Heating element of muffle furnace

Working principle and classification characteristics of muffle furnace heating elements

Electric heating wire is one of the most common heating elements in muffle furnace. Its function is to generate heat after being electrified and convert electric energy into heat energy. Electric heating wire is widely used in many kinds of high temperature muffle furnaces, so it is widely used in medical, chemical, electronic, electrical, metallurgical machinery, ceramic glass processing and other industries.

1. The working principle of electric heating wire is the same as that of other metal heating elements. It is the electric heating phenomenon after the metal is electrified. Electric heating means that after the current passes through the conductor, the current will produce a certain amount of heat and be transmitted by the conductor. The electric heating wire itself is a metal conductor. After being electrified, it will emit heat and provide heat energy.

2. The types of electric heating wires are classified according to the chemical element content and structure of electric heating wires. The types of electric heating wires are Fe Cr Al alloy and Ni Cr alloy. As electric heating elements, the two kinds of electric heating wires have different functional characteristics.

3. The advantages and disadvantages of Fe Cr Al alloy heating wire are the high operating temperature. The highest operating temperature of Fe Cr Al alloy wire can reach 1400 ℃. Fe Cr Al alloy wire has long service life, high resistivity, high surface recombination and good oxidation resistance. The disadvantage of Fe Cr Al alloy wire is that its strength is low in high temperature environment. With the increase of temperature, the plasticity of Fe Cr Al alloy wire will be enhanced, that is to say, the Fe Cr Al alloy wire is easy to deform in high temperature, and it is not easy to repair after deformation.

4. The disadvantages of Ni Cr alloy electric wire the advantages of Ni Cr alloy wire are high strength in high temperature environment, not easy to deform and change structure after long-term high-temperature operation, and the plasticity of Ni Cr alloy electric wire is good at room temperature, and the repair after deformation is relatively simple. In addition, Ni Cr alloy wire has high emissivity, no magnetism, good corrosion resistance and long service life. The disadvantage of Ni Cr alloy electric heating wire is that the operating temperature can not reach the level of the previous one. Nickel is needed in the manufacture of Ni Cr alloy electric heating wire. The price of this metal is higher than that of iron, chromium and aluminum. Therefore, the manufacturing cost of nickel chromium alloy electric wire is high, which is not conducive to cost control.