KR20190004268A - Construction method of skid pipe and its thermal insulation protection member - Google Patents

Abstract

There is provided a skid pipe with an adiabatic protection member in which a gap at the upper end of the adiabatic protecting member is more sufficiently prevented, and a method of constructing the adiabatic protecting member.
A plurality of ring-shaped needle blanket 10 is wound around a skid pipe 1 and pressed by a press plate 20 to form a first compression layer L-1. The second compression layer L-2 and the third compression layer L-3 are formed on the upper side thereof, and are pressed by the pressure plate 20, respectively. After the ring-shaped needle blanket 10 is loaded between the refractory jacket 3 and the press plate 20, the press plate 20 is taken out. The compression ratio of the third compression layer L-3 is made larger than that of the first and second compression layers L-1 and L-2.

Description

Construction method of skid pipe and its thermal insulation protection member

TECHNICAL FIELD The present invention relates to a skid pipe in a heating furnace, and a method of constructing the heat insulating protective member.

As a protecting member of a skid pipe in a heating furnace of a steel industry, an inorganic fiber aggregate having high thermal shock resistance and an inorganic fiber molded article have been used (Patent Documents 1 and 2).

Patent Document 1 discloses coating a skid pipe with a ring-shaped heat insulating material made of a ceramic fiber. In the paragraphs of FIGS. 8 and 0002 of Patent Document 1, it is described that a ring-shaped heat insulator, which is partially cut, is mounted on a skid pipe. Patent Document 1 does not describe the construction after compressing the heat insulator.

Patent Document 2 discloses a heat insulating material construction method in which a plurality of refractory materials made of semi-refractory ceramic fiber are superimposed, compressed, placed on the outer periphery of the heating furnace while maintaining the compression state, and decompressed to restore the refractory material made of ceramic fiber . According to this construction method, a phenomenon that a gap is formed on the upper side of the support pipe due to the refractory shrinkage is suppressed.

Patent Document 1: Japanese Laid-Open Patent Publication No. 2004-43918 Patent Document 2: JP-A-2010-151284

The present invention relates to a skid pipe in which a skid pipe is wrapped around an adiabatic protection member made of an inorganic fiber molded body, wherein a skid pipe with an adiabatic protection member is more effectively prevented from generating a gap at an upper end of the adiabatic protective member, The present invention has been made to solve the above problems.

[1] A method for constructing a heat insulating protective member below a refractory sheath of a skid pipe having a refractory coating on the upper part, comprising the steps of extruding a plurality of inorganic fiber ring type needle blanket into the skid pipe to form an impact sheath, (N is an integer of 2 or more) compressed layers are formed by repeating the step of pressing the sieve from the upper side and forming the compressed layer from the upper side to form the compression layer at the uppermost stage and the lower end Wherein said ring-shaped needle blanket is extruded between said ring-shaped needle blanket and a surface of said ring-shaped needle blanket, then said press plate is demolished to restore a weight, and said ring-shaped needle blanket is pressed against the lower end surface of said refractory cover, In the case where the bulk density of the compression layer is divided into three parts by the upper, middle, and lower portions in the height direction, And the volume density of the lower portion is higher than the bulk density of the lower portion.

[2] The method according to [1], wherein the upper compression layer has a bulk density of 1.1 to 3.0 times the bulk density of the middle and lower compression layers.

[3] The method according to [1] or [2], wherein the bulk density in the central portion is higher than the bulk density in the lower portion.

[4] The method according to any one of [1] to [3], wherein the upper compression layer has a bulk density of 0.10 g / cm3 or more and 0.20 g / cm3 or less.

[5] The blanket according to any one of [1] to [4], wherein the inorganic filler ring type needle blanket has a residual surface pressure ratio of 10% or more after the cycle test under the conditions described below. Method of construction of members.

Condition: The ring-type needle blanket after firing at 1400 占 폚 for 12 hours was compressed to GBD (bulk density) = 0.195 by a tensile compression tester, and the upper and lower plates were compressed 100 times from GBD = 0.20 to 0.24. At that time, the open side surface pressure value at the first GBD = 0.20 and the open side surface pressure value at the 100th GBD = 0.24 were measured, and the residual surface pressure as an index of the degree of deterioration of the surface pressure after firing Find the ratio (%).

Remaining surface pressure ratio = 100th open surface pressure / first open surface pressure 100

[6] The inorganic fiber ring type needle blanket according to any one of [1] to [5], wherein the heat shrinkage ratio in the width direction, the longitudinal direction and the thickness direction after firing at 1400 ° C for 12 hours is 1% Wherein the method comprises the steps of:

[7] The skid pipe according to any one of [1] to [6], wherein the ring-shaped needle blanket is provided with a slit in the radial direction, A method of constructing a heat insulating protective member of a pipe.

[8] The method as set forth in [7], wherein the slit of the ring-shaped needle blanket is shifted in the circumferential direction so as not to overlap each other.

[9] In any one of [1] to [8], an anchor bracket inserting portion may be formed in the skid pipe, and an anchor bracket for stopping the upward movement of the presser plate may be attached to the anchor- And the upward movement of the skid pipe is prevented.

[10] The heat insulating protective member of a skid pipe according to [9], wherein the anchor bracket has pins projecting upward and downward, and the pin is passed through the ring-shaped needle blanket superimposed on the press plate Construction method.

[11] The method according to any one of [1] to [10], wherein a blanket having an oxide precursor-containing liquid adhered in an undried state is wound around the outer periphery of the ring-shaped needle blanket, Containing liquid comprises a component which generates an alumina-calcium oxide-based composition containing aluminum oxide and calcium oxide by firing.

[12] A skid pipe with a heat insulating protective member formed below a refractory sheath of a skid pipe having a refractory sheath on the upper part, wherein the heat insulating protective member comprises a ring-shaped needle blanket extruded into a skid pipe Wherein the uppermost ring-shaped needle blanket is pressed against the refractory sheath by the repulsive force of the weight, the skid pipe having the heat insulating protective member attached thereto is divided into three parts by the upper, middle and lower portions in the height direction Wherein the volume density of the ring-shaped needle blanket at the upper portion is higher than the bulk density of the ring-shaped needle blanket at the center portion and the lower portion.

In the skid post in which the heat insulating protective member is applied by the method of the present invention, the ring-like needle blanket disposed on the uppermost n-th compression layer is formed in the ring-shaped needle blanket of the first to n- Pressed by the repulsive force, and pressed against the lower surface of the refractory coating. Particularly, in the present invention, when the bulk density of the compression layer is evaluated by dividing the volume density of the compression layer by the upper, middle and lower portions in the height direction, the bulk density at the upper portion is higher than the bulk density at the middle portion and lower portion When the ring type needle blanket of the high, especially the first to nth compression layers is applied with the same ring type needle blanket, the ring type needle blanket of the upper compression layer is most strongly compressed so that the ring type needle blanket . This repulsive force is maintained even when the furnace is operated, and prevents a gap between the refractory covering caused by the vibration generated when the slab is conveyed and the uppermost ring-shaped needle blanket for a long period of time. INDUSTRIAL APPLICABILITY By using an inorganic fiber ring type needle blanket according to the present invention, the repulsive force is increased and it is possible to effectively prevent a gap from being generated.

