EVAPORATOR WITH ASCENDING AND DESCENDING FILMS Russian patent published in 2003 - IPC

FIELD: tubular film-type evaporators; chemical, food-processing, microbiological and other industries. SUBSTANCE: proposed evaporator includes vertical housing with branch pipes for inlet and outlet of solution, heating steam and condensate and heat-exchange tubes secured in tube sheets. Novelty of invention consists in availability of two heat-exchange tubes with ascending film and two tubs with descending film; located inside tubes is pull rope with ball members fitted on it; they are locked by elastic tubes. Mounted in upper part of heat-exchange tube for ascending motion of film is syrup discharge unit made from cylinder to whose lower portion truncated cone is secured; lesser base of said cone is fixed on upper end part of heat- exchange tube; elastic membrane secured in upper part of cylinder has hole whose diameter is lesser than diameter of ball member used for cleaning from syrup. Mounted in upper part of heat-exchange tubes for descending motion of film is staring solution inlet unit which is made in form of truncated cone whose lesser diameter is directed towards end part of heat-exchange tube. Mounted in lower part of heat-exchange tube for descending motion of film is syrup discharge unit made in form of cylinder with elastic membranes secured in its lower part; said membrane has coaxial hole whose diameter is lesser than diameter of ball member. Proposed evaporator ensures smooth thickness of film over height of heat-exchange tubes reducing time required for performing the process and degree of contamination of inner surfaces due to elastic membrane. EFFECT: enhanced efficiency. 8 dwg