Pulsed electric field for drinking water disinfection

Patent metadata

Field	Value
Publication number	US-10577264-B2
Application number	US-201314442588-A
Country	US
Kind code	B2
Filing date	Nov 21, 2013
Priority date	Nov 21, 2012
Publication date	Mar 3, 2020
Grant date	Mar 3, 2020

Abstract

The present disclosure relates to a micro-mini pulsed electric field (PEF) device for point-of-use disinfection of drinking water. The pulsed electric field device comprises micro-engineered electrodes and a low-voltage pulsed electric field generator circuit. A pulsed electric field is generated across a micro-gap between the electrodes to achieve disinfection of drinking water.

First claim

What is claimed is:

1. A tap-mounted device for point-of-use disinfection of water, said device comprising:
a plurality of electrodes having a micro-gap between the electrodes, wherein the micro-gap has a micro-gap distance in the range of 10 μm to 300 μm, the electrodes selected from the group consisting of multi-rod electrodes and jelly-roll type electrodes;
a control system; and
a low-voltage pulsed electric field generator circuit responsive to the control system, to generate a low-voltage pulsed electric field (PEF) across the micro-gap of the electrodes to provide a voltage of about 5 V up to about 30 V across the micro-gap, thereby providing a pulsed electric field strength at a level effective to increase cell permeability and/or cause an irreversible damage to cells of microorganisms present in the water, wherein the micro-gap establishes a distance between the electrodes sufficient to provide a physical separation between the electrodes while permitting a sufficiently intense pulsed electric field generated across a micro-gap between the electrodes to achieve disinfection of drinking water;
wherein the tap mounted device creates a fluid flow path from an inlet to an outlet and the fluid flow path passes through multiple electric fields;
wherein the multi-rod electrodes comprise a plurality of positive electrode rods and a plurality of negative electrode rods arranged in a three dimensional array, wherein an area between the electrode rods is open; and
wherein the jelly-roll type electrodes have multiple fluid flow paths that run traverse to an axis of the electrodes and each fluid flow path passes through multiple electric fields, the jelly-roll type electrodes including a rolled-up substrate, wherein the substrate has positive and negative electrodes on each side.

2. The device of claim 1 further comprising:
a power converter capable of providing a DC power output; and
the power converter providing the DC power output to the low-voltage pulsed electric field generator circuit.

3. The device of claim 1 , wherein the low-voltage pulsed electric field generator circuit provides an output pulse frequency in the range of about 1 Hertz (Hz) to about 100 Hz.

4. The device of claim 1 , wherein the low-voltage pulsed electric field generator circuit provides a pulse width in the range of about 20 nanoseconds to about 100 milliseconds.

5. The device of claim 1 , wherein the micro-gap has a micro-gap dimension from about 10 μm up to about 100 μm.

6. The device of claim 1 , wherein the low-voltage pulsed electric field generator circuit generates a pulsed electric field strength of at least 0.5 kV/cm.

7. The device of claim 1 , wherein the low-voltage pulsed electric field generator circuit generates an electric field having a pulsed waveform selected from the group of square, sinusoidal, trapezoidal and triangular.

8. The device of claim 1 , wherein the electrodes are installed so as to generate an electric field in a direction which is perpendicular or parallel to a water flow between the electrodes.

9. The device of claim 1 , wherein the electrodes are made of a conducting material or a carbon-based material.

10. The device of claim 1 , wherein the electrodes are coated with a conducting material or a carbon-based material.

11. The device of claim 1 , wherein the electrodes are coated electrodes.

12. The device of claim 1 , wherein the electrodes are printed electrodes, and the electrodes are printed on both sides of a substrate with the positive electrodes on one side and the negative electrodes on the other side, wherein the substrate is rolled up into a jelly-roll type electrode.

13. The device of claim 1 , wherein the negative electrode rods are attached to a negative holding plate at one end and the positive electrode rods are attached to a positive holding plate at one end, wherein the electrode rods are aligned parallel to each other with the positive holding plate on one side of the array and the negative holding plate on the other side of the array.

14. The device of claim 1 , wherein a complete perimeter of the electrode rods is directly exposed to the fluid flow path.

15. A method for point-of-use disinfection of water comprising:
providing a plurality of electrodes having a micro-gap between the electrodes, wherein the micro-gap has a micro-gap distance in the range of 10 μm to 300 μm, the electrodes comprising electrodes selected from the group consisting of multi-rod electrodes and jelly-roll type electrodes;
providing a control system;
providing a low-voltage pulsed electric field generator circuit responsive to the control system; and
generating the pulsed electric field (PEF), across the micro-gap of the electrodes to provide a voltage of about 5 V up to about 30 V across the micro-gap, thereby providing a pulsed electric field strength at a level effective to increase cell permeability and/or achieve an irreversible breakdown of cells of microorganisms present in the water, wherein the micro-gap establishes a distance between the electrodes sufficient to provide a physical separation between the electrodes while permitting a sufficiently intense pulsed electric field generated across a micro-gap between the electrodes to achieve disinfection of drinking water;
wherein the tap mounted device creates a fluid flow path from an inlet to an outlet and the fluid flow path passes through multiple electric fields;
wherein the electrodes are multi-rod electrodes which comprise a plurality of positive electrode rods and a plurality of negative electrode rods arranged in a three dimensional array, wherein the space between the electrode rods is open; and
wherein the jelly-roll type electrodes have multiple fluid flow paths that run traverse to an axis of the electrodes and each fluid flow path passes through multiple electric fields, the jelly-roll type electrodes including a rolled-up substrate, wherein the substrate has positive and negative electrodes on each side.

16. The method of claim 15 comprising providing a pulsed electric field strength of at least 0.5 kV/cm.

17. The method of claim 15 , further comprising:
the generating the pulsed electric field (PEF) comprising providing a DC power output to the low-voltage pulsed electric field generator circuit.

18. The method of claim 15 , further comprising using the low-voltage pulsed electric field generator circuit to provide an output pulse frequency in the range of about 1 Hertz (Hz) to about 100 Hz.

19. The method of claim 15 , further comprising using the low-voltage pulsed electric field generator circuit to provide a pulse width in the range of about 20 nanoseconds to about 100 milliseconds.

20. The method of claim 15 , further comprising:
using the low-voltage pulsed electric field generator circuit to provide an output pulse frequency in the range of about 1 Hertz (Hz) to about 100 Hz; and
using the low-voltage pulsed electric field generator circuit to generate a pulsed electric field strength of at least 0.5 kV/cm.

21. The method of claim 15 , further comprising using the low-voltage pulsed electric field generator circuit to generate an electric field having a pulsed waveform selected from the group of square, sinusoidal, trapezoidal and triangular.

Assignees

• Univ Hong Kong Sci & Tech

Inventors

• Yeung King Lun
• Kwan Joseph Kai Cho
• Kwan Siu Ming
• Lam Ka Wo

Classifications

• C02F2001/46133

  characterised by the material · CPC title

• C02F2307/10

  as part of a potable water dispenser, e.g. for use in homes or offices · CPC title

• C02F2201/48

  Devices for applying magnetic or electric fields · CPC title

• C02F2307/12

  as part of household appliances such as dishwashers, laundry washing machines or vacuum cleaners · CPC title

• C02F2001/46152

  characterised by the shape or form · CPC title