In one aspect of the present invention, by covering the outer side of the laminated compressed layer with a blanket having an oxide precursor-containing liquid adhered in an undried state, a separate baking step is carried out so that the coated blanket has a high durability Containing aluminum oxide and calcium oxide. If the erosion due to the scale is not adversely affected by the laminated compression layer, the blanket can be easily cut and re-coated so that it is excellent in water retention and low cost. By using an alumina fiber needle mat, lightweight, excellent workability, and excellent weatherability and thermal shock are obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a method of applying an adiabatic protection member according to an embodiment; FIG.
2 is a perspective view showing a construction method of the heat insulating protective member according to the embodiment;
3 is a perspective view showing a construction method of the heat insulating protective member according to the embodiment.
FIG. 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.
5 is a perspective view showing a construction method of the heat insulating protective member according to the embodiment;
6 is a perspective view showing a construction method of the heat insulating protective member according to the embodiment.
7 is a perspective view showing a construction method of the heat insulating protective member according to the embodiment.
8A is a perspective view showing a method of applying the heat insulating protective member according to the embodiment, and FIG. 8B is a sectional view taken along line VIIIb-VIIIb in FIG. 8A.
9 is a plan view showing another shape of the presser plate.
10 is a cross-sectional view showing a connecting structure of a presser plate.

Hereinafter, embodiments will be described with reference to Figs.

As shown in Fig. 1, the skid pipe 1 to which the heat insulating protective member is applied is of a heat-resistant steel pipe type, and is installed standing up from a hearth G of the heat treatment furnace. And the skid beam 2 is supported by a plurality of skid pipes 1. A refractory sheath 3 made of a fire-resistant castable is formed on the skid pipe 1. In the present invention, the heat insulating protective member is installed on the lower side of the refractory sheath 3 of the skid pipe 1. [

In this skid pipe 1, a plurality of anchor-metal-inserting portions 4 are formed at intervals in the height direction. As shown in Fig. 4B, a clearance C (Fig. 4B) for inserting the anchor fitting from above is formed between the anchor fitting 4 and the outer peripheral surface of the skid pipe 1 Respectively.

Since the skid pipe 1 may not be circular in horizontal section, it is preferable that the outer periphery of the skid pipe 1 is covered with the foundation layer 5 (see Fig. 8B) prior to the construction of the heat insulating protective member desirable. By covering the base layer 5, the horizontal cross-sectional shape of the outer circumferential surface becomes substantially a circular shape, the adhesion between the outer circumferential surface and the laminated compressed layer becomes higher, and a higher heat insulating effect can be exhibited. The base layer 5 is made of inorganic fiber, castable refractory or the like.

In the present invention, a plurality of annular materials (hereinafter referred to as ring-like needle blanket) 10 made of needle blanket of inorganic fibers (alumina fibers in this embodiment) are mounted on the lower portion of the skid pipe 1. As the annular material, it is preferable to use needle blanket of inorganic fiber having high repulsive force. In the ring-shaped needle blanket 10, a slit 11 (Fig. 2) is formed in the radial direction, and the ring-shaped needle blanket 10 is extruded into the skid pipe 1 with the slit 11 opened. It is preferable that the direction of the ring-shaped needle blanket 10 is changed by one step so that the slits 11 are not overlapped to prevent a gap from being formed in the extrinsic portion.

After the ring-shaped needle blanket 10 of the required number is superimposed, the push plate 20 is disposed above the uppermost ring-like needle blanket 10 as shown in Fig.

 In this embodiment, the presser plate 20 is constituted by abutting two press plate half bodies 21 and 22.

The press plate half bodies 21 and 22 have approximately semicircular curved side edges 21a and 22a on the opposite sides, respectively. Both sides of the curved side edges 21a and 22a are arm-like portions 21b and 22b. Each of the upper portions 21b, 22b is provided with a small hole 24 for inserting a bolt. The front ends of the top ends 21b and 22b are overlapped with each other so that the curved side edges 21a and 22a face each other and are fastened together with the bolts 23 (Figs. 3 and 4A). A circular opening 25 (Figs. 3, 4A, and 4B) is formed in this presser plate 20.

Each of the curved portions 21a and 22a has a U-shaped cutout portion 26 formed therein. The notches 26 are arranged to face each other in the radial direction of the opening 25. The notch 26 is for passing the pin 33 of the anchor fitting 30.

L-shaped cutouts 27 are formed on the back side of the pressure plate half bodies 21, 22 (sides opposite to the curved side edges 21a, 22a). A belt is attached to the notch 27 as described later. In the vicinity of the rear side of the press plate half bodies 21 and 22, a small hole 28 for passing a string body or for attaching a hand or a tool when the press plate half bodies 21 and 22 are pulled out is formed.

The pressure plate 20 is formed by extruding the push plate half bodies 21 and 22 in the skid pipe 1 by approaching the push plate half bodies 21 and 22 from both sides with the skid pipe 1 therebetween and by the bolts 23 , And presses the weight of the ring-like needle blanket 10 from above by using the pressure plate 20 and compresses it.

The compression method is not particularly limited, but a compression method using a belt and the like can be mentioned. Among them, a compression method using a belt is most preferable because it is the least costly and easy. It is preferable that the pressing plate 20 has an L-shaped notch 27 so that the pressing belt 20 is easily engaged and the belt is easily taken out after compression. In the case of the above.

The anchor metal fitting 30 is inserted into the anchor metal fitting portion 4 and fixed by the wedge 35 in a state in which the pressing body of the ring-like needle blanket 10 is pressed by the pressing plate 20.

As shown in Figs. 3, 4A and 4B, the anchor metal fitting 30 is a heat-resistant mandrel having an inverted L shape as viewed from the side having the longitudinal piece 31 and the transverse piece 32. [ The piece piece 31 is inserted into the clearance C between the anchor metal insertion portion 4 and the outer peripheral surface of the skid pipe 1. [ The transverse piece (32) is provided with a pin (33) projecting upward and downward. The pin 33 is inserted into the ring-shaped needle blanket 10 which is pressed by the press plate 20 by passing through the cutout portion 26. Then, the portion of the pressure plate 20 pressing the ring-shaped needle blanket 10 in the vicinity of the notch 26 is pressed from the upper side by the transverse piece 32.

Thereafter, a wedge 35 is inserted between the piece of primary material 31 and the skid pipe 1, and the push plate 20 is fixed to the skid pipe 1. Thereby, the first-stage pressure plate 20 is fixed to the skid pipe 1, and a first compression layer L-1 in which a plurality of ring-shaped needle blanket 10 are compressed is formed below the pressure plate 20.

Thereafter, as shown in Fig. 5, a ring-shaped needle blanket 10 of a required length is superimposed on the skirt pipe 1 on the upper side of the first-stage pressure plate 20, as shown in Fig. Further, the upward pin 33 of the anchor fitting 30 is inserted and passed through the ring-shaped needle blanket 10. Next, the second stage pressure plate 20 is extruded to the skid pipe 1, the weight of the ring type needle blanket 10 is compressed, and the second stage pressure plate 20 is fixed to the skid pipe 1). Thus, the second compressed layer L-2 is formed.

A ring-shaped needle blanket 10 of the required length is superimposed on the upper surface of the second-stage pressure plate 20 so as to surround the skid pipe 1. Further, the upward pin 33 of the anchor fitting 30 is inserted and passed through the ring-shaped needle blanket 10. The pressure plate 20 of the third stage is extruded to the skid pipe 1 and the weight of the ring type needle blanket 10 is compressed and the pressure plate 20 of the third stage is fixed to the skid pipe 1). Thereby, the third compressed layer L-3 is formed.

