| JP3799026 | ALKALI CLEANER |
| JP2010274622 | FILTER CLEANING METHOD |
| JP2002100598 | DEVICE AND METHOD FOR TREATING WAFER AND PRODUCTION METHOD FOR LIQUID CRYSTAL DISPLAY DEVICE |
SZILI, Endre J. (Mawson Institute, University of South AustraliaMawson Lakes Campu, Mawson Lakes South Australia 5095, AU)
LEE, WahTong (38 Anderson Street, Thebarton, South Australia 5031, AU)
LEE, Susan Peck Yok (38 Fouth Avenue, St Peters, South Australia 5069, AU)
KUMAR, Sunil (Mawson Institute, University of South AustraliaMawson Lakes Campu, Mawson Lakes South Australia 5095, AU)
SZILI, Endre J. (Mawson Institute, University of South AustraliaMawson Lakes Campu, Mawson Lakes South Australia 5095, AU)
LEE, WahTong (38 Anderson Street, Thebarton, South Australia 5031, AU)
LEE, Susan Peck Yok (38 Fouth Avenue, St Peters, South Australia 5069, AU)
| CLAIMS 1. An apparatus adapted for the treatment of an article in contact with an electrolyte, by the combined application of electrolytic and ultrasonic energy, including: at least one cathode; at least one anode, wherein a current flows through said electrolyte between said anode and said cathode; at least one ultrasonic generator adapted to emit an ultrasonic signal within said electrolyte; wherein said electrolytic and ultrasonic energy is controllably applied to said article; and wherein the apparatus is adapted to allow the polarity of the anode and cathode to be periodically reversed. 2. An apparatus as in claim 1 , wherein the activity of said ultrasonic generator and said cathode and anode are controlled independently. 3. An apparatus as in claim 1 , wherein said article is electrically conductive. 4. An apparatus as in claim 1 , wherein said article is electrically non-conductive. 5. An apparatus as in claim 4, wherein said electrically non-conductive article is suspended within said electrolyte. 6. An apparatus as in claim 1 , wherein said apparatus is used to clean a wine barrel having a restricted opening. 7. An apparatus as in claim 6, wherein said apparatus includes a first and a second probe adapted to fit through said restricted opening. 8. An apparatus as in claim 7, wherein said first probe is configured to act as an ultrasonic generator and a +ve electrode, said second probe is configured to act as an ultrasonic generator and a -ve electrode. 9. An apparatus as in claim 7, wherein said first probe is configured to act as an ultrasonic generator and a -ve electrode, said second probe is configured to act as an ultrasonic generator and a +ve electrode. 10. An apparatus as in claim 1 , wherein said electrolyte is selected from water or an alkalinalide salt. 11. An apparatus as in claim 1 , wherein said electrolyte is selected from water or a non alkalinalide salt. 12. An apparatus adapted for cleaning conductive articles by the combined application of electrolytic and ultrasonic energy wherein said apparatus includes: a cleaning vessel having associated therewith means for supporting an article to be cleaned and means for the supply of pulsed electrical power to the article to be cleaned to thereby effect an electrolytic cleaning process; and an ultrasonic generator to thereby effect an ultrasonic cleaning process for the supply, wherein the electrolytic cleaning process and the ultrasonic cleaning process are controlled independently. 13. An apparatus as in claim 12, wherein the means for the supply of pulsed electrical power includes a conductor cable extending around a periphery of the vessel, the conductor being attachable to a connector to which a work support is attached, said work support, in turn, being attachable to said article to be cleaned. 14. An apparatus as in claim 13, wherein said connector includes a pin receivable in a socket in said vessel, said socket being electrically connected to said conductor. 15. An apparatus as in claim 1 or claim 12, wherein the apparatus includes a safety shut off mechanism designed to detect a short circuit condition. 16. An apparatus as in claim 1 or claim 12, wherein the apparatus includes a feedback control mechanism designed to provide an optimal current and voltage condition. 17. An apparatus as in claim 1 or claim 12, wherein the apparatus includes a feedback control mechanism designed to provide an optimal ultrasonic agitation condition. 18. An apparatus as in claim 1 or claim 12, wherein the apparatus includes a feedback control mechanism designed to provide an optimal ultrasonic agitation and electrolytic condition. 