Modeling and experimental validation of pressure drop for pneumatic plug conveying

This paper indicates that a variety of models exist to calculate the pressure drop of pneumatic plug conveying. Unfortunately these models are limited in their flexibility and calculate pressure drop only for two extremes, the active and passive case of bulk solid. Until now the stress state within the plug cannot be determined. Therefore a sensor was built to detect wall shear stress, normal stress and the stress state along a moving plug. Beginning with vertical pneumatic plug conveying, the previous models were verified and modified to get new perceptions about formation, stability and pressure drop of plugs.