This standard ( Part III ) deals with the design of steel bins for storage of bulk materials ensuring satisfactory mass flow and funnel flow ( plug flow) under gravity flow in the case of powdery and granular materials.
IS 9178 Pt.3-1980 history
1980IS 9178 Pt.3-1980 Design Standards for Steel Tanks for Storage of Bulk Materials Part III Tank Design for Mass Flow and Funnel Flow