操作参数对直接提钒焙烧竖炉热工特性的影响

Influence of operation parameters on thermal characteristics of roasting shaft furnace for direct extracting vanadium

以局部热力学非平衡模型为基础,建立钒钛磁铁矿直接提钒焙烧竖炉三维稳态气固传热模型,借助Fluent软件的UDF功能,将竖炉内的化学反应热以内热源的形式编译到能量方程中,并利用实验获得的料层压降公式修正动量方程源项中的黏性和惯性力项系数,开展竖炉操作参数对炉内热工行为的影响研究。研究结果表明:在生产可调范围内,随着球团当量直径的减小,在焙烧段内球团温度会随之升高,在冷却段内球团温度会随之降低,且竖炉保温段延长;对于产能为330 t/a的中试竖炉,其适宜的操作参数为:冷却空气流量544 m3/t,竖炉下部气固水当量比约0.95;焙烧风流量1 082 m3/t,焙烧风与冷却风配比2:1;球团当量直径46 mm。

Based on the local thermodynamic non-equilibrium model, the three-dimensional stable-state gas-solid heat transfer model of roasting shaft furnace for compact extracting vanadium was established. By virtue of user-defined functions in Fluent, the chemical reaction heat was defined within the solid energy equation in the form of heat source, and the air resistance coefficients in the source terms of momentum equation were corrected and defined by the layer pressure drop formula in shaft furnace. The effect of operation parameters on the thermal behavior in shaft furnace was conducted. The results show that in the adjustable production range, the pellet temperature decreases in the roasting section and increases in the cooling section with the increase of pellet diameter, besides, the soaking section is extended. For a given pilot scale roasting shaft furnace of 330 t/a, the suitable operating parameters are as follows： cooling air volume is 544 m^3/t, the gas solid water equivalent is approximately 0.95, the roasting air volume is 1 082 m^3/t, the ratio of roasting air volume and cooling air volume is 2, and the suitable pellet diameter is 46 mm.