JP6274374B1 - Method for constructing skid pipe and its heat insulating protective member - Google Patents

Abstract

There are provided a skid pipe with a heat insulating protection member that can sufficiently prevent the occurrence of a gap at the upper end of the heat insulating protective member, and a method for constructing the heat insulating protective member. A plurality of ring-shaped needle blankets 10 are wound around the skid pipe 1 and pressed by the pressing plate 20 to form the first compressed layer L-1. The second compressed layer L-2 and the third compressed layer L-3 are formed on the upper side and are pressed by the pressing plate 20 respectively. After loading the ring-shaped needle blanket 10 between the fireproof coating 3, the presser plate 20 is pulled out. The compression rate of the third compression layer L-3 is made larger than those of the first and second compression layers L-1 and L-2.

Description

  The present invention relates to a skid pipe in a heating furnace and a construction method for the heat insulating protective member.

  As a protection member for a skid pipe in a heating furnace of the steel industry, an inorganic fiber aggregate or an inorganic fiber molded body having high thermal shock properties is used (Patent Documents 1 and 2).

  Patent Document 1 describes that a skid pipe is covered with a ring-shaped heat insulating material made of ceramic fiber. In FIG. 8 and paragraph 0002 of Patent Document 1, it is described that a ring-shaped heat insulating material partly cut is attached to a skid pipe. Patent Document 1 does not describe the construction after the insulating material is compressed.

  In Patent Document 2, a plurality of halved ceramic fiber refractory materials are stacked, then compressed, placed on the outer periphery of the heating furnace support pipe while maintaining the compressed state, and decompressed to restore the ceramic fiber refractory material A method for constructing a heat insulating material is described. According to this construction method, a phenomenon in which a gap is generated on the upper end side of the support pipe due to the refractory material contraction is suppressed.

JP 2004-43918 A JP 2010-151284 A

  The present invention relates to a skid pipe in which a heat insulating protective member made of an inorganic fiber molded body surrounds the skid pipe, a skid pipe with a heat insulating protective member that can prevent the occurrence of a gap at the upper end of the heat insulating protective member, and its heat insulating protection It aims at providing the construction method of a member, and makes the following a summary.

[1] In a method for constructing a heat insulating protection member below a fireproof coating of a skid pipe having a fireproof coating on the upper part, a plurality of inorganic fiber ring needle blankets are externally fitted to the skid pipe and stacked. Next, the process of forming the compression layer by pressing the stack from above with a press plate is repeated a plurality of times to form the first to nth (n is an integer of 2 or more) compression layers, The ring-shaped needle blanket is externally fitted between the upper compressed layer and the lower end surface of the fireproof coating, and then the presser plate is removed to restore the stack, and the ring-shaped needle blanket is attached to the fireproof coating. It is a construction method of the heat insulation protective member pressed against the lower end surface of the above, and when the bulk density of the compressed layer is evaluated by dividing the bulk density into an upper part, a middle part and a lower part into three parts, the bulk density in the upper part is Parts and construction method of the heat-insulating protection member of the skid pipe, characterized in that higher than the bulk density at the lower.

[2] The insulation protection member for a skid pipe according to [1], wherein the bulk density of the upper compression layer is 1.1 to 3.0 times the bulk density of the middle and lower compression layers. Construction method.

[3] The construction method of a heat insulating protection member for a skid pipe according to [1] or [2], wherein the bulk density in the middle part is higher than the bulk density in the lower part.

[4] In any one of [1] to [3], the bulk density of the upper compressed layer is 0.10 g / cm ³ or more and 0.20 g / cm ³ or less. Construction method of members.

[5] In any one of [1] to [4], the ring-shaped needle blanket made of inorganic fibers has a residual surface pressure ratio after a cycle test under the conditions described below of 10% or more. Construction method for heat insulation and protection members for pipes.
Conditions: After compressing the ring-shaped needle blanket after firing for 12 hours at 1400 ° C. to GBD (bulk density) = 0.195 using a tensile compression tester, the upper and lower plates are compressed from GBD = 0.20 to 0.24. This was repeated 100 times. At that time, the open side pressure value at the first GBD = 0.20 and the open side pressure value at the 100th GBD = 0.24 were measured. The remaining surface pressure ratio (%) as an index is obtained.
Residual surface pressure ratio = 100th opening side pressure / first opening side pressure × 100

[6] In any one of [1] to [5], the inorganic fiber ring needle blanket has a heat shrinkage rate of 1% in the width direction, the longitudinal direction, and the thickness direction after firing at 1400 ° C. for 12 hours. The construction method of the heat insulation protection member of a skid pipe characterized by the following.

[7] In any one of [1] to [6], a radial slit is provided in the ring-shaped needle blanket, and the ring-shaped needle blanket is fitted on the skid pipe by opening the slit. A method for constructing a heat insulating protection member for a skid pipe characterized by the above.

[8] The construction method for a heat insulating and protecting member for a skid pipe according to [7], wherein the slits of the ring-shaped needle blanket are shifted in the circumferential direction so as not to overlap each other.

[9] In any one of [1] to [8], an anchor fitting insertion portion is provided in the skid pipe, and an anchor fitting for preventing the holding plate from moving upward is inserted into the anchor fitting insertion. The construction method of the heat insulation protection member of a skid pipe characterized by locking to a part and preventing the upward movement of a presser plate.

[10] In [9], the anchor metal fitting has a pin protruding vertically, and the pin is pierced through a ring-shaped needle blanket that overlaps the presser plate. Construction method of members.

[11] In any one of [1] to [10], after that, a blanket having an oxide precursor-containing liquid attached in an undried state is wound around the outer periphery of the ring-shaped needle blanket, and the oxide precursor The method for constructing a heat insulating protective member for a skid pipe, wherein the liquid contains a component that produces an alumina-calcia composition containing aluminum oxide and calcium oxide by firing.

[12] In a skid pipe with a heat insulating protective member provided with a heat insulating protective member on the lower side of the fire resistant coating of the skid pipe having an upper portion, the heat insulating protective member is a compressed state in which the heat insulating protective member is externally fitted to the skid pipe. A ring-shaped needle blanket stack, wherein the top ring-shaped needle blanket is pressed against the fireproof coating by the repulsive force of the stack. When evaluated by dividing the upper part into the upper part, the middle part and the lower part in the height direction, the bulk density of the ring-shaped needle blanket in the upper part is higher than the bulk density of the ring-shaped needle blanket in the middle part and the lower part. A skid pipe with a thermal protection member.

  In the skid post in which the heat insulation protection member is constructed by the method for constructing the heat insulation protection member of the present invention, the ring-shaped needle blanket disposed on the upper side of the uppermost nth compression layer has the first to nth compression. It is pressed by the repulsive force of the ring needle blanket of the layer and pressed against the lower end surface of the fireproof coating. In particular, in the present invention, when the bulk density of the compressed layer is evaluated by dividing the bulk density into an upper part, a middle part, and a lower part in the height direction, the bulk density in the upper part is higher than the bulk density in the middle part and the lower part. In particular, when the ring-shaped needle blanket of the first to nth compression layers is applied with the same ring-shaped needle blanket, the ring-shaped needle blanket of the upper compression layer is most strongly compressed, so Shows a strong repulsive force on the coating. This repulsive force is maintained even during operation of the furnace, and prevents a gap between the fireproof coating and the uppermost ring-shaped needle blanket, which is generated by vibration generated during slab transportation, over a long period of time. In the present invention, by using an inorganic fiber ring-shaped needle blanket, the repulsive force is increased and the gap can be effectively prevented from being formed.

  In one embodiment of the present invention, the outer side of the laminated compressed layer is coated with a blanket to which the oxide precursor-containing liquid is attached in an undried state, and thus the coated blanket is converted into a scale through a separate baking step. In contrast, the blanket containing an alumina and calcia composition containing aluminum oxide and calcium oxide having high durability is obtained. In the unlikely event of erosion due to the scale, if the laminated compressed layer is not eroded, the blanket can be easily cut and recoated, so that the repairability is excellent and the cost is low. And by using an alumina fiber needle mat, since it is lightweight, it is excellent in workability and excellent in wind erosion and thermal shock.

