Several Problems in the Use of Silicon Carbide Sticks
Silicon carbon rod is silicon carbide as the main raw material of non-metallic electric components, with high temperature, anti-oxidation, high temperature unchanged
Shaped and the unit area of the load and other advantages, which is widely used as aluminum and its alloy melting furnace and insulation furnace electric components.
Silicon carbon rod with star connection method, the terminal voltage of 380 volts, the use of the maximum temperature of 1600 `C, the service life of 200. Hour or so. As the aluminum and its alloy melting temperature is generally below 1000 ℃, if the use of reasonable, life expectancy of up to 3000 hours, on the contrary, life is greatly reduced. In addition to improving the quality of silicon carbon rod itself, to explore a reasonable way to use is to improve its service life, reduce costs and improve production efficiency of the important way. I plant has many years of practical experience, will now use the process should pay attention to several issues and common exchange.
(1) Before the use of silicon carbide rods, should check whether there is a slight crack, this crack is usually generated in the storage, handling and replacement before the furnace. If used in the case of cracks, with the temperature rise, intergranular crack expansion, resulting in intergranular fracture, followed by silicon carbide rod collapse on the whole.
(2) silicon carbide rods should be used before the determination of the resistance value should try to make each phase resistance values match the same, which is conducive to the balanced growth of resistance, easy to control the furnace temperature and extend the life of silicon carbon rods. Practice has proved that the same resistance furnace in the
Silicon carbide rods to the difference between the value should not be greater than 2% is the best.
(3) silicon carbon rod cold end wiring parts to wrap a thin layer of aluminum, so that the conductive chuck and cold junction in close contact. If the contact is not close, the conductivity is poor, serious will make the cold end and conductive clip burned and can not be used normally.
(4) feeding, mixing, slagging, refining operation, the action range can not be too large and too fierce, so as not to touch the silicon carbide rod or aluminum liquid splashed on the surface of silicon carbon rod, causing its break or local resistance changes The resistance value of each phase match is inconsistent, greatly reducing its service life.
(5) found that silicon carbide rods burn broken, it should be replaced in a timely manner. It is best to replace the batch at the same time, do not sporadic replacement, to avoid the resistance caused by inconsistent elements burned. Has been "aging" of the silicon carbon rod should also be a one - time replacement. In order to make full use of the replacement of silicon carbon rods, can be measured separately resistance values, pick out the resistance value of roughly the same silicon carbon rods in batches re-use.
(6) silicon carbide rod before loading, should be fully preheated to prevent its rapid heating and damage, if doing so in the operation of the difficulties, it should also allow it to slowly warming up to high temperature, do not suddenly rise to high temperatures.
(7) silicon carbide rod should be used continuously as much as possible, so that it can extend its service life.