Abstract
A long-body return flow cyclone with a large value of cyclone characteristic factor √Ai/D0 has a tendency to increase both the pressure loss and the collection efficiency in the range of ReD≅2700-4000 of Reynolds number based on the cyclone diameter.
In a normal cyclone, the downward spiral flow becomes an upward return flow at the end of the conical part of the cyclone, but the long-body cyclone with an asymetrical spiral flow shows an unsteady flow. The outside downward flow changes into an upward flow at the length of h*/D0≅3.5-4 from the cyclone inlet, and the spiral flow does not reach to the bottom end of the long-body cyclone.