It is a perspective view which shows the construction method of the heat insulation protection member which concerns on embodiment. It is a perspective view which shows the construction method of the heat insulation protection member which concerns on embodiment. It is a perspective view which shows the construction method of the heat insulation protection member which concerns on embodiment. 4a is an enlarged view of a part of FIG. 3, and FIG. 4b is a longitudinal sectional view of the vicinity of the anchor fitting of FIG. 4a. It is a perspective view which shows the construction method of the heat insulation protection member which concerns on embodiment. It is a perspective view which shows the construction method of the heat insulation protection member which concerns on embodiment. It is a perspective view which shows the construction method of the heat insulation protection member which concerns on embodiment. FIG. 8A is a perspective view showing a construction method of the heat insulation protection member according to the embodiment, and FIG. 8B is a cross-sectional view taken along the line VIIIb-VIIIb of FIG. 8A. It is a top view which shows another shape of a holding plate. It is sectional drawing which shows the connection structure of a presser plate.

  Hereinafter, embodiments will be described with reference to FIGS.

  As shown in FIG. 1, the skid pipe 1 on which the heat insulation protective member is constructed is a pipe shape made of heat-resistant steel, and is erected from the hearth G of the heat treatment furnace. A skid beam 2 is installed so as to be supported by a plurality of skid pipes 1. A fireproof coating 3 made of fireproof castable is applied to the upper part of the skid pipe 1. In the present invention, a heat insulating protective member is applied to the underside of the fireproof coating 3 in the skid pipe 1.

  The skid pipe 1 is provided with a plurality of anchor fitting insertion portions 4 at intervals in the height direction. The anchor fitting insertion portion 4 has a U-shaped horizontal cross section, and as shown in FIG. 4b, a clearance C (FIG. 4b) into which the anchor fitting is inserted from above is formed between the outer peripheral surface of the skid pipe 1. Yes.

Since the horizontal section of the skid pipe 1 may not be a perfect circle, it is preferable that the outer periphery of the skid pipe 1 is covered with the base layer 5 (see FIG. 8b) prior to the construction of the heat insulating protection member. By covering this base layer 5, the horizontal cross-sectional shape of the outer peripheral surface becomes a substantially circular shape, the adhesion between the outer peripheral surface and the laminated compressed layer is increased, and a higher heat insulating effect can be exhibited. The underlayer 5 is made of inorganic fibers, castable refractories, or the like.

  In the present invention, a plurality of annular materials (hereinafter referred to as ring-shaped needle blankets) 10 made of a needle blanket of inorganic fibers (alumina fibers in this embodiment) are attached to the lower part of the skid pipe 1. It is preferable to use an inorganic fiber needle blanket having a high repulsive force as the annular material. The ring-shaped needle blanket 10 is provided with a slit 11 (FIG. 2) in the radial direction, and the ring-shaped needle blanket 10 is fitted on the skid pipe 1 so as to open the slit 11. In the ring-shaped needle blankets 10 adjacent to each other in the vertical direction, it is preferable that the directions of the ring-shaped needle blankets 10 are different one by one so that the slits 11 do not overlap in order to prevent a gap from being formed in the outer fitting portion.

  After the required number of ring-shaped needle blankets 10 are stacked, the presser plate 20 is disposed above the uppermost ring-shaped needle blanket 10 as shown in FIG.

  In this embodiment, the presser plate 20 is configured by abutting two presser plate halves 21 and 22 together.

  The presser plate halves 21 and 22 have substantially semicircular curved side portions 21a and 22a on opposite sides. Both sides of the curved side portions 21a and 22a are arm-like portions 21b and 22b. Each arm-like portion 21b, 22b is provided with a small hole 24 for inserting a bolt. The presser plate 20 is configured by overlapping the distal ends of the arm portions 21b and 22b so that the curved sides 21a and 22a face each other and fastening them with bolts 23 (FIGS. 3 and 4a). The presser plate 20 is formed with a circular opening 25 (FIGS. 3, 4a, 4b).

  Each of the curved side portions 21a and 22a is provided with a U-shaped cutout portion 26. Each notch 26 is arranged to face the diameter direction of the opening 25. This notch 26 is for passing the pin 33 of the anchor fitting 30.

  An L-shaped cutout 27 is provided on the rear sides of the presser plate halves 21 and 22 (sides opposite to the curved side portions 21a and 22a). A belt is hung on the notch 27 as described later. Further, in the vicinity of the rear sides of the presser plate halves 21 and 22, a small hole 28 is provided for passing the string-like member or hanging a hand or a tool when the presser plate halves 21 and 22 are pulled out.

  The presser plate halves 21 and 22 are approached from both sides with the skid pipe 1 interposed therebetween, and are joined by bolts 23 to form the presser plate 20 that is externally fitted to the skid pipe 1. The stacked body of the ring-shaped needle blanket 10 is pressed from above and compressed.

  The compression method is not particularly limited, and examples include a compression method using a belt. Among these, a compression method using a belt is preferable because it is the lowest in cost and easy. When performing compression using a belt, the presser plate 20 has an L-shaped cutout 27 to easily apply the compression belt and to remove the belt after compression, particularly the presser plate 20 has a low position. Preferred in some cases.

  In a state where the stack of the ring-shaped needle blanket 10 is pressed by the presser plate 20, the anchor fitting 30 is inserted into the anchor fitting insertion portion 4 and fixed with the wedge 35.

  As shown in FIGS. 3, 4 a, and 4 b, the anchor metal fitting 30 is a heat-resistant steel member having a vertical piece 31 and a horizontal piece 32 and having an inverted L shape in side view. The vertical piece 31 is inserted into the clearance C between the anchor fitting insertion part 4 and the outer peripheral surface of the skid pipe 1. The horizontal piece 32 is provided with needle-like pins 33 protruding upward and downward. The pin 33 is inserted into the ring-shaped needle blanket 10 pressed by the presser plate 20 through the notch portion 26. Then, a portion near the notch 26 of the presser plate 20 that presses the ring-shaped needle blanket 10 is pressed from above with the horizontal piece 32.

  Thereafter, a wedge 35 is driven between the vertical piece 31 and the skid pipe 1 to fix the presser plate 20 to the skid pipe 1. As a result, the first-stage presser plate 20 is fixed to the skid pipe 1, and a first compression layer L-1 in which a plurality of ring-shaped needle blankets 10 are compressed is formed on the lower side thereof.

Thereafter, as shown in FIG. 5, a required number of ring-shaped needle blankets 10 are stacked on the upper side of the first-stage presser plate 20 so as to surround the skid pipe 1. An upward pin 33 of the anchor fitting 30 is pierced through the ring-shaped needle blanket 10. Then, the second stage of the pressing plate 20 is fitted on the skid pipe 1, shrink press stack of ring-shaped needle blanket 10, the second stage of the pressing plate 20 to the skid pipe 1 by the anchor 30 Fix it. Thereby, the 2nd compression layer L-2 is formed.

A required number of ring-shaped needle blankets 10 are stacked on the upper side of the second-stage presser plate 20 so as to surround the skid pipe 1. An upward pin 33 of the anchor fitting 30 is pierced through the ring-shaped needle blanket 10. Next, the third-stage presser plate 20 is fitted onto the skid pipe 1, the stack of the ring-shaped needle blanket 10 is pressed and contracted, and the third- stage presser plate 20 is fixed to the skid pipe 1 by the anchor fitting 30. Thereby, the third compressed layer L-3 is formed.

In this way, as shown in FIG. 5, the skid pipe 1 is surrounded by the three-stage compression layers L-1, L-2, and L-3. When the uppermost third compression layer L-3 is formed, the pressing force pressing the ring-shaped needle blanket stack with the third-stage presser plate 20 is used when the first and second compression layers are formed. Make it larger than the pressing force. Thereby, the uppermost third compressed layer L-3 is more strongly compressed than the first and second compressed layers L-1 and L-2.

  As shown in FIG. 5, there is a gap between the uppermost third compression layer L-3 and the fireproof coating 3 made of fireproof castable. Therefore, as shown in FIG. 6, a ring-shaped needle blanket 10 is stacked on this gap. Arrange. Also in this case, the pin 33 is pierced through the ring-shaped needle blanket 10 on the upper side of the uppermost presser plate 20.

