:: Section 7
Pressure Drop and Power
Since impaction relies on the flow velocity, a higher efficiency is the result of a higher flow velocity. However, a higher flow velocity is accompanied by a higher pressure drop across the system that can be translated into cost as a more powerful fan is required. The pressure drop can be determined by:
where ρg is density of gas and NH is number of gas inlet velocity head. The pressure drop for a general purpose, a medium efficiency or a high efficiency cyclone is typically 2-4, 4-8 and 8-10 inch H2O, respectively. The power requirement (Wf) can then be determined according to:
The total cost is related to the power as
where TC is total cost and $ is unit electricity cost.