Industrial Smelting Furnace Coarse End Type Silicon Carbide Rod

If the resistance values of the components differ, in a series connection, the silicon carbide rod with higher resistance bears a more concentrated load, which can easily cause a rapid increase in resistance and a shortened lifespan. Silicon carbide rods are generally used in a combination of series and parallel wiring. It is recommended to connect two rods in series as one group and then connect multiple groups in parallel. Especially when the furnace temperature exceeds 1350°C, parallel connection is necessary. For three-phase wiring, an open delta connection is recommended. Practice has shown that a higher load density results in a larger temperature difference between the heating element's surface and the furnace chamber. A higher load density leads to a higher surface temperature of the rod, faster resistance increase, and a shorter component lifespan. Therefore, the surface temperature load, density, and furnace atmosphere of silicon carbide rods are directly proportional to the aging rate of the components and inversely proportional to their lifespan. During installation, first select the appropriate silicon carbide rod components based on the electric furnace, ensuring that the resistance values do not differ significantly, with a tolerance of around ±0.1 being optimal. For power supply equipment, it is recommended to use devices with a wide voltage regulation range and smooth continuous voltage adjustment (such as magnetic voltage regulators, silicon-controlled rectifier DC voltage regulators, etc.). If a step-voltage regulating transformer is chosen, one with small voltage steps and multiple regulation levels should be selected. To extend the lifespan of silicon carbide rod components and ensure safe use, multiple series connections should be avoided. Wiring methods for silicon carbide rod components can include parallel, series, delta, star, and other configurations; however, parallel connection is superior to series connection, as it can balance load imbalances, while multiple series connections exacerbate imbalances and increase operating voltage. Surface load density is inversely proportional to furnace temperature; the higher the furnace temperature, the lower the allowable surface load density. Overloading can cause silicon carbide rods to overheat and decompose, leading to surface peeling and burnout of the heating section. To ensure component lifespan, when using series connections, the number of rods in a series branch should not exceed three, and it is crucial to avoid operating heating elements under overload conditions. Generally, the value should be controlled between 3–8 W/cm². By adjusting the power load applied to silicon carbide rod components, the surface load density can be reduced. Even if the kiln temperature is high, a relatively long lifespan can be maintained by using a smaller load and lower surface load density.