What is low pressure drop cyclones and why is it called ?as you find mostly drafts (Negative Pr )in cyclones and not pressure(PositivePr) in cyclones.So they should be called as low draft cyclones.

Low pressure drop cyclone have pressure drop across cyclone is around 50 mmwg.High pressure drop cyclone have pressure drop around 75mmwg across cyclone.Generally low pressure drop cyclone have larger diameter then the high pressure drop cyclone.In preheater all pressure should be in negative only. Regards, R.M.Sahu, India

Draft is negative pressure. There is a change in pressure across a cyclone and that change in pressure is referred to as the pressure drop, i.e. there is a more negative pressure at the outlet than the inlet. In a cement kiln negative pressure must be maintained on the rotary section of the kiln. This is achieved by the induced draft fan. The higher the pressure drop across the preheater (each of the cyclones) the bigger must that fan be to maintain negative pressure in the kiln. So low pressure drop cyclones allow a smaller fan to be used for drafting the kiln, or allow additional clinker production with an existing fan.