Thread: Coalescer, how big a difference?

A little while back a few members set up some coalescers on their machines, like the zebra model, just wondering how its doing by now?

I'm in the process of getting the coolant out of my vmc finally after about a year and half of it being in there, stayed decent overall but lots of plastic and small chips got in there and the current skimmer on the 2412 only skims the last compartment of the tank, so I plan to cut some of the ribs out so the floating oil can move end to end and be skimmed out
I get the feeling with my mods and filter I'll be adding I should get 2-3yrs out of it now (maybe more)with much less crap getting into it.

So anyway, just debating putting the 500-600$ in one of them coalescers on top of that, so how much life has it added to your coolant?

I'm interested in the answer too.

A related potential hijack: is it possible to use one of these coalesces, or something like it, as a pool vacuum? By that I mean something with a strong vacuuming action and a pickup tube I can run around the bottom of the tank and in the corners etc., to pick up all the fines settling there, filter it, and return the coolant to the tank? The coalescer seems like it only gets the stuff floating on top, the junk that sinks to the bottom is there until you do a complete change and muck out the tank. Does anyone make something like that?

We use the Keller ones on all of our machines...they use a floating pick up that is a bit cheesy, but works well enough. Well, on one machine we us a non-floating pick up - the hole in the tank is too small to get the floater in there and we didn't want to cut a bigger hole because of where it is in relation the the chip conveyor and falling chips. The units do work really well as far as removing floating oils and such, even aluminum fines that seem to gather to the floating oil and in supension. They use a disposable water filter that you can get at Home depot or McMaster Carr for a few bucks - depending on how much we are cutting, we may change it daily to help keep the coolant fresh. As far as coolant life goes, keeping the concentration correct with a refractometer is good insurance to keeping the sump is good shape, along with removing the contaminants. We have not had a sump in service more than about 1.5 years while using these, but believe that they should extend the life quite a bit...we did have some "bad" coolant, there was a bad component in the oil, so the coolant manufacturer rep and the local distributor came out and cleaned and replaced the affected sumps. ps...I think the cheapest Keller unit is pushing $1k, but we felt they were worth it in the long run, no oil mess from the skimmer bucket overflowing, not shop vacuuming the oil on Mondays, never dealing with a rotten egg sump...the list goes on. Maintenance is minimal, and although we will have to rebuild the air pumps someday, they are still chugging away after a couple years, and rebuilds are quick and easy anyway.

Swarf, the air pumps on these units do have quite a decent flow when turned up (but will use a TON of air too), so using it to clean the sump corners would probably work fine as long as you were mindful of the filter plugging, but since the pump really cannot be harmed by low flow like a centrifugal pump, it's really no big deal. You will still have to remove the covers from the tank to get to the nooks and crannies, but it would save you from draining the entire sump, and you could get a substantial amount of the settled crap out of the sump.

Steve

Originally Posted by swarf_rat

I'm interested in the answer too.

A related potential hijack: is it possible to use one of these coalesces, or something like it, as a pool vacuum? By that I mean something with a strong vacuuming action and a pickup tube I can run around the bottom of the tank and in the corners etc., to pick up all the fines settling there, filter it, and return the coolant to the tank? The coalescer seems like it only gets the stuff floating on top, the junk that sinks to the bottom is there until you do a complete change and muck out the tank. Does anyone make something like that?

What you want is a sump vac.

Cecor makes a nice one, couple of good vids there.

Cecor - The Sump Sharkis CECOR's smallest sumpcleaner used for cleaning dirty sumps of machine tools.

I've got the eriez sump vac toward the bottom of the page. The orange boxey one. It works great!

Sump Cleaners - Products || Eriez Headquarters

Exair has a "budget" model

EXAIR Chip Trapper: Vacuums in the liquid with solids, pumps out only the liquid!

I've actually used my keller to suck the sump all but dry (moving coolant into tanks for a building move) and then to fill the sump from a tank. To get at the, er, stuff, that is on the bottom, I use a really cheap shop-vac reserved for this purpose, which believe it or not seems to work fine after a couple of years.

It coccurs to me that swarf_rat means something more like "take the keller hose, but it in a heavy donut that holds it near the *bottom* of the tank" and feed the filter that way. I suppose that would work, but not be as effective as removing the stuff that floats on top. But I've not tried it.

Edster's links are right on target for what I was thinking about. But the "economy" Exair model is right at $1400 ! Also the only one that states the air usage is Cecor, at 80 cfm. So I would have to add the price of a 30hp screw compressor and new service drop to run it.....

