Dilute-Phase Conveying

Dilute-phase pneumatic conveying moves dry bulk material through pipe by suspending it in a high-velocity air stream. The material-to-air ratio is low — typically 1:5 to 1:15 by weight — and the material moves at roughly the same velocity as the conveying air, between 4,000 and 7,000 feet per minute. Dilute-phase is the more common of the two pneumatic conveying modes (the other is dense-phase). It's used for materials that are tolerant of high velocity, including plastic pellets, cement, fly ash, sand, sugar, and grain. Wear-part selection in dilute-phase systems is dominated by impact wear — the material hits the outside radius of every turn at high speed. Ceramic-backed elbows are the dominant wear solution in this regime.