JPH0421725B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for repairing a blast furnace wall.

[Prior Art] When a blast furnace wall is damaged, a method of repairing it by press-fitting a thermosetting refractory material into the damaged part has been conventionally practiced.

To explain this example with reference to FIG. 3, when the stave main body 2 attached to the steel shell 1 is melted and damaged due to long-term operation and the cooling pipe 3 of the stave is exposed, a hole 4 is opened in the steel shell 1. A press-fit pipe 5 is provided in this opening, and a thermosetting monolithic refractory is inserted from there.
_M2 is press-fitted.

On the other hand, methods of spraying monolithic refractories have also been proposed, as disclosed in Japanese Unexamined Patent Publications Nos. 57-181306 and 58-141309.

[Problems to be Solved by the Invention] However, in the above-mentioned spraying method, the level of contents in the furnace is reduced to below the repair position during repair, so it is limited to repair at relatively high positions, and There are operational problems such as unstable operation at times, and even healthy furnace walls may be damaged during scale reduction.

On the other hand, although the above-mentioned press-fitting method has advantages such as not requiring reduction in size, thermosetting refractory materials do not harden unless the atmospheric condition is 100°C or higher, so in the part A where the cooling pipe 3 is exposed, Because the temperature is low, it does not harden, and even if it is press-fitted, it falls off immediately, and there is almost no hardening.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a method for repairing a melted part of a blast furnace wall by press-fitting a monolithic refractory through an opening in a steel shell. The structure is such that a low-temperature curing refractory is sprayed in advance onto the exposed portion of the cooling means exposed due to melting damage, and then a thermosetting refractory is press-fitted.

[Function] In experiments conducted by the present inventor, it was predicted that even if spraying is performed when the scale is not reduced, that is, when there are contents in the furnace around the melted part, the distance that the sprayed material will reach will be small. On the contrary, it was found that a distance of approximately 500 mm could be sufficiently reached through the gap between the charges. Therefore, in the present invention, as a first step, a low-temperature hardening (self-hardening) refractory is sprayed onto the cooling means, such as the exposed portion (cooling pipe) of the stave or cooling plate. In this case, since the refractory is low-temperature hardening, it adheres well to cooling pipes and the like and reliably hardens there, and since it is sprayed onto the target surface at a certain speed, the adhesion strength is high.

By the way, refractories that harden at low temperatures have recently been developed, and it may be possible to repair them by press-fitting them, but it is difficult to handle due to the use of a special binder, and although it is expensive, it has poor strength and adhesion. is low. Therefore, this method cannot achieve the objective.

In the present invention, after the low-temperature curing refractory is sprayed, as a second step, a conventionally commonly used thermosetting refractory is press-fitted. This thermosetting refractory exhibits high compressive strength when fully cured.

[Specific Examples of the Invention] The present invention will be explained in more detail below with reference to the drawings.

First, as shown in Fig. 1A, a hole 4 is made in the steel shell 1, and a blowing pipe 5 whose tip opening is directional is inserted, and the charge 6 is present without being reduced in length. In this state, low-temperature curing refractory material M ₁ is sprayed toward the cooling pipe 3 exposed due to melting damage. The refractory material M ₁ discharged from the tip of the spray tube 5 passes through the gap between the charges 6 and reaches the exposed cooling pipe 3, where it hardens. The spray pipe 5 is rotated around its axis and sprayed onto the upper melted part.

After the hardening of the refractory M ₁ has progressed or has been completed, a press-fit tube 7 is attached to the opening 4, and the thermosetting refractory M ₂ is press-fitted therethrough. As a result, the melted part is composed of low-temperature hardening refractory _M1 and thermosetting refractory
Filled and repaired by M ₂ .

Here, the low-temperature hardening refractory is desirably one that hardens at 100° C. or lower in view of the main purpose of the present invention, and for example, cement-based self-hardening mortar is used. Among them, "HTMKS2" manufactured by Nippon Kurukosha Co., Ltd. is suitable.

However, although this refractory has high adhesion strength,
Compressive strength is low at around 220Kg/ ^cm2 . Therefore, the second
For the step, a conventionally commonly used thermosetting mortar (for example, "Prijiect #695" or "Prijiect #695K" manufactured by Plibrico) or a silicate mortar is used. This means that the compressive strength is
It is extremely high at 400-500Kg/ ^cm2 .

Therefore, since the low-temperature curing refractory is firmly attached to the exposed portion by spraying and the initial compressive strength is ensured by press-fitting the thermosetting refractory, a stable repair effect can be obtained over a long period of time. By the way, with the conventional spraying method and press-in method, the service life was about 3 to 4 hours to about 2 weeks, but according to the present invention, the service life is about 2 weeks.
Durability times ranged from 1 week to 7 weeks.

On the other hand, it is preferable to use a stud 10 shown in FIG. 2 prior to press-fitting. This stud 10 is
A large number of piano wires are folded, bundled together, and the tips of the wires are tied with burnt material, such as plastic binding cord, and then inserted through the opening 4. After insertion, the binding cord is inserted. is burnt out by the heat of the charge, so each piano wire exhibits restoring force and the whole opens like a petal. As a result, this stud 10
acts as an anchor for the press-fit material _M2 .

[Effects of the Invention] As described above, according to the present invention, since the low-temperature curing refractory is first attached to the exposed part by spraying, it can be firmly attached, and then the thermosetting refractory is press-fitted. Therefore, a repair area with high compressive strength can be formed. Of course, problems associated with scale reduction can also be resolved.

[Brief explanation of drawings]

Figure 1A is a construction diagram of the first stage of the present invention, Figure 1B is a construction diagram of the second stage, Figure 2 is a diagram of the installation of studs that are preferably used in combination, and Figure 3 is a repair using the conventional press-in method. FIG. 1...Iron shell, 3...Cooling pipe, 4...Open hole,
5... Shot pipe, 7... Press-fit pipe, M ₁ ... Low temperature curing refractory.

Claims (1)

[Claims] 1 In a method of repairing a melted part of a blast furnace wall by press-fitting a monolithic refractory through an opening in the steel shell, a low-temperature hardening refractory is sprayed in advance onto the exposed part of the cooling means that has been exposed due to the melting damage. , a method for repairing a blast furnace wall, which comprises subsequently press-fitting a thermosetting refractory.