JP6176056B2 - Inorganic fiber insulation block and furnace with the same installed on the inner wall - Google Patents

Description

  The present invention relates to a heat insulating material block made of an inorganic fiber molded body, and in particular, an inorganic fiber heat insulating material block suitable for use as a heat insulating member for a furnace wall or a ceiling in a high-temperature furnace such as a heating furnace or a blast furnace and a construction thereof. Related to the furnace. In detail, it is related with the heat insulating material block which consists of a compression inorganic fiber molded object which compressed the inorganic fiber mat laminated body and maintained this compression state by the shape-retaining means. Moreover, this invention relates to the furnace which constructed this inorganic fibrous heat insulating material block.

  Inorganic fiber insulation using inorganic fiber aggregates made of non-woven fabric by laminating inorganic fibers as an inorganic fiber insulation block covering the walls of various refractory furnaces such as high-temperature furnaces such as heating furnaces and heat treatment furnaces in the steel industry The material is used. Above all, a needling-processed inorganic fiber aggregate (needle blanket) is often used because of its characteristics such as lightness, easy processability, thermal shock resistance, wind erosion resistance, and low thermal conductivity.

  In JP 2011-226771 A, inorganic fiber needle blankets are laminated and an inorganic fiber heat insulating material block maintained in a compressed state is applied to a furnace wall or ceiling of a high-temperature furnace without any gaps, and then the compression is released. A lining method is described in which the heat insulating material blocks are closely abutted using the repulsive force and restoring force in the stacking direction of the needle blanket itself.

  As described above, the inorganic fibrous heat insulating material block has advantages such as light weight and excellent heat insulating properties, but corrosion due to scale or alkali gas generated from the furnace is a problem. In particular, in the heating furnace of the steel industry, iron oxide and inorganic fibers in the furnace generate a low-melting-point compound, which causes erosion and brittleness from that point, and has a problem of shortening the lining life.

In JP-A-11-212357, an alumina sol or a mixed sol of alumina sol and silica sol is applied to one surface in the blanket lamination direction to form a coating layer by applying 55 to 300 g / m ^{2 in} terms of solid content, and then dried (0031 paragraph). An inorganic fiber block with improved corrosion resistance is described.

Japanese Patent Application Laid-Open No. 2011-32119, paragraph 0029 describes that a coating layer having a thickness of 2 mm is formed by spraying a FeO-resistant coating material on the surface of an inorganic fiber block in a furnace. When this coating layer is heated in the furnace, CaO.6Al ₂ O ₃ is generated.

Japanese Patent Laid-Open No. 2011-208344 discloses an inorganic fiber molded body obtained by impregnating an inorganic fiber needle blanket with an inorganic sol and then drying, and is a lightweight inorganic material having a bulk density of 0.08 to 0.20 g / cm ^3. A fiber molded body is described.

JP 2011-226771 A JP-A-11-212357 JP 2011-32119 A JP 2011-208344 A

  In the inorganic fiber block described in Patent Documents 2 and 3, the coating layer or the coating layer formed by coating or spraying is easy to peel from the inorganic fiber molded body. For example, there is a problem that the coating layer is peeled off due to thermal shock or mechanical shock, and the inorganic fibers are exposed. Furthermore, in patent document 3, since it constructed by spraying with a spray gun after constructing an inorganic fiber molded object to a furnace wall, there also existed a problem that construction work became complicated.

  In the inorganic fibrous heat insulating material block described in Patent Document 4, since the inorganic sol is impregnated in the entire needle blanket and dried, when applied to the compressed inorganic fibrous heat insulating block, the flexibility of the heat insulating material block And the repulsive force becomes low.

  The present invention solves the above-mentioned conventional problems, improves the corrosion resistance such as FeO resistance, and has excellent repulsive force (restorability), and the inorganic fiber heat insulating material block is implemented. The purpose is to provide an improved furnace.