19. An apparatus as in claim 3, wherein said conductive article is suspended from or connected to the cathode. 20. An apparatus as in claim 4, wherein said non-conductive article is suspended adjacent to the cathode. 21. An apparatus as in claim 3, wherein said conductive article is suspended from or connected to the anode. 22. An apparatus as in claim 4, wherein said non-conductive article is suspended adjacent to and the anode. 23. A method for treating an article including the steps of: placing said article in an electrolyte; applying electrolytic energy to said electrolyte; applying ultrasonic energy to said electrolyte; wherein the production of said electrolytic and ultrasonic energies are controlled to thereby treat said article, and wherein the polarity of the electrolytic energy is periodically reversed. 24. A method as in claim 23, wherein the production of said electrolytic and ultrasonic energies is controlled independently. 25. A method as in claim 23, wherein the electrolytic energy is applied at a potential of between 8 and 18 Volts. 26. A method as in claim 23, wherein the polarity of the electrolytic energy is reversed at an interval of between 10 and 50 seconds. 27. A method as in claim 23, wherein the polarity of the electrolytic energy is reversed between 2 and 10 times. 28. A method as in claim 23, wherein: the electrolytic energy is applied at a potential of between 13 Volts; the polarity of the electrolytic energy is reversed at an interval of 30 seconds; and the polarity of the electrolytic energy is reversed 5 times. |
FIELD OF THE INVENTION
The present invention relates to an apparatus useful for cleaning a surface using the combined effects of electrolysis, ultrasonics and disinfection. The surface cleaned by the apparatus and method of the invention may either be electrically conductive material, such as metal, or non-electrically conductive material, such as plastic or wood.
BACKGROUND OF THE INVENTION Ultrasonic cleaning is used in numerous applications for sterilising and cleaning surfaces. Ultrasonic baths are widely used in the cleaning of small articles such as rings and other jewellery articles. These articles are often small and have complex surface geometries that make simpler washing processes such as hand scrubbing and spray washing less effective. For example, crevices may be inaccessible by a simple washing process. Also, jewellery items are often relatively delicate and are not suited to harsh physical cleaning treatments that may scratch or otherwise damage the surface. This applies to other metal surfaces to be cleaned. Ultrasonics are also used in cleaning the interior surface of wine barrels.
Ultrasonic cleaning is the introduction of high-frequency sound waves into a liquid, usually between 20 to 80 kHz. The resulting action is called "cavitation".
Cavitation is created by high and low pressure areas produced in the solution as the sound waves pass through it. In low-pressure areas, microscopic vapour bubbles form. The pressure rises rapidly as the next sound wave passes through the area, violently imploding the minute bubbles and releasing the energy that does the cleaning. At 20 kHz, this is happening 20,000 times per second. The resulting cleaning action is very effective on those parts of the article that are directly in the line of sight of the sound wave although less so on those parts of the article that are less exposed to the ultrasonic action.
An alternative method of cleaning is the use of electrolysis. During typical operation of an electrolysis cell, an electric current is produced and hydrogen and oxygen are produced at the negative (cathode) and positive (anode) electrodes, respectively, which typically are metal plates positioned in a selected electrolyte. The hydrogen and oxygen thus produced may be captured and used as desired, or may be discarded, depending on the particular application.
Many different electrolysis systems are known, but typically, a pulsating DC voltage is generated and applied to the electrodes. The signal has particular characteristics with values selected such that hydrogen is produced at the cathodic portion of the electrode. The article to be cleaned is attached to and forms a part of the cathode and whilst the current is maintained rapidly acquires a coating of small hydrogen bubbles. The article at the cathode undergoes a process of cathodic reduction and any detritus or oxide material on the surface of the metal is rapidly reduced to the point where it is readily removed from the article.
