Bubble technology at the bottom of glass kiln is a new technology developed in 1950s. In foreign countries, it was installed in most furnaces in 1960s, and it was also adopted in China in more than ten years after 1980s. The application practice shows that bubbling plays a positive role in actual production, especially the law of the relationship between bubble parameters and temperature distribution in the kiln has not been fully grasped. Chen Jinghua of Yancheng Institute of Technology and Tang Jiajia of Qiqihar Institute of Light Industry established a glass model kiln according to the similarity theory, selected the simulated liquid and established the operating parameters of the simulated kiln, and simulated the actual production process of glass on the model kiln which is basically similar to the actual melting furnace by physical simulation, realizing the similarity of flow and temperature distribution, and tested the temperature distribution before and after bubbling in the model kiln and when the bubbling parameters changed. The following conclusions are obtained:
1, bubbling reduces the surface temperature.
Bubbling has a forced convection effect on the simulated liquid, which strengthens the thermal convection between the hot spot and the feeding port and brings heat to the feeding port. This effect will first reduce the surface temperature in actual production, which can increase the temperature difference between the radiant heat source and the surface, enhance the radiation ability and improve the heat utilization rate. Secondly, the increase of the feeding port temperature will promote the melting of the batch and improve the melting rate.
2, bubbling improves the temperature uniformity
On the horizontal and vertical interface, the slope of the temperature curve without bubbling is greater than that of the temperature curve with bubbling, which shows that the temperature of the kiln tends to be uniform in both the length and width directions after bubbling, and the reduction of the temperature difference in the width direction is beneficial to improve the uniformity of glass liquid and the glass quality. In the depth direction, bubbling increases the temperature of the middle layer and the bottom of the pool, especially the bottom of the pool, which can reduce the amount of stones. In order to improve the glass quality, it is not necessary to reduce the depth of the tank, and there is no need to worry about the frozen material problem caused by the low temperature at the bottom of the tank for the kiln with deep clarification tank and sinking liquid hole structure. In addition, the improvement of temperature uniformity is also helpful to accelerate the homogenization of glass and improve the quality and yield.
3. Influence of bubbling pressure
With the influence of bubbling pressure, the above-mentioned effects are more obvious, but it does not mean that the greater the bubbling pressure, the better. After the bubbling pressure increases to a certain extent, the effect is basically unchanged, and it is unnecessary to increase the pressure again.