The secondary air flow enters from the top of the cyclone and moves downward toward the bottom, intercepting the particulate from the primary air.
The secondary air flow also allows the collector to optionally be mounted horizontally, because it pushes the particulate toward the collection area, and does not rely solely on gravity to perform this function.
A cyclonic separation is a method of removing particulates from an air, gas or liquid stream, without the use of filters, through vortex separation.
When removing particulate matter from liquid, a hydrocyclone is used; while from gas, a gas cyclone is used.
Similar separators are used in the oil refining industry (e.g.
for Fluid catalytic cracking) to achieve fast separation of the catalyst particles from the reacting gases and vapors.
An alternative cyclone design uses a secondary air flow within the cyclone to keep the collected particles from striking the walls, to protect them from abrasion.
The primary air flow containing the particulates enters from the bottom of the cyclone and is forced into spiral rotation by stationary spinner vanes.
Particles larger than the cut point will be removed with a greater efficiency, and smaller particles with a lower efficiency as they separate with more difficulty or can be subject to re-entrainment when the air vortex reverses direction to move in direction of the outlet Airflow diagram for Aerodyne cyclone in horizontal position, an alternate design.
Secondary air flow is injected to reduce wall abrasion, and to help move collected particulates to hopper for extraction.