Learning About Cyclones

:: Section 7

Collection Efficiency

I. Lapple's Model

The first theory was developed by Lapple. It's based on the assumption of a plug flow (i.e. laminar flow with no axial or radial mixing). In order to calculate the efficiency, first the particle size with 50% collection efficiency (dp_50%) as the baseline needs to be determined, according to the following equation:

where μ is viscosity of air, b is inlet width, N_e is the number of effective turns (number of turns the flow makes from the entrance to the midpoint of the core section), V_i is inlet velocity and ρ_p is particle density. The collection efficiency (the ratio of the collected fraction to the total at the inlet) for any other size, d_pj, can then be determined by