Water Purification System And Method

Patent metadata

Field	Value
Publication number	US-2018318767-A1
Application number	US-201515525710-A
Country	US
Kind code	A1
Filing date	Oct 28, 2015
Priority date	Nov 11, 2014
Publication date	Nov 8, 2018
Grant date	—

Abstract

A laboratory scale water purification system for producing up to 300 l/h deionized type 2 pure water from tap water, said system comprising a feed medium flow path including a pump (1) for supplying the feed medium under pressure to a feed inlet of a reverse-osmosis (RO) device (2) which is adapted to produce a permeate flow and a concentrate flow from the feed medium. An electro-deionization (EDI) device (10) is provided and has an inlet which is in fluid communication with a permeate outlet of the RO device (2) and has a purified water outlet. The system has a first retentate flow path (A) in fluid communication with the retentate 1 outlet of the RO device (2), for removing retentate from the system, the first retentate flow path (A) including a first flow rate regulator (3) adapted to be remote controlled, and a second retentate flow path (B) in fluid communication with the retentate outlet of the RO device (2) for recirculating retentate to the feed medium flow path at an upstream position of the pump (1), the second retentate flow path (B) including a second flow rate regulator (4) adapted to be remote controlled. A first flow meter (5) is provided downstream of the permeate outlet for detecting the permeate flow rate produced by the RO device (2), a second flow meter (6) is provided in the first retentate flow path (A) downstream of the first flow rate regulator (3) for detecting the flow rate of the retentate flow that is removed from the system, and an automatic controller (13) is provided for remote controlling the first and second flow rate regulators (3,4) based on the detection results from the first and second flow meters (5,6) such that a predetermined target recovery rate and a predetermined target permeate flow rate are controlled for the RO device (2).

First claim

1 . A laboratory scale water purification system for producing up to 300 l/h deionized type 2 pure water from tap water, said system comprising:
a feed medium flow path (C) including a pump ( 1 ) for elevating the pressure of the feed medium and supplying the feed medium under pressure to a feed inlet of a reverse-osmosis device ( 2 ), wherein the reverse-osmosis device ( 2 ) is adapted to produce a permeate flow and a concentrate flow from the feed medium and has a permeate outlet and a retentate outlet; an electro-deionization device ( 10 ) having an inlet in fluid communication with the permeate outlet of the reverse-osmosis device ( 2 ), and a purified water outlet; a first retentate flow path (A) in fluid communication with the retentate outlet of the reverse-osmosis device ( 2 ), for removing retentate from the system, said first retentate flow path (A) including a first flow rate regulator ( 3 ) adapted to be remote controlled; a second retentate flow path (B) in fluid communication with the retentate outlet of the reverse-osmosis device ( 2 ) for recirculating retentate to the feed medium flow path at an upstream position of the pump ( 1 ), said second retentate flow path (B) including a second flow rate regulator ( 4 ) adapted to be remote controlled; a first flow meter ( 5 ) downstream of the permeate outlet for detecting the permeate flow rate produced by the reverse-osmosis device ( 2 ); a second flow meter ( 6 ) provided in the first retentate flow path (A) downstream of the first flow rate regulator ( 3 ) for detecting the flow rate of the retentate flow that is removed from the system; and an automatic controller ( 13 ) for remote controlling the first and second flow rate regulators ( 3 , 4 ) based on the detection results from the first and second flow meters ( 5 , 6 ) such that a predetermined target recovery rate and a predetermined target permeate flow rate are controlled for the reverse-osmosis device ( 2 ).

2 . A laboratory scale water purification system for producing up to 300 l/h deionized type 2 pure water from tap water, said system comprising:
a feed medium flow path (C,E) including a pump ( 1 ) for elevating the pressure of the feed medium and supplying the feed medium under pressure to a feed inlet of a reverse-osmosis device ( 2 ), wherein the reverse-osmosis device ( 2 ) is adapted to produce a permeate flow and a concentrate flow from the feed medium and has a permeate outlet and a retentate outlet; an electro-deionization device ( 10 ) having an inlet in fluid communication with the permeate outlet of the reverse-osmosis device ( 2 ), and a purified water outlet; a first retentate flow path (A) in fluid communication with the retentate outlet of the reverse-osmosis device ( 2 ), for removing retentate from the system, said first retentate flow path (A) including a first flow rate regulator ( 3 ) adapted to be remote controlled; a second retentate flow path (B) in fluid communication with the retentate outlet of the reverse-osmosis device ( 2 ) for recirculating retentate to the feed medium flow path at an upstream position of the pump ( 1 ), said second retentate flow path (B) including a second flow rate regulator ( 4 ) adapted to be remote controlled; a first flow meter ( 5 ) downstream of the permeate outlet for detecting the permeate flow rate produced by the reverse-osmosis device ( 2 ); a first conductivity cell ( 15 ) provided in the first retentate flow path (A) for detecting the conductivity (ion concentration) of the retentate flow; a second conductivity cell ( 16 ) provided in the feed medium flow path (E) for detecting the conductivity (ion concentration) of the feed medium flow; and an automatic controller ( 13 ) for controlling the first and second flow rate regulators ( 3 , 4 ) based on the detection results from the first flow meter ( 5 ) and the first and second conductivity cells ( 15 , 16 ) such that a predetermined target recovery rate and a predetermined target permeate flow rate are controlled for the reverse-osmosis device ( 2 ).

