Modular multiple-effect falling-film evaporator

Claim 1

THE MODULAR MULTIPLE-EFFECT FALLING-FILM EVAPORATOR WHICH COMPRISSES; AN ELONGATE INSULATED UNITARY PRESSURE VESSEL HAVING SIDEWALLS, FRONT AND REAR ENDWALLS, A BOTTOM AND A TOP; AT LEAST TWO FIRST TRANSVERSE VERTICAL PARTIAL PARTITION WALLS ARRANGED IN LONGITUDINALLY-SPACED RELATION TO THE VESSEL ENDWALLS AND TO ONE ANOTHER, SAID PARTITION WALLS TERMINATING IN SPACED RELATION BENEATH THE TOP OF THE VESSEL WHILE EXTENDING ALL THE WAY TO THE BOTTOM THEREOF, AND SAID PARTITION WALLS COOPERATING WITH THE ADJOINING VESSEL WALLS TO DIVIDE THE LOWER PORTION OF THE LATTER INTO A PLURALITY OF LIQUID-TIGHT COMPARTMENTS ARRANGED IN END-TO-END RELATION AND ADAPTED TO RECEIVE PROGRESSIVELY RICHER CONCENTRATED LIQUORS BEGINNING AT THE FRONT END; A SECOND TRANSVERSE VERTICAL PARTIAL PARTITION WALL CORRESPONDING TO EACH OF THE FIRST PARTIAL PARTITION WALLS POSITIONED IN LONGITUDINALLY SPACED RELATION THEREBEHIND, EACH OF SAID SECOND PARTITION WALLS EXTENDING FROM THE TOP OF THE VESSEL TO A LEVEL CONSIDERABLY BELOW THE UPPER MARGIN OF THE ADJACENT FIRST PARTITION WALL; A VERTICAL LONGITUDINAL PARTITION WALL BRIDGING THE SPACE BETWEEN EACH SET OF ADJACENT FIRST AND SECOND PARTITION WALLS; AHORIZONTAL LONGITUDINAL PARTITION ALL JOINED TO THE VERTICAL LONGITUDINAL PARTITION WALL AND BRIDGING THE GAP BETWEEN EACH SET OF ADJACENT FIRST AND SECOND PARTITION WALLS IN SPACED RELATION BENEAATH THE TOP EDGES THEREOF AND SPACED ABOVE THE BOTTOM OF THE VESSEL, SAID VERTICAL AND LONGITUDINAL PARTITION WALLS COOPERATING WITH ONE ANOTHER, THE ADJACENT VESSEL WALLS AND SAID FIRST AND SECOND PARTITION WALLS TO COMPARTMENTALIZE THE SPACE BETWEEN THE LATTER INTO AN OPEN-TOPPED LIQUID-TIGHT FLASH TANK AND AN OPEN-TOPPED LIQUID-TIGHT CONDENSATE TANK ARRANGED IN SIDE-BY-SIDE RELATION, AND SAID HORIZONTAL PARTITION WALL FURTHER COOPERATING WITH THE ADJOINING WALL MEMBERS TO SEAL OFF THE INTEROR OF THE VESSEL INTO A PLURALITY OF SEPARATE VAPOR COMPARTMENTS ADAPTED TO RECEIVE HOT CONDENSABLE PROCESSING VAPORS GENERATED IN THE PRECEDING VAPOR COMPARTMENT NEARER THE FRONT END OF SAID VESSEL AND MAINTAIN SAME AT A SLIGHTLY REDUCED PRESSURE; MEANS COMPRISING ENCLOSED CONCENTRATED LIQUOR RESERVOIRS MOUNTED IN THE TOP OF THE VESSEL IN SPACED RELATION ABOVE EACH OF THE CONDENSATE TANKS SEALED OFF FROM THE VAPOR CONPARTMENTS THEREBENEATH; MEANS INCLUDING A PUMP CONNECTED TO WITHDRAW THE CONCENTRATED LIQUORS FROM EACH COMPARTMENT EXCEPT THE LAST AND DELIVER SAME TO THE CONCENTRATED LIQUOR RESERVOIR OF THE SUBSEQUENT EFFECT; MEANS COMPRISING A PLURALITY OF OPEN-ENDED EVAPORATOR TUBES ARRANGED IN VERTICALLY-DISPOSED SPACED PARALLEL RELATION TO ONE ANOTHER MOUNTED WITHIN EACH VAPOR COMPARTMENT IN THE PATH OF HOT PROCESSING VAPORS PASSING OVER THE TOP OF THE ADJACENT FIRST PARTIAL PARTITION WALL AND DOWN INTO THE CONDENSATE TANK, THE UPPER OPEN ENDS OF THE