The efficiency of a cyclone is best described using the concept of "cut diameter" d_c (particle diameter at which 50% of particles are removed).

The centrifugal force on particulates is given by:

f_CENT = mv²/r..................................................(7)

m= MASS OF PARTICLES
v= VELOCITY OF PARTICLES
r= RADIUS OF PATH (APPROXIMATELY RADIUS OF CYCLONE)

Thus collection efficiency increases with decreasing collector radius.

A "bank" of cyclones, in parallel can thus be used more effectively than a single large cyclone with the same "footprint" and throughput.

However we need to consider the fact that such multiple cyclones exibit greater clogging problems

Collection sizes for cyclones:

• Single-15-50 µm.
• Multiple-5-20 µm.

Unlike settling chambers the cyclone becomes more efficient at high loading