Heat insulation material for combustion chamber, water heater and boiler

Abstract

To provide a heat insulation material for combustion chamber that can be stably mounted at the time of construction.SOLUTION: A heat insulation material for combustion chamber includes: a first heat insulation material layer; and a second heat insulation material layer laminated on one main surface of the first heat insulation material layer. The first heat insulation material layer and the second heat insulation material layer are an aggregate of inorganic fibers. The bulk density of the second heat insulation material layer is lower than the bulk density of the first heat insulation material layer. The second heat insulation material layer is formed by a papermaking method, the bulk density is 0.15-0.23 g / cm3, and the thickness is 3-7 mm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a combustion chamber insulation material, a water heater, and a boiler. [Background technology]

[0002] 2. Description of the Related Art Boilers and water heaters are used as devices that supply steam or hot water using fuels such as petroleum.

[0003] Boilers and water heaters generate steam or hot water from water by burning fuel in a combustion chamber and transferring the heat of combustion to water through water pipes placed inside the combustion chamber.

[0004] Because the combustion chamber becomes very hot, it is usually protected by refractories and heat insulating materials in order to protect surrounding equipment from heat damage and to reduce energy loss (see, for example, Patent Documents 1 and 2).

[0005] In particular, in combustion chambers where the temperature rises due to combustion gas, refractories and heat insulating materials are generally made by pouring a fluid containing heat-resistant material onto the surface of the object to be installed and solidifying it. Such materials are also called castable materials. Although castable materials can conform to surfaces of any shape and provide heat insulation, they have the problem of being heavy and difficult to work with during construction. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 4946594 [Patent Document 2] Patent No. 4640705 Summary of the Invention [Problem to be solved by the invention]

[0007] Instead of castable materials, the use of insulating materials containing inorganic fibers has been considered as an alternative. These insulating materials have insulating properties, durability, can be stably and easily installed and maintained, and can be supplied at low cost. However, the insulating material needs to be strong in order to withstand the combustion wind inside the combustion chamber and to be fixed to the ceiling of the metal wall of the combustion chamber with bolts or the like.

[0008] On the other hand, the surface of a metal wall has unevenness due to the metal surface itself and unevenness due to welding marks at the joints of the metal wall. For this reason, it is difficult to attach a strong insulation material to the metal wall horizontally and stably as designed, and there is an issue of gaps occurring between the metal wall and the insulation material.

[0009] The present invention has been made to solve the above problems, and an object of the present invention is to provide a combustion chamber insulating material that can be stably attached during construction. [Means for solving the problem]

[0010] That is, the combustion chamber insulating material of the present invention has a first insulating material layer and a second insulating material layer laminated on one main surface of the first insulating material layer, the first insulating material layer and the second insulating material layer are aggregates of inorganic fibers, the bulk density of the second insulating material layer is lower than the bulk density of the first insulating material layer, and the second insulating material layer is formed by a papermaking method and has a bulk density of 0.15 to 0.23 g / cm. 3 and has a thickness of 3 to 7 mm. The combustion chamber insulation material of the present invention has a first insulation layer with strength and a second insulation layer with low bulk density, so that when it is attached to the inner wall surface of a combustion chamber, the second insulation layer compresses and deforms to follow the unevenness of the inner wall surface, filling in the gap with the inner wall surface, allowing it to be attached stably.

[0011] The first heat insulating layer is a plate-shaped molded body having a flat or curved surface formed by a papermaking method, and has a bulk density of 0.24 to 0.35 g / cm 3 and the thickness is preferably 8 to 50 mm. When the first insulation layer has the above-mentioned bulk density and thickness, the combustion chamber insulation material of the present invention has higher insulation properties and durability.

[0012] The second insulating layer is preferably laminated on a portion of the first insulating layer. When the combustion chamber insulating material of the present invention is installed inside a combustion chamber, a space is created between the first insulating layer and the inner wall surface in the area where the second insulating layer is not laminated. This space improves the thermal insulation.

[0013] The second insulating layer is preferably laminated on a peripheral edge portion of the first insulating layer. When the second insulating material layer has the above-mentioned shape, the mounting stability and the insulating properties are further improved.

[0014] It is preferable that the first insulation layer contains an inorganic binder and the second insulation layer contains an organic binder. When the first insulation layer contains an inorganic binder, the strength of the combustion chamber insulation material is stabilized, and when the second insulation layer contains an organic binder, the shape of the second insulation layer can be maintained.

