JPH02292594A - Resin heater pipe - Google Patents

Abstract

PURPOSE:To improve waterproof and acidproof properties by interposing a semi-conductive layer of polyolefine system resin, which contains carbon black and providing electrode conductors between inner and outer pipes of polyolefine system resin. CONSTITUTION:A semi-conductive layer 3, in which conductive carbon black is compounded with polyolefine system resin, is provided between inner and outer pipes 1 and 2 formed by polyolefine system resin. At least a pair of electrodes 4 are provided in the inside of the semiconductive layer 3. Further the electrodes 4 may be located in an external or internal surface of the semiconductive layer 3. As a result, an integral unit between the layers can be easily obtained, further a resin heater pipe, which is excellent in waterproof acidproof, alkaliproof, properties etc., is obtained.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applicable to pipes used for water supply and drainage in homes and factories, or pipes used as passages for liquids and gases in factories, and The present invention relates to a resin heater tube useful as a tube for protecting and heating metal tubes used as passages for liquids and gases.

BACKGROUND ART Conventionally, resin pipes have been known as pipes used for water supply and drainage, but when heating was required, another heating means was provided around the resin pipe.

In addition, the use of resin pipes used as passages for liquids and gases in factories is still unexplored, and metal pipes have mainly been used, and foamed resin tape is used to keep them warm. They used to heat it by wrapping it or wrapping it with heater tape. <Problems to be Solved by the Invention> Providing a separate heating or heat retention means as described above is not only troublesome, but also requires a lot of work and is inefficient to set up a facility to control heating to a constant temperature. bad. <Means for Solving the Problems> The present invention aims to solve the above-mentioned problems, and the outline thereof is as follows.

The tube made of polyolefin resin has a double structure consisting of an inner tube and an outer tube, and a semiconductive resin tube made of polyolefin resin containing carbon black is interposed between the two, and this semiconductive This resin heater tube is characterized in that one or more pairs of electrode conductors are provided on the inner surface, outer surface, or wall thickness of the resin tube.

As a result of the above structure, a polyolefin resin with good chemical resistance and processability is used, so a wider range of liquids and gases can be passed through the pipe than with metals. In addition, a metal tube can be installed separately inside, and heating is performed by a semiconductive resin tube installed in the middle of the resin tube, so it can be heated with a uniform temperature distribution. Since it is made of the same type of material, it has good adhesion between the eyebrows, and it is also possible to manufacture it by simultaneously extruding three layers while inserting wire rods to serve as electrodes at predetermined positions as the case may be.

Furthermore, each layer of the present invention can be made separately or as a single layer, and can be made to have heat shrinkability. It can be applied well.

Embodiment> As shown in FIG. 1, an embodiment of the present invention is a method in which conductive carbon black is blended into a polyolefin resin between an inner tube ■ made of a polyolefin resin and an outer tube 2 made of the same resin. A semiconductive layer 3 is provided. For example, at least one pair of electrodes 4 is provided inside this semiconducting layer 3, whereby the semiconducting layer 3 generates heat and can heat the inside. Although the case where the electrode is provided inside or outside the semiconducting layer 3 is not shown, it will be easily understood.

In addition, the resin heater tube of the present invention can be manufactured not only by extrusion method but also by tape winding method by heating and fusing the wound layers together, so that it can be manufactured in various lengths and outer diameters. You can easily offer different things.

<Effects of the Invention> The effects of the present invention are to provide a resin heater tube that is made entirely of polyolefin, can easily have an integral glabella, and has excellent water resistance, acid resistance, alkali resistance, etc. be able to.

Especially when passing a fluid that tends to freeze at low temperatures, such as in winter, it is easy to prevent freezing by heating the heater.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention. l: inner tube, 2: outer tube, 3: semiconductive resin tube 4: electrode conductor

Claims (1)

[Claims] A semiconductive resin tube made of a polyolefin resin containing carbon black is interposed between an inner tube made of a polyolefin resin and an outer tube, and a semiconductive resin tube made of a polyolefin resin containing carbon black is interposed between the inner tube, the outer surface, or the wall thickness of the semiconductive resin tube. A resin heater tube characterized in that it is provided with one or more pairs of electrode conductors.