Patent ID: 6200014
Filing Date: 2001-03-13
Classification: B01F,G05D

Abstract:
A mixer, for mixing a drag-reducing material with a liquid, said mixer comprising:a mixing chamber positioned in a flow path of said liquid;a rotatable member positioned upstream in said flow path from the mixing chamber;transfer means for conveying a drag-reducing material from a drag-reducing material source toward said mixing chamber, said transfer means delivering the drag-reducing material at a rate that is dependent on the liquid speed in the flow path, for liquid speeds above a given threshold, so that the drag-reducing material concentration after mixing with said liquid is substantially independent of the liquid speed in the flow path, wherein the transfer means includes an Archimedes screw within a housing, a first end of the housing being in communication with a supply of said drag-reducing material, said Archimedes screw being driven in rotation by rotation of said rotatable member to thereby convey a measured amount of drag-reducing material toward said mixing chamber for each rotation of said rotatable member.