Powder and Bulk Technology Comparisons

Choose volumetric feeding when material condition is stable and verified output at a set speed meets your acceptance criteria — it meters by displacement over time and is the simpler system.

Choose gravimetric feeding when mass accuracy, changing bulk density or documented feed-rate verification justifies the added weighing, controls and commissioning work, because it corrects output from weight feedback.

Neither machine wins by default.

A vibratory sieve presents powder to one or more vibrating screens and supports safety screening or grading; a centrifugal sifter uses rotating paddles inside a cylindrical screen for enclosed inline sifting or deagglomeration.

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 comes into play 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.

Dilute phase conveying suspends particles in a relatively large gas flow at higher velocity 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.