JPH0318802B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for insulating an object to be insulated with an internal temperature of -190 to 140°C, such as a liquefied natural gas tank or a transport pipe.

[Conventional technology]

Conventionally, a heat insulating foam resin material such as polyurethane foam, which is pre-fabricated in a factory in a shape that follows the outer periphery of the object to be insulated, such as a tank or pipe, is attached to the object to be insulated. Insulation can be achieved by forming a foamed resin layer to provide insulation, or by coating or spraying a foaming solution such as polyurethane foam on the outer peripheral surface of the object to be insulated, as shown in Japanese Patent Application Laid-Open No. 156598/1983. A method of insulating the object by forming a foamed resin layer around the outer circumference of the object was adopted.

[Problem that the invention seeks to solve]

However, when using the former method, the insulation foam resin layer is formed using a factory-produced insulation foam resin material, so the insulation foam resin material is bulky and the cost of transporting it to the site is high. It has the disadvantage that it cannot be avoided from being broken during transportation, which increases costs, and that gaps tend to form between the object to be insulated and the insulating foam resin material attached to it, resulting in poor insulating performance. In addition, when using the latter method, since foam molding is performed in the outside air, the foam molding is greatly affected by the outside air temperature, and as a result, the density is not constant, making it extremely difficult to stabilize the quality of the foamed resin layer for heat insulation. Moreover, it is difficult to finish the surface of the heat insulating foam resin layer into a predetermined shape, making it difficult to attach exterior materials etc. afterwards.

An object of the present invention is to provide a heat insulation method that allows stable foam molding of a foamable resin material for heat insulation without being affected by outside temperature, and that also allows easy attachment of exterior materials.

[Means for solving problems]

The technical means of the present invention taken to achieve the above object include a formwork installation step for installing a formwork for forming a heat insulating foam resin layer on the outside of an object to be insulated, and a formwork installation step for heating the foamable resin material. In a heat insulation method that combines the following steps: a heat generation step for forming a heat insulating foam resin layer, and a foamable resin material injection step for injecting a foamable resin material into a space for forming a foamed resin layer for heat insulation, the following steps [A] to [D] It is equipped with the configuration described in .

[B] In the formwork installation step, a heat-generating sheet that generates heat when energized is used as a formwork constituent material, and a spacer with a size corresponding to the thickness and width of the heat-insulating foam resin layer to be formed on the outer surface of the object to be heat-insulated is used. A heat-generating sheet having a shape that follows the external shape of the heat-insulating object is installed in a state that constitutes a formwork surface for surrounding the heat-insulating object.

[B] In the heat generation step, the space between the object to be insulated and the heat generating sheet that generates heat when energized is heated to a required temperature by energizing the heat generating sheet.

[C] In the foamable resin material injection step, a foamable resin material is injected into a space for forming a heat insulating foam resin layer between the heat insulating object and the heat generating sheet.

[D] After the heat generating sheet installation process is completed, a heat generating process and a foaming resin material injection process are started,
A heat insulating foam resin layer is formed between the heat insulating object and the heat generating sheet, and the heat generating sheet is attached to the outer surface of the heat insulating foam resin layer.

[Effect]

The effects of taking the above technical measures are as follows.

a) Since the foamed resin layer for heat insulation is formed by foam molding on site, the bulk of the materials carried to the site can be reduced, and the foamed resin layer for heat insulation can be brought into close contact with the object to be insulated immediately.

b The space for foaming the foamable resin material is isolated by the formwork components, and the formwork components themselves generate heat, making it possible to freely control the temperature within the space. It is easy to adjust the temperature inside to a temperature suitable for foam molding.

c. Since the formwork constituent material is located on the outer surface of the foamed resin layer for heat insulation, there is no need for finishing work to correct irregularities on the outer surface of the foamed resin layer for heat insulation.

〔Effect of the invention〕

The effects described in a to c above have the effect that a foamed resin for heat insulation, which has excellent heat insulation performance and is easy to attach to the exterior material, can be economically formed around the outer periphery of the object to be insulated. .

〔Example〕

Examples of the method of the present invention will be described below. The heat insulation method of the present invention includes a formwork installation step for installing a formwork for forming a foamed resin layer for insulation on the outside of an object to be insulated, a heat generation step for heating a foamable resin material, and a foaming step for forming a foamed resin layer for insulation. It is configured by combining each step of a foamable resin material injection step of injecting a foamable resin material into the resin layer forming space.

First, in the formwork installation step, as shown in Figs.
(glass cloth, ceramic sheet, etc.), and the outer periphery of this heat-insulating acid-resistant sheet 2 is covered with a first heat-generating sheet 3, while a foamed phenolic resin layer A for heat insulation to be formed on the outer periphery of the pipe 1.
The second heat generating sheet 4 is inserted into the pipe via a plurality of phenolic resin spacers 5 positioned at appropriate intervals in the circumferential direction and longitudinal direction of the pipe so as to constitute the entire mold surface for molding the outer circumferential surface of the pipe. 1
It is supported by In other words, the second heat generating sheet 4 is used as a formwork member for forming a space for forming a heat insulating foam resin layer between the second heat generating sheet 4 and the pipe 1. After the formwork installation process is completed, each process includes a heat generation process for heating the foamable resin material and a foamable resin material injection process for injecting the foamable resin material into the space for forming a foamed resin layer for heat insulation. I do. First, in the heat generation step, the first and second heat generation sheets 3 and 4 that generate heat when energized are used to heat the space between the heat generation sheets 3 and 4 to a required temperature. (about 40-50℃).

