What's the best way to filter a gear lube that doesn't have any filters? It holds about 20 gallons. Thanks.

Freezer,
I posted this response to a question about filter carts last week. If you would like to discuss it further email me.


I use ofline filtration with good results. In the indusrty I am working in (corn and grain milling) vacuum distillation, air stripping or other methods are not cost effective or convenient as the equipment is very expensive and typically larger and less mobile than a small portable filter. We have alot of conveyors with small sump capacities fronm 2-20 gallons which are often located in places you cannot get a large wheeled cart into without a crane or other rigging. Our sumps are fit with quick connects for the filter units, air filtering breathers and pitot tube sample ports. This allows us to quickly and effectivly attach the filters and monitor particle counts in our onsite lab.

Freezer,
I have some questions first. How many of this same gearbox are in your facility?
You have two options: set up an off line filtration unit or use a filtration cart. The selection depends on cleanliness targets, equipment criticity, number of units.
The selected target can be achieve with both methods.

Freezer,
Any filtration process hase to establish the level and type of contaminant and hence be used to determine the most appropriate responce. Do you have any details?

regards....

We have been researching this area using filter carts for 2 years in a wide range of plants and have seen dissapointing results from normal automotive type oil filters with not been able to filter down clean enough without blocking expensive filters and to prevent the original abnormal wear mode from returning,

we think the reason for this is we are attempting to remove fine contaminating wear debris sized from 0.5-10 µm and these particles sizes are very mobile being affected by moleceular movement as well as oil flow, what appears to be the answer is colealescing filters as these force the the fine contaminating particles into an area that causes them the "clump" together into a larger size that can be caught,

we currently are setting up a carefully evaluation off coalescing filtration over the next two months and will pass on the outcome complete with micro images once we are satisfied with the results.
"colealescing filters" for this use are more refined versions of the the toilet roll principle,
It appear pumping down the end of the roll forces these sized particles together coalescing the fine wear debris into larger clumps more easily removed.

Dear Mr. Freezer:
I am a filtration specialist. For small gearboxes such as this, it is best to use an off-line filter unit with small pump/motor group. This unit is should contain a B1 or B3>1000 absolute rated filter. Unless the ingression rate is excessively high, this will resolve most contamination problems.

Another option is a high speed centrifuge. Centrifuges have exceptional high performance in sub-micronic ranges, but they require pressure between 30-80-psi to insure rotor speed. Secondly, they do not work in high viscous oils.

If you need a source on the off-line filters, please contact me.

freezer,
"best" is subjective...however one consideration is to drain off the oi in the gearbox and let it settle for a day or so. Go back and siphon off the top 4/5ths from the top of the container into a clean container. Add in 4 gallons of new and you are as good (sorry clean) as new. All of the solid contamination will have sank to the bottom along with the free water. Your material cost is ~ 1/5th of the replacement cost. It is also ~ 1/50th the cost of a filter unit (~$1000.)
My opinion is that you would be wasting money in using a very high efficiency filter to clean a gearbox that can normally last for a very long time with a reasonably clean ISO level (18/15/13) Puting a 10 micron beta 2 (nominal)kidney loop system will probably clean up your system over time. These types of filters can be bought for <$5 bucks.

hope this helps....

regards....

I would recommend a small stationary offline unit with a 5 micron(c) Absolute element to obtain a 17/15/12 which is recommended for Industrial Gearboxes.

Normally for viscous gear oils filteration below 25 micron wil not help and higher viscosity of the oil doesn't allow the oil to pass through them and most of the time they will passing thro the bypass.

I would recommend a Roto Clean filter in the kidney loop circuit with layered plates where the filter traps the dirt and contamination and the dirt is wiped off by rotating the core and removed by unscrewing the bottom cup

Hope this helps

My apologies to Mr. Zavier but I disagree with him about not being able to use filtration below 25 micron with gear oils. I regularly use filtration down to 3 microns with great success on gearboxes and achieve target levels of 17/15/13 with ISO VG 220 oils. There are many fine filter units available with high differential pressure heads available to use with high quality filters. If you filter operating equipment that is up to temperature then the oil thins down and you can effictively utilize fine filtration.
Rotary strainers seem to me to represent a pretty old technology that has been greatly improved upon by the quality and availabliity of modern Beta rated filters.

Once again, I agree with BuckHntr. I even filter ISO 320 gear oil down to 5 micron with no trouble, so long as the oil is at operating temperature, 140-160 deg.F.

I agree also we filter 220 gear lube with 3 micron absolute with 14/13/11 results .At start ups with oil at cold temp it is in bypass but as temp rises to 130f to 155f oil is easily filtered .These are 9 and 33 gallon gearboxes .

quote:

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Originally posted by BuckHntr:
My apologies to Mr. Zavier but I disagree with him about not being able to use filtration below 25 micron with gear oils. I regularly use filtration down to 3 microns with great success on gearboxes and achieve target levels of 17/15/13 with ISO VG 220 oils. There are many fine filter units available with high differential pressure heads available to use with high quality filters. If you filter operating equipment that is up to temperature then the oil thins down and you can effictively utilize fine filtration.
Rotary strainers seem to me to represent a pretty old technology that has been greatly improved upon by the quality and availabliity of modern Beta rated filters.

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This issue of how fine can one filter is right on the top of my "wondering" list.
I have had discussions with Pall Australia about filters for a 500 Hp ball mill gearbox and they say that the EP additives (long molecular chains) in gear oil blocks fine filters and have recomended 12 micron as the finest filter practical. This is in the knowledge that the biggest life extension requires 3 micron filters or less. Maybe fine filters only work well without EP additives present and maybe you guys using fine filters are filtering out your EP additives. Have you checked for the correct EP additives in your oil analysis reports.

quote:

Originally posted by Bert A. Hibl:
Dear Mr. Freezer:
I am a filtration specialist. For small gearboxes such as this, it is best to use an off-line filter unit with small pump/motor group. This unit is should contain a B1 or B3>1000 absolute rated filter. Unless the ingression rate is excessively high, this will resolve most contamination problems.

Another option is a high speed centrifuge. Centrifuges have exceptional high performance in sub-micronic ranges, but they require pressure between 30-80-psi to insure rotor speed. Secondly, they do not work in high viscous oils.

If you need a source on the off-line filters, please contact me.

Dear Mr Bert A. Hibl:
A filtration specialist is what I was looking for. I am setting up a facility for waste oil filtration in a staged basis or a series filtration with various vassels. Between vassels a filtration equipment of each time less micron rating will be used, like >100 um, then >75 um, then >60 um, then >45 um, then >20 um and so on. Is this feasible?

Thanks in advence

Jesus, please email me directly
gtrujillo@noria.com

Don't make the mistake to remove only the hard particles (e.g metal, sand,plastic, etc) but also the soft particles (e.g. varnisch and water). I advise not to talk with a filter company only. To use recycling oil you have to take into account also the viscosities and the additive pacckages of the different oils. If you don't know what are the effects for the your customers leave it. Contact me.