多喷嘴对置式水煤浆气化炉内颗粒物分布特性的实验研究

Experimental Study of Particle Distribution in Bench-cale Opposed Multi-burner Gasifiers of Coal Water Slurry

颗粒物在气化炉内的分布对合成气成分、碳转化率和壁面熔渣的沉积行为具有重要影响。基于实验室规模的多喷嘴对置式水煤浆气化炉,利用Malvern激光粒度仪和扫描电镜/能谱仪表征了气化炉内颗粒物的粒径分布和组成,并结合碳含量分析了不同氧碳比、气化炉不同轴向位置颗粒物的形成过程。结果表明,气化炉内存在两种不同微观形态的细颗粒物和粗颗粒物。随着氧碳比的增大,沿气化炉轴向向下,颗粒物的平均粒径和固定碳含量均减小,而细颗粒物的含量增加。水煤浆的热解过程主要发生在撞击火焰区,而焦炭的燃烧气化反应不仅发生在撞击火焰区,也发生在管流区,二者消耗的固定碳量之比约为2:1。

Particle distribution in gasifier has important influence on syngas,carbon conversion and slag deposition.Based on a bench-scale opposed multi-burner（OMB） gasifier,particle size and composition were measured by scanning electron microscope-energy dispersive spectrometer（SEM-EDS） and Malvern laser particle size analyzer.The results show that there are two kinds of microstructure of particles in gasifier.With the increase of atom ratio of oxygen to carbon,average particle size and fixed carbon content reduce downwards the axis of gasifier while the mass percentage of fine particles increases.The pyrolysis of coal occurs mainly in the impinging flame region,whereas combustion and gasification take place in both impinging flame region and plug flow region.The mass ratio of burned fixed carbon in the two regions is about 2 1.