JP6186342B2 - Insulation cover manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a heat insulating cover that covers the periphery of a heat retaining object.

  Conventionally, for example, low-temperature pipes, low-temperature equipment, particularly heat insulation covers used in pipe cold insulation work related to LNG and LPG, are generally mainly made of polyurethane foam over the past 30 years. The performance is said to be limited to a thermal conductivity of about 0.02 W / mK at a normal temperature of 23 ° C. (see Patent Document 1).

JP 2001-108189 A

The conventional heat insulating cover described above needs to be thickened in order to reduce the amount of heat dissipated.
However, it is difficult to increase the construction thickness of the heat insulating cover without a margin space at the construction site, and there is a limit.
On the other hand, it is considered to use a vacuum heat insulating material with very good heat insulating performance, but the vacuum heat insulating material is usually inside a bag-like mat formed by a resin film in which a metal layer is laminated, Spacer member is provided to form a sealed space, and air is excluded from the sealed space. The vacuum insulation material alone has poor heat insulation at the periphery of the bag-like mat and is effective in covering the object to be kept warm. It is difficult to form the vacuum heat insulating material in a shape along the outer peripheral surface of the heat insulation object when there is a problem that the heat insulation area cannot be increased, or the outer peripheral surface of the heat insulation object has a complicated shape, for example.
Further, there is a weak point such that the bag-like mat is damaged due to contact with other objects during or after the heat insulation construction, the vacuum state inside is destroyed (vacuum breakage), and the heat insulation performance is rapidly lowered.
Therefore, a plate-shaped vacuum heat insulating material is integrally molded inside or outside the cover molded with foamed polyurethane, and on the surface of the vacuum heat insulating material opposite to the foamed polyurethane layer, FRP or the like for protection It is conceivable to prevent the vacuum insulation material from being broken by contact with other objects by bonding the fiber reinforced resin plate.
However, in this case, not only does the work of bonding with the adhesive take a lot of work, but air bubbles are likely to be mixed between the surface of the vacuum heat insulating material and the fiber reinforced resin plate, or gaps are likely to occur. Air bubbles such as bubbles and gaps swelled and the appearance deteriorates, and water vapor and moisture enter the air layer from the outside, resulting in a decrease in heat insulation performance.

  Accordingly, an object of the present invention is to provide a method for producing a heat insulating cover that can solve the above-mentioned problems and can cover the entire periphery of a heat insulation object while using the vacuum heat insulating material in a protected state.

  The characteristic configuration of the first heat insulating cover manufacturing method of the present invention is that the heat insulating object is divided into a plurality of parts in the circumferential direction of the heat insulating object to form divided covers, and each of the divided covers is configured to have a surface of the heat insulating object. A plate-like vacuum heat insulating material along or substantially along the shape is provided, a first foamed polyurethane layer is provided on the outer surface of the vacuum heat insulating material, and a second foamed polyurethane layer is provided on the inner surface of the vacuum heat insulating material. A manufacturing method for a heat insulating cover, wherein the whole peripheral surface of the vacuum heat insulating material is surrounded and integrated by the first foamed polyurethane layer and the second foamed polyurethane layer, and the outer peripheral surface of the divided cover; A first mold frame provided with an equivalent or substantially equivalent concave surface portion on the inside and a second mold frame provided with a convex surface portion equivalent or substantially equivalent to a part of the outer peripheral surface of the heat retaining object on the inside are prepared. The first formwork and the second formwork together. By making it possible, a split cover forming space capable of covering the split cover can be formed freely, and a concave surface portion of the first mold is provided with a height equal to or substantially equal to the thickness of the first foamed polyurethane layer. A first step of arranging a plurality of small foamed polyurethane first spacers in a state of being separated from each other, and a second step of placing the vacuum heat insulating material on the plurality of foamed polyurethane first spacers. And placing a second spacer having a thickness equivalent to or substantially equivalent to the second foamed polyurethane layer and capable of covering the entire inner surface of the vacuum heat insulating material on the vacuum heat insulating material. Injecting unfoamed polyurethane stock solution into the first space between the first mold formed by the third spacer and the first polyurethane foam spacer and the vacuum heat insulating material, and the first mold, Second type And a fourth step of foaming and curing the polyurethane stock solution in the divided cover forming space, a fifth step of removing the second spacer by separating the first mold frame and the second mold frame, and A sixth step of injecting an unfoamed polyurethane undiluted solution into a second space between the second mold frame and the vacuum heat insulating material formed by combining the first mold frame and the second mold frame again; And a seventh step of removing the divided cover from the divided cover forming space between the first mold and the second mold after the polyurethane stock solution is foam-cured.

