I use an unmonitored system that is a variation of several that I read about.

I use 1 micron nominal/3 micron absolute filter bags that have I metal reinforced band in the lip and a handle, a 5 gallon water cooler type bottle, three Home Depot 5 gallon paint buckets, 2 lids for said buckets, and a PVC pipe joint for a sewer line that is female on one end.

I cut a hole big enough for the male end of the PVC pipe in one of the lids. I cut a hole in the other lid that is large enough to go around the bottom of one of the bucket. I cut a hole in the bottom of one of the buckets, and I put the second lid onto the bottom of that bucket and the first lid on the top of that same bucket. I put the PVC pipe into the first lid, put a filter in the PVC pipe, and then put the second lid (etc.) onto to one of the remaining cans. I put the pre-filtered oil into the water bottle and carefully place it into the filter bag. When the oil fills the filter completely, the vacuum that is formed stops the flow out of the bottle until there is room in the filter. Viola, unmoitored filtration!

When it is finished, I move the filter assembly onto the other remaining bucket and pour the filtered oil into storage. Or onto the basement floor.

I filter my WVO with a painters airless strainer bag. You can find them at any major paint store. I bought a large cone strainer from a restaurant supply store and put the strainer bag over it. They have an elastic strap that holds it over the cone strainer. This works well with room temp oil except for creamy or hydrogenated oil which I avoid. That type of oil clogs the filter bag quickly.

240 volvo, I need a picture of your setup...

Hi

I am about to filter my first batch of oil. I'm havign trouble finding someone who can sell me bags locally - or even knows that they exist)...
I am wondering why not just use a simple hardware cloth structure of similar size to the bag and let it hang until empty. It would be easy to hold it in place and seal with silicone or other sealant that the WVO is OK with wouldn't it? I read a lot of complicated soundingand hard to follow despricption for contraptions and it seems I must be missing something pretty major here.


I'll let you know how it works out, but...What exactly is the major problem?
Thanks

quote:

Originally posted by earth drive:
Hi, all,

I am new to this, and have just started to make my own Bio, ....and fill it to say, 75 percent with medium grade wire wool. This wire wool can easilly be cleaned as required and re used. What do you think.

Hmmm if that is all you are using for a filter, I think one would need to be carefull about small metal particles in the oil........did it work?

I use a X-100 filter housing with a absolute 1M bag. I heat and then let the oil settle in insulated drums for at least a month, sometimes several, pump it into a clean drum, heat it and cycle it through the housing for about 7 hours. Very easy, very clean. 55 gal batches.

Well I tried it, but unless I am doing something wrong, it takes a lot of time for the filtering (not pressureized).
I am filtering my first batch of WVO now. I just cut a hole int he top of one 5 gal oil bucket and hole in the top of another big enough for the filter bag to go through. I built a round cage out of hardware cloth to hold the bag above the oil. A hole and tap in the bottom bucket provides an outlet for the clean oil into anouther bucket. Works great for the first three or four gallons, then slowed to a trickle. I have to keep filling the bag up further and further (filter is 7" dia x 32" long) and it filters down to where the previous level was and then slows down seriously. It is a 5 micron bag. The oil seems pretty well settled before going in.
How fast should it run through there? How much oil can one of these bags filter before it is completely clogged? Can they be cleaned out after?

Thanks

Fleamer

quote:

Originally posted by john galt:
[QUOTE]The oil seems pretty well settled before going in.

...and that seems pretty vague, since it obviously isn't settled enough.

If the oil isn't cold settled till clear then it will quickly clog filters.

Also WTF is this reference to some unspecified material called "WVO"?
"WVO" can be anything from hydrogenated sludge that looks like peanut butter to clear oil that looks almost new. QUOTE]

The oil has cold settled for about three weeks since it has been in my posession and it was failry "clear" when I got it. It is canola oil and very clean. Before I start to get any discolouration or cloudiness coming when pouring into the filter, I stop. The standard "pan water test" shows no water at all in the oil.
As this is my first experience with Waste Vegetable Oil I'm not sure what "clear" means. It certainly doesn't look like new oil you'd buy in the store, but it is an amber colour...the sludge is on the bottom. From the pictures I see where folks are making biodiesel, this oil compares pretty favourable in colour/clarity to the stuff they are using.

I'm not sure that the term "WVO" in this forum is a very unspecified material. Perhaps when you get to specifics of a special problem, but probably 99% of the reference to oil here uses the term "WVO". Perhaps we need to change that if it is an issue - before going to WTF.

All this talk about PLASTIC! Why not get hold of good old METAL buckets, solder an appropriate tin can to the bottom (complete with a lip to help a slipping filter bag) and stop worrying about plastic welds and glue......
QTBAND

quote:

Originally posted by john galt:
What does the material that clogs the filters look like?

