System and method for purifying liquid by reverse osmosis

Patent metadata

Field	Value
Publication number	US-10874985-B2
Application number	US-201716463496-A
Country	US
Kind code	B2
Filing date	Nov 22, 2017
Priority date	Nov 24, 2016
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

A system for purifying a treated liquid, including:
a treatment module, for treating the liquid and providing a purified liquid, and a residual liquid; and a means for pressurizing said treated liquid to supply said treatment module, including:
a master cylinder, driven by a working fluid, and at least slave cylinder, driven by said master cylinder, receiving said treated liquid and supplying it to said treatment module;

a cross section of said master cylinder is greater than a cross section of said slave cylinder so that, a greater pressure is generated on the treated liquid in the slave cylinder; and a means for pre-pressurizing the treated liquid, upstream of the pressurizing means, including:

at least one master cylinder, connected to the treatment module, and driven by the residual liquid, and a slave cylinder, containing the treated liquid, driven by said master cylinder.

First claim

The invention claimed is:

1. A system for purifying a liquid to be treated, comprising:
a module, called treatment module, for treating the liquid to be treated and providing a purified liquid, and a residual liquid; and
a means for pressurizing the liquid to be treated to supply said treatment module, comprising:
a cylinder, called a master cylinder, provided to be driven by a fluid, called a working fluid; and
at least one cylinder, called a slave cylinder, driven by said master cylinder, provided to receive the liquid to be treated and supply the liquid to be treated to said treatment module;

a cross section of said master cylinder is greater than a cross section of said at least one slave cylinder so that, for a given pressure of said working fluid in the master cylinder, a greater pressure is generated on the liquid to be treated in the slave cylinder; and a means for pre-pressurizing the liquid to be treated, upstream of the pressurizing means; said pre-pressurizing means comprising:
at least one cylinder, called a master cylinder, connected to the treatment module, and driven by the residual liquid provided by the treatment module; and
a cylinder, called a slave cylinder, containing the liquid to be treated, driven by said at least one master cylinder.

2. The system according to claim 1 , wherein the treatment module is a module for treating the liquid to be treated by reverse osmosis.

3. The system according to claim 1 , wherein the master cylinder is a double-acting cylinder, and the pressurizing means comprises two slave cylinders, situated symmetrically on both sides of the master cylinder, and driven by said master cylinder.

4. The system according to claim 1 , further comprising a reservoir, called intermediate reservoir, arranged to store the liquid to be treated at an intermediate pressure, less than an osmotic pressure, at an outlet of the means for pre-pressurizing the liquid to be treated and to supply the pressurizing means with the liquid to be treated.

5. The system according to claim 1 , wherein the working fluid is a thermal fluid, a pressure of which varies as a function of a temperature of the working fluid, said system comprising a thermal device, arranged upstream of the pressurizing means, and carrying out a heat exchange towards said working fluid, so as to increase its pressure.

6. The system according to claim 1 , wherein the working fluid is an incompressible fluid, said system comprising:
a thermal device, arranged upstream of the pressurizing means, and carrying out a heat exchange towards a thermal fluid, so as to increase the pressure of said thermal fluid; and
a pressure transfer means, arranged between said thermal device and the pressurizing means, to transmit the pressure from said thermal fluid to the working fluid.

7. The system according to claim 6 , wherein the pressure transfer means comprises:
at least one cylinder, called transfer cylinder, connected to the pressurizing means, and provided to receive the working fluid; and
at least one deformable volume, arranged in said transfer cylinder, and provided to receive the thermal fluid.

8. The system according to claim 5 , wherein the thermal fluid is a fluid selected from: saturated or unsaturated C5- to C10-type hydrocarbons, organic fluids or mixtures of azeotropic or non-azeotropic organic fluids.

9. The system according to claim 5 , further comprising a thermal fluid pre-pressurizing means, arranged upstream of the thermal device.

10. The system according to claim 9 , wherein the thermal fluid pre-pressurizing means comprises:
at least one cylinder, called master cylinder, driven by the residual liquid provided by the treatment module; and
a cylinder, called slave cylinder, containing the thermal fluid, driven by said at least one master cylinder.

11. A method for purifying a liquid, called a liquid to be treated, comprising at least one iteration of the following steps:
pressurizing the liquid to be treated;
supplying said pressurized liquid to be treated to a treatment module providing a first liquid, called a purified liquid, and a second liquid, called a residual liquid;
the pressurizing step is carried out by at least one cylinder, called a slave cylinder, firmly connected to a cylinder, called a master cylinder, with a cross section larger than the cross section of said slave cylinder, and receiving a working fluid; and a step of pre-pressurizing the liquid to be treated, before the step of pressurizing the liquid to be treated, carried out by a cylinder, called slave cylinder, containing the liquid to be treated, firmly connected to at least one cylinder, called master cylinder, receiving the residual liquid.

12. The method according to claim 11 , wherein the treatment module is a module for treating liquid to be treated by reverse osmosis.

13. The method according to claim 11 , wherein the master cylinder is a double-acting cylinder, and drives two slave cylinders so that, when one of the slave cylinders is emptied of liquid to be treated, the other slave cylinder is simultaneously filled with liquid to be treated.

14. The method according to claim 11 , wherein the working fluid is a thermal fluid, said method comprising a step of increasing the pressure of said working fluid by heat exchange.

15. The method according to claim 11 , wherein the working fluid is an incompressible fluid, said method comprising the following steps:
a step of heat exchange towards a thermal fluid in order to increase the pressure of said thermal fluid; and
a step of transferring pressure from said thermal fluid to saidworking fluid.

16. The method according to claim 15 , wherein the pressure transfer step is carried out by at least one cylinder containing the working fluid and an elastic bladder, arranged in said cylinder, and containing the thermal fluid.

17. The method according to claim 14 , further comprising a step of pre-pressurizing the thermal fluid, carried out by a cylinder, called slave cylinder, containing the thermal fluid, firmly connected to at least one cylinder, called master cylinder, receiving the residual liquid.

18. The method according to claim 15 , further comprising two half cycles, each half cycle comprising the following phases:
a phase I simultaneously comprising:
increasing the pressure of the thermal fluid by heat exchange; and
transferring pressure from said thermal fluid to said working fluid;

a phase II simultaneously comprising:
increasing the pressure of the thermal fluid by heat exchange;
transferring pressure from said thermal fluid to said working fluid;
pressurizing the liquid to be treated;
purifying the liquid to be treated by reverse osmosis; and
pre-pressurizing the thermal fluid;

a phase III simultaneously comprising:
increasing the pressure of the thermal fluid by heat exchange;
transferring pressure from said thermal fluid to said working fluid;
pressurizing the liquid to be treated;
purifying the liquid to be treated by reverse osmosis; and
pre-pressurizing the liquid to be treated; and

a phase IV comprising a step of pre-pressurizing the liquid to be treated.

19. The system according to claim 1 , wherein said master cylinder and said slave cylinder each include a piston.

20. The method of claim 11 , wherein said master cylinder and said slave cylinder each include a piston.

Assignees

• Centre Nat Rech Scient

Inventors

• Stitou Driss
• Mazet Nathalie
• Mauran Sylvain

Classifications

• B01D61/08

  Apparatus therefor · CPC title

• F04B9/125

  reciprocating movement of the pumping member being obtained by a double-acting elastic-fluid motor · CPC title

• B01D61/025

  Reverse osmosis; Hyperfiltration · CPC title

• B01D2313/24

  Specific pressurizing or depressurizing means · CPC title

• F04B9/133

  reciprocating movement of the pumping members being obtained by a double-acting elastic-fluid motor · CPC title