Desalination brine concentration system and method

A brine concentration system, comprising:

• a nano-filtration unit;
• a first reverse osmosis membrane unit;
• a second reverse osmosis membrane unit;
• a first hollow fine fiber unit;
• a second hollow fine fiber unit;
• and
• a third hollow fine fiber unit,
• wherein
• the nano-filtration unit is configured to receive a saline source stream at a retentate side of the nano-filtration unit,
• the first reverse osmosis membrane unit is configured to receive a nano-filtration unit permeate stream from the nano filtration unit at a retentate side of the first reverse osmosis membrane unit,
• the first hollow fine fiber unit is configured to receive a first portion of a nano filtration unit retentate stream from the nano filtration unit at a shell side of the first hollow fine fiber unit and a second portion of the nano filtration unit retentate stream at a bore side of the first hollow fine fiber unit, the first and second portions of the nano filtration unit retentate stream being proportioned to prevent a differential pressure between the shell side and the bore side of the first hollow fine fiber unit from exceeding a first predetermined differential pressure limit,
• the first hollow fine fiber unit is configured to discharge a first hollow fine fiber retentate stream in the form of a first concentrated product,
• the first reverse osmosis membrane unit is configured to receive a first hollow fine fiber permeate stream from the first hollow fine fiber unit at the retentate side of the first reverse osmosis membrane,
• the second reverse osmosis membrane unit is configured to receive a first reverse osmosis membrane unit retentate stream at a retentate side of the second reverse osmosis membrane unit and to produce a second reverse osmosis permeate stream,
• the second hollow fine fiber unit is configured to receive a first portion of a second reverse osmosis membrane unit retentate stream from the second reverse osmosis membrane unit at a shell side of the second hollow fine fiber unit and a second portion of the second reverse osmosis membrane unit retentate stream at a bore side of the second hollow fine fiber unit, the first and second portions of the second reverse osmosis membrane unit retentate stream being proportioned to prevent a differential pressure between the shell side and the bore side of the second hollow fine fiber unit from exceeding a second predetermined differential pressure limit,
• the first reverse osmosis membrane unit is configured to receive a second hollow fine fiber unit permeate stream at the retentate side of the first reverse osmosis membrane unit,
• the third hollow fine fiber unit is configured to receive a first portion of a second hollow fine fiber unit retentate stream from the second hollow fine fiber unit at a shell side of the third hollow fine fiber unit and a second portion of the second hollow fine fiber unit retentate stream at a bore side of the third hollow fine fiber unit, the first and second portions of the second hollow fine fiber unit retentate stream being proportioned to prevent a differential pressure between the shell side and the bore side of the third hollow fine fiber unit from exceeding a third predetermined differential pressure limit,
• the third hollow fine fiber unit is configured to discharge a second hollow fine fiber retentate stream in the form of a second concentrated product, and
• the second reverse osmosis membrane unit is configured to receive a third hollow fine fiber permeate stream at the retentate side of the second reverse osmosis membrane unit, and
• the first reverse osmosis membrane unit is configured to produce a first reverse osmosis permeate stream from the nano-filtration unit permeate stream, the first hollow fine fiber permeate stream, and the second hollow fine fiber permeate stream.