  After that, as shown in FIG. 6, the bolts 23 of the presser plates 20 are removed, and the presser plate halves 21 and 22 are pulled out in the direction of arrow F in FIG. The ring-shaped needle blanket 10 that overlaps the presser plate 20 is not pulled out by being dragged by the presser plate 20 because the pin 33 is pierced and fixed. When pulling out the holding plate halves 21 and 22, it is preferable to hang a string-like body, fingers or tools on the small holes 28 of the holding plate halves 21 and 22.

  When each presser plate 20 is pulled out, the ring-shaped needle blanket 10 disposed on the upper side of the uppermost third compression layer L-3 becomes the ring-shaped needles of the first to third compression layers L-1 to L-3. It is pressed by the repulsive force of the blanket 10 and pressed against the lower end surface of the fireproof coating 3. In particular, in this embodiment, the same ring-shaped needle blanket 10 is used in the first compression layer L-1 to the third compression layer L-3, and the ring-shaped needle blanket of the uppermost third compression layer L-3. 10 was compressed most strongly, that is, the bulk density of the uppermost third compression layer L-3 was higher than the bulk density of the first compression layer L-1 and the second compression layer L-2. The ring-shaped needle blanket 10 immediately below the 3 is strongly pressed against the fireproof coating 3. This repulsive force is maintained even during operation of the furnace, and prevents a gap between the fireproof coating 3 and the uppermost ring-shaped needle blanket 10 generated by vibrations generated during slab transportation for a long period of time.

  In the above embodiment, the presser plate 20 is composed of two presser plate halves 21 and 22, but the presser plate 20 is composed of three presser plate halves, four presser plate quadrants, or five. You may be set as the above small board. When the presser plate is composed of three or more small plates, the ring-shaped needle blanket 10 is more difficult to wrinkle when the small plate is extracted, and the resistance force when extracting the presser plate is smaller than in the case of two.

FIG. 9 is a plan view of a presser plate 20 ′ constituted by three presser plate halves 21 ′.
Each presser plate half body 21 ′ has a fan shape, and the cutout portion 26 is provided on the inner peripheral edge, and the L-shaped cutout portion 27 is provided on the outer peripheral edge. The small hole 28 is provided in the vicinity of the outer peripheral edge.

  An annular presser plate 20 ′ is configured by overlapping both sides (radial sides) of the presser plate half halves 21 ′ and connecting them with bolts 23. Using this presser plate 20 ', the ring-shaped needle blanket 10 can be constructed in the same manner as in the above embodiment.

  In the embodiment described above, in the overlapping portion of the presser plate halves 21 and 22 or the presser plate half halves 21 ', stepped portions are formed on one upper surface and the other lower surface. As shown in FIG. 10, the protruding piece 210 is fixed to the upper surface of one holding plate half 21 by welding or the like, and the protruding piece 210 is extended to the upper surface of the other holding plate half 22, and the bolt 23 The presser plate halves 21 and 22 may be connected to each other by passing the screw through the projecting piece 210 and the presser plate half 22 and tightening the nuts. The presser plate half halves 21 'may be connected in the same manner. In FIG. 10, the overhanging piece 210 is provided on the upper surface side of the presser plate halves 21 and 22, but may be provided on the lower surface side.

  After pulling out the presser plate 20 (or 20 ') as described above, the blanket 40 in which the oxide precursor-containing liquid is attached to the outer periphery of each ring-shaped needle blanket 10 in an undried state as shown in FIGS. 8a and 8b. To finish the construction. The blanket 40 to which the oxide precursor-containing liquid is attached in an undried state becomes an alumina-calcia composition-containing blanket containing aluminum oxide and calcium oxide through a separate baking step.

  By winding the blanket 40, the fired alumina-calcia-based composition-containing blanket can receive the wind that originally travels in parallel to the laminated compression layer, so that the skid pipe according to the present invention Hot air intrusion into the protective member can be efficiently prevented.

  The blanket 40 needs to be fixed with an adhesive or a tape as required. As the adhesive, a heat-resistant curing agent is preferably used. Since the blanket 40 is made of a different material from the amorphous refractory, there is a difference in shrinkage due to the material. As a result, the blanket 40 cannot adhere well to the irregular refractory. There may be space between them. However, since the laminate 10 of the blanket 40 and the ring-shaped needle blanket is made of the same material, there is no difference in shrinkage due to the material, and the oxide precursor-containing liquid of the blanket 40 is laminated of the ring-shaped needle blanket. The oxide precursor on the surface of the laminate 10 of the blanket 40 and the ring needle blanket becomes an oxide when the oxide precursor is easily soaked into the surface of the body 10 and converted into an oxide during firing. Since the oxide functions as an adhesive between the blanket 40 and the ring needle blanket laminate 10, the adhesion of the blanket 40 to the ring needle blanket laminate 10 is remarkably improved. The blanket 40 may be wound only by one layer, or may be wound by two or more layers. Preferably, the blanket 40 wraps the joint between the fireproof coating and the ring-shaped needle blanket with the blanket 40 so that the calcined alumina / calcia composition-containing blanket suppresses heat from entering the gap. It is preferable in that it can be performed.

Moreover, even if the outermost surface of the calcined alumina / calcia composition-containing blanket is subjected to scale erosion due to the two or more layers of the blanket 40 being wound, the inner side of the blanket containing the alumina / calcia composition Since the surface of the blanket containing the alumina and calcia composition not subjected to scale erosion appears, scale can be prevented for a long time. When the alumina-calcia-based composition containing blanket surface receiving no scale erosion inside is exhausted, the remaining alumina-calcia-based composition containing blanket surface easily with a cutter Yasu click Ray path over Can be removed. Since it can withstand scale erosion for at least one year, maintenance frequency can be greatly reduced. And since it can give scale resistance again by winding the blanket 40 again, it is excellent in low cost and repairability. Since the laminated body 10 of the ring-shaped needle blanket inside the blanket 40 is not eroded by the scale, it can be used for a long period of time by periodically replacing the blanket 40.

  In the said embodiment, lamination | stacking and compression of the ring-shaped needle blanket 10 are performed in 3 times, and the 1st-3rd compression layers L-1-L-3 are formed, but the height of the skid pipe 1 is formed. Depending on, you may carry out 2 times or 4 times or more.

  When the bulk density of the compressed layer is evaluated by dividing the bulk density into the upper part, the middle part, and the lower part into three equal parts, the bulk density in the upper part is higher than the bulk density in the middle part and the lower part. The bulk density of the compressed layer is 1.1 to 3.0 times, preferably 1.2 to 2.0 times, more preferably 1.3 to 1.times the bulk density of the middle and lower compressed layers. 7 times. By setting the bulk density of the upper compression layer within the above range with respect to the bulk density of the middle and lower compression layers, the slab can be transported during operation of the furnace without the ring-shaped needle blanket constituting the compression layer being crushed. This is preferable in that the generation of a gap between the fireproof coating and the uppermost ring-shaped needle blanket that is generated by vibrations that are sometimes generated is suppressed.

  Furthermore, the bulk density in the middle part is higher than the bulk density in the lower part, and the ring-shaped needle blanket constituting the compression layer is not crushed, and the fireproof coating generated by vibrations generated during slab transportation during operation of the furnace And the uppermost ring-shaped needle blanket are preferable in that generation of a gap is suppressed.

The bulk density of the upper compressed layer is usually 0.10 g / cm ³ or more and 0.20 g / cm ³ or less, preferably 0.12 g / cm ³ or more and 0.18 g / cm ³ or less, more preferably 0. .14g / cm ³ or more 0.16g / cm ³ or less.

The bulk density of the middle compression layer is not particularly limited as long as it is lower than the bulk density of the upper compression layer, but is usually 0.10 g / cm ³ or more and 0.20 g / cm ³ or less, preferably 0.13 g / cm 2. cm ³ or more and 0.16 g / cm ³ or less.