Of the two heat generating sheets 3 and 4, the first heat generating sheet 3 is used as an auxiliary means for heating the space for forming the heat insulating foam resin layer.

A foamable resin material injection step is started in which the foamable resin material is injected into the space for forming a heat insulating foamed resin layer while the heat generation step is continued in a state where the material is heated to the required temperature. In this foamable resin material injection step, phenolic resin (an example of a foamable resin material) is injected into the space through the holes 4a formed in the second heat generating sheet 4 and foamed.

After injecting the foamable resin material, rise time (2
~5 minutes), the heating temperature of both heat-generating sheets 3 and 4 is raised to 80~95°C and heated for the required time (about 2~5 minutes), thereby forming a layer of foamed phenolic resin on the outer periphery of the pipe 1. Form A and pipe 1
Insulate.

Both heat generating sheets 3 and 4 are appropriately joined by well-known means such as adhesive to form a cylindrical shape.
Even after the resin layer A is formed, it remains attached to the inside and outside of the resin layer A, so that the installation location of the insulation object is not exposed to wind, rain, oil, or chemicals. Depending on the situation, such as under certain conditions, an appropriate exterior material may be attached to the outer surface of the outer second heat generating sheet 4 as necessary, but the installation conditions are not poor and a particularly strong exterior material is not required. In this case, the second heat generating sheet 4 itself may be used as an exterior material in order to prevent deterioration of the internal heat insulating foam resin layer A.

In addition, both of the heat generating sheets 3 and 4 are constructed by interposing a plurality of heat generating wires 6 (stainless steel thread, etc.) that generate heat when energized between two polyvinyl alcohol transparent sheets with a heat-resistant temperature of about 200°C. However, as this heat generating sheet,
Appropriately known ones, for example, JP-A-56-143693, JP-A-57-47694, JP-A-57-87088, JP-A-58-1990, JP-A-58-28331
What is necessary is to use the one shown in the No. 3 publication.

The above-mentioned phenolic resin is, for example, one obtained by mixing freon with a benzyl ether type phenolic resin at 23° C. or lower and adjusting the temperature of the whole to 20° C., and then adding a curing agent and a regulating agent at 20° C.

According to the above embodiment, not only can the temperature be controlled by heating by both heat generating sheets 3 and 4 to cause foaming to occur appropriately, but since the second heat generating sheet 4 is transparent, foaming can be observed visually. Moreover, since phenolic resin is used as a foamable resin, for example, when polyurethane resin is used, its structure deteriorates over time and its insulation performance decreases, and it decomposes due to combustion and generates gas. There is very little to do.

[Another example] Applicable to insulation of tanks and equipment.

As the foamable resin, a resin other than phenol resin, such as polyurethane resin, is used.

The heat generating sheet 4 is supported by a formwork located outside of the heat generating sheet 4.

In the embodiment, when the foaming pressure is high, a reinforcing band is wrapped around the outer periphery of the second heat generating sheet 4 in order to prevent the second heat generating sheet 4 from deforming due to the foaming pressure.

The heat generating sheet 4 partially constitutes the mold surface.

The heat generating sheet 4 is made of resin and generates heat when energized.

It is carried out by mixing filler such as glass fiber with foamable resin.

[Brief explanation of drawings]

1 and 2 are a cross-sectional view and a partially cutaway side view showing an embodiment. 1... Insulating object, A... Foamed resin layer for heat insulation,
4... Heat generating sheet, 5... Spacer, 6... Heat generating wire.

Claims (1)

[Claims] 1. A formwork installation step for installing a formwork for forming a heat insulating foam resin layer on the outside of the insulation object 1, a heat generation step for heating the foam resin material, and a heat insulating step for forming a foam resin layer. The insulation is constructed by combining the steps of injecting a foamable resin material into the space for forming a foamed resin layer, and has the configurations described in [A] to [D] below. Method. [B] In the formwork installation step, a heat generating sheet 4 that generates heat when energized is used as a formwork constituent material, and a dimension corresponding to the thickness and width of the heat insulating foam resin layer A to be formed on the outer surface of the heat insulating object 1 is used. A heat-generating sheet 4 having a shape that follows the outer shape of the heat-insulating object 1 is placed in a state that constitutes a formwork surface for surrounding the heat-insulating object 1 via a spacer 5 . [B] In the heat generation step, the space between the heat-insulating object 1 and the heat-generating sheet 4 that generates heat when energized is
By applying electricity to the heat generating sheet 4, it is heated to a required temperature. [C] In the foamable resin material injection step, a foamable resin material is injected into the space between the heat insulating object 1 and the heat generating sheet 4 for forming the heat insulating foam resin layer A. [d] After the installation process of the heat generating sheet 1 is completed, a heat generating process and a foaming resin material injection process are started to form a heat insulating foam resin layer A between the heat insulating object 1 and the heat generating sheet 4, The heat generating sheet 4 is attached to the outer surface of the heat insulating foam resin layer A. 2. The heat insulation method according to claim 1, wherein the heat generating sheet 4 is constructed by interposing a plurality of heat generating wires 6 that generate heat when energized between two heat-resistant films. 3. The heat insulation method according to claim 1 or 2, wherein the heat generating sheet 4 constitutes the entire mold surface. 4. The heat insulation method according to claim 1 or 2, wherein the heat generating sheet 4 constitutes a part of the mold surface. 5. The heat insulation method according to any one of claims 1 to 4, wherein the foamable resin material is a phenolic resin.