There exist various prior art cleaning processes which involve cycling between electrolysis and ultrasonics. As mentioned above, these processes rely on either removing oxidised surfaces, or on hydrogen bubbles, often using common surfactants (eg detergent) as the cleaning fluid medium .
A problem with these existing techniques however is that cleanliness to nano- millimetre resolution is not typically achievable. Bovine (protein) solution for example, which has exceptionally high surface bonds, is typically not able to be removed by any single electrolysis anodic or cathodic polarity. The present invention is directed to a method and apparatus that is able to combine the effects of ultrasonics, electrolysis and disinfection to remove solutions having extremely high surface bonds.
SUMMARY OF THE INVENTION
It has discovered that the effect of periodical polarity reversal produces an improvement in the level of cleanliness achieved.
Preferably the duration of polarity reversal between positive and negative may be variable as may the applied current and/or voltage.
The process and apparatus of the invention has been developed with a view to the removal of resistant proteins, for example bovine proteins and prions from contaminated surfaces. The removal of such proteins is of concern because of the apparent strength of the bonds between these materials and surfaces, particularly metal surfaces. While not wishing to be bound by any theory, it is suggested that the use of intermittently reversed polarity proposed offers a method of synergistically promoting the ultrasonic cleaning action, and promotes disassociation of the protein surface bond. Therefore, in one form of the invention there is provided an apparatus adapted for the treatment of an article in contact with an electrolyte, by the combined application of electrolytic and ultrasonic energy, including:
at least one cathode;
at least one anode, wherein a current flows through said electrolyte between said anode and said cathode;
at least one ultrasonic generator adapted to emit an ultrasonic signal within said electrolyte;
wherein said electrolytic and ultrasonic energy is controllably applied to said article; and wherein the apparatus is adapted to allow the polarity of the anode and cathode to be periodically reversed.
Preferably, the activity of said ultrasonic generator and said cathode and anode are controlled independently.
Preferably, said article is electrically conductive.
Preferably, said article is electrically non-conductive. Preferably, said electrically non-conductive article is suspended within said electrolyte.
Preferably, said apparatus is used to clean a wine barrel having a restricted opening.
Preferably, said apparatus includes a first and a second probe adapted to fit through said restricted opening.
Preferably, said first probe is configured to act as an ultrasonic generator and a +ve electrode, said second probe is configured to act as an ultrasonic generator and a -ve electrode. Preferably, said first probe is configured to act as an ultrasonic generator and a -ve electrode, said second probe is configured to act as an ultrasonic generator and a +ve electrode.
Preferably, said electrolyte is selected from water or an alkalinalide salt. Preferably, said electrolyte is selected from water or a non alkalinalide salt.
In a further form of the invention there is provided an apparatus adapted for cleaning conductive articles by the combined application of electrolytic and ultrasonic energy wherein said apparatus includes:
a cleaning vessel having associated therewith means for supporting an article to be cleaned and means for the supply of pulsed electrical power to the article to be cleaned to thereby effect an electrolytic cleaning process; and
an ultrasonic generator to thereby effect an ultrasonic cleaning process for the supply, wherein the electrolytic cleaning process and the ultrasonic cleaning process are controlled independently. Preferably, the means for the supply of pulsed electrical power includes a conductor cable extending around a periphery of the vessel, the conductor being attachable to a connector to which a work support is attached, said work support, in turn, being attachable to said article to be cleaned.
Preferably, said connector includes a pin receivable in a socket in said vessel said socket being electrically connected to said conductor.
Preferably, the apparatus includes a safety shut off mechanism designed to detect a short circuit condition.
Preferably, the apparatus includes a feedback control mechanism designed to provide an optimal current and voltage condition. Preferably, the apparatus includes a feedback control mechanism designed to provide an optimal ultrasonic agitation condition.
