Patent ID: 7115187

Claim:
A method for the continuous preparation of a suspension of cellulose in an aqueous tertiary amine oxide for use in the Lyocell process, the method comprising: (a) mixing cellulose and an amine oxide-free aqueous phase to form a cellulose suspension in a mass ratio in the range of 1:3 to 1:40, (b) dehydrating the cellulose suspension, wherein the dehydrated cellulose suspension has a cellulose content in the range of 20 to 80 percent-by-mass; (c) mixing the cellulose suspension with an aqueous amine oxide, wherein the aqueous amine oxide is injected into the cellulose suspension while the cellulose suspension is falling through a vertical fall zone that is only partially filled by the cellulose suspension, wherein enough aqueous amine oxide is mixed with the cellulose suspension to obtain an aqueous amine oxide-cellulose suspension with an amine oxide content in the range of 70 to 80 percent-by-mass; and (d) conveying the aqueous amine oxide-cellulose suspension through a horizontal shear zone so that the aqueous amine oxide-cellulose suspension fills the available cross-sectional conveyance area in the shear zone essentially completely.