According to the first characteristic configuration of the present invention, the vacuum heat insulating material is floated away from the concave surface portion of the first mold frame in the divided cover forming space by the first step and the second step. It can arrange | position stably and can inject | pour unfoamed polyurethane stock solution into the 1st space between a 1st mold and a vacuum heat insulating material.
Further, the third step and the fourth step prevent the unfoamed polyurethane undiluted solution from entering the second space between the vacuum heat insulating material and the second mold frame, and the gap between the first mold frame and the vacuum heat insulating material. The polyurethane stock solution injected into the first space can be uniformly foamed and filled, while the vacuum insulation material can be prevented from being displaced due to the foaming pressure of the polyurethane stock solution. The formed first polyurethane foam layer is self-adhered integrally.
In the sixth step after the fifth step, the second foamed polyurethane layer is formed inside the vacuum heat insulating material, and the vacuum heat insulating material and the second polyurethane layer are self-adhered during urethane foaming.
Finally, by the seventh step, the divided cover is taken out from the first mold frame and the second mold frame, and can be provided as a heat insulating cover for the heat retaining object.

  According to a second characteristic configuration of the present invention, the first polyurethane polyurethane spacer is cut out from molded polyurethane foam.

  According to the second characteristic configuration of the present invention, the first polyurethane foam spacer can be easily formed by cutting out from the molded foam polyurethane, and the first foam polyurethane layer integrated by foaming of the polyurethane stock solution and self-adhesion is provided. Easy to form.

  According to a third feature of the present invention, before injecting the unfoamed polyurethane stock solution, a waterproof or moisture-proof first sheet is temporarily fixed to the concave surface portion of the first mold, and the first A waterproof or moisture-proof second sheet is temporarily fixed to the convex surface portion of the two-frame.

  According to the third characteristic configuration of the present invention, before injecting the unfoamed polyurethane stock solution, temporarily fixing the waterproof or moisture-proof first sheet to the concave surface portion of the first mold, By temporarily fixing a waterproof or moisture-proof second sheet to the convex surface portion of the second mold, the waterproof or moisture-proof first sheet and the waterproof or moisture-proof second sheet are provided. A split cover that is integrally bonded to the outer peripheral surface can be easily formed, and a heat insulating cover that has good waterproofness or moisture resistance and is easy to maintain heat insulating performance can be formed.

