dummy cylindrical body 8. It is supported by a stopper 7 via.

In this construction method, in the process of detaching the plug 4 from the cylindrical refractory molded body 2, as shown in FIG. is expanded in diameter while being supported by the tip of the dummy cylindrical body 8, so the rear end of the refractory cylindrical body 3 is formed straight.

The dummy cylindrical body 8 is a cylindrical combination of objects such as hard rubber cylinders and steel pieces that can withstand the pulling force during pulling out of the mandrel M and whose diameter can be expanded.
A rigid cylinder or the like can be used in which the cylindrical body is connected with an elastic body such as a spring so as to be expandable in diameter. In addition, when using the dummy cylindrical body 8 made of a refractory material processed into a rigid body, by using the cylindrical rigid body spacer 9 used in the second aspect of the present invention to be described later, the dummy cylindrical body made of a refractory material is formed by the plug 4. body 8
Even if the refractory cylindrical body 3 is broken, the supporting function of the rear end of the refractory cylindrical body 3 still functions, so that the rear end of the refractory cylindrical body 3 can be formed straight.

The removal of the dummy cylindrical body 8 is shown in FIG. 2(e).
), after the repair operation, at the position where the repair device is evacuated, the position of the stopper 7 is shifted so that the mandrel M can pass through, and the mandrel M can be pulled out by retreating.

As shown in FIG. 3, a second aspect of the present invention is to use a short thermoplastic/curable refractory cylinder as a dummy cylinder 8 disposed on the rear end side of the refractory cylinder 3. At the same time, a cylindrical rigid spacer 9 is placed in front of the stopper 7, and a diameter expanding jig M having an inclined squeeze surface 5 is moved to expand the diameter of the refractory cylindrical body 3 to form a cylindrical refractory. The molded body 2 is repaired. In this construction method, the body of a short thermoplastic/curable refractory cylinder used as the dummy cylinder 8 is supported by a cylindrical rigid spacer 9, and the refractory cylinder 8 serving as the dummy cylinder is supported by a cylindrical rigid spacer 9. Since the end portion of the refractory cylinder 3 is supported by the stopper 7, the rear end of the refractory cylindrical body 3 is formed straight. Further, the short thermoplastic/curable refractory cylinder 8, which is a dummy cylinder, can be easily separated by retracting the repair device after the repair operation, and can be easily removed at the retracted position.

As shown in FIG. 2, the third aspect of the present invention is to insert a cylindrical body 3 made of thermoplastic/curable refractory material into a cylindrical refractory molded body 2 to be repaired, and When repairing the refractory cylindrical body 3 by expanding its diameter by moving the diameter expanding jig M having the inclined squeeze surface 5 while holding the rear end of the refractory cylindrical body 3 with the stopper 7, the above-mentioned repair is carried out. A cylindrical body 3 made of refractory having a length approximately equal to the length of the cylindrical refractory molded body 2 of interest is arranged, and a dummy cylindrical body 10 is disposed on the tip side of the cylindrical body 3 made of refractory, and an inclined A diameter expanding jig M having a squeeze surface 5 is moved to expand the diameter of the refractory cylindrical body 3 to repair the cylindrical refractory molded body 2.

As the dummy cylindrical body 10 used in this construction method, a short cylindrical body made of thermoplastic/curable refractory material, a cylindrical refractory brick, etc. can be used. This dummy cylindrical body 10 blocks radiant heat from inside the furnace during repair, and suppresses excessive heat supply to the front end surface (inside the furnace) of the refractory cylindrical body 3.

[0023]

[Example] The construction method of the present invention was applied to two tapping holes of a converter. The heat size of the converter is 270Ton/ch, the standard inner diameter of the tapping hole is Φ200mm, the material is tar-impregnated calcined magnesia, and after 5 charge blowing, the temperature during blowing of the repaired part is 800℃.
℃, non-blowing temperature about 800℃, inner diameter before repair is Φ250m
It was m. Drill this tapping hole to make an inner diameter of Φ300.
After processing to mm, repairs were carried out. The construction method employs a method in which a dummy cylinder 8 and a dummy cylinder 10 are placed on the front end and rear end of the refractory cylinder 3, respectively, and the rear end dummy cylinder 8 is provided with a cylindrical rigid spacer 9. Surrounded by Furthermore, since a dummy cylinder made of refractory material was used, its composition is shown in Table 1. The thermoplastic/curable refractory cylinder 3 is made of magnesia-graphite-metal A1 (85%-
A cylindrical body was used, which was made by adding 4% phenolic resin to a refractory material (10%-3%), kneading it, and molding it into a cylindrical shape.

[0024]

[Table 1]

The refractory cylindrical body 3 has an inner diameter of 140 mmφ.
, an outer diameter of 270 mmφ, a length of 300 mm, and 5 pieces were used during construction, and the dummy cylindrical body 11 at the tip has an inner diameter of 140 mmφ,
Two pieces with an outer diameter of 270 mmφ and a length of 90 mm are used, and the dummy cylindrical body 9 at the rear end has an inner diameter of 140 mmφ and an outer diameter of 270 mm.
One piece was used with mφ and length of 300 mm. The total length at this time is 1980 mm, and the effective repair length is 1500 mm.