  The inorganic fiber heat insulating block of the present invention is an inorganic fiber heat insulating block used for lining the heated surface in the furnace, and a laminated body of needle blankets or mats of inorganic fibers is compressed in the laminating direction and maintained. In the inorganic fibrous heat insulating material block held in a compressed state by the forming means, the heating surface side of the inorganic fibrous heat insulating material block disposed toward the furnace is impregnated with the oxide precursor containing liquid, And the impregnation part which is an undried state is formed, the range of the impregnation part from the heating surface is 3 to 60 mm, and the amount of water in the impregnation part is 50% of moisture with respect to 100 parts by mass of the impregnation part inorganic fiber. -700 parts by mass, and the oxide precursor-containing liquid is impregnated in the impregnated part so that the amount of oxide after firing is 2 to 50 parts by mass with respect to 100 parts by mass of the impregnated inorganic fiber When done In the portion of the inorganic fiber heat insulating block exceeding 60 mm in the depth direction from the heating surface side in the furnace to the depth direction on the furnace wall surface, the oxide deposition amount after firing is 100 parts by weight of the impregnated inorganic fiber. It is impregnated so that it may become 1 mass part or less.

  It is preferable that the range from the heating surface of the impregnation part impregnated with the oxide precursor-containing liquid is 5 to 60 mm.

  It is preferable that the water content in the impregnation part impregnated with the oxide precursor-containing liquid is 50 to 700 parts by mass of water with respect to 100 parts by mass of the inorganic fibers.

The oxide precursor-containing liquid preferably includes a component that generates Al ₂ O ₃ by firing and a component that generates CaO by firing.

The oxide precursor-containing liquid, _Al 2 _{O 3,} based on caused by firing, the mass ratio _Al 2 _O 3 / CaO and CaO produced by firing is preferably 30 to 300.

  It is preferable that the oxide precursor-containing liquid is impregnated so that the oxide deposition amount after firing is 2 to 50% by mass.

  The oxide precursor-containing liquid may be colored, whereby the impregnated portion may be colored.

  The furnace according to the present invention is such that the inorganic fiber heat insulating material block according to the present invention is lined in such a form that the shape retaining by the shape retaining means is released.

  In the inorganic fibrous heat insulating material block of the present invention, the heated surface side of the compressed inorganic fiber molded body obtained by compressing the laminated body of the needle blanket or mat of inorganic fibers is impregnated with the oxide precursor containing liquid. Therefore, the corrosion resistance (particularly FeO resistance) of the inorganic fibrous heat insulating material block is improved. In addition, since the oxide precursor-containing liquid is impregnated only on the heating surface side and the impregnated oxide precursor-containing liquid is in an undried state, the repulsion (restorability) of the inorganic fibrous heat insulating material block is achieved. Are better. Therefore, after the inorganic fiber heat insulating material block is installed in the furnace, when the shape retention by the shape retaining means is released, the adjacent inorganic fiber heat insulating material blocks come into close contact with each other, and the heat insulating property becomes remarkably high. .

It is a perspective view of the inorganic fibrous heat insulating material block which concerns on embodiment. It is a one part enlarged view of the inorganic fibrous heat insulating material block of FIG. It is a perspective view of the inorganic fibrous heat insulating material block which concerns on another embodiment.

  The inorganic fibrous heat insulating material block according to the present invention is preferably a block heat insulating material in which a needle blanket or mat laminate is compressed in the laminating direction, and is maintained in a compressed state by a fixing means. The liquid material is impregnated in the depth direction on the wall surface side until construction. The impregnation depth is at least 3 mm and 60 mm or less, preferably 30 mm or more and 50 mm or less in the depth direction from the furnace heating surface side to the furnace wall surface side.

Since the inorganic fibrous heat insulating material block of the present invention is obtained by compressing a needle blanket or a mat, it has a repulsive force after releasing a compressive force and can be lined. The bulk density after compression of the needle blanket or mat is preferably 0.3 g / cm ³ or less, exceeding the bulk density of the needle blanket or mat to be used. If the density is too high, the thermal shock resistance during high-temperature use or rapid cooling / rapid temperature rise may be reduced.

