球团竖炉粉矿问题研究

On Dust & Particles in Pelletizing Shaft Furnace

以济钢球团竖炉为背景,将气固填料床理论和实验相结合,系统研究了炉内粉矿的成因、危害及控制手段·结果表明:竖炉粉矿量为干球与成品球团流量之差,其三种表现形式为爆裂粉矿、落下粉矿及碰撞粉矿,沉积粉矿循环造成炉内部分粉矿难以排除炉外;从干燥带到均热带,粉矿生成速率逐渐减小,粉矿生成总量逐渐增加,但在导风墙下沿处,由于沉积粉矿循环造成此处的粉矿总量骤然下降;炉内粉矿增加,降低了竖炉利用系数,增加了球团工序能耗;控制炉内粉矿的有效措施是实施炉内除尘,即将含尘气体从导风墙下沿引出,经过重力除尘后返回炉内以强化生球干燥·

Based on the theory of gas/solid packed beds, the pelletizing shaft furnace(PSF) of Jinan Iron & Steel Co. Ltd was investigated for the formation, harm and control of the dust and particles(DP) in PSF. Some conclusions are therefore drawn as follows. The quantity of DP in PSF is equal to the difference of mass flux between dry pellets and finished pellets, and DP are formed mainly in three ways, i.e., cracking, free falling and collision. The deposits of cycling DP are difficult to remove out. From the drying zone to the soaking zone the formation rate of DP decreases gradually with the increasing DP accumulation, while the DP accumulation amount decreases abruptly at the bottom of internal vertical air channels(IVAC) because of the cycling of deposited DP. The increasing DP in PSF will result in reducing capacity utilization of PSF and increasing energy consumption for pelletizing process. The efficient way to control DP in PSF is collecting and sucking them out of PSF with gas flow through IVAC bottom by gravitational precipitation. Then, the clean gas flow returns PSF to intensify the drying of green pellets.