Simplified architecture for desalination via electrodialysis

An electrodialysis desalination device, comprising:

• a first electrode including a first-stage side;
• a second electrode including a first-stage side;
• a first stage between the first-stage side of the first electrode and the first-stage side of the second electrode, the first stage including at least one first-stage cell pair positioned between the first-stage side of the first electrode and the first-stage side of the second electrode, each cell pair including a pair of first-stage selectively permeable ion-exchange membranes with alternating selectivity that define first-stage channels on opposite sides of each first-stage membrane for respective flows of a first-stage diluate stream and a first-stage concentrate stream between the first electrode and the second electrode, wherein each of the first-stage channels includes an inlet and an outlet;
• a second stage including at least one second-stage cell pair including a plurality of second-stage selectively permeable ion-exchange membranes with alternating selectivity that define second-stage channels on opposite sides of each second-stage membrane for respective flows of a second-stage diluate stream and a second-stage concentrate stream, wherein the outlet for the first-stage channel through which the first-stage diluate stream flows is in fluid communication with the inlet of the second-stage channel through which the second-stage diluate stream flows, and wherein the outlet for the first-stage channel through which the first-stage concentrate stream flows is in fluid communication with the inlet of the second-stage channel through which the second-stage concentrate stream flows;
• a single pump configured to pump the diluate streams and the concentrate streams through the first stage and through the second stage, wherein, in each stage, the concentrate stream has an increased ion content that is greater than the ion content of the diluate stream;
• and
• a plurality of flow restrictors in or in communication with a plurality of the channels selected from the first-stage channels and the second-stage channels through which the first-stage and second-stage diluate and concentrate streams respectively flow, wherein each of the flow restrictors is configured to receive at least one of the diluate or concentrate streams in one of the selected channels of the first stage or the second stage, and wherein the flow restrictors are configured in combination with the single pump to generate a flow rate of the diluate stream that is independent and distinct from a flow rate of the concentrate stream through the first-stage and second-stage channels.