JPH0641834B2 - Hot dismantling method for refractory lining - Google Patents

Description

TECHNICAL FIELD The present invention relates to a dismantling method performed prior to the construction of a furnace, a molten metal container, or other refractory lining for refractory lining used in the steel industry.

[Prior Art] As a molten metal container lined with a refractory, for example, a container such as a tap gutter, a mixed pig iron car, a converter, a ladle, and a tundish in the steel industry consists of a side wall and a floor (lower part), Each is lined with refractory material, and most are made up of two layers: permanent lining (perma lining) and inner lining (work lining). Since the work lining is directly damaged by hot metal (hot metal or molten steel),
Since the remaining thickness of the work lining becomes thin after using it for a relatively short period (several days to several months), it is necessary to carry out refitting repair work. Also, furnaces such as blast furnaces, converters, and electric furnaces have a structure in which refractory bricks are piled up, and it is common to extend the life by spraying repairs when the remaining thickness becomes thin, but at the end of the furnace It is necessary to dismantle and reload the refractory bricks. During these repair works, the damaged part of the lining and its surroundings, that is, the remaining work lining in the repair required area must be destroyed, but the refractory of the remaining work lining is affected by the high temperature of the molten metal and other effects. Due to this, it is often hard to sinter both inside and outside and is transformed into a rock-like strong structure.

Therefore, the dismantling of the residual work lining is not easy, as the dismantling method, for example, as shown in JP-A-58-11379, a method of disassembling by injecting a static crushing agent into the refractory lining, Alternatively, as disclosed in Japanese Utility Model Laid-Open No. 58-79314, there is a method in which a piston is driven by compressed air and a refractory lining is disassembled by a back and forth movement of a hammer.

For the dismantling of the refractory lining of the furnace, there is a method of gradually dismantling by hand using a tool called an air pick, or a method of roughly dismantling the whole using a large civil engineering machine called a backhoe. is there.

[Problems to be Solved by the Invention] In order to dismantle the refractory lining by the conventional method as described above, it is necessary to cool the furnace, the molten metal container, etc., to a temperature at which the work can be performed once, and therefore the cooling is required. Since most of the repair period is time, it is necessary to deploy a large number of spare molten metal containers, which is a problem in terms of efficiency. Further, the mechanical dismantling method using a hammer or the like requires a large impact force, so that it is difficult to dismantle only the work lining, and the perm lining is inevitably damaged. Therefore, automating the dismantling work has been a hindrance.

The object of the present invention is to eliminate the above-mentioned problems of the conventional dismantling method, to easily and accurately dismantle the required range of the furnace and the refractory lining of the container, and also to automate with inexpensive equipment. It provides a way to do it.

[Means / Action for Solving Problems] The gist of the present invention is as follows. For the hot refractory lining material to be dismantled,
A hot dismantling method for a refractory lining, which comprises blasting high-pressure water and dismantling the refractory lining with explosive steam.

2. The hot dismantling method of the refractory lining according to the above-mentioned item 1, wherein the hot refractory lining material is supplementarily heated by a burner prior to the impact of the high pressure water.

3. 3. The refractory lining according to claim 1 or 2, wherein low pressure water is jetted into a groove formed by impacting high pressure water against a hot refractory lining material to cause steam explosion. Hot dismantling method.

4. The first or second or the second or the second aspect, characterized in that the high pressure water nozzle impacts the high pressure water to blow air or water by an auxiliary nozzle that is directed to the groove to remove shavings in the groove. Method for hot disassembling the refractory lining according to item 3.

Is.

That is, the surface of the refractory lining is peeled off and disassembled by using high-pressure water collision and evaporation energy of the refractory lining in a high temperature state immediately after using a furnace, a molten metal container or the like. In the present invention, the high temperature state means a temperature range in which water evaporates and a refractory material is subjected to a temperature difference to cause a spalling phenomenon, and specifically, a temperature range of 150 to 800 ° C. is desirable. The peeling mechanism when high-pressure water is sprayed on such a high-temperature refractory is accelerated and collided when the high-pressure water is sprayed from the nozzle toward the refractory surface. At this time, the kinetic energy of water is converted into mechanical energy for peeling off the refractory surface. Water enters cracks that occur on the surface of the refractory or additional grooves that are drilled and explosively evaporates in the cracks and grooves. That is, the thermal energy of the refractory is converted into mechanical energy for peeling.

