Magnesia powder pouring method in large size mineral insulation fireproof cable production

Abstract

The invention relates to a filling method of magnesia powder in preparation of a fireproof cable, in particular to a filling method of magnesia powder in the preparation of a long length mineral insulation fireproof cable. The invention mainly solves the density problem when the magnesia powder is filled. The invention adopts the technical proposal that: the filling method of magnesia powder in the preparation of the long length mineral insulation fireproof cable comprises the following steps: a. the magnesia powder is filled in a copper conductor formed by vertical welding by a transport unit; b. compressive force of 300 to 500MN/m3 is exerted when the magnesia is filled, and the compressed magnesia powder is bonded together; and c. the magnesia powder is compacted by a vibrocompaction device to cause the density of the magnesia powder in the tube to be close to that of the powder lot of the magnesia cable.

Description

Technical field: [0001] The invention relates to a filling method of magnesium oxide powder in the preparation of fireproof cables, in particular to a filling method of magnesium oxide powder in the preparation of large-length mineral insulated fireproof cables. Background technique: [0002] As the incidence of electrical fires in fires increases year by year, according to statistics, electrical fires accounted for 80% of the top ten fire cases in the country in 1995. Therefore, the requirements for fire protection of wires and cables are becoming increasingly urgent. The drawing process of insulated copper sheath has the following disadvantages: 1. The length of the production cable is short, and the maximum length of the larger section is only tens of meters. Many intermediate joints are required during laying, which is not only expensive and difficult to lay, but also greatly increases Potential failures in cable operation. 2. The cable material utilization rate of the ...

AI Technical Summary

Problems solved by technology

[0002] As the incidence of electrical fires in fires increases year by year, according to statistics, electrical fires accounted for 80% of the top ten fire cases in the country in 1995. Therefore, the requirements for fire protection of wires and cables are becoming increasingly urgent. The drawing process of insulated copper sheath has the following disadvantages: 1. The length of the production cable is short, and the maximum length of the larger section is only tens of meters. Many intermediate joints are required during laying, which is not only expensive and difficult to lay, but also greatly increases Hidden dangers in cable operation

2. The cable material utilization rate of the drawing process is low, the loss is large, and the cable cost is high. The average material waste is 4.2%, and the product qualification rate is up to 85%.

3. Multiple times of electric furnace annealing during the cable drawing process consumes a lot of power, and the average power consumption accounts for 60% of fuel power

In view of the above situation, the promotion and use of fireproof cables produced by the traditional drawing process are subject to certain restrictions

The mineral insulated cables of Baosheng Science and Technology Innovation Co., Ltd. are magnesia insulated fireproof cables. The cable has the following characteristics: the long-term use temperature of the bare cable is 250°C, and it can supply power for 3 hours at 950°C to 1000°C, but it does not introduce how the magnesia is filled. Pretend