[0015] It is preferable that the second insulation layer contains an inorganic binder, and the content of the inorganic binder in the second insulation layer is less than the content of the inorganic binder in the first insulation layer. The second insulation layer contains an inorganic binder and has a lower inorganic binder content than the first insulation layer, so that the second insulation layer maintains its shape even though it has a low bulk density, and is soft enough to fill in irregularities in the inner wall surface of the combustion chamber.

[0016] The second thermal insulation layer preferably contains 0.01 to 3% by weight of an inorganic binder relative to the inorganic fibers. When the second insulating layer contains the inorganic binder in the above range, the second insulating layer maintains its shape even if its bulk density is low, and is soft enough to fill in irregularities on the inner wall surface of the combustion chamber.

[0017] It is preferable that the first insulating layer has a compressive stress of 90 kPa or more at a compression ratio of 25%, and the second insulating layer has a compressive stress of 70 kPa or less at a compression ratio of 25%. When the compressive stress of the first insulation layer is within the above range, the combustion chamber insulation material of the present invention has higher thermal insulation properties and durability. Also, when the compressive stress of the second insulation layer is within the above range, the second insulation layer is more easily compressively deformed, and the combustion chamber insulation material of the present invention can be attached more stably.

[0018] The water heater of the present invention comprises a combustion chamber, a heat exchanger installed within the combustion chamber, and a combustion chamber insulation material of the present invention, and is characterized in that the second insulation layer of the combustion chamber insulation material is arranged facing toward the inner wall surface of the combustion chamber.

[0019] The water heater of the present invention is equipped with the combustion chamber insulation material of the present invention, which has a first insulation layer having strength and a second insulation layer having low bulk density and thin thickness, so that when the combustion chamber insulation material is attached to the inner wall surface of the combustion chamber, the second insulation layer compresses and deforms along the unevenness of the inner wall surface to fill in gaps, allowing the combustion chamber insulation material of the present invention to be attached stably.

[0020] The boiler of the present invention is characterized in that it comprises a combustion chamber and the combustion chamber insulation material of the present invention, and the second insulation layer of the combustion chamber insulation material is arranged facing toward the inner wall surface of the combustion chamber.

[0021] The boiler of the present invention is equipped with the combustion chamber insulation material of the present invention, which has a first insulation layer having strength and a second insulation layer having low bulk density and small thickness. Therefore, when the combustion chamber insulation material is attached to the inner wall surface of the combustion chamber, the second insulation layer compresses and deforms along the unevenness of the inner wall surface to fill in gaps, allowing the combustion chamber insulation material of the present invention to be attached stably. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a perspective view that illustrates an example of a combustion chamber insulating material of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, showing a schematic internal structure of the combustion chamber insulating material. [Diagram 3] FIG. 3 is a perspective view that shows a typical modification of the combustion chamber insulating material of the present invention. [Figure 4] FIG. 4 is a cross-sectional view taken along line BB in FIG. 3, showing a schematic internal structure of the combustion chamber insulating material. [Diagram 5] FIG. 5 is a cross-sectional view that illustrates an example of a water heater of the present invention. [Figure 6] FIG. 6 is a cross-sectional view that illustrates an example of a boiler of the present invention. [Figure 7] FIG. 7 is a cross-sectional view that typically shows a usage mode in which the combustion chamber insulating material in FIG. 1 is attached to a metal wall. [Figure 8] FIG. 8 is a cross-sectional view that typically shows a usage mode in which the combustion chamber insulating material in FIG. 3 is attached to a metal wall. [Figure 9] FIG. 9 is a partially enlarged view of FIGS.

[0023] Detailed Description of the Invention The combustion chamber insulating material, water heater, and boiler of the present invention will be specifically described below. However, the present invention is not limited to the following configurations, and can be appropriately modified and applied within the scope of the present invention. Note that the present invention also includes a combination of two or more of the individual preferred configurations of the present invention described below.

[0024] [Insulation material for combustion chamber] First, the combustion chamber insulating material of the present invention will be described. The combustion chamber insulating material of the present invention has a first insulating material layer and a second insulating material layer laminated on one main surface of the first insulating material layer, the first insulating material layer and the second insulating material layer being aggregates of inorganic fibers, the bulk density of the second insulating material layer being lower than the bulk density of the first insulating material layer, and the second insulating material layer being formed by a papermaking method and having a bulk density of 0.15 to 0.23 g / cm. 3 and has a thickness of 3 to 7 mm.

