EP2051939A1

EP2051939A1 - A system for electrode cleaning

Info

Publication number: EP2051939A1
Application number: EP07732073A
Authority: EP
Inventors: Christian J. Gauthier
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-03-20
Filing date: 2007-03-20
Publication date: 2009-04-29
Also published as: GB2436330A; GB0605546D0; WO2007107741A1

Abstract

The present invention relates to a cleaning system (10) for use in cleaning an electrode of an ion generator (11) in situ, the system comprising: an isolator (V2,V3), which when actuated, isolates the ion generator (11) from the fluid supply it is treating; and an inlet (50) through which a cleaning agent can be dispensed into the ion generator (11) such that the electrode of the ion generator (11) is exposed to the cleaning agent.

Description

A SYSTEM FOR ELECTRODE CLEANING

Description of Invention

The present invention relates to a cleaning system and cleaning process. In particular, the present invention relates to a cleaning system and process for cleaning an internal surface of a system, which, in use, carries a fluid such as a liquid, in particular, water. More particularly, the present invention relates to a cleaning system and process for cleaning the surface of an electrode of an apparatus for introducing ions into a flow of water or a water supply, known in the art as an ion generator.

Legionnaires' disease is a type of pneumonia. It was named after an outbreak of severe pneumonia, which affected a convention of the American

Legionnaires in 1976. One of the most common species of bacteria, which causes Legionnaires disease is called Legionella pneumophila. People can contract Legionnaires disease by inhaling small droplets of water suspended in the air, which contain the legionella bacterium. This bacterium is widespread in nature and it mainly lives in water, for example, ponds, where it does not usually cause problems. Outbreaks of Legionnaires disease occur from purpose built water systems where temperatures are warm enough to encourage growth of the bacteria, e.g. in cooling towers, evaporative condensers and whirlpool spas, and from water used for domestic purposes in cruise ships and buildings such as hotels, hospitals, nursing homes and office buildings and the like. Other water borne bacteria can also cause infections, in particular, lung infections, such as pseudomonas bacteria.

Pontiac fever, a flu-like illness caused by the bacterium Legionella pneumophila contracted by breathing mist that comes from a water source

(such as air conditioning cooling towers, whirlpool spas, showers) contaminated with the bacteria. The incubation period is short, from a few hours to 2 days, before the onset of fever and muscle aches. Persons with Pontiac fever do not have pneumonia. They generally recover in 2 to 5 days without treatment. Pontiac fever is so-named because of an outbreak in 1968 in Pontiac, Michigan. It is a milder form of legionellosis than Legionnaire disease which is caused by the same bacterium

With a view to suppressing growth of and/or eradicating micro-organisms, for example, water borne bacteria such as Legionella from a supply of water or biofilm, which has built up on an internal surface of a water supply network, it is known to expose the water and/or biofilm to ions; said ions being induced by metallic electrodes, which are part of an ion generator.

Biofilm forms when bacteria adhere to surfaces in aqueous environments and begin to excrete a slimy, glue-like substance that can anchor them to all kinds of material - such as metals, plastics, soil particles, medical implant materials, and tissue. A biofilm can be formed by a single bacterial species, but more often biofilms consist of many species of bacteria, as well as fungi, algae, protozoa, debris and corrosion products. Essentially, biofilm may form on any surface exposed to bacteria and some amount of water. Once anchored to a surface, biofilm microorganisms carry out a variety of detrimental or beneficial reactions (by human standards), depending on the surrounding environmental conditions.

ion generators generally include at least a pair of electrodes, for example, a pair of pure copper and/or sliver electrodes, or alloys thereof, which, in use, create positive metallic ions when a DC current is passed between such electrodes. The resultant metallic ions, for example, Cu²⁺ and Ag⁺, are released from the positive electrode and are attracted to the other, negatively charged electrode. As will be appreciated, the water flowing between the electrodes will carry the positive metallic ions away into the water system before they actually reach the opposite, negatively charged electrode. These positively charged ions, for example, positively charged copper and silver ions travelling within the water supply system can bind themselves to negatively charged micro-organisms such as Legionella, or other micro-organisms present in the water system, which may be potentially harmful to health. On binding, the positive metallic ions will instigate a multi-phase process, which will ultimately disrupt the overall cell metabolism of the micro-organism resulting in cell lysis, namely, cell death.

Therefore, and as will be appreciated, ion generators can suppress the growth of and/or eradicate micro-organisms from a water supply using safe levels of positive metallic ions they have generated; such levels being below the internationally prescribed guidelines for the level of metallic ions in water.

