These conveying technologies are differentiated by three basic criteria. They are conveying velocity, operating pressure and material to air ratio (MAR). Material to air ratio is the mass relationship of product to air (normally pound per pound) in the conveying system.
|
Conveying Modes |
Operating Pressure |
Pick-up Velocity |
Terminal Velocity |
Material to Air Ratio |
|
Dilute Phase |
Up to 18 psig
(Up to 1.22 bar) |
3000-5000 ft./min.
(15-25 M/S) |
More than 6000 ft/min
(More than 25 M/S) |
Up to 22:1 |
|
Medium Phase |
15-35 psig
(1.02 – 2.38 bar) |
1800 – 3500 ft./min.
(9 – 18 M/S) |
3000-5000 ft./min.
(15 – 25 M/S) |
15:1 – 30:1 |
|
Dense Phase |
30-65 psig
(2.04 – 4.42 bar) |
400-1800 ft./min.
(2.5 – 9 M/S) |
Less than 4000 ft./min.
(Less than 20 M/S) |
25:1 – 200:1 |