A filter for water?
 

I'll be going over options to filter out small elements out of a cooling loop, because:

1-The Cascade block design can really use it

2-If I go with the CPU backside cooling option, I'll need to filter out some finer elements too.

So while I Google, I'll let ya'll share your thoughts on it ;)


Update/progress:

-USPlastics is out: too expensive.
-The Surplus center is out: most filters are for air or fuel.

What size filter element am I looking for?

-McMaster has some reasonably priced unit. Gotta stay away from the "taste and odor" filter, as that's probably a charcoal filter. Specs are hard to find.
-Lowes is useless
-Home Depot is useless

My first thought would be a gold coffee filter, very fine yet water flows right through it. You'd have to cut it up and somehow get it in the tubing. But then there is the mixed metals concern. I am not sure exactly what metal it uses, it could be gold plated? They cost like $14 or so but if it was an option, you could make 25 filters out of 1 unit.

That's not a bad idea. I could drop it into my airtrap, so it'd be easily removeable, for cleaning... Make a cone, put a flange on it...

Ok, does anyone else have a better idea?

edit: link to airtrap:
http://forums.procooling.com/vbb/sho...&threadid=5613

We just need to find out EXACTLY what metal they are made of. If it IS gold plate, how bad would that be to mix with copper?

http://www.engineersedge.com/galvanic_capatability.htm

Maybe, maybe not.

http://www.thelenchannel.com/1galv.html

Gold and copper are pretty far from each other. That would be bad.

but as the first link points out, there must be an electrical return. This might explain a few things: a copper block with an anodized Alu top may easily have an electrical connection, through a bolt, where an Alu rad, and a copper block are hopefully not grounded together to the case... Hum...

Oh oh lookie what i found! Fine copper mesh! A 3" x 3" sample is $8... or is that for 100 of them? Confused on the ordering.

You probably want the finest one the 0.0045 diameter.
http://www.twpinc.com/twp/jsp/produc...pe=3&page=data

Darn nice find!

The finest mesh has 5.5 thousandth of an inch openings.

I need a ruler: never mind that, I need a microscope!

From the CPU backside thread, this is the smallest opening that I'll be dealing with:
.0226" (0.57 mm)

That's ~570 microns, so if I go with a filter element that'll catch anything that's a quarter of that size, I should be ok.

So I'm down to ~150 microns :D The finest element on that page would be perfect.

The next question is: how restrictive is it? I'll order it and find out. A 3" by 3" should be enough to make a cone.


Edit: measurement correction. 1mm = 1000 microns.
Edit: manufacturer measurement fixed.

If you use a paper filter or something similar, it most probably will blow up, as it will provide too much resistance to the flow of water, IMO.

Best to use filtering wool like material used in aquarium filters, it has relatively large open cells but the fibers provide great fine filtering without restricting water flow too much.

I personally use for my aquariums the type that is blue on one side and white the other side, it comes in large pieces you can cut to fit any opening.

Hey Ben,

You're into my present career area now. I have not bothered with your other thread, but am curious how you got to 570 microns. Is this some sort of minimum passage (awfully small for that) or something else? Quick summary would help as I'm too lazy to go looking through another thread. Where are the particles generated? Are they steadily being generated or do you need to do a one-time cleaning?

Anyway, you've got two very broad categories. There are absolute filters and nominal filters. Microscreens are an absolute filter as no particle larger than the pore size may pass. Larger particles may break up and pass, however. Nominal filters have no defined pore size but do get a size rating. Most paper elements are of this type. They'll remove most particles above the rating and many below the rating but allow progressively more to escape as size drops.

As a general rule, screens are pretty bad if you have a steady load of particles to remove. They offer no depth, hence can't really "store" solids. Head loss builds rapidly as solids accumulate. Paper elements and cloth elements each have a defined depth of filtration and offer higher solids storage between cleanings. Head loss does not develop as rapidly for a given solids load.

In each case, the accumulation of solids assists in the removal of new solids. The solids that build up form an additional barrier. The down side is what I've already mentioned: increased head loss.

The filters we manufacture are for water treatment. We use cloth media and design for a velocity through the media of ~15 m/hr. This limit is more due to using gravity feed and dealing with solids on the order of 10-50 mg/l. The media itself can handle pretty much any flux rate, but higher fluxes blow apart larger solids. The media carries a nominal rating of 10 micron and has a "clean cloth" loss on par of 1" H2O for every 10 gpm/ft^2. If you want a true flow of ~5 gpm and could tolerate losing six inches of head, you'd need 1/10 ft^2 or about a 4+" diameter cloth.

