JPS60211191A - Long-sized heat-insulating material for piping - 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 Application of the Invention] The present invention relates to a heat insulating material for preventing freezing and condensation of various piping systems in nuclear power plants and the like.

[Background of the invention]

Conventionally, measures to prevent pipes from freezing have been taken using a combination of electric heaters and heat insulating materials.

The prior art is shown in FIG. 1 and FIGS. 2(a) and 2(b).

An electric heater 1 (hereinafter referred to as a heating cable) is wound around the target pipe 5, and a heat insulating material 2 such as urethane foam and an exterior material 3 such as an aluminum plate are wound thereon.

Normally, anti-freeze construction is carried out after piping installation is completed, but
The following problems have arisen during construction: As shown in Figures 1 and 2 (aXb), the heating cables are wrapped around the knob 7 and flange 6 in an overlapping manner, resulting in poor workability. Therefore, disassembly and inspection after construction is inconvenient.

(2) If the shape of the flange 6 or the like is not simple, the heating cable 1 is wrapped around it, and then the paste-like heat insulating material 2' is attached manually according to the shape of the actual product, resulting in poor workability.

(3) Since the exterior material 3 is attached after the heat insulating material 2' has hardened, skilled work is required to assemble the exterior material 3 on site.

(4) It is difficult to work in nuclear power plants, etc. because the piping is complicated and curved and the working environment is narrow.

(5) The absolute amount of piping to be protected against freezing is large, and most of the piping runs at a level higher than the floor, so the working conditions are poor and installation cannot be done easily.

The use of conventional heating cables as heating bodies also has the following drawbacks.

(6) '! It takes time to calculate the required resistance value of the air heater.

Since the specifications of commercially available heaters are graded, trouble may occur in selection.

(7) It is desirable that the surface to be heated be heated uniformly, but since the heater is a linear heating source, there is a risk of partial heating.

Particularly in the case of a heated object such as pulp or a flange that has an annular shape and is not simple, overlapping winding (overheating) or rough winding (low temperature) of the heater tends to occur.

(8) When using a sheathed heater as a heating cable, the processing of the connection terminal is special and requires skill. Furthermore, even when a cable type heater is used, since the connection work is not a simple full group type, there is a possibility that erroneous or incomplete connections may occur.

(9) A gap equal to the thickness of the heater is created between the heat insulating material and the piping, and the outer diameter of the heat insulating material becomes smaller by the thickness of the heater. Therefore, as the outer diameter increases, the amount of heat dissipated increases and heat loss increases.

As described above, traditional pipe heating techniques for the purpose of preventing freezing or condensation have inherent drawbacks.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an antifreeze device which simplifies the design procedure to eliminate the drawbacks of the prior art, has good thermal efficiency, and is easy to work with.

[G chivalry of invention]

The elongated heat insulating material for piping of the present invention is characterized in that it sequentially includes an insulating layer having adhesiveness and adhesive properties, a heating element layer in which electrode lead wires are embedded, and a heat insulating material layer.

In this way, the above objective is achieved by providing the required anti-freezing effect with a standard long heat insulating material for piping.

[Embodiments of the invention]

Examples are shown in FIGS. 3-11.

FIG. 3(a) shows a module that integrates a heater for plane heating and heat retention, and FIG. 3(b) is a developed view.

The module includes a heating element 11. It consists of a self-adhesive soft insulator 9 that insulates the heating element and the surface to be heated, a heat insulator 2, and an exterior material 3, which are glued together to form a single body as shown in the upper diagram of Fig. 3, so that the structure can be easily understood. In the upper figure of Figure 3, the size of each component is shown different, and in both the upper and lower figures of Figure 3, the electrode lead wire 10 to the heating element 11 is shown pulled out to the outside of the heating element. It is.

FIG. 4 shows the structure of the heating element 11.

The heating element 11 is a semiconductor made by mixing a synthetic resin 13 with conductive powder such as carbon powder 14, and has a structure in which a pair of electrode lead wires 10 are embedded. As shown in FIG. 4, this is an elongated flat plate with a width a, a thickness S, and a length C.

When a voltage is applied to the pair of electrode lead wires 10, a current 12 flows in the heating element 11 sandwiched between the electrode lead wires 10, and the entire flat heating element generates heat.

