Dense Phase

In dense phase conveying two modes of flow are recognized. One is moving bed
flow, in which the material is conveyed in dunes on the bottom of the pipeline, or
as a pulsatile moving bed. The other mode is slug or plug type flow, in which the
material is conveyed as full bore plugs separated by air gaps. Moving bed flow is
only possible in a conventional conveying system if the material to be conveyed
has good air retention characteristics. Plug type flow is only possible in a conventional
conveying system if the material has good permeability.