Using Fundamental Properties to Optimize Powder Flowability was published in Tablets & Capsules and explains how formulators can use shear cell and permeability test results to ensure that their blends will reliably flow in bins and hoppers.
Using Solids Flow Properties to Design Mass- and Funnel-Flow Hoppers was published in Powder and Bulk Solids. It's similar to the T&C article, but it includes a funnel flow bin example.
URI Notes is an up-to-date pdf of my book Storage and Flow of Bulk Solids, and I update it regular.y for clarity, brevity, and levity. I use it in the powder handling course that I give at the University of Rhode Island. It requires a password to open because I offer the textbook on my home page. An abridged version of my book does not require a password. You can also download the Excel workbooks that I use to design bins or predict flow behavior in existing bins.
The concepts are straightforward, but the analysis can be painful because the equations are serpentine, and the calculations are iterative. The compressed file named Hopper Design Files contains the Excel files that I use to analyze shear cell and permeability test results to predict powder flow behavior or design bins. The hopper design workbook has some nice VBA-driven macros that walk the user through Jenike's methods. The regression workbook can be used to regress shear cell and permeability test data to determine the parameters used in the hopper design workbook. To design a hopper or predict powder flow behavior, you only need the following computer skills: CTRL+C and CTRL+V. Easy as π !
I modified Jerry Johanson's solids discharge rate equation so that it can be used with fine powders and compared what it predicts to some published powder discharge rate data. I was pleasantly surprised! It's included in my spreadsheets, and if you want to see the derivation, download Maximum Steady Discharge Rates from Hoppers.
I solved Andrew Jenike's solids velocity equations (Solids Velocity Profiles in Hoppers). I can't believe that Jenike was able to solve them without a computer!
I periodically add other documents on powder handling and processing. Be sure to visit and check for updates.