CN202134273U - A flame retardant and high temperature resistant intrinsically safe computer cable - Google Patents

Abstract

The utility model discloses a flame-retardant high temperature-resistant intrinsically safe computer cable, comprising a plurality of conductor groups and insulating layers, wherein each of the plurality of conductor groups is formed by pairedly twisting two conductors each wrapped with the insulating layer, the outer wall of each of the plurality of conductor groups is attached with a color band, the outside of the plurality of conductor groups and the color band is wrapped with an inner lapped covering, the outside of the inner lapped covering is wrapped with a sub-shielding layer, a plurality of glass fiber ropes are parallelly arranged in gaps between the plurality of conductor groups each wrapped with the sub-shielding layer, then the plurality of conductor groups and the plurality of glass fiber ropes are twisted into a bundle again, the outside of the sub-shielding layer and the plurality of glass fiber ropes is wrapped with an outer lapping cover after the bundle is formed, which is formed by binding a layer of water blocking tape between two layers of alkali-free glass fiber tapes, and the outside of the outer lapping covering is sequentially wrapped with a primary shielding layer and a sheath layer. The flame-retardant high temperature-resistant intrinsically safe computer cable has a twisted structure of pairedly twisted conductor groups and glass fiber ropes, and the outer lapping covering of the cable is formed by bonding two layers of alkali-free glass fiber tapes with a layer of water blocking tape, therefore the compactness and the water blocking performance of the structure of the cable are improved.

Description

A flame retardant and high temperature resistant intrinsically safe computer cable

Technical field:

The utility model relates to an instrument cable, in particular to a flame-retardant and high-temperature-resistant intrinsically safe computer cable.

Background technique:

In petrochemical, mining, gas engineering and other places with explosive hazards, the requirements for "explosion-proof" are usually put forward for cables. Since electric sparks and thermal effects are the main causes of explosive gas explosions, and from the perspective of system wiring, since cables are composed of many distributed components such as distributed capacitances and inductances, they become energy storage components accordingly, so in signal transmission A certain amount of energy is inevitably stored in the process. Once the system fails, the stored energy will be released in the form of electric sparks or thermal effects, affecting the safety of the system. Therefore, the cable is required to have low capacitance and low inductance, the cable itself has less charge, and it is not easy to generate electric sparks; secondly, the cable is required to have good shielding performance, excellent resistance to external electromagnetic field interference and no external interference. This requires the cables to be "intrinsically safe".

The original structure of this type of cable is not compact enough, the waterproof performance is poor, and the intrinsic safety characteristic cannot meet the actual work requirements.

Utility model content:

The purpose of this utility model is to provide a flame-retardant and high-temperature-resistant intrinsically safe computer cable, which solves the problems of insufficient compact structure, poor water-blocking performance, explosive gas explosion caused by electric sparks and thermal effects, and the cable's own capacitance and distributed inductance.

The technical scheme of the present utility model is as follows:

Flame-retardant and high-temperature-resistant intrinsically safe computer cable, including several conductor groups and insulating layers, is characterized in that: several conductor groups are composed of two twisted conductors wrapped with insulating layers, and several conductor groups are attached with ribbons on the outer wall , several conductor groups and ribbons are wrapped with an inner wrapping layer, the inner wrapping layer is made of one or several layers of polyester tape wrapping, the inner wrapping layer is wrapped with a sub-shielding layer, and the number of wrapping sub-shielding layers Several glass fiber ropes are placed side by side in the gap between two conductor groups and then twisted into bundles again. After the bundles are bundled, the shielding layer and the outside of several glass fiber ropes are wrapped with an outer tape layer. The outer tape layer is made of two layers of alkali-free glass fiber tape. A layer of water-blocking tape is bonded between them, and the outside of the outer tape layer is wrapped with a total shielding layer and a sheath layer in turn.

The flame-retardant and high-temperature-resistant intrinsically safe computer cable is characterized in that: the sub-shielding layer and the overall shielding layer are provided with drain wires, the drain wire is made of a copper wire, and the cross-section of the drain wire is not less than 0.3mm ² .

The flame-retardant and high-temperature-resistant intrinsically safe computer cable is characterized in that the materials of the insulating layer and the sheath layer are fluoroplastics.

The selected material of the utility model is:

(1) Conductor. Intrinsically safe system instrument cables are used to transmit current signals controlled and simulated by weak current systems. Due to the transmission of large current signals, the cross-section of the conductor is larger than that of the communication cable, which is generally the same as that of the ordinary control cable. The more commonly used conductor cross-sections are 0.75, 1.0, 1.5, 2.5mm ² . According to the requirements of different service conditions, the conductor structure can choose the first, second or fifth structure that meets the requirements of the standard GB/T3956.

(2) Insulation. The insulating material used for instrument cables is fluorine plastic. It improves the mechanical strength of the cable and increases the working temperature of the cable to 200°C. It has excellent electrical properties, low dielectric constant, high thermal stability, low flammability, low moisture absorption, and excellent weather resistance.

