The purpose of tempered Glass Heat Soak Test is to make the glass, which exists to be exploded by itself, burst to pieces before leaving the factory, and in order to guarantee the glass provided to customers will not explode spontaneously. The immanent cause of the glass explosion spontaneously is that manufacturers mix Nis impurity during producing glass, and there is a little Nis existing in about every seven tons glass. Nis has two kinds of crystal, in high temperature(T> 380°C ) it is α-Nis and in low temperature it is β-Nis. The glass will cool down quickly when it is toughening and α-Nis can't transfer to β-Nis in time. During the using period α-Nis changes to β-Nis slowly, with the cubage bulge 4% and makes the glass explode spontaneously. The function of homogeneous stove is to make α-Nis change to stable and low temperature β-Nis completely and then prevent the glass from exploding when it is used by the customers. Because Nis converse speed has something to do with the temperature, the uniformity of the temperature in the stove is very important. When the temperature is 280°C , the converse time is only one hour; but when the temperature is 250°C , it needs 100 hours. So the distributing of the temperature in the stove is very important, otherwise some glass after several hours is still not changed. It equals no affection. HSO series homogeneous stove adopts hot wind cycle method to heat, and there are fine designed cycle wind pipes inside the stove, the cycle route is optimized by hydrodynamics and this assures that when the stove is full of glass, it can also heat uniform everywhere. |
