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Dear all,
I have recently come across some Japanese make Electrostatic oil cleaning system.I works on following principle:
Oil(contaminated) is passed through high voltage which charges the suspended dirt particles, and charged particles are pushed towards positive and negative electrodes. In the process contaminants get entrapped in collecter medium and thus all particles even of submicronic size is removed from oil.
Mainly used for any oil of less than 220 cst., specially popular in hydraulic oil case.
Now, the manufacturer claims that after cleaning the oil from this filtration system and adding 10% of fresh charge, same oil can be used for forever by repeating the same process.
Please let me know if somebody have come across this type of filtration system, and what would be the effect on oil after few repetetive cleaning cycles.As according to me after continuous use,depetion in additive package can't be make up by adding onle 10% of fresh charge.
Pl. give comments on any aspect of this particular system.

Regards
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Hi Dipen,
A couple of things to remember is that not all oils are full of additaves that get used up. I will speak in generalities here but for my industry I rarely condemn an oil because the additave package has been depleated to the point where it has to be replaced. Since we implemented oil changes based on condition (condition based maintenance) several years ago. We have had some applications that have lasted for 5+ years without an oil change. Our oils are normally changed out because of contamination ingress or generation, some contaminents are not easily filtered out. Rarely do we change the oil because of oxidation by-products the real selling attribute of the electrostatic systems.
These types of systems make sence for some industries, (you mentioned hydraulics-- where sludge and varnish are REAL issues) I have not found the need in my field.
I get suspicious when someone claims that they can selectively charge particles that are contaminents or wear when some of the contaminents can actually be additaves in other lubricants.
regards.....
Electrostatic filters are great things but they operate very slowly and lose effectiveness as moisture content rises. There are some reports that electrostatic filtration will remove bi-products of oxidation and can filter to well beloew 0.5 microns. There are some plastic injection mouldings machines that actually use electrostatic filtration (I think, but don't quote me, Kawaguchi are one). As for the additives, in my opinion, they can cause more problems then if they were absent. But if you know what you are doing, sweetening the oil with new additives can be effective for life extension, although I would advise extreme caution with this approach.
Oils theoretically could last forever in the right conditions. But in my opinion, there are too many factors such as oxidation that cause a chemical breakdown of the oil. So you can keep removing the contamination but eventually, there will be none left.
Electrostatic oil cleaners are excellent contamination control devices for some applications. You seem to have a good grasp of the basics. As one post pointed out, they excel in areas where degradation mechanisms are at play causing deposits.

Although they do not work well in the presence of water, you will have much more urgent concerns if you have a high water content in your oil. Electrostatic oil cleaners continue to work well again once your water problem is under control.

But, no contamination control device will take the place of oil analysis and conditioned-based oil changes.

Finally, I encourage you to read some of Dr. Sasaki's papers and research on electrostatic oil cleaning for additional information. He has done exhaustive research on the subject and his findings have been widely published.
The concept of agglomerating particles through an electric field was first developed in Japan in the mid-1970’s. A high DC charge was passed through the oil, quickly agglomerating the particles and significantly improving the efficiency of filters. Particle agglomeration often occurs when energy is imparted onto fluid, but quickly dissipates when the energy source disappears. Since a high charge was used, the oils became very clean, very quickly. Although this technology was patented, a commercial product was never developed because the scientists could not figure out a method to safely do this to oil without a chance of additional problems occurring. The applied charge remained on the particles to keep them combined together well after the fluid passed over the electrodes. This creates a host of potential problems, such as erratic, unpredictable particle agglomeration in unwanted areas of the lubrication system, or accelerated oil oxidation. Of even greater concern is a release of the accumulated charges in the form of a spark causing safety issues.

"Balanced Charged Agglomeration" is not a science definition but a marketing term. Although it is foreseeable that this technology could be applied in a range of other markets, I believe that significantly more research needs to be done on the technology before it can safely be applied to lubricants.

Before you purchase the technology, read some independent scientific papers and consult with your oil supplier.

Smile
quote:
Originally posted by Dipen:
Dear all,
I have recently come across some Japanese make Electrostatic oil cleaning system.I works on following principle:
Oil(contaminated) is passed through high voltage which charges the suspended dirt particles, and charged particles are pushed towards positive and negative electrodes. In the process contaminants get entrapped in collecter medium and thus all particles even of submicronic size is removed from oil.
Mainly used for any oil of less than 220 cst., specially popular in hydraulic oil case.
Now, the manufacturer claims that after cleaning the oil from this filtration system and adding 10% of fresh charge, same oil can be used for forever by repeating the same process.
Please let me know if somebody have come across this type of filtration system, and what would be the effect on oil after few repetetive cleaning cycles.As according to me after continuous use,depetion in additive package can't be make up by adding onle 10% of fresh charge.
Pl. give comments on any aspect of this particular system.

Regards


Dear Dipen

I have been offering Oil Cleaning Services to many Plastic Items manufacturing Units with Off Line Mechanical Filtration Unit fitted with Laser Particle Counter and it cleans the Oil up to required Oil Cleanliness level Automatically and prit out the report indicating Oil Cleanliness level before and After Filtration. This report indicates Particle Count of each range ( 5 to 15, 15 to 25, 25 to 50, 50 to 100 and > 100 ) and also indicates oil cleanliness level in terms of NAS / ISO.
As per my experience Electrostatically Oil Cleaning is normally known as Bleed and Feed Type Filtration. That means when you filter the Oil Additives are also removed along with contaminants and you need to replenish it. Unless you have a right source of this additive supplier you should not add such additive peckage with out full information. This may damage the Oil. I therefore strongly recommond you to use Mechanical Filters and get the Oil Cleanliness level within the prescribed Oil Cleanliness level only. Do not Polish the Oil.

