Pneumatic conveying "Lean Phase"

The Lean Phase pneumatic conveying system allows moving powdery and granular materials over a more or less long distance using low pressure air compressed (< 1 bar) and high conveying velocity (20 to 25 m/s). This conveying mode is chiefly used for non-explosive, non-abrasive powdery materials.

Material conveying is continuously processed. Material enters the pipeline through a rotary valve via an injecting device or directly (blowing valve).

Compressed air is made by a blower or a fan.

In lean phase pneumatic conveying, two principles can be used :

• The positive pressure systems (blowing) an,
• The negative pressure systems (suction).

The choice between these two systems depends on the materials physical characteristics and the desired conveying flowrates.

Material to air ratio is very important and often requires setting up of more or less large size filters with fans on hoppers or collecting silos

A principal advantages of this method are :

• Relatively small amount of investment,
• Easy implementation,
• Ability to have multiple feed points for a single circuit.