JP2012177463A - Cylindrical heat insulation material, and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical heat insulation material which thermally insulates a high-temperature thermal device body by utilizing high heat insulation property of silica aerogel particles and achieving reduction in thickness or size, and to provide a method for manufacturing the same.SOLUTION: This cylindrical heat insulation material 1 is inserted and attached to a thermal device body A to thermally insulate the thermal device body A, and is composed of a calcium silicate compact internally formed with a plurality of fine pores which have porosity of 50% or higher and are composed of the silica aerogel particles densely blended. The method for manufacturing the cylindrical heat insulation material uses silica aerogel raw material with a hydrophilic coating film formed on surfaces of hydrophobic silica aerogel particles as the silica aerogel particles, the hydrophobic silica aerogel particles being treated to prevent intrusion of water into the inside.

Description

The present invention relates to a cylindrical heat insulating material that insulates a high-temperature heat device main body such as a reformer main body of a fuel cell.

As a thermal equipment body that needs to insulate the thermal equipment body in a thermal equipment that generates heat at a high temperature, there is a reformer body of a fuel cell, and as a thermal insulation material that insulates such a thermal equipment body, insulation is sufficient. Therefore, it is desired to make it thinner or more compact and to improve the efficiency of workability to be arranged in the main body of the thermal equipment. For this purpose, various cylindrical heat insulating materials for inserting the thermal equipment main body have been proposed.

For example, as in Patent Document 1, a cylindrical heat insulating material formed by coating a heat insulating layer of a compression molded body using inorganic nanoparticles such as silica (silica nanoparticles) with a coating layer of a cylindrical molded body, As in Patent Document 2, a cylindrical heat insulating material made by filling a hollow part of a hollow molded body made of inorganic fibers with a filler made of inorganic powder such as silica, and further, as in Patent Document 3, Cylindrical heat insulating materials made by sequentially laminating a flexible inorganic heat insulating material, a flexible airgel heat insulating material, and a flexible inorganic heat insulating material have been proposed.

JP 2009-299893 A JP 2007-1000075 A JP 2010-33745 A

However, in the cylindrical heat insulating materials proposed in Patent Documents 1, 2, and 3, all of the inorganic nanoparticles, the inorganic powder, and the airgel heat insulating material excellent in heat insulating properties are formed separately from other heat insulating materials. ing. Therefore, since these inorganic nanoparticles, inorganic powder, and airgel heat insulating material excellent in heat insulation will insulate the heat equipment body through other heat insulating materials, the inorganic nanoparticles, inorganic powder, and airgel heat insulating material Thermal insulation is not sufficiently utilized, and there is a limitation as a cylindrical heat insulating material that can insulate a high-temperature thermal equipment body and reduce the thickness.

Furthermore, in the cylindrical heat insulating material proposed in Patent Document 1, the end of the covering sheet is adhered to form a cylindrical bag so that inorganic nanoparticles (silica nanoparticles) do not generate dust, or the covering layer is doubled. Work process is necessary. Moreover, in the cylindrical heat insulating material proposed in Patent Document 2, it is necessary to consider that the inorganic powder filled in the hollow portion is not scattered when the hollow molded body is damaged. Moreover, in the cylindrical heat insulating material proposed in Patent Document 3, it is necessary to work to closely adhere or laminate the heat insulating materials.

The present invention provides a cylindrical heat insulating material that eliminates the above-mentioned problems, makes a high-temperature heat equipment body heat-insulating by utilizing the high heat insulating property of silica airgel particles, and is made thin or compact, and a method for manufacturing the same. With the goal.

The cylindrical heat insulating material according to claim 1 is a calcium silicate molding in which a plurality of fine pores having a porosity of 50% or more are inserted inside the thermal equipment body to insulate the thermal equipment body and have a porosity of 50% or more. A heat insulating material made of a body is characterized in that the pores are made of silica airgel particles. Furthermore, the cylindrical heat insulating material according to claim 2 is the cylindrical heat insulating material according to claim 1, wherein the average particle diameter of the silica airgel particles is 1.5 mm. The cylindrical heat insulating material according to claim 3 is the cylindrical heat insulating material according to claim 1 or 2, wherein the calcium silicate compact is formed by adding an inorganic fiber filler to a powdered silicic acid raw material and a powdered calcium raw material. It is characterized by that. According to a fourth aspect of the present invention, there is provided a cylindrical heat insulating material obtained by coating the cylindrical heat insulating material according to any one of the first to third aspects with an inorganic fiber cloth.

