Bulk Material Flow Testing | Powder Flow Testing

Overview

Why Flow Properties Testing?

Flow property testing is an essential step in designing processes and equipment for the specific characteristics of the material being handled.

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 is non-representative of the application.

Our lab has years of experience testing difficult to handle materials at moisture contents close to saturation.

Precision shear testing equipment can be brought on-site for testing of materials taken directly from production.

Shear testing of a powder that had caked over time at rest.

On-site material testing for samples that degrade with shipment, have process conditions that are difficult to replicate, or for unique containment requirements.

Approach

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

Results

Flow Property 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?

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