Fireproof wrapping structure

Abstract

To provide a fireproof wrapping structure capable of reducing its weight while ensuring fireproof performance.SOLUTION: A fireproof wrapping structure comprises: a first layer having one side facing an ignition side, and formed of a first heat insulating material having a first thermal conductivity; a second layer having one side adjacent to the other side of the first layer, and formed of a second heat insulating material having a second thermal conductivity higher than the first thermal conductivity; and a third layer having one side adjacent to the other side of the second layer, and formed of a heat-absorbing material. When a predetermined time has elapsed after ignition, the first layer is formed into a first layer thickness such that heat transferred from an ignition source is lowered to a first drop within a first predetermined temperature range and then transferred to the second layer, a second layer is formed into a second layer thickness such that the heat transferred within the first predetermined temperature range is lowered to a second drop within a second predetermined temperature range in which the heat-absorbing material exhibits a heat-absorbing effect and is transferred to the third layer, and the third layer maintains the heat within the second predetermined temperature range transferred from the second layer within the second predetermined temperature range based on the heat-absorbing reaction of the heat-absorbing material.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fire-resistant wrapping structure that improves heat resistance performance. [Background technology]

[0002] In the event of an external fire at a facility such as a power plant, in order to prevent damage to cable equipment such as cables in cable trays or conduits that house cables, a method of covering the cable trays and cables with a wrapping material having fire resistance is known (see, for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-048405 A [Patent Document 2] JP 2015-171176 A [Patent Document 3] JP 2020-076504 A Summary of the Invention [Problem to be solved by the invention]

[0004] The fire-resistant wrapping material is required to have fire resistance performance to maintain the protected object for a predetermined time until fire-fighting work is performed in the event of a fire occurring outside the cable facility. The fire-resistant wrapping material covers the cable facility over a long distance, and is desirably formed as light as possible to ensure earthquake resistance. According to the conventional techniques described in Patent Documents 1 to 3, a heat insulating layer is used in the wrapping material to ensure fire resistance. If fire resistance performance is to be ensured to maintain the protected object for a predetermined time after a fire occurs based on the conventional techniques, the thickness of the heat insulating layer increases, and there is a risk of the weight of the facility increasing.

[0005] An object of the present invention is to provide a fire-resistant wrapping structure that can be made lighter while ensuring fire resistance. [Means for solving the problem]

[0006] One aspect of the present invention is a fire extinguisher that includes a first layer having one side disposed on the ignition side and made of a first heat insulating material having a first thermal conductivity, a second layer having one side disposed adjacent to the other side of the first layer and made of a second heat insulating material having a second thermal conductivity higher than the first thermal conductivity, and a third layer having one side disposed adjacent to the other side of the second layer and made of a heat absorbing material, Between 30 minutes and 3 hours The first layer is formed to a first thickness for firstly lowering the heat transferred from the ignition source to a first predetermined temperature range and transferring it to the second layer, and the second layer is formed to a second thickness for secondly lowering the heat transferred in the first predetermined temperature range to a second predetermined temperature range in which the heat absorbing material exerts a heat absorbing effect and transferring it to the third layer, and the third layer maintains the heat in the second predetermined temperature range transferred from the second layer at the second predetermined temperature range based on the endothermic reaction of the heat absorbing material, and the temperature of the ignition source progresses along a standard heating temperature curve specified in ISO834, and the first predetermined temperature range is Over 420℃, 640° C. or less, and the second predetermined temperature range is Over 80℃, Below 280℃ wherein the thermal conductivity of the first layer in the first predetermined temperature range is 0.02 W / m K or more and 0.04 W / m K or less, and the thermal conductivity of the second layer in the second predetermined temperature range is 0.03 W / m K or more and 0.05 W / m K or less. It has a fire-resistant wrapping structure.

[0007] According to the present invention, since the first layer, which has a lower thermal conductivity than the second layer, is provided on the heating side of the second layer, the second layer thickness of the second layer can be made thinner than when the heating side is formed only with the second layer to have the same level of fire resistance, and the weight can be reduced. Also, according to the present invention, the first layer thickness of the first layer and the second layer thickness of the second layer are formed so that the third layer has a heat absorbing effect, so that the fire resistance can be guaranteed.

