Patent FR-2918364-B1 (FR)
Inventor: LOPEZ FERNAND
IPC: B01D61/02
Filed: 2007-07-03
Granted: 2009-10-02
Abstract: The device for purifying sea water, comprises a pair of modules for filtration of seawater immersed in the marine medium, and a low pressure cylinder block comprising pressurizing valves with multiple sides and low pressure chambers. The filtration modules (10a, 10b) are connected to each other by a motorized transmission to move the modules according to alternative movements of plunging and rising in the marine medium in phase opposition. Each filtration module comprises a high pressure chamber equipped with an inlet for selective admission of sea water to be filtered inside the chamber. The device for purifying sea water, comprises a pair of modules for filtration of seawater immersed in the marine medium, and a low pressure cylinder block comprising pressurizing valves with multiple sides and low pressure chambers. The filtration modules (10a, 10b) are connected to each other by a motorized transmission to move the modules according to alternative movements of plunging and rising in the marine medium in phase opposition. Each filtration module comprises a high pressure chamber equipped with an inlet for selective admission of sea water to be filtered inside the chamber, a semi-permeable membrane for filtering sea water by reverse osmosis, an outlet for recollecting filtered water produced by each membrane contained in the chamber, an outlet for evacuation of salt concentrated seawater and pressurizing valves optionally moved in the chamber rotating along a longitudinal axis for determining a pressure of seawater at the inlet of each membrane. The multiple sides of the valves comprise receiving sides linked to pressurizing sides of the valves to move longitudinally. The receiving sides of the valves are arranged to be subjected to a hydrostatic pressure of the marine medium, and are associated with atmospheric gas tight chamber. The total usage area combined of different receiving sides of the valves has a value greater than the usage area of the pressurizing sides with which receiving sides are linked. A volume of each low-pressure chamber varies along the same direction as the high pressure chamber movement of the receiving and pressurizing sides of the valves. The low pressure cylinder block has an overall transversal dimension less than or equal to the overall transversal dimension of the filtration module with respect to the longitudinal axis. The filtration module delimits the high pressure chamber comprising the pressurizing sides. The different receiving sides of the valves connected to the pressurizing sides of the valves are horizontally directed parallel to the longitudinal axis of the high pressure chamber, are parallel to each other and to the pressurizing sides of the valves, and are orthogonal to the longitudinal axis of the high pressure chamber. The different receiving sides of the valves are fixed to each other to have a total transversal dimension less than the sum of transversal dimension of each receiving side of the valve. The different receiving sides connected to the same pressurizing sides of the valves are superimposed on each other in the longitudinal direction of axis of the high pressure chamber so that the transversal dimension of all receiving sides is equivalent to one of receiving sides. The receiving side and low-pressure side of the pressurizing valves are two opposite parallel sides of the same valves, which are directed horizontally for forming sealing in a cylinder to define the low pressure chamber. The low pressure chambers of filtration modules are connected to each other by a pipe, which balances pressure between the low pressure chambers without pressure drop. Each filtration module is suspended in the marine medium by a suspension cable from the motorized transmission. The longitudinal axis of each pressurizing side and corresponding receiving sides are vertical. The suspension cable is coupled to the valve, which delimits the low pressure chamber. Each low pressure chamber extends over the high pressure chamber. The motorized transmission is suitable for movement of each filtration module between the surface of the marine medium and a maximum depth of 10-30 m, and comprises a renewable energy source chosen from a wind pump and a panel of photovoltaic light sensor. A ratio of usage area of each receiving side on usage area of the pressurizing side is 20-60.