POWDER FLOWABILITY and BULK SOLIDS FLOW PROPERTIES
When designing equipment for handling liquids or gases, one often consults historical or published bulk solids data. In the case of bulk solids equipment design, generally, powder flowability data are not available, often incomplete, or may be non-representative.
Powder flow properties are crucial for understanding costly bulk solids flow problems, like bridging, ratholing, flooding or rate limitations with fine powders, or segregation . For designing a new silo/bin/hopper, feeder, chute, conveyor or other bulk solids handling equipment, powder flow properties tests, such as those listed below, are critical.
Critical powder flow properties
Cohesive strength – powder flowability; bridging and ratholing tendencies
Wall friction – hopper angles to achieve mass flow
Compressibility – bulk density as a function of consolidating pressure
Permeability – limiting discharge rates from hoppers
Angle of repose – angle of pile of material at rest
Loose/tap density – tests run per protocols in USP I and USP II
Chute – chute angles required to maintain flow after impact
When evaluating bulk solids properties, it is vital to replicate actual or expected process conditions.
Our experience is established on having tested over 10,000 bulk solids, including chemical and pharmaceutical powders, fuels such as coal and coke, food products such as flour and sugar, ores such as copper and bauxite, and ultra low-density materials such as carbon black and fumed silica.
Ring Shear Tester for bulk solids testing
Wall friction test for bulk solids