When the temperature of the heating element 11 increases due to heat generation, the resistance increases and the current 12 decreases as described above.

Therefore, the heat generated from the heating element is reduced, and as a result, a temperature-heat generation (ie, heat output) ratio as illustrated in FIG. 5 is obtained. Further, in FIG. 4, by appropriately selecting the width a, thickness b and applied voltage of the heating element 11, heating elements having various shapes and heat outputs can be obtained.

In the heater and heat-retaining trace according to the present invention, the necessary properties such as heat generation performance, heat-retaining function, and external damage protection function are maintained regardless of the length C, so it can be cut to any length. be.

Above, examples have been shown for the case of flat heating, but when used for curved surfaces such as piping or valves,
Made of rubber/easy to pull.

An example will be shown below in which it is applicable to curved surfaces such as piping or valves.

FIG. 6 shows a state in which a heating heater and a heat-retaining trace are wrapped around the piping. (The four components are the same as the module that integrates the flat heating element and heat insulation shown in Figure 3.

As shown in Fig. 6, in order to eliminate the gap between the pipe and the strip trace, the insulator 9 is made of a self-adhesive soft insulator.
It is made wider than the heating element 11, the heat insulating body 2, and the exterior material 3. In this case, the self-adhesive soft insulators are wrapped around each other and are integrated and tightly adhered to each other, so thermal efficiency is improved. Furthermore, the exterior material 3 is made of a flexible caliper tube or the like, and has a wound protection function and adhesion.

FIG. 7 shows an example in which piping and pulp are assembled. Even valves, flanges, etc. that are annular in shape and not simple can be wrapped in layers.

As described above, by integrating the strip trace, it is possible to prevent freezing and condensation of the piping system.

〔Effect of the invention〕

(1) There is no need to calculate resistance, and the heating element can be selected directly from the temperature and heat output characteristics of the heating element. Therefore, the design time can be shortened, and the possibility of design errors can be reduced.

(2) Since it is a planar heating element, heating is uniform and the heating element is in close contact with the surface to be heated, so thermal efficiency is improved.

(3) By using an integrated long heat insulating material for piping, there is no need to sequentially attach the heating element, heat insulating body, and exterior body, and the working time is shortened.

(4) P1 workability is improved by making it into an integrated band-like trace and reducing the manual work required for on-site adjustment.

[Brief explanation of drawings]

FIG. 1 shows a freeze prevention structure of a flange portion according to the prior art, and FIG. 2 shows a freeze prevention structure of a valve portion according to the prior art. 3 to 7 show embodiments of the present invention, and FIG. 3 shows a heater for flat heating. A perspective view of the heat insulation module, Fig. 4 is a structural diagram of the heating element, Fig. 5 is a graph of the temperature-heat generation characteristic of the heating element, and Fig. 6 is:
FIG. 7, which is a perspective view of the elongated heat insulating material for piping when wrapped around the piping, is a structural diagram when the piping and the valve are combined. 1... Heating cable, 2... Heat insulation material, 2'
... Valve insulation material, 3, 4... Exterior material, 5...
Piping, 6... Flange, 7... Pulp, 8... Exterior band, 9... Insulator, 10... Electrode lead wire, 11... Heating element, 12... Current, 13...Synthetic resin or synthetic rubber, 14...Carbon powder. Agent Patent Attorney Akio Takahashi 2 (Kyu) (b) No. 32

Claims (1)

[Claims] 1. A composition comprising (a) an insulating material layer and (b) embedded electrode lead wires. 2. Claim 1, characterized in that the insulating material layer has adhesive or adhesive properties. Long insulation material for piping. 3. The elongated heat insulating material for piping according to claim 1, wherein the heating element made of synthetic resin or synthetic rubber is a foam. 4. A long heat insulating material for piping, characterized in that it has a structure that sequentially includes (a) an insulating material layer, 6) a synthetic resin or synthetic rubber heating element in which an electrode lead wire is embedded, and (C) a heat insulating material layer. 5. The elongated heat insulating material for piping according to claim 4, wherein the insulating material layer is an adhesive layer or an adhesive layer. 6. Claim 4 or 5, characterized in that the insulating material layer is an insulating film coated with an adhesive or an adhesive.
Long insulation material for piping as described in section.