Powder and Bulk Technology Comparisons

Volumetric feeding meters material by feeder displacement over time, while gravimetric feeding measures mass flow and adjusts output from weight feedback.

Volumetric systems can be simpler when material condition and required accuracy are stable; gravimetric systems are generally preferred when mass accuracy, changing bulk density or documented feed-rate verification justifies the additional weighing, controls and commissioning work.

Choose between a vibratory sieve and a centrifugal sifter by defining the separation task and feed condition first.

A vibratory sieve presents powder to one or more screens using vibration and can support safety screening or grading, while a centrifugal sifter uses rotating paddles inside a cylindrical screen to move powder through the mesh in an enclosed inline arrangement.

Vacuum conveying is usually the stronger starting point when powder must be drawn from several pickup points to one receiver and inward air leakage is preferable at open interfaces.

Positive-pressure conveying is often considered when one source must feed several destinations or the route and duty demand a different pressure envelope.

Choose a rotary valve when continuous pocket discharge must also limit gas leakage across a pressure boundary; choose a screw feeder when controlled extraction from an elongated hopper outlet, wider turndown or positive solids transport is the governing duty.

Neither device is a universal explosion-isolation barrier.

Dilute phase conveying keeps particles suspended in a relatively large gas flow and is usually the more flexible choice for robust materials.

Dense phase conveying moves a higher concentration of solids at lower velocity and is often preferred when attrition, segregation, or pipeline wear must be limited.