High cyclone veolcities will causes excessive erosion; leading to a shorter operating campaign length.
Erosion increases to the 4th power of velocity.
The most typical aress fpr erosion occur in the inlet sweep areas, the cross-over duct (for 2-stage cyclones)
and the dust-bowl to dipleg transition area.
Once the excessive erosion breaches the refractory, the metal shell/skin is not far behind
and catalyst losses begin to increase.
