Here's a filter housing I designed today. I'm going to try and prototype it this weekend:



I want to be able to cold filter my collected oils without having to constantly monitor and attend to the activity like I currently do. I'm thinking that I can gravity feed a couple of bag filters in housings on a manifold and, as long as I don't try to put more in the top tank than the bottom tank can hold, it should be a set and forget situation.

I've searched the net and come up with nothing when it comes to an inexpensive bag filter housing so, here's my idea for a home-grown filter housing. It's made from standard 6" PVC tubing pieces and some home machined goodies. The cover plate and retaining flange could be cut (with a sabersaw) from 3/4" thick nylon kitchen chopping board. It isn't shown in the drawing but, depending on the bag filter used, an adapter ring made from the same material would be cut to fit on the inside top edge of the 6" tubing with a hole in it for whatever size bag you were using. A homemade bag support that fit against the top edge of the 6" tubing would function the same way too.

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.

I've thought about that too and I'm just going to try it first without a bag support. There's a pressure differential across the filter media so the oil will have to flow despite the fact that the media is pressed against the wall of the housing.

If that doesn't appear to be working fast enough, it wouldn't be a big deal to make a bag support basket out of hardware cloth.

My goal is to be able to have the filtering process go unattended except for initally making sure that you have enough storage volume for the oil you intend to filter.

Good, sounds like you have that point covered.

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.

I don't have any problem with the bag just hanging in a bucket, but the flow control as the filtering slows is what I would like a control for. I considered a bilge pump switch and pump arrangement. So far I am not filtering enough oil for it to be a problem but I am like you in that I would like unattended filtering.

Right now, I'm using twill weave, denim sock filters without any support. There's no distortion. But, you are right about distortion causing a problem with conventional bags.

I thought about a float switch arrangement but decided a seal pressure filter would be easier and simpler to implement. I have to do something, the economy of WVO is qwuickly lost if it takes 3 hours of my time to process 35 gallons of oil.

I made an elcheapo housing from a restaurant feta cheese bucket (flat sides) and a bunch of pvc pipe. It was fine until the valve I placed at the base of the bucket clogged and then the whole thing just sat there oozing oil al over the place
V2 saw me cut an opening in my receiving barrel top to allow the filter bag to hang inside. The bag is supported by plastic mesh in the form of a large square bag. The bag is hose-clamped onto the outside of a piece of PVC pipe which is then adapted down to hose size.
I can gravity feed it from cubees or pump oil from a settling drum.
I'm not sure why the valve plugged, I just chalked it up to being one more messy lesson I can attribute to being to stubborn/cheap/stupid to buy Dana's filter plans. One day I hope to get it right or buy the plan's and get it right.

Good luck, Glenn

I have a 5 gal bucket that I pour my cold oil into and then hoist into the air and secure it. It slowly drains down - through a chaeck valve -through a tube into a unit similar to yours (made from pvc with a course screen that can be cleaned) with a bag (mage from denim jeans) attatched to the bottom of it. the bag hangs down into my 55 gal drum about 10 inches or so.

I dump in 5 gals of oil. hoist it up - via a pulley, secure it, and then leave. very easy self contained unit.

the only problems that I have run into lately is that becuase of the falling temps,I have to warm up the 55 gals of oil for several hours before I pump out - using a new gear pump that I just purchased from northern tool for $130, which works awesome with the warm oil, about 17 gals in about 5-10 minutes.

shawn

quote:

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Originally posted by Kyoto Dragon:
The bag is hose-clamped onto the outside of a piece of PVC pipe which is then adapted down to hose size.

Good luck, Glenn

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This is about what I am after. If I can bond a pipe to the bottom of a 5 gal bucket and clamp on the filter bag it will be a workable solution.

Gotta find out what kind of plastic a bucket is made of and how to make the connection.

I think you'll find the variety of plastics annoying. I would just try some ABS cement and a scrap of pipe to see if it will bond. Plastic welding is possible but bonding different plastics could be brutal.

