Installation of silicon molybdenum rod

The silicon molybdenum bar is somewhat softened at high temperature (above 1500 ℃), and hard and brittle at low temperature. In order to avoid stress during temperature change and facilitate Thermal expansion of components, the free vertical hanging installation method is adopted. The disassembly and replacement of lifting components is also more convenient, and there is no need to wait for the furnace to cool down, but can be heat exchanged.
When hanging silicon molybdenum rods, the following precautions must be taken:
1) The furnace lining material should be made of corundum bricks, and the mass fraction of Fe2O3 should be less than 1%, as it interacts with the protective film to form a fusible silicate, thereby accelerating the damage of the components.
2) The hot furnace gas leaked from the cold end not only increases the heat loss of the furnace, but also burns out the conductive belt clamp and lead wire clamp. Therefore, asbestos clamp is used.
3) As silicon molybdenum bar is brittle material with low Flexural strength, it cannot withstand impact, so protective measures shall be taken during installation to prevent breaking. When connecting the conductive belt, the asbestos clamp (or ceramic clamp) must be installed first, and the clamping force should not be too large.
4) Install the silicon molybdenum rod into the plug brick. In order to avoid the mechanical stress caused by loading and unloading movement, the plug brick shall be a separate brick made of foam corundum brick.
5) Insert the stopper with a silicon molybdenum rod into the prepared gap on the furnace top, with the stopper protruding from the outside of the furnace top for easy disassembly.
6) Connect the conductive tape to the prepared connection bracket, but avoid tension and unnatural twisting mechanical stress on the conductive tape.
7) In order to avoid possible sagging and deformation of silicon molybdenum rod due to Thermal expansion of asbestos chuck, refractory slurry mixed with water glass can be applied at the connection to ensure firm fixation.
8) When lifting, the junction of the cone of the heating part and the furnace wall should be approximately 25mm-3mm apart. The cold end should be exposed 75mm outside the furnace top, and the lower end of the heating part should not be less than 50mm from the furnace bottom.
9) The spacing of silicon molybdenum rods in the furnace should not be less than the center distance of the components themselves.
10) When lifting, attention must be paid to the gravity balance between the two cold ends and the wiring part, otherwise it may cause bending and deformation of the heating part