OCR Text |
Show 1 . INTRODUCTION W e have many actual experiences on sinter plants, but all of them are only the operating way with empirical data. In the sinter packed bed , m a ny phenomena happen simultaneously ,for example it's illustrated in Fig.l , these changes start rapidely after ignition time. Bed ore hopper Row material hopper Sinter reaction zone Sinter cooling zone Sinter end Food Crasher Direction of pallet going Dust collector Fig. l Schematic diagram of sintering machine. O n the other side,waste-gas recirculation systems have been discussed for these several years. But it is not easy to get the inside information of the sinter bed. Then a mathematical simulation model of sinter bed has created to analyze the effect of the use of the waste-gas and to determine the critical conditions under which the temperature of solid in the bed rises normaly. To describe the sintering phenomena in detail, a nonlinear mathematical model is developed and in this model, the coke combustion reactions, the vaporization of moisture, the thermal decomposition of lime stone ,' the melting process of iron are and the solidification process of molten ore. There are some actual applications of the waste gas recycling in the sinter plants. But m a n y sinter plants do not have this system yet, because the benifits are not so clear in using this system. So it is important to estimate the effects of recirculation. W e have constructed the simulation model of waste-gas recirculation process. Through this research, it has been derived many essential meanings for recirculation systems. Performance of the sintering machine is affected by various factors, such as blend ratio of coke, the moisture content of raw material, blend ratio of limestone, melting properties of raw material, atmosphere conditions in ignition furnace (i.e., combustion temperature , moisture concentration of circulation gas and atmospere oxygen concentration). 2. SIMULATION MODEL |