Conveying Air Velocity

For dilute phase conveying a relatively high value of conveying air velocity must
be maintained. This is typically in the region of 2400 ft/min for a very fine powder,
to 3200 ft/min for a fine granular material, and beyond for larger particles and
higher density materials. For dense phase conveying, air velocities can be down to
600 ft/min, and lower in certain circumstances. Because of the fine particle size
required to provide the necessary air retention, particle density does not have such
a significant effect on the minimum value of conveying air velocity in moving bed
type dense phase conveying.