filtering/dewatering WVO

Fez_uk · 22-08-2013, 10:38

Who was the one here who set up a few drums to do this? Search function hates small words like bio wvo etc so finding it hard to find the thread.

Got myself a shed, And some supply of WVO I want to filter and dewater (free electric

)

arcascomp · 22-08-2013, 11:24

In the middle of tidying up my system to make life easier.

Currently I have one 205L drum with the top cut off (couldn't get a supply of clip tops that make this easy!) and a 22mm tank connector fitted near the bottom. The second drum has a standard immersion heater boss soldered in near the bottom, a 22mm fitting on the bottom, dropping through a central heating pump and being pumped up into the top via a pipe with a bunch of holes in.

A bit of plumbing and a bunch of full bore 22mm valves to isolate/direct flow and finally a couple of sock filters hanging over a final resting drum gets me to clean and burnable oil. Not the best setup, but works for now.

Basic approach: suspend an old bed sheet over the first drum (I support mine with a chicken wire 'baskets' to stop the edges of the sheet ripping), pour the waste oil through this. Best if you have the space to keep the oil settling for as long as possible to get the real manky stuff to drop to the bottom first and only pour off the better stuff. The bed sheet will filter out loads of stuff and also eventually clog up with semi solid fat custard. That stuff can be scrapped off with a ladle a few times before the sheet needs replacing.

When there's a reasonable amount in the first drum, open up a valve to pump this stuff up into the second drum. When full (or at least fully covering the element with oil - watch this cos a bare element gets hot and can cause big bangs!) turn on the immersion heater and start pumping the oil from bottom to spray in the air into the top, oil only needs to get to 50-60 degrees and the water will evaporate while it's being sprayed in the air. The drum being topless and having fresh air blown over i by a normal fan will speed this. You being topless will only save on the washing machine usage as you gradually cover everything in waste oil!

After a few hours pumping round you should be in possession of cleanish dry oil. Test a bit of oil in a hot frying pan, any water will sizzle or create bubbles as the oil gets hot, dry oil just sits there and eventually smokes. Wet oil will destroy your fuel pump/injectors so get this right.

Once oil is dry, you need to filter it to 1 micron to stop blocking the vehicle filters. Only ever filter at ambient temps because hot oil will pass through and then form solids when it cools. I slowly pump from my heating drum into a set of sock filters suspended over a 30L mango chutney drum and let gravity do it's thing. This then empties into a 60L barrel I take to the car and fill the tank with.

In cooler months, you need to thin the oil with either diesel or petrol. Petrol does this much better so you need less and petrol also strips out any residual water or other tiny floaty bits, so best to mix outside the tank a few days before pouring in.

arcascomp · 22-08-2013, 11:34

Phew! that was a bit of an epic!

I am planning to clean up the system I have to lessen the steps and tidy the shed slightly, basing the system round an upturned hot water cylinder as it has a nice curved bottom (fnarr, fnarr) although for processing a decent quantity, weld a cone to the bottom of a 205L drum as the resulting plumbing can be easier.

My plan is to still sheet filter and pump round in circles through a spray bar, but to then pump up into a vented (out of the shed) upside down hot water cylinder where using a venturi I will add the petrol from between 10 and 20%. I will let the oil cool a fair bit before this as hot petrol in a big tank does sound a bit dodgy! Once the oil and petrol are mixed up, turn it all off and leave it for a few days. Then drain the first few litres off which should be any settled sh1t3 and then filter the rest slowly as before. Oil with petrol added runs through the filters SOOO much quicker.

For a spray bar, fit a bent spoon on the end of the outlet pipe in such a way that the flow of incoming oil to the tank hits the back of the spoon and fans out, cheapest solution probably to get good oil to air surface area.

To maximise the life of any filters create a sock by stapling j-clothes together and put them in place to be the first filter - when they block up, remove and create a new one - much cheaper that way.

Fez_uk · 22-08-2013, 11:57

That's pretty much what I thought. Think my biggest cost will be a pump to transfer from drum to drum (and vehicle) and maybe another pump to circulate while dewatering and a heater.

How come you don't do all the filtering on the first drum?

Any advice on a cheap mains pump to circulate the oil when dewatering?

arcascomp · 22-08-2013, 12:04

If you're just moving veg oil and not bio, any old central heating pump will manage, but remember they need to be at the lowest point as they aren't self priming.