  As a shape-retaining means for maintaining the compressed state, a pressurizing surface abutting portion covering at least a part of each of the pressurizing surfaces of the compressed inorganic fiber molded body, and the heating surface abutting portion, and a fibrous heat insulating material block are provided. A heating surface protection portion that covers at least a part of the heating surface that is heated in a state where the lining is applied in the furnace, and a boundary portion between the pressing surface contact portion and the heating surface protection portion is the pressure surface A means for fixing with a shape-retaining plate and a binding band covering a corner of the unit block formed by the heating surface is preferable. After maintaining the compressed state with such shape-retaining means, a method may be selected in which the block state is used for construction and the compressed state is maintained by the repulsive force between the heat insulating members after cutting the band.

  It is desirable that a cue portion is provided on the heating surface protection portion of the shape retaining plate.

  The shape-retaining plate may be partially cut out to such an extent that a hole is formed on the heating surface side or side surface side, or the shape-retaining property is not impaired. Thereby, since it becomes easy to impregnate the inorganic fiber of the back side of a shape-retaining board with an oxide precursor containing liquid, the impregnation state of an inorganic fibrous heat insulating material block can be made more uniform.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

[First Embodiment]
FIG. 1 is a perspective view of an inorganic fibrous heat insulating material block according to the first embodiment, and FIG. 2 is an enlarged side view of a part thereof.

  This inorganic fibrous heat insulating material block 1 includes a folded body 3 of an inorganic fiber molded body 2, shape-retaining plates 4 and 4 superimposed on the pressure surfaces (upper and lower surfaces in FIG. 1) of the folded body 3, and The shape retaining plates 4 and 4 and the binding band 5 for securing the folded body 3 are provided. The folded body 3 has a substantially rectangular parallelepiped shape in which a band-like mat-like inorganic fiber molded body 2 having a predetermined width is alternately folded back and stacked, and has a surface on one end in the stacking direction (vertical direction in FIG. The shape retaining plates 4 are overlapped on the other end surface.

  The side of the folded body 3 on which the shape-retaining plates 4 and 4 do not overlap, the region facing the one side (the left side in FIG. 1) where the folded portion of the inorganic fiber molded body 2 is present, is an oxide precursor. The impregnation portion 6 is impregnated with the contained liquid.

  The inorganic fiber molded body 2 is preferably a needle blanket obtained by subjecting an inorganic fiber mat to needling processing, but may be a mat not subjected to needling processing. The preferred configuration of the needle blanket and the composition of the oxide precursor-containing liquid impregnated in the impregnation portion 6 will be described later.

  The shape-retaining plate 4 is made of a material such as synthetic resin, paper, and plywood having strength and rigidity for sandwiching the folded body 3 from both sides. The dimension of the shape retaining plate 4 is preferably the same as the pressing surface of the folded body 3. The binding band 5 is wound around the shape retaining plates 4 and 4 and the folded body 3 between them. As the binding band 5, a synthetic resin tape such as polypropylene is suitable.

  The foldable body 3 sandwiched between the shape retaining plates 4 and 4 is compressed and compressed in the laminating direction so as to be 50 to 90%, particularly 60 to 80% of the thickness of the non-pressurized state, and then the binding band. 5 is wound and the shape is kept in this compressed state. Therefore, in this embodiment, the shape-retaining means is constituted by the shape-retaining plates 4 and 4 and the binding band 5.

  The dimension a in the depth direction of the inorganic fibrous heat insulating material block 1 after being bound and held by the binding band 5 is 100 to 400 m, particularly 200 to 300 mm, and the dimension b in the direction perpendicular thereto is 100 to 400 mm, particularly 200 to 300 mm. The dimension c in the stacking direction is preferably about 100 to 400 mm, particularly about 200 to 300 mm.

  In the inorganic fiber heat insulating material block 1 according to this embodiment, the inorganic fiber molded body 2 is folded before impregnating the oxide precursor-containing liquid to form a folded body 3, and the shape retaining plates 4 and 4 are stacked and compressed. After the binding band 5 is wound, the impregnated portion 6 is formed by impregnating the oxide precursor-containing liquid. However, the impregnation treatment may be performed before the folding body 3 is compressed. Alternatively, the inorganic fiber molded body 2 may be impregnated before being folded into a zigzag shape, and then folded. However, in order to obtain a prescribed impregnation thickness d, it is preferable to perform the impregnation treatment after folding and compressing.

