JP3764052B2 - Heat shield for furnace repair - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat shielding apparatus that shields a portion that needs repair from heat when hot repairing a part of various industrial furnaces and prevents a temperature drop in a portion that does not require repair as much as possible.
[0002]
[Prior art]
Industrial furnaces, including blast furnaces, heating furnaces, soaking furnaces, heat treatment furnaces and their attached equipment such as flue and hot air tubes used in various industrial fields including the steel industry, include refractories and ceramics. Insulating material such as fiber is lined. However, since these heat insulation materials are partially damaged during use, it is necessary to repair the damaged portion.
[0003]
For example, when repairing a hot air pipe for blowing hot air from the hot air furnace to the blast furnace, the hot air valve is removed and the outer wall is opened, and the opening is closed with a heat-resistant curtain to produce the width radiant heat from the inside of the pipe. While defending, a pipe connected to the castable spraying device was inserted between the insulation curtains, and repaired by spraying the castable.
[0004]
However, in such a conventional method, it is dangerous because an operator cannot avoid radiant heat completely, and the blowing direction of the castable is limited to the hot air valve side. It was difficult to carry out safe and complete repairs, such as when the castables did not reach enough when they were far from the station.
[0005]
On the other hand, it is conceivable to cool and repair the hot air tube, but in order to cool the hot air tube, it is necessary to stop the furnace for a long period of time, and there is a problem that the loss is extremely large in terms of operation and energy.
[0006]
[Problems to be solved by the invention]
In view of such conventional circumstances, the present invention shields a repaired part from radiant heat to the extent that a safe repair work can be performed when hot repairing a part of various industrial furnaces, and at the same time, a temperature other than the repaired part. An object of the present invention is to provide a furnace-shielding heat shield device that can suppress the decrease, complete repair work in a short time, and return to normal operation.
[0007]
[Means for Solving the Problems]
To achieve the above object, the heat shield device for use between an industrial furnace heat repair of the present invention provides is both when injecting air into the bag was sewn heat cross, particle size distribution supply ceramic particles of 1~48μm Then, the bag is clogged with ceramic particles and inflated to form a heat shielding wall at the repair location.
[0008]
In the heat shielding apparatus for repairing a furnace according to the present invention, the ceramic particles are made of at least one selected from powders of refractory clay such as bentonite and kaolin, alumina, silica, and mullite particles , and the heat resistance thereof is 1000. It is preferable that the temperature is at least ° C.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The heat shield device of the present invention is a safe heat shield by installing a heat shield wall in which a bag made of heat-resistant cloth is inflated by injecting air like a balloon near a place requiring repair, and shielding the repair place from radiant heat. It enables repair work between the two. At the same time, if there is a lot of air leakage from the bag made of heat-resistant cloth, the amount of injected air required to inflate the bag will increase, and the temperature outside the repaired area will be lowered more than necessary. By introducing and dispersing, the bag is clogged to some extent, air leakage is suppressed, and the amount of injected air is suppressed.
[0010]
Specifically, a bag having a size slightly larger than the inner diameter of the inner wall of the furnace is sewn using a heat-resistant cloth, and the bag is folded and placed in the furnace. Couplers and hoses for injecting air are connected to the bag, air is injected from the compressor, and ceramic particles are supplied simultaneously or in advance to expand the bag while clogging it. Hot air and radiant heat are blocked by the heat shielding wall formed by inflating the bag in this manner, and the damaged part in the furnace is hot repaired without stopping the operation of the industrial furnace in this state.
[0011]
Therefore, the heat-resistant cloth bag used in the present invention does not need to be provided with a rubber layer or the like on both sides or one side of the bag in order to prevent air leakage, so that excellent heat resistance can be maintained. In addition, the heat shielding wall that clogs the bag with ceramic particles can inflate the bag with less air because there is little air leakage, and it can prevent an unnecessary decrease in the furnace temperature due to the leaked air. it can. Here, the terms “industrial furnace” and “furnace” are used to include auxiliary equipment such as flues and hot air tubes.
[0012]
By using the heat shielding device of the present invention, it is possible to easily construct a bag-like heat shielding wall with a small amount of air injection, and not only can perform hot repair work safely and efficiently, but also heat after the repair is completed. It is possible to squeeze the shielding wall and remove it easily. Therefore, coupled with the fact that there is little decrease in temperature other than at the repair location, it is possible to complete the repair work in a short time and return to the normal furnace operation state, which is extremely advantageous in terms of furnace operation.
[0013]
