Hydrocyclone

Claim 2

A cyclone separator for separating the impurities from a suspension of acceptable fibers comprising in combination a vessel having an elongated vertical axis and being of substantially circular cross section and having an upper inlet chamber for receiving the suspension charged under pressure tangentially thereinto and a lower inverted conical vortex chamber communicating with the inlet chamber for receiving the suspension therefrom and inducing a downward spiral flow in a free vortex path outwardly of a transition zone extending generally parallel to the vertical axis of the vessel toward the lower end of the conical vortex chamber. A discharge opening for the discharge therethrough of the reject fraction of the suspension from the lower end of the conical vortex chamber, a vortex finder disposed concentrically of the inlet chamber and having an inlet end within and substantially coaxial with the vessel and having an opposite discharge end outwardly of the vessel for inducing a reversal of the downward flow of the accepted fraction of the suspension from the free vortex path at the lower end of the conical vortex chamber to an inner forced vortex path inwardly of the transition zone and circumscribing a formed central air core, a contactable and expandible flow restrictor disposed within and transversely of the vortex finder for selectively extending into the forced vortex low path a variable degree and accordingly shifting the transition zone laterally of the vertical axis of the vessel.