5, the skid pipe 1 is surrounded by the three-stage compression layers L-1, L-2, and L-3. When forming the uppermost third compressed layer (L-3), the pressing pressure to press the ring-shaped needle blanket weight with the third-stage pressure plate (20) is set to be the pressure at the time of forming the first and second compression layers Make it bigger than pressure. Thus, the uppermost third compressed layer L-3 is compressed more strongly than the first and second compressed layers L-1 and L-2.

As shown in Fig. 5, since there is a gap between the uppermost third compressed layer L-3 and the refractory cast 3 made of a fire-resistant castable, the ring-shaped needle blanket 10 ) Are piled up and arranged. In this case also, the pin 33 is pierced and passed through the ring-shaped needle blanket 10 on the upper side of the uppermost pressure plate 20.

6, the bolts 23 of each presser plate 20 are taken out, and the presser plate half bodies 21, 22 are pulled out by pulling them in the direction of arrow F in Fig. The ring-like needle blanket 10 superimposed on the presser plate 20 is not pulled out by the presser plate 20 because the pin 33 is pierced and fixed. When pulling out the press plate half bodies 21 and 22, it is preferable to put a string-like body, a finger, a tool, or the like on the small holes 28 of the press plate half bodies 21 and 22.

The ring-shaped needle blanket 10 disposed on the upper side of the uppermost third compression layer L-3 is pressed against the pressure plate 20 of the first to third compression layers L-1 to L- Is pressed by the repulsive force of the ring-shaped needle blanket 10 and is pressed against the lower end surface of the refractory covering 3. Particularly, in this embodiment, the same ring-type needle blanket 10 is used in the first to third compression layers L-1 to L-3, and the uppermost third compression layer L- The volume density of the uppermost third compression layer L-3 is higher than that of the first compression layer L-1 and the second compression layer L-2, because the ring-like needle blanket 10 of the ring- The ring-like needle blanket 10 immediately under the refractory sheath 3 is strongly pressed against the refractory sheath 3, since it is higher than the bulk density of the refractory sheath 3. This repulsive force is also maintained during the operation of the furnace and prevents the gap between the refractory sheath 3 and the uppermost ring-shaped needle blanket 10 caused by the vibration generated during slab conveyance for a long period of time.

In the above embodiment, the press plate 20 is composed of two press plate half bodies 21 and 22, but the press plate 20 may be three press plates, four press plates, or five or more platelets. When the press plate is constituted by three or more platelets, the ring-shaped needle blanket 10 is not easily wrinkled at the time of taking out the platelet, and the resistance force at the time of withdrawal becomes smaller than in the case of two plates.

Fig. 9 is a plan view of the press plate 20 'constituted by three press plate three-piece bodies 21'.

Each presser plate three-piece body 21 'is of a fan shape, and the notched portion 26 is formed on the inner circumferential edge thereof, and the L-shaped notch portion 27 is formed on the outer circumferential edge thereof. Further, the small hole 28 is formed in the vicinity of the outer peripheral edge.

The annular presser plate 20 'is constituted by overlapping both sides (diametrical sides) of each presser plate three-piece body 21' with each other and connecting them with the bolts 23. The ring-shaped needle blanket 10 can be constructed in the same manner as in the above embodiment by using the presser plate 20 '.

In the above embodiment, the step portions are formed on one upper surface and the other lower surface in the overlapping portions of the pressure plate half bodies 21, 22 or between the pressure plate third bodies 21 ', but as shown in Fig. 10, The projecting piece 210 is fixed to the upper surface of the pressing plate half 21 of the other pressing plate half 21 by welding or the like so that the projecting piece 210 is projected to the upper surface of the other pressing plate half 22, The pressure plate half bodies 21 and 22 may be connected to each other by passing the pressure plate half bodies 21 and 22 through the nut body 210 and the pressure plate half body 22. The press plate three bodies 21 'may be connected in the same manner. In Fig. 10, the protruding piece 210 is formed on the upper surface side of the press plate half bodies 21 and 22, but it may be formed on the lower surface side.

After the presser plate 20 (or 20 ') is drawn out as described above, the blanket 40 (40') having an oxide precursor-containing liquid adhered to the outer periphery of each ring-shaped needle blanket 10 ) Is closed, and the construction is completed. The blanket 40 to which an oxide precursor-containing liquid is adhered in an undried state is subjected to a separate calcination step to obtain a blanket containing alumina and calcia-based compositions containing aluminum oxide and calcium oxide.

By winding the blanket 40, the blanket containing the alumina / calcia-based composition after firing can receive the wind vertically proceeding parallel to the laminated compression layer originally. Therefore, the protective member of the skid pipe The hot air intrusion can be effectively prevented.

The blanket (40) needs to be fixed with an adhesive or a tape as necessary. The adhesive is preferably a heat-resistant curing agent. Since the blanket 40 is different in material from the monolithic refractory, there is a contraction difference caused by the material, and as a result, the blanket 40 does not adhere well to the monolithic refractory, and the blanket 40 and the monolithic refractory There is a possibility that a space is generated between the two. However, since the laminate 10 of the blanket 40 and the ring-shaped needle blanket 10 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 on the ring- The oxide precursor on the interface of the blanket 40 and the ring-shaped needle blanket layer 10 becomes an oxide when the oxide precursor is converted into oxide upon firing, Since the oxide functions as an adhesive between the blanket 40 and the layered body 10 of the ring-shaped needle blanket, the adhesion of the blanket 40 to the layered body 10 of the ring-shaped needle blanket is remarkably improved. The blanket (40) may be wound on only one layer or two or more layers. Further, it is preferable that the blanket 40 containing the refractory covering and the ring-shaped needle blanket is wound above the joint so that the blanket containing the alumina / calcia-based composition after firing can suppress the intrusion of heat into the gap portion .

Further, even if the outermost surface of the blanket containing the alumina / calcia-based composition after firing is subjected to scale erosion due to the blanket 40 being wound in two or more layers, the inside of the blanket containing alumina / calcia- The scale can be blocked over a long period of time because the blanket surface containing the alumina-calcia-based composition without erosion appears. When the alumina-calcia-based composition-containing blanket surface not subjected to scale erosion is absent on the inner side, the alumina-calcia-containing composition remaining blanket on the surface can be easily removed using a cutter or a slider. Since at least one year can withstand scale erosion, the frequency of maintenance can be greatly reduced. Since the blanket (40) is wound again, it is possible to obtain the inner scale property again, so that the cost is low and the water retention property is excellent. Since the laminated body 10 of the ring-shaped needle blanket inside the blanket 40 is not subjected to erosion by the scale, it can be used for a long period of time by periodically exchanging the blanket 40.

Although the first to third compressed layers L-1 to L-3 are formed by dividing and compressing the ring-type needle blanket 10 three times in the above embodiment, the height of the skid pipe 1 Accordingly, it may be performed twice or four or more times.

When the bulk density of the compressed layer is evaluated by dividing into three equal parts in the height direction, upper, middle and lower, the bulk density at the upper part is higher than the bulk density at the middle part and lower part, The bulk density of the upper compression layer is 1.1 to 3.0 times, preferably 1.2 to 2.0 times, more preferably 1.3 to 1.7 times the bulk density of the middle and lower compression layers. By setting the bulk density of the upper compression layer to the above range with respect to the bulk density of the middle and lower compression layers, the ring-like needle blanket constituting the compression layer is not collapsed and is generated at the time of slab transportation at the time of operation of the furnace And the generation of gaps between the uppermost ring-shaped needle blanket and the refractory coating caused by the vibration is suppressed.

