# US 12,180,096 B2 · Fluid purification methods, devices, and systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,180,096 B2 - Document ID: US12180096B2 - Status: Granted - Kind: B2 - Application number: 17/176,621 - Filed: 2021-02-16 - Published: 2021-06-03 - Granted: 2024-12-31 - Earliest claimed: 2011-12-13 - Assignees: NxStage Medical, Inc. - Applicants: NxStage Medical, Inc. - Inventors: Joseph E. Turk, Jr.; William K. Weigel; Goetz Friederichs; Jeffery B. Hover, Sr. - Web page: https://patentgrep.com/patent/US12180096B2 ## CPC - C02F 1/4695: {electrodeionisation} - B01D 61/428: {Membrane capacitive deionization} - B01D 61/54: Controlling or regulating - C02F 1/006: {Water distributors either inside a treatment tank or directing the water to several treatment tanks; Water treatment plants incorporating these distributors, with or without chemical or biological tanks (for settling tanks B01D21/24)} - C02F 1/008: {Control or steering systems not provided for elsewhere in subclass C02F} - C02F 1/32: with ultraviolet light - C02F 1/441: {by reverse osmosis} - C02F 1/444: {by ultrafiltration or microfiltration} - B01D 61/52: Accessories; Auxiliary operation - B01D 65/02: Membrane cleaning or sterilisation {; Membrane regeneration} - B01D 2317/02: Elements in series - B01D 2321/04: Backflushing - B01D 2321/12: Use of permeate - C02F 2201/46115: Electrolytic cell with membranes or diaphragms - C02F 2201/4613: Inversing polarity - C02F 2201/46145: Fluid flow - C02F 2209/003: Downstream control, i.e. outlet monitoring, e.g. to check the treating agents, such as halogens or ozone, leaving the process - C02F 2209/005: Processes using a programmable logic controller [PLC] - C02F 2209/40: Liquid flow rate - C02F 2301/08: Multistage treatments, e.g. repetition of the same process step under different conditions - C02F 2303/16: Regeneration of sorbents, filters - Y10T 137/8593: Systems - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A fluid purification system has cells whose purifying capability can be regenerated. Some of the cells are arranged in series to reach a high level of purification. An automatic valve network is controlled to cycle the cells in a way that levels the loads on each, thereby maximizing the service interval for replacing expired cells, enabling all of the cells to be replaced at the same time after having each contributing approximately equally to the purification load, and operated such that at any one time, at least one cell is regenerated so as to enable continuous up-time. ## Claims ### Claim 1 A fluid purification system, comprising: a controller; a first multi-stage purifier having a first inlet and a first outlet; a second multi-stage purifier having a second inlet and a second outlet, each of the first multi-stage purifier and the second multi-stage purifier having multiple cells connectable in a series between a respective inlet and a respective outlet for multi-stage purification of a fluid by an arrangement of controllable valves controlled by the controller; and a fluid circuit including the controllable valves and fluid lines, wherein the controller is configured to control the controllable valves to direct a flow of the fluid to be purified through the first multi-stage purifier, in a flow direction into the first inlet and out of the first outlet, while directing the flow of purified fluid exiting from the first outlet toward the second outlet of the second multi-stage purifier such that the purified fluid flows in a reverse direction through only a selected cell of the second multi-stage purifier and out of the second inlet of the second multi-stage purifier toward a drain, wherein the controller is further configured to control the controllable valves to direct the flow of the fluid to be purified through the second multi-stage purifier, in a flow direction into the second inlet and out of the second outlet of the second multi-stage purifier toward the first outlet of the first multi-stage purifier such that the purified fluid flows in a reverse direction through only a selected cell of the first multi-stage purifier and out of the first inlet toward the drain. ### Claim 2 (depends on 1) The system of claim 1, wherein when the controller controls the controllable valves to cause the flow from the respective inlet to the respective outlet of a respective one of the first and second multi-stage purifiers, the fluid flows through respective cells such that a cell that is most recently regenerated via reverse flow is last in the series of the cells and a cell that was the least recently regenerated is first in the series. ### Claim 3 (depends on 1) The system of claim 1, wherein the controller is configured to control the controllable valves such that the selected cell is a cell that is the least recently regenerated cell. ### Claim 4 (depends on 1) The system of claim 1, wherein flowing the purified fluid in the reverse direction through the selected cell is effective to regenerate the selected cell. ### Claim 5 (depends on 1) The system of claim 1, wherein the cells are electronic deionization cells. ### Claim 6 (depends on 1) The system of claim 1, wherein the controller is configured to apply a positive voltage to the cells through which the fluid flows in a forward direction and to apply a negative voltage to the cells through which the fluid flows in the reverse direction. ### Claim 7 (depends on 1) The system of claim 1, wherein cells in first multi-stage purifier and in the second multi-stage purifier are interconnected in series such as to produce a 99.9% reduction in total dissolved solids in the fluid. ### Claim 8 (depends on 1) The system of claim 1, wherein the fluid is water. ### Claim 9 A system for a fluid purification that is operable to purify a fluid after attachment of cells to the system, the system comprising: a controller; a fluid transport network with fluid channels; and valves controllable by the controller; the fluid transport network including a plurality of cell connectors configured to fluidly connect cells adapted for purifying the fluid and to direct a flow of the fluid in a forward direction or in a reverse direction through respective pairs of cell connectors; a plurality of cells, each cell of the plurality of cells connected by a pair of the cell connectors; and the fluid transport network having an inlet for receiving the fluid to be purified, a first outlet for outputting a purified product fluid, and a second outlet for outputting a waste fluid, wherein the controller is configured to operate the valves such that, at a first time, the fluid to be purified is directed from the inlet through a first group of cells connected along a flow path, in series, such that multiple purification stages are defined, the first group of cells forming a series along the flow path that includes a first series cell being in a first position of the series and receiving the fluid to be purified, the fluid to be purified passing through the first series cell in the forward direction, a last series cell being in a last position of the series and outputting the purified product fluid, in the forward direction, and intermediate series cells between the first series cell and the last series cell receiving intermediate fluid in the forward direction, the controller is further configured to operate the valves such that, at the first time, the purified product fluid is directed in the reverse direction through a second series cell of the first group of cells whereby simultaneous multi-stage purification and cell regeneration are performed, the controller is further configured to operate the valves to rearrange the flow path of the first group of cells by replacing the last series cell with the second series cell and replacing the second series cell with the first series cell, the controller is further configured to operate the valves such that, at a second time, the fluid is directed in the reverse direction through the second series cell, which was the first series cell at the first time, and wherein rearrangement of the flow path of the cells in the series is accomplished without disconnecting any of the cells from any of the cell connectors. ### Claim 10 (depends on 9) The system of claim 9, wherein the controller is configured to apply a reverse voltage to the second series cell and apply a forward voltage to the first series cell. ### Claim 11 (depends on 9) The system of claim 9, wherein the fluid is water. ### Claim 12 (depends on 9) The system of claim 9, wherein the fluid transport network has water channels. ### Claim 13 (depends on 9) The system of claim 9, wherein the cell connectors are adapted for receiving electronic deionization cells. ### Claim 14 (depends on 9) The system of claim 9, wherein the first group of cells, at the first time, are at least three in number having the first series cell, the last series cell and intermediate cells ordered by rank in the series, and the intermediate cells, at the second time, are moved forward in rank so that the first series cell is replaced by the intermediate cell of a lowest rank. ### Claim 15 (depends on 14) The system of claim 14, wherein the controller is configured to operate the valves such that each of the cells is repositioned successively through the series, taking a turn at each rank at respective times and taking a turn as the second series cell to be regenerated.