WATER DISTILLATION METHOD (OPTIONS) Russian patent published in 2018 - IPC C02F9/08 C02F1/42 C02F1/44 B01D61/12 C02F103/04 

FIELD: technological processes.

SUBSTANCE: inventions can be used to produce drinking water and for use in technological processes as a result of distillation or partial desalination of brackish and fresh water, mainly for artesian waters with increased rigidity. Method includes preliminary clarification of the initial water, feeding to Na-cationite filters, while the hardness of the softened water is set within the range of 0.02–0.1 mg-equ/l. Then, a solution of hydrochloric acid in an equivalent amount to sodium bicarbonate is dosed into the softened water. In the calciner, free carbonic acid is recovered from the water and sent to the reverse osmosis desalination stage, at least two-stage through the working concentrate line. At the first stage, the ratio of the initial flow to the working concentrate is set within 70–75 % and the working concentrate is directed to the second stage. After the second stage, the working concentrate is used as the feed water for the third stage. Operating pressure of the reverse osmosis desalination process is increased from the first stage to the last from 10 to 50 bar. Working concentrate after the last stage is sent to the tank-salt-solvent, in which the common salt is added. Salt content for regeneration of the Na-filter of the volume of the working concentrate after the last stage is set in the range of 30–50 g/l. Regenerative brine is pumped through the cation exchanger from the bottom to the top, with the spent regeneration solution draining after the filter for disposal.

EFFECT: methods provide an increase in the specific yield of permeate from the reverse osmosis desalination system, a reduction in the consumption of the concentrate over the desalination steps and, accordingly, a decrease in water consumption for the plant's own needs to 2,5–6 %.

10 cl, 2 dwg, 18 tbl, 2 ex