[0008] In one aspect of the present invention, a first layer is formed of a first insulating material having a first thermal conductivity and one side of the first layer is adjacent to the other side of the first layer, The first layer Same as Made of one material and a third layer formed of a heat absorbing material and provided with one side adjacent to the other side of the second layer, wherein, in a state where a predetermined time has elapsed since ignition, the first layer and the second layer are formed to a first layer thickness and a second layer thickness, respectively, for lowering the heat transferred from the ignition source to a second predetermined temperature range in which the heat absorbing material exerts a heat absorbing effect and transferring the heat to the third layer, the third layer maintains the heat in the second predetermined temperature range transferred from the second layer within the second predetermined temperature range based on the endothermic reaction of the heat absorbing material, the temperature of the ignition source progresses along the standard heating temperature curve specified in ISO834, the predetermined time is 3 hours, and the second predetermined temperature range is 300°C or less.

[0009] According to the present invention, by forming the second layer from the same material as the first layer, the second layer thickness of the second layer can be made thinner than when it is formed from the second insulating material, and the weight can be reduced.

[0010] The present invention may also include a fourth layer, one side of which is adjacent to the other side of the third layer, made of the same material as the second layer, and having an object to be protected placed on its other side, and the fourth layer may be formed to a fourth layer thickness that reduces the heat transferred in the second predetermined temperature range to a third predetermined temperature range in which the object to be protected is maintained, and transfers the heat to the object to be protected.

[0011] According to the present invention, when the temperature of the third layer after heat absorption is higher than the design temperature at which the protected object can be maintained, the fourth layer thickness of the fourth layer can be adjusted to lower the temperature to a third predetermined temperature range at which the protected object can be maintained.

[0012] In addition, the first layer thickness and the second layer thickness of the present invention are adjusted so that the second layer transmits heat in the second predetermined temperature range to the third layer during a predetermined fire resistance time after ignition, and the third layer uses up the heat absorption effect. The fire resistance performance time is 3 hours. Good too.

[0013] According to the present invention, the third layer uses up its heat absorbing effect during the fire resistance period, so that the excess heat absorbing material in the third layer can be reduced, resulting in a reduction in weight.

[0014] The heat absorbing material of the present invention may be formed from a powder material that separates water based on a chemical reaction when heated and exhibits an endothermic reaction.

[0015] According to the present invention, since the heat absorbing material does not normally contain moisture, performance degradation due to drying does not occur, and performance can be continuously maintained over time. Effect of the Invention

[0016] According to the present invention, it is possible to reduce the weight while ensuring fire resistance. [Brief description of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view showing a configuration of a fire-resistant wrapping structure according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing the configuration of a heat absorbing layer. [Diagram 3] FIG. 1 is a diagram showing the thermal conductivity of each material. [Figure 4] FIG. 4 is an enlarged view showing the thermal conductivity of each material in a low-temperature portion. [Diagram 5] FIG. 2 is a diagram showing the configuration of a heat absorbing material. [Figure 6] FIG. 2 is a cross-sectional view showing the configuration of a fire-resistant wrapping structure that is used for comparison in a performance test. [Figure 7] FIG. 11 is a diagram comparing the heat transfer performance of refractory wrapping structures. [Figure 8] FIG. 13 is a diagram showing the results of a performance test of the heat absorbing material. [Figure 9] FIG. 2 is a cross-sectional view showing the configuration of a fire-resistant wrapping structure that is used for comparison in a performance test. [Figure 10] FIG. 13 is a diagram showing the results of a performance test. [Figure 11] FIG. 13 is a diagram showing the heat transfer performance of a comparative example of a fire-resistant wrapping structure. [Figure 12] FIG. 2 is a cross-sectional view showing the configuration of a fire-resistant wrapping structure that is used for comparison in a performance test. [Figure 13] FIG. 13 is a diagram showing the heat transfer performance of a comparative example of a fire-resistant wrapping structure. [Figure 14] FIG. 13 is a diagram showing the results of a performance test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, a fire-resistant wrapping structure according to an embodiment of the present invention will be described with reference to the drawings.

