Improved low temperature absorption refrigeration

Claim 1

A METHOD FOR PROVIDING REFRIGERATION WHICH COMPRISES FLASHING LIQUID AMMONIA IN SUCCESSIVELY LOWER PRESSURE FLASHING STEPS TO COOL THE UNVAPORIZED AMMONIA TO DESIRED REFRIGERATION TEMPERATURES, ABSORBING THE FLASHED AMMONIA IN AQUEOUS AMMONIA OF PROGRESSIVELY INCREASED CONCENTRATIONS OF AMMONIA IN PROGRESSIVELY HIGHER TEMPERATURE AND PRESSURE ABSORPTION STEPS, PASSING THE FINALLY PRODUCED AQUEOUS AMMONIA INTO A FRACTIONATION COLUMN AND THEREIN FRACTIONATING SAID AQUEOUS AMMONIA UNDER SUPERATMOSPHERIC PRESSURE TO PRODUCE AN OVERHEAD VAPOROUS AMMONIA PRODUCT AND A BOTTOMS PRODUCT OF AQUEOUS AMMONIA MORE DILUTE THAN THE AQUEOUS AMMONIA PASSED INTO THE COLUMN AS FEED, CONDENSING SAID OVERHEAD VAPOROUS AMMONIA TO PRODUCE LIQUID AMMONIA, REDUCING THE PRESSURE ON THE AQUEOUS AMMONIA BOTTOMS PRODUCT IN A BOTTOMS FLASHING OPERATION, REMOVING FLASH VAPORS OF AQUEOUS AMMONIA FROM THIS BOTTOMS FLASHING OPERATION AND PASSING SAME INTO THE ABSORPTION STEP OF HIGHEST PRESSURE AND TEMPERATURE OF THE SUCCESSIVE ABSORPTION STEPS, COOLING THE FLASH BOTTOMS OF SAID BOTTOMS FLASHING OPERATION IN INDIRECT HEAT EXCHANGE WITH THE AQUEOUS AMMONIA FEED TO SAID COLUMN, PASSING THE COOLED FLASH BOTTOMS OF SAID BOTTOMS FLASHING OPERATION INTO THE ABSORPTION STEP OF LOWEST PRESSURE AND TEMPERATURE OF THE SUCCESSIVE ABSORPTION STEPS, COOLING THE AQUEOUS AMMONIA AND VAPOROUS AMMONIA OF THE HIGHEST PRESSURE ABSORPTION STEP BY INDIRECT HEAT EXCHANGE WITH PLANT COOLING WATER AND COOLING THE AQUEOUS AMMONIA AND VAPOROUS AMMONIA OF THE LOWEST PRESSURE ABSORPTION STEP BY INDIRECT HEAT EXCHANGE WITH THE CONDENSED LIQUID AMMONIA.

Claim 2

A METHOD FOR PROVIDING REFRIGERATION WHICH COMPRISES FLASHING LIQUID AMMONIA IN SUCCESSIVELY LOWER PRESSURE FLASHING STEPS TO COOL THE UNVAPORIZED AMMONIA TO DESIRED REFRIGERATION TEMPERATURES, ABSORBING THE FLASHED AMMONIA IN AQUEOUS AMMONIA OF PROGRESSIVELY INCREASED CONCENTRATIONS OF AMMONIA IN PROGRESSIVELY HIGHER TEMPERATURE AND PRESSURE ABSORPTION STEPS, PASSING THE FINALLY PRODUCED AQUEOUS AMMONIA INTO A FRACTIONATION COLUMN AND THEREIN FRACTIONATING SAID AQUEOUS AMMONIA UNDER SUPERATMOSPHERIC PRESSURE TO PRODUCE AN OVERHEAD VAPOROUS AMMONIA PRODUCT AND A BOTTOMS PRODUCT OF AQUEOUS AMMONIA MORE DILUTE THAN THE AQUEOUS AMMONIA PASSED INTO THE COLUMN AS FEED, CONDENSING SAID OVERHEAD VAPOROUS AMMONIA TO PRODUCE LIQUID AMMONIA, REDUCING THE PRESSURE ON THE AQUEOUS AMMONIA BOTTOMS PRODUCT IN A BOTTOMS FLASHING OPERATION, REMOVING FLASH VAPORS OF AQUEOUS AMMONIA FROM THIS BOTTOMS FLASHING OPERATION AND PASSING SAME INTO THE ABSORPTION STEP OF HIGHEST PRESSURE AND TEMPERATURE OF THE SUCCESSIVE ABSORPTION STEPS, COOLING THE FLASH BOTTOMS OF SAID BOTTOMS FLASHING OPERATION IN INDIRECT HEAT EXCHANGE WITH THE AQUEOUS AMMONIA FEED TO SAID COLUMN, PASSING THE COOLED FLASH BOTTOMS OF SAID BOTTOMS FLASHING OPERATION INTO THE ABSORPTION STEP OF LOWEST PRESSURE AND TEMPERATURE OF THE SUCCESSIVE ABSORPTION STEPS, COOLING THE AQUEOUS AMMONIA AND VAPOROUS AMMONIA OF THE HIGHEST PRESSURE ABSORPTION STEP BY INDIRECT HEAT EXCHANGE WITH PLANT COOLING WATER AND COOLING THE AQUEOUS AMMONIA AND VAPOROUS AMMONIA OF THE LOWEST PRESSURE ABSORPTION STEP BY INDIRECT HEAT EXCHANGE WITH THE CONDENSED LIQUID AMMONIA.