| 摘要 |
PURPOSE: Provided are a continuous process for the drying and gel formation of solvent-containing gel-forming polymers, in particular polysaccharide derivatives, by flash cooling of suspensions of the polymers and an apparatus for the drying of solvent-containing products. CONSTITUTION: The continuous process for the drying and gel formation of solvent-containing gel-forming polymers, in particular polysaccharide derivatives, particularly preferably 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, preferably of 5 to 50% by weight, particularly preferably of 10 to 40% by weight, at a pressure of in particular ambient pressure to 6000 hPa, at a polymer temperature of 20 to 100 deg.C, preferably of 30 to 95 deg.C, into an evaporation zone(1), preferably a paste bunker, the evaporation zone(1) having a pressure of 0.1 hPa to 800 hPa, preferably of 20 hPa to 700 hPa, particularly preferably of 40 hPa to 200 hPa, cooling the polymer, in particular to a temperature of less than 93 deg.C., in particular less than 60 deg.C, especially of 60 deg.C to 29 deg.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, in particular with the aid of a single-screw or multiscrew conveyor(7), optionally 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.
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