Further, the bulk density at the center portion is higher than the bulk density at the lower portion. The ring-type needle blanket constituting the compression layer is not pressurized, and the vibration generated when the slab is conveyed during the operation of the furnace And the generation of gaps between the uppermost ring-shaped needle blanket and the refractory coating generated by the ring-shaped needle blanket is suppressed.

The volume density of the upper compressed layer is usually 0.10 g / cm3 or more and 0.20 g / cm3 or less, preferably 0.12 g / cm3 or more and 0.18 g / cm3 or less, more preferably 0.14 g / cm3 or more and 0.16 g / 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 from 0.10 g / cm3 to 0.20 g / cm3, preferably from 0.13 g / cm3 to 0.16 g / cm3 to be.

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. And is usually not less than 0.10 g / cm3 and not more than 0.20 g / cm3, preferably not less than 0.13 g / cm3 and not more than 0.16 g / cm3.

Of the ring-shaped needle blanket 10 of the upper compression layer (ring-shaped needle blanket 10 disposed above the third compression layer L-3 and the third compression layer L-3 in the above embodiment) ([(Original thickness) - (thickness after compression)] x 100 / [original thickness]) is not particularly limited as far as the relationship of the above-mentioned bulk density is satisfied, but is usually 10% % Or more, and usually 30% or less, especially 25% or less, especially 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, especially 7% or more and especially 8% , Preferably 20% or less, particularly 18% or less, particularly 15% or less. The compression ratio at the upper portion is preferably at least 1.1 times, particularly at least 1.5 times, more preferably at most 4 times, especially at most 3 times, the compression ratio of the middle and lower compression layers. It is more preferable that the compression ratio of the middle portion is higher than that of the lower portion.

The bulk density of one ring-type needle blanket 10 before compression is not particularly limited, but is usually 0.05 g / cm3 or more, preferably 0.06 g / cm3 or more, particularly preferably 0.08 g / cm3 or more, usually 0.18 g / Cm3, preferably not more than 0.16 g / cm3, particularly preferably not more than 0.14 g / cm3.

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

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

The height from the hearth G to the lower end of the refractory sheath 3 is H and the height of the gap formed between the uppermost pressure plate 20 and the refractory sheath 3 in the state of Fig. , H / H is preferably 0.005 or more, particularly 0.01 or more, and more preferably 0.05 or less, especially 0.035 or less.

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

The diameter of the ring-shaped needle blanket 10 (that is, a value of 1/2 of the difference between the outer diameter (diameter) and the inner diameter (diameter)) is at least 3% It is preferably 85% or less, particularly 80% or less.

There is no particular limitation on the ring-type needle blanket 10, but the residual surface pressure ratio after the cycle test under the conditions described below is 10% or more, preferably 12% or more, and more preferably 15% or more .

After compressing the ring-type needle blanket 10 calcined at 1400 占 폚 for 12 hours to a GBD (bulk density) of 0.195 g / cm3 by a tensile compression tester, the upper and lower plates were changed from GBD = 0.20 g / cm3 to 0.24 g / Compression was repeated 100 times. At that time, the open side surface pressure value at GBD = 0.20 g / cm < 3 > at the first time and the open side surface pressure value at GBD = 0.24 g / (%) Which is an index of the remaining surface pressure ratio.

Remaining surface pressure ratio = 100th open surface pressure / first open surface pressure

Since the residual surface pressure ratio is in the above range, the repulsive force of the ring-like needle blanket can be maintained even during the operation of the furnace, the clearance between the ring-like needle blanket can be prevented for a long period of time, It is preferable in that the gap between the generated refractory coating and the uppermost ring-shaped needle blanket can be prevented over a long period of time.

In the ring-type needle blanket 10, the heating linear shrinkage ratio in the width direction, the longitudinal direction and the thickness direction after firing (1400 DEG C, 12 hours) is not particularly limited, but a method according to JIS R3311 ) Is preferably 1% or less, more preferably 0.5% or less. Since the heating linear shrinkage is in the above range in both the width direction, the longitudinal direction, and the thickness direction, the ring type needle blanket is preferable because it has excellent stability at high temperature and is difficult to decrease in thickness.

Condition: The specimen is cut into a length of about 150 mm and a length of about 100 mm to prepare a test piece. A white silver line is embedded in the test piece in a rectangular shape of about 120 mm × about 60 mm for display. It is held in an atmosphere heated to a temperature of 1400 캜 for 12 hours. The heating wire shrinkage ratio is calculated by the following formula.

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

[Materials such as ring-type needle blanket 10]

Next, a suitable material of the ring-type needle blanket 10 and the blanket 40 to which the oxide precursor-containing liquid is adhered will be described.

The ring-like needle blanket 10 is not particularly limited as long as it is an inorganic fiber-based blanket, but is preferably a needle blanket of an inorganic fiber to be described later.

The blanket (40) having an oxide precursor-containing liquid adhered in an undried state contains a component for generating an alumina · calcia-based composition containing aluminum oxide and calcium oxide by firing in the inorganic fiber-based blanket . Preferably, the impregnated portion is formed of a needle blanket of inorganic fibers, and at least a part of the needle blanket is in an undried state with an oxide precursor-containing liquid adhered thereto, and the moisture content of the impregnated portion is 100 mass% And the water content of the entire heat insulating protective member is 50 to 400 parts by mass with respect to 100 parts by mass of the inorganic fibers in the entire heat insulating protective member, and the oxide precursor containing liquid is aluminum oxide (Al ₂ O ₃ and CaO may be either a single or a double oxide) containing calcium oxide (Al ₂ O ₃ ) and calcium oxide (CaO), and in the impregnation section , The oxide precursor-containing liquid is adhered in an amount of 2 to 50 parts by mass relative to 100 parts by mass of the inorganic fibers of the impregnation portion as an oxide conversion amount, Full a molar ratio (Al / Ca) of Ca and Al in the (inorganic fibers and the whole of the deposit) of 10 or more 330 or less.

In particular, the inorganic fiber blanket of the blanket 40 is preferably identical to the inorganic fiber blanket of the ring needle blanket 10.

The bulk density of the blanket 40 is usually 0.10 to 0.75 g / cm3, preferably 0.15 to 0.60 g / cm3, and particularly preferably 0.20 to 0.45 g / cm3.

[Needle Blanket]

The needle blanket of the inorganic fiber (hereinafter simply referred to as " blanket " or " needle blanket ") used in the heat insulating protective member of the present invention will be described.

It is preferable that the needle blanket be subjected to a needling treatment on a fibrous aggregate of inorganic fibers substantially free of fibers having a fiber diameter of 3 占 퐉 or less. By using such a needle blanket, it is possible to enhance the weather resistance of the heat insulating protective member for a skid post of the present invention.

≪ Inorganic fiber &

The inorganic fiber constituting the needle blanket is not particularly limited and examples thereof include silica, alumina / silica, zirconia, spinel, titania and calcia containing them, or a composite fiber. Particularly preferably, (Toughness), and from the viewpoint of safety, alumina / silica-based fibers, especially polycrystalline alumina / silica-based fibers.

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

In the present invention, it is preferable that 80% by mass or more, preferably 90% by mass or more, particularly preferably all of the inorganic fibers are polycrystalline alumina / silica-based fibers having the mullite composition. In addition, the molar ratio (Ca / Al) of Ca to Al in the inorganic fibers is preferably 0.03 or less, and it is particularly preferable that the inorganic fibers do not contain Ca.