[0025] Fig. 1 is a perspective view showing an example of a combustion chamber insulating material of the present invention, and Fig. 2 is a cross-sectional view taken along line AA showing an internal structure of the combustion chamber insulating material shown in Fig. 1. The combustion chamber insulating material 1 shown in FIGS. 1 and 2 has a first insulating material layer 10 and a second insulating material layer 20 laminated on one main surface 10a of the first insulating material layer 10.

[0026] As shown in FIG. 1, the first heat insulating layer 10 is a plate-shaped molded body having one main surface 10a and the other main surface 10b that are opposed to each other and have a relatively large area, and a side surface 10c that connects the one main surface 10a and the other main surface 10b. The second heat insulating layer 20 is a plate-shaped molded body having one main surface 20a and the other main surface 20b that are opposed to each other and have a relatively large area, and a side surface 20c that connects the one main surface 20a and the other main surface 20b. In this specification, the plate-shaped shape means a shape in which the dimension in the width direction x (hereinafter referred to as width) and the dimension in the length direction y (hereinafter referred to as length) are considerably larger than the dimension in the thickness direction z (hereinafter referred to as thickness or height), for example, a shape in which the width and length are 3 times or more, preferably 5 times or more, of the thickness. At least one of the two opposing main surfaces may be curved.

[0027] As shown in Fig. 1, the shape (also called the outline) of one main surface 10a and the other main surface 10b of the first insulating material layer as viewed from the thickness direction z, and the shape of one main surface 20a and the other main surface 20b of the second insulating material layer as viewed from the thickness direction z are circular. Therefore, the shape of the combustion chamber insulating material 1 is a disk shape having a predetermined thickness. The shape of the combustion chamber insulating material 1 does not have to be a disk shape. The shape of one main surface 10a and the other main surface 10b of the first insulation layer when viewed from the thickness direction z, and the shape of one main surface 20a and the other main surface 20b of the second insulation layer when viewed from the thickness direction z may be the same or different, but it is preferable that the shapes of one main surface 10a and the other main surface 10b of the first insulation layer are the same, the shapes of one main surface 20a and the other main surface 20b of the second insulation layer are the same, and the shape of the first insulation layer and the shape of the second insulation layer are the same. For example, in the modified example described below, the shape of the second insulation layer is annular, but even though a hole is formed on the inside, the outer contour is the same as that of the first insulation layer, in which case the shape of the first insulation layer and the shape of the second insulation layer are the same.

[0028] As shown in FIG. 1, the area (planar area) of the combustion chamber insulating material 1 as viewed in the thickness direction z is 350 to 15,000 cm 2 It is preferable that:

[0029] The first and second insulating layers are aggregates of inorganic fibers. The inorganic fibers preferably include at least one selected from the group consisting of biosoluble fibers, alumina fibers, rock wool, and glass fibers. As the biosoluble fiber, for example, alkaline earth silicate fiber (AES fiber) can be used. Also, shot components of non-fibrous particles may be contained. When the inorganic fibers contain the above-mentioned material, a plate-shaped molded product having excellent heat resistance can be obtained.

[0030] The average fiber diameter of the inorganic fibers is not particularly limited, but is preferably 2.0 to 15.0 μm when the plate-shaped molded product is a paper product. When the average fiber diameter of the inorganic fibers is within the above range, a dense plate-shaped molded product with little localized distribution of the inorganic fibers can be obtained.

[0031] The average fiber length of the inorganic fibers is not particularly limited, but is preferably 0.05 to 3.0 mm when the plate-shaped molded product is a paper product. When the average fiber length of the inorganic fibers is within the above range, a plate-shaped molded product can be obtained in which the inorganic fibers are laminated with little local bias, and the heat insulation properties are stable.

[0032] Combustion chamber insulation consists of a first insulation layer, which is an aggregate of inorganic fibers, and a second insulation layer, which is also an aggregate of inorganic fibers, so it has a smaller weight per volume and is easier to work with than castable materials. Combustion chamber insulation has the property of having less localized bias in the inorganic fibers and being less prone to deformation, making it suitable as insulation to be placed inside a combustion chamber.

[0033] The first heat insulating layer may be formed by a papermaking method or a needle method, but is preferably a plate-shaped molded body including a flat or curved surface formed by a papermaking method. The papermaking method is a method in which a slurry containing inorganic fibers is poured into a molding die, and a molded body is obtained by papermaking molding in which suction dehydration is performed, and then drying. The needle method is a method in which a molded body is obtained by subjecting an inorganic fiber aggregate to a needling treatment. When the first heat insulating layer is a plate-shaped molded body formed by a papermaking method, the bulk density can be increased to impart strength and heat insulation.

