Application Of Regenerative Combustion In Sintering Of Silicon Carbide Refractory Plate

As the contradiction between limited resources and human development comes to the fore, human’s demand for higher resources utilization efficiency、energy conservation and emission reduction in industry is constantly growing. Regenerative combustion technology(HTAC) has a wide range of application for it meeting the demand of human. Si C refractory slab is crucial to pottery firing, while traditional shuttle kiln(SK) used to sinter refractory slab shows the shortage including heat loss due to high temperature flue gas、terrible temperature distribution、low product quality etc. SK applied with HTAC can effectively recycle the heat loss, corresponding with sustainable strategy, but some problems, such as regenerator deterioration 、 blocking 、 low regenerative temperature during low temperature period, exist in the past application.Based on the principle of HTAC, the traditional SK will be re-designed taking into account the past existing problems. Flue gas flows through the regenerator; self-suction nozzles and regenerative nozzles are installed alternately; reversing valves、combustion fans and smoke exhaust fans are arranged properly. Self-suction nozzles will ensure the combustion during the low temperature period(under 800℃), while the regenerative nozzles will take over the combustion once the temperature is higher than 800℃. The working process of sintering and nozzles will be experimentally discussed. Internal temperature difference of SK、flue gas temperature、thermal efficiency and product quality will be analyzed comparing with those in traditional SK.Under 800℃, self-suction nozzles work, effectively preventing insufficient combustion and insignificantly affecting the energy consumption of SK. The internal temperature difference is reduced due to the work transition of different nozzles in the 800℃. In re-designed SK, high temperature flue gas and the ejecting flame respectively lead to the density difference of gas and the rise of heated air during low temperature period, identical to those in traditional SK. Both phenomenon contribute to the large internal temperature difference. During high temperature period, regenerative combustion reduces the internal temperature difference, because fuel burns with oxygen deficit, and flame and flue gas alternately move around. The temperature of flue gas flowing through the regenerator decreases considerably and waste heat is then transferred to the regenerator. When the regenerator temperature increases to the designed degree, the combustion air will flow through the regenerator by adjusting the reversing valve, then such heat will be transferred to the air and go back to SK. Therefore, the waste heat loss decreases, thus reducing the fuel consumption and increasing the the thermal efficiency to 53.8%. Moreover, because of the better temperature distribution, refractory slab is heated uniformly and its interior stress is weakened, leading to the improvement of product quality.