The inorganic fibers preferably do not substantially contain fibers having a fiber diameter of 3 mu m or less. Here, substantially no fiber having a fiber diameter of 3 占 퐉 or less is meant to indicate that the fiber having a fiber diameter of 3 占 퐉 or less is 0.1% by mass or less of the total fiber weight.

The average fiber diameter of the inorganic fibers is preferably 5 to 7 mu m. If the average fiber diameter of the inorganic fibers is excessively large, the repulsive force and toughness of the fiber aggregate disappear. If the inorganic fibers are excessively thin, the oscillation amount floating in the air increases and the probability of containing fibers with a fiber diameter of 3 탆 or less increases .

<Needle Blanket Manufacturing Method>

The inorganic fiber aggregate having the above-mentioned appropriate average fiber diameter and substantially not containing fibers having a fiber diameter of 3 탆 or less can be obtained by controlling the spinning liquid viscosity in the production of the inorganic fiber aggregate by the sol- Control of air flow used in the elongation chamber, control of drying of the stretching chamber, control of needling, and the like.

The needle blanket can be obtained by a conventional method, for example, as disclosed in Japanese Patent Application Laid-Open No. 2014-5173, a step of obtaining an aggregate of inorganic fiber precursors by a sol-gel method, And a firing step of firing an aggregate of needled inorganic fiber precursors into an inorganic fiber aggregate.

&Lt; Needle dent density, bulk density and thickness of needle blanket >

It is preferable that the needle blanket density of the needle blanket is 2 to 200 ratios / cm 2, particularly 2 to 150 ratios / cm 2, particularly 2 to 100 ratios / cm 2, particularly 2 to 50 ratios / cm 2. If the needle thread density is too low, uniformity of the thickness of the needle blanket is lowered, and thermal shock resistance is lowered. If the needle thread density is too high, there is a fear that the fibers are damaged and scattered after firing.

The needle blanket preferably has a bulk density of 50 to 200 kg / m 3 (0.05 to 0.2 g / cm 3) and more preferably 80 to 150 kg / m 3 (0.08 to 0.15 g / cm 3). An excessively low bulk density results in a weak inorganic fiber formed body. If the bulk density is too high, the mass of the inorganic fiber formed body is increased and the repulsive force is lost, resulting in a molded body with 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, only a very thin molded article is obtained, the availability as a heat-insulating inorganic fiber molded article is low, and if the surface density is excessively large, the amount of fibers is excessively large. It becomes difficult to control the thickness.

The thickness of the needle blanket is preferably about 2 to 35 mm. However, as described later, the thickness of the needle blanket is preferably 3 mm or more, more preferably 3 mm or more, Mm or more, particularly preferably 10 mm or more.

Further, in the present invention, the needle blanket of inorganic fibers is formed into a plate shape. However, the plate type needle blanket may be rolled at the time of handling.

[Oxide precursor-containing liquid]

The oxide precursor-containing liquid impregnated in the needle blanket includes an oxide precursor, which is a component which generates an alumina · calcia-based composition containing aluminum oxide (Al ₂ O ₃ ) and calcium oxide (CaO) by firing . In this alumina · calcia-based composition, Al ₂ O ₃ and CaO may be a single compound or a double oxide of Al ₂ O ₃ and CaO. Examples of the double oxide of Al ₂ O ₃ and CaO include CaO · Al ₂ O ₃ , CaO · 2Al ₂ O ₃ , CaO · 6Al ₂ O ₃ and the like, but the present invention is not limited thereto.

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

(I) Al ₂ O ₃ group and CaO group

(Ii) a mixture of Al ₂ O ₃ and CaO and a double oxide

(Iii) an Al ₂ O ₃ group and a double oxide

(Iv) CaO and double oxides

(V) only double oxides

The oxide precursor-containing liquid contains at least a component containing Ca and a component containing Al. Specific examples of the component containing Ca include hydroxides, chlorides, acetates, lactates, nitrates, carbonates and the like of calcium. These may be contained in the oxide precursor-containing liquid alone or in two or more species. Of these, calcium acetate, hydroxide, or carbonate is preferred because the components generated during firing are mainly water and carbon dioxide, and do not deteriorate the metal members, steel plates, and the like in the furnace.

The Ca-containing component may be dissolved in the oxide precursor-containing liquid, may be in the form of a naphtha, or may be in a dispersed phase. Since the component containing Ca is dissolved in the oxide precursor-containing liquid or uniformly dispersed, the oxide precursor can be uniformly coated on the entire surface of each inorganic fiber constituting the needle blanket, and furthermore, It is preferable in that it can be easily impregnated into the inside. In the case where the component containing Ca is precipitated in the oxide precursor containing solution, the inorganic fiber can not be uniformly coated on the surface of the inorganic fiber, so that a portion not coated on the surface of the fiber is formed and erosion due to scale may occur therefrom , The effect of improving the scale resistance can not be sufficiently exhibited.

Specific examples of the component containing Al include hydroxides, chlorides, acetates, lactates, nitrates, carbonates and the like of aluminum. These may be contained in the oxide precursor-containing liquid alone or in two or more species. Among them, aluminum acetate, hydroxide or carbonate is preferable because it is mainly water and carbon dioxide and does not deteriorate a metal member, a steel sheet or the like in the furnace.

The component containing Al may be dissolved in the oxide precursor containing liquid, may be in the form of a naphtha, or may be in a dispersed phase. Since the component containing Al is dissolved or uniformly dispersed in the oxide precursor containing liquid, the oxide precursor can be uniformly coated on the entire surface of each inorganic fiber constituting the needle blanket, and furthermore, It is preferable in that it can be easily impregnated into the inside. When the component containing Al is precipitated in the oxide precursor containing solution, the inorganic fiber surface can not be uniformly coated on the surface of the inorganic fiber, so that a portion not coated on the surface of the fiber is formed and erosion due to scale may occur therefrom , The effect of improving the scale resistance can not be sufficiently exhibited.

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

As the component for generating CaO by the calcination used in the case of using the alumina sol, calcium acetate is preferable. By mixing the acetate salt, the lowering of the dispersibility of the alumina sol can be suppressed and the viscosity of the oxide precursor-containing liquid can be prevented from increasing. When the viscosity of the oxide precursor-containing liquid is within an appropriate range, it is easy to impregnate and to control the deposition amount easily. When the viscosity of the oxide precursor-containing liquid is excessively high, impregnation with the 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-mentioned Al-containing component and Ca-containing component such that the molar ratio (Al / Ca) of Al to Ca is 4 or more and 100 or less, 6 or more and 36 or less, particularly preferably 9 or more and 13 or less. When the Al / Ca ratio is within this range, it is possible to prevent the calcium component from diffusing properly and reacting the scale with the inorganic fibers when heated in the furnace. In addition, since the calcium oxide-based oxide having high scaling property is produced, 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 generates Al ₂ O ₃ by firing and the component that generates CaO by firing) is preferably from 2 to 30 mass%, more preferably from 2 to 30 mass% By mass to 5% by mass to 10% by mass. If the oxide precursor concentration of the oxide precursor-containing liquid is too low, there is a fear that the amount of deposition (deposition amount) of the oxide precursor component to the needle blanket is lowered. In addition, if the oxide precursor concentration of the oxide precursor-containing liquid is too high, the viscosity of the oxide precursor-containing liquid tends to be high, and impregnation may be difficult.