One of the problems associated with known water treatment systems of the type know in the art as ion generators is that the build-up of scale and other deposits originating from the water supply, such as biomass (sludge), greatly reduces the efficacy and efficiency of the ion generators. In particular, the build-up of scale and other deposits, such as biofilm, produces a physical barrier, producing a higher inter electrode resistance and making it more difficult to maintain a constant current between the electrodes and continue to introduce sufficient amounts of positive ions into the water supply to suppress the growth of and/or eradicate micro-organisms therefrom.

With a view to addressing this problem, at least temporarily, it is known to use a computer controlled variable voltage output power supply to maintain a constant current between the respective electrodes. The use of a variable power supply will enable the ion generator to be effective even when there is a small accumulation of scale and other deposits. That is, a constant current sufficient to induce an effective amount of positive ions can be maintained by increasing the power supply to the electrodes. However, there comes a point when the variable power supply is not sufficient to provide a constant current between the electrodes due to the extent of the build of scale and other deposits common to water supply systems, at which point, the ion generators need to be physically removed from the water supply system, which they serve, to be cleaned, physically and/or chemically. As will be appreciated, the physical removal of the ion generators to be cleaned, and the acts of physically and/or chemically removing scale and other deposits from the electrode's surface are not only time consuming, but also expensive and involves manipulation of chemicals and/or cleaning tools such as scrubbing equipment.

It is an object of the present invention to provide a cleaning system and process which at least addresses the problems identified above.

In a first aspect of the present invention there is provided a cleaning system for use in cleaning an electrode of an ion generator in situ, the system comprising: an isolator, which when actuated, isolates the ion generator from the fluid supply it is treating; and an inlet through which a cleaning agent can be dispensed into the ion generator such that the electrode of the ion generator is exposed to the cleaning agent.

As will be appreciated, because the cleaning system of the present invention can be actuated at any given time to clean the electrode surfaces of an ion generator, the need of having to physically remove the ion generators from the water system and the disadvantages associated therewith are negated. In addition, by utilising the present system on a regular basis, reduces the wear and tear of the ion generators in the sense that the power applied to the electrodes to generate sufficient levels of positive ions need not be varied as regularly as they are with prior art ion generators; the power levels of which need to be increased as the deposit accumulates.

Advantageously, the isolator includes at least two valves, one located at either side of the ion generator.

Preferably, the cleaning system further includes at least one reservoir which stores the cleaning agent, which is preferably in liquid form. It is to be understood that the reservoir may be an integral part of the system, or may be portable such that it can be attached to the system as and when the need arises.

More preferably, the cleaning system further includes at least one pump for dispensing the cleaning agent, which is in liquid form, through the inlet.

Further preferably, the cleaning agent may be a weak acid, like an organic acid, preferably selected from the group consisting of acetic acid (CH3COOH) or benzoic acid (C₆H₅COOH). Alternatively, the cleaning agent may be an inorganic acid such as Muriatic acid or hydrochloric acid (HCI), or a surfactant that can greatly reduce the surface tension of water when used in very low concentrations for the removal of organic based deposits. Bio-Enzymes suspended in liquid solutions can also be used as cleaning agent.

Advantageously, the organic acid is weak in nature, and is capable of removing inorganic deposits such as scale (CaCO₃ deposits) when used on a regular basis. Further preferably, the acid is an organic acid, such as acetic acid or benzoic acid. This has the advantage in that being an organic acid its eventual degradation is environmentally friendly, less corrosive, and moreover, can be safely disposed of subsequent to use without any further treatment and can be let back into the environment. As will be appreciated, this certainly reduces the cost and the safety of cleaning systems of this type, and moreover, makes them environmentally more friendly.

Further preferably, the liquid surfactant solution for biofilm (sludge) dispersant should contain but not limited to: sodium acrylate-silicate ester, acrylate- silicate ester, sodium 2-ethyIhexyl sulphate (C₈Hi₇NaSO₄) and/or sodium dimethylbenzene sulfonate in various concentrations based on the particular cleaning requirements.

Advantageously, the system further includes a detector for detecting that the isolator has isolated the ion generator from the fluid supply it is treating. Preferably, the detector includes a flow meter or flow switch. As will be appreciated, a flow switch measures or detects fluid or water movement, whereas a flow meter can, in addition to detecting movement, can measure the flow volume of the liquid or fluid. Preferably, both the flow switch and flow meter transmit either a digital and/or an analogue signal to the ion generator computer system.

Advantageously, the cleaning system further includes an outlet through which the system can be drained independently. This has the advantage in that the system can be drained without causing cross contamination with the main water distribution system, which is being treated by the ion generator.

Preferably, the outlet is associated with a detector for detecting the flow of fluid to the outlet. Advantageously, the detector is a flow switch or a flow meter as identified above.

More advantageously, the cleaning system further includes a second inlet port through which air can be introduced into or escape from the ion generator. This enables air into the system such that it may be drained.

