JPH01204729A - Heat insulation pipe and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a heat insulation pipe through which a degree of heat insulation is adjustable, by a method wherein an electric heating sheet obtained by holding electric heating wire between thermosetting solvent welding rubber sheets is stuck close to the outer circumference of a pipe for joining. CONSTITUTION:When a silicon raw rubber sheet 21 which is reinforced with glass cloth and put on a mold 1 is pressurized and heated, a positioning pin 6 is sunk downward, joined to a silicone raw rubber sheet 21 forming a thermosetting solvent welding rubber sheet and transferred by keeping a shape of an electric heating wire 20 on the mold 1 as it has been wired. In continuation, when the silicone raw rubber sheet 21 is turned over, one more silicone raw rubber sheet 22 is put over the sheet 21 and pressurization and heating are performed with a hot press, they are stuck together under a state where the electric beating wire 20 is held by placing between them. Then a planar electric heating sheet 26 can be formed by putting the silicone raw rubber sheet piece 25 on a terminal sheet 23 after connection of a lead wire 24 with the electric heating wire 20 and pressurization and by heating the piece with the hot press. A degree of heat insulation can be controlled freely through heating of the electric heating wire like this and a homogeneous heat insulation pipe can be formed easily by reducing field operation through factory production.

Description

[Detailed description of the invention] "Industrial application field" The present invention is an iron #l manufacturing equipment that requires a heat retention process.

The present invention relates to a heat-retaining pipe for keeping fluid flowing in a pipeline warm in chemical manufacturing equipment or other arbitrary equipment, and a method for manufacturing the same.

``Conventional technology'' Conventionally, in order to keep the fluid in a pipeline warm, a heat insulating material was wrapped around the outer circumference of the pipes that make up the pipeline. Since there are bent pipes and different parts require heat insulation, wrapping the insulation material requires on-site work, which increases the number of work days and is relatively costly. . Furthermore, simply wrapping a heat insulating material around the pipe does not provide a sufficient heat retaining effect, and there are cases where it is not possible to maintain the fluid in the pipe within a desired temperature range.

"Problem B to be solved by the invention J The present invention has been made in view of the above problems,
It is an object of the present invention to provide a heat-retaining pipe that can be produced in a factory and whose degree of heat retention can be adjusted, and to provide a method for manufacturing the heat-retaining pipe.

"Means and Effects for Solving the Problems" According to the present invention, in a heat-retaining pipe for keeping a fluid flowing in a pipeline warm, on the outer periphery of a straight or bent pipe, A heat-retaining pipe is provided, which is formed to follow the outer shape of the pipe and is characterized in that an electric heating sheet having heating wires sandwiched between thermosetting welded rubber sheets is tightly bonded.

According to the above configuration, the value of the current flowing through the heating wire is adjusted,
Alternatively, the degree of heat retention can be adjusted by adjusting the on/off time of the current. Furthermore, since the rubber sheet that holds the heating wires is both an electrical insulator and a heat insulator, the amount of heat radiated from the pipe is minimized.

Further, the manufacturing method of the present invention includes a wiring step of planting positioning pins in a mold made of a plywood board having a large number of pin holes, and wiring heating wires to the positioning pins; a bonding transfer step in which a first thermosetting welding rubber sheet is placed on the mold, and the heating wire is bonded and transferred to the first thermosetting welding rubber sheet by heating under pressure between the mold and a hot plate; A second thermosetting welding rubber sheet is layered on top of the first thermosetting welding rubber sheet onto which the heat rays have been transferred, and the second thermosetting welding rubber sheet is heated under pressure to form an electric heating sheet, and the second thermosetting welding rubber sheet is preformed by the above-mentioned sandwiching and adhesion step. The wrapping process involves wrapping an electric heating sheet around a straight or bent pipe and applying a binder between the T4 heating sheet and the pipe. It is characterized by performing a bonding molding process in which heat is applied while applying pressure with synthetic rubber in a sealed mold.

