Magnesium oxide powder feeding hopper and copper pipe copper sheath magnesium oxide insulated cable filling method

Abstract

The invention discloses a magnesium oxide powder feeding hopper and a copper pipe copper sheath magnesium oxide insulated cable filling method, the feeding hopper comprises a feeding hopper body, the feeding hopper is characterized in that a discharging channel is arranged at a discharging port at the lower end of the feeding hopper body, and shielding gas interlayers communicated with each other are arranged outside the feeding hopper body and the discharging channel; a half of the interlayer of the discharging channel extends downwards to form a semicircular extending part, a protective gas purging hole is formed in the inner side wall of the semicircular extending part, and the bottom end of the semicircular extending part is sealed. 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 magnesium oxide powder feeding hopper and a method for filling a copper tube and copper sheathed magnesium oxide insulated cable. 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 90min under the flame temperature of 950-1000℃. It is mainly used for fire protection system, emergency lighting system, alarm system, automatic fire sprinkler system, personnel evacuation evacuation system (safety door, elevator) 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 narr...

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

Images