[0034] The first insulation layer has a bulk density of 0.20 to 0.35 g / cm 3 and preferably 0.24 to 0.35 g / cm 3 When the bulk density of the first heat insulating material layer is within the above range, the heat insulating material can exhibit sufficient strength (bending strength) and heat insulating properties. More preferably, the bulk density is 0.27 to 0.35 g / cm. 3 Bulk density can be calculated by dividing the mass by the apparent volume (see JIS A0202_2213).

[0035] The first insulating layer preferably has a thickness of 8 to 50 mm. When the thickness of the first insulating layer is within the above range, the insulating material can exhibit sufficient heat insulating properties. The thickness of the first insulating layer is more preferably 14 to 40 mm.

[0036] The first insulating layer preferably contains an inorganic binder. When the first insulating layer contains an inorganic binder, the strength of the combustion chamber insulating material is stabilized. Examples of inorganic binders include silica sol, alumina sol, titania sol, zirconia sol, and fumed silica. The first insulating layer preferably contains 5 to 15% by weight of the inorganic binder relative to the inorganic fibers.

[0037] The first heat insulating layer may contain an organic binder, such as polyvinyl alcohol, starch, acrylic resin, polyacrylamide, or the like.

[0038] The second insulation layer is formed by a papermaking method, and the bulk density of the second insulation layer is lower than the bulk density of the first insulation layer. The combustion chamber insulation material has a first insulation layer with strength and a second insulation layer with low bulk density, so that when attached to the inner wall surface of the combustion chamber, the second insulation layer compresses and deforms along the unevenness of the inner wall surface to fill the gap with the inner wall surface, allowing for stable attachment. Regarding the unevenness of the inner wall surface, for example, there is a step of about 2 mm at the joints between the inner wall surfaces and at the welded parts between the inner wall surface and bolts, water pipes, metal fittings, etc.

[0039] The second insulation layer has a bulk density of 0.15 to 0.23 g / cm 3 Preferably, the bulk density is 0.17 to 0.22 g / cm 3 It is.

[0040] The second insulating material layer has a thickness of 3 to 7 mm. If the thickness is within this range, the strength of the combustion chamber insulating material is maintained and the material can be stably attached.

[0041] The second heat insulating layer preferably contains an organic binder. Examples of the organic binder include the organic binders that can be used in the first heat insulating layer, as well as amorphous thermoplastic resins having a glass transition temperature (Tg) of 10° C. or less. When the second heat insulating layer contains an amorphous thermoplastic resin having a Tg of 10° C. or less as an organic binder, the second heat insulating layer has a softness that fills in irregularities in the inner wall surface of the combustion chamber while maintaining its shape in the room temperature range where the combustion chamber heat insulating material is attached to the inner wall surface of the combustion chamber.

[0042] The second insulating layer preferably contains an inorganic binder, such as the same inorganic binders that can be used in the first insulating layer.

[0043] The inorganic binder content of the second insulating layer is preferably less than that of the first insulating layer. Since the second insulating layer contains an inorganic binder and has a lower inorganic binder content than the first insulating layer, the second insulating layer maintains its shape even with a low bulk density and has softness to fill in irregularities on the inner wall surface of the combustion chamber. The second insulating layer preferably contains 0.01 to 3% by weight of the inorganic binder relative to the inorganic fibers. The second insulating layer also has improved wind corrosion resistance by containing an inorganic binder.

[0044] The first and second insulating layers may further contain inorganic particles, a polymer flocculant, an inorganic flocculant, and the like. Examples of inorganic particles include silica particles, alumina particles, titania particles, zirconia particles, and natural mineral particles.

[0045] The first insulating layer preferably has a compressive stress of 90 kPa or more at a compression ratio of 25%, and the second insulating layer preferably has a compressive stress of 70 kPa or less at a compression ratio of 25%. When the compressive stress of the first insulation layer is within the above range, the combustion chamber insulation has higher insulation properties and durability. When the compressive stress of the second insulation layer is within the above range, the second insulation layer is more easily compressively deformed, and the combustion chamber insulation can be attached more stably. The compressive stress of the first insulation layer at a compression ratio of 25% is more preferably 100 kPa or more. The compressive stress of the second insulation layer at a compression ratio of 25% is more preferably 60 kPa or less.

