Flow Properties

Why Flow Properties Testing?

A thorough understanding of a bulk material’s flow properties and its flowability are crucial for identifying the cause of poor flow, powder flooding or rate limitations, segregation, or product non-uniformity.  Flow properties tests are also critical when designing a new silo/bin/hopper, stockpile, feeder, chute, conveyor or other material handling equipment.  Issues can arise or be compounded when powder and bulk solids flow properties have not been measured, the test results may be limited, or the data are non-representative of the application.

Flow Properties Tests

Key bulk material flow properties that should be measured for troubleshooting problems, assessing powder flowability, or designing a bulk material handling system are:

  • Cohesive strength:  powder flowability through hoppers
  • Wall friction:  hopper angles to achieve Mass flow
  • Internal friction:  static and kinematic angles of internal friction
  • Compressibility:  bulk density as a function of major consolidating pressure
  • Permeability:  gas/solids interactions; limiting discharge rates from hoppers
  • Angle of repose:  angle of pile of material at rest
  • Loose/tap density:  bulk density measured before and after vibration
  • Chute:  chute angles required to maintain flow after impact

When testing for bulk material flow properties, it is vital to replicate actual or expected process conditions.

Test variables: Available range

  • Time at rest:  continuous flow to weeks of storage at rest
  • Pressure:  low (pharmaceutical) to high (stockpiles)
  • Temperature:  14° to 2,200° F (-14° to 1,200° C)
  • Humidity:  90% to less than 5% relative humidity
  • Atmosphere:  air, inert, and a range of process gases

Test Results

The flow properties test results are presented in a comprehensive report containing:

  • an executive summary of results
  • graphical and tabular presentation of data
  • appendix with terminology definitions

We will also have one of our engineers review the report with you to ensure understanding of the test results and their common use in bulk material handling applications.

Need to send samples for testing?  Click here for additional information.

What’s Next

Contact us to review your specific bulk material testing needs and our world-class testing capabilities.  Or, explore our typical project approach, which highlights our key engineering services driven by your unique project requirements.

Jenike & Johanson experienced engineers are available to show you how to effectively use your powder and bulk solids flow properties and maximize your project investment.