3 . The laboratory scale water purification system according to claim 1 , wherein, in order to control the predetermined target permeate flow rate, said controller ( 13 ) is adapted to simultaneously close the first and second flow rate regulators ( 3 , 4 ) to increase the permeate flow rate and/or to simultaneously open the first and second flow rate regulators ( 3 , 4 ) to decrease the permeate flow rate.

4 . The laboratory scale water purification system according to claim 1 , wherein, in order to control the predetermined target recovery rate and to keep the permeate flow rate substantially constant, said controller ( 13 ) is adapted to close the second flow rate regulator ( 4 ) and open the first flow rate regulator ( 3 ) to decrease the recovery rate of the reverse-osmosis device ( 2 ), and/or to open the second flow rate regulator ( 4 ) and close the first flow rate regulator ( 3 ) to increase the recovery rate for the reverse-osmosis device ( 2 ).

5 . The laboratory scale water purification system according to claim 1 , wherein,
in order to control a predetermined target minimum recovery pressure, said controller ( 13 ) is adapted to simultaneously close the first and second flow rate regulators ( 3 , 4 ) to increase the recovery pressure; and/or in order to control a predetermined target maximum recovery pressure, said controller ( 13 ) is adapted to simultaneously open the first and second flow rate regulators ( 3 , 4 ) to decrease the recovery pressure; and/or in order to control a predetermined target recovery pressure variation, said controller ( 13 ) is adapted to simultaneously decrease the closing or opening speeds of the first and second flow rate regulators ( 3 , 4 ) to decrease the recovery pressure variation.

6 . The laboratory scale water purification system according to claim 1 ,
wherein, in order to control the predetermined target recovery rate and to keep the permeate flow rate substantially constant, said controller ( 13 ) is adapted to close the second flow rate regulator ( 4 ) and open the first flow rate regulator ( 3 ) to decrease the recovery rate of the reverse-osmosis device ( 2 ), and/or to open the second flow rate regulator ( 4 ) and close the first flow rate regulator ( 3 ) to increase the recovery rate for the reverse-osmosis device ( 2 ), and wherein said controller ( 13 ) is adapted to control the predetermined target recovery rate in a closed loop (feedback control), and wherein said controller ( 13 ) is adapted to determine the current recovery rate of the reverse-osmosis device ( 2 ) based on the detection result of the first and second flow meters ( 5 , 6 ) according to the following relation:
(recovery rate of the reverse-osmosis device (2))=(permeate flow rate at the outlet of the reverse-osmosis device (2))/(permeate flow rate at the outlet of the reverse-osmosis device (2)+flow rate of the retentate flow that is removed from the system).

7 . The laboratory scale water purification system according to claim 2 ,
wherein, in order to control the predetermined target recovery rate and to keep the permeate flow rate substantially constant, said controller ( 13 ) is adapted to close the second flow rate regulator ( 4 ) and open the first flow rate regulator ( 3 ) to decrease the recovery rate of the reverse-osmosis device ( 2 ), and/or to open the second flow rate regulator ( 4 ) and close the first flow rate regulator ( 3 ) to increase the recovery rate for the reverse-osmosis device ( 2 ), and wherein said controller ( 13 ) is adapted to control the predetermined target recovery rate in a closed loop (feedback control).

8 . The laboratory scale water purification system according to claim 1 , wherein a pressure

Assignees

• Merck Patent Gmbh

Inventors

• Roitel Pascal
• Paragot Christophe
• Feuillas Emmanuel
• Dupont Stephane

Classifications

• C02F9/20 Primary

  Portable or detachable small-scale multistage treatment devices, e.g. point of use or laboratory water purification systems · CPC title

• B01D2311/243

  Electrical conductivity control · CPC title

• C02F2209/03

  Pressure · CPC title

• B01D2311/14

  Pressure control · CPC title

• B01D2311/25

  Recirculation, recycling or bypass, e.g. recirculation of concentrate into the feed · CPC title