Ammonia distillation

Claim 1

THE METHOD OF CONCENTRATING A WEAK AQUEOUS SOLUTION OF AMMONIA TO PRODUCE ANHYDROUS AMMONIA BY FRACTIONATION, WHEREIN THERE IS AVAILABLE STEAM AT A PRESSURE BELOW 245 P.S.I.G. AND COOLING WATER AT A TEMPERATUARE OF FROM 60*F. TO 100*F. WHICH COMPRISES STEAM STRIPPING AND RECTIFYING SAID SOLUTION IN A FIRST COLUMN AT A PRESSURE EXCEEDING ATMOSPHERIC BUT LESS THAN THE PRESSURE OF SAID AVAILABLE STEAM THEREBY PRODUCING AN AMMONIA-FREE BOTTOMS AND AN AQUEOUS AMMONIA OVERHEAD IN SAID COLUMN, TOTALLY CONDENSING SAID OVERHEAD WITH COOLING WATER AT SAID TEMPERATURE, RECYCLING A PORTION OF SAID CONDENSATE AS A REFLUX TO SAID FIRST COLUMN, INCREASING THE PRESSURE ON A SECOND PORTION OF SAID CONDENSATE, DISTILLING SAID SECOND PORTION OF SAID CONDENSATE UNDER SAID INCREASED PRESSURE IN A SECOND COLUMN THEREBY PRODUCING AN ANHYDROUS AMMONIA OVERHEAD AND A DILUTE AMMONIA BOTTOMS, CONDENSING SAID OVERHEAD WITH COOLING WATER AT SAID TEMPERATURE AND RECYCLING THE BOTTOMS FROM SAID SECOND COLUMN TO AN INTERMEDIATE POINT OF SAID FIRST COLUMN, THE MINIMUM PRESSURE IN SAID FIRST COLUMN INCREASING SUBSTANTIALLY LINEARLY FROM ATMOSPHERIC PRESSURE TO 30 P.S.I.G. AND THE PRESSURE IN SAID SECOND COLUMN INCREASING SUBSTATNTIALLY LINEARLY FROM 115 P.S.I.G. TO 235 P.S.I.G. BOTH IN ACCORDANCE WITH AN INDEPENDENT LINEAR VARIATION IN THE TEMPERATURE OF SAID AVAILABLE COOLING WATER FROM 60* TO 100*F.

Claim 2

THE METHOD OF CONCENTRATING A WEAK AQUEOUS SOLUTION OF AMMONIA TO PRODUCE ANHYDROUS AMMONIA BY FRACTIONATION, WHEREIN THERE IS AVAILABLE STEAM AT A PRESSURE BELOW 245 P.S.I.G. AND COOLING WATER AT A TEMPERATUARE OF FROM 60*F. TO 100*F. WHICH COMPRISES STEAM STRIPPING AND RECTIFYING SAID SOLUTION IN A FIRST COLUMN AT A PRESSURE EXCEEDING ATMOSPHERIC BUT LESS THAN THE PRESSURE OF SAID AVAILABLE STEAM THEREBY PRODUCING AN AMMONIA-FREE BOTTOMS AND AN AQUEOUS AMMONIA OVERHEAD IN SAID COLUMN, TOTALLY CONDENSING SAID OVERHEAD WITH COOLING WATER AT SAID TEMPERATURE, RECYCLING A PORTION OF SAID CONDENSATE AS A REFLUX TO SAID FIRST COLUMN, INCREASING THE PRESSURE ON A SECOND PORTION OF SAID CONDENSATE, DISTILLING SAID SECOND PORTION OF SAID CONDENSATE UNDER SAID INCREASED PRESSURE IN A SECOND COLUMN THEREBY PRODUCING AN ANHYDROUS AMMONIA OVERHEAD AND A DILUTE AMMONIA BOTTOMS, CONDENSING SAID OVERHEAD WITH COOLING WATER AT SAID TEMPERATURE AND RECYCLING THE BOTTOMS FROM SAID SECOND COLUMN TO AN INTERMEDIATE POINT OF SAID FIRST COLUMN, THE MINIMUM PRESSURE IN SAID FIRST COLUMN INCREASING SUBSTANTIALLY LINEARLY FROM ATMOSPHERIC PRESSURE TO 30 P.S.I.G. AND THE PRESSURE IN SAID SECOND COLUMN INCREASING SUBSTATNTIALLY LINEARLY FROM 115 P.S.I.G. TO 235 P.S.I.G. BOTH IN ACCORDANCE WITH AN INDEPENDENT LINEAR VARIATION IN THE TEMPERATURE OF SAID AVAILABLE COOLING WATER FROM 60* TO 100*F.