An experimental investigation on plug formation using fuzzy cottonseeds

Within the field of pneumatic conveying horizontal (Plug-1) and vertical plug flows have been investigated only in the context of cohesive fine powders. This paper considers a series of experiments using fuzzy cottonseeds, which greatly differ in particle and bulk properties from fine powders, to investigate plug formation. In this study, several possible dense phase behaviours were observed, which were consistent in vertical and horizontal orientations and mostly influenced by the batch size of feeding into the rig due to its influence on particle arrangement. Particle arrangement at the plug base or rear was found to be critical for achieving stable plugs, with a requirement of the rear or base batch having the length of more or equal to pipe diameter. This work sheds light on the general features and mechanisms governing horizontal and vertical plug formation.