As described above, the oxide precursor-containing liquid is preferably a sol or a solution because it is possible to uniformly coat the surface of each inorganic fiber of the needle blanket with an oxide precursor.

As the dispersion medium or the solvent of the oxide precursor-containing liquid, water, an organic solvent such as an 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 enhance stability of the sol or the compound in the solution. Examples of the dispersion stabilizer include acetic acid, lactic acid, hydrochloric acid, nitric acid, sulfuric acid and the like.

The oxide precursor-containing liquid may be mixed with a coloring agent. It is preferable that the oxide precursor-containing liquid is colored so that the areas of the impregnated portion and the non-impregnated portion of the needle blanket can be visually confirmed. The colored color is preferably black or blue. As the coloring agent, a water-soluble ink or the like can be used.

The preferred amount of impregnation of the oxide precursor-containing liquid to the needle blanket is as described below.

[Method of impregnating oxide precursor-containing liquid]

In order to impregnate the needle precursor-containing liquid with the needle blanket of the inorganic fiber, the needle blanket may be immersed in the oxide precursor-containing liquid to penetrate the inorganic precursor-containing liquid between the inorganic fibers of the needle blanket.

After impregnating the needle precursor-containing liquid with the needle precursor-containing liquid, the surplus liquid may be desorbed by suction or compression, if necessary, so as to have a desired water content and an oxide precursor adhered amount. In order to desorb surplus liquid by suction, it is preferable to mount an attachment to be placed on the impregnation portion, and suck it from the suction port formed in the attachment to desorb the liquid.

In this way, the oxide precursor-containing liquid may be impregnated, and if necessary, the excess liquid may be desorbed, and further dried to a predetermined water content as necessary. By doing so, it is possible to reduce the water content while maintaining the high oxide precursor adhesion amount (deposition amount). By reducing the water content, adhesion with the adhesive at the time of construction can be improved. In addition, there is an advantage in that the ease of construction is facilitated by reducing the mass of the inorganic fiber formed body while maintaining the flexibility. The drying conditions are suitably set in the range of from 80 to 180 DEG C for 0.5 to 24 hours depending on the amount of moisture to be desorbed.

The adhered amount of the oxide precursor-containing liquid is preferably ₂ to 50 parts by mass relative to 100 parts by mass of the inorganic fibers as an oxide (CaO and Al ₂ O ₃ ) converted amount as described later.

[Position of the impregnating portion in the needle blanket]

The heat insulating protective member for a skid post of the present invention is characterized in that at least a part of the needle blanket of the inorganic fiber is impregnated with an oxide precursor-containing liquid and is in an undried state (hereinafter simply referred to as & &Quot; in some cases).

It is preferable that the impregnating portion is formed on the exposed surface (exposed surface) of the heat insulating protective member for the skid post when the heat insulating protective member for the skid post is used in the heating furnace. This is because erosion due to scale occurs in the non-impregnated portion, and when all the exposed portions are the impregnated portion, the scale resistance can be enhanced.

The impregnation depth in the thickness direction of the blanket is preferably at least 3 mm from the blanket surface which is at least the exposed surface in the furnace, more preferably 10 mm or more. When the impregnation depth is equal to or more than the above lower limit, the inner scale property is improved. An embodiment in which the needle blanket is impregnated over the entire thickness is preferable because the scale resistance is most improved.

It is preferable that the impregnating portion is formed continuously over at least a half or more of the plate surfaces of the plate-like needle blanket, and the impregnating portion is formed over the entire thickness of the needle blanket in the region where the impregnating portion is formed.

In particular, it is preferable that the impregnating portion is formed on both the front and back surfaces of the plate surface of the plate-like needle blanket. More preferably, the impregnated 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 impregnated portion on the surface of the ring- In a range of 20 to 50% of the thickness of the film. Particularly preferably, the impregnating portion is formed over the entire thickness.

[Water content of the impregnated portion and the heat insulating protective member for the skid post]

In the heat insulating protective member for a skid post of the present invention, the moisture content of the impregnated portion is 50 to 400 parts by mass with respect to 100 parts by mass of the inorganic fibers of the impregnated portion. When the moisture content of the impregnation portion is excessively small, the flexibility is lost due to the binder effect. In addition, the generation of dust in the fibers is also increased. On the other hand, when the water content of the impregnated portion is excessively large, only a slight pressure is applied to the inorganic fiber formed body, and the liquid leaks from the inorganic fiber. In addition, there is a problem that the inorganic fiber formed body is crushed due to its own weight, and therefore the peeling of the end face becomes large. If the moisture content of the impregnation portion is too large, migration of the sol due to drying of the water, which is referred to as migration due to heating at the time of use, occurs to a great extent and the amount of deposition near the drying surface is significantly increased, , The thermal shock resistance and the heat shrinkage ratio are deteriorated. That is, in order to maintain the uniformity of the entire impregnated portion, it is important that the water content of the impregnated portion does not exceed 400 parts by mass. Preferably, the moisture content of the impregnating portion is 80 to 350 parts by mass based on 100 parts by mass of the inorganic fibers of the impregnating portion.

The amount of water contained in the entire heat insulating protective member for a skid post of the present invention is 50 to 400 parts by mass based on 100 parts by mass of the inorganic fibers in the entire heat insulating protective member for a skid post. If the moisture content of the heat insulating protective member for the skid posts is less than 50 parts by mass based on 100 parts by mass of the inorganic fibers, it is difficult to keep the heat insulating protective member for the skid posts in an unfired state and the flexibility is lowered, . If the moisture content of the heat insulating protective member for the skid post is more than 400 parts by mass based on 100 parts by mass of the inorganic fibers, the liquid leaks from the inorganic fibers merely by applying a slight pressure to the heat insulating protective member for the skid posts. In addition, there is a problem that the heat insulating protective member for a skid post is crushed by its own weight, and therefore, the end face peeling becomes large. The water content of the entire heat insulating protective member for a 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 a skid post.

[Adhesion amount of oxide after firing]

The oxide precursor-containing liquid is a solution in which the amount of oxide (CaO and Al ₂ O ₃ ) deposited after firing (hereinafter simply referred to as "oxide deposition amount") in the impregnation portion is 2 to 50 And the needle blanket is impregnated with a mass. The 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 of the impregnation portion. When the oxide deposition amount is small, the desired scale resistance may not be obtained. On the other hand, if the amount is too large, the density of the impregnation portion is increased, deterioration of heat shrinkage rate, thermal shock resistance and mechanical shock resistance are reduced. When the calcium component is present in a large amount on the surface of the fiber, the calcium component and the inorganic fiber generate a large amount of the low melting point component, so that the heat resistance of the impregnated portion is lowered.

The amount of oxide adhering to the entire heat insulating protective member for a skid post is preferably from 5 to 40 parts by mass, particularly from 8 to 30 parts by mass, based on 100 parts by mass of the inorganic fibers in the entire heat insulating protective member for a skid post desirable.

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

The whole impregnated portion refers to the entirety of the inorganic fibers and the adhered matter constituting the impregnated portion. The molar ratio (Al / Ca) of Al to Ca in the entire impregnation portion is determined by the molar amount of Al contained in the inorganic fibers constituting the needle blanket existing in the impregnation portion of the inorganic fiber compact, Is the ratio of the sum of the molar amount of Ca contained in the inorganic fibers to the molar amount of Ca derived from the oxide precursor containing liquid. The molar ratio (Al / Ca) of Al to Ca is substantially the same as that of the heat insulating protective member for skid posts before the application and the heat insulating protective member for the skid post which is fired by heating after application.

