Patent ID: 11890578
Assignee: THE UNIVERSITY OF BIRMINGHAM
Field: Chemical engineering (Chemistry)
Classification: CPC B  C  F  Y | IPC B  C  F

Claim 15:
16. A method of operating a desalination system, the desalination system comprising:
a partitioned container housing a movable partition partitioning the container into an upstream compartment and a downstream compartment each of variable volume, the partitioned container having a first inlet port at an upstream end of the container, a second inlet port at a downstream end of the container and an outlet port at the downstream end of the container;
a membrane container housing a cross-flow semipermeable membrane dividing the membrane container into a saline compartment and a desalinated water compartment, the saline compartment comprising first and second cross-flow ports, the desalinated water compartment comprising a desalinated water outlet port;
a feed pump connected to feed a supply of saline water to the first inlet port;
a recharge pump connected between the second cross-flow port and the second inlet port to feed saline water into the downstream compartment;
a main valve connected between the outlet port and the first cross-flow port;
a bypass valve connected on one side to the first inlet port and on another side to the second cross-flow port and the recharge pump; and
a purge valve connected on one side to the first cross-flow port and the main valve and on another side to a purge port,
the method comprising:
in a first pressurisation stage, closing the bypass valve and purge valve, opening the main valve and operating the feed pump to provide a supply of saline water to the upstream compartment of the partitioned container, causing the partition to move and thereby flowing saline water from the downstream compartment into the saline compartment of the membrane container, thereby causing desalinated water to exit from the desalinated water compartment of the membrane container via the desalinated water outlet port; and
in a second recharge stage, opening the bypass valve and purge valve, closing the main valve and operating the recharge pump and feed pump to feed saline water to the second inlet of the partitioned container, into the saline compartment of the membrane container via the second cross-flow port and out through the purge port via the first cross-flow port.