HEAVY DUTY GEAR BOX OIL FOR CEMENT MILLS

Unless the oil you use has a solid lubricant additive such as Moly Disulfide or the Chevron Borate you can filter down to 1 micron without any problems.
bruce

Sorry to disagree with Bruce 381 but I have had specific experience with heavy viscosity gear lubricants and it is not just about the solid additives mentioned. Pretty much most gear lubricants have additives contained which will filter out at <10 micron. Pall filters have done a lot of specific testing and I was involved in setting up filtration for a large oil companies blend plant. The type of filtration used also has a large bearing on what is pulled out of the lubricant.

When it comes to dragline gearcases I suggest the metal wear will block most fine filtration systems before you get to <25micron.

I suggest you talk with your lubricant supplier and request minimum filtration sizes from them then talk with a filtration expert.

Hi

Normally modern gear oils can be filtered down to 1 micron filtration without additive drop out. I surgest you call your suplier and have his advice
Per

I fully agree here:

quote:

When it comes to dragline gearcases I suggest the metal wear will block most fine filtration systems before you get to <25micron.

I Disagree here:

[quote]Pretty much most gear lubricants have additives contained which will filter out at <10 micron.[quote]

This has NOT been my experience this statement does not take into account the bread range of additives used in gear oils.

Now as far as a blending plant enviroment a lot "gunk" can get into the oil blend and is why most plants will filter finished product, this gunk is normaly not "additive" per se but other debris that get into the lube blending line from about evrywhere from tank, truck, rail, pipeing, hoses, bags, etc.

bruce

I would have to agree with Bruce on this one. You shouldn't have any problem filtering down to 1 micron. Even the Moly Disulfide used in our gear oils is under 1 micron in size.

Have to agree with Rodney on this one, the practicalities of filtering high viscosity oils is of importance, compare ISO 32 hyd oil and ISO 680 or 1000 oils typical for this application.
Normal gear oil additives are soluble with FZG 12 pass at ~ 300ppm phosphorus EP additive but i doubt anyone has ever tried to filter a heavy gear oil to even 5 microns and then the wear and contamination on such sites, filter consumption would be v large.

I'm not dis agreeing with everything here.

But any good major additive supplied gear lube additive for industrial use NOT friction modified gear oils will be OK to filter to 1 micron with out additive drag out.

Now the practicality of it is that Other than low vis 150 cSt or so it maybe a problem to get flow rates due to high vis that is not my bag.

But he asked can he centrifuge it and yes that would be best NOT filtering.

Also
""I suggest you talk with your lubricant supplier and request minimum filtration sizes from them""

I'm a Mfg and that is what I would say the cleaner the better.

To use a centrifuge.

Use back up lab testing upstream and down stream of centrifuge to valid the setup.

I have gear oil additives in low vis oils 46-68 on loop filtration @ 1 micron filtration for years and NO problems.

1500 vis oils are a problem due to vis but additives will stay in at least what I do.
bruce

(I HAVE FEW QUESTION ON USING HIGH VISCOSITY OIL RANGING FROM 150 CST -1500 CST FOR HEAVY DUTY GEAR BOXES FOR CEMENT MILLS AND DRAG LINE GEAR BOX OIL.

I HEAR PEOPLE SAYING THAT THE FILTERS ( BARRIER-CLEANABLE/REPLACEABLE) MUST OF ABOVE 10 MICRON SIZE ONLY AS LESS THAN THIS SIZE WILL FILTER THE ADDITIVES ALSO...

BUT AS FAR I KNOW THAT THE ADDITIVES ARE SOLUBLES AND CANNOT BE SPERATED OR FILTERED.

PLEASE CONFIRM AS I WANT TO INTRODUCE HIGH EFFICIENCY CENTRIFUGES WHICH CAN SEPERATE PARTICLES DOWN TO 1 MICRON

PLEASE HIGHLIGHT ON THIS ISSUE)



This is an interesting topic and lets make sure info here is correct.

This is simple, The lubrication film thickness formed is 1 µm or less in large industrial gearboxes therefore if you want to make a difference you must filter down to the oil film thickness, 1 micron or less,
Experience has shown it's far less expensive to keep dirt out than filter out so breathers vent contamination must also be controlled @ < 1 µm with cellulose media proven to be best,
(Expansion rate of air is 10% per every 10°C change in temperature}

EP Gear Lubricants use chemical boundary additive packages that are dissolved into the lubricant and cannot be filtered out.

The concern with extremely good filtration on large drives is that it makes monitoring rate of wear very difficult as when abnormal wear occurs all the wear debris is in the filter.
When running large drives we would be more comfortable with controlling breather ingress down to 0.2 µm, filtering new oil in @ ISO 4407 16/13 and run the drive on particle count and maintain the lubricant at an ISO 17/14 cleanness or better,
when particle exceeds an ISO 17/14 check by microscope what the contaminant is and then if required filter @ 1 µm to remove,

Regards


Rob S

I think as a start, talk to your oil supplier to see what is actually in the gear oil - do they contain any lubricating solids such as molybdenum disulfide or any other solid material. Find out at what micron size these lubricating solids are at - as there are fine solids and coarse solids. Also if the oil supplier has had any experience when such oils are filtered and under what filtration conditions. This hopefully will allow you to decide which path you need to take.