Shallow fluid beds of master beads

Shallow fluid beds of spherical ''Master Beads'' (ca. 86% alumina) display nine ''Types,'' of which seven may be useful. Coefficients of heat transfer from a heating tube are highest when the tube is situated near the surface of beds of ''Types'' that display a dense phase. A relatively high standard deviation of solid volume-fraction over time near the surface attests the greater solid ''activity'' in this region