It is a disassembled perspective view before the assembly construction of the heat insulation cover attached with respect to a heat retention object. It is a perspective view after the assembly construction of the heat insulation cover with respect to a heat retention object. It is radial direction sectional drawing of a division | segmentation cover. FIG. 4 is an end radial direction sectional view of the divided cover, (a) is an enlarged view of FIG. 3, and (b) is an end radial direction sectional view of the divided cover when there is a seal portion around the bag-like mat. . (A) is radial direction sectional drawing of the 1st formwork of a 1st process, (b) is a perspective view of a 1st process. (A) is radial direction sectional drawing of the 1st formwork of a 2nd process, (b) is a perspective view of a 2nd process. (A) is radial direction sectional drawing of the 1st moldwork of the 3rd, 4th process, (b) is a perspective view of the 3rd, 4th process. (A) is radial direction sectional drawing of the 1st, 2nd moldwork of a 6th process, (b) is a perspective view of a 6th process. (A) is radial direction sectional drawing of the 1st formwork of a 7th process, (b) is a perspective view of a 7th process. It is assembly | attachment sectional drawing of the heat insulation cover of another embodiment. It is an assembly perspective view of the heat insulation cover of another embodiment. It is the assembly | attachment longitudinal cross-sectional view of the heat insulation cover of another embodiment.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1, 2, 3, and 4 (a), for example, a heat insulating cover for a fluid circulation pipe as a heat retaining object 1 is configured.
That is, the semi-cylindrical divided cover 2 is formed by dividing into two in the circumferential direction of the fluid circulation pipe.
Each of the divided covers 2 is provided with a spacer member 4 inside a bag-like mat 3 formed of a resin film laminated with a metal layer such as an aluminum foil to form a sealed space, and air is excluded from the sealed space. Then, a semi-cylindrical plate-like vacuum heat insulating material 5 along or substantially along the surface shape of the fluid circulation pipe is provided, and the first foamed polyurethane layer 6 is attached to the outer surface of the vacuum heat insulating material 5; A second foamed polyurethane layer 7 is provided on the inner side surface of the vacuum heat insulating material 5, and the entire peripheral surface of the vacuum heat insulating material 5 is surrounded by the first foamed polyurethane layer 6 and the second foamed polyurethane layer 7. The first and second foamed polyurethane layers 7 are integrated by the self-adhesive force of urethane when forming.
In addition, asphalt felt is bonded as a waterproof layer 8 to the surface different from the bonding surface with the vacuum heat insulating material 5 in the first and second foamed polyurethane layers 6 and 7, and moisture from the outside to the foamed polyurethane layer. Intrusion of water is prevented and deterioration of heat insulation performance is prevented.
The waterproof layer 8 should be at least waterproof, but if an aluminum foil laminate sheet is used, the waterproof layer 8 has not only waterproofness but also moisture resistance, and can prevent water vapor from entering outside of moisture from the outside. As a function can be expected.

(Second embodiment)
As shown in FIG. 11, a pair of first divided covers 2A and a pair of second divided covers 2B, in which a heat insulating cover is doubled on the outside of the heat insulation object 1 made of piping and the piping is doubled, are divided. The positions of the joint joints at the circumferential ends of the covers are arranged differently to prevent heat leakage from the joint joint, and on the first sheet 8A of the first divided cover 2A located outside. Uses a highly waterproof and moisture-proof aluminum laminate sheet, and the second sheet 8B of the first divided cover 2A and the first sheet 8A and the second sheet 8B of the second divided cover 2B are breathable. In addition, by using asphalt felt that is waterproof, intrusion of dew condensation water generated in the pipe periphery while preventing intrusion of water vapor and water from the atmosphere with the aluminum laminate sheet of the first sheet 8A, Scan asphalt felt are to be able to stop in.

(Production method)
A method for manufacturing each of the divided covers 2 will be described in the following order of steps as shown in FIGS.
1. A first mold 10 having a semi-cylindrical concave surface portion 9 that is the same as or substantially equivalent to the outer peripheral surface of the divided cover 2 and a semi-cylindrical shape that is equivalent or substantially equivalent to a part of the outer peripheral surface of the fluid circulation pipe. The first mold 10 and the second mold 12 are prepared by preparing the second mold 12 having the convex surface portion 11 on the inner side and combining the first mold 10 and the second mold 12. 12, a split cover forming space capable of covering the semi-cylindrical split cover 2 can be formed freely.
Asphalt felt is installed on the concave surface portion 9 inside the first mold 10 as the first sheet 8A for forming the waterproof layer 8, and the height is equal to or approximately the same as the thickness of the first foamed polyurethane layer 6. A first spacer 13 made of polyurethane foam having a thermal conductivity of 0.024 W / mK (40 mm thick) is cut out from the molded polyurethane foam, and the first spacers 13 are separated from each other. A first step (FIG. 5 (a) in which a plurality of pieces are arranged on the asphalt felt installed on the concave surface portion 9 of the one-frame 10 so as to be fixed via a one-component rubber adhesive. ), (B)).
The first spacer 13 may have a flat shape, but the front and back surfaces are curved along the concave surface 9 of the curved first mold 10, and the vacuum heat insulating material 5 is stably held in position. In this case, the first mold 10 is used to cut out a foam-molded one having the same curvature as the first mold 10.

