Patent ID: 7121714

Claim:
A mixer comprising: an elongate hollow body having a peripheral wall surrounding a hollow interior providing a fluid flow passage; a fluid flow inlet for admission of a fluid and a material to be mixed with that fluid into one end of the fluid flow passage; a fluid flow outlet for outlet of the mixture from the other end of the fluid flow passage; a series of openings formed in the peripheral wall of the hollow body; an outer sleeve closely fitted about and extending along the peripheral wall of the hollow body so as to cover all of said openings and to close the fluid flow passage against flow of fluid to or from the fluid flow passage through the openings; drive means operable to impart relative motion between the elongate hollow body and the closely fitted sleeve such that there is relative movement between the openings and the peripheral wall of the hollow body and those parts of the sleeve covering the openings in directions across the openings to create viscous drag on the fluid flowing within the fluid flow passage generating transverse peripheral flows of fluid within that passage simultaneously in the vicinity of all of the openings.