The wiring method of silicon carbide rods: If the resistance values of the components are different, the high resistance silicon carbide rods will be more concentrated when connected in series, which will easily cause the resistance of a certain root to increase rapidly and shorten the life.
Silicon carbide rods can be connected in parallel, in series or a mixture of the two. It is recommended to use 2 in series to form a group and then multiple groups in parallel.
Especially when the furnace temperature exceeds 1350℃, it must be connected in parallel.
It is recommended to use open delta wiring for three-phase wiring. Practice has proved that the greater the load density, the greater the difference between the surface temperature of the heating element and the furnace temperature.
The higher the load density, the higher the surface temperature of the rod, the faster the resistance growth, and the shorter the life of the heating elements.
Therefore, the surface temperature load, density, furnace atmosphere, and temperature of the silicon carbide rod are directly proportional to the aging rate of the component, and inversely proportional to the life of the component.
Silicon carbide components in continuous furnaces and batch furnaces, the former has a longer life.
This is because the surface of the device is oxidized to form a silicon dioxide film during use.
Long-term use will increase the silicon dioxide film and increase the resistance.
The silicon dioxide film expands and contracts abnormally near the crystallization critical point (270°C).
Because the temperature always fluctuates at this temperature during intermittent use in intermittent kilns, the silica film is repeatedly broken to accelerate oxidation.
Therefore, when the furnace temperature is often lowered to room temperature, the resistance will increase sharply, which will shorten the service life of the components.