Fire resisting cable for electric power transmission

Abstract

The invention discloses a fire resisting cable for electric power transmission. A fire-resistant insulation principle of a mineral insulated cable is fully utilized, and a copper tube sleeve in the mineral insulated cable is replaced by a basalt fiber wrapping material with a higher melting point and a higher electrical insulating property under the condition of maintaining the fire-resistant insulation principle, so that the fire resisting cable provided by the invention has higher fire resistance and high temperature insulation under higher burning temperature; the outer basalt fiber cloth cover is soft and can be turned outward; before magnesia powder is filled, the free end of the outer basalt fiber cloth cover along the length direction is turned outward, inner and outer surfaces are exchanged, the outer basalt fiber cloth cover is matched with the a mold pipe, and a short to-be-compressed space is formed in the mold pipe, so that a compressing pipe or similar compressing device can smoothly get in and out of the mold pipe for compressing; and after the compressing, the pulling or rolling is not required, so that the time and labor are saved, the manufacturing technique is simplified, a large amount of cost is saved, and theoretically, the extracting length of the fire resisting cable is not limited.

Description

technical field [0001] The invention relates to the technical field of power cables, in particular to a fire-resistant cable for power transmission. Background technique [0002] With economic development and scientific and technological progress, the fire resistance requirements for cables used for power transmission are becoming more and more stringent. At present, there are three main forms of fire-resistant cables: the earliest mica tape-wrapped fire-resistant cables, mineral insulated cables that appeared later, and ceramic silicone rubber fire-resistant cables that appeared recently. [0003] Mica tape wrapping refractory cable: the refractory layer is generally made of high-priced refractory mica tape, the wrapping speed is slow, and the mica powder is easy to fall off during the wrapping process, which affects the refractory effect; Brittle, easy to fall off when encountering vibration and spraying, poor fire resistance, it is difficult to ensure that the power line...

AI Technical Summary

Problems solved by technology

[0006] The existing three preparation methods of mineral insulated cables all use a very short but thicker copper conductor to cooperate with an equally short but thicker copper tube to make a cable intermediate product, and then mechanically pull Pulling or continuous rolling, rolling thinner and longer, can obtain the mineral insulated cable with the target outer diameter and length. For example: in the automatic filling method of magnesium oxide powder, the initial copper tube is only 9 meters, and it is drawn after assembly. The longest can reach 700 meters; the reason for such production is: if a copper pipe has the same length as the target cable, such as hundreds of meters or thousands of meters, no matter how high its hardness is, it will happen naturally Deflection bending deformation, at this time it is impossible to insert the copper conductor with the target outer diameter into the copper tube in a coaxial state. It cannot be realized, and the tamping device cannot move smoothly between the copper tube and the copper conductor at all, and it will be stuck when it encounters deflection and bending; such a production method leads to the fact that the length of the mineral insulated cable is not very long, and the manufacturing process is very complicated Complex, very difficult to manufacture, high cost, low yield and output

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