Patent ID: 7670456

Claim:
A method for producing purified water using a multi-effect falling-film evaporation process, said method comprising the steps of: a) introducing a feed water into an inner wall of an evaporation tube in a first evaporation effect and plant steam to an exterior of said evaporation tube in said first evaporation effect, said plant steam heating said evaporation tube and said feed water disposed in said evaporation tube to produce steam and residual water from said feed water; b) flowing said residual water in a first conduit and flowing said steam in a second conduit, separate from said first conduit; c) supplying said residual water produced in said evaporation effect into an inner wall of an evaporation tube in a subsequent evaporation effect; d) removing a fraction of said steam produced from said feed water from said evaporation effect as a reject stream by flowing said steam through a spiral channel to remove said fraction of said steam therefrom and flowing said fraction of said steam to an isolated compartment and removing said reject stream from said isolated compartment by flowing said reject stream in a third conduit; e) supplying a remainder of said steam produced from said feed water through a fourth conduit to an exterior of said subsequent evaporation tube in said subsequent evaporation effect, wherein said steam heats said evaporation tube and said feed water disposed in said evaporation tube in said subsequent evaporation effect to produce steam and residual water; and f) repeating steps b)-e) for each subsequent evaporation effect.