Multi-Stage Reverse Osmosis Systems and Methods
AssigneeMassachusetts Institute of Technology
InventorsQuantum J. Wei, Ronan Killian McGovern, John H. Lienhard, V
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AssigneeMassachusetts Institute of Technology
InventorsQuantum J. Wei, Ronan Killian McGovern, John H. Lienhard, V
Estimating the term…
Improved reverse osmosis (RO) systems include at least first and second stages wherein each stage has at least one RO membrane, each stage has a feed stream inlet, a permeate stream outlet, and a concentrate stream outlet, the feed stream inlet of the second stage is coupled to the concentrate stream outlet of the first stage, the second pressure is greater than the first pressure, and pressure exchangers associated with each of the first and second stages are configured to recover energy from the second stage concentrate stream. The systems include M reverse osmosis membranes in the first stage and N reverse osmosis membranes in the second stage, wherein M≧N. The first pressure and second pressure are configured so that spatial variance in flux of the first stage permeate stream relative to flux of the second stage permeate stream is minimized.
An improved reverse osmosis separation system, having at least first and second stages, of a type wherein (i) each stage has at least one reverse osmosis membrane, (ii) each stage has a feed stream inlet for a feed stream, a permeate stream outlet for a permeate stream, and a concentrate stream outlet for a concentrate stream, (iii) the feed stream inlet of the second stage is coupled to the concentrate stream outlet of the first stage, (iv) the feed stream entering the first stage is pressurized to a first pressure and the feed stream entering the second stage is pressurized to a second pressure, (v) the second pressure is greater than the first pressure, and (vi) pressure exchangers associated with each of the first and second stages are configured to recover energy from the second stage concentrate stream, wherein the improvement comprises:
An improved method of operating a reverse osmosis separation system, having at least first and second stages, of a type wherein (i) each stage has at least one reverse osmosis membrane, (ii) each stage has a feed stream inlet for a feed stream, a permeate stream outlet for a permeate stream, and a concentrate stream outlet for a concentrate stream, (iii) the feed stream inlet of the second stage is coupled to the concentrate stream outlet of the first stage, (iv) the feed stream entering the first stage is pressurized to a first pressure and the feed stream entering the second stage is pressurized to a second pressure, (v) the second pressure is greater than the first pressure, and (vi) pressure exchangers associated with each of the first and second stages are configured to recover energy from the second stage concentrate stream, wherein the improvement comprises:
Dependencies are inferred from the claim text.