Furnace Cross Belt Uniformity

The cross belt uniformity is an important factor that can have a significant influence on the quality of the fired samples in a conveyor belt furnace. Good cross belt uniformity and temperature stability have been reported to lower the contact resistance in photovoltaic’s and coefficient of thermal resistance in thick film hybrids. With increasing product dimension, especially in thin film photovoltaic’s, non uniformities in temperature across the belt can cause significant temperature gradients resulting in breaking of  the substrate materials.

For this reason, our furnaces are manufactured with utmost care to ensure minimal variation across the belt. Our furnaces use a fully enclosed heater board that is designed to provide uniform and stable heat distribution across the entire belt. Also, the use of precise Shimmaden temperature controllers enables the furnace to respond quickly to variation caused by the load. Along with this, the superior insulation design ensures minimal heat loss across the edges of the furnace.

Below is an illustration of cross belt uniformity check performed on a 750mm wide belt furnace. It has been observed that the temperature variations between the centre and the two edges at any instance have always been less than a 2 degree centigrade. This precise control on temperature variations across the belt helps in improving the process yield.

Why Zirconia Oxygen analyzer needs Furnace to warm up before they can show oxygen ppm level

The Zirconia sensor is a high temperature electrochemical type.  The Zirconium oxide, treated with Yitium oxide and plated with platinum on opposite ends acts as the sensor.  At elevated temperature, pores are formed in the zirconia lattice allowing oxygen movement from higher concentration to lower concentration, based on the partial pressure of oxygen.  To create this partial pressure differential, one electrode is usually exposed to air (20.9% oxygen) while the other electrode is exposed to the sample gas.  The movement of oxygen ions across the zirconium oxide produces a voltage between the two electrodes, the magnitude of which is based on the oxygen partial pressure differential created by the reference gas and sample gas.