The glass tank furnace heated by flame surface has a long history. Although many improvements have been made in the structure in the long-term use process, there are still some serious shortcomings, such as low thermal efficiency, complex kiln structure, large volume, poor working environment and so on. Glass is an electrical conductor at high temperature. The molten glass contains alkali metal sodium and potassium ions, which have electrical conductivity. When the current passes through, Joule heat will be generated. If the heat is large enough, it can be used to melt the glass, that is, use the electric furnace to melt the glass. With the continuous improvement and development of furnace design and electrode, this electric melting method has been widely used.
From the perspective of application effect, the full electric furnace has outstanding advantages, such as simple furnace structure, small floor area, stable control and easy operation, reducing the emission and volatilization of some expensive oxides in raw materials, low noise, reducing the impact on the environment, stable melting process and improving product quality, which are unmatched by fuel furnace.
The main principle of electric furnace is to use electric energy as heat source. Generally, silicon carbide or molybdenum disilicide resistance heaters are installed on the side wall of the kiln chamber, the bottom of the inclined plug, the furnace top and other positions for indirect resistance radiation heating. Some crucible kilns for melting special glass use induction heating, which is heated by eddy current induced in the kiln and the glass liquid. The glass melt in the tank furnace is directly used as the heating resistance. Multiple groups and multi-layer electrodes can be arranged at different depths of the glass melt to heat the glass melt, and the temperature system can be controlled by adjusting the power consumption. When this method is adopted, the temperature of the space above the glass level is very low (called the cold furnace top), so the energy is basically consumed for glass melting and furnace wall heat dissipation, without the loss of heat taken away by the flue gas and the pollution to the environment when the flue gas is discharged, the heat utilization rate is high, and there is no need to set up a combustion system and waste heat recovery system. The full battery kiln can be controlled automatically, requiring less management personnel and good working conditions. The disadvantage is that it consumes a lot of power resources. It is suitable for melting refractory glass, volatile glass and dark glass. The capacity of large-scale battery kiln to produce bottle glass can reach 150t per day.
Post time: Oct-22-2024