The manufacturing method of the cylindrical heat insulating material according to claim 5 has a large number of fine pores having a porosity of 50% or more in a cylindrical shape that is inserted into the heat device main body to insulate the heat device main body. Silica airgel raw material and powdered silicic acid in which a hydrophilic coating is formed on the surface of hydrophobic silica airgel particles treated so as to prevent water from penetrating into the heat insulating material made of calcium silicate molded body The slurry obtained by mixing the raw material, the powdered calcium raw material, and water and mixing the silica airgel particles in the powdered silicic acid raw material and the powdered calcium raw material in a cylindrical shape is dehydrated and formed into a primary molded product, It is characterized in that the pores of the calcium silicate molded body are composed of silica airgel particles by forming the calcium silicate molded body solidified by steam curing and drying the primary molded product. To. Furthermore, the manufacturing method of the cylindrical heat insulating material according to claim 6 is a method in which an inorganic fiber filler is added to the powdered silicic acid raw material and the powdered calcium raw material according to the manufacturing method of the cylindrical heat insulating material according to claim 5. A slurry obtained by stirring and mixing water-like hydrophilic silica airgel raw material and water is dehydrated into a cylindrical shape to form a primary molded product. The method for manufacturing a cylindrical heat insulating material according to claim 7 is the method for manufacturing a cylindrical heat insulating material according to claim 5 or 6, wherein the slurry is dehydrated into a cylindrical shape with an inorganic fiber cloth arranged. It is characterized by forming a primary molded product.

By the cylindrical heat insulating material according to claims 1 and 2 and the manufacturing method of the present invention and the method for manufacturing the same, the cylindrical heat insulating material is inserted into the thermal equipment body to insulate the thermal equipment body, and the porosity is 50% or more. In the heat insulating material made of a calcium silicate molded body having a large number of fine pores inside, the pores are made of silica airgel particles, so that the silica airgel particles are intimately mixed and a large amount of silica airgel particles By using the calcium silicate molded body made of the above, it is possible to insulate the high-temperature heat equipment body that effectively utilizes the heat insulation property of the silica airgel, and to provide a thin or compact cylindrical heat insulating material. Furthermore, according to the cylindrical heat insulating material according to claim 3 and claim 6 and the manufacturing method thereof, the calcium silicate molded body is made by adding an inorganic fiber filler to a powdered silicate raw material and a powdered calcium raw material, The strength can be increased, and the cylindrical heat insulating material according to claim 4 and claim 7 and the method for producing the same are formed by covering the cylindrical heat insulating material with inorganic fiber cloth. Compositions such as silicic acid raw material, powdered calcium raw material and silica airgel raw material, in particular, effects such as providing a cylindrical heat insulating material that prevents silica airgel particles from adhering to equipment and workers in transportation work and insertion work There is.

It is sectional drawing of the state which inserted and attached the cylindrical heat insulating material which shows embodiment of this invention to the heat equipment main body. It is sectional drawing of the cylindrical heat insulating material which shows embodiment of this invention. It is sectional drawing which decomposed | disassembled the cylindrical heat insulating material of FIG. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is CC sectional drawing of FIG. It is a flowchart which shows the manufacturing process of a cylindrical heat insulating material same as the above. It is sectional drawing of the slurry formation apparatus used for manufacture of a cylindrical heat insulating material same as the above. It is sectional drawing of the shaping | molding apparatus used for manufacture of a cylindrical heat insulating material same as the above. It is DD sectional drawing of FIG. It is EE sectional drawing of FIG. It is sectional drawing which coat | covered the inorganic fiber cloth on the upper mold | type and lower mold | type of the shaping | molding apparatus of FIG. It is sectional drawing which shows the state which closed the upper mold | type and lower mold | type of the shaping | molding apparatus of FIG. It is sectional drawing which shows the state filled with the slurry with the shaping | molding apparatus of FIG. It is sectional drawing which shows the state which shape | molded in FIG. 14 and opened the upper mold | type and the lower mold | type. FIG. 16 is a cross-sectional view showing a state where a cylindrical heat insulating material is manufactured by opening the upper mold and the lower mold in FIG.