  This impregnation part 6 is provided in the whole surface of the inorganic fiber heat insulating material block heating surface which faces the inside of the furnace in a state where the inorganic fiber heat insulating material block 1 is installed in the furnace. The impregnation part 6 is preferably formed by immersing the folded body 3 in the oxide precursor-containing liquid, and then suctioning and removing excess water as necessary. However, the impregnation part 6 may be formed by spraying or the like. After the impregnation part 6 is formed in this manner, the impregnation part 6 is not dried and is not dried.

  By adjusting the depth when the folded body 3 is immersed in the oxide precursor-containing liquid, the thickness d of the impregnated portion 6 is preferably 3 to 60 mm, particularly preferably 30 to 50 mm. If d is smaller than 3 mm, the effect of improving the corrosion resistance is lowered, and there is a problem that the impregnated portion 6 is easily peeled off after firing. When it exceeds 60 mm, there is a possibility that the restoring property of the folded body 3 is lowered.

  When the binding band 5 of the inorganic fibrous heat insulating material block 1 is cut, the folded body 3 is restored so as to increase the thickness in the stacking direction (vertical direction in FIG. 1) due to its elasticity. In this inorganic fibrous heat insulating material block 1, since the oxide precursor adhering to the impregnation part 6 is in an undried state, the restoring force of the folded body 3 is strong. Therefore, when a plurality of inorganic fibrous heat insulating material blocks 1 are arranged along the inner wall of the furnace and then the binding band 5 is cut, the adjacent inorganic fibrous heat insulating material blocks 1 closely adhere to each other, and a gap is generated between them. It is prevented.

  When lining the inorganic fiber heat insulating material block 1 in a furnace, the heating surface of the inorganic fiber heat insulating material block 1, that is, the surface having the impregnation portion 6 (the left side surface in FIG. 1) faces the inside of the furnace, and the opposite side. It arrange | positions so that a back surface (right side surface of FIG. 1) may face furnace bodies, such as a furnace wall and a furnace ceiling part.

  When each inorganic fibrous heat insulating material block 1 is lined by the so-called checkered method, its heating surface is set so that the lamination direction (that is, the restoring direction) of adjacent inorganic fibrous heat insulating material blocks 1 does not coincide with each other as in Patent Document 1. After being arranged along the furnace inner surface in a posture rotated by 90 ° as viewed from, the binding band 5 is cut, and the binding band 5 and the shape retaining plate 4 are removed. The lining may be performed by a soldering method other than the checkered method.

  It is preferable that the water content in the impregnation part 6 is 50 to 700 parts by mass with respect to 100 parts by mass of the inorganic fibers. When the water content is excessively small, the machine fiber molded bodies are fixed to each other due to the binder effect, and the repulsive force is reduced. On the other hand, when the amount is excessively large, the liquid may leak from the inorganic fiber, or the impregnation depth may be excessive, which may reduce the repulsive force.

  The amount of the oxide precursor attached to 100 parts by mass of the inorganic fiber in the impregnated part 6 is preferably 2 to 50 parts by mass, more preferably 5 to 30 parts by mass, and most preferably 10 in terms of the amount of oxide added after firing. ˜25 parts by mass. If the amount of attachment is small, the desired scale resistance may not be obtained. On the other hand, if the amount is too large, deterioration of the thermal shrinkage rate, thermal shock resistance and mechanical shock resistance may be reduced.

  The repulsive force portion 7 is a portion other than the impregnated portion 6 of the inorganic fiber molded body 2. The amount of oxide after firing of the repulsive force portion 7 is 1 part by mass or less (including 0 (zero)), preferably 0.5 parts by mass or less, with respect to 100 parts by mass of the inorganic fiber of the impregnated part 6. Preferably it is 0.2 mass part or less. It is preferable that the amount of oxide attached after firing of the repulsive force portion 7 is in the above range because the repulsive force of the inorganic fiber needle blanket can be maintained.