The bulk density of the lower compression layer is not particularly limited as long as it is lower than the bulk density of the upper compression layer, and it is preferable that the bulk density in the middle portion is higher than the bulk density in the lower portion. Usually less than 0.10 g / cm ³ or more 0.20 g / cm ^3, preferably not more than 0.13 g / cm ³ or more 0.16 g / cm ^3.

  The compressibility of the ring-shaped needle blanket 10 of the upper compression layer (the third compression layer L-3 and the ring-shaped needle blanket 10 disposed on the upper side of the third compression layer L-3 in the above embodiment) [[ (Original thickness) − (Thickness after compression)] × 100 / [Original thickness]) is not limited as long as the bulk density relationship is satisfied, but is usually 10% or more, particularly 12%. In particular, it is preferably 13% or more, usually 30% or less, particularly 25% or less, particularly 20% or less. The compression ratio of the middle and lower compression layers (the first and second compression layers L-1 and L-2 in the above embodiment), which is a compression layer other than the upper portion, is 5% or more, particularly 7% or more, particularly 8% or more. Therefore, it is preferably 20% or less, particularly 18% or less, particularly 15% or less. The compression ratio of the upper part is preferably 1.1 times or more, particularly 1.5 times or more, and 4 times or less, particularly 3 times or less of the compression ratio of the middle and lower compression layers. Furthermore, it is more preferable that the compression ratio of the middle part is higher than the compression ratio of the lower part.

The bulk density before compression of one ring-shaped needle blanket 10 is not particular limitation, usually 0.05 g / cm ³ or higher, preferably 0.06 g / cm ³ or more, particularly preferably 0.08 g / cm ³ or more, usually 0.18 g / cm ³ or less, preferably 0.16 g / cm ³ or less, particularly preferably 0.14 g / cm ³ or less.

  The thickness (thickness before compression) of one ring-shaped needle blanket 10 is not particularly limited, but is usually 10 mm or more, particularly 12 mm or more, and preferably 26 mm or less, particularly 30 mm or less.

  The number of the ring-shaped needle blankets 10 constituting one compressed layer is 15 or more, particularly 20 or more, and preferably 80 or less, particularly 60 or less.

When the height from the hearth G to the lower end of the fireproof coating 3 is H, and the height of the gap formed between the uppermost presser plate 20 and the coating 3 in the state of FIG.
h / H is preferably 0.005 or more, particularly 0.01 or more, and 0.05 or less, particularly 0.035 or less.

  Height before releasing the compression force of the upper compression layer (in the above embodiment, the third compression layer L-3 and the ring-shaped needle blanket 10 disposed above the third compression layer L-3) 5 is preferably 25% or more, particularly 30% or more, and 50% or less, particularly 48% or less of the height H.

  The radial dimension of the ring-shaped needle blanket 10 (that is, a value that is ½ of the difference between the outer diameter (diameter) and the inner diameter (diameter)) is 3% or more, particularly 5% or more of the diameter of the skid pipe 1, % Or less, particularly preferably 80% or less.

In the ring-shaped needle blanket 10, there is no particular limitation, but the remaining surface pressure ratio after the cycle test under the conditions described below is 10% or more, preferably 12% or more, more preferably 15% or more.
Conditions: After the ring-shaped needle blanket 10 fired at 1400 ° C. for 12 hours is compressed to GBD (bulk density) = 0.195 g / cm ³ using a tensile compression tester, the upper and lower plates are moved from GBD = 0.20 g / cm ^3. The compression to 0.24 g / cm ³ was repeated 100 times. At that time, the open side pressure value at the first GBD = 0.20 g / cm ³ and the open side pressure value at the 100th GBD = 0.24 g / cm ³ were measured. The residual surface pressure ratio (%), which is an index of the degree of deterioration of the rear surface pressure, was obtained.
Residual surface pressure ratio = 100th opening side pressure / 1st opening side pressure)

  When the residual surface pressure ratio is in the above range, the repulsive force of the ring-shaped needle blanket is maintained even during operation of the furnace, and the gap between the ring-shaped needle blankets can be prevented over a long period of time. This is preferable in that a gap between the fireproof coating and the uppermost ring-shaped needle blanket can be prevented over a long period of time.

Further, in the ring-shaped needle blanket 10, the heating line shrinkage in the width direction, the longitudinal direction and the thickness direction after firing (1400 ° C., 12 hours) is not particularly limited, but a method based on JIS R3311 (details below) In any case, it is preferably 1% or less, more preferably 0.5% or less. Since the heating line shrinkage ratio is in the above range in the width direction, the longitudinal direction, and the thickness direction, the ring-shaped needle blanket is preferable in that it has excellent high temperature dimensional stability and is difficult to reduce the thickness.
Conditions: A sample is cut into a length of about 150 mm and a length of about 100 mm to form a test piece. A test piece is marked by embedding a white silver wire in a rectangular shape of about 120 mm × about 60 mm. Hold in air heated to a temperature of 1400 ° C. for 12 hours. Heating shrinkage is calculated by the following formula.

Here, l _{0 is} the length (mm) before firing between the test piece marks, and l _{1 is} the length (mm) after firing between the test piece marks. The heating line shrinkage rate is the average of the three points measured for the length of three points on one test piece.

[Material for ring-shaped needle blanket 10 etc.]
Next, suitable materials for the blanket 40 to which the ring-shaped needle blanket 10 and the oxide precursor-containing liquid are attached will be described.

  The ring-shaped needle blanket 10 is not particularly limited as long as it is an inorganic fiber blanket, but is preferably an inorganic fiber needle blanket described later.

The blanket 40 to which the oxide precursor-containing liquid is attached in an undried state is a component that generates an alumina calcia composition containing aluminum oxide and calcium oxide by firing the inorganic oxide blanket on an inorganic fiber blanket. Is included. Preferably, the needle blanket is composed of an inorganic fiber needle blanket, and at least a part of the needle blanket is provided with an impregnated portion to which an oxide precursor-containing liquid is attached in an undried state, and the water content of the impregnated portion is 50 to 400 parts by mass with respect to 100 parts by mass of the inorganic fiber, and 50 to 400 parts by mass of the water content of the entire heat insulating protective member with respect to 100 parts by mass of the inorganic fiber of the entire heat insulating protective member. The product precursor-containing liquid is an alumina-calcia composition containing aluminum oxide (Al ₂ O ₃ ) and calcium oxide (CaO) by firing (Al ₂ O ₃ and CaO may be a simple substance or a double oxide. In the impregnated part, the oxide precursor-containing liquid is contained in an oxide equivalent amount with respect to 100 parts by mass of the inorganic fibers in the impregnated part. It adheres so that it may become 2-50 mass parts, and the molar ratio (Al / Ca) of Al and Ca in the said whole impregnation part (the whole of an inorganic fiber and a deposit | attachment) is 10-330.

Especially, it is preferable that the inorganic fiber blanket of the blanket 40 is of the same quality as the inorganic fiber blanket of the ring-shaped needle blanket 10.
The blanket 40 has a bulk density of usually about 0.10 to 0.75 g / cm ³ , preferably about 0.15 to 0.60 g / cm ³ , particularly preferably about 0.20 to 0.45 g / cm ³ . is there.

[Needle blanket]
An inorganic fiber needle blanket (hereinafter, simply referred to as “blanket” or “needle blanket” in some cases) used for the heat insulating protective member of the present invention will be described.

  The needle blanket preferably has a fiber aggregate of inorganic fibers substantially free of fibers having a fiber diameter of 3 μm or less that has been subjected to a needling treatment. By using such a needle blanket, the wind erosion resistance of the heat insulating protective member for skid posts of the present invention can be enhanced.

<Inorganic fiber>
The inorganic fiber constituting the needle blanket is not particularly limited, and examples thereof include silica, alumina / silica, zirconia containing these, spinel, titania and calcia alone, or a composite fiber. From the viewpoint of fiber strength (toughness) and safety, 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. In addition, the molar ratio of Ca to Al (Ca / Al) in the inorganic fiber is preferably 0.03 or less, and it is particularly preferable that the inorganic fiber does not contain Ca.

  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.

