Fluid purification methods, devices, and systems

• US 10,189,728 B2
• Filed: 07/19/2016
• Issued: 01/29/2019
• Est. Priority Date: 12/13/2011
• Status: Active Grant

• Current Assignee: Nxstage Medical Incorporated (Fresenius SE & Co. KGaA)
• Original Assignee: Nxstage Medical Incorporated (Fresenius SE & Co. KGaA)
• Inventors: Turk, Joseph, Weigel, William K., Friederichs, Goetz, Hover, Jeffery B.
• Primary Examiner(s): Zalasky, Katherine
• Application Number:
  US15/214,438
• Publication Number:
  US 20160340214A1
• Time in Patent Office: 924 Days
• CPC Class Codes: B01D 2317/02 Elements in series
• CPC Class Codes: B01D 2321/04 Backflushing
• CPC Class Codes: B01D 2321/12 Use of permeate
• CPC Class Codes: B01D 61/428 Membrane capacitive deionization
• CPC Class Codes: B01D 61/52 Accessories; Auxiliary operation
• CPC Class Codes: B01D 61/54 Controlling or regulating
• CPC Class Codes: B01D 65/02 Membrane cleaning or sterilisation ; Membrane regeneration
• CPC Class Codes: 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
• CPC Class Codes: C02F 1/008 Control or steering systems not provided for elsewhere in subclass C02F
• CPC Class Codes: C02F 1/32 with ultraviolet light
• CPC Class Codes: C02F 1/441 by reverse osmosis
• CPC Class Codes: C02F 1/444 by ultrafiltration or microfiltration
• CPC Class Codes: C02F 1/4695 electrodeionisation
• CPC Class Codes: C02F 2201/46115 Electrolytic cell with membranes or diaphragms
• CPC Class Codes: C02F 2201/4613 Inversing polarity
• CPC Class Codes: C02F 2201/46145 Fluid flow
• CPC Class Codes: C02F 2209/003 Downstream control, i.e. outlet monitoring, e.g. to check the treating agents, such as halogens or ozone, leaving the process
• CPC Class Codes: C02F 2209/005 Processes using a programmable logic controller [PLC]
• CPC Class Codes: C02F 2209/40 Liquid flow rate
• CPC Class Codes: C02F 2301/08 Multistage treatments, e.g. repetition of the same process step under different conditions
• CPC Class Codes: C02F 2303/16 : Regeneration of sorbents, filters
• CPC Class Codes: Y10T 137/8593 : Systems

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

1. A method of purifying water, comprising:

flowing water from a source along a flow path defined by automatic valves through a plurality of electronic deionization cells in a series, each of the cells having an inlet that receives input water and an outlet that outputs filtered water when flow through the cell is in a forward direction, a first cell encountered by the water in the series having a lowest rank in the series, the rank increasing along the series, and a last cell encountered by the water in the series having a highest rank in the series; and

periodically changing a configuration of the flow path by controlling the automatic valves by a controller, wherein

a first portion of the water that has passed through all cells except the cell having the highest rank is collected as purified water,

a second portion of said water that has passed through all cells except the cell having the highest rank flows through the cell having the highest rank in a reverse direction, opposite of the forward direction, to regenerate said cell having the highest rank, and

said periodically changing the configuration of the flow path includes

switching the automatic valves such that in a changed flow path configuration the cell having the lowest rank becomes the cell having the highest rank that receives water in the reverse direction and a rank of each other cell decrements to a next lower rank, respectively.

2. The method of claim 1, further comprising:

repeating the periodically changing the configuration.

3. The method of claim 1, further comprising:

repeating the flowing the water from the source and the periodically changing the configuration of the flow path multiple times so that each cell takes more than one turn at each rank and is regenerated substantially an equal number of times.

4. The method of claim 3, wherein each cell contains more than one water purification module arranged in series or in parallel.

5. A method of purifying fluid, comprising:

using a controller and a fluid management system, directing the fluid serially through a plurality of cells, each cell of the plurality of cells having a single flow path through which said fluid flows and trapping impurities present in the fluid flowing along said single flow path to purify the fluid in multiple stages while regenerating at least one cell of the plurality of cells such that fluid is purified continuously by cells other than said one cell of the plurality of cells without interruption for the regenerating; and

using the controller and fluid management system, changing flow paths of the fluid management system so that the directing and regenerating are effective to subject each cell of the plurality of cells to an equal filtering load so that each cell is exhausted at the same time, after being subjected to multiple instances of said regenerating, wherein the fluid is water and the cells are electronic deionization cells.

6. The method of claim 5, wherein

the changing of the flow paths includes flowing fluid in a reverse direction through a respective cell during said regenerating and flowing fluid in a forward direction through respective cells during said directing.