[0019] Facilities such as nuclear power plants are equipped with cable equipment, such as power cables and communication cables, and cable trays that house and support the cables. In the unlikely event of an external fire breaking out, the cable equipment is required to have fire-resistant measures in place to protect the cable equipment, which is the object of protection inside, from fire for a specified period of time (e.g., about three hours) until fire-fighting work can be carried out. It is also desirable for the fire-resistant measures to be lightweight in order to ensure the earthquake resistance of the cable equipment. The fire-resistant wrapping structure of the embodiment has a lightweight configuration while ensuring the fire-resistant performance that protects the object of protection.

[0020] As shown in Figures 1 and 2, the fire-resistant wrapping structure 1 has a four-layer structure formed of different types of sheet materials. The fire-resistant wrapping structure 1 is configured to reduce the temperature caused by heat generated on the heated surface on the ignition side to a temperature that can protect the object to be protected K on the non-heated surface side. The object to be protected K is, for example, a cable installation. The fire-resistant wrapping structure 1 includes a first layer 2 that is disposed with one surface 2A, which is the heated surface side, exposed to the outside.

[0021] The first layer 2 is formed, for example, of a sheet-like first insulating material. The first insulating material is, for example, WDS (registered trademark). The first insulating material is, for example, a material with a low first thermal conductivity (see Figs. 3 and 4). The thermal conductivity of WDS is, for example, about 0.04 W / m·K at 800°C. WDS is a high insulating material with low thermal conductivity even in high temperature regions. The first insulating material is, for example, formed of fine fumed silica and a substance that does not transmit infrared rays. The first insulating material has, for example, a micropore structure in which countless fine holes with a diameter of 100 nm or less are formed, which regulates the movement of air molecules. The first insulating material has low elasticity and poor workability compared to the second insulating material (AES) of the second layer 3 described later. The one surface 2A side of the first layer 2 is arranged, for example, so as to face an ignition source.

[0022] The second layer 3 is provided adjacent to the first layer 2 on the other surface 2B side. The first layer 2 is formed to a first layer thickness that, for example, after a predetermined time has elapsed since ignition, causes the temperature generated by the heat transferred from the ignition source on the one surface 2A to drop to a first predetermined temperature range and transfers the temperature to the second layer 3 on the other surface 2B side. The first layer thickness is, for example, 10 mm.

[0023] The second layer 3 has one surface 3A facing the other surface 2B of the first layer 2. The second layer 3 is formed of a sheet-like second insulating material. The second insulating material is, for example, AES (alkaline earth silicate) wool. The second insulating material is, for example, a mineral fiber insulating material having a chemical composition mainly composed of high-purity silica, calcia, and magnesia. The second insulating material may also be formed of bioabsorbable fibers that can be decomposed or absorbed in the body. The second thermal conductivity of the second insulating material is higher than the first thermal conductivity of the first insulating material of the first layer 2. The second insulating material has a faster heat transfer rate than the first insulating material (see Figures 3 and 4). The thermal conductivity of AES is higher than that of WDS, especially in the high temperature range (800°C) than in the low temperature range (400°C).

[0024] A third layer 4 is provided on the other surface 3B side of the second layer 3. The second layer 3 is formed to a second layer thickness that reduces the heat transferred by the first layer 2 in the first predetermined temperature range to a second predetermined temperature range in which the heat absorbing material exerts its heat absorbing effect, and transfers the heat to the third layer 4. The second layer thickness is, for example, 13 mm.

[0025] The third layer 4 has one surface 4A facing the other surface 3B of the second layer 3. The third layer 4 absorbs heat in a second predetermined temperature range transferred from the second layer 3 based on a chemical reaction, and exerts a heat absorption effect. The third layer 4 suppresses a temperature rise and transfers the heat while maintaining the second predetermined temperature range. The third layer 4 includes, for example, two layers of heat absorbing material 4T (see FIG. 2). The heat absorbing material 4T is formed by accommodating a heat absorbing material 4Q in a storage space formed in a bag shape by a pair of heat insulating sheets 4S. The heat insulating sheets 4S are formed, for example, by a woven fabric made of fire-resistant fibers such as aluminum glass cloth. The pair of heat insulating sheets 4S are provided with perforations 4M for each predetermined rectangular unit, and the heat absorbing material 4T is arranged in a matrix of a plurality of rectangular small bags 4R (see FIG. 5).

