CN201114838Y - Improved compound rubber heating cable - Google Patents

Abstract

The utility model relates to a cable, in particular to a heating cable made from modified synthetic rubber, which is characterized in that the heating cable consists of a core of conductor (1), a high temperature resistant mylar (2), an insulating layer (3), a tensile isolated layer (4), a shielding layer (5) and a restrictive coating (6). The core of conductor (1) is wrapped in the high temperature resistant mylar (2); the insulating layer (3) is wrapped above the high temperature resistant mylar (2); the insulating layer (3) is wrapped below the tensile isolated layer (4); the shielding layer (5) is wrapped above the tensile isolated layer (4); the restrictive coating (6) is wrapped on the outermost layer of the shielding layer (5). The heating cable of the utility mode has the advantages of simple structure and low cost, and effectively solves the problem that aging and pastiness are accelerated by oxidation and insulation of a core of heating cable; in addition, the heating cable also enhances tensile strength of a heating cable; the isolation also prevents chemical reaction between vulcanizing agent in the insulating and sheathing materials and partially woven and shielded copper wire. The heating cable made from modified synthetic rubber adopts copper-coated iron wire to replace brass wires, thus thoroughly solving the problem of electromagnetic radiation.

Description

Modification synthetic rubber heating cable

Technical field:

The utility model relates to cable, is specially a modification synthetic rubber heating cable.

Background technology:

(written historical materials both domestic and external has different titles to heating cable, as Geothermal electric cable, heating cable, hereinafter to be referred as hot cable.) originate from Northern Europe decades ago, be popular in states such as American-European continent, Japan and Korea S..Pass to China the time in several years only.Because this ground radiation heating mode based on hot cable, energy-saving and environmental protection, health, comfortable, cost, useful life aspects all be better than traditional hot water circuit heating system, also be better than canopy face, metope heating systems such as Electric radiant Heating Film, electric heater, radiant panel, so be widely adopted in China, in the ascendant.

In the surface water mud layer, belong to disguised heating facility because hot cable is laid in, therefore require to grow its useful life, should be with the same longevity of building (50-70).The structure of hot cable mainly is made up of core, insulation, shielding and sheath four parts.Core rational in infrastructurely can ensure useful life as long as selection is proper.What influence hot useful life mainly is insulation and sheath (also claiming sheath).And the serviceability temperature of material and mechanical strength are the key factors in decision insulation and sheath useful life.

Produce in the process of hot cable in research and development, once collected external import and homemade various hot cable sample, the chemical examination discriminating has been carried out in insulation and sheath material.Find that the overwhelming majority is external, the insulation of domestic hot cable crosslinked polyethylene (PE-X or XLPE), sheath polyvinyl chloride (PVC) or PE-X.Belong to the plastics class.And the hot cable of only a few foreign country import insulate with ethylene propylene monomer (EPR), acrylonitrile-butadiene rubber sulfide polymers such as (NBR), and sheath belongs to synthetic rubber with chlorosulfonated polyethylene (CSP).Above-mentioned material uses (work) temperature 80-90 ℃, and the linear heat generation rate of making hot cable is generally 20 watts of every linear meters (20W/m), is 2520W/m to the maximum.Because heat resistance is poor, PE-X, PVC plastics (or synthetic rubber) material use in hot cable that there are the following problems influences useful life:

1, do not reach the requirement in useful life under the normal working temperature.

Use above-mentioned (work) temperature is a rated value, must limit the material working temperature in order to guarantee useful life.With same be raw material with crosslinked polyethylene, the heat supply water pipe of imbedding equally in the surface water mud layer (can be considered the PE-X material) is example, and the relation in working temperature and useful life is described.Referring to National Standard ground radiation heating technical stipulation " 38, B.1.2-1, table (draws from " hot and cold water crosslinked polyethylene PE-X pipe-line system " GB/T18992.2) plastic tube service condition rank 4: 60 ℃ of working temperatures, 25 years time, 70 ℃ of maximum operating temperatures, 2.5 years time, 100 ℃ of fault temperature, 100 hours time.Certainly, the time here is in order to ensure that in the operating time that limits at each temperature, be not useful life in useful life.But can see that overtemperature is quantitative value and the time shortens into multiple, also reflects temperature and life relation.With the residence heating is example, according to National Standard ground radiation heating technical regulation " under the heating thermal capacity and routine (technology) way environment of design, the hot cable of 20W/m of installation is carried out temperature survey.The core of hot cable (insulation) working temperature changes in 60 ℃ of-80 ℃ of scopes from low to high with the ambient temperature of heating, 70 ℃ of average working temperatures, 80 ℃ of maximum operating temperatures.Contrast service condition rank is as can be seen: the average working temperature of hot cable has surpassed the working temperature of material, and near maximum operating temperature, and the actual maximum operating temperature of hot cable surpasses 10 ℃ of the maximum operating temperatures of material.This shows the long-term overtemperature operating state of hot cable, be difficult to the useful life that guarantees that 50 years (is 25 years by the heating phase) is above.

