Low-velocity pneumatic conveying of powders

Most studies into low-velocity pneumatic conveying are confined to the transportation of coarse granular materials that display natural slugging ability. However, some powders also exhibit natural slugging tendency and can be good candidates for low-velocity pneumatic conveying. This paper studies the conveying characteristics of a semolina powder over a broad range of operating conditions. From this study it is found that the low-velocity pneumatic conveying performance of powders is quite different to coarse granular materials. The most significant effect appears to be slug velocity. Based on experimental results, a model for predicting pipeline pressure drop in low-velocity pneumatic conveying of powders is obtained by modifying a model that was developed previously for coarse granular materials. The results predicted by the modified model agree well with the experimental data.