I'm not talking about something running continuously, rather something to vacuum up the crap every couple of weeks.

I have found that a cheap $hit Home Depot bucket head vacuum can almost do this at $18. But it fills up the Homer bucket in about 15 seconds, blows coolant out the exhaust, and generally makes me question its safety in this use.

The cecor is 53 - 80 cfm, but it will fill it's 60 gal tank quickly so it's not really going to need that continuously. But that was the reason I went with the electric (110v) eriez sump vac. I have about 50-60 cfm of compressed air availiable but didn't want someone cleaning a coolant tank to cause the cnc's to shut down due to low pressure.

I also have a royal pneu vac. It's the same basic prinicple as the exair unit but it doesn't pump out fluid. It does a good job and doesn't use much air. I've used it with my old 3hp champion and it was fine. I doubt you would have a problem running the exair chip trapper either.

http://www.royalprod.com/product.cfm?catID=13

http://www.royalprod.com/img/categor...euVac_Pump.pdf

Originally Posted by swarf_rat

the "economy" Exair model is right at $1400. Also the only one that states the air usage is Cecor, at 80 cfm.

Yeah, I could see myself buying an Exair (for the convenience) but not a compressor beefy enough to run one (for the space/cost/noise). We only use air occasionally, and a portable 8CFM Quincy is sufficient. Going to 10x that capacity to run a convenience occasionally isn't practical.

Now that Royal products version is spec'ed at 6.3 CFM. That I can do. And the kit is less than half the cost.

The exair probably uses about the same cfm as the royal uses. Only difference is the royal won't pump the coolant back out of the drum, and no filter. I've had the royal for years, but only use it to pump old coolant into the waste drum. The exair is a better choice, it's nice to be able to vacuum up coolant and swarf, then pump the filtered coolant back into the machine or into another machine. If one of my machines is going to sit for a while I'll transfer it's coolant into a running machine. That way it's coolant isn't going bad an I don't have as much raw coolant use.

I got a mid-sized Keller last year and it works fairly well with a few caveats. If you cut a lot of fine aluminum it will stop up the filter faster than you think it will. You have to keep your coolant level pretty high in the sump for the floater pickup to work right - if it sounds funny check your coolant level. Floating oil still gets trapped in all of the high/low baffles that are in the VMC tanks - to really get them clean you have to pull all of the covers off and let it skim the individual compartments. When moving it between machines it takes two people and a five gallon bucket for the hoses and still always gets coolant on the floor. Even though it is a bit of a PITA to use, it does work better than anything else that I have found and we will probably add a second one so we don't have to more the first one around so much.

I found the Exair spec - 19 CFM. A lot, but a lot less than the Cecor. Probably can do that with my little 5 HP screw compressor. And, I just found a used Exair pump on eBay for $100 . Adding up the rest of the parts, looks like I can build one for around $400.

Question: I can put it on a 30 gallon barrel (more compact and portable) or a 55 gallon barrel (holds more, but still not a whole coolant tank full). Any overwhelming reason to do one or the other?

For reasons echoed by others above, I think this is going to be a better way than a coalescer. I have multiple tanks (on one machine), no room for the float in the convertor, etc.

Nice find! You will love having a sump vac.

I have my royal pneuvac on a 55 gallon drum with a dolly and I like it. It's not too ackward to manuver around.

How many machines with coolant sumps do you have?

My experience with coalescers is similar to that of making your own beer.....just not worth the effort. Regular surface vacumming of tramp oils seems much more economical.

Originally Posted by Edster

How many machines with coolant sumps do you have?

Only one. But it has four tanks, four pumps, and about 220 gallons capacity: conveyor holds about 30, tank about 50, TSC tank about 120, and spindle cooler about 20. First three spill over into each other in different ways. The TSC and spindle cooler currently dry. With a 55 gallon, I might be able dry out either the conveyor or the normal coolant tank which might be convenient at times to clean, service filters or pumps, etc.

Now I am wondering if there is a way to trap the tramp oil in the vacuum. I found the filter bags and holder (McMaster) which would catch the chips. It would be nice to have some means to trap some of the tramp oil as well. I don't get a lot - its a roller way machine with a lube pulse only every 30 minutes. I am thinking I would vacuum the tanks top and bottom ever so often, then dump the coolant back in immediately. That would get the chips and fines the conveyor and filters didn't, and would be an opportunity to get the floating tramp as well - or maybe the vacuum will just disperse it again?