[0046] The upper limit of the compressive stress of the first insulating layer at a compression ratio of 25% is not particularly limited, but is, for example, 700 kPa or less. The lower limit of the compressive stress of the second insulating layer at a compression ratio of 25% is not particularly limited, but is, for example, 5 kPa or more. The compressive stress of the first insulation layer at a compression rate of 25% and the compressive stress of the second insulation layer at a compression rate of 25% were calculated using the following formula, where the load was the compressive load when the sample was compressed 25% in the thickness direction at a compression speed of 1 mm / min using a universal testing machine. Compressive stress at 25% compression (kPa) = Compressive load (N) / Sample area (cm 2 )×0.1

[0047] Next, a combustion chamber insulating material 1A, which is a modified example of the combustion chamber insulating material 1, will be described below with reference to Figures 3 and 4. Here, only the differences from the combustion chamber insulating material 1 will be described, and a description of the common points will be omitted.

[0048] Fig. 3 is a perspective view showing a modified example of the combustion chamber insulating material of the present invention, and Fig. 4 is a cross-sectional view taken along line BB showing the internal structure of the combustion chamber insulating material in Fig. 3. In the combustion chamber insulating material 1A, the one main surface 20a and the other main surface 20b of the second insulating material layer when viewed from the thickness direction z are annular, as shown in Fig. 3. In other words, the shape of the second insulating material layer 20 when viewed from the thickness direction z is annular.

[0049] In the combustion chamber insulating material 1A, as shown in Figures 3 and 4, one main surface 10a of the first insulating material layer 10 is exposed in the inner portion of the ring of the second insulating material layer 20. As described below, when the combustion chamber insulating material 1A is attached to the inner wall surface of the combustion chamber, the inner portion of the ring of the second insulating material layer 20 becomes a space surrounded by the inner wall surface of the combustion chamber, the side surface 20c of the second insulating material layer, and one main surface 10a of the first insulating material layer. By providing such a space, the combustion chamber insulating material 1A has higher insulating properties than the combustion chamber insulating material 1. The shape of the second insulation layer 20 as viewed from the thickness direction z is not limited to a circular ring shape. From the viewpoint of the thermal insulation properties of the combustion chamber insulation material 1A, the second insulation layer 20 is preferably laminated on a part of the first insulation layer 10, and from the viewpoint of the thermal insulation properties and the ability to be stably attached during construction, it is more preferable that the second insulation layer 20 is laminated on the peripheral portion of the first insulation layer 10.

[0050] The method for producing the combustion chamber insulating material of the present invention is not particularly limited, but it can be produced, for example, by the following procedure. Step (1) A slurry for the first insulation layer containing water, inorganic fibers, an inorganic binder, an organic binder, and a flocculant is prepared, and a base sheet for the first insulation layer is obtained by a papermaking method. The inorganic binder, the organic binder, and the flocculant are optional components. Step (2) After papermaking, the original sheet of the first insulation layer containing moisture is removed from the mold and placed on a stainless steel metal plate. A stainless steel wire mesh of the same length and width as the stainless steel metal plate is placed on top of the original sheet and dried to obtain the first insulation layer. Step (3) Next, a slurry for the second insulation layer containing water, inorganic fibers, an inorganic binder, an organic binder and a flocculant is prepared, and a base sheet for the second insulation layer is obtained by a papermaking method. The inorganic binder, the organic binder and the flocculant are optional components. Step (4) After papermaking, the original sheet of the second insulation layer containing moisture is removed from the mold and placed on a stainless steel metal plate. A stainless steel wire mesh of the same length and width as the stainless steel metal plate is placed on top of the original sheet and dried to obtain the second insulation layer. In step (5), a second insulating layer is superimposed on the first insulating layer to obtain the combustion chamber insulating material of the present invention.

[0051] The heat insulating material for a combustion chamber of the present invention can be used, for example, in an apparatus equipped with a combustion chamber, such as a water heater or a boiler.

[0052] [Water heater] The water heater of the present invention comprises a combustion chamber, a heat exchanger installed within the combustion chamber, and a combustion chamber insulation material of the present invention, and is characterized in that the second insulation layer of the combustion chamber insulation material is arranged facing toward the inner wall surface of the combustion chamber. The water heater of the present invention is equipped with the combustion chamber insulation material of the present invention, which has a first insulation layer having strength and a second insulation layer having low bulk density and thin thickness, so that when the combustion chamber insulation material is attached to the inner wall surface of the combustion chamber, the second insulation layer compresses and deforms along the unevenness of the inner wall surface to fill in gaps, allowing the combustion chamber insulation material of the present invention to be attached stably.