<Manufacturing method of needle blanket>
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 to control the spinning solution viscosity in the production of the inorganic fiber aggregate by the sol-gel method. It can be obtained by controlling the air flow used for the spinning nozzle, controlling the drying of the drawn yarn, and controlling the needling.

  The needle blanket includes a step of obtaining an aggregate of inorganic fiber precursors by a sol-gel method as described in a conventionally known method, for example, JP-A-2014-5173, and an aggregate of the obtained inorganic fiber precursors It is manufactured through a step of subjecting the body to a needling treatment and a firing step of firing the aggregate of the inorganic fiber precursor subjected to the needling treatment to form an inorganic fiber aggregate.

<Needle mark density, bulk density and thickness of needle blanket>
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 needle blanket thickness will be reduced and the thermal shock resistance will be reduced. If it is too high, the fibers will be damaged and may be easily scattered after firing. .

The bulk density of the needle blanket is preferably 50 to 200 kg / m ³ (0.05 to 0.2 g / cm ³ ), and 80 to 150 kg / m ³ (0.08 to 0.15 g / cm ³ ). More preferably. If the bulk density is too low, a fragile inorganic fiber molded body is obtained. If the bulk density is too high, the mass of the inorganic fiber molded body increases and the repulsive force is lost, resulting in a molded body having low toughness.

The surface density of the needle blanket is preferably 500 to 4000 g / m ² , particularly 600 to 3800 g / m ² , particularly 1000 to 3500 g / m ² . If the surface density of the needle blanket 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. If the surface density is too large, the amount of fibers is too large. This makes it difficult to control the thickness by the needling process.

  The thickness of the needle blanket is preferably about 2 to 35 mm. As will be described later, the thickness of the needle blanket is 3 mm or more, preferably 10 mm or more from the viewpoint of securing the impregnation depth of the oxide precursor-containing liquid. It is preferably 3 mm or more, particularly 10 mm or more.

  In the present invention, the inorganic fiber needle blanket is formed into a plate shape. However, the plate-shaped needle blanket may be formed into a roll shape at the time of handling.

[Oxide precursor-containing liquid]
The oxide precursor-containing liquid impregnated in the needle blanket is a component that produces an alumina-calcia composition containing aluminum oxide (Al ₂ O ₃ ) and calcium oxide (CaO) by firing as an oxide precursor. Including. In this alumina-calcia composition, Al ₂ O ₃ and CaO may be a simple substance or a double oxide of Al ₂ O ₃ and CaO. The mixed oxide of Al ₂ O ₃ and _CaO, although _{CaO · Al 2 O 3, CaO} · 2Al 2 O 3, CaO · 6Al 2 O 3 and the like, but is not limited thereto.

  The presence form of the oxide in the fired product when only the oxide precursor-containing liquid is dried and fired may be any of the following (i) to (v).

(I) Al ₂ O ₃ simple substance and CaO simple substance (ii) Al ₂ O ₃ simple substance and CaO simple substance and double oxide (iii) Al ₂ O ₃ simple substance and double oxide (iv) CaO simple substance and double oxide (v) Double oxide only

  The oxide precursor-containing liquid includes at least a component containing Ca and a component containing Al. Specific examples of the component containing Ca include calcium hydroxide, chloride, acetate, lactate, nitrate, carbonate, and the like. Only 1 type of these may be contained in the oxide precursor containing liquid, and 2 or more types may be contained. Among these, calcium acetate, hydroxide, or carbonate is preferably water and carbon dioxide, and is preferable from the viewpoint of not deteriorating metal members in the furnace, steel plates, and the like.

  The component containing Ca may be dissolved in the oxide precursor-containing liquid, or may be sol or dispersed. The Ca-containing component is dissolved or uniformly dispersed in the oxide precursor-containing liquid, so that the oxide precursor is uniformly coated on the entire surface of each inorganic fiber constituting the needle blanket. In addition, it is preferable in that it can be easily impregnated into the inorganic fiber. When the Ca-containing component is precipitated in the oxide precursor-containing liquid, the surface of the inorganic fiber cannot be uniformly coated, and a portion that is not coated on the fiber surface is generated, and there is a possibility that erosion due to the scale may occur from there. Therefore, the effect of improving the scale resistance cannot be sufficiently exhibited.

  Specific examples of the component containing Al include aluminum hydroxide, chloride, acetate, lactate, nitrate, carbonate and the like. Only 1 type of these may be contained in the oxide precursor containing liquid, and 2 or more types may be contained. Especially, it is preferable that it is an acetate, a hydroxide, or carbonate of aluminum that the components which generate | occur | produce at the time of baking are water and a carbon dioxide, and the point which does not deteriorate the metal member, a steel plate, etc. in a furnace.

  The component containing Al may be dissolved in the oxide precursor-containing liquid, sol form, or dispersed form. Since the component containing Al is dissolved or uniformly dispersed in the oxide precursor-containing liquid, the oxide precursor is uniformly coated on the entire surface of each inorganic fiber constituting the needle blanket. In addition, it is preferable in that it can be easily impregnated into the inorganic fiber. When the Al-containing component precipitates in the oxide precursor-containing liquid, the surface of the inorganic fiber cannot be uniformly coated, and a portion that cannot be coated on the fiber surface is generated, and there is a possibility that erosion due to scale may occur from there. Therefore, the effect of improving the scale resistance cannot be sufficiently exhibited.

  Preferably, it is an alumina sol using acetic acid as a dispersant, and this is excellent in that the components generated during firing are water and carbon dioxide. For the same reason, an alumina sol using lactic acid as a dispersant can also be used. In this case, the heat shrinkage rate of the heat insulating protective member for skid post is the heat insulating protective member for skid post using alumina sol using acetic acid as a dispersing agent. It tends to be higher than

  The component which produces | generates CaO by baking used when said alumina sol is used has preferable the acetate of calcium. By mixing the acetate, it is possible to suppress a decrease in the dispersibility of the alumina sol and to suppress an increase in the viscosity of the oxide precursor-containing liquid. When the viscosity of the oxide precursor-containing liquid is within an appropriate range, it is easy to impregnate and control the amount of adhesion. If the viscosity of the oxide precursor-containing liquid is excessively high, impregnation with inorganic fibers becomes difficult, which is not preferable.

  As the oxide precursor-containing liquid, an aqueous calcium acetate solution in which alumina sol is dispersed is preferable.

  The oxide precursor-containing liquid preferably contains the above-described component containing Al and the component containing Ca so that the molar ratio of Al to Ca (Al / Ca) is 4 or more and 100 or less, More preferably, it is 6 or more and 36 or less, and particularly preferably 9 or more and 13 or less. When the Al / Ca ratio is within this range, when heated in the furnace, the calcium component can be appropriately diffused and the inorganic fibers and scale can be prevented from reacting. Further, since a calcium oxide-based oxide having high scale resistance is generated, the effect of improving the scale resistance is excellent.

The oxide precursor concentration of the oxide precursor-containing liquid (the total content of the component that produces Al ₂ O ₃ by firing and the component that produces CaO by firing) is 2 to 2 in terms of solid concentration in terms of oxide. 30% by mass, particularly 5 to 10% by mass is preferred. If the oxide precursor concentration of the oxide precursor-containing liquid is too low, the amount of oxide precursor component attached to the needle blanket (attachment amount) may be low. Moreover, when the oxide precursor concentration of the oxide precursor-containing liquid is too high, the viscosity of the oxide precursor-containing liquid becomes high and it may be difficult to impregnate.

  As described above, the oxide precursor-containing liquid is preferably a sol or a solution because the oxide precursor can be uniformly coated on the surface of each inorganic fiber of the needle blanket.

  As a dispersion medium or solvent for the oxide precursor-containing liquid, water, an organic solvent such as alcohol, or a mixture thereof, preferably water is used. The oxide precursor-containing liquid may contain a polymer component such as polyvinyl alcohol. Further, a dispersion stabilizer may be added in order to increase the stability of the compound in the sol 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 mix | blended with the oxide precursor containing liquid. Coloring the oxide precursor-containing liquid is preferable in that the areas of the needle blanket impregnated portion and non-impregnated portion can be visually confirmed. The coloring color is preferably black or blue. A water-soluble ink or the like can be used as the colorant.

