Vacuum high temp. electric heating pipe and product tech. thereof

Abstract

A vacuum high temperature heater tube includes a refractory steel outer guard tube and a hot wire, in which, a mixed filling layer is set between the surrounding of the hot wire and the guard tube, a seal casing cap is set at the line end, an insulation porcelain base is set out of the seal casing cap, a screw cutting sleeve is set at the outer end of the insulation porcelain base and the back of the cutting sleeve is fixed to the outer wall of the guard tube. The production technology includes: cleaning the guard tube, drying, removing hydrogen, winding the carbon hot wire on a stainless steel rod in twist and putting it at the center of the guard tube, filling a matched MgO compound material uniformly and vibrating it to draw out the stainless steel rod steadily to be filled, shrinking the tube, heating it to 150deg.C for 1 hour to be vacuumed and removing moisture till 500Kohm insulation resistance, filling a seal casing cap, pressing tightly the insulation porcelain base with the screw cutting sleeve to be welded with the outer wall of the guard tube, shaping, testing and verifying and packing the product.

Description

technical field [0001] The invention belongs to the improvement of electric heating tube technology, and mainly relates to all vacuum high-temperature electric heating tubes and their production processes. Background technique [0002] Existing common metal electric heating tubes such as figure 1 As shown: it mainly includes a metal outer tube 1, a resistance wire 3 and a magnesium oxide filler 2. The resistance wire 3 is located in the metal outer tube 1, and the magnesium oxide filler 2 is filled between the metal outer tube 1 and the resistance wire. The end is sealed with 704 sealing insulating glue 4 and insulating porcelain 6, and the resistance wire 3 is connected to the terminal post 5. Its production process is: [0003] Clean the metal outer casing → dry → wear resistance wire → fill evenly with magnesium oxide fine powder and shake the powder to make it compact → shrink the tube → heat and drain moisture → seal the end with 704 glue and insulating ceramics → do ...

AI Technical Summary

Problems solved by technology

[0005] 1. The seal is not strict, it is easy to absorb moisture, the insulation level is low, there are potential safety hazards, and it is easy to break down;

[0006] 2. The working temperature is low and the application range is small (only used between normal temperature and 500°C);

[0007] 3. It is easy to burst when the temperature is too high, and the service life is short (between 1000 and 2000 hours);

[0008] 4. When using it, it is necessary to preheat and drain the moisture first, which consumes a lot of energy and increases the working time

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