1. The maximum operating temperature of the heating wire
The maximum operating temperature of the heating wire is the most important performance indicator in the selection process. Here we need to remind customers that the operating temperature of the heating wire refers to the temperature of the surface of the heating wire during operation, not the heating device Or the operating temperature that the heated object can finally reach. In the design and selection of the heating wire, the final heating temperature can be measured according to the electric heating equipment used or the object to be heated. For example, when the heating wire is used for boiler heating, the difference between the furnace temperature and the use temperature of the heating wire is 100 ℃ about. If the heating temperature of the heating wire exceeds the maximum use temperature, the oxidation process of the heating wire is accelerated, the heat resistance performance is reduced, and the service life is shortened.
2. The diameter and thickness of the heating wire
The diameter and thickness of the heating wire is a parameter related to the highest operating temperature. The larger the diameter of the heating wire, the easier it is to overcome the problem of deformation at high temperatures and prolong its service life. When the heating wire runs below the maximum operating temperature, the diameter should be no less than 3mm, and the thickness of the sling should be no less than 2mm.
The service life of the heating wire is also largely related to the diameter and thickness of the heating wire. When the heating wire is used in a high temperature environment, a protective oxide film will be formed on the surface. After a period of time, the oxide film will age and form a cyclic process of continuous generation and destruction. This process is the process of continuous consumption of elements in the electric furnace wire. Electric furnace wires with larger diameters and thicknesses have more elements and have a longer service life.
3. The working atmosphere of the heating wire
The heating wire itself has a certain degree of corrosion resistance, but in a high temperature environment, the corrosion resistance of the heating wire will decrease. At the same time, when the heating wire works in a corrosive atmosphere, the maximum operating temperature will also be affected. Therefore, when selecting the heating wire, its working atmosphere must be considered, such as carbon atmosphere, sulfur atmosphere, hydrogen, nitrogen atmosphere and so on.
The heating wire has anti-maintenance treatment during the production process, but due to various reasons such as transportation and installation, the heating wire may be damaged before use. At this time, the heating wire can be pre-oxidized. The equipment installed with the heating wire is energized in dry air until the temperature reaches 100°C to 200°C below the maximum use temperature, and the heating wire can be maintained for 5 to 10 hours and then slowly cooled.