Preferably, the apparatus includes a feedback control mechanism designed to provide an optimal ultrasonic agitation and electrolytic condition. Preferably, said conductive article is suspended from or connected to the cathode.
Preferably, said non-conductive article is suspended adjacent to the cathode.
Preferably, said conductive article is suspended from or connected to the anode.
Preferably, said non-conductive article is suspended adjacent to and the anode.
In yet a further form of the invention there is provided a method for treating an article including the steps of:
placing said article in an electrolyte;
applying electrolytic energy to said electrolyte;
applying ultrasonic energy to said electrolyte;
wherein the production of said electrolytic and ultrasonic energies are controlled to thereby treat said article, and wherein the polarity of the electrolytic energy is periodically reversed.
Preferably, the production of said electrolytic and ultrasonic energies is controlled independently.
Preferably the electrolytic energy is applied at a potential of between 8 and 18
Volts. Preferably the polarity of the electrolytic energy is reversed at an interval of between 10 and 50 seconds.
Preferably the polarity of the electrolytic energy is reversed between 2 and 10 times.
In preference the electrolytic energy is applied at a potential of between 13 Volts; the polarity of the electrolytic energy is reversed at an interval of 30 seconds; and the polarity of the electrolytic energy is reversed 5 times. DESCRIPTION OF DRAWINGS
The above and other objects, features, and advantages of the present invention will be apparent from the following detailed description of a preferred embodiment in conjunction with the accompanying drawings. In the drawings: Figure 1 illustrates a cleaning apparatus in accordance with a first
embodiment of the present invention;
Figure 2 illustrates in cross sectional view a detail of the apparatus of Figure
1 in a first position;
Figure 3 illustrates in cross-sectional view a detail of the apparatus of Figure
1 in a second position;
Figures 4a, 4b & 4c illustrate schematically how the apparatus of the invention operates;
Figure 5 illustrates schematically an apparatus in accordance with a second embodiment of the invention; Figure 6 illustrates in cross-sectional view an apparatus in accordance with a third embodiment of the invention;
Figure 7 illustrates in cross-sectional view an apparatus in accordance with a fourth embodiment of the invention; and
Figure 8 illustrates in cross-sectional view the apparatus of Figure 7
including a shield.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The following detailed description of the invention refers to the accompanying drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts. Shown in Figure 1 is an apparatus 10 constructed in accordance with the present invention. The apparatus 10 is thus adapted to perform both an electrolytic cleaning function and an ultrasonic cleaning function. The apparatus 10 includes a bath 12 having a work supporting bar 14 suspended over the bath 12, electrical connectors 16 attached to the bar 14. Not shown in the drawings are a source of direct current electrical power and an ultrasonic generator 18.
The bath 12 is generally rectangular, although it will be appreciated that any shape of bath could be used and that the dimensions of the bath are more dependent on the geometry of the article to be cleaned than on any specific physical requirements. The bath 12 is a double skinned bath and thus has an interior volume 20 than can conveniently house the ultrasonic generator 18 and other functional parts. Importantly around an upper periphery of the bath and within the cavity 20 is an electrical conductor 22. The conductor 22 is connected to the DC power supply.
In the embodiment under consideration the work supporting bar 14 extends diagonally across the bath 12. At each end the work supporting bar 14 is attached to a respective electrical connector 16. As shown in Figures 2 and 3 the electrical connectors 16 are in electrical contact with the conductor 22 and thus the DC power supply.
The electrical connectors 16 each consist of a pin element 24 that extends through and forms an electrical contact with the work supporting bar 14. The pin elements 24 have a generally vertically arranged split 26 therein and an upmost insulating sheath 27.