2, under the fault temperature, the overheated ability of hot cable is very easily damaged.

Hot cable is in service in energising, and state can break down.As 1) electric power system overvoltage, disconnected zero line etc., the power output of hot cable is increased; 2) there is adiabatic covering on local ground, influences the heat conduction of hot cable; 3) ground cement preserving period (28 days) does not arrive, and hot cable heats in advance.Steam in the cement makes the portion of hot cable separate with cement layer, the middle heat insulation gas-bearing formation (or crack) that forms, and the result can make hot cable temperature rise, and surpasses 100 ℃ of the fault temperature of material.Malfunction, especially the 3rd) the hidden defective fault of kind is difficult for finding, can't handles early, long-term existence that aging acceleration of insulation, sheath that causes hot cable caused hot cable damage within a short period of time (several months or several days).This is the hot cable example that repeatedly takes place in service.

3, plastic hot cable resistance to low temperature is poor, and outdoor application is fragile.

Plastic materials such as crosslinked polyethylene, polyvinyl chloride is at embrittlement below 0 ℃, and the low more fragility of temperature is big more, brittle without solidity.Be used for road, bridge, airfield runway snow melting as hot cable.Temperature is below-20 ℃, and the strong row vibrations that produce because of vehicle, aircraft etc. are insulated and sheath generation embrittlement easily, have destroyed sealing, have also damaged hot cable.

4, hot cable is the same with the common wiring cable, is applied in various environment and place that the different service conditions of indoor and outdoor require.For example: the heat insulation function of hot cable can be applied in jar, the pipe insulation in oil gas field, chemical plant, requires to have good oil resistant or solvent resistance.Hot cable is also had different performance requirements such as heat-proof aging, radiation hardness, anti-ozone, anti-corona, weather in different applications, and the requirement of different linear heat generation rate (unit container W/m).Obviously the plastic hot cable can not satisfy these requirements fully.(1) the modification synthetic rubber is the same with synthetic rubber all becomes rubber by sulfuration, has the Sulfur person of one-tenth peroxide in the vulcanizing agent equally.Hot cable core is the alloy of several metals, and copper removal also contains iron and violent outward.Hot cable is different with the common wiring cable is that its working temperature is higher, and the effect of heat is bigger, causes oxidation, and aging reaction speed is faster, and the oxide layer of core is constantly thickeied, and the resistance of hot cable is constantly increased, thermal power (P=V ²/ R) constantly grand down.The aging speed of insulation is accelerated, and impels the life-span of hot cable shorter and shorter.With the quality of hot cable and the requirement in life-span are run in the opposite direction, the pad cable is that the resistance work done by core is sent out and thought the hot cable rice resistance (R/m of all size ²) be certain, core zinc-plated directly influence rice resistance and linear heat generation rate.So can not deal with problems with zinc-plated method.(2) electromagnetic radiation (pollution) can be brought out some diseases, especially endangers seriously for children, and hot cable is laid under the ground surface and people's close contact, and its electromagnetic radiation causes concern.Copper cash is knitted shielding partially can only eliminate induced electricity, and can not eliminate magnetic.