[0053] An example of a water heater according to the present invention will be described below. FIG. 5 is a cross-sectional view that illustrates an example of a water heater of the present invention. 5, water heater 500 has a combustion chamber 540 and a heat exchanger 170 disposed within combustion chamber 540. Combustion chamber 540 has a metal container 150 and two combustion chamber insulation materials 1 disposed on top surface 150a and bottom surface 150b of the metal container. Combustion chamber insulation material 1 is disposed such that one main surface 20a of the second insulation layer faces the inner wall surface of the combustion chamber. Water flows in heat exchanger 170, and the water in heat exchanger 170 is heated in combustion chamber 540 to become hot water (hot water), and the hot water (hot water) is supplied to the outside of water heater 500.

[0054] The temperature of the hot water supplied can be appropriately adjusted by adjusting the amount of fuel burned in the combustion chamber and the amount of water passing through the heat exchanger per unit time.

[0055] [boiler] The boiler of the present invention is characterized in that it comprises a combustion chamber and the combustion chamber insulation material of the present invention, and the second insulation layer of the combustion chamber insulation material is arranged facing toward the inner wall surface of the combustion chamber. The boiler of the present invention is equipped with the combustion chamber insulation material of the present invention, which has a first insulation layer having strength and a second insulation layer having low bulk density and small thickness. Therefore, when the combustion chamber insulation material is attached to the inner wall surface of the combustion chamber, the second insulation layer compresses and deforms along the unevenness of the inner wall surface to fill in gaps, allowing the combustion chamber insulation material of the present invention to be attached stably.

[0056] An example of a boiler according to the present invention will now be described. FIG. 6 is a cross-sectional view that illustrates an example of a boiler of the present invention. As shown in FIG. 6, the boiler 600 has a combustion chamber 550 and a water tube 180 disposed within the combustion chamber 550 . The combustion chamber 550 has a metal container 160 and two combustion chamber insulation materials 1 arranged on a top surface 160a and a bottom surface 160b of the metal container. The combustion chamber insulation material 1 is arranged such that one main surface 20a of the second insulation layer faces the inner wall surface of the combustion chamber (the top surface 160a and the bottom surface 160b of the metal container). Water is supplied into the water pipe 180 from the lower part of the combustion chamber 550 , and the water passing through the water pipe 180 is heated in the combustion chamber 550 to become steam, which is discharged from the upper part of the combustion chamber 550 . The discharged water vapor is used for power generation, heating, cleaning, cooking, drying, disinfection, sterilization, etc. after separating the liquid water or superheating as necessary.

[0057] The method of arranging the combustion chamber insulation material on the inner wall surface of the combustion chamber is not particularly limited, and for example, it can be fixed with fasteners such as bolts and nuts. One main surface of the second insulation layer of the combustion chamber insulation material may be arranged on the inner wall surface of the combustion chamber via an inorganic adhesive, but it is preferable to fix the combustion chamber insulation material with a fastener because it is easy to replace. The combustion chamber insulation material may have a hole formed therein through which the fastener for arrangement on the inner wall surface of the combustion chamber passes.

[0058] The present specification discloses the following:

[0059] The present disclosure (1) provides a heat insulating material having a first heat insulating layer and a second heat insulating layer laminated on one main surface of the first heat insulating layer, the first heat insulating layer and the second heat insulating layer being aggregates of inorganic fibers, the bulk density of the second heat insulating layer being lower than the bulk density of the first heat insulating layer, the second heat insulating layer being molded by a papermaking method and having a bulk density of 0.15 to 0.23 g / cm 3 and a thickness of 3 to 7 mm.

[0060] The present disclosure (2) relates to a method for manufacturing a heat insulating material having a bulk density of 0.24 to 0.35 g / cm3, wherein the first heat insulating material layer is a plate-shaped molded body having a flat or curved surface formed by a papermaking method. 3 and a thickness of 8 to 50 mm.

[0061] The present disclosure (3) is the combustion chamber insulating material according to the present disclosure (1) or (2), in which the second insulating material layer is laminated on a part of the first insulating material layer.

[0062] The present disclosure (4) is the combustion chamber insulating material according to any one of the present disclosures (1) to (3), in which the second insulating material layer is laminated on the peripheral edge of the first insulating material layer.

[0063] The present disclosure (5) is the combustion chamber insulating material according to any one of the present disclosures (1) to (4), in which the first insulating material layer contains an inorganic binder and the second insulating material layer contains an organic binder.