No, I haven't got anything that would suit your need. I work in the scale of MGDs, millions gallons/day. Although I do have a little lab-scale unit that cost ~$6K to build. It even uses one of those Little Giant pumps you're so fond of. . .

Either way you need a method of cleaning the filter. "Backwashing" or "backflushing" is most common and as the word suggests it involves reversing flow through the element. We control this automatically with a PLC, wash pump, valves, etc. Depending on how often you need to clean, you could incorporate this pretty easily into a system.

Thanks Dave, It's nice to hear from you again!

The dimension stated (.0226" (0.57 mm)), is the ID of the tubing that is used in the CPU backside cooler. It's a set of very small tubes that run under the CPU. There's a plastic tube that runs between the pins, and a copper tube that's thermally epoxied to the backside.

I figure that filtering for 1/4 of that dimension should keep those tubes clear, so I go from 0.57mm (aka 570 microns) down to ~150 microns.

N8 mentionned that these (CPU backside cooler) tubes would probably clog over time, from various deposits. Personally, knowing that my loop would be closed, I don't expect any new particles to appear. However... I can't say for sure if the coolant flow would eventually start flaking things off, or if any corrosion (copper,brass and solder only) would add any particulates. In other words, no, I don't expect a steady load of particles.

Also, if there are any deposits, I would expect them to appear in the "tanks" to the CPU backside cooler: a 1/2" PVC extension (aka manifold). That's a project that I'm still not sure I want to go ahead and execute, so the filtering is otherwise for the "Cascade" style block, which uses an array of small openings (~1mm ?).

So off hand, I'm more interested in one time filtering: i.e. filter the water, then remove the filter to let it run. If I don't go with the backside cooler, I'd consider leaving a 250 micron mesh filter in, but I don't see the purpose: all I'm putting in the coolant, is distilled water (a new gallon), and a corrosion inhibitor (Silkolene ProCCA, which is 50% mineral oil, mixed at 1%). I might add windshield wiper fluid, when I get close to building the #Rotor chiller.

I like the backwash idea, and I'd implement it, if I had room for it! I'll have to backwash it externally, that's all.:shrug:

Thanks again Dave! BTW, is there such a thing as a filter element that's in the form of a sheet, and rolled slowly, so it's continously "fresh"? Just curious. ;)

Ben,

For what you describe you ought to have a filter piped in parallel with a bypass. After filling the system and rarely thereafter you would open the filter line and close the bypass. After running through the filter line a while, you would switch back. This also allows you to change out the filter element while the system is running.

In this case a fine mesh would be all right. You can get microscreens in both metal and plastic and our competitors have them in the 10 micron range. The cloth we use would also be fine, but is not as amenable to locating in a closed loop as you wish. Unfortunately, I'm not sure where to direct you to obtain wire or plastic mesh that fine.

Best luck.

Now someones employer must live right to afford a mere $6k for a small water filter, No offense now. :D But this also is in My area of Expertise as I have had a 100 Gallon Aquarium in the past and I have used a Vortex Diatom Filter with It and It's the Best in the Business as far as I know, That and It has It's own pump and a quick disconnect option, So that the filter can be changed when needed without loosing any water. It can be placed on the floor or inside a Desk, They have 7 models, One does 460 Gallons per hour,,,,, Hopefully I've been able to help.:cool:

Thanks again Dave!


I was thinking about simply dropping the filter in and out, since my airtrap is U shaped, with a lid that sticks out the top of the case. I don't think I'd have room to fit a bypass, but I sure wish I had thought of it, before I put it together: I might have tried to squeeze that bypass in there, somehow!

zoom314: thanks for the tip. The Vortex unit looks nice, but I was simply looking for a filter, not an entire pump and filter combo. It's also outside my budget, and of course, I don't need the active charcoal portion, since I won't be filtering for microbial/odor/taste ;)

I'm still going to go ahead with the 5 micron sample sheet. I'll make a cone shape with it, and add a ring so that it stays on top of the airtrap, capturing all the flow. I can then add a pull out pin/wire, so that I can remove it, simply by uncrewing the cap that will be sticking out the top of my case.

