Dense phase (plug) conveying — observations and projections

Dense phase (plug) flow has been reviewed beginning with the past work of researchers and an analysis of their findings. An analysis of what is known and what is not understood has been attempted. With this in mind some initial work into looking at the basics of a plug from a fundamental set of experiments has been carried out. This information provides with some basic understanding often pointing at complexities and the need to delve more into the topic. The basic physical properties of the plugs have been measured in an effort to begin to provide a predictive mechanism for the designer. Predicting the behavior of dense phase (plug) conveying operations is a goal. It is known that the material and piping properties and geometries are crucial factors in this endeavor. Ideally it would be desirable to have a series of simple tests for the material itself that would provide us with a framework for projecting the design of the dense phase system. These material properties could unify all the data we have on dense phase (plug) conveying. In addition one may conjecture that the determination of the system parameters assessing such topics as the ratio of vertical to horizontal transfer lengths and the numbers of bends seems prudent for analysis.