A mandrel M with a refractory cylinder 3 set therein is inserted into the tap hole of the converter. The shape of the mandrel M at this time is a plug diameter of 200 mmφ, a length of 300 m, a taper portion θ=9°, a rod diameter of 120 mmφ, and a length of 2500 mm.

[0027] The stopper diameter is fixed at 270 mmφ,
Pulling was started (pulling force at this time was 10T, construction time was 1 minute and 45 seconds).Finally, when the plug reached the rear dummy position, the stopper was released and the rod was pulled to complete the construction.

[0028] Below is sleeve brick 1 furnace cost (3500ch)
The repair was repeated every 25 channels without replacement during blowing or blowing. Of the 140 repairs per furnace, 34 were carried out during blowing and 11 were carried out during non-blowing. The operational results are shown in Table 2.

[0029]

[Table 2]

[0030]

[Effect of the invention] ■ The durability of the refractory cylindrical body is higher than that of the conventional 25 mm due to the improved compactness and abrasion resistance of the cylindrical body end.
% was also extended.

[0031] As a result, the converter operating rate improved by 0.5%, the number of repair man-hours decreased by 13 man-hours, and the basic unit of repair refractory material decreased by 0.008 kg/T.

[0032] By improving the shape of the end of the cylindrical body, the tapping flow was rectified.

[0033] As a result, the amount of bare metal on the outside of the tapping hole furnace was drastically reduced, and the work load was reduced. In addition, there is no molten steel scattering outside the receiving ladle during tapping, and the yield is 0.3%.
Improved. Furthermore, slag entrainment at the final stage of steel tapping was reduced, and the quality of the steel improved.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional repair process according to the present invention. (a) An explanatory diagram of a mode in which a cylindrical body made of refractory is set in a tapping hole of a converter. (b) An explanatory diagram of a drawing start mode of crimping. (c) An explanatory view of the state immediately before the end of pulling out and crimping. (d) An explanatory diagram of a mode in which the stopper is released from the fixation, the rod is pulled out, and construction is completed.

FIG. 2 is an explanatory diagram of the repair process of the method of the present invention. (a) An explanatory diagram of a mode in which a cylindrical body made of refractory is set in a tapping hole of a converter. (b) An explanatory diagram of a drawing start mode of crimping. (c) An explanatory view of the state during pull-out and crimping. (d) An explanatory view of the state immediately before the end of pulling out and crimping. (e) An explanatory diagram of a mode in which the stopper is released from the fixation, the rod is pulled out, and construction is completed.

FIG. 3 is an explanatory diagram of a repair process using a spacer according to one embodiment of the method of the present invention. (a) An explanatory diagram of the state immediately after the completion of pull-out and crimping. (b) An explanatory view of a mode in which the refractory cylindrical body is supported after its diameter has been expanded at the end of drawing and crimping.

[Explanation of symbols] 1... Steel tap hole shell
2... Cylindrical refractory molded body to be repaired 3... Cylindrical body made of thermoplastic/curable refractory material 4... Plug 5... Tapered portion 6
...Rod 7...Stopper
M...Mandrel 8...Dummy cylindrical body at rear end
9... Cylindrical rigid spacer 10... Tip dummy cylindrical body

Claims (3)

[Claims] [Claim 1] A cylindrical body made of thermoplastic/curable refractory material,
The refractory cylindrical body is inserted into the cylindrical refractory molded body to be repaired, and while holding the rear end of the refractory cylindrical body with a stopper, a diameter expanding jig having an inclined squeeze surface is moved to remove the refractory cylindrical body. When repairing by expanding the diameter of the refractory, the refractory cylinder is arranged to have a length approximately equal to the length of the cylindrical refractory molded object to be repaired, and a dummy is placed on the rear end side of the refractory cylinder. A cylindrical refractory molding characterized in that a cylindrical refractory molded body is repaired by arranging a cylindrical body and expanding the diameter of the refractory cylindrical body by moving a diameter expanding jig having an inclined squeeze surface. How to repair the inside of the body. 2. A short thermoplastic/hardenable refractory cylinder is placed as a dummy cylinder on the rear end side of the refractory cylinder, and a cylindrical rigid spacer is placed in front of the stopper. The cylindrical refractory molded article according to claim 1, wherein the cylindrical refractory molded article is repaired by moving a diameter expanding jig having an inclined squeeze surface to expand the diameter of the refractory cylinder. How to repair the inner surface of. [Claim 3] A cylindrical body made of thermoplastic/curable refractory material,
The refractory cylindrical body is inserted into the cylindrical refractory molded body to be repaired, and while holding the rear end of the refractory cylindrical body with a stopper, a diameter expanding jig having an inclined squeeze surface is moved to remove the refractory cylindrical body. When repairing by expanding the diameter of the refractory, the refractory cylindrical body is placed at a length approximately equal to the length of the cylindrical refractory molded body to be repaired, and a dummy cylinder is placed on the tip side of the refractory cylindrical body. A cylindrical refractory molded body is repaired by arranging a cylindrical refractory molded body and expanding the diameter of the refractory cylindrical body by moving a diameter expanding jig having an inclined squeeze surface. How to repair the inner surface of.