How to Choose Molybdenum Electrode

General molybdenum electrode diameter between 35 ~ 75mm, and the choice of molybdenum electrode size is mainly based on the size of the current density to determine. Typically, the boron-doped glass is selected to have an electrode with a diameter of φ50 mm, and the advancing of the electrode during operation is determined by the magnitude of the actual current density. For vertical electrodes, the electrode continuation problem is taken into account when the density value reaches 0.8 A / cm2. For the furnace age longer (more than 4 years) of the kiln with the electrode consumption, the current density increases, if the electrode is not ready to continue, the current density also need to be controlled at a lower value, molybdenum electrode current density running at 0.6 A / cm2 or less, the electrode is almost no consumption. The current density of the electrode melting the borosilicate glass is between 0.42 and 0.49A / cm2, and the electrode is hardly consumed in two years without further use.

Soda-lime glass and other low-resistance glass, the resistivity is less than 15Ω · cm, the electrode is difficult to control the current density of 0.6A / c m2 below, because of its low viscosity and low resistivity, often use φ75mm electrode. In addition, in the course of the operation of the electrode will have different degrees of wear and tear, so the electrode must be made into the type. From the electrode operating costs, the plate electrode consumption less, more suitable for soda-lime glass melting.

The conductive distance of the electrode has a direct effect on the operating life of the electrode. The electrode is too close, the operation was low voltage high current state, this local high power will not only reduce the life of refractory materials, and will increase the electrode wear, to bring defects to the product. In addition, the current density value is too large, the impact of the destruction of the electrode even greater. In the range of voltage tolerable range of the welding kiln, the operation scheme of high voltage and low current can improve the efficiency, but it must meet the requirements of melting process and operation safety. When the correct process design to establish a low voltage high current operating state, increase the electrode conductive area can improve the electrode life, that is, use a larger diameter rod electrode, or multi-electrode and use, or increase the number of electrodes , Or when the process permits the use of plate electrodes.