[0064] The present disclosure (6) is a combustion chamber insulation material described in the present disclosure (5), wherein the second insulation layer contains an inorganic binder, and the content of the inorganic binder in the second insulation layer is less than the content of the inorganic binder in the first insulation layer.

[0065] The present disclosure (7) is the combustion chamber insulating material according to the present disclosure (6), wherein the second insulating material layer contains 0.01 to 3.0% by weight of an inorganic binder relative to the inorganic fibers.

[0066] The present disclosure (8) is a combustion chamber insulation material described in any one of the present disclosures (1) to (7), in which the first insulation layer has a compressive stress of 90 kPa or more at a compression ratio of 25%, and the second insulation layer has a compressive stress of 70 kPa or less at a compression ratio of 25%.

[0067] The present disclosure (9) provides a combustion chamber, A heat exchanger installed in the combustion chamber; The combustion chamber insulating material according to any one of (1) to (8) of the present disclosure, The water heater is characterized in that the second insulation layer of the combustion chamber insulation is arranged facing the inner wall surface.

[0068] The present disclosure (10) provides a combustion chamber, The combustion chamber insulating material according to any one of (1) to (8) of the present disclosure, The boiler is characterized in that the second insulation layer of the combustion chamber insulation is arranged facing the inner wall surface.

[0069] (Example) EXAMPLES Hereinafter, examples that more specifically disclose the present invention will be described, however, the present invention is not limited to these examples.

[0070] Example 1 Water, AES fiber, inorganic binder (silica sol), polymer flocculant and inorganic flocculant (aluminum sulfate) were added to a commercially available pulper and dispersed to prepare a slurry. Six parts by weight of inorganic binder was mixed with 100 parts by weight of AES fiber. The prepared slurry was poured into a mold, dehydrated, and a base sheet was obtained by a papermaking method. The base sheet was dried at 150°C for 12 hours and the bulk density was 0.27 g / cm. 3 A first insulation layer having a thickness of 20 mm was obtained. The obtained first insulation layer was cut into a sheet of 50 mm x 50 mm to prepare a measurement sample, and a universal testing machine was used to measure the compression load at a compression ratio of 25% and calculate the compression stress. The compression stress of the first insulation layer at a compression ratio of 25% was 129 kPa.

[0071] Next, water, AES fiber, organic binder (acrylate resin with Tg of -9°C) and inorganic flocculant (aluminum sulfate) were added to a commercially available pulper and dispersed to prepare a slurry. 7 parts by weight of organic binder was mixed with 100 parts by weight of AES fiber. The prepared slurry was poured into a mold, dehydrated, and a base sheet was obtained by a papermaking method. The base sheet was dried at 150°C for 1 hour and the bulk density was 0.21 g / cm. 3 A second insulating layer having a thickness of 4 mm was obtained. The compressive load of the second insulating layer was measured at a compression ratio of 25% in the same manner as the first insulating layer, and the compressive stress was calculated. The compressive stress of the second insulating layer at a compression ratio of 25% was 12 kPa. A second insulating layer was laminated on the obtained first insulating layer to obtain the combustion chamber insulating material shown in FIG.

[0072] Example 2 The first heat insulating layer was prepared in the same manner as in Example 1. Water, AES fiber, organic binder (acrylate resin with Tg of -9°C), inorganic binder (silica sol) and inorganic flocculant (aluminum sulfate) were added to a commercially available pulper and dispersed to prepare a slurry. 2 parts by weight of inorganic binder and 7 parts by weight of organic binder were mixed with 100 parts by weight of AES fiber. The prepared slurry was poured into a mold, dehydrated and a base sheet was obtained by a papermaking method. The base sheet was dried at 150°C for 1 hour and the bulk density was 0.22 g / cm. 3 A second insulating layer having a thickness of 4 mm was obtained. The compressive load of the second insulating layer was measured at a compression ratio of 25% in the same manner as the first insulating layer, and the compressive stress was calculated. The compressive stress of the second insulating layer was 41 kPa. A second insulating layer was laminated on the obtained first insulating layer to obtain the combustion chamber insulating material shown in FIG.

[0073] Example 3 A combustion chamber insulating material was obtained in the same manner as in Example 1, except that the shape of the second insulating material layer was a hollow disk when viewed in the thickness direction, as shown in FIG.

[0074] Comparative Example 1 A combustion chamber insulating material of Comparative Example 1 was obtained in the same manner as in Example 1, except that only the first insulating material layer was used.