  A preferable amount of impregnation of the oxide precursor-containing liquid into the needle blanket is as described later.

[Impregnation method of oxide precursor-containing liquid]
In order to impregnate the inorganic fiber needle blanket with the oxide precursor-containing liquid as described above, the needle blanket is immersed in the oxide precursor-containing liquid, and the oxide precursor-containing liquid is interposed between the inorganic fibers of the needle blanket. It only has to penetrate.

  After impregnating the needle precursor with the oxide precursor-containing liquid in this way, the excess liquid is desorbed by suction or compression as necessary so that the desired water content and oxide precursor adhesion amount are obtained. May be. In order to remove excess liquid by suction, it is preferable to attach an attachment that covers the impregnation portion, and to drain the liquid by suction from a suction port provided in the attachment.

  After impregnating the oxide precursor-containing liquid in this way and removing excess liquid as necessary, the oxide precursor-containing liquid may be further dried to a predetermined moisture content as necessary. By doing so, the water content can be reduced while maintaining a high oxide precursor adhesion amount (adhesion amount). By reducing the amount of moisture, the adhesiveness with the adhesive during construction can be increased. Moreover, there exists an advantage by which construction becomes easy by reducing the mass of an inorganic fiber molded object, maintaining flexibility. The drying conditions are appropriately set in the range of 0.5 to 24 hours at 80 to 180 ° C. according to the amount of moisture to be desorbed.

The adhesion amount of the oxide precursor-containing liquid is preferably ₂ to 50 parts by mass with respect to 100 parts by mass of the inorganic fiber as an oxide (CaO and Al ₂ O ₃ ) equivalent as described later.

[Position of impregnation part in needle blanket]
As described above, the heat insulating protective member for skid posts of the present invention is impregnated with an oxide precursor-containing liquid in at least a part of the needle blanket made of inorganic fibers and is in an undried state (hereinafter referred to as `` drying ''). It may be simply referred to as “impregnated part”).

  This impregnation part is preferably formed on the exposed surface (heated surface) of the skid post thermal protection member when the skid post thermal protection member is used in the heating furnace. This is because erosion due to the scale occurs in the non-impregnated portion, and the scale resistance can be improved because all the heated surfaces are impregnated portions.

  The impregnation depth in the blanket thickness direction is preferably 3 mm or more and more preferably 10 mm or more from at least the blanket surface serving as the furnace exposure surface. When the impregnation depth is not less than the above lower limit, the scale resistance is improved. An embodiment in which the needle blanket is impregnated over the entire thickness is preferable because scale resistance is most improved.

  The impregnated part is continuously formed over at least half or more of the plate surface of the plate-shaped needle blanket, and the impregnated part is formed over the entire thickness of the needle blanket in the region where the impregnated part is formed. It is preferable that

  In particular, the impregnation part is preferably formed on both the front and back surfaces of the plate-like needle blanket. More preferably, the impregnation portion on the inner surface of the furnace is formed in a region of 35 to 50% of the thickness with respect to the thickness direction, and the impregnation portion on the surface on the ring-shaped needle blanket 10 side has a thickness with respect to the thickness direction. 20 to 50% of the region. Particularly preferably, the impregnated portion is formed over the entire thickness.

[Moisture content of impregnated part and heat insulating protective member for skid post]
In the heat insulating protective member for skid posts of the present invention, the water content of the impregnated part is 50 to 400 parts by mass with respect to 100 parts by mass of the inorganic fiber of the impregnated part. When the water content in the impregnated portion is excessively small, flexibility is lost due to the binder effect. In addition, the generation of fiber dust increases. On the contrary, when the water content in the impregnated portion is excessively large, the liquid leaks from the inorganic fiber only by applying a little pressure to the inorganic fiber molded body. Moreover, there exists a subject that an inorganic fiber molded object is crushed by dead weight, and, for this reason, peeling of an end surface becomes large. Also, if the water content in the impregnated part is too large, the mass transfer of the sol accompanying the drying of water, which is called migration due to heating during use, becomes intense, the amount of adhesion in the vicinity of the dry surface becomes extremely high, and the amount of internal adhesion Therefore, the thermal shock resistance and the heat shrinkage rate are deteriorated. That is, in order to maintain the uniformity of the entire impregnated part, it is important that the water content of the impregnated part does not exceed 400 parts by mass. Preferably, the moisture content of the impregnation part is 80 to 350 parts by mass with respect to 100 parts by mass of the inorganic fibers of the impregnation part.

  The water content contained in the entire heat insulating protective member for skid posts of the present invention is 50 to 400 parts by mass with respect to 100 parts by mass of inorganic fibers in the entire heat insulating protective member for skid posts. If the moisture content in the heat insulating protective member for skid posts is less than 50 parts by mass with respect to 100 parts by mass of the inorganic fibers, it is difficult to maintain the undried state of the heat insulating protective member for skid posts, and the flexibility becomes low during construction. The problem of peeling or cracking occurs. When the moisture content of the heat insulating protective member for skid post is more than 400 parts by mass with respect to 100 parts by mass of the inorganic fiber, the liquid leaks from the inorganic fiber only by applying a little pressure to the heat insulating protective member for skid post. Moreover, the heat insulating protective member for skid posts is crushed by its own weight, which causes a problem that end face peeling becomes large. The water content of the heat insulating protective member for the skid post is preferably 150 to 300 parts by mass with respect to 100 parts by mass of the inorganic fibers of the entire heat insulating protective member for the skid post.

[Amount of oxide deposited after firing]
In the impregnated part, the oxide precursor-containing liquid has an amount of deposited oxide (CaO and Al ₂ O ₃ ) after firing (hereinafter, sometimes simply referred to as “amount of deposited oxide”) of the impregnated part. The needle blanket is impregnated so as to be 2 to 50 parts by mass with respect to 100 parts by mass. This oxide adhesion amount is preferably 5 to 30 parts by mass, and most preferably 10 to 25 parts by mass with respect to 100 parts by mass of the inorganic fibers in the impregnated part. When the oxide adhesion amount is small, the desired scale resistance may not be obtained. On the other hand, when the amount is too large, the density of the impregnated portion increases, and deterioration of the thermal shrinkage rate, thermal shock resistance and mechanical shock resistance are observed. Further, when the calcium component is present in a large amount on the fiber surface, the calcium component and the inorganic fiber produce a large amount of a low melting point component, so that the heat resistance of the impregnated portion is lowered.

  For the same reason as the oxide adhesion amount of the impregnated part, the oxide adhesion amount of the entire heat insulating protection member for skid posts is 5 to 40 parts by mass with respect to 100 parts by mass of the inorganic fibers of the entire heat insulating protection member for skid posts, In particular, the amount is preferably 8 to 30 parts by mass.

  The molar ratio (Al / Ca) of Al and Ca in the entire impregnated portion of the heat insulating protective member for skid posts of the present invention is 10 to 330, preferably 30 to 100, particularly preferably 32 to 70.

  The whole impregnation part represents the whole of inorganic fibers and deposits constituting the impregnation part. The molar ratio of Al to Ca (Al / Ca) in the entire impregnated part is based on the molar amount of Al contained in the inorganic fibers constituting the needle blanket present in the impregnated part of the inorganic fiber molded body and the oxide precursor containing liquid. It is a ratio of the sum of the molar amount of Ca contained in the inorganic fiber to the sum of the molar amount of Al derived from the sum of the molar amount of Ca derived from the oxide precursor-containing liquid. The molar ratio (Al / Ca) of Al and Ca is substantially equal between the heat insulating protective member for skid post before construction and the heat insulating protective member for skid post fired by heating after construction.

  The Al: Si: Ca molar ratio of the entire impregnated portion of the heat insulating protective member for skid posts of the present invention is 77.2 to 79.5: 18.9 to 21.6: 0.9 to 2.2. From the viewpoint of scale resistance, heat resistance and thermal shock resistance, it is preferable. Here, the molar amount of Al and the molar amount of Ca in the entire impregnated portion are, as described above, each of the molar amounts of Al and Ca contained in the inorganic fibers constituting the needle blanket present in the impregnated portion and the oxide precursor content. It is the sum of the molar amounts of Al and Ca derived from the liquid. The molar amount of Si is the molar amount of Si contained in the inorganic fibers constituting the needle blanket.