The molar ratio of Al: Si: Ca in the entire impregnation portion of the heat insulating protective member for a skid post of the present invention is preferably from 77.2 to 79.5: 18.9 to 21.6: 0.9 to 2.2 in view of the scaling resistance, heat resistance and thermal shock resistance. Here, the molar amount of Al and the molar amount of Ca in the whole impregnation portion are determined by the respective molar amounts of Al and Ca contained in the inorganic fibers constituting the needle blanket existing in the impregnation portion and the molar amount of Al derived from the oxide precursor- And Ca, respectively. The molar amount of Si is the molar amount of Si contained in the inorganic fibers constituting the needle blanket.

The amounts of Al, Ca, and Si in the impregnation portion can be measured by fluorescent X-ray analysis.

[Action of CaO]

When the heat insulating protective member for a skid post of the present invention having an impregnation portion is heated in the furnace and the oxide precursor containing liquid is baked at a high temperature, a part of the CaO component produced from the oxide precursor containing liquid diffuses into the inorganic fibers. Since the molar ratio (Al / Ca) of Al to Ca in the entire impregnation portion is in the above range, an appropriate amount of CaO diffuses into the inorganic fibers when fired to a high temperature. The presence of an appropriate amount of CaO in the inorganic fibers makes it difficult for FeO to diffuse into the inorganic fibers. That is, the reaction of inorganic fibers with FeO is suppressed. Therefore, the inner scale of the heat insulating protective member for a skid post is improved. When the molar ratio (Al / Ca) of Al to Ca in the impregnated portion is less than 10, since a large amount of a low melting point compound with inorganic fibers is formed by the inorganic fibers and CaO diffused therein, , There is a fear that the thermal shock resistance is lowered. Further, when the molar ratio (Al / Ca) of Al to Ca in the impregnation portion is more than 330, the diffusion of CaO is insufficient and there is a fear that the inner scale is not improved. In particular, mullite _{(3Al 2 O 3 · 2SiO 2} ) the case of using the inorganic fibers of the composition, upon baking at a high temperature, this diffusion is a CaO in the mullite crystalline phase and a mullite crystal phase components are generated. In this case, it is considered that the FeO property is improved because CaO is diffused into the fiber while leaving a mullite crystal phase excellent in thermal shock resistance, heat resistance and mechanical shock resistance.

This, the inorganic fiber molded body 1400 ℃, after calcination for 8 hours, an X-ray diffraction peak which is detected by (XRD), showing a mullite crystal phase showing a peak and a CaO-Al ₂ O ₃ -SiO ₂ type crystal phase Can be confirmed by the presence of a peak.

The fact that the Ca component diffuses into the fibers can be confirmed by element mapping using an electron beam microanalyzer (EPMA).

[Material of the blanket 40 to which an oxide precursor-containing liquid is adhered in an undried state]

As the blanket 40 to which the oxide precursor-containing liquid is adhered in an undried state, the above oxide precursor-containing liquid is added to the inorganic blanket of the inorganic fiber having a thickness of about 10 to 30 mm, By mass to 50% by mass.

Example

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples at all without departing from the gist thereof.

[Example 1]

A needle blanket having an average fiber diameter of 5.5 占 퐉 and containing no fibers having a fiber diameter of 3 占 퐉 or less and polycrystalline alumina / silica fibers containing 72% by mass of alumina and 28% 390 ㎜ (Mitsubishi Chemical Co., Ltd. trade name MAFTEC ^TM MLS, thickness 25 ㎜, needle traces density five strokes / ㎠, a bulk density of 128 ㎏ / ㎥ (0.128 g / ㎤), surface density of 3200 g / ㎡) the outer diameter (diameter), And then punched into a donut shape having an inner diameter (diameter) of 270 mm to produce a ring-like needle blanket 10.

In the ring-type needle blanket 10, the residual surface pressure ratio after the cycle test under the conditions described below was measured. As a result, the residual surface pressure ratio was 33%.

The ring-type needle blanket 10 after sintering at 1400 占 폚 for 12 hours was compressed to GBD (bulk density) = 0.195 (g / cm3) by a tensile compression tester (manufactured by Minebea Co., Ltd.) (g / cm 3) to 0.24 (g / cm 3) was repeated 100 times. At this time, the open side surface pressure value at GBD = 0.20 (g / cm 3) and the open side surface pressure value at GBD = 0.24 (g / cm 3) at the 100th time were measured, The residual surface pressure ratio (%), which is an index of the deterioration degree of the surface pressure, was obtained.

Remaining surface pressure ratio = 100th open surface pressure / first open surface pressure

Further, in the ring-type needle blanket 10, the heat shrinkage ratios in the width direction, the longitudinal direction and the thickness direction after firing at 1400 DEG C for 12 hours were measured in accordance with JIS R3311 (details are given below) 0.4% in the longitudinal direction, 0.4% in the longitudinal direction, and 0.0% in the thickness direction.

Condition: The ring-like needle blanket 10 was cut into a length of about 150 mm and about 100 mm to obtain a test piece. The test piece was embedded with a back surface wire in a rectangular shape of about 120 mm × about 60 mm. And the mixture was fired in an atmosphere heated to a temperature of 1400 DEG C for 12 hours. The heating wire shrinkage percentage was calculated by the following formula.

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

Using this ring-type needle blanket 10, the skid pipe 1 having a diameter of 270 mm was constructed by the procedure of Figs. The height H from the hearth G to the lower end of the refractory sheath 3 is 1800 mm.

The length of the ring-like needle blanket of each of the compression layers L-1 to L-3, the height dimension after compression, and the compression ratio are as follows.

L-1: 27 sheets, height after compression of 600 mm, compressibility of 10%

L-2: 28 sheets, height after compression of 600 mm, compression rate of 12%

L-3: 26 sheets, height after compression (T = 560 mm), compression rate 15%

The gap height h between the third stage pressure plate 20 and the refractory sheath 3 is 20 mm and after one ring type needle blanket 10 is mounted thereon, all the pressure plates 20 are taken out, State. The average bulk density of L-1, L-2 and L-3 (but including the top ring type needle blanket 10) and the uppermost ring type needle blanket 10 are located at the lower end of the refractory sheath 3 (Inter-surface pressure) was measured. The results are shown in Table 1.

[Example 2 (further compressing the third compression layer)]

The same construction as in Example 1 was carried out except that the number of ring-shaped needle blanket in the third compression layer (L-3) was 28, the compression height was 560 mm, and the compression ratio was 20%. The average bulk density and inter-surface pressure of L-1, L-2 and L-3 (but including the top ring type needle blanket 10) were measured. The results are shown in Table 1.

[Comparative Example 1]

The compression ratio of the third compression layer L-3 was made equal to that of the first and second compression layers L-1 and L-2. That is, the same construction as in Example 1 was carried out except that the number of ring-shaped needle blanket lengths of the third compression layer (L-3) was 25, the compression height was 560 mm, and the compression ratio was 10%. The average bulk density, and the interplanar pressure, of L-1, L-2 and L-3 (including the top ring type needle blanket 10) were measured. The results are shown in Table 1. Which was lower than those of Examples 1 and 2.