Embodiments of the tubular heat insulating material of the present invention will be described below with reference to the drawings.

(Embodiment of thermal equipment main body)
FIG. 1 illustrates a cylindrical steam reformer for a fuel cell described in Japanese Patent Application Laid-Open No. 2010-161047 (hereinafter referred to as “exemplary publication 1”) as a thermal device that generates heat at a high temperature, and simplified heat illustrated. In embodiment of an apparatus main body, it is sectional drawing of the state which inserted and attached the cylindrical heat insulating material to the thermal apparatus main body. In FIG. 1 and FIG. 6 of this Illustrative Publication 1, the reformer body has a small-diameter cylindrical body in which a reforming catalyst layer having a temperature reaching about 700 ° C. is disposed, a CO shift catalyst layer having a temperature of 300 to 330 ° C., and 170 It consists of a large-diameter cylindrical body on which a CO removal catalyst layer having a temperature of about 0 ° C. is disposed, and consists of a heat-insulating material layer made of powdered fumed silica that fills the outer periphery of the small-diameter cylindrical body and this powdered fumed silica. Although the ceramic fiber-based heat insulating material layer disposed on the outer periphery of the heat insulating material layer and the large-diameter cylindrical body is disposed, in the embodiment of the present invention, the small-diameter cylindrical body and the large-diameter cylindrical body are simplified. A heat source body A having the same diameter and a cylindrical shape is used, and a raw fuel supply pipe, a CO removal air supply pipe, a water supply pipe, a water vapor supply pipe, a combustion exhaust gas discharge pipe, a reformed gas outlet pipe, etc. are simplified as a pipe A1. Yes.

In order to insulate such a high-temperature heat device main body A, the tubular heat insulating material 1 having one end having a peripheral wall 1A, a top wall 1B, and a space 1C is inserted into the heat device main body A. Although the cylindrical heat insulating material 1 is illustrated as a cylindrical body having the same diameter, if the heat equipment main body A is composed of a small diameter cylindrical body and a large diameter cylindrical body, the tubular heat insulating material 1 is used as the heat equipment. A small-diameter cylindrical body and a large-diameter cylindrical body may be used in accordance with the shape of the thermal apparatus main body A so that it can be inserted into the main body A. In this case, the thermal apparatus main body A may be a cylinder having a perfect circle or a non-circular cross section, or may be a cylinder having a rectangular cross section, so that the cylindrical heat insulating material 1 corresponds to the shape of the thermal apparatus main body A. And a cylinder with a perfect circle or a non-perfect circle may be sufficient as a cross section, and a cylinder with a rectangular cross section may be sufficient.

The pipe A1 protrudes outward from one end (the lower end in FIG. 1) of the thermal equipment main body A. However, if the thermal equipment main body A projects outward from the peripheral wall (left and right in FIG. 1), the pipe A1 is tubular. The heat insulating material 1 is provided with holes (not shown) formed in the peripheral wall 1A in advance by drilling, and the cylindrical heat insulating material 1 is inserted into the thermal apparatus main body A without the pipe A1, and then the peripheral wall You may make it attach the pipe A1 to the thermal equipment main body A through the hole formed in 1A.

Since this cylindrical heat insulating material 1 is made of a calcium silicate molded body composed of a large amount of silica airgel particles, the silica airgel particles are prevented from adhering to devices and workers in transportation work and insertion work. In addition, it is desirable to coat the outer peripheral surface and the inner peripheral surface of the cylindrical heat insulating material 1 with inorganic fiber cloths 2 and 3, respectively, and it is sufficient to have a mesh smaller than the particle size of these compositions. These inorganic fiber cloths 2 and 3 may not be used as the state of the calcium silicate molded body.