2. In order to form a vacuum space by filling the inside of the bag-like mat 3 formed of a resin film laminated with aluminum foil with a spacer member 4 made of glass fiber to eliminate air from the internal space of the bag-like mat 3. The entire periphery is sealed to form a sealed space. A second step of placing the vacuum heat insulating material 5 (thickness 10 mm) having a thermal conductivity of 0.0025 W / mK constituted by the bag-like mat 3 on the plurality of first polyurethane foam spacers 13 (FIG. 6A ), (B)).
Note that the vacuum heat insulating material 5 is bent in advance into a partially cylindrical plate shape along or substantially along the surface shape of the fluid circulation pipe, and when the flange-like seal portion 14 is present in the entire peripheral portion. As shown in FIG. 4 (b), it is folded inward so that it does not protrude from the periphery of the split cover 2.

3. A semicircular arc-shaped second spacer 15 having a thickness equal to or substantially the same as the second foamed polyurethane layer 7 and capable of covering the entire inner surface of the vacuum heat insulating material 5 is previously molded from foamed polyurethane. Then, the 3rd process (FIG. 7 (a), (b)) mounted on the vacuum heat insulating material 5. FIG.
Note that a release material is applied to the periphery of the second spacer 15.

4). An unfoamed polyurethane undiluted solution is injected into the first space between the first mold 10 formed by the first polyurethane foam spacer 13 and the vacuum heat insulating material 5, and the first mold 10 and the second mold 12. And the polyurethane undiluted solution is heated at 30 to 35 ° C. for 45 minutes to 50 minutes in a split cover forming space partially having an air escape portion, and then foamed and cured in a fourth step (FIG. 7 (a ), (B)).
A release paper 16 is attached to the convex surface portion 11 of the second mold 12 so that the second spacer 15 does not adhere to the second mold 12 in advance by foaming polyurethane.

5. A fifth step of separating the first mold 10 and the second mold 12 to remove the release paper 16 from the second mold 12 and removing the second spacer 15 from the inside of the semi-cylindrical vacuum heat insulating material 5. .

6). Asphalt felt is temporarily attached to the convex surface portion 11 of the second mold 12 as the second sheet 8B for forming the waterproof layer 8, and the first mold 10 and the second mold 12 are combined again. A sixth step of injecting an unfoamed polyurethane stock solution into the second space between the second mold 12 and the vacuum heat insulating material 5 (FIGS. 8A and 8B).
The second mold 12 is provided with a mounting portion 17 for temporarily fixing the release paper 16 and the second sheet 8B.

7. Heat to 30 to 35 ° C. for 45 to 50 minutes, and after foaming and curing the polyurethane stock solution, from the divided cover forming space between the first mold 10 and the second mold 12 to a thickness of about 100 mm The molded divided cover 2 is taken out, and the circumferential end and the longitudinal end of the divided cover 2 are cut off to a predetermined size (FIG. 9A, FIG. 9B). )).

[Another embodiment]
Other embodiments will be described below.
<1> As the heat retaining object 1, not only a fluid circulation pipe but also a cylindrical fluid storage tank, a valve connected to the pipe, or the like may be a target. In addition to being divided into two parts in the direction, the divided cover 2 can be easily formed by dividing it into three or more parts. Moreover, in order to keep the temperature of the object to be kept warm, the heat insulation includes the cold preservation, and the relative temperature difference from the outside air may be a positive value or a negative value, and both cases are included. . For example, the fluid flowing through the fluid distribution pipe includes both a warm fluid and a cold fluid.
<2> In order to constitute the vacuum heat insulating material 5, an inorganic powder or the like other than glass fiber may be used as the spacer member 4 provided in the bag-like mat 3. That is, it is only necessary to secure a vacuum space.
<3> A plurality of the vacuum heat insulating materials 5 may be stacked and embedded in the divided cover 2.
<4> When the divided cover 2 covers the entire peripheral surface of the heat retaining object 1 such as piping by a plurality of combinations, as shown in FIG. 10, the fitting portion at the edge in the circumferential direction of the divided cover 2 In this case, the plurality of vacuum heat insulating materials 5 may be arranged so as to be polymerized in the radial direction and integrally molded with the polyurethane foam layer to reduce heat leakage as much as possible to improve the heat insulating performance.
<5> The plurality of divided covers 2 have a longitudinal section cut along the longitudinal direction of the pipe, as shown in FIG. If adjacent parts are fitted together so that the ends of the vacuum heat insulating material 5 overlap each other in the radial direction, if the interior is within the wall thickness of the split cover 2, further heat in the longitudinal direction of the pipe Leakage is prevented and heat insulation performance is improved.
<6> In order to fix the first spacer 13 to the asphalt felt or the vacuum heat insulating material 5, in addition to the rubber adhesive, a urethane adhesive may be used.