According to the above configuration, the plywood board has a length of 18 mm in standard dimensions.
Because it has a huge size of 0e+* and 90em in width,
By using this plywood board, a gigantic mold can be easily obtained, and if necessary, an even gigantic mold can be manufactured easily and at a relatively low cost by joining several plywood boards of standard dimensions. In addition, since plywood is made of several thin sheets stacked and glued together so that they are perpendicular to each other, the positioning pins are held in place by applying appropriate squeaks to the mold, and when force is applied, they can be inserted into the mold. The sinker stays in the mold without falling. A thermosetting welding rubber sheet, such as a silicone rubber sheet, is well welded to a heating wire during preforming, and is heated and cured in a bonding process to be molded into a desired shape and tightly adhered to a pipe.

"Example" Hereinafter, an example of the present invention will be specifically described with reference to the drawings.

In FIGS. 1(a), (b), 2(a), (b), and 3, mold 1 is made by joining two plywood boards 2.3 with flat metal fittings 4 and wood screws 5. In this example, the length is about 360 cm, the width W is about 90 am, and the thickness D is about 0.9 cm. A large number of pin holes IA are bored in the mold 1, and positioning pins 6 are inserted into each of the pin holes IA. As shown in Fig. 3, the plywood board 2.3 in type 1 is made up of a large number of thin plates 7, 8, 9, 10... stacked and glued together orthogonally to each other.
A thin piece of wood protrudes from the pin hole 1A drilled in the plywood board 2.3, and the positioning pin 6 is easily held in the pin hole IA by the piece of wood, and becomes freely movable when force is applied from the axial direction.

Figure 4 (a), (b), (c), (d>, (e) shows the preforming method. In the wiring process shown in Figure 4 (a), the positioning pin inserted into the mold 1 The heating wire 20 is hooked and/or wrapped around the wire 6 for wiring.

In the bonding transfer process shown in FIG. 4(b), the raw silicone rubber sheet 21 reinforced with glass cloth is
When placed on the top and pressurized and heated by a heat press (not shown), the positioning pin 6 sinks below the mold 1, and the heating wires 20 on the mold 1 form a thermosetting welding rubber sheet while remaining in the wired shape. It is bonded and transferred to the silicon raw rubber sheet 21. Subsequently, in the sandwiching and bonding process shown in FIG.
is turned over, another silicone raw rubber sheet 22 is placed on top of this sheet 21, and when the sheet 21 and the sheet 22 are pressed and heated by a hot press, the sheets 21 and 22 are bonded to each other with the heating wire 20 sandwiched therebetween. In the terminal connection step shown in FIG. 4(d), a soft lead wire 24 such as a Teflon electric wire made by twisting a large number of wires is connected to the end of the heating wire 20 via the terminal plate 23. Finally, in the terminal protection step shown in FIG. 4(e), a piece of silicone raw rubber sheet 25 is placed on the terminal board 23 and heated under pressure using a heat press to form a preformed flat surface. An electric heating sheet 26 having a shape can be manufactured. Note that the electric heating sheet 26 manufactured according to this example has a vertical 300C ring,
It was the size of a 40cm wheel.

Mold for performing the bonding molding process jf! A dish-shaped intermediate mold 32 is fitted into a six-box-shaped lower mold 31 shown in FIG. 5, and a plug-shaped upper mold 33 is fitted into the intermediate mold 32. Flow holes 32a are formed in the lower part of the intermediate mold 32. At the beginning of the bonding and molding process, the synthetic rubber 34 is filled between the intermediate mold 32 and the upper mold 33.
In No. 4, inferior materials are used because they are discarded after the bonding and molding process is completed. Inside the lower mold 31 is a straight pipe 35 as shown in FIG. 6(a). A 90° bent pipe 36 as shown in FIG. 6(b). or Figure 6 (C
45° bent pipes 37 as shown in ) are arranged, and core metals 38 are passed through these pipes 35, 36, 37. The core metal 38 is for preventing the pipes 35 to 37 from being crushed by high molding pressure. The pipes 35 to 37 are coated with an adhesive or a primer, and are wrapped with a preformed electric heating sheet 26.

