US Patent 7828866 Dirt and dust cyclonic separating apparatus

A cyclonic separating apparatus includes a first cyclonic separating unit including at least one first cyclone, a second cyclonic separating unit located downstream of the first cyclonic separating unit and including at least one second cyclone, and a third cyclonic separating unit located downstream of the second cyclonic separating unit and including at least one third cyclone. The separation efficiency of the second cyclonic separating unit is substantially the same as the separation efficiency of either the first cyclonic separating unit or the third separating unit, providing an apparatus which achieves a higher separation efficiency than known separation apparatus.