The Design of Tungsten Heater

Tungsten heater generally consists of tungsten wire which has a high melting point and high corrosion resistance, and it is mainly used in vacuum metallizing, aluminizing and other decorative items, chrome and other mirrors, plastic products, heating elements. Wolfram heater can be twisted or stranded by tungsten wire into different styles in according with the specific requirements. The tungsten wire can be pure tungsten or doped tungsten wire. Tungsten wire diameter generally in the range between 0.2 ~ 1.2mm. Tungsten is one of several materials commonly used to make electron emitters. The advantage of tungsten is its extremely low vapor pressure even at high temperatures.

The heating cathode was indirectly introduced to the public for the first time in 1927. At that time, there was a big difference of the design of wolfram heater. A kind of tungsten heater is supported by an extruded ceramic insulator and surrounded by a nickel sleeve.

“A” of the picture shows the tube of detector and amplifier commonly used for a wolfram heater before. This heating element needs supply voltage of 2.5 volts. It takes 20 to 30 seconds to warm-up. “B” shows a diameter of 0.02mm tungsten wire wound on a spiral port of alumina insulating tube. Under normal circumstances, the alumina coating covers the entire tungsten wire. “C” in this picture shows a 0.7mm diameter tungsten wire is wound on a spiral port of alumina insulating tube, a molybdenum rod passes the middle of the tube. Such type of wolfram heater generally operates at 5 volts and 60 amperes environment. “D” in the picture shows a diameter of 0.25mm heating sub-branch, and it is pressed in the insulating tube. These four wolfram heater are the most typical form, but in fact, in order to facilitate the use of follow-up processes, the heater element will be made into a variety of shapes and sizes.

• < Prev
• Next >