I've got the Mcmaster-Carr 5 micron trade size 8 bag filters that are supposed to flow 100gpm. I hose clamped one to my pump to filter the oil going into the processor and it took around 45 minutes to pump 20 gallons through the filter. My pump will fill a 55gal drum with oil in less than 10 mins. should i prescreen the oil and pump through 20 or 30 micron filter before i pump through 5 mic? I tried gravity flow through the 5 mic first and it took hours to get 5 gals through. Just trying to get suggestions on how to speed up the filtering.
Thanks
mike

 

I prefilter with a 50 micron bag filter than run it through a 1 micron bag. I like to filter the oil when it’s 90 F. I will flow better through filter bags.

 

I gravity feed through a 100 micron screen and then a 5 micron bag when the oil is cold in order to collect any chicken or fish fat. I then pull the filter bag out of the barrel and turn on the band heater and it heat to around 150 degrees for a day or so to settle out the water. I then drop the temp to about 125 and pump the oil through a much larger and supported bag filter hot. Next time I order filters, I'm going with a 1 or 3 micron filter for the last stage.

 

I've found that my main problem with filtering using the 5 mic bags is that the bags clog up with fat and grease. For the first few minutes they flow pretty good, but as soon as they get a layer of grease on them the flow decreases significantly. I've let the oil settle for quite a while to get most of the gunk to settle to the bottom, and it does but I'm still having a problem. Just trying to find out what the largest micron is that will filter out the grease so I can get a washable barrel strainer in that micron size. Strain most of the grease and fat out using the washable strainer and then run it through a 10 mic bag, then a 5 mic bag into the processor. Or will processing break down the grease and fat and settle it to the bottom as glycerin that can just be drained off instead of worrying about filtering it out? Just trying to speed up the filtering process so it doesn't take days to get 25 gal filtered into the processor. Thanks
Mike

 

The grease will change to Biodiesel when the glycerin falls out.
You only need to filter out the big chunks of stuff before making Biodiesel.

Save your fine filtering for the Biodiesel.

 

Thanks willbd, that's what I was hoping to hear, but wasn't sure. Just pre screening into the processor will save a lot of time versus trying to filter it like i've been trying to do. Now that I know that and i've got all the paint off the inside of my processor drum so that it doesn't ruin my next attempt, i'll probably put in another 25 gal batch tomorrow and give it another go. thanks for the help.
mike

 

blkbeast,

How do you remove all the water from your WVO?
You need to dry your oil before making Biodiesel out of it.

 

The one batch that I have put through that peeled the paint off the inside of my processor drum and turned into junk, I dried it by turning the heat on, let it sit for an hour getting up to temp (approx 150deg), and then turned my pump on and let it circulate for another hour at the same temp. I don't know if that is suffecient or if I should keep it up to temp and circulating longer with maybe a fan blowing on my pump discharge stream to speed evap. I remember reading somewhere on here about putting some of the oil into an old skillet or something and heating it to over 200deg to test for water content? If you get a bunch of sizzling and snapping it's got water? I guess I could do the skillet test before I start heating my processor, and then do it again after it's heated up and circulated for an hour to see if there's still water. That should tell me if what I'm doing is sufficient, or if I need to let it circ. longer and/or add a fan. I'm still trying to figure this all out, so I can use all the advice I can get.
Thanks

 

I did some more reading and realized what I was planning on doing to dry the oil is actually for drying the biodiesel itself. Now from what i've read I'll heat the oil up in the processor to over 140deg let it settle overnight and then drain the water off the bottom before I start the pump to begin making BD. I'm glad I decided to read up on it some more. I'm going to go get the heater turned on a 25gal batch now.
mike