Patent ID: 7434696

Claim:
An inlet head for a cyclone, comprising: an inlet head including a feed chamber therein having an inner side wall, a top wall at one end of the inner side wall, an open end at the other end of the side wall opposite said top wall, the open end being of circular cross-section with a central axis, an inlet port adjacent the top wall for delivering material to be separated to the feed chamber, the inlet port having a feed height dimension H 1 in the direction of the central axis, an overflow outlet in the top wall which is coaxial with the central axis, and a vortex finder at the top wall extending into the feed chamber in the direction of the central axis a distance L 1 from the top end wall; a feed inlet zone in the inner side wall of the feed chamber having an upstream end adjacent the inlet port and a downstream end extending away from said inlet port in a direction away from the top end wall, the feed inlet zone being defined by a volute having a volute axis extending around the inner side wall and including a first sector in which the volute is generally at right angles to the central axis and a second sector in which the volute extends around the side wall away from the top end wall and generally in the direction of the central axis a distance D; wherein the distance from the volute axis to the central axis decreases with the progression of the volute around the inner side wall in a direction away from the inlet port; and wherein the distance L 1 is a fraction F of the feed height dimension H 1 .