  In the present invention, the oxide precursor of the oxide precursor-containing liquid is a substance that generates calcium oxide by firing, specifically, calcium hydroxide, chloride, acetate, milk oxide, or glass oxide. It is preferable to contain. In addition, the oxide precursor preferably contains a substance that generates aluminum oxide by firing, specifically, aluminum hydroxide, chloride, vinegar oxide, milk oxide, glass oxide, particularly alumina sol.

As the oxide precursor, those containing each of the above substances so that the weight ratio of CaO: Al ₂ O ₃ is 1:99 to 10:90, particularly 5:95 to 9:91, by firing are preferable. If it this blending ratio, when it is heated in a furnace, a high _CaO · _2Al 2 O 3 resistant to scale resistance, CaO · _6Al alumina-calcia-based refractory oxide, such as 2 _{O 3} is produced.

  The oxide component concentration in the oxide precursor-containing liquid is preferably 2 to 30% by mass, particularly 5 to 20% by mass. If this concentration is too low, the adhesion amount (attachment amount) of the oxide precursor component to the inorganic fiber molded body may be low. On the other hand, if the concentration is too high, the viscosity of the oxide precursor-containing liquid becomes high, which may make it difficult to impregnate.

  The oxide precursor-containing liquid may be a sol, a slurry, or a solution. As the dispersion medium or solvent, water, an organic solvent such as alcohol, or a mixture thereof, preferably water is used. Moreover, polymer components, such as polyvinyl alcohol, may contain. A dispersion stabilizer may be added in order to increase the stability of the compound in the sol, slurry, or solution. Examples of the dispersion stabilizer include acetic acid, lactic acid, hydrochloric acid, nitric acid, sulfuric acid and the like.

  A coloring agent may be blended in the oxide precursor-containing liquid. By coloring, the thickness d of the impregnated part can be visually observed. The coloring color is preferably black or blue. A water-soluble ink or the like can be used as the colorant.

  After impregnating the oxide precursor-containing liquid, excess liquid may be removed by suction or compression as necessary. In order to remove excess liquid by suction, it is preferable to attach an attachment covering the impregnation portion 6 and suck a suction port provided in the attachment.

  In order to prevent drying, the inorganic fibrous heat insulating material block 1 having the impregnated portion 6 in an undried state is preferably packed and stored and transported by vacuum packing or shrink packing.

  Next, the inorganic fiber needle blanket preferably used in the present invention will be described. The needle blanket described in Patent Document 4 is preferably substantially free of fibers having a fiber diameter of 3 μm or less and subjected to a needling treatment. In addition, the wind erosion resistance of an inorganic fibrous heat insulating material block can be improved by using this needle blanket.

{Inorganic fiber}
The inorganic fiber is not particularly limited, and examples thereof include silica, alumina / silica, zirconia containing these, spinel, titania and the like alone, or composite fibers. Particularly preferred are heat resistance, fiber strength (toughness), and safety. From the viewpoint of properties, it is an alumina / silica fiber, particularly a polycrystalline alumina / silica fiber.

  The composition ratio (mass ratio) of alumina / silica fiber in the alumina / silica fiber is preferably in the range of 65 to 98/35 to 2 called mullite composition or high alumina composition, more preferably 70 to 95/30 to 5, particularly preferably in the range of 70 to 74/30 to 26.

  In the present invention, it is preferred that the inorganic fiber is 80% by mass or more, preferably 90% by mass or more, and particularly preferably the total amount thereof is a polycrystalline alumina / silica fiber having the mullite composition.

  This inorganic fiber is preferably substantially free of fibers having a fiber diameter of 3 μm or less. Here, “substantially free of fibers having a fiber diameter of 3 μm or less” means that the fibers having a fiber diameter of 3 μm or less is 0.1 mass% or less of the total fiber weight.