[0026] The heat absorbing material 4Q is formed of a powder material that does not contain moisture in order to prevent the heat absorbing effect from decreasing due to drying over time. The heat absorbing material 4Q is, for example, a powder material that separates water based on a chemical reaction when heated and exhibits an endothermic reaction. The heat absorbing material 4Q is, for example, formed of aluminum hydroxide (Al(OH)3) powder particles. The heat absorbing material 4Q is, for example, a powder crystal with a median particle size of about 10 μm to 100 μm.

[0027] Aluminum hydroxide is stable below 200°C, but in the temperature range of 200°C to 350°C, water molecules H2O are violently separated and decomposed to become Al2O3, and an endothermic reaction occurs at that time. The endothermic material 4T is formed to a layer thickness of, for example, 10 mm. Therefore, the third layer thickness of the third layer 4 is, for example, 20 mm. A fourth layer 5 is provided adjacent to the other surface 4B side of the third layer 4. The third layer 4 transfers heat in a second predetermined temperature range to the fourth layer 5.

[0028] The fourth layer 5 has one surface 5A facing the other surface 4B of the third layer 4. The other surface 5B of the fourth layer 5 is the non-heated surface facing the object to be protected K. The fourth layer 5 is made of the same material as the second layer 3. The fourth layer 5 is formed, for example, by stacking two layers of the same material as the second layer 3. Therefore, the fourth layer thickness is, for example, 26 mm, which is twice the second layer thickness of 13 mm. The fourth layer 5 is formed to have a fourth layer thickness that drops the heat transferred from the third layer 4 in the second predetermined temperature range to a third predetermined temperature range and transfers it to the object to be protected K. The third predetermined temperature range is set, for example, based on a predetermined standard so that the performance of the object to be protected K is maintained.

[0029] Next, a description will be given of a performance test of the fire-resistant wrapping structure 1. In the following performance test, the effect of the position of the third layer 4, which is the heat absorption layer, on the performance is compared.

[0030] FIG. 6 shows fire-resistant wrapping structure 1 and fire-resistant wrapping structures for comparison. No. 1 is fire-resistant wrapping structure 1. No. 2 is a comparison object in which the first layer 2, the fourth layer 5, the third layer 4, and the second layer 3 are layered in this order from the heated surface side. In No. 2, the third layer 4, which is a heat absorption layer, is located farther from the heated surface side than in No. 1. No. 3 is a comparison object in which the first layer 2, the third layer 4, the fourth layer 5, and the second layer 3 are layered in this order from the heated surface side. In No. 3, the third layer 4, which is a heat absorption layer, is located closer to the heated surface side than in No. 1. In the performance test, it is set to meet the pass criteria when the average temperature rise amount within each fire-resistant wrapping structure (i.e., the non-heated surface) is 139K or less and the maximum value is 181K or less.

[0031] Figure 7 shows a comparison of temperature changes in the layer thickness direction when the fire-resistant wrapping structures No. 1 and No. 2 are heated. As shown in the figure, the calculation results of temperature changes in 30-minute increments from 0 hours to 3 hours after heating are shown. The test calculates the temperature change of each layer when heating is performed for a predetermined fire resistance performance time (e.g., 3 hours) along the standard heating temperature curve of ISO834.

[0032] In the No. 1 fire-resistant wrapping structure 1, between 30 minutes and 3 hours, the first layer 2 transfers the heat generated by ignition to the second layer 3 with a first drop in temperature in a first predetermined temperature range of about 420°C to 640°C. The second layer 3 transfers the heat transferred from the first layer 2 to the third layer 4 with a second drop in temperature in a second predetermined temperature range of about 80°C to 280°C. The third layer 4 transfers the heat transferred from the second layer 3 to the fourth layer 5 in the second predetermined temperature range by an endothermic reaction.

[0033] The fourth layer 5 transfers the heat transferred from the third layer 4 to the non-heated surface side with a third drop in a second specified temperature range of approximately 20°C to 130°C. As a result, it was confirmed that No. 1 met the pass standard, with the average temperature rise of the non-heated surface after three hours being 112K. It was confirmed that the fire-resistant wrapping structure 1 of No. 1 was able to fully utilize the heat absorbing effect by keeping the temperature in the second specified temperature range in the third layer 4, which is the heat absorbing layer, by using up the chemical reaction of the heat absorbing material 4Q, as described below.