Further preferably, the inlet includes a valve, which, when actuated, allows air to be introduced or evacuated and avoid differential pressures that could cause liquid flow problems.

Advantageously, the cleaning system further includes a rinser, which when actuated, introduces water into the isolated ion generator such that any cleaning agent can be rinsed from the isolated ion generator. Preferably, the rinser includes at least one valve for introducing rinsing fluid into the ion generator. Further preferably, the valve diverts the flow of the water to be treated into the ion generator.

Most advantageously, the cleaning system is fully automated, preferably by the use of a computer or computerised system. This has the advantage that the whole cleaning cycle can be carried out without any human intervention or involvement.

In a second aspect of the present invention, there is provided an ion generator in communication with a cleaning system of the present invention.

In a third aspect of the present invention, there is provided the use of a cleaning system in accordance with the present invention to clean an ion generator.

In a further aspect of the present invention, there is provided a method for cleaning the electrode of an ion generator in situ utilising the cleaning system of the present invention, the method comprising the steps of: actuating the isolator such that the fluid or water to be treated no longer flows through the ion generator; draining the ion generator; and introducing at least one cleaning agent through the inlet, such that the electrodes of the ion generator are exposed to the cleaning agent. Preferably, the method further includes the steps of: draining the at least one cleaning agent through the outlet.

Advantageously, the method further includes the step of rinsing the surfaces of the electrodes, before the ion generator is exposed to the primary fluid supply to be treated.

Further preferably, the method is fully automated.

One, non-limiting, cleaning system and process in accordance with the present invention will now be described by way of reference to Figure 1 , which illustrates a schematic diagram of a cleaning system of the present invention in communication with an ion generator.

As illustrated in Figure 1, a cleaning system (10) in accordance with the present invention is associated with two ion generators (11), in particular two flow cells which include the electrodes, which may be of the type obtainable from ProCare Water Treatment lnc located within a flow of water to be treated. Although, the cleaning system is associated with a plurality of flow cells (11), it is to be appreciated that it may be associated with one flow cell or more than a plurality of flow cells connected in series or in parallel, or combinations thereof.

When the ion generators (11) are in normal use, i.e. in treatment mode, the first valve (V1) is closed such that the water to be treated can flow through a second valve (V2) thereby passing between the ion producing electrodes provided within the ion generators (11), past the first flow monitor (FM1) and through the third valve (V3) to a suitable outlet (20) through which the treated water can be dispensed for use, such as a tap. In the event that the electrodes within the ion generators (11) are scheduled to be cleaned, the first valve (V1) is opened such that the main pipe flow detectors (FM1) and the second flow detector (FM2) record and show the flow of water in the respective pipes or conduits with which they are associated.

To isolate the ion generators (11) from the flow of water to be treated i.e. to take the ion generators "off-line", the second valve (V2) and the third valve (V3) are closed. At this point, the first flow monitor (FM 1) will, indicate or read that there is no flow of liquid in the pipe with which it is associated.

The liquid or water within the ion generators (11) is subsequently drained by the combined opening of the fifth valve (V5), which lets in air and the fourth valve (V4), which leads to a drain (40).

Once the third flow monitor (FM3) associated with the drain outlet (40) indicates that there is no more flow, the ion generators (11 ) will be taken to have been drained and the fourth valve (V4) will subsequently close. At this point, the fifth valve (V5), which allows air in, remains open.

The sixth valve (V6) is then opened, at which point a cleaning agent, for example, acetic acid stored within a suitable reservoir (31) is pumped by pump (30) from the reservoir through an inlet (50) such that the space between the electrodes present within the ion generators (11) is filled up with the cleaning agent.

Once the appropriate amount of cleaning agent has been pumped into the ion generators (11), the sixth valve (V6) is closed, that is, subsequent to the pump (30) associated with the inlet (50) being deactivated or de-actuated.

The cleaning agent is left within the system for a time period required in relation to the time elapsed since the last similar recorded cleaning cycle, size of the system, the type of cleaning agent and concentration used to accomplish the particular cleaning task.

Once a sufficient cleaning time has passed or elapsed, that is, depending on the nature of the deposit to be removed, the fourth valve (V4) is then reopened such that the cleaning agent to which the surfaces of the electrodes within the ion generators (11) has been exposed can be disposed of, or drained from the ion generators via drain outlet (40).

As will be appreciated, the "cleaning cycle" can be repeated, but this time using a different cleaning agent, that is, to remove a different type of deposit from the surface of the electrodes within the ion generators.