TUBES BEING FASTENED IN LIQUID-TIGHT SEALED RELATION WITHIN THE CORRESPONDING CONCENTRATED LIQUOR RESERVOIR IN POSITION TO CONTINUOUSLY RECEIVE CONCENTRATED LIQUORS THEREFROM AND ALLOW SAME TO GRAVITATE DOWN THE INSIDE THEREOF, AND THE LOWER OPEN ENDS OF SAID TUBES BEING CONNECTED THROUGH THE HORIZONTAL LONGITUDINAL WALL MEMBER IN LIQUID-TIGHT SEALED RELATION THERETO SO AS TO DELIVER THE HOT PROCESSING VAPORS GENERATED THERIN ALONG WITH THE MORE HIGHLY-CONCENTRATED LIQUOR FRACTION DIRECTLY INTO THE SUBSEQUENT CONCENTRATED LIQUOR COMPARTMENT AND NEXT LOWER-PRESSURED VAPOR COMPARTMENT; MEANS CONNECTABLE TO A SOURCE OF LIQUID EVAPORTATABLE FEED ADAPTED TO PREHEAT SAME PRIOR TO INTRODUCTION THEREOF INTO THE CONCENTRATED LIQUOR RESERVOIR OF THE HIGHEST-PRESSURED CHAMBER, SAID MEANS INCLUDING AT LEAST TWO SERIALLY-INTERCONNECTED MULTIPLE-PASS HEAT EXCHANGERS MOUNTED VERTICALLY WITHIN ADJACENT VAPOR CAMPARTMENTS IN POSITION TO EXTEND DOWNWARDLY INTO THE CONDENSATE TANK ALONGSIDE THE EVAPORATOR TUBES, THE COLDER FEED ENTERING THE HEAT EXCHANGER NEAREST THE REAR END OF THE PRESSURE VESSEL AND FLOWING THEREFROM THROUGH THE REMAINDER OF SAID HEAT EXCHANGERS IN COUNTER-CURRENT FLOW RELATION TO THE FLOW OF HOT PROCESSING VAPORS, AND THE PRE-WARMED FEED ENTERING THE FIRST OF THE CONCENTRATED LIQUOR RESERVOIRS BEING TAKEN FROM THE HEAT EXCHANGER LOCATED NEAREST THE FRONT END OF THE PRESSURE VESSEL; MEANS CONNECTED INTO THE INTEROR OF THE CONDENSATE TANK OF THE HIGHEST-PRESSURE VAPOR COMPARTMENT ADAPTED TO WITHDRAW VAPORS CONDENSING OUT OF THE EVAPORATOR TUBES THEREIN AND DELIVER SAME TO THE FLASH TANK WITHIN THE NEXT LOWERPRESSURED VAPOR COMPARTMENT; MEANS OPENING INTO THE INTERIOR OF EACH OF THE REMAINING CONDENSTE TANKS ADAPTED TO RECEIVE THE VAPORS CONDENSING ON THE OUTSIDE SURFACES OF THE RESPECTIVE EVAPORATOR AND HEAT EXCHANGER TUBES THEREIN AND PASS SAME TO THE FLASH TANK ALONGSIDE THEREOF; MEANS CONNECTED TO WITHDRAW THE CONDENSATE FROM THE LAST-MENTIONED FLASH TANK WITHIN EACH VAPOR COMPARTMENT EXCEPT THE LOWEST-PRESSURED ONE AND DELIVER SAME TO THE FLASH TANK IN THE NEXT LOWER-PRESSURED VAPOR COMPARTMENT WHERE A PORTION THEREOF VAPORIZES AND JOINS THE VAPORS GENERATED WITHIN THE EVAPORATOR TUBES; VENTED MEANS CONNECTED TO RECEIVE THE NON-CONDENSABLE GASES FROM EACH OF THE VAPOR COMPARTMENTS AND VENT SAME; MEANS CONNECTED INTO THE INTERIOR OF THE HIGHEST-PRESSURED VAPOR COMPARTMENT AND CONNECTABLE TO A SOURCE OF HOT PROCESSING VAPORS ADAPTED TO INTRODUCE THE LATTER UNDER PRESSURE; CONDENSING MEANS CONNECTED INTO THE INTERIOR OF THE LOWEST-PRESSURED VAPOR COMPARTMENT ADAPTED TO WITHDRAW THE CONDENSABLE VAPORS THEREFROM AND CONDENSE SAME; MEANS CONNECTED TO WITHDRAW CONDENSATE FROM THE FLASH TANK OF THE LOWESTPRESSURED COMPARTMENT; AND MEANS CONNECTED TO WITHDRAW THE CONCENTRATED LIQUOR FROM THE CONCENTRATED LIQUOR COMPARTMENT IN THE LOWEST-PRESSURED VAPOR COMPARTMENT.