(Embodiment of cylindrical heat insulating material)
2 to 6 show an embodiment of a cylindrical heat insulating material covered with inorganic fiber cloths 2 and 3. In FIG. 2, the cylindrical heat insulating material 1 is a cylindrical body having a peripheral wall 1 </ b> A, a top wall 1 </ b> B, and a space 1 </ b> C that is open at one end (opened in FIG. 2) and uniformly contains silica airgel particles throughout. It is made of a calcium silicate molded body, and the space 1C is formed in a size and a shape that can be inserted into close contact with the outer periphery of the thermal equipment main body A. The calcium silicate molded body contains silica airgel particles, but an inorganic fiber filler such as glass fiber may be added to increase the strength.

Since the cylindrical heat insulating material 1 is made of a calcium silicate molded body containing silica airgel particles, the cylindrical heat insulating material 1 is inserted into a high-temperature heat device main body such as a reformer main body of a fuel cell. In the inserted state, compositions such as powdered silicic acid raw material, powdered calcium raw material and silica airgel raw material, especially silica airgel particles may adhere to equipment and workers in transportation work and insertion work Therefore, in order to prevent the adhesion, it is desirable to coat the outer peripheral surface of the peripheral wall 1A and the top wall 1B or the inner peripheral surface and the open end surface of the peripheral wall 1A and the top wall 1B with an inorganic fiber cloth 3 such as glass fiber or silica fiber. .

3 to 6 show an embodiment in which the inorganic fiber cloths 2 and 3 are inserted into and covered with the tubular heat insulating material 1. The inorganic fiber cloth 2 is a hollow cylindrical body having one end opened with a space portion having a size corresponding to the outer diameter of the peripheral wall 1A, and the inorganic fiber cloth 3 has an outer diameter having a size corresponding to the inner diameter of the peripheral wall 1A. Is a hollow cylindrical body formed with an annular flange 3A protruding outward in a size corresponding to the thickness of the opening end (thickness of the peripheral wall 1A). By inserting the inorganic fiber cloth 2 formed in this way into the cylindrical heat insulating material 1 from the direction of the arrow P1, and inserting the inorganic fiber cloth 3 into the cylindrical heat insulating material 1 from the direction of the arrow P2, the peripheral wall 1A The outer peripheral surface of the top wall 1B is covered with an inorganic fiber cloth 2, and the inner peripheral surface and the opened end face of the peripheral wall 1A and the top wall 1B are covered with an inorganic fiber cloth 3. Further, the outer peripheral surface and inner peripheral surface of the cylindrical heat insulating material 1 are covered with inorganic fiber cloths 2 and 3, but only one of the outer peripheral surface and the inner peripheral surface of the cylindrical heat insulating material 1 is covered with inorganic fibers. You may coat with cloth 2 or 3. Furthermore, these inorganic fiber cloths 2 and 3 are inserted into and covered with the cylindrical heat insulating material 1, but the cylindrical heat insulating material 1 is molded as a calcium silicate molded body as shown in FIGS. When doing so, it may be integrated.

(Outline of manufacturing process)
FIG. 7 is a flowchart showing a manufacturing process of a cylindrical heat insulating material, showing an outline of the manufacturing process. First, in the slurry forming process 101, a large amount of raw materials composed of a powdered silicic acid raw material, a powdered calcium raw material, and a silica airgel raw material are used. In the molding step 102, a predetermined amount of the slurry S is injected into the dehydrating mold to form the primary molded product T, and then in the curing step 103 The primary molded product T is taken out from the dehydrating mold, and the cylindrical heat insulating material 1 is formed by subjecting it to autoclave (steam curing) treatment for a predetermined time, drying and solidifying. At that time, the slurry S is mixed with a silica airgel raw material having a hydrophilic coating formed on the surface of hydrophobic silica airgel particles treated so as to prevent water from penetrating into the slurry S, and has a cylindrical shape. The heat insulating material 1 is a cylindrical molded board made of a calcium silicate molded body composed of a large amount of silica airgel particles. In addition, you may add inorganic fiber fillers, such as glass fiber, to the said raw material.