If I drop the backside cooler, I can rebuild the filter with 150 micron mesh, and just leave it in there, if it's not too restrictive.

bb2k, interesting project...

I think someone has mentioned it earlier, but I would think with today's athlons xp, cooling the cpu backside would result in very minimal. and keeping those tubes cleared...

I found this thermal image of the backside an epox 8rda+ mobo interesting. See how much heat the mosfets are creating and how that is effecting the heat near/behind the cpu. If you can reduce the heat produced by those mosfets, I would think you would have a greater impact on cpu temps.

http://homepage.ntlworld.com/bubo/Ba...ar_thermal.jpg

Source: 8rda.com

I have 3 modified heatsinks (cut in half length wise really, not available anymore without buying one of those Thermaltake Heatspreader kits, Mine looks just like those blue ones they sell with the Heatspreaders) on the mosfets and a fan aimed at them, But My cpus Volcano 9 is the real limiting factor right now, Like 104F right now (Its been as high as 114F though at around 190Mhz fsb, I couldn't go higher then).:cry: Those Blue heatsinks are attached with ASTE, They'll never come off. :evilaugh: The Ram will stand up to 3.04vdc though, Even If the motherboard in stock trim won't go beyond 2.9vdc.:rolleyes:

Not to worry, I'll be looking into a MOSFET block ;)

Then you can come by my place, I'll break out a roll of IR film, and we'll compare notes ;)

I have been trying to dream up a water cooled mosfet/voltage regulator block for a while. My 8K7A boards all had aluminum heat sinks on them and they got damn hot. I put a 60mm fan over them once and was able to get a better overclock at high Vcores. I think keeping them cool will help stabilize the power. I will have to look into again on my Abit KD7.

I'm using a fine micromesh plastic washable filter in my open system, and it make a very good job keeping my block clean. I tried several types of filters and this was the least noticeable in pressure drop. When it's dirty, waterflow can suffer, but even with the wide exposed water surface I have, mainteinance is required once a month. Filter cost was about $5 in a normal hardware store.

:D bb2k that I would like see... waterblocks for mobo mosfets... back to the topic, I still wonder how quickly those microtubes or filter are going to clog. anyways, can't wait to see you implement this uh experiment...

jaydee116- so true, when I first got my 8rda+, I slapped on some alu ramsinks w/o a fan. at 210+fsb, I dared not touch em for fear of 3rd degree burns! As my cpu and NB are watercooled, they were getting very little air flow. Since then, added a 50mm fan above it, and surprising did see a slight drop in cpu temps (as read by the in socket thermistor)...

Well the way I've done My Mosfets, Which are all in a straight line I might add, It wouldn't be too hard, Sure I can't remove the heatsinks seeing they are ASTEd in place rather permanently, All I would have to do is clip off all but the outer 2 rows of fins (1 row per side really) and ASTE a Copper pipe of the right size in place and there I go, Instant Water Cooled Mosfets. :evilaugh: The only problem I would then forsee is the next owner (if any) of the motherboard would have to cool the mosfets with water, unless that person could figure out how to air cool them again. :) Me I wouldn't even try that of course, As It would be too modified by then.:evilaugh: :rolleyes: :evilaugh: And that would be someone elses problem by then. :evilaugh: The heatsinks I have attached to My Mosfet look like the ones in the attached image, even down to the color.:D

The only problem with watercooling your ram, is that the water temp might exceed the normal RAM stick's temp!:eek: ;)

I was talking about Mosfets, not ram.... I used the image I left as an example, Like this one too.:evilaugh: :evilaugh: :evilaugh: :evilaugh: :evilaugh:

bb2k, sorry for inadvertently hijacking this thread into mosfet/ram cooling...

anyways folks, back to bigben2k's original topic of micro filters...

Now even though It's an FIC AU-11, It is Identical to My Epox 8RDA+, Except for No LED output of course, Look at where the Mosfets are or at least should be (Hint: look for a Blue T).:evilaugh: that's what I did to the Mosfets. :evilaugh: Me too BB2k, No more here either.:(
The Mosfets on these motherboards are all on one side, This side.:p ASTE is Arctic Silver Thermal Epoxy for those that don't know what I mean, Otherwise I use AS2 for other things until I need more AS2, then I'll get some AS3 or ASC.

What sucks is when you got mosfets on the back of your mobo....:mad: