JPS6194748A - Manufacture of heat-insulating pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a heat insulating pipe in which a filler is filled between a base pipe and an armored pipe.

(Prior Art) A heat-insulating pipe in which a foamed resin is filled as a filler between a base pipe and an exterior pipe is well known. Such a heat-insulated pipe is disclosed in Japanese Patent Application Laid-Open No. 1986-
As disclosed in Japanese Patent No. 17743, after attaching the base tube provided with the support to the exterior tube and attaching tube end closing plates to close both ends of the space between the base tube and the exterior tube, the above-mentioned It is obtained by filling the foamed resin through a nozzle inserted into the space and pulling the nozzle outward to complete the filling, and then removing the tube end closing plate.

(Problems to be Solved by the Invention) However, when an inorganic foaming material is used as a filler, there is no circulation around the foaming agent, and the foaming ratio is 1.
Since it is about 5 to 3 times as low (about 20 times with conventional synthetic resin foaming agents), unfilled areas tend to occur between the base tube and the outer tube, which poses a problem in terms of strength.

Note that the inorganic foaming agent is used to significantly improve heat resistance and fire resistance. Conventionally used synthetic resin foam materials, such as urethane foam, have a heat resistance temperature of 1.
00℃ or less, while inorganic materials have a temperature of 300℃
In addition, the conventional type was unfavorable in terms of disaster prevention because it easily burned due to external flames in the event of a fire.

In view of the paper problem, the present invention aims to provide a method for manufacturing an insulated pipe that does not cause incompletely filled parts even when an inorganic foaming agent with poor fluidity and a low expansion ratio is used as a filler. It was done for a purpose.

(Failure to solve the problem) The following measures will be taken to achieve the above objectives.

In other words, when filling the space between the base tube and the exterior tube with the filler material, the exterior tube is attached to the base tube while filling the outer periphery of the base tube, which is provided with a support for supporting the exterior tube, with the filler material. be.

(Example) FIG. 2 shows a first example of a heat insulating pipe 1 manufactured according to the present invention. The heat insulating pipe 1 includes a supply pipe 4, a ring-shaped support 5 appropriately provided on the outer peripheral surface of the supply pipe 4, and a heat insulating material 6 attached to the outer peripheral surface of the supply pipe 4 between the supports 5. A synthetic resin coating 8 is applied to the base tube 2, which is made up of 7 is filled.

The support 5 and the heat insulating material 6 are made of an inorganic heat insulating material such as calcium silicate or water-repellent pearlite, and are attached to the supply pipe 4 via an inorganic adhesive made of the same material as the heat insulating material 6. It is being

Further, the abutting surfaces of the support 5 and the heat insulating material 6 are also sealed with the adhesive.

The support has the function of positioning the base tube 2 concentrically with the exterior tube 3, and also serves as a guide when attaching the exterior tube 3 to the base tube 2. Furthermore, the support has the function of positioning the base tube 2 concentrically with the exterior tube 3, and also serves as a guide when attaching the exterior tube 3 to the base tube 2.
It acts as a leak-preventer.

For this reason, one to several pieces are attached to both ends and midway of the supply pipe 4. Incidentally, even if a gap occurs between the outer circumferential surface of the support 5 and the inner circumferential surface of the exterior tube 3, there is no problem because the gap is tightly filled with the filler material 7.

The outer peripheral surface of the base tube 2 is covered with synthetic resin waves 11j! 8 is applied to improve the adhesion between the heat insulating material 6 and the filler 7. The synthetic resin coating 8 is made of modified acrylic resin, silicone resin, or the like, and when the filler 7 is in a liquid state immediately after being supplied, it prevents the solvent in the filler from being absorbed into the heat insulating material 6, etc. It acts to ensure foaming.

As the exterior pipe 3 attached to the base pipe 2, a zinc spiral duct, a colored zinc spiral duct thin-walled steel pipe, etc. are used.

Next, a method of manufacturing such a heat insulating pipe 1 will be explained with reference to FIG.

First, the supply pipe 4 is inserted horizontally into the stand 11, and
The base pipe 2 is created by attaching the support 5 and the heat insulating material 6 to the supply pipe 4 using the same inorganic adhesive as these materials. The support 5 and the heat insulating material 6 may be a cylindrical integral body, or may be divided into pieces.

Next, a synthetic resin coating 8 is applied to the outer peripheral surface of the heat insulating material 6 and cured (the synthetic resin coating 8 is not shown in FIG. 1).
. Alternatively, the synthetic resin film 8 may be applied to the outer peripheral surface of the heat insulating material 6 and cured in advance, and then the heat insulating material 6 may be attached to the supply pipe 4.

The filler 7 is an inorganic foam material, and is applied with silica sol stored in a chemical tank A controlled at 20±5° C. by a warmer 12 and foam base powder stored in a chemical tank B. Sometimes mixed and formed. The inorganic foam material includes 18-t% of silica sol and 82% of foam base powder in terms of solidification.
-t% (cement binder 34wt%, silica fine powder 2
2wt%, perlite 9wt%, glass fiber 14-t%
, foam material (3 wt%) can be exemplified. When both are mixed, they start foaming, and it takes about several lθ minutes to complete foaming. Thereafter, it is cured to form a porous heat insulating layer made of silica-alumina composite oxide. In FIG. 1, S is a screw conveyor for powder transfer, P is a supply pump, and M is a mixing head.

The liquid filler mixed and formed at the time of application is transferred to the mixing head M while inserting the outer tube 3 into the base tube 2 using the trolley 13.
The gap between the base tube 2 and the exterior tube 3 is filled while moving together with the exterior tube 3. Although the trolley 13 is not necessarily necessary, it is effective when the insulating pipe has a large diameter. It is preferable to provide a tray 14 at the front end of the lower part of the outer tube 3 to prevent the filling material from falling. The receiver plate 14 is removed after the outer tube 3 is attached. When installing the outer tube 3, the support 5 serves as a guide and is suitable for easy insertion. In this way, by filling the filler while inserting the outer tube 3, the gap between the base tube 2 and the outer tube 3 can be filled according to the expansion ratio of the filler (1.5 to 3 times in this example). Since you can install the optimal amount while checking the condition, there will be no unfilled parts. Note that the mixing head M and its tip nozzle are washed with water after use in preparation for the next filling.

After the outer tube 3 is attached, curing is performed for about 10 hours to obtain the desired heat insulating tube 1.

FIG. 3 shows a second embodiment of a heat insulating pipe 1a manufactured by the method of the present invention. In the second embodiment, the base pipe 2a is a heating supply pipe 16 in which a heating pipe 15 is disposed diagonally below the supply pipe 4a and a heat insulating material 6 and a support (not shown) are provided, and a heat insulating pipe 1a is used. It was formed.

FIG. 4 shows the third section of the insulated pipe 1b manufactured according to the present invention.
This is an example in which the base pipe 2b is formed using only a supply pipe 4b and a support (not shown).

(Effects of the Invention) As explained above, according to the present invention, since the exterior tube is attached to the base tube while filling the outer periphery of the base tube with the filler, a material with poor fluidity and foamability is used as the filler. Even when filling the gap between the outer tube and the base tube, it is possible to fill the space while checking the filling state, and it is possible to easily fill the optimal amount of filler according to the expansion ratio. Further, since the base tube is provided with a support for supporting the outer tube, this support can be used as an insertion guide when the outer tube is attached, and the filling operation can be performed extremely easily.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway sectional view showing a manufacturing example of the present invention, FIGS. 2 to 4 are cross-sectional views of a heat insulating pipe manufactured by the manufacturing method of the present invention, and FIG. 2 is a support and heat insulating material. Fig. 3 shows the base pipe with a heating supply pipe with support and heat insulating material attached, and Fig. 4 shows the supply pipe with only the support attached. This is the base pipe. L lal 1b --- Gosho Netsukan, 2.2a, 2b-
Base tube, 3-exterior tube, 5-support, 7-filling material.

Claims (1)

[Claims] 1. When filling the filler between the base pipe and the outer pipe,
A method for manufacturing a heat insulating pipe, comprising: filling the outer periphery of a base pipe provided with a support for supporting the sheathing pipe with a filler, and attaching the sheathing pipe to the base pipe.