Summary of the invention:

The purpose of this utility model is to provide a kind of simple in structure, with low cost, high temperature resistant, tensile strength of increasing hot cable, prevent to insulate and sheath material in vulcanizing agent and the modification synthetic rubber heating cable of knitting the copper cash generation chemical reaction of shielding partially.The purpose of this utility model is achieved in that it is made up of core, high temperature resistance polyester film, insulating barrier, tension separator, screen, restrictive coating.Be wrapped in core in the high temperature resistance polyester film, high temperature resistance polyester film top is wrapped in insulating barrier, is wrapped in insulating barrier under the tension separator, tension separator top is wrapped in screen, is wrapped in restrictive coating on the screen outermost layer.The utility model has the advantages that: simple in structure, with low cost, effectively solved hot cable core oxidation, the insulation accelerated aging problem that is clamminess.Increase the tensile strength of hot cable, the 2nd, isolate prevent to insulate and sheath material in vulcanizing agent and the copper cash generation chemical reaction of knitting shielding partially.The hot cable of modification synthetic rubber adopts the copper-clad iron wire to replace copper wire thoroughly to solve electromagnetic radiation.

Description of drawings:

Fig. 1 is the utility model structural principle generalized section.

Embodiment:

Be wrapped in core 1 in high temperature resistance polyester film 2, high temperature resistance polyester film 2 tops are wrapped in insulating barrier 3, and the tension separator is wrapped in insulating barrier 3 for 4 times, tension separator 4 tops are wrapped in screen 5, are wrapped in restrictive coating 6 on screen 5 outermost layers.The high temperature resistance polyester film is high temperature resistant PEN film, 270 ℃ of softening temperatures, 160 ℃ of long-term serviceability temperatures;

Insulating barrier is modification silastic elastomer or modification ethylene-propylene rubber, and insulation should extrude closely, and thickness is even, and color and luster is even, free from admixture, and the visible bubble of no eyesight, sand holes defective are peeled off from conductor on the insulation cross section; B, technical parameter: insulation thickness mean value is 1.0mm, and more than the thinnest dot thickness 〉=0.8mm, the spark-over test voltage is 6KV;

The tension separator is that polybutylene terephthalate (PBT) is sneaked into 10% pet film, and tensile strength is up to 4000MPa;

Screen is a, tinning steel-in-copper, iron wire silk, and 32 braidings form; B, shielding with the copper covered steel wire surface should be bright and clean, defective that oxidation, spot, slight crack, scuffing must not be arranged, c, tin coating answer smooth and continuous that any defective that does not conform to good product must not be arranged, d, weaving the back braid should be closely, even, tangible thread cast-off can not be arranged, run defectives such as line, broken string, and there is not the hole scar, oxidative phenomena, e, braid technical parameter: cable size: 2.9mm, braiding back cable size: 3.7mm, cable pitch: 35mm, every ingot monofilament radical before tinning steel-in-copper linear diameter: 0.2mm, the braiding: 2, number of share of stock: 32;

Restrictive coating is modification ethylene-propylene rubber or modified butadiene acrylonitrile rubber, requires sulfuration good, extrudes closely, and thickness is even, surfacing, and free from admixture, the visible bubble of no eyesight, sand holes defective on the material cross section extrude and should be strictly on guard against the termination water inlet and the appearance of coming unstuck in the process,

The utility model adopts the existing type structure of the hot cable of change, core and insulating barrier isolated.With a kind of not with the high temperature resistance polyester film of vulcanizing agent generation chemical reaction, wrap in the outer structure of core, effectively solved hot cable core oxidation, an insulation accelerated aging difficult problem that is clamminess.In addition, respectively at hot cable screen and insulating barrier, add the resistant to elevated temperatures tension separator of one deck between restrictive coating, the tensile strength, the isolation that increase hot cable prevent the vulcanizing agent in insulating barrier and the restrictive coating material and knit the copper cash generation chemical reaction of shielding partially.Copper wire is knitted screen partially can only eliminate induced electricity, and can not eliminate magnetic.For this reason, the utility model adopts the copper-clad iron wire to replace copper wire thoroughly to solve this problem as screen.

Claims (1)

1. a modification synthetic rubber heating cable, it is made up of core (1), high temperature resistance polyester film (2), insulating barrier (3), tension separator (4), screen (5), restrictive coating (6), it is characterized in that: in high temperature resistance polyester film (2), be wrapped in core (1), high temperature resistance polyester film (2) top is wrapped in insulating barrier (3), be wrapped in screen (5) above being wrapped in insulating barrier (3), tension separator (4) under the tension separator (4), be wrapped in restrictive coating (6) on screen (5) outermost layer.

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