Process and apparatus for producing and using cold ammonia

A method for carrying out the substantially adiabatic expansion of a pressurized stream of ambient-temperature liquid ammonia to produce a stream of cold liquid anhydrous ammonia at substantially ambient or atmospheric pressure and a stream of cold gaseous ammonia at substantially ambient or atmospheric pressure, which comprises (1) introducing a stream of ambient temperature, pressurized liquid ammonia at a pressure between about 80 and about 200 psig through a flow control valve tangentially into a cylinderical expansion chamber having a weight of less than about 100 pounds at a location on the chamber walls about midway from the top and bottom of the chamber, (2) imparting a high velocity spinning motion to the liquid ammonia entering the chamber such that rapid flow is produced around the interior circumference of the chamber to thereby provide rapid separation of the liquid and gaseous ammonia in the chamber, and wherein the chamber is provided with an outlet useful for the removal of cold liquid ammonia therefrom, said outlets being provided at opposite ends of said expansion chamber, (3) directing the flow of the cold substantially ambient or atmospheric pressure liquid ammonia from the chamber walls to said outlet useful for the withdrawal of cold ambient or atmospheric pressure liquid ammonia from said expansion chamber to effect separation between cold liquid ammonia and cold gaseous ammonia within said expansion chamber and (4) withdrawing through said outlet useful for the removal of gaseous ammonia a stream of cold gaseous ammonia at substantially ambient or atmospheric pressure and a stream of cold liquid ammonia at substantially ambient or atmospheric pressure via said other outlet.

Apparatus for carrying out the substantially adiabatic expansion of a pressurized stream of ambient-temperature liquid ammonia to produce a stream of cold liquid ammonia at substantially ambient or atmospheric pressure and a stream of cold gaseous ammonia at substantially ambient or atmospheric pressure, which comprises (1) means for introducing at a velocity of at least about 5000 feet per minute a stream of ambient-temperature, pressurized liquid ammonia into an axially elongated expansion chamber, (2) means for imparting a high velocity spinning motion to the liquid ammonia entering the chamber such that rapid flow is produced around the interior of the chamber to thereby provide rapid separation of the liquid and gaseous ammonia formed in the chamber, and wherein the expansion chamber is provided with (3) a first outlet means for the removal of gaseous ammonia therefrom which outlet means is located above the path of liquid flow and (4) a second outlet means useful for the removal of cold liquid ammonia therefrom, said first and second outlet means being provided at opposite ends of said expansion chamber, (5) means for directing the flow of the cold substantially ambient or atmospheric pressure liquid ammonia within said expansion chamber to said second outlet means to effect separation between cold liquid ammonia and cold gaseous ammonia within said expansion chamber, and (6) means for withdrawing through said first outlet means a stream of cold gaseous ammonia at substantially ambient or atmospheric pressure and (7) means for withdrawing a stream of cold liquid ammonia at substantially ambient or atmospheric pressure via said second outlet means.