Patent ID: 7695614
Filing Date: 2010-04-13
Classification: B01D,C02F,Y02A

Abstract:
1. An apparatus for continuous closed-circuit consecutive sequential desalination of a salt water solution by reverse osmosis without using containers, the apparatus comprising: at least one closed circuit unit comprising: one desalination module, the desalination module comprising one or more membrane elements, an inlet, a permeate outlet and a concentrate outlet, or two or more of the desalination modules having their respective inlets and outlets connected in parallel; and a concentrate circulating line connecting between the concentrate outlet and the inlet of said one desalination module or between the concentrate outlets and the inlets of said two or more desalination modules; a feed line for supplying fresh feed of salt water solution to said at least one closed circuit unit through a feed inlet; at least one pressurizing device in said feed line for pressurizing said fresh feed of salt water solution into said at least one closed circuit unit and for creating sufficient counter pressure in said closed circuit unit to enable reverse osmosis desalination and replacement of released permeate by fresh feed; at least one circulation system in said concentrate circulating line for recycling pressurized concentrate from the concentrate outlet to the inlet of said one desalination module or from the concentrate outlets to the inlets of the two or more desalination modules; at least one permeate collection conducting line for collecting permeate from said closed circuit unit; at least one brine effluent conducting line for removing brine effluent from said closed circuit unit; at least one valve system in said concentrate circulating line configured to direct concentrate flow to either circulate in said closed circuit unit or to said at least one brine effluent conducting line, wherein said valve system is located upstream and in close proximity to the feed inlet to enable periodic discharge of brine from said closed circuit unit without stopping desalination; a monitoring means for monitoring progress of desalination in said at least one closed circuit unit; and a control system coupled to said monitoring means and to said at least one valve system to enable continuous closed circuit desalination of desired recovery proceed in consecutive sequential steps under variable or constant pressure conditions by alternately diverting concentrate flow between a concentrate recycling mode and a concentrate discharge mode without stopping desalination.