[0034] In contrast, in the comparative fire-resistant wrapping structure No. 2, between 30 minutes and 3 hours, the first layer 2 of the first layer reduces the heat generated by ignition in a predetermined temperature range of about 480°C to 750°C and transfers it to the fourth layer 5 of the second layer. The fourth layer 5 of the second layer transfers the heat transferred from the first layer 2 of the first layer to the third layer 4 of the third layer by reducing the temperature in a predetermined temperature range of about 50°C to 270°C. The third layer 4 of the third layer transfers the heat transferred from the fourth layer 5 of the second layer to the second layer 3 of the fourth layer by an endothermic reaction in the predetermined temperature range.

[0035] The fourth layer, second layer 3, transfers the heat transferred from the third layer, third layer 4, to the non-heated surface side by lowering the temperature within a second specified temperature range of approximately 25°C to 175°C. It was confirmed that the fire-resistant wrapping structure of No. 2 transfers less heat to the third layer 4, which is the heat absorption layer, compared to No. 1, and there are parts in the third layer 4 where no chemical reaction occurs in the heat absorption material 4Q, preventing the heat absorption effect from being fully exerted, resulting in a lower fire resistance performance compared to No. 1. As a result, it was confirmed that No. 2 did not meet the pass standard, with the average temperature rise on the non-heated surface after three hours having been 155°C.

[0036] With reference to the test results of No. 1, the fire-resistant wrapping structure of No. 3 is predicted to have a higher temperature rise than the temperature rise of the third layer 4 of the heat absorption layer in No. 1 when the third layer 4 of the heat absorption layer is adjacent to the first layer 2, and it is predicted that the endothermic reaction of the third layer 4 of the heat absorption layer will be insufficient (the endothermic material will be consumed early and the endothermic reaction will not continue for the specified time). Therefore, the configuration of No. 3 is not adopted for the fire-resistant wrapping structure.

[0037] According to the above test results, even if the same material is used, in order to maintain the temperature range on the non-heated side within the target temperature range, it is necessary to select a configuration that maintains the temperature range in which the heat absorbing material of the third layer 4, which is the heat absorbing layer, exerts its heat absorbing effect after a certain time has elapsed. According to the test results, it was confirmed that the fire resistance of the No. 1 configuration is higher than that of the No. 2 configuration.

[0038] In addition, it is desirable that the third layer 4 of the heat absorbing layer in the fireproof wrapping structure 1 has used up its ability to produce a heat absorbing effect when heated within the fireproof performance time (3 hours). Below, a performance test performed on the two layers of heat absorbing material 4T that make up the third layer 4 will be described. The performance test is, for example, simultaneous differential thermal and thermogravimetry analysis (TG-DTA). Simultaneous differential thermal and thermogravimetry analysis (TG-DTA) is a method in which the temperature of a sample and a reference substance are changed according to a program, while simultaneously measuring the weight change of the sample (Thermo Gravimetry: TG) and measuring the temperature difference between the sample and the reference substance (Thermo Gravimetry Analyzer: DTA).

[0039] FIG. 8 shows the TG-DTA test results for the two layers of heat absorbing material 4T that make up the third layer 4 of the fire-resistant wrapping structure 1. In the figure, the TG curve shows the weight change (wt%) of the sample versus temperature. A decrease in the TG curve indicates a decrease in weight. In the figure, the DTA curve shows the temperature change of the sample based on the thermocouple detection signal (μV) versus temperature. A decrease in the DTA curve indicates an endothermic reaction, and an increase in the DTA curve indicates an exothermic reaction. In the test, (1) a new heat absorbing material 4T, (2) heat absorbing material 4T placed on the heated surface after heating for three hours, and (3) heat absorbing material 4T placed on the non-heated surface after heating for three hours were used as samples, and each measurement was performed.

[0040] As shown in the TG curves, for (1), weight loss occurred due to a dehydration reaction. For (2), there was almost no weight loss, indicating that the performance had been fully utilized. For (3), there was a slight weight loss, but it was confirmed that the performance had been almost fully utilized. Also, as shown in the DTA curves, for (1), it was confirmed that an endothermic reaction occurred in a specified temperature range. For (2), no endothermic reaction was observed, indicating that the performance had been fully utilized. For (3), there was a slight endothermic reaction observed in a specified temperature range, indicating that the performance had been almost fully utilized.

