A reverse osmosis system includes a membrane unit, an energy recovery device, high and low pressure inlet lines, and a concentrate line. The membrane unit has a membrane, an inlet for receiving a feed fluid, a permeate outlet for discharging a permeate fluid and a concentrate outlet for discharging a concentrate fluid. The energy recovering device has a turbine portion, a turbine inlet and a turbine outlet, a pump portion, a pump inlet and a pump outlet, a motor, and a motor control unit for controlling the motor. The low pressure inlet line is connected to the pump inlet for supplying the feed fluid at a low pressure. The high pressure inlet line connects the pump outlet with the inlet for supplying the feed fluid at a high pressure. The concentrate line connects the concentrate outlet with the turbine inlet for supplying the concentrate fluid to the turbine portion.

Method and apparatus for batch and semi-batch operation of membrane system using a sweep stream with essentially repeating process flows is disclosed. The method and apparatus are used for separating a source liquid into its constituent solvents and solutes. The method includes circulating a feed stream and sweep stream in a feed side circulation loop and a sweep side circulation loop, respectively, in a counter-current, or co-current or cross-flow configuration. The pressure in the feed loop is gradually increased to initiate flow of solvent from the feed loop to the sweep loop. The concentrate and diluate streams obtained may be continuously removed. The applied feed loop pressure is continually increased until maximum desired operating pressure is reached or maximum concentration of a solute is reached in the feed solution. The method extends the maximum achievable salt concentration of RO process to at least about 300 g/L NaCl.

Method and apparatus for batch and semi-batch operation of membrane system using a sweep stream with essentially repeating process flows is disclosed. The method and apparatus are used for separating a source liquid into its constituent solvents and solutes. The method includes circulating a feed stream and sweep stream in a feed side circulation loop and a sweep side circulation loop, respectively, in a counter-current, or co-current or cross-flow configuration. The pressure in the feed loop is gradually increased to initiate flow of solvent from the feed loop to the sweep loop. The concentrate and diluate streams obtained may be continuously removed. The applied feed loop pressure is continually increased until maximum desired operating pressure is reached or maximum concentration of a solute is reached in the feed solution. The method extends the maximum achievable salt concentration of RO process to at least about 300 g/L NaCl.

A reverse osmosis system includes a first pretreatment system and a fluid source located below a reservoir. A first membrane housing has a reverse osmosis membrane therein. A first turbocharger includes a first pump portion and a first turbine portion. The first pump portion receives feed fluid from the first pretreatment system, pressurizing the feed fluid and communicates the feed fluid to the feed fluid inlet. The first turbine portion receives brine fluid from the brine outlet. The system further includes a second and third turbocharger. A second turbine portion and the third turbine portion receive brine fluid from the first turbine portion. Second feed fluid is communicated through a booster pump, a second pretreatment system, and second pump portion to increase a pressure of the second feed fluid. The second feed fluid is communicated to the third pump portion which communicates the pressurized second feed fluid to the first pump portion.

A reverse osmosis system includes a first pretreatment system and a fluid source located below a reservoir. A first membrane housing has a reverse osmosis membrane therein. A first turbocharger includes a first pump portion and a first turbine portion. The first pump portion receives feed fluid from the first pretreatment system, pressurizing the feed fluid and communicates the feed fluid to the feed fluid inlet. The first turbine portion receives brine fluid from the brine outlet. The system further includes a second and third turbocharger. A second turbine portion and the third turbine portion receive brine fluid from the first turbine portion. Second feed fluid is communicated through a booster pump, a second pretreatment system, and second pump portion to increase a pressure of the second feed fluid. The second feed fluid is communicated to the third pump portion which communicates the pressurized second feed fluid to the first pump portion.

The present invention discloses an SWRO and MCDI coupled seawater desalination device system with energy recovery, including a pre-filtering unit, an SWRO treatment unit, an MCDI treatment unit, and a post-filtering unit. The SWRO treatment unit is coupled with the MCDI treatment unit. Seawater desalination is performed through a coupling complementary water passage and circuit design, while water quality is improved, and the continuity of water output from a water passage of the device is kept. By recovering the pressure potential energy of high-pressure brine in the SWRO treatment unit and electric energy released by desorption in the MCDI treatment unit, energy consumption is reduced.

The present invention discloses an SWRO and MCDI coupled seawater desalination device system with energy recovery, including a pre-filtering unit, an SWRO treatment unit, an MCDI treatment unit, and a post-filtering unit. The SWRO treatment unit is coupled with the MCDI treatment unit. Seawater desalination is performed through a coupling complementary water passage and circuit design, while water quality is improved, and the continuity of water output from a water passage of the device is kept. By recovering the pressure potential energy of high-pressure brine in the SWRO treatment unit and electric energy released by desorption in the MCDI treatment unit, energy consumption is reduced.

A reverse osmosis system includes a membrane unit, an energy recovery device, high and low pressure inlet lines, and a concentrate line. The membrane unit has a membrane, an inlet for receiving a feed fluid, a permeate outlet for discharging a permeate fluid and a concentrate outlet for discharging a concentrate fluid. The energy recovering device has a turbine portion, a turbine inlet and a turbine outlet, a pump portion, a pump inlet and a pump outlet, a motor, and a motor control unit for controlling the motor. The low pressure inlet line is connected to the pump inlet for supplying the feed fluid at a low pressure. The high pressure inlet line connects the pump outlet with the inlet for supplying the feed fluid at a high pressure. The concentrate line connects the concentrate outlet with the turbine inlet for supplying the concentrate fluid to the turbine portion.

A reverse osmosis system includes a membrane unit, an energy recovery device, high and low pressure inlet lines, and a concentrate line. The membrane unit has a membrane, an inlet for receiving a feed fluid, a permeate outlet for discharging a permeate fluid and a concentrate outlet for discharging a concentrate fluid. The energy recovering device has a turbine portion, a turbine inlet and a turbine outlet, a pump portion, a pump inlet and a pump outlet, a motor, and a motor control unit for controlling the motor. The low pressure inlet line is connected to the pump inlet for supplying the feed fluid at a low pressure. The high pressure inlet line connects the pump outlet with the inlet for supplying the feed fluid at a high pressure. The concentrate line connects the concentrate outlet with the turbine inlet for supplying the concentrate fluid to the turbine portion.

A system and method of operating the same includes a membrane chamber comprising a membrane, an inlet, a concentrate outlet and a permeate outlet. The membrane chamber is located in a body of water at a predetermined depth. A turbocharger is disposed at about the predetermined depth and includes a pump portion coupled to the inlet of the membrane chamber and a turbine portion coupled to the concentrate outlet. A pump communicates pressurizing feed fluid and communicates the feed fluid to the turbine portion of the turbocharger though a feed pipe. A permeate pipe extends from the permeate outlet to about the surface of at the body of water.