(Manufacturing equipment and manufacturing method)
Next, with reference to FIG. 8 to FIG. 16, a method of manufacturing the tubular heat insulating material 1 made of a calcium silicate molded body containing silica airgel particles throughout will be described together with its manufacturing apparatus.

(Slurry forming process)
FIG. 8 shows a slurry forming apparatus in the slurry forming step 101, and a raw material in which a raw material consisting of a powdered silicic acid raw material, a powdered calcium raw material and a silica airgel raw material, and further an inorganic fiber filler raw material are added to the slurry housing case 4. And a large amount of water are contained so as to be kneaded. In this case, the powdered silicic acid raw material and the powdered calcium raw material or the powdered silicic acid raw material obtained by adding the inorganic fiber filler raw material to the raw material and the powdered calcium raw material contain a large number of fine pores having a porosity of 50% or more. The raw material is prepared by testing and confirming in advance the amount of the calcium silicate molded body having the above.

First, among the raw materials prepared by confirming to be a calcium silicate molded body having a large number of fine pores having a porosity of 50% or more, powdered silicic acid raw materials are quartz, silica, and silica sand. Etc. are made into a powder form with a particle size of 30 μm or less and an average particle size of about 2 to 3 μm. The powdered calcium raw material is calcium oxide, calcium hydroxide, quick lime, etc. The particle size is 30 μm or less and the average particle size is 2 The powdered silicic acid raw material and the powdered calcium raw material were approximately equal, and the powdered silicic acid raw material and the powdered calcium raw material or the inorganic fiber filler raw material was added to this raw material. Select powdered silicic acid raw material and powdered calcium raw material. A silica airgel raw material is blended with the selected powdered silicic acid raw material and powdered calcium raw material, or powdered silicic acid raw material obtained by adding an inorganic fiber filler raw material to this raw material and powdered calcium raw material. Silica airgel raw material corresponding to 1/2 to 1/6 by weight ratio of powdered silicic acid raw material and powdered calcium raw material or powdered silicic acid raw material obtained by adding inorganic fiber filler raw material to this raw material and powdered calcium raw material Is blended. In this case, the amount of the silica airgel raw material to be blended needs to aim at a calcium silicate molded body having a large number of fine pores having a porosity of 50% or more and make the pores become silica airgel particles. Therefore, the mixing weight ratio of the silica airgel raw material in the raw material composed of the powdered silicic acid raw material, the powdered calcium raw material and the silica airgel raw material or the raw material obtained by adding the inorganic fiber filler raw material to this raw material is based on the weight ratio exemplified above by test confirmation Re-set and select. The silica airgel raw material is a silica airgel particle having a cluster structure in which spherical fine particles are fused and having a porosity of 60% or more, and is treated so as to prevent water from entering the inside. The particles are made of silica airgel particles having a hydrophilic film formed on the surface thereof by treating the particles with a surfactant. The silica airgel particles have a particle size of 0.5 to 4 mm and an average particle size of 1.5 mm, which is larger than the particle sizes of the powdered silicic acid raw material and the powdered calcium raw material. Since the powdered silicate raw material and the powdered calcium raw material are easily blended between the airgel particles, the calcium silicate molded body has a large number of fine pores having a porosity of 50% or more, and the pores are silica airgel particles. It becomes easy to become.

Next, the raw material consisting of the selected powdered silicic acid raw material, powdered calcium raw material and silica airgel raw material or a raw material obtained by adding an inorganic fiber filler raw material to this raw material is 10 to 30 wt%, and the slurry containing casing 4 Then, it is mixed with 70 to 90% by weight of water, stirred and kneaded to obtain a viscous slurry S by a hydration reaction. In this case, the silica airgel raw material has an affinity for water on the surface of the hydrophobic silica airgel particles so that the water constituting the slurry S does not enter the interior and the cluster structure of the silica airgel particles is not destroyed. A large amount of water containing silica airgel particles is mixed with a powdered silicic acid raw material or a powdered calcium raw material and kneaded to obtain a slurry S in which silica airgel particles are closely mixed in the hydration process. .

