Multiple effect evaporator apparatus

Claim 1

A MULTIPLE EFFECT EVAPORATOR APPARATUS WHICH COMPRISES: A PLURALITY OF EVAPORATOR CHAMBERS DISPOSED IN VERTICAL ALINGMENT, A PLURALITY OF TIN FALLING INTERNAL FILM TYPE VERTICALLY ORIENTTED HEAT EXCHANGE TUBE BUNDLES FOR INCREASING EVAPORATION COEFFICIENT IN EACH OF SAID EVAPORATOR CHAMBERS, SAID HEAT EXCHANGE TUBES BEING MOLDED TO AN UPPER PLATE AT THE TOP ENDS AND TO A BOTTOM PLATE AT THE LOWER ENDS THEREOF, A VESSEL FOR RECEIVING SOLUTION PLACED ABOVE SAID UPPER PLATE IN EACH OF SAID CHAMBER, PRESSURE DIFFERENCE MAINTAINING MEANS FOR MAINTAINING DIFFERENCE OF PRESSURE BETWEEN SAID EVAPORATOR CHAMBERS IN THE SOLUTION FLOW PATH, A SIPHON OVERFLOW TUBE HAVING ONE END THEREOF CONNECTED TO AN OVERFLOW OUTLET OF SAID VESSEL ABOVE SAID PRESSURE DIFFERENCE MAINTAINING MEANS AT A PLACE CONTROLLING THE DEPTH OF SAID SOLUTION IN SAID VESSEL AND BEING OPEN TO THE CHAMBER CONTAINING SAID VESSEL, AND THE OTHER END OF SAID TUBE BEING CONNECTED TO THE BOTTOM PLATE ABOVE THE VESSEL IN THE NEXT LOWER EVAPORATOR CHAMBER AS AN OUTLET OF SAID SOLUTION FROM SAID OVERFLOW TUBE TO SAID LOWER VESSEL SO AS TO MAINTAIN THE PRESSURE DIFFERENCE BETWEEN THE UPPER AND LOWER CHAMBERS, WHEREBY AN OVERFLOW FROM SAID VESSEL OVER ITS BRIM TO SAID BOTTOM PLATE OF ITS CONDENSING CHAMBER IS PREVENTED SO AS TO PREVENT CONTAMINATION OF THE RESULTING CONDENSATE WITH SAID SOLUTION, AND SAID OVERFLOW TUBE RECEIVING SAID SOLUTION UNDER A DIFFERENTIAL HEAD SO AS TO OVERFLOW SAID SOLUTION, REGARDLESS OF THE PRESSURE DIFFERENCE IN EACH CHAMBER.