  The average fiber diameter of the inorganic fibers is preferably 5 to 7 μm. If the average fiber diameter of the inorganic fiber is too thick, the repulsive force and toughness of the fiber assembly will be lost, and if it is too thin, the amount of dust generation floating in the air will increase, and there is a high probability that fibers with a fiber diameter of 3 μm or less will be contained. Become.

  The inorganic fiber aggregate having the above-mentioned preferred average fiber diameter and substantially free of fibers having a fiber diameter of 3 μm or less is used in the production of inorganic fiber aggregates by the sol-gel method, and the control of the spinning solution viscosity, the spinning nozzle It can be obtained by controlling the air flow used for the yarn and controlling the drying of the drawn yarn.

{Needle mark density}
The needle mark density of the needle blanket is preferably 2 to 200 strokes / cm ² , particularly ² to 150 strokes / cm ² , particularly 2 to 100 strokes / cm ² , and particularly preferably ² to 50 strokes / cm ² . If the needle mark density is too low, the uniformity of the thickness of the inorganic fiber molded article is reduced and the thermal shock resistance is lowered. If the needle mark density is too high, the fiber is damaged and easily scattered after firing. There is a fear.

{Bulk density, surface density, thickness}
The bulk density of the needle blanket is preferably 0.05~0.20g / cm ^3, more preferably 0.08~0.15g / cm ^3. If the bulk density is too low, only a fragile inorganic fiber molded body can be obtained. If the bulk density is too high, the bulk density of the inorganic fiber molded body increases and the repulsive force is lost, resulting in a molded body with low toughness.

The surface density of the needle blanket is preferably 1000 to 4000 g / m ² , particularly 1500 to 3800 g / m ² , particularly 2000 to 3600 g / m ² . If the surface density of the inorganic fiber aggregate is too small, the amount of fibers is small, and only a very thin molded body can be obtained, and the usefulness as an inorganic fiber molded body for heat insulation is reduced. When the amount is too large, it becomes difficult to control the thickness by the needling process.

  The thickness of the needle blanket is preferably about 2 to 35 mm.

  As described in Patent Document 4, the needle blanket includes a step of obtaining an aggregate of inorganic fiber precursors by a sol-gel method, and a step of performing a needling treatment on the obtained aggregate of inorganic fiber precursors. The inorganic fiber precursor aggregate that has been subjected to the needling process is fired to obtain an inorganic fiber aggregate.

[Second Embodiment]
In the first embodiment, the folded body 3 in which the inorganic fiber molded body 2 is alternately folded in a zigzag manner is used. However, the inorganic fiber molded body 2 is simply cut into the size a × b. A single plate may be laminated. FIG. 3 is a perspective view of such an inorganic fibrous heat insulating material block 1 ′.

  In addition, in the inorganic fiber heat insulating material block 1 ′ in FIG. 3, all overlapping surfaces of the single plates of the inorganic fiber molded body 2 are exposed to the heating surface. On the other hand, in the inorganic fibrous heat insulating material block 1 of FIG. 1, only half of the folded overlapping surfaces are exposed to the heating surface. Corrosion due to scale often occurs from joints, and the life of the heat insulating member can be extended by reducing the number of joints. Therefore, the inorganic fibrous heat insulating material block 1 of FIG.

[Other embodiments]
In the said embodiment, although the flat thing was used as the shape-retaining board 4, the standing piece (around the side edge of the folding body 3 from the side edge of a flat plate (pressurization surface contact part) like patent document 1 ( You may make it protect the corner | angular edge of the folding body 3 using the L-shaped plate-shaped body which has a heating surface contact part. Moreover, you may provide the clue part for an operator to handle to the standing piece which overlaps with the heating surface of an inorganic fiber heat insulating material block like patent document 1. FIG. A locking member for locking the inorganic fibrous heat insulating material block 1 to the furnace wall may be provided on the back side of the folded body 3 (right side surface in FIG. 1).