  The amount of Al, the amount of Ca and the amount of Si in the impregnated part can be measured by fluorescent X-ray analysis.

[Action of CaO]
When the heat insulating protective member for skid posts of the present invention having an impregnation part is heated in a furnace and the oxide precursor-containing liquid is baked at a high temperature, a part of the CaO component generated from the oxide precursor-containing liquid is inorganic. It diffuses inside the fiber. When the molar ratio of Al to Ca (Al / Ca) in the entire impregnated portion is in the above range, an appropriate amount of CaO diffuses inside the inorganic fiber when fired to a high temperature. The presence of an appropriate amount of CaO inside the inorganic fiber makes it difficult for FeO to diffuse into the inorganic fiber. That is, the reaction between inorganic fibers and FeO is suppressed. This improves the resistance to scaling of the heat-insulating protection member skids post. When the molar ratio of Al to Ca (Al / Ca) in the impregnated part is less than 10, since a large amount of low melting point compound with the inorganic fiber is generated by the inorganic fiber and CaO diffused therein, the heat resistance and heat resistance There is a possibility that the impact property is lowered. Further, when the molar ratio of Al to Ca (Al / Ca) in the impregnated portion is more than 330, the diffusion of CaO is insufficient and the scale resistance may not be improved. Particularly in the case of using mullite _{(3Al 2 O 3 · 2SiO 2} ) composition of the inorganic fibers, when fired at a high temperature, and the crystal phase of mullite, the crystal phase of CaO diffused into mullite component generates. In this case, it is considered that FeO resistance is improved because CaO diffuses inside the fiber while leaving a mullite crystal phase excellent in thermal shock resistance, heat resistance, and mechanical shock resistance.

This is because, after firing the inorganic fiber molded body at 1400 ° C. for 8 hours, as a peak detected by X-ray diffraction (XRD), a peak indicating a mullite crystal phase and a CaO—Al ₂ O ₃ —SiO _{2 This} can be confirmed by the presence of a peak indicating a _two- system crystal phase.

  Moreover, it can be confirmed by element mapping using an electron beam microanalyzer (EPMA) that the Ca component diffuses into the fiber.

[Material of Blanket 40 with Oxide Precursor-Containing Liquid Adhered in Undried State]
As the blanket 40 to which the oxide precursor-containing liquid is attached in an undried state, the above-mentioned oxide precursor-containing liquid is added to 100 mass of the inorganic fiber with respect to the needle blanket of the inorganic fiber having a thickness of about 10 to 30 mm. What was impregnated in the ratio of 2-50 mass parts with respect to a part is preferable.

  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]
A polycrystalline alumina / silica fiber containing 72% by mass of alumina and 28% by mass of silica, which has an average fiber diameter of 5.5 μm and does not substantially contain fibers having a fiber diameter of 3 μm or less, is accumulated and needsling. Needle blanket (trade name MAFTEC ^™ MLS, manufactured by Mitsubishi Chemical Corporation, thickness 25 mm, needle mark density 5 strokes / cm ² , bulk density 128 kg / m ³ (0.128 g / cm ³ ), surface density 3200 g / m ² ) Was punched into a donut shape having an outer diameter (diameter) of 390 mm and an inner diameter (diameter) of 270 mm to produce a ring-shaped needle blanket 10.

In the ring-shaped needle blanket 10, when the residual surface pressure ratio after the cycle test under the conditions described below was measured, the residual surface pressure ratio was 33%.
Conditions: After the ring-shaped needle blanket 10 after firing at 1400 ° C. for 12 hours is compressed to GBD (bulk density) = 0.195 (g / cm ³ ) using a tensile compression tester (Minebea Corp.), the upper and lower plates Was compressed 100 times from GBD = 0.20 (g / cm ³ ) to 0.24 (g / cm ³ ). At that time, the open side pressure value at the first GBD = 0.20 (g / cm ³ ) and the open side pressure value at the 100th GBD = 0.24 (g / cm ³ ) were measured, From the following formula, the residual surface pressure ratio (%), which is an index of the degree of deterioration of the surface pressure after firing, was obtained.
Residual surface pressure ratio = 100th opening side pressure / 1st opening side pressure)

Further, in the ring-shaped needle blanket 10, the measurement of the heat shrinkage rate in the width direction, the longitudinal direction and the thickness direction after firing at 1400 ° C. for 12 hours was carried out by a method based on JIS R3311 (details shown below). The direction was 0.4%, the longitudinal direction was 0.4%, and the thickness direction was 0.0%.
Conditions: A ring-shaped needle blanket 10 was cut to a length of about 150 mm and a length of about 100 mm to obtain a test piece. The test piece was marked by embedding a white silver wire in a rectangular shape of about 120 mm × about 60 mm. It was held for 12 hours in the air heated to a temperature of 1400 ° C. and baked. The heating line shrinkage was calculated by the following formula.

Here, l _{0 is} the length (mm) before firing between the test piece marks, and l _{1 is} the length (mm) after firing between the test piece marks. The heating linear shrinkage ratio is obtained by measuring the length of three points of one test piece and taking the average value of the three points.

  Using this ring-shaped needle blanket 10, it was applied to the skid pipe 1 having a diameter of 270 mm by the procedure of FIGS. The height H from the hearth G to the lower end of the fireproof coating 3 is 1800 mm.

  The number of ring-shaped needle blankets of each compression layer L-1 to L-3, the height dimension after compression, and the compression rate are as follows.

L-1: 27 sheets, height after compression 600 mm, compression rate 10%
L-2: 28 sheets, height after compression 600 mm, compression rate 12%
L-3: 26 sheets, height after compression (T = 560 mm), compression rate 15%

  The gap height h between the third-stage presser plate 20 and the fireproof coating 3 is 20 mm. After attaching one ring-shaped needle blanket 10 to this, all the presser plates 20 are pulled out, and the state shown in FIG. It was. And the average bulk density of L-1, L-2 and L-3 (including the uppermost ring-shaped needle blanket 10) and the uppermost ring-shaped needle blanket 10 press the lower end of the fireproof coating 3. The pressure (pressure between faces) was measured. The results are shown in Table 1.

[Example 2 (the third compression layer is further strongly compressed)]
The same construction as in Example 1 was performed except that the number of ring-shaped needle blankets of the third compression layer L-3 was 28, the compression height was 560 mm, and the compression rate was 20%. The average bulk density of L-1, L-2 and L-3 (including the uppermost ring-shaped needle blanket 10) and the inter-surface pressure were measured. The results are shown in Table 1.

[Comparative Example 1]
The compression rate of the third compression layer L-3 was the same as that of the first and second compression layers L-1 and L-2. That is, the same construction as in Example 1 was performed except that the number of ring-shaped needle blankets of the third compression layer L-3 was 25, the compression height was 560 mm, and the compression rate was 10%. The average bulk density of L-1, L-2 and L-3 (including the uppermost ring-shaped needle blanket 10) and the inter-surface pressure were measured. The results are shown in Table 1. It was a low value compared with Examples 1 and 2.

[Example 3]
A ring-shaped needle blanket 10 laminated compression body having the same compression ratio as in Example 1 was prepared, and mortar was applied to the surface to a thickness of about 3 mm, and an alumina sol solution containing acetic acid as a dispersant was mixed with calcium acetate monohydrate and Al. A blanket that is added so that the molar ratio of Ca (Al / Ca) is 12 and the oxide precursor-containing liquid in which the solid content concentration in terms of oxide is adjusted to 7.0% by mass is impregnated in the entire thickness direction. (Moisture amount 200 parts by weight with respect to 100 parts by weight of inorganic fibers, 18 parts by weight of oxide precursor with respect to 100 parts by weight of inorganic fibers (as oxide), Al / Ca molar ratio (Al / Ca) 64 in the impregnated part, And a bulk density of 0.41 g / cm ³ ). This was fired at a heating rate of 5 ° C./min, 1400 ° C. and held for 12 hours, the blanket 40 on the surface was opened with a cutter knife, the blanket 40 was peeled off, and the surface of the ring-shaped needle blanket 10 laminated compact was externally seen. When observed, the inorganic fiber derived from the blanket 40 was adhered to the entire surface of the ring-shaped needle blanket 10 laminated compressed body.