[0041] From the test results, it was confirmed that the third layer 4 of the fire-resistant wrapping structure 1 fully exhibits fire resistance performance for the required fire resistance performance time (3 hours). In other words, when heat is transferred from the second layer 3 within a predetermined temperature range where the heat absorbing material exerts a heat absorbing effect, the third layer 4 can maintain the temperature within the predetermined range and transfer the heat to the fourth layer 5 based on the endothermic reaction of the heat absorbing material, three hours after the ignition.

[0042] Next, we will explain the performance test that evaluates the effect that differences in the material of the first layer in a fire-resistant wrapping structure have on fire resistance performance.

[0043] As shown in Fig. 9, the objects for comparison are fire-resistant wrapping structure No. 1 and fire-resistant wrapping structures No. 4 to No. 7. Fire-resistant wrapping structures No. 4 to No. 7 have a configuration in which the first layer 2 of fire-resistant wrapping structure 1 is formed from the same AES material as the second layer 3, but with different layer thicknesses.

[0044] Figure 10 shows the calculation results indicating the relationship between the number of each fireproof wrapping structure, the material and thickness of the first layer, and the temperature rise on the unheated side of the fourth layer after three hours of heating. As shown in the figure, in order to ensure that the fireproof wrapping structures No. 4 to No. 7 have the same level of fireproof performance as fireproof wrapping structure No. 1, it is necessary to form the thickness of the first layer of AES material to 35-40 mm, as in the configurations of No. 6 and No. 7. With fireproof wrapping structures based on the configurations of No. 6 and No. 7, the weight increases as the thickness of the AES material increases.

[0045] Figure 11 shows the temperature change in the thickness direction when the No. 7 fire-resistant wrapping structure is heated for a certain period of time. As shown in the figure, in order to ensure the same performance as the No. 1 fire-resistant wrapping structure 1 on the non-heated side, the thickness of the first layer of AES material needs to be four times thicker than the first layer 2 of the fire-resistant wrapping structure 1. Therefore, according to the No. 1 fire-resistant wrapping structure 1, by using a WDS material for the first layer 2, it is possible to reduce the weight compared to the No. 6 and No. 7 fire-resistant wrapping structures in which the first layer is made of AES material, and to improve the earthquake resistance of the equipment when applied to the protected object.

[0046] Next, we will explain the performance test to evaluate the effect that the difference in the material of the second layer in the fireproof wrapping structure has on the fire resistance performance. The fireproof wrapping structures No.1 (Fireproof wrapping structure 1), No.8, and No.9 were compared.

[0047] As shown in Fig. 12, the No. 8 fire-resistant wrapping structure has a configuration in which the layer thickness of the second layer 3 of the fire-resistant wrapping structure 1 is changed to 20 mm. The No. 9 fire-resistant wrapping structure has a configuration in which the second layer of the fire-resistant wrapping structure 1 is formed from the same first insulating material as the first layer 2 of the first layer.

[0048] Figure 14 shows the calculation results showing the relationship between the number of each fireproof wrapping structure, the material and thickness of the second layer, and the temperature rise on the non-heated side of the fourth layer after heating for three hours. As shown in the figure, in the fireproof wrapping structure No. 8, in which the layer thickness of the second layer 3 is thicker than the layer thickness of the second layer of fireproof wrapping structure 1 of No. 1, and in which the insulating material of the second layer is changed to WDS like the first layer 2, it was confirmed that the difference in performance is about the same. It was confirmed that the fireproof wrapping structure with the configuration of No. 8 has a thicker layer of the second layer than fireproof wrapping structure 1 with the configuration of No. 1, and that the weight increases. Therefore, if the performance is about the same, the configuration of No. 1, which has a relatively reduced weight, is adopted.

[0049] As shown in Figure 13, it was confirmed that the fire-resistant wrapping structure having the No. 9 configuration has the same level of performance as the fire-resistant wrapping structure 1 having the No. 1 configuration. The fire-resistant wrapping structure having the No. 9 configuration has a second layer formed of WDS, which makes it less flexible and less easy to work with compared to the No. 1 configuration. Therefore, if the performance is comparable, the No. 1 configuration is adopted, prioritizing workability.