The pin elements 24 are each received in a respective connector 28. The connector 28 incudes an outermost electrically insulated nut 30 and an axial conductive tube 32. The conductor 22 is attached to a lower end of the tube 32. The pin 24 is received in the tube 32 and by splaying the pin about the split 26 a secure electrical contact to the tube 32 and thus to the conductor 22 is assured. The drawings in Figures 2 and 3 illustrate how easily the work supporting bar 14 can be disconnected from the conductor 22 simply by grasping the sheath 27 and lifting the pin 24 out of the connector 28.
Articles to be cleaned, for example, rings 34, are suspended by a conductive wire from the work supporting bar 14. In use, the apparatus 10 is provided with a control unit (not shown) that controls the operation of the unit and permits all of the functions of the unit to be controlled independently. The controller allows:
• Programmable power levels and duty cycles for electrolysis.
· Programmable power patterns (powers and duty cycle) for ultrasonic cleaning.
• Programmable degassing process.
• Programmable polarity reversal
• Programmable cut-out temperature for tank temperature.
• Digital display and audible beeper to show the current operational status of the cleaner.
• Operator alerted power failure during a cleaning or degas process detection.
• Operator alerted electrolysis overload detection
• Operator alerted over temperature detection and
• Internal cooling control of electronics. The apparatus 10 can thus operate independently as an ultrasonic
cleaning unit, an electrolytic cleaning unit or in combination.
Electrolytic cleaning is achieved by applying a pulsating DC current to the unit. Typically, the device is wired such that the article to be cleaned is the cathode and the bath 12 is wired as the anode. Hence, during
electrolysis hydrogen generated will accumulate around the article. A
simplified illustration of this process is shown in Figures 4a, 4b and 4c. The article 34 has attached thereto dirt or metal oxide or other material to be removed 36. The bubbles 38 generated in the electrolytic cleaning process are generated around all of the surfaces of the article 34 and, importantly, at the surface of the article, that is, between the article and the surface
contaminant. The bubbles 38 therefore serve to partially dislodge the
contaminant 36 from the article 34 as illustrated in Figure 4b.
The ultrasonic process dislodges the dirt or surface contamination 36, as a result of mechanical interference, further lifting it completely from the
surface of the article. It also aids in the dispersion of the bubbles 38 so that the article 34 is not insulated against further electrolysis. It has been found that applying simultaneously ultrasonics and electrolysis in a controlled manner yields exceptional cleaning results. In particular, it has been found that reversal between positive and negative during electrolysis, and regulation of the reversal between each positive and negative charge from milliseconds to several seconds, and between millivolts and milliamps to several volts and amps, combined with high frequency ultrasonics, achieves a most effective and efficient cleaning and disinfection result.
High frequency ultrasonics has been used traditionally to remove foreign soil in a suitable liquid medium. The cleaning method according to the present invention, whereby ultrasonic energy propagation is controlled, induces a well controlled broadband width acoustic energy. The alternating positive and negative polarities combined with a broad bandwidth of high frequency acoustics, results in extreme hydraulic microscopic activity which neutralises foreign soil to lose its electrolytic bond to the substrates.
In controlled conditions, that is, without any oxidation or imperfections in the substrate, there has been no evidence of changes to topography or mechanical properties. The combination of electrolysis and ultrasonics is thus effective in removing protein and soil from the surface. In summary, by correctly positioning two electrodes in the bath 12, radiating ultrasonic sources, and charging and alternating the cathodic and anodic electrodes, bonding of the foreign soil from the non-conductive substrate is neutralised and the foreign soil is removed.
The applied electrolysis electric current can be varied from an alternating current to a direct current, at combinations of duty cycle configurations, providing the necessary changes to the electric fields. The configurations include pulsing from hertz to kilohertz in alternating and direct current modes.
Not illustrated but also included in the control module is a short circuit safety device. In the event that two or more of the items in the bath 12 touch one another thereby causing a short circuit the safety device will operate to cut off power. Typically the electrolytic cleaning will be carried out in 60 second cycles.