In the above configuration, the intermediate mold 32 is first filled with synthetic rubber 34, and when the upper mold 33 and the lower mold 31 are pressed from below by a hot plate of a heat press (not shown), the synthetic rubber 34 is filled into the upper mold 33. The liquid is pressurized between the mold 32 and the intermediate mold 32, and gradually flows through the flow holes 32a, filling the lower mold 31. Then, the entire circumference of the electric heating sheet 26 in the lower die 31 is pressed evenly and strongly toward the pipes 35 to 37 by the synthetic rubber 34, and is heated and cured by the hot plate.
The electric heating sheet 26 is molded into a good pipe shape without streaks along the surface shape of the pipes 35 to 37, and at the same time is tightly adhered and strongly adhered to the pipes 35 to 37, thereby producing a heat retaining pipe 40. be able to. Note that the synthetic rubber 34 is peeled off from the electric heating sheet 26 after being pressurized and heated and discarded.

Note that if the diameters, lengths, etc. of the pipes 35 to 37 are standardized, the heat retaining pipe 40 becomes more suitable for factory production.

"Effects" As described above, the heat-retaining pipe of the present invention is formed around the outer circumference of a straight or bent pipe so as to follow the outer shape of the pipe, and a heating wire is inserted between thermosetting welded rubber sheets. Since it is made by tightly bonding sandwiched electric heating sheets, the degree of heat retention can be freely adjusted as desired by the heat generated by the heating wire, and the number of days of on-site work can be reduced by producing it in advance at the factory. This has the excellent effect of easily providing a homogeneous heat-retaining pipe.

Further, since the manufacturing method of the present invention uses a mold made of plywood, it is possible to manufacture an electric heating sheet of a gigantic size suitable for a heat-retaining pipe at a relatively low cost and in good condition.
There are excellent effects such as being able to quickly and easily respond to changes in the dimensions of the electrothermal sheet to be manufactured.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are a plan view and a front view showing a mold used in an embodiment of the present invention, and FIGS. 2(a) and (b) are cross-sectional views showing the bonding structure of plywood boards constituting the mold. and bottom view,
Figure 3 is a cross-sectional view showing the positioning pin inserted into the mold, Figures 4 (a) to (e) are perspective views showing the preforming method, and Figure 5 is a mold for performing the bonding molding process. A cross-sectional diagram showing the structure, Fig. 6(a). (b) and (c) are front views showing manufactured heat-retaining pipes. 190. Type, 2,3. ,,veneer, 61.1 positioning pin, 20,,,electric f! ! , line, 21, 22.
, silicone raw rubber sheet, 26 , heat sheet, 31 , lower mold, 32 , middle mold, 33
,,,upper mold, 34,,,synthetic rubber, 35. ,,rI
￥Tubular pipe, 36,... 90° bend pipe,
37,... 45° bent pipe, 38, core metal, 40, heat insulation pipe. Figure 2 (a) (b) Figure 3 Figure 5 Figure 26 3b (Jb, J-/) Figure 6

Claims (2)

[Claims] (1) In a heat-retaining pipe for keeping fluid flowing in a pipeline warm, a thermosetting welding rubber sheet is formed around the outer periphery of a straight or bent pipe to follow the outer shape of the pipe. A heat-retaining pipe characterized by tightly bonding electric heating sheets with heating wires sandwiched between them. (2) A wiring process in which positioning pins are planted in a mold made of a plywood board with a large number of pin holes, and heating wires are wired to the positioning pins, and a first thermosetting process is performed on the wired heating wires. a bonding transfer step in which a thermosetting welding rubber sheet is arranged and heated under pressure between the mold and a hot plate to bond and transfer the heating wire to the first thermosetting welding rubber sheet; A clamping and bonding step in which a second thermosetting welding rubber sheet is layered on top of the first thermosetting welding rubber sheet and heating under pressure to form an electric heating sheet; and the electric heating sheet preformed by the clamping and bonding step is then heated into a straight tube shape. Alternatively, there is a wrapping process in which the electric heating sheet is wrapped around a bent pipe and a binder is applied between the electric heating sheet and the pipe, and a core metal is passed through the pipe around which the electric heating sheet is wrapped, and the metal is placed in a sealed mold. 1. A method for manufacturing a heat-retaining pipe, characterized by performing a bonding molding step of heating while pressurizing with synthetic rubber.