[Example 3]

A ring-shaped needle blanket (10) laminated compact having the same compression ratio as in Example 1 was prepared. Mortar was applied to the surface to a thickness of about 3 mm. To the alumina sol solution containing acetic acid as a dispersant, calcium acetate monohydrate was added And a blanket impregnated with a solution containing an oxide precursor in the entire thickness direction in which the solid content concentration in terms of oxide was adjusted to 7.0% by mass (a water content of 200 parts by mass relative to 100 parts by mass of inorganic fibers) , 18 parts by mass (in terms of oxide) of the oxide precursor adhered to 100 parts by mass of the inorganic fibers, a molar ratio (Al / Ca) of Al to Ca in the impregnation portion of 64, and a bulk density of 0.41 g / cm3) were wound. The blanket 40 on the surface was opened with a cutter knife and the blanket 40 was peeled off to form a ring-shaped needle blanket 10 laminated body 10 The inorganic fibers derived from the blanket 40 adhered to the entire surface of the laminated needle blanket 10 laminate press.

[Comparative Example 2]

Mortar was applied to the surface of the amorphous 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 baked at a heating rate of 5 ° C / min and at 1400 ° C for 12 hours. The inorganic fiber compact on the surface was opened with a cutter knife. The blanket 40 was peeled off and the surface of the amorphous refractory was visually observed. The inorganic fibers derived from the blanket 40 adhered only to a part of the surface of the needle blanket 10 laminated press.

[Review]

The ring-type needle blanket used in the embodiment has a constant surface pressure capable of enduring long-term vibration in a harsh environment because the residual surface pressure ratio after the cycle test after firing (1400 DEG C, 12 hours) is 10% or more. Further, the ring-type needle blanket used in the examples had a good linearity at high temperature stability by using a ring-type needle blanket having a heating linear shrinkage ratio of 1% or less in the width direction, the longitudinal direction and the thickness direction after firing (1400 DEG C for 12 hours) . Accordingly, when the ring-type needle blanket used in the embodiment is compressed and evaluated, the bulk density of the compression layer is divided into three parts, that is, the upper part, the middle part and the lower part in the height direction, It is contemplated that by increasing the volume density in comparison with the volume density in the lower portion, the surface pressure can be kept constant in a harsh environment to withstand long-term vibration and the influence of shrinkage due to firing can be suppressed. On the other hand, in Comparative Example 1, since the compressibility is low, it is estimated that the initial surface pressure is low and a gap is formed.

The comparison between Example 3 and Comparative Example 2 shows that the adhesion of the inorganic fiber molded body to the ring-shaped needle blanket 10 laminated body is better when the adhesion between the blanket 40 and the layered body 10 of the ring- It can be seen that it is high. This is because the blanket 40 and the layered body 10 of the ring-shaped needle blanket are made of the same material, so that there is no difference in shrinkage due to the material, and the oxide precursor- 10 and the oxide precursor at the interface of the blanket 40 and the layered body 10 of the ring-shaped needle blanket becomes an oxide when the oxide precursor is converted to oxide at firing, Is thought to function as an adhesive between the blanket 40 and the layered body 10 of the ring-type needle blanket. 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 ratio due to the material of the blanket 40 and the irregular refractory material, and the space is gradually widened when the space is formed. The adhesion is easily reduced. In the adiabatic protecting member according to the present invention, it is possible to suppress the reduction of adhesion with the blanket 40 impregnated with the oxide precursor-containing liquid.

While the invention has been described in detail with reference to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and 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, which is incorporated by reference in its entirety.

1: skid pipe, 2: skid beam, 3: refractory sheath, 4: anchor metal insert, 10: ring type needle blanket, 20: press plate, 21, 22: press plate half, 30: anchor fitting,

Claims (12)

A method for constructing a heat insulating protective member below a refractory sheath of a skid pipe having a refractory sheath on the upper side,
A plurality of inorganic fiber ring type needle blanket are extrapolated to the skid pipe to form an impact body,
Subsequently, the step of pressing the pressed body with the push plate from above to form a compressed layer is repeated a plurality of times to form first to n-th compressed layers (where n is an integer of 2 or more)
The ring-shaped needle blanket is extrapolated between the compression layer at the uppermost stage and the lower end surface of the refractory sheath, and then the press plate is removed to restore the weight, so that the ring- A method of constructing a heat insulating protective member to be pressed,
When the bulk density of the compressed layer is evaluated by dividing the volume density into three equal parts in the height direction, upper, middle and lower, the bulk density at the upper part is higher than the bulk density at the middle part and lower part. A method of constructing a heat insulating protective member of a pipe. The method as claimed in claim 1, wherein the upper compression layer has a bulk density of 1.1 to 3.0 times the bulk density of the middle and lower compression layers. The method of claim 1 or 2, wherein the bulk density in the center portion is higher than the bulk density in the lower portion. The method as claimed in any one of claims 1 to 3, wherein the upper compression layer has a bulk density of 0.10 g / cm3 or more and 0.20 g / cm3 or less. 5. The heat insulating protective member of a skid pipe according to any one of claims 1 to 4, wherein the inorganic fiber ring type needle blanket has a residual surface pressure ratio of 10% or more after the cycle test under the conditions described below Construction method.
Condition: The ring-type needle blanket after firing at 1400 占 폚 for 12 hours was compressed to GBD (bulk density) = 0.195 g / cm3 by a tensile compression tester and then the upper and lower plates were compressed from GBD = 0.20 g / cm3 to 0.24 g / I repeated the thing 100 times. At that time, the open side surface pressure value at GBD = 0.20 g / cm &lt; 3 &gt; at the first time and the open side surface pressure value at GBD = 0.24 g / (%) Which is an index of the residual surface pressure ratio.
Remaining surface pressure ratio = 100th open surface pressure / first open surface pressure 100 The inorganic fiber ring type needle blanket according to any one of claims 1 to 5, wherein the heat shrinkage ratio in the width direction, the longitudinal direction and the thickness direction after firing at 1400 캜 for 12 hours is 1% or less Wherein the method comprises the steps of: 7. The apparatus according to any one of claims 1 to 6, wherein the ring-shaped needle blanket is formed with a slit in the radial direction,
And the ring-shaped needle blanket is extruded into the skid pipe by opening the slit. 8. The method according to claim 7, wherein the slit of the ring-shaped needle blanket is shifted in the circumferential direction so as not to overlap each other. 9. The method according to any one of claims 1 to 8, wherein an anchor-metal fitting portion is formed in the skid pipe,
And an anchor bracket for preventing the upward movement of the pressure plate is engaged with the anchor bracket insertion portion to prevent the upward movement of the pressure plate. 10. The method of claim 9, wherein the anchor bracket has a pin projecting upward and downward, and the pin is pierced through the ring-like needle blanket superimposed on the presser plate. 11. The method according to any one of claims 1 to 10, wherein a blanket having an oxide precursor-containing liquid adhered in an undried state is wound around the outer periphery of the ring-shaped needle blanket, and the oxide precursor- Wherein the alumina / calcia-based composition comprises aluminum oxide and calcium oxide by firing to produce an alumina / calcia-based composition. A skid pipe with a heat insulating protective member with a heat insulating protective member formed below the refractory sheath of a skid pipe having a refractory covering on the upper part,
Wherein the heat insulating protective member is a heat insulating protective member attaching skid pipe having an impact body of a ring-shaped needle blanket extruded into a skid pipe and pressed by the uppermost ring-shaped needle blanket by the repulsive force of the impact body ,
When the weight is evaluated by dividing into three equal parts in the height direction in the height direction, the bulk density of the ring-like needle blanket at the upper portion is higher than the bulk density of the ring-shaped needle blanket at the center portion and the lower portion Wherein the skid pipe is provided with the heat insulating protective member.

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