OCR Text |
Show material,blend ratio of limestone,melting properties of raw material,atmosphere conditions in ignition furnace. The volume of air passed through the sinter bed markedly affects the rate of heat transfer and that of coke combustion in the sinter bed. The phenomena happen in the sinterbed are shown in Fig.3. This related to the longitudinal distance from ignition furnace as Fig.4 for temperature changes. Ignition Furnace Longitudinal distance Fig.4 Solid temperature changes with longitudinal cross section. The gas flow resistance of the moisture condensation zone is larger than that of the initial raw sinter bed. The moisture condensation zone forms at a high rate and reaches the bottom of the sinter bed in a short time. As a result, the raw materials containing coke fuel are burned and cause the temperature level to rise approximately 1400°C. The mathematical model is consisted of simultaneous nonlinear partial differential type of fourteen equations having many operation parameters. On the basis of this model,the numerical solutions can be obtained by computer based numerical calculation(eleven million steps for one case), so the virtual operation can be done by computer model.. It is assumed that the drying process is ruled by heat transfer from hot gas flow in the sinter layer. Moisture condensation and drying process can be expressed from the material balance on the fluid. As a resultjt was clarified that the temperature distribution of the surface layer. Through this drying process,the water in the upper solids m o v e into the gas bulk flow as vaper. Then this vapor and waste gas humidity from recirculate gas attach to the d o w n of layer and are cooled by solid, then the vapor condences as the water. The effects of these factors on the reaction rates and the temperature distributions of the sinter bed can be qoantitatively evaluated by the |