Patent attributes
A submersible reverse osmosis desalination apparatus and method employs airlift to remove desalinated water from the apparatus via as annular flow regime over a substantial portion of the product water discharge conduit. Use of a high air fraction for airlift operation and an annular flow regime significantly lowers the weight of the product water column, as well as the backpressure on the downstream side of the osmotic membranes and at the bottom of the discharge water conduit. This permits deployment of the apparatus at reduced depths and in many eases closer to shore. In preferred embodiments the apparatus relies wholly upon hydrostatic pressure to drive seawater through the osmotic membranes, and continuously desalinates seawater and delivers pure water to the discharge water conduit without using any submerged moving parts subject to wear or breakage.
