System and Method for Treating Water Systems with High Voltage Discharge and Ozone

• US 20150232353A1
• Filed: 04/24/2015
• Published: 08/20/2015
• Est. Priority Date: 05/01/2013
• Status: Active Grant

• Current Assignee: NCH Corporation
• Original Assignee: NCH Corporation
• Inventors: Denvir, Adrian J., Vela, David F., Evaro, Jose E., Holloway, Matthew C., Boesch, William P.
• Granted Patent: US 9,932,252 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01F 2101/305 Treatment of water, waste water or sewage
• CPC Class Codes: B01F 23/23121 having injection means, e.g. nozzles with circumferential outlet
• CPC Class Codes: B01F 23/237613 Ozone
• CPC Class Codes: C02F 1/4608 using electrical discharges
• CPC Class Codes: C02F 1/4672 by electrooxydation
• CPC Class Codes: C02F 1/78 with ozone C02F1/4672 takes precedence
• CPC Class Codes: C02F 2103/02 Non-contaminated water, e.g. for industrial water supply
• CPC Class Codes: C02F 2201/46105 Details relating to the electrolytic devices
• CPC Class Codes: C02F 2201/46135 Voltage
• CPC Class Codes: C02F 2201/4615 Time
• CPC Class Codes: C02F 2201/46175 Electrical pulses
• CPC Class Codes: C02F 2201/784 Diffusers or nozzles for ozonation
• CPC Class Codes: C02F 2303/04 Disinfection
• CPC Class Codes: C02F 2303/26 Reducing the size of particles, liquid droplets or bubbles, e.g. by crushing, grinding, spraying, creation of microbubbles or nanobubbles

Abstract

A system and method for treating flowing water systems with a plasma discharge to remove or control growth of microbiological species. Components of the water system are protected from being damaged by excess energy from the electrohydraulic treatment. Ozone gas generated by a high voltage generator that powers the plasma discharge is recycled to further treat the water. A gas infusion system may be used to create fine bubbles of ozone, air, or other gases in the water being treated to aid in plasma generation, particularly when the conductivity of the water is high. An electrode mounting assembly maintains a high voltage electrode and ground electrode at a fixed distance from each other to optimize plasma generation. An open support structure for the high voltage generator circuit physically separates spark gap electrodes and resists metal deposits that may disrupt discharge of a high voltage pulse to create the plasma.

Claims

1. A treatment system for treating water in a flowing water system with a plasma discharge and ozone, the treatment system comprising:

a high voltage generator comprising a plurality of capacitors, resistors, and spark gap electrodes configured in a Marx ladder circuit, a support structure for the spark gap electrodes, and a housing;

a reaction chamber comprising an inlet configured to receive at least a portion of water flowing through the water system as water to be treated, an outlet configured to return the portion of water back to the water system after being treated with a plasma discharge and ozone, and a reactor body;

a gas infusion system disposed upstream of the inlet or within the reaction chamber to add bubbles of one or more gases into the water to be treated;

a high voltage electrode and a ground electrode at least partially disposed in the reaction chamber and configured to generate a plasma discharge within the reactor body when a high voltage pulse is produced by the high voltage generator; and

a conduit configured to deliver ozone gas produced in the high voltage generator from the housing to the gas infusion system.

2. The treatment system of claim 1 further comprising an electrode mounting assembly disposed within the reaction chamber, the electrode mounting assembly comprising a high voltage mounting base connected to the high voltage electrode and a ground mounting base connected to the ground electrode.

3. The treatment system of claim 2 wherein the high voltage mounting base comprises a wheel-like body.

4. The treatment of claim 3 wherein the ground electrode mounting base comprises a funnel or dome shaped body.

5. The treatment system of claim 2 wherein the high voltage mounting base and ground mounting base are configured to hold the high voltage electrode a fixed gap distance between around 1 and 10 mm from the ground electrode.

6. The treatment system of claim 5 wherein the ground electrode comprises a substantially cylindrical and conductive tube having a plurality of apertures disposed through a sidewall of the tube, wherein the tube is disposed between the ground electrode mounting base and the high voltage mounting base.

7. The treatment system of claim 6 wherein the high voltage electrode comprises a rod that is at least partially disposed within and substantially concentric with the ground electrode tube and wherein the gap distance is a radial distance between an exterior surface of the rod and interior surface of the tube

8. The treatment system of claim 7 wherein around 4 to 30 mm of the rod is disposed within the ground electrode tube.

9. The treatment system of claim 6 wherein an exterior surface of the tube is coated with a dielectric barrier material.

10. The treatment system of claim 1 wherein the support structure for the spark gap electrodes comprises:

an upper support arm having a substantially rectangular configuration with an open central portion,

a lower support arm having a substantially rectangular configuration with an open central portion,

one or more vertical support arms connecting the upper support arm to the lower support arm in a spaced-apart relationship;

a plurality of spaced-apart post pairs, each pair comprising a first post extending vertically from a first side of the lower support arm and a second post extending vertically from a second side of the lower support arm substantially opposite the first side.