With a bit of careful plumbing, the same pump will do everything, if the shed is too far from the car (as is my case) you need something else to get the fuel into the tank, I currently lug a 60L drum out to the street and then use a £10 drill pump off Amazon to transfer it. Must buy a cheapo sack barrow to save lugging the drum down the garden!

Some WVO guys use a cold up flow system with a number of driums connected so drum 1 overflows into a pipe that feeds down into drum 2 near the bottom, that then cascades into drum 3, 4, etc.. Need a fair old bit of oil to fill the drums enough for that to work, be the idea is the oil takes a few months to migrate slowly through the tanks leaving nice dry clean oil at the far end. I'm too impatient to bother with that faff!

PM me if you want to have a chat over this stuff.

Craig.

cncfabs · 22-08-2013, 16:55

Quote:

Originally Posted by Fez_uk

Who was the one here who set up a few drums to do this? Search function hates small words like bio wvo etc so finding it hard to find the thread.

Got myself a shed, And some supply of WVO I want to filter and dewater (free electric

)

Wouldnt invest to much into wvo equipment Brussels is about to put a stop to people without waste managment licences collecting it its all going to be regulated

makeitfit · 22-08-2013, 17:53

Quote:

Originally Posted by cncfabs

Wouldnt invest to much into wvo equipment Brussels is about to put a stop to people without waste managment licences collecting it its all going to be regulated

Fook Brussels and the treasury, carry on Fez

Up the revolution

Fez_uk · 22-08-2013, 20:27

You need a waste licence anyway. You forget I live in wild wales.

arcascomp · 23-08-2013, 08:28

In England and Wales you don't need one for personal use, although many places will still ask to see one as they know they also are regulated and have a duty of care to dispose of the oil properly.

Sadly in Scotland we are under the watch of SEPA instead of the EA and they don't have the same exemption for personal use, although I do have an email from them stating that they would never chase someone collecting oil for their own use. Either way, it's about £150 for three years to get one and then your ass is covered, given the fact I topped up my tank to the brim with a couple of litres of diesel the other day - total of £20 for a full tank in a T2 - it soon pays for itself.

22-08-2013, 10:38	#1
Fez_uk Senior Member Join Date: Sep 2010 Location: Mid-Wales Vehicle: Maverick 2.7 - Patrol 4.2 Posts: 5,645	filtering/dewatering WVO Who was the one here who set up a few drums to do this? Search function hates small words like bio wvo etc so finding it hard to find the thread. Got myself a shed, And some supply of WVO I want to filter and dewater (free electric )

22-08-2013, 11:24	#2
arcascomp Senior Member Join Date: Jan 2012 Location: Edinburgh, Scotland Vehicle: 96 Mitsubishi Challenger! Posts: 775	In the middle of tidying up my system to make life easier. Currently I have one 205L drum with the top cut off (couldn't get a supply of clip tops that make this easy!) and a 22mm tank connector fitted near the bottom. The second drum has a standard immersion heater boss soldered in near the bottom, a 22mm fitting on the bottom, dropping through a central heating pump and being pumped up into the top via a pipe with a bunch of holes in. A bit of plumbing and a bunch of full bore 22mm valves to isolate/direct flow and finally a couple of sock filters hanging over a final resting drum gets me to clean and burnable oil. Not the best setup, but works for now. Basic approach: suspend an old bed sheet over the first drum (I support mine with a chicken wire 'baskets' to stop the edges of the sheet ripping), pour the waste oil through this. Best if you have the space to keep the oil settling for as long as possible to get the real manky stuff to drop to the bottom first and only pour off the better stuff. The bed sheet will filter out loads of stuff and also eventually clog up with semi solid fat custard. That stuff can be scrapped off with a ladle a few times before the sheet needs replacing. When there's a reasonable amount in the first drum, open up a valve to pump this stuff up into the second drum. When full (or at least fully covering the element with oil - watch this cos a bare element gets hot and can cause big bangs!) turn on the immersion heater and start pumping the oil from bottom to spray in the air into the top, oil only needs to get to 50-60 degrees and the water will evaporate while it's being sprayed in the air. The drum being topless and having fresh air blown over i by a normal fan will speed this. You being topless will only save on the washing machine usage as you gradually cover everything in waste oil! After a few hours pumping round you should be in possession of cleanish dry oil. Test a bit of oil in a hot frying pan, any water will sizzle or create bubbles as the oil gets hot, dry oil just sits there and eventually smokes. Wet oil will destroy your fuel pump/injectors so get this right. Once oil is dry, you need to filter it to 1 micron to stop blocking the vehicle filters. Only ever filter at ambient temps because hot oil will pass through and then form solids when it cools. I slowly pump from my heating drum into a set of sock filters suspended over a 30L mango chutney drum and let gravity do it's thing. This then empties into a 60L barrel I take to the car and fill the tank with. In cooler months, you need to thin the oil with either diesel or petrol. Petrol does this much better so you need less and petrol also strips out any residual water or other tiny floaty bits, so best to mix outside the tank a few days before pouring in.