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[Example 1]
Polycrystalline alumina / silica-based fibers containing 72% by mass of alumina and 28% by mass of silica having an average fiber diameter of 5.5 μm and substantially free of fibers having a fiber diameter of 3 μm or less are accumulated and needling. Needle blanket (trade name: Mitsubishi resin MAFTEC MLS, thickness 25 mm, bulk density 96 kg / m ³ ) is processed into a width of 300 mm × length of 4800 mm, folded alternately at a length of 300 mm, and stacked into 16 layers and folded. It was set to 3. A 300 mm × 300 mm × 320 mm polypropylene shape-retaining plate 4 is stacked on the surfaces of both ends of the folded body 3 in the laminating direction, compressed in the laminating direction, fixed with a binding band 5 after compression, and 300 mm × 300 mm × 300 mm inorganic fiber A molded body was obtained.

As an oxide precursor-containing liquid, calcium acetate monohydrate is added to an alumina sol solution so that the oxide mass ratio after firing is 91.6: 8.4, and the solid content concentration in terms of oxide is 7. A liquid adjusted to 0% was prepared. After impregnating this liquid 4L from the heating surface side to d = 50 mm, an attachment is attached to the heating surface and the liquid is sucked from the heating surface with a suction force of 3.0 m ³ / min. Produced.

  In this inorganic fibrous heat insulating material block 1, the scale resistance, the repulsive force, the moisture content in the impregnation part 6 and the amount of attachment were measured by the methods described later. The results are shown in Table 1. The impregnation amount of the oxide precursor-containing liquid in the repulsive force portion 7 was 0 (zero).

[Example 2]
In Example 1, the inorganic fibrous heat insulating material block was created similarly except having set the suction | attraction force of the liquid to 10 m < ³ > / min. Table 1 shows the measurement results such as scale resistance.

[Example 3]
In Example 1, the inorganic fibrous heat insulating material block was created similarly except having set the suction | attraction force of the liquid to 0.5 m < ³ > / min. Table 1 shows the measurement results such as scale resistance.

[Comparative Example 1]
An inorganic fibrous heat insulating material block was prepared in the same manner as in Example 1 except that the oxide precursor liquid material was not impregnated. Table 1 shows the measurement results such as scale resistance.

[Comparative Example 2]
In Example 1, the inorganic fiber heat insulation block was similarly produced except having dried the inorganic fiber heat insulation block at 150 degreeC for 24 hours. Table 1 shows the measurement results such as scale resistance.

[Comparative Example 3]
In Example 1, the inorganic fiber heat insulation block was similarly produced except having dried the inorganic fiber heat insulation block at 120 degreeC for 12 hours. Table 1 shows the measurement results such as scale resistance.

[Reference Example 1]
In Example 1, an inorganic fibrous heat insulating material block was manufactured in the same manner as in Example 1 except that 6.0 L of the impregnating liquid was impregnated, but the liquid leaked from the heating surface side. In addition, the amount of attachment at this time was 51 mass%, and the impregnation part thickness d was 70 mm.

[Example 4]
In Example 1, the oxide precursor liquid substance was inorganic in the same manner as in Example 1 except that the alumina sol solution and magnesium acetate tetrahydrate were adjusted so that the oxide mass ratio after firing was 72:28. A fibrous insulation block was prepared. Table 1 shows the measurement results such as scale resistance.

≪Measurement method of characteristics≫
[Scale resistance]
It was installed in a hot rolling furnace in the steel industry and used for 6 months at an operating temperature of 1350 ° C., and the state of erosion due to scale was confirmed.

[Repulsiveness in the stacking direction]
The binding band 5 of the inorganic fibrous block was cut and stretched in the laminating direction by a restoring force, and the dimension in the laminating direction after stretching was measured. It can be said that the resilience is excellent when the length of the inorganic fiber heat insulation block after cutting the binding band is + 20% or more than the length before cutting (that is, when the length is 360 mm or more).

[Water content]
The inorganic fibrous heat insulating material block was cut every 10 mm with a cut surface parallel to the heating surface, and dried at 150 ° C. for 2 hours. The mass before and after drying was measured, and the water content of the impregnated part was determined. This water content is the mass of moisture relative to 100 parts by mass of the inorganic fibers.