[0050] As described above, the fire-resistant wrapping structure 1 can ensure fire resistance while reducing the weight by forming the first layer 2 to have higher thermal insulation than the second layer 3. The fire-resistant wrapping structure 1 can make the third layer 4, which is a heat absorption layer, exhibit a sufficient heat absorption effect during the required elapsed time after ignition by adjusting the first layer thickness of the first layer 2 and the second layer thickness of the second layer, which have different thermal conductivities, to predetermined layer thicknesses.

[0051] According to the fire-resistant wrapping structure 1, the temperature transferred by the heat generated on the heated surface side during the required elapsed time after ignition can be reduced to a temperature range on the non-heated surface side where the protected object can be protected. According to the fire-resistant wrapping structure 1, by adjusting the first layer thickness of the first layer 2 and the second layer thickness of the second layer 3, the second layer 3 can transfer heat in the second predetermined temperature range to the third layer 4, and the third layer 4 can use up its heat absorption effect within a predetermined fire resistance time (3 hours) after ignition.

[0052] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope of the invention described in the claims and their equivalents, as well as in the scope and gist of the invention. For example, in the fire-resistant wrapping structure 1, the heat-absorbing material 4Q of the third layer 4 may be formed of a powder material that separates water based on a chemical reaction when heated and shows an endothermic reaction, in addition to aluminum hydroxide, and may contain at least one of magnesium hydroxide, calcium hydroxide, calcium sulfate dihydrate, and magnesium sulfate heptahydrate. In addition, a fire-resistant paint may be applied to the heating surface side of the first layer 2 in the fire-resistant wrapping structure 1. [Explanation of symbols]

[0053] 1 Fireproof wrapping structure, 2 1st layer, 2A one side, 2B other side, 3 2nd layer, 3A one side, 3B other side, 4 3rd layer, 4A one side, 4B other side, 4Q Heat absorbing material, 5 4th layer, 5A one side, 5B other side, K Protection target

Claims

1. a first layer, one side of which is disposed on the ignition side and which is formed of a first insulating material having a first thermal conductivity; a second layer disposed adjacent to the other side of the first layer and made of a second insulating material having a second thermal conductivity higher than the first thermal conductivity; a third layer formed of a heat absorbing material and disposed adjacent to the other surface of the second layer; Between 30 minutes and 3 hours after the fire started, The first layer is formed to a first thickness for firstly lowering heat transferred from an ignition source to a first predetermined temperature range and transferring the heat to the second layer; the second layer is formed to a second thickness so as to lower the heat transferred in the first predetermined temperature range to a second predetermined temperature range in which the heat absorbing material exerts a heat absorbing effect, and transfer the heat to the third layer; the third layer maintains the heat in the second predetermined temperature range transferred from the second layer in the second predetermined temperature range based on an endothermic reaction of the heat absorbing material; The temperature of the ignition source progresses along the standard heating temperature curve specified in ISO 834, The first predetermined temperature range is 420° C. or more and 640° C. or less, The second predetermined temperature range is 80° C. or more and 280° C. or less, the thermal conductivity of the first layer in the first predetermined temperature range is equal to or greater than 0.02 W / m K and equal to or less than 0.04 W / m K; A fire-resistant wrapping structure, wherein the thermal conductivity of the second layer in the second predetermined temperature range is 0.03 W / m·K or more and 0.05 W / m·K or less.

2. a fourth layer, one side of which is provided adjacent to the other side of the third layer, which is made of the same material as the second layer and has an object to be protected arranged on the other side of the fourth layer; the fourth layer is formed to a fourth layer thickness such that the heat transferred in the second predetermined temperature range is third-times lowered to a third predetermined temperature range in which the protected object is maintained and transferred to the protected object; The fire-resistant wrapping structure of claim 1.

3. the first layer thickness and the second layer thickness are adjusted so that the second layer transfers heat in the second predetermined temperature range to the third layer during a predetermined fire resistance time after ignition, and the third layer uses up the heat absorption effect; The fire resistance performance time is 3 hours. The fire-resistant wrapping structure according to claim 1 or 2.

4. The heat absorbing material is formed of a powder material that separates water based on a chemical reaction when heated and exhibits an endothermic reaction. A fire-resistant wrapping structure according to any one of claims 1 to 3.

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