22-08-2013, 11:34	#3
arcascomp Senior Member Join Date: Jan 2012 Location: Edinburgh, Scotland Vehicle: 96 Mitsubishi Challenger! Posts: 775	Phew! that was a bit of an epic! I am planning to clean up the system I have to lessen the steps and tidy the shed slightly, basing the system round an upturned hot water cylinder as it has a nice curved bottom (fnarr, fnarr) although for processing a decent quantity, weld a cone to the bottom of a 205L drum as the resulting plumbing can be easier. My plan is to still sheet filter and pump round in circles through a spray bar, but to then pump up into a vented (out of the shed) upside down hot water cylinder where using a venturi I will add the petrol from between 10 and 20%. I will let the oil cool a fair bit before this as hot petrol in a big tank does sound a bit dodgy! Once the oil and petrol are mixed up, turn it all off and leave it for a few days. Then drain the first few litres off which should be any settled sh1t3 and then filter the rest slowly as before. Oil with petrol added runs through the filters SOOO much quicker. For a spray bar, fit a bent spoon on the end of the outlet pipe in such a way that the flow of incoming oil to the tank hits the back of the spoon and fans out, cheapest solution probably to get good oil to air surface area. To maximise the life of any filters create a sock by stapling j-clothes together and put them in place to be the first filter - when they block up, remove and create a new one - much cheaper that way.

22-08-2013, 11:57	#4
Fez_uk Senior Member Join Date: Sep 2010 Location: Mid-Wales Vehicle: Maverick 2.7 - Patrol 4.2 Posts: 5,645	That's pretty much what I thought. Think my biggest cost will be a pump to transfer from drum to drum (and vehicle) and maybe another pump to circulate while dewatering and a heater. How come you don't do all the filtering on the first drum? Any advice on a cheap mains pump to circulate the oil when dewatering?

22-08-2013, 12:04	#5
arcascomp Senior Member Join Date: Jan 2012 Location: Edinburgh, Scotland Vehicle: 96 Mitsubishi Challenger! Posts: 775	If you're just moving veg oil and not bio, any old central heating pump will manage, but remember they need to be at the lowest point as they aren't self priming. With a bit of careful plumbing, the same pump will do everything, if the shed is too far from the car (as is my case) you need something else to get the fuel into the tank, I currently lug a 60L drum out to the street and then use a £10 drill pump off Amazon to transfer it. Must buy a cheapo sack barrow to save lugging the drum down the garden! Some WVO guys use a cold up flow system with a number of driums connected so drum 1 overflows into a pipe that feeds down into drum 2 near the bottom, that then cascades into drum 3, 4, etc.. Need a fair old bit of oil to fill the drums enough for that to work, be the idea is the oil takes a few months to migrate slowly through the tanks leaving nice dry clean oil at the far end. I'm too impatient to bother with that faff! PM me if you want to have a chat over this stuff. Craig.

22-08-2013, 20:27	#8
Fez_uk Senior Member Join Date: Sep 2010 Location: Mid-Wales Vehicle: Maverick 2.7 - Patrol 4.2 Posts: 5,645	You need a waste licence anyway. You forget I live in wild wales.

23-08-2013, 08:28	#9
arcascomp Senior Member Join Date: Jan 2012 Location: Edinburgh, Scotland Vehicle: 96 Mitsubishi Challenger! Posts: 775	In England and Wales you don't need one for personal use, although many places will still ask to see one as they know they also are regulated and have a duty of care to dispose of the oil properly. Sadly in Scotland we are under the watch of SEPA instead of the EA and they don't have the same exemption for personal use, although I do have an email from them stating that they would never chase someone collecting oil for their own use. Either way, it's about £150 for three years to get one and then your ass is covered, given the fact I topped up my tank to the brim with a couple of litres of diesel the other day - total of £20 for a full tank in a T2 - it soon pays for itself.