[Comparative Example 2]
A mortar was applied on the surface of an irregular refractory having a diameter of 340 mm to a thickness of about 3 mm, and the blanket 40 described in Example 3 was wound. This was fired at a heating rate of 5 ° C./min, 1400 ° C. for 12 hours, the surface inorganic fiber molded body was opened with a cutter knife, the blanket 40 was peeled off, and the appearance of the surface of the irregular refractory was observed. However, the inorganic fiber derived from the blanket 40 was adhered to only a part of the surface of the ring-shaped needle blanket 10 laminated compressed body.

[Discussion]
The ring-shaped needle blanket used in the examples has a residual surface pressure ratio of 10% or more after a cycle test after firing (1400 ° C., 12 hours), so that it can sustain long-term vibration in a harsh environment. It can be seen that the surface pressure is high. Moreover, the ring-shaped needle blanket used in the examples uses a ring-shaped needle blanket whose heating line shrinkage after firing (1400 ° C., 12 hours) is 1% or less in all of the width direction, the longitudinal direction, and the thickness direction. Thus, it can be seen that the high temperature dimensional stability is also excellent. Therefore, when the ring-shaped needle blanket used in the examples is compressed and applied, when the bulk density of the compressed layer is evaluated by dividing it into three parts in the upper part, middle part and lower part, the bulk in the upper part is evaluated. It is inferred that by making the density higher than the bulk density in the middle part and the lower part, it is possible to maintain a continuous surface pressure that can withstand long-term vibration in a harsh environment and to suppress the influence of shrinkage due to firing. On the other hand, it is surmised that the comparative example 1 has a low compression rate and thus is low from the initial surface pressure, leaving a gap.

  Moreover, when Example 3 and Comparative Example 2 are compared, the adhesiveness between the blanket 40 and the laminated body 10 of the ring-shaped needle blanket is higher when the inorganic fiber molded body is wound around the laminated compressed body of the ring-shaped needle blanket 10. I understand that. This is because the blanket 40 and the ring needle blanket laminate 10 are made of the same material, so there is no difference in shrinkage due to the material, and the oxide precursor-containing liquid of the blanket 40 is a ring needle blanket laminate. 10 is easy to soak in the surface of the oxide, when the oxide precursor is converted to oxide during firing, the oxide precursor on the interface of the laminate 10 of the blanket 40 and the ring needle blanket becomes an oxide, This is considered because the oxide functions as an adhesive between the blanket 40 and the laminated needle blanket 10. On the other hand, in Comparative Example 2, a space is formed between the blanket 40 and the amorphous refractory due to the difference in shrinkage due to the material between the blanket 40 and the amorphous refractory. As a result, the adhesion is easily reduced. In the heat insulation protective member according to the present invention, it is possible to suppress a reduction in adhesion to the blanket 40 impregnated with the oxide precursor-containing liquid.

Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.
This application is based on Japanese Patent Application No. 2016-093973 filed on May 9, 2016, and is incorporated by reference in its entirety.

DESCRIPTION OF SYMBOLS 1 Skid pipe 2 Skid beam 3 Fireproof coating 4 Anchor metal fitting insertion part 10 Ring-shaped needle blanket 20 Presser plate 21 and 22 Presser plate half 30 Anchor metal fitting 33 Pin

Claims (12)

In the method of constructing a heat insulating protective member below the fireproof coating of the skid pipe having a fireproof coating on the upper part,
A plurality of inorganic fiber ring-shaped needle blankets are externally fitted to the skid pipe to form a stack,
Next, the stack is pushed from above with a presser plate, and the process of forming a compression layer is repeated a plurality of times to form first to nth (n is an integer of 2 or more) compression layers,
The ring-shaped needle blanket is externally fitted between the uppermost compression layer and the lower end surface of the fireproof coating, and then the presser plate is removed to restore the stack, and the ring-shaped needle blanket is moved to the fireproof It is a construction method of a heat insulating protective member pressed against the lower end surface of the coating,
A skid characterized in that when the bulk density of the compressed layer is evaluated by dividing the bulk density into three parts in the upper part, middle part and lower part, the bulk density in the upper part is higher than the bulk density in the middle part and the lower part. Construction method for heat insulation and protection members for pipes.   2. The method for constructing a heat insulating protective member for a skid pipe according to claim 1, wherein the bulk density of the upper compressed layer is 1.1 to 3.0 times the bulk density of the middle and lower compressed layers.   3. The method for constructing a heat insulating protection member for a skid pipe according to claim 1, wherein the bulk density in the middle part is higher than the bulk density in the lower part. The construction of a heat insulating protective member for a skid pipe according to any one of claims 1 to 3, wherein a bulk density of the upper compressed layer is 0.10 g / cm ³ or more and 0.20 g / cm ³ or less. Method. The thermal insulation of a skid pipe according to any one of claims 1 to 4, wherein the ring-shaped needle blanket made of inorganic fibers has a residual surface pressure ratio of 10% or more after a cycle test under the conditions described below. Construction method of protective members.
Conditions: After the ring-shaped needle blanket fired for 12 hours at 1400 ° C. is compressed to GBD (bulk density) = 0.195 g / cm ³ using a tensile compression tester, the upper and lower plates are moved from GBD = 0.20 g / cm ^3. The compression to 0.24 g / cm ³ was repeated 100 times. At that time, the open side pressure value at the first GBD = 0.20 g / cm ³ and the open side pressure value at the 100th GBD = 0.24 g / cm ³ were measured. A residual surface pressure ratio (%) is obtained as an index of the degree of deterioration of the rear surface pressure.
Residual surface pressure ratio = 100th opening side pressure / first opening side pressure × 100   In any one of Claims 1-5, as for the said ring-shaped needle blanket made from an inorganic fiber, 1400 degrees C and the heat shrinkage rate of the width direction, a longitudinal direction, and the thickness direction after baking for 12 hours are all 1% or less. A method for constructing a heat insulating and protecting member for a skid pipe, characterized in that: In any one of Claims 1-6, the slit of radial direction is provided in the said ring-shaped needle blanket,
A method for constructing a heat insulating protection member for a skid pipe, wherein the ring-shaped needle blanket is fitted onto the skid pipe by opening the slit.   8. The method for constructing a heat insulating and protecting member for a skid pipe according to claim 7, wherein the slits of the ring-shaped needle blanket are shifted in the circumferential direction so as not to overlap each other. In any one of Claims 1-8, the anchor metal fitting insertion part is provided in the skid pipe,
Construction of a heat insulating protective member for a skid pipe characterized in that an anchor metal for preventing upward movement of the presser plate is locked to the anchor metal fitting insertion part to prevent upward movement of the presser plate. Method.   The construction of the heat insulating protective member for a skid pipe according to claim 9, wherein the anchor metal fitting has a pin protruding vertically, and the pin is pierced through a ring-shaped needle blanket overlapping the presser plate. Method.   In any 1 item | term of Claims 1-10, the blanket with which the oxide precursor containing liquid was adhered to the outer periphery of the ring-shaped needle blanket in the undried state is wound, and this oxide precursor containing liquid is then The construction method of the heat insulation protective member of a skid pipe characterized by including the component which produces the alumina calcia composition containing aluminum oxide and calcium oxide by baking. In the skid pipe with a heat insulating protective member in which a heat insulating protective member is provided below the fire protective coating of the skid pipe having a fire protective coating on the upper part,
The heat insulation protective member has a stack of compressed ring needle blankets that are externally fitted to a skid pipe, and the uppermost ring needle blanket is pressed against the fireproof coating by the repulsive force of the stack. A skid pipe with a thermal insulation protection member,
When the stack is evaluated by dividing it into three parts at the upper part, middle part and lower part in the height direction, the bulk density of the ring-shaped needle blanket in the upper part is larger than the bulk density of the ring-shaped needle blanket in the middle part and the lower part. A skid pipe with a heat-insulating protective member, characterized by being high.

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