Once the system is fully drained of the cleaning agent(s) i.e. flow is no longer detected by the third flow monitor (FM3), the fifth valve (V5) is closed, and the third valve (V3) is re-opened such that water may pass through the third valve (V3) down into the ion generators (11), thereby cleaning or rinsing the electrode surfaces of the ion generators (11). The rinsing water will pass out through the fourth valve (V4) via the drain outlet (40). Once a sufficient time has passed or elapsed, the fourth valve (V4) is closed, and second valve (V2) is re-opened, and finally, the first valve (V1) is closed such that the water from the water supply or reservoir to be treated passes directly and solely through the ion generators (11), the electrode surfaces of which have been cleaned.

As will be appreciated, it is preferable that the above sequence of events is fully automated via the control of a computer system. However, it is to be understood that the steps could be carried out manually by the manual actuation of the various valves, pumps etc.

As will be appreciated, in the absence of the present cleaning system (10), the ion generators (11) would need to be removed from the water supply system, such that the surfaces of the electrodes present on their internal surfaces can be suitably cleaned to remove scale and other deposits common to-,the water supply, which had built up over time.

Although the cleaning system of the present invention has been described for use in cleaning an ion generator, namely, the flow cells thereof which included the electrodes, it is to be understood that the cleaning system can be used to clean any internal surface, for example, the interior surface of a pipe, within a fluid carrying system.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

Claims:

1. A cleaning system for use in cleaning an electrode of an ion generator in situ, the system comprising: an isolator, which when actuated, isolates the ion generator from the fluid supply it is treating; and an inlet through which a cleaning agent can be dispensed into the ion generator such that the electrode of the ion generator is exposed to the cleaning agent.

2. The cleaning system of claim 1, wherein the isolator includes at least two valves, one located at either side of the ion generator.

3. The cleaning system of claim 1, wherein the system further includes at least one reservoir which stores the cleaning agent.

4. The cleaning system of any one of the preceding claims, wherein the system further includes at least one pump for dispensing the cleaning agent through the inlet.

5. The cleaning system of any one of the preceding, wherein the cleaning agent is selected from the group consisting of an acid or a surfactant.

6. The cleaning system of claim 5, wherein the acid is an organic acid, preferably selected from the group consisting of acetic acid (CH₃COOH), benzoic acid (C₆H₅COOH), or is an inorganic acid, preferably selected from the group consisting of Muriatic acid or hydrochloric acid (HCI)

7. The cleaning system of claim 5, wherein the surfactant contains sodium acrylate-silicate ester, acrylate-silicate ester, sodium 2-ethylhexyl sulphate (CsHi₇NaSO₄) and/or sodium dimethylbenzene sulfonate in various concentrations based on the particular cleaning requirements.

8. The cleaning system of any one of the preceding claims, wherein the system further includes a detector for detecting that the isolator has isolated the ion generator from the fluid supply it is treating.

9. The cleaning system of claim 8, wherein the detector includes a flow meter or flow switch.

10. The cleaning system of any one of the preceding claims, further including an outlet through which the system can be drained.

11. The cleaning system of claim 10, wherein the outlet is associated with a detector for detecting the flow of fluid to the outlet.

12. The cleaning system of claim 11 , wherein the detector is a flow meter or flow switch.

13. The cleaning system of any one of the preceding claims, further including a second inlet through which air can be introduced into the ion generator.

14. The cleaning system of claim 13, wherein the inlet includes a valve, which, when actuated, allows air to be introduced.

15. The cleaning system of any one of the preceding claims, wherein the cleaning system further includes a rinser, which when actuated, introduces water into the isolated ion generator such that any cleaning agent can be rinsed from the electrode surfaces.

16. The cleaning system of claim 15, wherein the rinser includes at least one valve for introducing rinsing fluid into the ion generator.

17. The cleaning system of any one of the preceding claims, wherein the system is fully automated.

18. An ion generator in communication with a cleaning system as claimed in any one of the preceding claims.

19. The use of a cleaning system as claimed in any one of claims 1 to 17 to clean an ion generator.

20. A method for cleaning the electrode of an ion generator in situ utilising the cleaning system of any one of claims 1 to 17, the method comprising the steps of: actuating the isolator such that the water to be treated no longer flows through the ion generator; draining the ion generator; and introducing at least one cleaning agent through the inlet, such that the electrodes of the ion generator are exposed to the cleaning agent.

21. The method of claim 20, further including the steps of: draining the at least one cleaning agent through the outlet.

22. The method of claim 21, further including the step of rinsing the surfaces of the electrodes, before the ion generator is exposed to the fluid supply it is to treat.

23. The method of claims 20 to 22, wherein the method is fully automated.

24. A cleaning system substantially as hereinbefore described with reference to the accompanying drawing designated as Figure 1.

25. A method of cleaning an ion generator substantially as hereinbefore described with reference to Figure 1.