For example, electrolysis may occur from 20 seconds up to 60 seconds in a 60 second cycle. The duty cycle rate may be varied between three ranges in a stepped fashion. It is, of course, important to note that these ranges are selected arbitrarily and that any given article to be cleaned and indeed any cleaning apparatus may have entirely different duty cycles.
Similarly, the power level during electrolytic cleaning may be increased in fractions from 2/10 to max 10/10 in 5 simplified increments. Each power level is divided into 5 millisecond increments. It is possible to step through and select any duty cycle and power levels and combine these two
configurations.
With "ultrasonic power patterns" one can select power levels 1 , 2 or 3 and duty cycle 25%, 50% or 75%, and then combine the electrolytic and ultrasonic cycles. Separate electrolysis power patterns and ultrasonic power patterns may be operated or it is possible to combine these two configured process
simultaneously.
Aside from the use of electrolysis power pattern a preset power of Watts could be used to allow the patterns for electrolysis and ultrasonic to be configured. The use of constant fixed voltage will reach a limitation of maximum optimum power, given a constant conductivity of cleaning fluid, temperature and electrodes (-ve electrode substrates of parts and the +ve electrode the tank). To extend this power (given the rest of the variables being the same) one can step into higher voltages eg up to say 24 Volts. This requires a feedback control to be installed into the circuit to provide the necessary control to give the nominated power output.
For removal of contaminants with exceptionally high surface bonds such as bovine protein further control of electrode power is used. Pulses in the order of 500 Volts, lasting for micro seconds neutralize the magnetic or bond memory of the contaminants, allowing them to be removed by the ultrasonic action.
Below are the methodologies for electrolysis and ultrasonic
configurations each separately or both simultaneously: 1 . Monitor the electrolysis current to switch to the correct electrolysis power pattern or the ultrasonic power pattern.
2. Switch both on simultaneously self-configuring optimum electrolysis power patterns and ultrasonic power pattern
3. Switch on/off self-configuring alternating between electrolysis power patterns and ultrasonic power pattern
The above 3 possible process can be dependent on fluid conductivity, fluid temperature and conductivity of the part substrate. These three variables will change during the cleaning cycle. An alternative form of the invention is illustrated in Figure 5. This illustrates the usefulness of the conductor 22. In this case a multiple of work support bars 14 are each connected through two respective connectors 16 configured as previously described. The unit thus has a great degree of flexibility as to the size and disposition of articles placed with the bath. In yet a further alternate embodiment as illustrated in Figure 6 the apparatus 10 can be in the form of a bath 12 for use in relation to cleaning non-conductive surfaces. The bath 12 includes a conductive insert 40 and an outer non-conductive housing 42 as is well known in the art. A clamp 44 which is connected to a power source (not shown) by way of cable 46 is connected to conductive insert 40. In the present embodiment the conductive insert 40 acts as the anode for electrolysis. A probe 48 which is connected to a power source (not shown) by way of cable 50 is suspended in the bath 12 which contains electrolyte 52. Probe 48 is configured to act as a cathode. The non-conducting articles 54 which are being cleaned are placed within tray 56 which is suspended within electrolyte 52. An ultrasonic generator 18 which is connected to a power source (not shown) by cable 58 is also placed within the bath 12.
The process of electrolysis which results in a flow of ions between the cathode 48 and anode 40 results in the production of free radicals 60. Free radicals 60, such nascent oxygen, are toxic to living organisms and consequently bacteria and other harmful organisms which are in contact with electrolyte 52 are eradicated. In addition, to assist the formation of free radicals 60, chemicals such as chlorine (CI) and hydrogen peroxide (H 2 0 2 ) may be added if suitable.
To assist in the cleaning and disinfection of electrically non-conductive porous material, metallic particles that are known to be harmful to bacteria, such as silver, can be added to the electrolyte 52. These metallic particles are dispersed by the action of the ultrasonic generator 18 and assist in disinfecting the surface being cleaned. This would be particularly useful on articles used in the medical field or in food storage and preparation.
