METHOD AND UNIT FOR SOLAR DESALINATION WITH MULTISTAGE DISTILLATION AND ZERO BRINE DISCHARGE Russian patent published in 2023 - IPC C02F1/14 

FIELD: chemistry.

SUBSTANCE: invention relates to desalination of sea or subsaline water to obtain demineralized water and salt and can be used in countries with a hot climate with the availability of salt (for example, sea) water resources and a shortage of drinking water. The method includes concentrating solar energy on the outer surface of the first-stage steam generator producing steam under pressure from salt water supplied to it under pressure, supplying steam under pressure to a multi-stage modular evaporator plant, at each stage of which heating steam is condensed and secondary steam is formed from salt water. The resulting steam from one stage becomes the heating steam for the next stage when condensed. Concentrate removal and steam condensate removal from the evaporator stages is provided. The generation of pressurized steam and secondary steam is carried out on the inner surface of horizontal film evaporation drums (FEDs) partially filled with salt water. The rotation of FEDs ensures the rolling of the scraper elements under the salt water level, which clean the heating surface from salt deposits. The pressure inside the drums makes it possible, after reaching a predetermined salt content, to periodically withdraw the concentrate from the drums to a horizontal sun-heated pan. Hot condensate is supplied to the pan jacket from the evaporator modules of the stages and the vapor-condensate mixture is supplied from the last stage of the multistage modular evaporator plant. The concentrate is dried to a state of dry salt, and the condensate is drained into a container for demineralized water.

EFFECT: ease of maintenance, minimization of salt deposits on heating surfaces, high degree of water purification from salts, production of a commercial product in the form of dry salt.

8 cl, 3 dwg, 1 tbl