Generally, the diameter of molybdenum electrodes is between 35 and 75mm, and the size of molybdenum electrodes is determined by the current density. When smelting borosilicate glass, an electrode with a diameter of about 50mm is usually selected. The promotion effect of the electrode in operation depends on the actual current density. For vertical electrodes, electrode continuity should be considered when the density reaches 0.8A/cm2.
As electrode consumption increases, the current density of electric furnaces with longer furnace ages (more than 4 years) increases. If the electrode is not ready to continue, the current density needs to be controlled at a lower value. When the current density of the molybdenum electrode is lower than 0.6A/cm2, the electrode is almost not consumed.
The resistivity of low-resistance glass such as soda-lime glass is less than 15Ω·cm, so it is difficult for the electrode to control the current density below 0.6a/c·m2. Due to its low viscosity and low resistivity, 75mm electrodes are often used. In addition, the electrodes will produce varying degrees of loss during operation, so the electrodes must be carried over. From the perspective of electrode operating costs, plate electrodes consume less and are therefore more suitable for the melting of soda and lime glass.