Vertical multistage distillation apparatus

Claim 1

DISTILLATION APPARATUS COMRISING A VESSEL, PARTITIONS IN SAID VESSEL DIVIDING IT INTO A SERIES OF DISTILLATION COMPARTMENTS DISPOSED ONE ABOVE THE OTHER, WITH EACH SUCCEEDING COMPARTMENT MAINTAINED AT A LOWER PRESSURE THAN THE LOWER ONE PRECEDING IT, SAID PARTITIONS PROVIDING HEAT TRANSFER SURFACES BETWEEN THE COMPARTMENTS, LIQUID FLOWCONTROLLING MEANS FEEDING A MOVING FILM OF LIQUID TO BE EVAPORATED ONTO A FIRST SURFACE OF EACH OF SAID PARTITIONS, AND DISTILLATE-COLLECTING MEANS DISPOSED TO RECEIVE DISTILLATE CONDENSING ON A SECOND SURFACE OF EACH OF SAID PARTITIONS AT THE OPPOSITE SIDE OF SAID PARTITION TO SAID FIRST SURFACE, SAID FIRST AND SECOND SURFACES OF EACH PARTITION CONSTITUTING RESPECTIVE BOUNDING WALLS OF TWO CONSECUTINVE COMPARTMENTS IN THE SERIES OF WHICH TWO CONSECUTIE COMPARTMENTS THAT WHICH IS BOUNDED BY SAID FIRST SURFACE IS MAINTAINED AT A LOWE PRESSURE THAN THAT WHICH IS BOUNDED BY SAID SECOND SURFACE, VAPOR GENERATED IN EACH COMPARTMENT EXCEPT THE BOTTOM, FROM THE LIQUID FILM ON SAID FIRST SURFACE OF THE RESPECTIVE PARTITION WHOSE FIRST SURFACE BOUNDS SAID COMPARTMENT, TRAVERSING THE COMPARTMENT AND CONDENSING ON SAID SECOND SURFACE OF THE NEXT PARTITION IN SERIES THEREBY TO EVAPORATE LIQUID AT A LOWER PRESSURE FROM THE FILM ON SAID FIRST SURFACE OF SAID NEXT PARTITION IN THE NEXT UPPER COMPARTMENT AND MEANS FOR HEATING THE FIRST SURFACE OF THE LOWERMOST PARTITION.