DEEP CLEANING METHOD OF COOLANT R717 Russian patent published in 2019 - IPC C01C1/00 B01D53/02 

FIELD: technological processes.

SUBSTANCE: invention relates to methods of purifying substances and relates to the development of a method for deep purification of R717 (ammonia) coolant used in two-phase thermal control systems of large-size structures of spacecrafts. Method of deep purification of R717 involves rectification of technical ammonia in a periodic packed column with a middle feed tank. Process is carried out in a mode of parallel sampling of higher boiling and low-boiling impurity fractions relative to coolant R717 from the lower and upper sampling points until achieving the required purity of coolant R717 in the middle feed tank, wherein the process is carried out at absolute pressure in a column in range of 10 to 40 bar and temperature of 25 to 60 °C, wherein the column load is maintained at least 70 % of the limit pressure at the pressure and temperature of the process. Working pressure in the column is maintained in range of 30–40 bar at removal of impurities with high liquid-vapor ratio and in range of 10–20 bar at removal of impurities with low liquid-vapor ratio.

EFFECT: increased efficiency and reduced power consumption of the cleaning process with simultaneous increase of the separation effect in the column, which increases the degree of product separation and the cleaning depth.

1 cl, 3 ex