The Johanson Indices

The Johanson Indices are derived from measured consolidation pressures, time at rest and atmospheric conditions that simulate a plant’s actual operating environment and test sample surfaces that simulate material handling equipment.

The Indices safely and accurately answer the most common material handling and equipment design questions including

• How large should the hopper outlet be?
• What hopper angle do I need?
• What happens to material inside a bin if I use vibrators or air cannons? Where do I place them?
• Do I need a hopper with flow at the walls? If so, what type?
• Can I use a partial mass-flow hopper?
• Do I need air injection to prevent limiting flow rate hangups?
• What chute angles do I need?