In order to mix and stir and knead | mix the said raw material with a lot of water, the stirring jig 5 which stirs a raw material and water is used. The stirring jig 5 is provided with a blade 5A that is rotated by a prime mover (not shown) in one direction of the R direction or the reverse direction thereof, or alternately rotated in the R direction and the reverse direction. The raw material housed in the body 4 is stirred with water and kneaded and rotated until a slurry S having a predetermined viscosity is obtained by a hydration reaction. Thus, in order to confirm the viscosity of the slurry S in the course of the kneading action by the stirring jig 5, first, the powdered silicic acid raw material, the powdered calcium raw material and a large amount of water are accommodated, and these are stirred. It is preferable to supply the silica airgel raw material to the slurry containing housing 4 little by little while stirring with the jig 5. Since the silica airgel raw material has a hydrophilic coating formed on the surface of the hydrophobic silica airgel particles treated so as to prevent water from entering the inside, the powdered silicic acid raw material, the powdered calcium raw material and the water In the process of stirring and kneading, the silica airgel raw material is not lifted up or unevenly distributed in the slurry housing case 4, and the individual silica airgel particles of the silica airgel raw material are uniformly in the powdered silicic acid raw material and the powdered calcium raw material. Is blended into.

An inorganic fiber filler such as glass fiber having an average particle diameter of about several tens of μm may be added to the raw material composed of the powdered silicic acid raw material, the powdered calcium raw material, and the silica airgel raw material. In this case, a small amount of inorganic fiber filler is mixed in the slurry containing housing 4 in advance with a powdered silicic acid raw material and a powdered calcium raw material to contain a large amount of water. It is preferable to supply the airgel raw material to the slurry housing case 4 little by little. Thus, the intensity | strength of a calcium-silicate molded object can be made high by adding an inorganic fiber filler to a powdery silicic acid raw material and a powdery calcium raw material.

(Slurry molding process)
9 to 11 show a dehydrating mold of the molding apparatus in the slurry molding step 102. The molding apparatus 6 having the dehydrating mold includes an upper mold 9, a lower mold 10, a slurry supply member 7, a water absorbing member 12, and vibrations. The mechanism member 13 is comprised.

The upper mold 9 has a cylindrical wall 9A and a top wall 9B as shown in FIG. 10, and the lower mold 10 has a cylindrical body 10A and a base 10B as shown in FIG. Although the upper mold 9 and the lower mold 10 are opened and closed relatively, in this embodiment, the lower mold 10 is movable. Therefore, when the lower mold 10 moves in the direction of the upper mold 9 and closes, the upper mold 9 is moved. A space portion is formed as a dehydration mold portion 11 in which the top wall 9B and the base 10B of the lower die 10 are sealed with a seal member 14. The top wall 9 </ b> B of the upper mold 9 is formed with an inlet 9 </ b> D in which the nozzle portion 8 of the slurry supply member 7 communicates with the dehydration mold portion 11.

The water-absorbing member 12 has a pipe connected to the water-absorbing pump P, and a filter and a drainage sheet that can suck and dehydrate and deaerate by sucking moisture and air in the dehydrating mold part 11 can be attached to and detached from this pipe ( (Not shown). The pipe of the water absorbing member 12 is provided on the cylindrical wall 9A of the upper mold 9 so as to communicate with the dehydrating mold part 11 through a small hole formed in the cylindrical wall 9A of the upper mold 9. By driving the water absorption pump P of the water absorption member 12, the water and air of the slurry S filled in the dewatering mold part 11 are sucked and dehydrated and degassed to increase the viscosity of the slurry S to form powdered silicic acid. It has the effect of semi-curing so that the silica airgel particles are intimately mixed with a raw material comprising a raw material, a powdery calcium raw material and a silica airgel raw material or a raw material obtained by adding an inorganic fiber filler raw material to this raw material. Further, the water absorbing member 12 is provided on the cylindrical wall 9A of the upper mold 9 so that a plurality of water absorbing members 12 are, for example, three at intervals of 120 degrees and do not overlap in the direction of the cylindrical wall 9A. Is done efficiently.