By utilizing this rapid volume expansion, the solid slag adhesion layer and the refractory surface layer can be easily peeled off.

The present invention is to dismantle the refractory lining in such a state by using high-pressure water collision and steam explosion, but the condition of high-pressure water to be impacted to give such a phenomenon is that the water pressure is 500 atm or more. It is called high pressure water, and it is most efficient to use it in the range of 1500 to 2500 atm for dismantling the refractory lining. Considering the effect on the refractory lining, it is better to keep the amount of water to 1-10 / min, which is smaller than the conventional amount. Fig. 2 shows the relationship between water volume and nozzle diameter plotted with water pressure as a parameter.
It is understood that the one with 0.5 mmφ should be selected and used according to the pressure and the amount of water.

Further, in the case of adopting a method of pre-grooving the refractory lining in the present invention, as shown in FIG.
Water is poured into it by the low-pressure water nozzle 12.

It is desirable that the groove has a width of 1 to 2 mm and a depth of 10 to 20 mm.

Also, when making such a groove by jetting high pressure water,
As the high-pressure water therefor, it is desirable that the water pressure is 1500 to 2500 atm, the nozzle tip diameter is 0.2 to 0.3 mmφ, and the water amount is 2 to 5 / min.

It is desirable that the low-pressure water injected into the groove has a water pressure of 2 to 5 atm, a nozzle tip diameter of 2 to 3 mmφ, and a water amount of 5 to 10 / min.

Further, when drilling with such a groove, shavings are generated in the groove, but it is preferable to quickly remove this shaving.
As shown in the figure, it is more effective to dispose the auxiliary nozzle 13 around the high pressure water nozzle 2 to blow off the shavings in the groove. As high pressure water, the water pressure is 1500-2500 atm and the nozzle tip diameter is
It is desirable that the amount of water is 0.2 to 0.3 mmφ and the amount of water is 2 to 5 / min.

Further, a gas such as compressed air or low-pressure water is jetted toward the groove from the auxiliary nozzle 13 arranged in the periphery. In the case of low-pressure water, it is necessary to increase the linear flow velocity more than that described above to blow off the dust, and the water pressure is 5-10 atm.
It is desirable that the amount of water is 2 to 10 mm / min. When using a gas such as compressed air, the discharge pressure is 5-10 atm and the flow rate is 50-10.
0 Nm ³ / hr is sufficient.

In addition, the sprayed water does not adversely affect the refractory material, it does not require treatment of waste water because it evaporates, and since the spray nozzle can be used without contact with the lining surface, only the reaction force of high pressure water is applied to the nozzle. Because it is only, it can be easily automated.

In the present invention, it is a method of hot treating the refractory lining, the efficiency of the disassembly, for the purpose of improving the workability by heating the required dismantling portion with a burner or the like, after further heating the method of the present invention It is also effective to give.

The heating condition in this case is that the temperature of the refractory lining is 20
It is desirable to set the temperature to 0 to 500 ° C. When you want to suspend only the surface, it is efficient to heat only the surface layer by rapid heating, and when you want to disassemble to the inside, it is efficient to control slowly heating and transmitting to the inside. .

Further, as such heating means, as shown in FIG. 5 (A), a method of heating only the surface layer by the surface combustion burner 14 or (B)
The method of heating the inside with the large-capacity burner 15 shown in is considered to be suitable. Similar results can be obtained by using electric heating or plasma heating. In FIG. 5, 16 is a slag reaction layer and 17 is a healthy layer.

[Example] Example-1 Hereinafter, the present invention will be described with reference to an example in which dismantling was performed prior to repairing a blast furnace tappipe.

FIG. 1 is an overall view showing a dismantling operation of a tap iron gutter as an embodiment example of the present invention. The side wall of the gutter before dismantling is distinguished from the surface layer to a slag adhesion layer 11, a refractory-slag reaction layer 10, a sound work lining layer 9, and a perma lining layer 8, and 7 is an outer gutter wall. The dismantling is to separate and dismantle the slag adhering layer 11 and the reaction layer 10. The dismantling work was started about 1 hour after the hot metal was completely poured. The lining surface temperature was about 950 ° C., the slag adhesion layer 10 was about 30 mm, and the reaction layer of refractory and slag was about 10 mm.

