Patent ID: 6381866
Filing Date: 2002-05-07
Classification: B01D,B01F,C08B,F26B

Abstract:
Continuous process for the drying and gel formation of solvent-containing gel-forming polymers, comprising polysaccharide derivatives, of hot, aqueous cellulose ether suspensions, by flash cooling of suspensions of the polymers, comprising the steps:metering the solvent-containing polymer having a solids content of 1 to 65% by weight, or of 5 to 50% by weight, or of 10 to 40% by weight, at a pressure of ambient pressure to 6000 hPa, at a polymer temperature of 20 to 100Â° C., or of 30 to 95Â° C., into an evaporation zone (1), comprising a paste bunker, the evaporation zone (1) having a pressure of 0.1 hPa to 800 hPa, or of 20 hPa to 700 hPa, or of 40 hPa to 200 hPa, cooling the polymer, to a temperature of <93Â° C., or <60Â° C., or of 60Â° C. to 29Â° C., freeing the polymer of 2 to 5% by weight of solvent with mechanical stirring, mixing and conveying of the mixture to the lower end of the evaporation zone (1) with formation of a dense gelled product layer discharging the polymer by means of a mechanical discharge apparatus (7), with the aid of a single-screw or multiscrew conveyor (7), with further densification of the polymer, and subsequently drying the gelled polymer in a drying apparatus to a solvent content of not more than 5% by weight.