The apparatus 10 can be further used for cleaning containers such as wine barrels 62. As illustrated in Figure 7, wine barrels 62 typically include wooden staves 64, metal bands 66 and bung holes 68. The interior surfaces of wine barrels 62 are electrically non-conductive. Consequently, both an anode and a cathode must be inserted into the electrolyte 52 to undertake electrolysis. As illustrated in Figure 7, probes 70 and 72 are inserted through bung hole 68. Probe 70 is connected to a power source by cable 46 and is configured to act as the anode for electrolysis. The probe 72 is connected to a power source by cable 50 and is configured to act as the cathode. In this manner, free radicals 60, which are toxic to living organisms, are able to be formed within the electrolyte 52. Because ions will typically find the shortest or least resistive path between the anode and cathode the probes 70 and 72 include insulation 74 which prevents the flow of ions in close proximity to the bung hole 68 where the distance between the probes 70 and 72 is the least. The probes 70 and 72 are also adapted to act as ultrasonic generator and are connected to ultrasonic generators (not shown) by cables 56. As the reader would now appreciate, the probes 70 and 72 are configured to both produce free radicals 60 and disperse them throughout the wine barrel 62.
The apparatus, as illustrated in Figure 8, further includes a shield 76 adapted to restrict the current flow and movement of free radicals 60 within the cleaning fluid 52. The ions will find the shortest or least restrictive path between the anode probe 70 and the cathode probe 72 and consequently the shield 76 ensures that the flow indicated by arrows 78 is diverted from a direct path to ensure the barrel 62 is sufficiently cleaned. It is well known that the more material that is suspended in the electrolyte 52 the more conductive the fluid will become. Therefore as the reader would appreciate, the longer the cleaning is undertaken the more effective the electrolysis will be. Consequently, as the electrolyte 52 becomes more saturated with suspended material and the effectiveness of the ultrasonic generator 18 is reduced, the efficiency of the electrolytic cleaning function increases.
Chemicals may also be added to improve conductivity of the electrolyte 52, for instance, salt, sugar or detergent could be added to increase the efficiency of the electrolysis. This would be particularly useful when cleaning articles such as containers used for transporting organs.
In effect, where the item being cleaned is electrically conductive, electrolysis strips material and creates free radicals 60, whilst the ultrasonic generator 18 acts to clean and disperse the free radicals 60 within the bath 12. In the situation where the article being cleaned is electrically non- conductive, electrolysis creates free radicals 60 which are dispersed by the action of the ultrasonic generator 18. The ultrasonic generator 18 further acts to clean the electrically non-conductive article. As the reader would appreciate the dual action of electrolysis and ultrasonics produces a more efficient cleaning apparatus.
The following method has been proven completely effective in removing proteinaceous contamination from surgical stainless steel. The item to be cleaned is attached to an electrode in an electrolytic bath of 0.1 % NaCI. The item is sonicated whilst the electrode is first polarised to a positive polarising voltage for a first polarising time. The electrode is then polarised to a negative polarising voltage for a second polarising time. This sequence is repeated a number of cycle times. The polarising voltage can vary between 8 and 18 volts, the first and second polarising time can vary between 10 and 50 seconds and the number of cycles can vary between 1 and 5 cycles. A combination of 3 cycles of 30 second first and second polarising times with a 13 Volt first and second polarising voltage has proven most effective.
The reader would appreciate that the present invention has many applications for cleaning electrically conducting and electrically non- conducting material. The invention could also be used to sterilise bodies of fluid such as wine or water in fish ponds. The present invention has many advantages over the prior art by combining the effects of electrolysis and ultrasonics. The combination of these two processes enhances each
individual method, for instance, the free radicals 60 produced by electrolysis are dispersed by the action of ultrasonic generator 18. Consequently, the present invention increases the effectiveness of the individual techniques.
Furthermore, where the water includes large quantities of particles in
suspension and hence the effectiveness of the ultrasonic activity may be reduced, electrolysis will be more efficient.
Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.
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