Occurs when the material is conveyed at a velocity above the saltation velocity (minimum conveying/suspension velocity) of the material. In this type of system the material is “suspended” in the conveying air stream and typically requires pick-up conveying air velocities of 3,200 to 7,000 feet per minute. Dilute phase systems typically operate at positive pressures of 5-12 PSIG or negative pressures of 4-12” Hg with solids to air ratios (pounds of product per pound of air) of less than 12:1. This type of conveying system is typically utilized to convey materials that are not susceptible to degradation or are not abrasive in nature.
