A 2D2D-type cyclone inlet was substituted for the tall, narrow inlet of the
standard 1D3D cyclone to overcome choking problems when using the standard
flat-top inlet transition, or performance problems when using an inverted
transition. This inlet modification lowered the modified cyclone's emission
s by 8 to 9%, and slightly reduced its static pressure requirements. The 1D
3D cyclone equipped with a 2D2D inlet operated satisfactorily with either t
he standard 1D3D-type air outlet duct, or the shorter 2D2D-type outlet. The
size of the cyclone's trash exit significantly affected PM10 emissions. A
larger (D/3) size exit produced PM10 emissions that were about 8% lower tha
n those resulting from use of the standard, small-diameter (D/4) exit.