The base 10B of the lower mold 10 is provided with a vibration mechanism member 13 so as to vibrate the lower mold 10 and the upper mold 9 with an amplitude of 0.01 to 2 mm at 6000 to 15000 times per minute. The vibration source of the vibration mechanism member 13 is exemplified by an ultrasonic oscillation device, but may be an electromagnetic vibration device. By driving the vibration mechanism member 13 to vibrate the lower mold 10, the upper mold 9 is also vibrated through the lower mold 10, so that the slurry S is placed between the lower mold 10 and the mold surface of the upper mold 9. Air bubbles are prevented from being generated, and moisture and air in the slurry S are uniformly discharged so that pores do not exist in the inside and silica airgel particles are mixed closely.

Next, the manufacturing method in which the primary molded product T is formed will be described with reference to FIGS. First, in FIG. 12, with the upper mold 9 and the lower mold 10 opened, the inorganic fiber cloth 2 illustrated in FIGS. 3 to 6 is disposed on the cylindrical wall 9A and the top wall 9B of the upper mold 9. After inserting the inorganic fiber cloth 3 into the cylindrical body 10A of the lower mold 10 so that the flange 3A is disposed on the base 10B of the lower mold 10, the lower mold 10 is moved in the direction of arrow P1 (FIG. 12). Then, the upper die 9 and the lower die 10 are closed as shown in FIG. In this case, an arrow Q1 in FIG. 12 indicates a moving direction in which the lower mold 10 moves from a position where it does not face the upper mold 9 to a position where it faces (moves leftward in FIG. 12).

Next, in FIG. 13, the upper mold 9 and the lower mold 10 are closed as described above, and the inorganic fiber cloths 2 and 3 are arranged in the space of the dehydration mold 11 sealed with the seal member 14. In this state, a predetermined amount of the hydrated and viscous slurry S is poured into the dehydration mold part 11 of the molding apparatus 6 and filled therein. The amount of the slurry S to be poured has been previously tested and confirmed to be a calcium silicate molded body having a large number of fine pores having a porosity of 50% or more. The volume of water and air discharged in the slurry S so that the silica airgel particles are closely mixed with the raw material composed of the calcium raw material and the silica airgel raw material or the raw material obtained by adding the inorganic fiber filler raw material to this raw material. The amount that fills the space of the dehydrating mold part 11 may be controlled in consideration of the above. In addition, the slurry S may be injected by connecting (not shown) with the slurry forming apparatus shown in FIG. 8 and mixing while kneading or by pumping. During the injection of the slurry S, the vibration mechanism member 13 is driven to vibrate the lower mold 10 and the upper mold 9 and the water absorption pump P is driven to cause the water absorption member 12 to move the moisture in the slurry S in the dehydration mold portion 11. A raw material composed of a powdered silicic acid raw material, a powdered calcium raw material and a silica airgel raw material by sucking air or a raw material obtained by adding an inorganic fiber filler raw material to this raw material is semi-cured. In this way, the primary molded product T that becomes the tubular heat insulating material 1 is formed in the dehydration mold part 11 of the molding apparatus 6 (see FIG. 14).

(Curing process)
15 and 16 show a curing process 103 in which a tubular heat insulating material 1 is formed by subjecting the primary molded article T formed as described above to an auto-prep (steam curing) treatment for a predetermined time, and drying and solidifying. The work in is shown.

In FIG. 15, by moving the lower mold 10 in the direction of the arrow P2 so that the upper mold 9 and the lower mold 10 are opened, the primary molded product T has a cylindrical shape corresponding to the tubular heat insulating material 1, The hollow portion is in the cylindrical body 10A of the lower mold 10, and the opened end surface is separated from the upper mold 9 so as to be placed on the lower mold 10 in the state of being in the base 10B of the lower mold 10. Next, by moving the lower mold 10 in the direction of the arrow Q2, the lower mold 10 moves from a position facing the upper mold 9 to a position not facing.

