Investigation On The Low-energy Consumption And High-efficiency Glass Melting

The energy saving and consumption reducing has been a key question in the glass industry that hinders its advance and development, there is a gap between China and overseas, the average heat consumption has reached up to7000KJ/Kg of our glass-making, which is the triple of theoretical heat consumption and10percent higher than the heat consumption in developed countries; The glass furnace thermal efficiency of industry developed countries is about30%-40%, but our country is only average20%～30%. It costs ten million tons sandstone per year in China and produces three million tons ultrafine powders, which should be thrown out, otherwise it will bring much harmness, and this leads to the great waste of resource. The glass melting and refining costs about70percent heat consumption of all the heat consumption in the glass-making, so it is a crucial question to reduce the heat consumption of glass-making for the flat glass development in our country.There are many questions in the traditional siemens-type glass melter with refractory-line:the high temperature、long time and high heat consumption of glass melting and refining; The conventional refractory-lined furnaces fired mainly with air and natural gas or oil as fuel, which is high costs and produces a large amount of emissions such as CO2、 NOx and SOx which aggravate the environment; The thermal insulation performance is bad of glass furnace and the heat dissipates severely; The flame erodes the refractory greatly and the short life of furnace. Whereas the questions above mentioned, some ways and advance have been put forward by some experts and scholars:using more efficient burners、 more insulation materials、 improving the furnace design as well as using oxygen instead of air etc. But all these can not solve radically the questions in the glass melting.The research mainly through the granulation of the loose glass batch and make a comparison with the loose glass batch. The granulated glass batch can accelerate glass melting in some degree and reduce the glass melting time. We broke the conventional glass melting craftwork with siemens-type and studied the glass batch melting by using DC arc plasma, the plasma has the special strongpoints:high energy density、 high chemical reactivity、 easy and rapid generation of high temperatures as well as rapid quenching capability and high enthalpy etc. The research system adopted75SiO2-10CaO-15Na2O (Wt%), we studied the melting reaction on the different power, the structure、 fracture morphology、 mass loss、 chemical composition of samples were characterized by X-ray diffractometry(XRD)、 Scanning electron microscope(SEM)、 thermogravimetric-mass spectroscopy analysis(TG-MS)、 X-ray Fluorescence(XRF). When the power of plasma is30kw to melt the glass batch, it can get the best melting effect. It can reach up to91.61percent of vitrification degree, the bubbles disappeared, and0.66percent of mass loss by thermal analysis. Using the DC arc plasma to melt the glass batch can reduce the melting time effectively and shorten the refining time, the research may provide new ways and thoughts for the energy saving and consumption reducing of Chinese glass industry.