Climbing and falling film evaporator with intermediate separation

Claim 1

IN AN EVAPORATOR, A STEAM CHEST HAVING A CENTRAL PORTION OF GENERALLY VERTICAL CYLINDRICAL FORM AND CYLINDRICAL AXIAL EXTENSIONS OF REDUCED DIAMETER AT OPPOSITE ENDS THEREOF, AN ANNULAR TUBE SHEET AT EACH END OF SAID CENTRAL PORTION CONNECTING THE LATTER WITH SAID CYLINDRICAL EXTENSIONS, AND A TUBE SHEET AT THE OUTER END OF EACH OF SAID EXTENSIONS, A GROUP OF TUBES EXTENDING BETWEEN THE LATTER TUBE SHEETS, AND A SECOND GROUP OF TUBES EXTENDING BETWEEN SAID ANNULAR TUBE SHEETS, LIQUOR INLET MEANS AT THE LOWER END OF SAID FIRST GROUP OF TUBES, A RECEIVING CHAMBER IN COMMUNICATION WITH THE UPPER ENDS OF BOTH GROUPS OF TUBES, AN ENTRAINMENT SEPARATOR ASSOCIATED WITH SAID RECEIVING CHAMBER FOR MOVING VAPOR ISSUING FROM SAID FIRST GROUP OF TUBES, THE UNVAPORIZED LIQUOR ISSUING FROM SAID FIRST GROUP OF TUBES GRAVITATING TO THE UPPER ENDS OF SAID SECOND GROUP OF TUBES, A RECEIVING CHAMBER AT THE LOWER END OF SAID STEAM CHEST IN COMMUNICATION WITH THE LOWER END OF SAID SECOND GROUP OF TUBES, AND AN ENTRAINMENT SEPARATOR ASSOCIATED WITH SAID LAST MENTIONED RECEIVING CHAMBER FOR REMOVING VAPOR ISSUING FROM THE LOWER ENDS OF SAID SECOND GROUP OF TUBES FROM UNVAPORIZED RESIDUAL LIQUOR.