[0075] (evaluation) In the combustion chamber insulating materials of Examples 1 to 3 and Comparative Example 1, bolts were fixed to the metal wall by welding as shown in Figs. 7, 8 and 9. Fig. 7 is a cross-sectional view showing a typical usage state in which the combustion chamber insulating material in Fig. 1 is attached to a metal wall. Fig. 8 is a cross-sectional view showing a typical usage state in which the combustion chamber insulating material in Fig. 3 is attached to a metal wall. Fig. 9 is a partial enlarged view of Figs. 7 and 8. At the base of the bolt 40, a weld bead 50 was attached to a part of the surface of the metal wall with a leg length (S1) of 2 mm. A hole through which the bolt 40 passes was formed in the combustion chamber insulating materials 1 and 1A of Examples 1 to 3 and the combustion chamber insulating material of Comparative Example 1, and the bolt 40 was inserted through the combustion chamber insulating materials 1 and 1A of Examples 1 to 3 and the combustion chamber insulating material of Comparative Example 1 so that one main surface 20a of the second insulating material layer of the combustion chamber insulating materials 1 and 1A of Examples 1 to 3 and the combustion chamber insulating material of Comparative Example 1 was aligned along the surface 30a of the metal wall, and the bolt 40 was disposed to pass through the combustion chamber insulating materials, and fixed with a nut 60. At this time, the gap between the metal wall 30 and the combustion chamber insulation material was visually confirmed. In the combustion chamber insulation material of Comparative Example 1, gaps were observed between the first insulation layer (the combustion chamber insulation material itself) and the metal wall, but in the combustion chamber insulation materials of Examples 1 to 3, no gaps were observed between the second insulation layer and the metal wall. [Explanation of symbols]

[0076] 1. 1A Combustion chamber insulation material 10 First insulation layer 10a: one main surface of the first heat insulating layer 10b the other main surface of the first heat insulating material layer 10c Side of first insulation layer 20 Second insulation layer 20a: one main surface of the second heat insulating layer 20b the other main surface of the second heat insulating material layer 20c Side of second insulation layer 30 metal wall 30a Metal wall surface 40 Volts 50 Weld Bead 60 Nut 150, 160 metal container 150a, 160a Top surface of metal container 150b, 160b Bottom surface of metal container 170 Heat exchanger 180 Water pipe 500 Water Heater 540, 550 combustion chamber 600 Boiler

Claims

1. A first insulation layer and a second insulation layer laminated on one main surface of the first insulation layer, The first insulation layer and the second insulation layer are aggregates of inorganic fibers, The bulk density of the second insulation layer is lower than the bulk density of the first insulation layer; The second heat insulating layer is formed by a papermaking method and has a bulk density of 0.15 to 0.23 g / cm ３ and a thickness of 3 to 7 mm.

2. The first heat insulating layer is a plate-shaped molded body having a flat or curved surface formed by a papermaking method, and has a bulk density of 0.24 to 0.35 g / cm ３ The combustion chamber insulating material according to claim 1, wherein the thickness is 8 to 50 mm.

3. The combustion chamber insulation material according to claim 1 , wherein the second insulation layer is laminated on a portion of the first insulation layer.

4. The combustion chamber insulation material according to claim 1 , wherein the second insulation layer is laminated on a peripheral edge portion of the first insulation layer.

5. 2. The combustion chamber insulation material of claim 1, wherein the first insulation layer comprises an inorganic binder and the second insulation layer comprises an organic binder.

6. The combustion chamber insulation material according to claim 5 , wherein the second insulation layer contains an inorganic binder, and the content of the inorganic binder in the second insulation layer is less than the content of the inorganic binder in the first insulation layer.

7. The combustion chamber insulation material according to claim 6, wherein the second insulation layer contains 0.01 to 3.0% by weight of an inorganic binder relative to the inorganic fibers.

8. 2. A combustion chamber insulating material according to claim 1, wherein the first insulating layer has a compressive stress of 90 kPa or more at a compression ratio of 25%, and the second insulating layer has a compressive stress of 70 kPa or less at a compression ratio of 25%.

9. A combustion chamber; A heat exchanger installed in the combustion chamber; The combustion chamber insulating material according to any one of claims 1 to 8, A water heater characterized in that the second insulation layer of the combustion chamber insulation is arranged facing the inner wall surface of the combustion chamber.

10. A combustion chamber; The combustion chamber insulating material according to any one of claims 1 to 8, A boiler characterized in that the second insulation layer of the combustion chamber insulation is arranged facing the inner wall surface of the combustion chamber.

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