Glenn

I work in the petro chem industry and we use bag type filters in many applications and run as much as 200 psi differential across the bag and steam them for decontamination with 350 deg steam and have no problems. Of course we use a bag support basket in all apps. We filter down to as fine as 1 micro at 100+ gpm using an 8"x36" bag for product spec with no problem. There are different types of bags for different apps. and they have temp and DP specs for each type depending on vicosity, temps and pressures of the liquid.

My 5gal buckets are HDPE high density polyethylene plastic. It can be welded but it is not the best for welding or glueing. Loctite makes a plastic cement that will glue it but it says it is not weather proof. I found a 1gal bucket made of the same material that fits the bag filter and will try to join them. I am not expecting much but will report my results.

Try a length of pvc pipe the same dia as your filter, that is long enough to hold 5 gal. One clamp and your done.
A 7 inch pipe holds 1.99 gal per ft.

Ken

quote:

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Originally posted by KenL:
Try a length of pvc pipe the same dia as your filter, that is long enough to hold 5 gal. One clamp and your done.
A 7 inch pipe holds 1.99 gal per ft.

Ken

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Thanks, A solution that is elegant in its simplicity. I thought about this and assumed it would take a longer piece of pipe. I actually took a filter bag in lowes and was test fitting it on pipes. It perfectly fits the expanded end of 6" PVC pipe.

I am still going to try to weld the plastic, I bought the welder (HF $29) a couple months ago and have been wanting to try it. If it works, the bucket implementation will be less cumbersome to operate.

This message has been edited. Last edited by: OilMotor617,

For what its worth.

When I was still experimenting with plastic buckets I tried welding them with a torch and (disposable) hot knife..with fairly good results. Not pretty but functional after a bit of practice. I eventually found that carefully cleaning the areas to be joined with a good solvent(like ether) and then using construction adhesive (like "liquid nails") worked even better. I usually tried to rough up the surfaces with sandpaper I wanted joined to give the adhesive a better grip. This combined with using the adhesive like a weld fillet rather than "glue" gave me fairly good results.

Update on my clamp it on the outside technique ...
the bag has a tendency to slide off when the system is pressurized. This was not an issue in warmer weather feeding from cubees, however, this weekend I was pumping (by hand) from a settling drum and the bags proved that they could not be clamped with enough force to retain them while pumping .
I think this could be remedied by adding three lugs on the face of the pipe to stop the clamp's slide. Even better would be an even flare but that would be tough to achieve.

Score this weekend :
Education 1
Spillage 0

Good luck, Glenn

I thought about the slippage and planned on tieing a zip tie under the filter to give it something on which to grip. May even have to pin the zip tie in place. I am not planning to pressurize my filter. May have to reconsider as the temps drop.

What if you took a piece of plastic like they make cutting boards out of. Cut an appropriate circle to fit inside pvc pipe. Drill hole in center of disk and tap it to screw onto through hull fitting. Take a wood router and router a lip to hold filter bag on the outer edge of disk. A thick enough piece of plastic and you could router a flat bottom u shape to fit a hose clamp to hold filter bag. With bag supported by mesh cage from below. I would think this should work. Just an idea.

This is cut and paste from a previous post.

Pre-filter.
Using a 5 gal plastic bucket. Cut a hole in the bottom ~2" from outer edge. From inside bucket insert pvc fitting.( One end has male threads, the other is female smooth. Grind female end down to base before inserting.) From outside bucket place O ring on threads and screw on a female threaded coupling. Apply a coating of pvc glue to outer edge of fitting that is inside of bucket to ensure seal.
You now have a 5 gal bucket with a bung in the bottom.
Get a yard of fabric (perhaps denim). Fold it in half (2 layers). Place this in bucket lapping outside top rim. Snug a large pipe clamp just below top rim and over fabric edge.
Sit bucket on 55 gal drum with bucket bung in drum bung. Pour your oil in the bucket.

This message has been edited. Last edited by: DN,

DN, that is very similar to what I was doing until I switched to denin for my filter material. There are seemingly infinite varieties of polyester felt available and the best I could find did a marginal job of filtering. Denim seemed an adequate filter. With tested and rated filter bags available for less than $3 each I think it is false economy to improvise filter media. I still use the felt for a prefilter. Experimenting was fun, BTDT.

This message has been edited. Last edited by: OilMotor617,

I have edited my previous post to remove the felt reference .