In FIG. 16, at the position where the lower mold 10 is moved in the direction of arrow Q2, the primary molded product T is taken out from the lower mold 10 in the direction of arrow P1, and this primary molded product T is sent to the curing device (not shown). Thus, since the primary molded product T is taken out, it is preferable to add an inorganic fiber filler to increase the strength and to make it semi-cured. In this curing device, the primary molded product T is subjected to autoclaving (steaming heat treatment) for 3 to 10 hours at a saturated water vapor pressure of 150 to 200 ° C. In this case, the silica airgel particles have a number of fine pores whose porosity is 50% or more in the calcium silicate molded body composed of silicic acid and calcium added with silicic acid and calcium or inorganic fiber filler. After a crepe (steaming) process, when not shown, it is sent to a drying furnace and dried to solidify. A cylindrical molding board in which many fine pores inside the calcium silicate compact are composed of silica airgel particles is formed. As a result, the silica airgel particles are densely mixed to have a large amount of silica airgel particles, and the cylindrical heat insulating material 1 that insulates the high-temperature heat device main body that effectively uses the heat insulating property of the silica airgel is obtained.

Since the present invention is a heat insulating material that is a cylindrical molded board made of a calcium silicate molded body composed of a large amount of silica airgel particles, it can be used in various applications as a heat insulating material that insulates a high-temperature heat device body, for example, It can be used as a heat insulating material for insulating a reformer of a polymer electrolyte fuel cell or a main body of a solid oxide fuel cell (or a solid electrolyte fuel cell). In particular, it is also effective for facilities where the installation area of thermal equipment cannot be increased.

DESCRIPTION OF SYMBOLS 1 Cylindrical heat insulating material 2 Inorganic fiber cloth 3 Inorganic fiber cloth 4 Slurry housing | casing 5 Stirring jig | tool A Thermal apparatus main body S Slurry T Primary molding

Claims (7)

In a heat insulating material made of a calcium silicate molded body having a large number of fine pores having a porosity of 50% or more, which is inserted into a heat device main body to insulate the heat device main body, the pores are made of silica. A cylindrical heat insulating material characterized by comprising airgel particles. The cylindrical heat insulating material according to claim 1, wherein an average particle diameter of the silica airgel particles is 1.5 mm. The cylindrical heat insulating material according to claim 1 or 2, wherein the calcium silicate compact is formed by adding an inorganic fiber filler to a powdered silicate raw material and a powdered calcium raw material. The cylindrical heat insulating material according to any one of claims 1 to 3, wherein the cylindrical heat insulating material is coated with an inorganic fiber cloth. In a method for manufacturing a heat insulating material made of a calcium silicate molded body having a large number of fine pores which are inserted into a thermal equipment body and insulate the thermal equipment body and have a porosity of 50% or more, Silica airgel by mixing a silica airgel raw material, a powdered silicic acid raw material, a powdered calcium raw material, and water in which a hydrophilic coating is formed on the surface of hydrophobic silica airgel particles that have been treated to prevent intrusion into the interior The slurry obtained by closely blending the particles with the powdered silicate raw material and the powdered calcium raw material is dehydrated into a cylindrical shape to form a primary molded product, and then the primary molded product is steam-cured and dried to solidify the calcium silicate A method for producing a cylindrical heat insulating material, characterized in that the pores of the calcium silicate molded body are composed of silica airgel particles by forming the molded body. Slurry obtained by adding an inorganic fiber filler to the powdered silicic acid raw material and powdered calcium raw material and stirring and mixing the silica airgel raw material and water is formed into a cylindrical shape by dehydrating the slurry. The method for producing a cylindrical heat insulating material according to claim 5. The method for producing a cylindrical heat insulating material according to claim 5 or 6, wherein the slurry is dewatered and formed into a primary molded product in a state where the inorganic fiber cloth is disposed.

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