  In addition, as mentioned above, although the code | symbol was written in order to make contrast with drawing convenient, this invention is not limited to the structure of an accompanying drawing by this entry. In addition, it goes without saying that the present invention can be carried out in various modes without departing from the gist of the present invention.

2 Divided Cover 3 Bag-shaped Mat 4 Spacer Member 5 Vacuum Heat Insulating Material 6 First Foam Polyurethane Layer 7 Second Foam Polyurethane Layer 8 Waterproof Layer 8A First Waterproof Layer Forming Sheet 8B Second Waterproof Layer Forming Sheet 9 Concave Surface 10 1st formwork 11 Convex surface part 12 2nd formwork 13 1st spacer 15 2nd spacer

Claims (3)

Dividing into multiple pieces in the circumferential direction of the thermal insulation object to form a divided cover,
To configure each of the divided covers,
While providing a plate-like vacuum heat insulating material along or substantially along the surface shape of the heat retaining object,
A first foamed polyurethane layer is provided on the outer side surface of the vacuum heat insulating material, and a second foamed polyurethane layer is provided on the inner side surface of the vacuum heat insulating material, and the entire peripheral surface of the vacuum heat insulating material is provided on the first foamed polyurethane layer. A method for manufacturing a heat insulating cover surrounded by a layer and a second foamed polyurethane layer,
A first mold frame provided with a concave surface portion equivalent or substantially equivalent to the outer peripheral surface of the divided cover on the inside, and a convex surface portion equivalent or substantially equivalent to a part of the outer peripheral surface of the heat retaining object provided on the inner side. By preparing a second formwork and combining the first formwork and the second formwork, it is possible to freely form a divided cover forming space that can cover the divided cover,
A plurality of small foamed polyurethane first spacers having a height equal to or substantially the same as the thickness of the first foamed polyurethane layer are disposed on the concave surface portion of the first formwork so as to be separated from each other. A first step of
A second step of placing the vacuum heat insulating material on a plurality of foamed polyurethane first spacers;
A third step of placing on the vacuum heat insulating material a second spacer having a thickness equivalent to or substantially equal to the second foamed polyurethane layer and capable of covering the entire inner surface of the vacuum heat insulating material. When,
An unfoamed polyurethane undiluted solution is injected into a first space between the first mold frame formed by the first polyurethane foam spacer and the vacuum heat insulating material, and the first mold frame and the second mold frame And a fourth step of foaming and curing the polyurethane stock solution in the divided cover forming space,
A fifth step of removing the second spacer by separating the first mold and the second mold;
A sixth step of injecting an unfoamed polyurethane undiluted solution into a second space between the second mold frame and the vacuum heat insulating material formed by combining the first mold frame and the second mold frame again; ,
And a seventh step of removing the divided cover from the divided cover forming space between the first mold and the second mold after the polyurethane stock solution is foam-cured.   The method for manufacturing a heat insulating cover according to claim 1, wherein the first polyurethane foam spacer is cut from molded foam polyurethane.   Before injecting the unfoamed polyurethane stock solution, a waterproof or moisture-proof first sheet is temporarily fixed to the concave surface portion of the first mold and waterproofed to the convex surface portion of the second mold The manufacturing method of the heat insulation cover of Claim 1 or 2 which temporarily fixes the property or moisture proof 2nd sheet | seat.

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