Feeding hopper for filling magnesium oxide powder and magnesium oxide filling method for insulated fireproof cable

Abstract

The feeding hopper comprises a feeding hopper body, and is characterized in that a discharging channel is formed in a discharging opening in the lower end of the feeding hopper body, a vertically-extending shielding gas flow guide pipe is fixedly arranged in the center of the feeding hopper body, and the shielding gas flow guide pipe is arranged in the middle of the feeding hopper body. The lower end of the protective gas flow guide pipe extends to the position below a discharging channel of the feeding hopper body, the protective gas flow guide pipe is fixed in the feeding hopper body through a support, and a protective gas purging hole is formed in the bottom of the protective gas flow guide pipe and located below the discharging channel. The performance of the cable is improved, the compactness is improved, and oxidation is avoided.

Description

technical field [0001] The invention relates to the technical field of cables, in particular to a hopper for filling magnesia powder and a magnesia filling method for insulating fireproof cables. Background technique [0002] Mineral insulated fire-resistant cable, called MI cable, referred to as fire-resistant cable, is a high-conductivity copper wire embedded in a tightly compacted magnesium oxide insulating material in a sturdy and tough seamless copper sheath. The cable can still be energized normally for more than 90 minutes under the flame temperature of 950-1000 ℃. It is mainly used for fire protection systems, emergency lighting systems, alarm systems, automatic fire sprinkler systems, and personnel evacuation systems (safety doors, elevators) Such as high temperature occasions, military facilities and installations and power transmission and distribution lines in riot-proof places, as well as places where the wiring space is relatively narrow. [0003] The insulati...

AI Technical Summary

Problems solved by technology

However, the magnesium oxide powder always accumulates in the copper tube in a fixed direction in the drainage tube. Due to the barrier effect of the copper core in the copper tube, it is difficult for the existing filling process to distribute the magnesium oxide powder evenly on the copper tube copper protection. In the sleeve, the compactness of the magnesium oxide powder is unevenly distributed, which affects the insulation performance of the cable

At the same time, since the air remains in the copper sheath of the copper tube during the filling process, the oxygen remaining in the air will oxidize with the inner wall of the copper core and the copper sheath of the copper tube during the high-temperature heat treatment process of the two annealings in the later stage. , leading to oxidation and blackening of the inner wall of the copper core and the copper sheath of the copper tube after annealing, reducing the conductivity of the fireproof cable and shortening the service life of the fireproof cable

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