The heat-resistant cloth constituting the bag in the present invention is not particularly limited as long as it is made of fire-resistant fiber, but heat-resistant cloth made of silica or alumina can be generally used. Although one heat-resistant cloth may be used, it is usually preferable to use a plurality of heat-resistant cloths. Further, the ceramic particles only have to have a heat resistance of 1000 ° C. or higher. For example, refractory clay powder such as bentonite or kaolin, or particles of alumina, silica, mullite, or the like can be used.
[0014]
The particle size distribution of the ceramic particles used depends on the opening of the bag made of heat-resistant cloth, but it is usually possible to cause clogging and expand the bag if it is within the range of 0.1 to 100 μm, The range of 1 to 48 μm is more preferable. The supply amount of the ceramic particles, the use of ceramic particles of particle size of the range, generally it is possible to inflate the bag heat cross If 50 g / m ² approximately, preferably at least 80~150g The supply amount is about / m ² .
[0015]
The expansion of a bag made of a refractory cloth is mainly affected by the amount of air supplied to the bag and the particle size distribution of the ceramic particles. Therefore, it is desirable to select ceramic particles having an appropriate particle size distribution for a bag made of refractory cloth. For example, when three types of ceramic particles having the particle size distribution shown in FIG. 2 are used, the differential pressure between the pressure in the expanded bag and the atmospheric pressure is as shown in FIG. As can be seen from this result, by using ceramic particles having a particle size distribution of about 1 to 48 μm, leakage of air from the bag can be suppressed and the bag can be sufficiently inflated with a small amount of air.
[0016]
The ceramic particles are generally supplied at the same time as the air is injected. However, the ceramic particles can be supplied in advance in the bag, or the supply of the ceramic particles is started after the bag is expanded to some extent by the air injection. You can also. Moreover, after the bag is sufficiently expanded, the supply amount of ceramic particles can be reduced or the supply can be stopped.
[0017]
【Example】
Three sheets of satin weave silica cloth (REFRASIL C100-48: 0.66 mm thickness made by HITOCO) are laminated, and one piece of plain cloth alumina cloth (NEXTEL # 14 made by 3M company: thickness 0.36 mm) is further laminated. Thus, a substantially spherical bag having an outer diameter of about 2 m was sewn.
[0018]
As shown in FIG. 1, the bag 1 was placed in a hot air tube 2 of a hot stove, a coupler 3a for injecting air was attached, and the hose 3b was connected to the compressor 4. Thereafter, without supplying ceramic particles at all, only air is injected from the compressor 4 into the bag 1, and while the amount of air injection is adjusted by the valve 5 and the flow meter 6, the swelling of the bag 1 is observed and the pressure gauge 7 The differential pressure from the atmospheric pressure was measured.
[0019]
As a result, in the state where the ceramic particles were not supplied, the bag 1 was almost fully inflated for the first time when air of 40 m ³ / min was injected, and the differential pressure at that time was 38 mmH ₂ O. However, since there is a lot of air leakage from the bag 1, the bag 1 cannot be kept inflated unless air is continuously injected at the air injection amount, and the bag 1 is not sufficiently expanded as the air injection amount is reduced. Thus, the bag 1 hardly swelled at an air injection rate of 10 m ³ / min or less.
[0020]
Next, about 1 kg (corresponding to 80 g / m ² ) of refractory clay powder having a particle size distribution of 1 to 48 μm was previously placed in the bag 1 and air was injected into the bag 1, and the air injection amount was only 20 m ^3. Sufficient expansion was obtained even at 1 min / min, and the differential pressure at that time was 45 mmH ₂ O. Moreover, once the bag 1 was fully expanded, the same expanded state could be maintained even if the air injection amount was reduced to 10 m ³ / min.
[0021]
The inflated bag 1 (heat shielding wall) shields radiant heat from the hot stove so that an operator can enter the repair location 2a of the hot air tube 2 and perform hot repairs. When the inside of the collected bag 1 was observed visually and with a microscope after the above experiment was completed, it was observed that refractory clay particles had entered the eyes of the cloth and were clogged.
[0022]
【The invention's effect】
According to the present invention, when hot repairing a part of an industrial furnace, it is possible to easily shield the repaired part from radiant heat without stopping the entire furnace, and at the same time to perform a safe repairing work. It is possible to suppress a decrease in temperature other than the above, complete the repair work in a short time, and return to normal operation.
[Brief description of the drawings]
FIG. 1 is a schematic side view of a heat repair apparatus for repairing a furnace according to the present invention, partially cut away.
FIG. 2 is a graph showing the particle size distribution of various ceramic particles.
3 is a graph showing the relationship between the differential pressure between the pressure inside the bag and atmospheric pressure and the supply air pressure for each ceramic particle in FIG. 2;
[Explanation of symbols]
1 Bag 2 Hot air pipe 2a Repair location 4 Compressor

Claims (2)

A heat shield device for use in hot repair of industrial furnaces, both when injecting air into the bag was sewn heat cross, and particle size distribution supply ceramic particles 1～48Myuemu, clogging the bag with ceramic particles A heat shielding device for repairing a furnace, which is expanded and then used as a heat shielding wall at a repair location.   The ceramic particles are made of at least one selected from powders of refractory clay such as bentonite and kaolin, alumina, silica, and mullite particles, and the heat resistance is 1000 ° C or more. A heat shielding apparatus for repairing a furnace according to 1.

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