(3) Twisted pair. Since the signal transmitted by the instrument cable is the same as the communication cable, which is a weak high-frequency signal, the insulated core structure of the instrument cable adopts the same twisted (or symmetrical) structure as the symmetrical communication cable, that is, a pair of insulated wires with different color codes. The wire core is twisted by a twisting machine. Since the loop composed of twisted wire pairs has a cross transposition effect, the interference current in the loop can be offset or reduced, but the cross pitch must be coordinated. When the cross pitch is smaller, the cross effect is better. Therefore, in the process of twisting, it is necessary to strictly control the twisting pitch, and ensure that the pitches of adjacent wire pairs are different and have no even-digit relationship, so as to prevent the loops from interfering with each other. Twisted pairs are usually identified by numbers or ribbon markings, and are then wrapped tightly with non-hygroscopic tape.

(4) shielding. Usually, the cable adopts a shielding structure, and the shielding structure has three types: individual shielding, total shielding, and individual shielding plus total shielding. The shielding adopts the way of 0.05-0.1mm aluminum-plastic composite tape overlapping wrapping or longitudinal wrapping. The aluminum-plastic composite tape is made of plastic film as the base material and coated with aluminum powder on one or both sides. When coating, the aluminum faces inward. In order to ensure the electrical continuity of the shielding and facilitate installation and grounding, a copper wire is placed in the shielding layer as a drain wire, and the cross-section of the drain wire is not less than 0.3mm ² . The aluminum-plastic composite tape shielded cable has a small outer diameter, light weight, softness, moisture resistance, and good shielding effect.

(5) Cable components. The cabling element (cable core) is formed by twisting each twisted pair or sub-shielded twisted pair. The number of pairs of twisted wires can be 1 to 61, and the preferred number of wire pairs is the same as that of ordinary control cables. Core gaps can be filled with non-hygroscopic material to round out the appearance. The filler material should be consistent with the operating temperature of the cable and should be compatible with the contacts. One or more layers of tape are wrapped around the cable core to prevent the cable core from loosening during laying. The cable shall be filled with glass fiber filling rope material, and the non-alkali glass fiber tape shall be wrapped tightly.

(6) Sheath. The sheath is made of fluorine plastic.

The utility model has the advantages of:

The utility model adopts a pair-twisted conductor group, a structure in which the conductor group is twisted with glass fiber ropes, and at the same time, the outer wrapping layer of the cable adopts two layers of non-alkali glass fiber tape adhesive layer water-blocking tape, which not only ensures the structure of the cable It is compact and improves the water resistance of the cable; the cable insulation layer and the sheath layer are made of fluoroplastics, which improves the mechanical strength of the cable and increases the working temperature of the cable to 200°C. It has excellent electrical performance and low dielectric strength. Electrical constant, high thermal stability, low flammability, low moisture absorption, excellent weather resistance; good shielding effect.

Description of drawings:

Fig. 1 is the structural representation of the utility model.

Detailed ways:

Flame retardant and high temperature resistant intrinsically safe computer cable, including several conductor groups 1 and insulation layer 2, several conductor groups 1 are respectively made of two conductors 1-1 twisted with insulation layer 2 wrapped, and several conductor groups 1 are on the outer wall A ribbon 3 is attached, several conductor groups 1 and the ribbon 3 are wrapped with an inner wrapping layer 4, the inner wrapping layer 4 is made of one or several layers of polyester tape, and the inner wrapping layer 4 is wrapped with Sub-shielding layer 5, several glass fiber ropes 6 are placed side by side in the gaps between several conductor groups 1 wrapping sub-shielding layer 5, and then twisted into bundles again. After bundled, sub-shielding layer 5 and several glass fiber ropes 6 are wrapped with Outer tape layer 7, the outer tape layer 7 is composed of two layers of non-alkali glass fiber tapes 7-1 bonded with a layer of water blocking tape 7-2, the outside of the outer tape layer 7 is sequentially wrapped with a total shielding layer 8, a sheath layer 9. The sub-shielding layer 5 and the overall shielding layer 8 are provided with a drain wire 10. The drain wire 10 is made of a copper wire. The cross-section of the drain wire is not less than 0.3mm ² . The insulating layer 2 and the sheath layer 9 are made of fluoroplastics.

Claims (3)

1. flame-resistant high-temperature-resistant intrinsic safety computer cable; Comprise several conductor groups, insulating barrier; It is characterized in that: several conductor groups adopt the conductor pair twist of two equal wrap insulate layers to constitute respectively, are pasted with colour band on several conductor group outer walls, and several conductor groups and colour band are wrapped with interior lapping layer; Interior lapping layer adopts the wrapped formation of one or more layers polyester belt; Interior lapping layer is wrapped with sub-shield, and the gap between several conductor groups of parcel sub-shield is placed with stranded once more bunchy behind the several glasses rope side by side, and the outside of sub-shield, several glass rope is enclosed with outer belting layer behind the bunchy; Outer belting layer adopts bonding one deck waterstop formation between the two-layer alkali-free glass fiber band, and the outer belting layer outside is enclosed with total screen, restrictive coating successively.

2. flame-resistant high-temperature-resistant intrinsic safety computer cable according to claim 1 is characterized in that: be provided with drainage thread in described sub-shield and the total screen, drainage thread adopts a copper wire, and the drainage thread cross section is not less than 0.3mm ²

3. flame-resistant high-temperature-resistant intrinsic safety computer cable according to claim 1 is characterized in that: described insulating barrier, restrictive coating material are fluoroplastics.

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