Once the oil has cold settled to drop the hydrogenated oil and animal fats, then heating it or diluting it with diesel fuel will help speed up filtering.

Thanks John

the fileter just gets dark. I haven't taken it out and studied it yet, but will do so this week sometime.
I am now using biodiesel in the car so may try diluting a bit with that. Could you turn the filter inside out and run a bit of biodiesel through it to clean it - instead of diesel? If that doesn't work I will try heating it.

Thanks again for your suggestions.

Cheers


Fleamer

I would recommend you clean the bags inside out with water after you filter. Let it dry out and it should work like new. I would also recommend step filteration 150 micron (T shirt style) to 50 micron to 10 micron.

Or you can do what I do and pump the oil through this baby (picture attached)
50 micron filter page on top and 10 micron cartridge on the bottom. About $400.

quote:

Originally posted by Fleamer:

quote:

Originally posted by john galt:
What does the material that clogs the filters look like?

Once the oil has cold settled to drop the hydrogenated oil and animal fats, then heating it or diluting it with diesel fuel will help speed up filtering.

Thanks John

the fileter just gets dark. I haven't taken it out and studied it yet, but will do so this week sometime.
I am now using biodiesel in the car so may try diluting a bit with that. Could you turn the filter inside out and run a bit of biodiesel through it to clean it - instead of diesel? If that doesn't work I will try heating it.

Thanks again for your suggestions.

Cheers


Fleamer

IMG_0006.JPG (1,359 Kb, 145 downloads) Two Stage Filter housing

quote:

Originally posted by OilMotor617:
I haven't figured this one out either. I have seen designs like yours and considered them but the shortcoming that I see is that the sides of the bag would be pressed up against the side of the housing and may impede the flow through most of the filter. I saw filters like this used in chemical plants but never paid attention to the details.

Although, If you used a PVC pipe with a larger diameter then you wouldn't have the filter pushed up against the walls... this would only really work for gravity filtering, a pump system would simply pass around the bag and not filter at all.

Hi I know your pain, im currently working on a 3 stage forget it system, with a pressure activated 12v pump, basically im having a set of housings made for me this time if they work and are cheap enough ill post them. i have been experimenting with the standard size one bags, under pressure which means you get way more use from them. spec suggests that 30PSI is max for these bags, but its running at 15PSI at which point the pump turns off then back on again when pressure drops. The trick it seems is getting the housings just right, after a few failures using old gas bottles with welded front motorcycle brake discs(centres removed)on top bag in middle and car brake dis on top with tank fittings, i discovered air is the killer. basically i want housing 1 x 25micron to haousing 2 x 10 micron then straight into tank with a ball cock operated reed switch to turn the whole thing off.

anyway its getting there and if i get it working ill post details. all being done on the tightest of budget

quote:

One other point is more operational than design and concerns the bag itself. I have read that the bag can distort under pressure and stretch to the point that it does not filter to specification.

Note on the above, I blew two bags today they both went in the same place along the seams, plan B is the bag inside metal cage and pressure switch to prevent this.

PS look at the working pressures of car fuel pumps, i got one with a flow rate of 2.5l p/m at 60 psi. too much obviously but easy to rig up to a cheap oil pressure gauge and reed switch to turn pump of at the pre ordained point.

I made up a fitting for a pressurized bag out of a 150mm Pvc pipe end cap, a couple of backing nuts and a short length of plastic all thread.
The cap simply sits inside the bag and is held in place with a large hose clamp.



I roughed up the sides of the fitting on the wire wheel if my bench grinder to stop the bag slipping off which was initially a problem.



I checked on the specs for the bag and they are good to 10 PSI unsupported without loosing any filtration efficiency.



I use the setup in my drying tank so the oil is dryed and filtered at the same time, after running this setup for a few batches of oil I notice my onboard filters are lasting MUCH longer and I was surprised at the amount of rubbish I got out of what appeared to be very clean pre-settled oil.

This setup could be used with a pump as I have it or it could be used with a gravity system.
I have found the only time the bag will blow off is when it is full and the pressure exceeds what should be put through it. I am looking for a suitable gauge to put on the top of the PVC end cap to monitor this.

I am going to put a ducted lid on my dryer to stop the annoying splashes I get from it and will simply push the threaded fitting through a hole in the lid and support it with whatever fitting screwed down tight on the other side.

At the moment the thing just hangs quite happily inside my oil processor and with a fan blowing from the top, I believe the surface area of the bag itself also helps expose the oil to the air and dry it.

Good idea; I stick a bag in a barrel bung and then run it through the final stage. One suggestion would be to turn the bag inside out as the way it would filter normally. I've noticed the bags are seemingly less permeable from the inside out, probably just due to the weave of the fabric leaving it smooth on the outside.