V.S.Dave
Dipen,

My experience of visiting many user sites of electrostatic filter systems is that the oil life is extended but water and acid in the applications is the limiting factor. In must user manuals water above 400 ppm water or acid above 2 will cause problems. However, I do disgree that these systems strip additives. My recommendation is to buy a dehydrator to use with the electrostatic and monitor TAN acid in oil tests. You do not need to change the oil until the oil analysis indicating negative oil condition. My company can provide the dehydrator or another technology that can handle the water and acid in the same system.
Hi Dipen
The electrostatic cleaning system is safe to use for any length of time.It has no effect on the oil.The process cannot remove any dissolved components of the oil, so additives are not affected.The idea of using oil forever is not entirely wrong, because in a "clean","cool" and "dry" hydraulic system there is no possibility of oil dterioration.

In such cases, 10% addition is sufficient.This is 10% every year, and not just once in a lifetime.This refreshes some additives which deplete by age. The idea is that oxidation is catalysed by metal wear particles in the presence of moisture, and heat.If you remove the causes, like particles by the Electrostatic system, and control your temperature, the oil stays as good as new. Also, the main property of oil, which is viscosity, never changes unless you mix two oils, or oil and water.

Take 10% as the best case, worse cases may require 20%, but if controls are excercised, complete oil changes are never required.

The parameter to check is Total Acid number, and it can be kept under control for years together.
Please clearify my doubt about effect of electric charges on metallic oxides in the form of additives which imparts main properties to the Oil. How they will not be affected ? Can any one through some light on this ?

quote:
Originally posted by Greg Livingstone:
Electrostatic oil cleaning does not remove soluble additives. There is tremendous research backing this up.
There is a reply to the question of removal of metallic oxides here in this forum, by Greg..
The process is Electro STATIC not ElectroLYTIC. Hence dissolved components cannot be affected. In a static field salt will not separate out of water, for instance.

Only particles, being separate from the oil, will be separated out. There is a wealth of trial evidence to prove that dissolved additives cannot be removed. Only "foreign" particles are removed.
Dear Bala,
I have only talked about addition of new oil, from same manufacturer, same specs. Hence the only problem with frequent addition would be overflow of oil, not overdosage of additives.

Your doubt would be valid if I had talked about addition of additive package separately. But that is not the case.

quote:
Originally posted by Bala:
Mukesh,

It's quite obviuous that additives gets depleated over a period of time.Since it's a simple tribochemical reaction,additives will not be completely removed from systems,adding 10% every time may lead to overdosage and subsequently results in other performance problems......

Bala.
Bala, additives deplete over time for many reasons and adding top up oil will help maintain adequate additives in you oil. Since the new oil containes the same amximum ratio of additives this ratio can never be more than it was to start with some will be depleted and the new oil will have the original makeup so the net will always be less than the whole unless you are somehow losing just basestock.
Thanks Mukesh for clarification for Electrostatic and Electrolytic status of salts. Could you please clarify how electostatic cleaning will not be considered as Electrolytic ?
When NaCl is dissolved in water and currant is passed through the solution, NaCl is sepeared out by chemical reaction then why not other salts ( Additives which are similar metallic salts !! ) in similar way ?
Can you clarify the differance between Electrostatic and Electro Lytic solutions ? What is the differance ?

On One hand you say that soluble Additives in the form of salts are there in the oil and oil is chatged with electricity then when you pass electric currant through it why these salts will not be affected ?

I have learned from many users of electrostatic cleaners, that Oil is loosing it viscosity and it becomes thin, could it be because of depleation of any viscosity Index improver ?

quote:
Originally posted by Mukesh:
There is a reply to the question of removal of metallic oxides here in this forum, by Greg..
The process is Electro STATIC not ElectroLYTIC. Hence dissolved components cannot be affected. In a static field salt will not separate out of water, for instance.

Only particles, being separate from the oil, will be separated out. There is a wealth of trial evidence to prove that dissolved additives cannot be removed. Only "foreign" particles are removed.
Dear Dipen,
Now even after some lively discussion,perhaps you have still not got the satisfactory reply,opinions of experts differ in a large way.
Electrostatic cleaners are good as they remove particles even smaller than 1 micron, but even if the moisture in the oil is more than 600 ppm or 0.06 % the cleaning machine will stop. Its Beta ratio is not mentioned as it is very slow.
With regular 10% topping up you cannot continue the same oil for ever with this machine.Moisture present upto 600 ppm in oil itself is harmful and accelerates oxidation deteriorating the quality of oil gradually.
Yes, posting by Samnugger is worth more attention here. Klarol Oil Cleaning System is capable of making the slogan "No More Change of oil" a reality by removing solid particles upto 1 micron and moisture 100%.
Hymat,

You are mixing apples and oranges, all in an effort to undermine usefulness of electrostatic filters, which I see you don’t represent, and which technology is direct competitor to the technology that you are peddling. Your argument by comparing an inorganic salt of a strong acid and a strong base that fully dissociate in water (Na+ and Cl- ions) to stable non-dissociable organic molecules, is completely missing the mark. The fact is that transformer oil has antioxidant additives added to base oil, and is successfully for more than 100 years used as INSULATING fluid in transformers. This is possible because additives dissolved in oil are not dissociating on ions (like the inorganic compound that you offered as an example). Instead, they become a part of hydrocarbon aliphatic or aromatic molecules, and therefore do not conduct electricity.

Also, I have never heard that electrostatic filters affect viscosity in any form or shape. Can you please provide some more info regarding the observed oil thinning that you mentioned in your previous comment?

By the way, I am end user, and don’t represent any company and/or any product, but keep my mind open to learning and evaluating new products and new technologies.

John
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