Abstract: A method for producing a cellulose solution with a solvent from a cellulose suspension in the solvent and a volatile non-solvent, including the introduction of the suspension into an inlet of a thin-film treatment apparatus, application and distribution of the suspension in a film-like form on a housing casing, temperature-controlled using a heat exchanger, by sweeper elements rotating about a common axis in a process housing of the treatment apparatus, evaporation of volatile non-solvent so that the cellulose is dissolved, and output of the solution of cellulose from the treatment apparatus through an outlet, wherein at least a part of the sweeper elements cause the cellulose to be advanced in the direction of the outlet so that the discharge at the outlet is between 300 kg/h and 600 kg/h cellulose solution per m2 of the temperature-controlled surface of the housing casing.

Abstract: A thin-film treatment apparatus for treating viscous material includes a process housing oriented at an incline of at most 20° with a heatable and/or coolable housing casing, which surrounds a housing interior forming a material treatment space, an inlet nozzle arranged in an inlet zone of the process housing to introduce the material to be treated into the material treatment space, an outlet nozzle arranged in an outlet zone of the process housing to discharge the treated material from the material treatment space, and a drivable rotor shaft arranged in the material treatment space and extending coaxially for producing a material film on the inner surface of the housing casing and for conveying the material in the direction of an outlet zone. The rotor shaft includes at least one lift element arranged on the rotor shaft body, for producing a lifting force in the direction of the rotating rotor shaft body.