Modifying your storage vessel for trouble-free continuous purging or conditioning — Part I
This two-part article explains how a conventional storage silo or bin can be modified to provide continuous purging or conditioning of dry bulk materials. Information covers the six criteria your plant's design engineer or a consulting bulk solids handling engineer can use in designing the vessel for successful operation. Part II will appear in December.
By introducing an upward-flowing gas into a storage silo or bin for handling dry bulk materials, you can use the vessel as an economical continuous purge vessel for stripping volatiles or as a continuous conditioning vessel for controlling material moisture. In a purge vessel (also called a purge column), a gas -- typically air or nitrogen -- passes upward through the downward-flowing material to strip volatiles from it, called devolatilization. Typically, the material is polymer and the volatiles are residual monomers and solvents. In a conditioning vessel, moisture (also considered a volatile) is added to or removed from a downward-flowing material stream by injecting upward-flowing air with a controlled humidity level into the material.