The basic requirements of electric heating tube for electric heating wire
Today, I will talk about the core heating element of the electric heating tube-the electric heating wire. There are also requirements for the heating wire that can be called the heating element in the electric heating tube. The specific requirements are as follows:
(1) Sufficient heat resistance, that is, no or little oxidation at high temperature;
(2) Have certain mechanical strength at high temperature;
(3) The specific resistance is large, otherwise the tubular heating element has to be made very long, which is not easy to install;
(4) The smaller the resistance temperature coefficient, the better;
(5) Good processing performance, can be processed into linear, ribbon or spiral shape, and has good welding performance;
(6) Long-time work does not age;
(7) The source of materials is based on domestic, and the cost is low.
At present, the commonly used materials in China are nickel-based alloys and iron-based alloys. The iron-chromium-aluminum alloy is more brittle than the nickel-chromium wire when heated, but because it is in the tube and is compacted in the filler, the heating wire cannot receive any color mechanical pressure during heating, so the above mentioned The shortcomings of brittleness obtained do not exist for the manufacture of tubular electric heating elements. In actual production, the specifications of the heating wire are between 0.15~1.6mm. When the wire diameter is ≥0.3mm, O0r25A5 iron-chromium aluminum alloy wire is generally used, and when the wire diameter is p≤0.25, Or20Ni80 nickel-chromium alloy wire is used.
Specifically, in the process of producing electric heating tubes, we will always ask about the working environment of the electric heating tube, the surface load of the electric heating tube and the working temperature before designing the heating tube to select the appropriate heating wire material. Our company mainly uses the steel filament of Beijing Shougang or the high-end German BGH heating wire.