[Adhesion amount]
From the inorganic fibrous heat insulating material block, cut the portion that is not impregnated with the oxide precursor-containing liquid, and obtain the surface specific gravity per one piece of the inorganic fiber needle blanket constituting the inorganic fibrous heat insulating material block. The average value was defined as the surface specific gravity r ₁ before attachment. After firing the inorganic fibrous heat insulating material block impregnated with the oxide precursor-containing liquid at 1250 ° C. for 2 hours, the impregnated portion 6 was cut out and the surface specific gravity r ₂ was measured by the same method. Using r ₁ and r ₂ , the amount of attachment was determined by the calculation formula (r ₂ −r ₁ ) / r ₁ . This amount of deposition represents the amount of oxide deposition (% by mass) in the impregnation portion 6.

About the surface specific gravity (repulsive force part 7) of the part which is not impregnated with the oxide precursor-containing liquid, the needle blanket used in the example (trade name: Mitsubishi Resin MAFTEC MLS, thickness 25 mm, bulk density 96 kg / m ³ ). The surface specific gravity is calculated by the following formula.
Surface specific gravity = raw fabric weight / area = raw fabric weight / density × thickness

As shown in Table 1, the inorganic fibrous thermal insulation blocks of Examples 1 to 3 impregnated with an appropriate amount of an Al ₂ O ₃ —CaO-based impregnating agent and made into an undried state after impregnation have excellent resilience and are resistant to scale. Excellent in properties. In Example 4, since the impregnating agent is Al ₂ O ₃ —MgO, the resilience is excellent, but the scale resistance is slightly inferior. Comparative Examples 2 and 3, which were dried after impregnation with an Al ₂ O ₃ —CaO-based impregnating agent, were excellent in scale resistance but low in resilience. In Comparative Example 1, nothing was impregnated and the resilience was high, but the scale resistance was poor.

1, 1 'Inorganic fiber heat insulating material block 2 Inorganic fiber molded body 3 Folded body 4 Shape retention board 5 Binding band 6 Impregnation part 7 Repulsion part

Claims (5)

An inorganic fiber insulation block used for lining construction of the heated surface in the furnace,
In an inorganic fiber heat insulating material block in which a laminate of inorganic fiber needle blankets or mats is compressed in the laminating direction and held in a compressed state by a shape-retaining means,
An impregnation portion that is impregnated with the oxide precursor-containing liquid and is in an undried state is formed on the heating surface side of the inorganic fibrous heat insulating material block that is disposed toward the furnace,
The range from the heating surface of the impregnation part is 3 to 60 mm,
The amount of water in the impregnation part is 50 to 700 parts by weight of water with respect to 100 parts by weight of the impregnation part inorganic fiber.
The oxide precursor-containing liquid is impregnated in the impregnated portion so that the amount of oxide after baking is 2 to 50 parts by mass with respect to 100 parts by mass of the impregnated inorganic fiber,
In the portion of the inorganic fiber heat insulating material block in the depth direction exceeding 60 mm in the depth direction from the furnace heating surface side to the furnace wall surface side, the oxide deposition amount after firing is 100 parts by mass of the impregnated inorganic fiber. An inorganic fibrous heat insulating material block impregnated so as to be 1 part by mass or less. _2. The inorganic fibrous heat insulating material block according to claim 1, wherein the oxide precursor-containing liquid includes a component that generates Al ₂ O ₃ by firing and a component that generates CaO by firing. Composition after firing of the inorganic fiber heat insulating material block impregnation unit, _Al 2 _{O 3} and _Al 2 _{O 3} of inorganic fibers caused by firing, the mass ratio _Al 2 _O 3 / CaO and CaO produced by firing 30 to 300 The inorganic fibrous heat insulating material block according to claim 2, wherein   The inorganic fibrous heat insulating material block according to any one of claims 1 to 3, wherein the oxide precursor-containing liquid is colored, whereby the impregnated portion is colored.   A furnace in which the inorganic fiber heat insulating material block according to any one of claims 1 to 4 is lined in a form in which shape retention by the shape retaining means is released.

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