具有不同粒度的两种工业煤粉竖直管气力输送特性

Vertical Pneumatic Conveying of Two Industrial Pulverized Coals with Different Particle Sizes

在自主搭建的工业级管径(内径50mm)气力输送实验平台上,分别进行了晋城煤和羊场湾煤两种工业煤粉的气力输送实验,考察了由粉体物性导致的竖直管单位管长压降、输送流型及稳定性等方面的差异。研究结果表明,粒径、粒径分布及其均匀性是导致其竖直管输送特性不同的主要因素;输送量一定时,相同表观气速下两种煤粉静压降相同,低表观气速输送的晋城煤和羊场湾煤竖直管单位管长摩擦压降相差不大;随着表观气速的增加,较大粒径的晋城煤竖直管单位管长摩擦压降逐渐大于较小粒径的羊场湾煤,且两者差异性随着表观气速的增加逐渐增大。在表观气速增大的过程中,粒径的差异使得两种煤粉产生不同的流型转变过程,在此过程中输送稳定性变化有所不同,整体而言,晋城煤的稳定性较差。研究为气流床干煤粉气化技术提升煤粉输送稳定性提供了有效参考。

Conveying experiments of two industrial coals（Jincheng coal and Yangchangwan coal） were studied in a home-built pneumatic conveying facility with a pipe diameter of 50 mm. Effects of vertical pressure drop, flow pattern and conveying stability caused by powder physical properties were studied. The results show that the differences in particle size, particle size distribution and homogeneity of the coal can all affect transportation properties. The static pressure drops of the two coals are equal, but the friction pressure drops are more complicated. The results show that the friction pressure drop of Jincheng coal is close to that of Yangchangwan coal at low superficial gas velocities, which is larger at high superficial gas velocities. With the increase of superficial gas velocity, the transition processes of flow pattern are different due to different particle sizes, which results in different conveying stability. Jincheng coal shows poor stability at high superficial gas velocities because of the formation of high-frequency plug flow pattern. This study provides useful information for stable conveying in pulverized coal gasification technology.