11. The treatment system of claim 10 wherein the upper support arm, lower support arm, and vertical support arms form an open, substantially U-shaped frame.

12. The treatment system of claim 10 wherein the support structure has dimensions of around 2 inches wide by 2 inches high to 3 inches wide by 3 inches high.

13. The treatment system of claim 10 wherein the support structure further comprises a plurality of electrode mounts, each mount extending inwardly from each of the first posts and each the second posts of the spaced-apart post pairs,

wherein each electrode mount is attached to one of the spark gap electrodes to form a plurality of electrode pairs between each spaced-apart post pair;

and

14. wherein a gap distance between the spark gap electrodes in each electrode pair is around 15 mm to 40 mm. The treatment system of claim 13 wherein the spark gap electrodes are configured to move laterally along the electrode mounts to selectively adjust the gap distance.

15. The treatment system of claim 14 wherein the electrode mounts comprises threads configured to mate with threads on the spark gap electrodes so that the spark gap electrodes may be rotated to achieve lateral movement along the electrode mounts.

16. The treatment system of claim 13 wherein the electrode mounts are configured to move laterally relative to the posts to selectively adjust the gap distance.

17. The treatment system of claim 1 further comprising an oil bath disposed within the housing.

18. The treatment system of claim 17 wherein the support structure comprises a lower support arm disposed below the spark gap electrodes and the lower support arm is submerged in the oil bath.

19. The treatment system of claim 17 wherein the capacitors are at least partially submerged in the oil bath.

20. The treatment system of claim 1 wherein the surfaces of the support structure are coated with oil.

21. The treatment system of claim 1 further comprising a venturi or vacuum pump to draw ozone generated in the high voltage generator into the conduit for delivery to the gas infusing system.

22. The treatment system of claim 1 further comprising an air pump to blow air through the high voltage generator.

23. A method of treating a flowing water stream, the method comprising:

generating a high voltage pulse and ozone using a Marx ladder circuit comprising a plurality of capacitors, resistors, and spark gap switches, wherein the spark gap switches are supported by an open support structure;

operating the Marx ladder circuit at reduced pressure or under negative pressure;

contacting at least a portion of the support structure with oil to reduce metal deposits on the support structure; and

supplying ozone to the flowing water stream.

24. The method of claim 23 further comprising the step of periodically cleaning the support structure to remove the oil and supplying fresh oil to contact at least a portion of the support structure.

25. The method of claim 23 wherein each spark gap switch comprises a pair of electrodes separated by a gap distance and wherein the open support structure is configured to support the plurality of spark gap switches so that the gap distance is between about 15 mm and 40 mm.

26. The method of claim 23 further comprising:

supplying the high voltage pulse to a high voltage electrode at least partially disposed in a reaction chamber, wherein the reaction chamber has an inlet and an outlet though which the water stream flows;

generating a plasma discharge in the flowing water stream between the high voltage electrode and a ground electrode at least partially disposed in the reaction chamber.

27. The method of claim 26 further comprising adding bubbles of one or more gases into the flowing water stream in an area where the plasma discharge occurs.

28. The method of claim 27 further comprising periodically measuring the conductivity of the flowing water stream and adjusting one or more operating parameters when the conductivity is above a predetermined threshold.

29. The method of claim 28 wherein the one or more operating parameters are adjusted by one or more of the following steps:

moving the high voltage electrode and the ground electrode closer together;

increasing a voltage of the high voltage pulse supplied to the high voltage electrode;

increasing a rate of adding bubbles into the flowing water stream; and

reducing the pressure of the flowing water stream at the outlet of the reaction chamber.

30. The method of claim 25 further comprising adjusting a voltage of the high voltage post by increasing or decreasing the gap distance.

31. The method of claim 30 wherein the open support structure comprises a frame, plurality of posts supported by the frame, and a plurality of electrode mounts supported by the posts, wherein each electrode mount supports one of the spark gap electrodes;

wherein the gap distance is increased or decreased by laterally moving the spark gap electrodes relative to the electrode mounts or laterally moving the electrode mounts relative to the posts.

32. The method of claim 23 further comprising periodically measuring the conductivity of the flowing water stream and adjusting one or more operating parameters when the conductivity is above a predetermined threshold.