In this example, the dismantling work was carried out in a completely automated manner. That is, the high pressure water is 1500 to 3000 kg / cm ^{2 in} the water supply device 1, and the water amount is 3 to
The injection nozzle 2 has a tip discharge diameter of 0.3 mm. The jetting nozzle 2 is attached to a moving carriage 3 which can move forward and backward on a gutter. The jetting angle and the distance between the surfaces are adjusted with respect to the lining surface by an operating arm 4. Furthermore, an optical sensor 5 is attached to detect the discoloration and identify the surface condition. In order to separate the reaction layer 10 and the boundary layer of the sound work lining 9 from each other, these were disassembled by automatic operation by the automatic control device 6.

That is, the jet angle and the distance of the nozzle 2 are made proper with respect to the lining layer, and when a solid adhered substance is present, the moving speed is slowed or the water pressure of the jet is increased to increase the surface crack portion of the lining material. It was possible to carry out the dismantling work by injecting water into and exploding the steam with a large peeling effect.

Compared with the conventional work, the method according to this embodiment shortens the dismantling time from about 10 hours to about 5 hours, and reduces the amount of refractory repair required.
It was possible to reduce from 25t to about 17t. Moreover, manual work in a high-temperature atmosphere with a lot of dust was very difficult, but automation made it possible to greatly improve work efficiency and save labor.

Example-2 When disassembling a taphole, the surface was first heated by a COG burner, and high-pressure water was sprayed under hot conditions under the same conditions as in Example-1. Table 1 compares the efficiency of dismantling work depending on the surface temperature.

Example 3 V-grooves having an average width of 1.5 mm and a depth of 10 to 15 mm were preliminarily drilled by high-pressure water injection into the fireproof lining of a taphole by the method shown in FIG.
Water was poured into the groove, and it was dismantled efficiently by steam explosion and spalling by rapid cooling. The nozzle interval (the interval between 2 and 12 in FIG. 3) was 20 mm, and the nozzle moving speed was 1.6 m / min.

The results are shown in Table 2. Table 2 also shows the effect of blowing off the shavings.

[Advantages of the Invention] As described above, according to the method of the present invention, it is possible to easily and properly dismantle a refractory such as a molten metal container in a furnace without cooling it. In addition to the advantages such as improvement of the heat resistance, the necessary amount can be peeled off properly, so it has excellent effects such as saving refractories, less vibration, and easy automation with inexpensive equipment. It is a thing.

[Brief description of drawings]

FIG. 1 is an overall view of dismantling work in the embodiment of the present invention, and FIG.
The figure shows a plot of the relationship between the nozzle tip diameter and the amount of water with water pressure as a parameter.
FIG. 4 is a view showing an embodiment of a method of injecting water into the groove with low pressure water thereafter to dismantle, and FIG. 4 is a view showing an embodiment of a method of blowing shavings in the groove by an auxiliary nozzle to improve dismantling efficiency, FIGS. 5 (A) and 5 (B) are diagrams showing an embodiment relating to a method for heating the refractory lining to be disassembled by a burner and irradiating high pressure water in a hot state to improve the disassembly efficiency. 1 ... Water supply device, 2 ... Spray water nozzle 3 ... Movable carriage, 4 ... Operation arm, 5 ... Optical sensor, 6 ... Automatic control device, 7 ... Gutter outer wall, 8 ... Perm lining layer, 9 ... Work lining layer 10 …… Reaction layer, 11 …… Slag adhesion layer 12 …… Low pressure water nozzle, 13 …… Auxiliary nozzle 14 …… Surface combustion burner, 15 …… Large capacity burner 16 …… Slag reaction layer, 17 …… Healthy layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-61-1794 (JP, A) Actual development S58-79314 (JP, U) JP-B-49-6722 (JP, B1)

Claims (4)

[Claims] 1. A hot dismantling method for a refractory lining, characterized in that high-pressure water is struck against a hot refractory lining material to be dismantled, and the explosively generated steam dismantles the refractory lining. . 2. A hot dismantling method for a refractory lining according to claim 1, wherein the hot refractory lining material is supplementarily heated by a burner prior to the impact of the high pressure water. . 3. A steam explosion is generated by injecting low pressure water into a groove formed by impacting high pressure water against a hot refractory lining material to cause steam explosion. Method for hot disassembling the refractory lining according to item 2. 4. A shaving in the groove is ejected by spraying air or water with an auxiliary nozzle that directs the high-pressure water nozzle to hit the high-pressure water nozzle and directs the groove into the groove. The hot dismantling method of the refractory lining according to the first, second or third range.