I have just finished converting my WMO heater to a two burner with the help from this site. Man this thing creates alot of heat and fast. I am an HVAC Tech. and I am really intersted in this easy to build heater .I am really intersted in heatwater to possible create a heating hot water loop for my house. After converting to the 2 burner I ahve noticed a increase in black smoke . I would like to see this thread keep going and interested in anymore ideas you guys have. Great work guys .

Scitt c. -- Good to have another person experimenting with this..

what style heater are you using, are you burning used motor oil in the double bowl unit, if motor oil - is the bowl easier to clean than the original burner, what type of burner were you originally using, is the new burner constructed from thick or thin metal, surprised to hear the bowl burner makes MORE smoke ?

I have been using the double bowl burner in the wood stove every day with no problems. since building the other Sanders style heater I have to say that the wood stove does not seem to be as efficient at heating as the Sanders heater, I suspect it has to due with the larger hot surface area of the vertical tank-type heater comparted to the horizontal wood stove type fire box ? Wood stove in an old, drafty house compared to the Sanders heater in a tight, well insulated house may also have something to due with it. The wood stove is also only burnt when I am present, this requires 3-4 hours of heavy heat to get the house warmed up from the cold overnight period (inside temps can fall to anywhere between 40 deg f to mid 50's overnight), I can then cut back on the fuel flow, end up burning someplace around 7 gallons of oil over 14-16 hours in the wood stove house compared to 5 gallons over 24 hours in the Sanders style heater in the other, much better insulated, house. Outside temps were in the low teens in daytime and low single digits F at night.

I think I have noticed that crudded-up bowls make more smoke than clean ones but haven't done any specific testing on this. There is a balance between the amount of combustion air being fed to the burner, amount of heat being lost up the chimney, the amount the stove is being cooled by combustion air, and smoke, sort of takes tweeking to find the best settings. I added a bit more combustion air to my single bowl burner today, was outside and noticed more smoke than usual from the chimney, opened up the combustion air damper a bit and the smoke dropped back to normal, the bowl has not been cleaned in a couple days and has a bit of crud in the bottom, may be that even this small amount of crud has more effect on how clean it burns than I realized. will swap to a clean bowl tomorrow and see how it goes.

I have just recently began monitering the temp of the burner tank outside surface while burning the single bowl burner, adding the additional bit more combustion air (slight dull roar to the flame now) may have dropped the tank outside surface temp down 4-5 degrees but even with the small amount of oil burning now (.16 G/H), due to outside temps being only around freezing, the burner tank outside surface temp is still around 180 degrees, house stays around the low to mid 70's. In the recent "zero" weather I was burning .20 G/H over several days (windshield wiper motor powered metering pump allows VERY fine tweeking of the fuel flow), this placed the burn tank outer surface temp around 250 deg, this also kept the temp inside the house someplace between 72-75 degrees f.

1.I am using te Sanders style (40 gallon electric water heater tank)
2.I am burning waste motor oil
3.The burners are constructed using the top and bottom from a 30lb refrigerant cylinder I am an HVAC/R tech and have tons of these laying around Im glad to find a use for them. The metal is pretty thick I would guess atleast 18 gauge it works great. I cut down the original carrying handle for the top burner legs .
3.The double burner is much easier to clean I ran it for 3 hours steady the other day outside in the middle of the yard with a 5 foot section of flue pipe attached and needs no cleaning hardly any build up burners are just black with soot.

It will be interesting to see how well the 18 guage steel upper bowl holds up, the first one I made was from 90/1000 thick steel propane tank material, it lasted about a month being used every day. The steel would shed large thin flakes of material when cleaning, as it got thinner over time it began to warp, eventually it got so thin that it began burning through. The steel bolt legs also flaked away at about the same rate. This was burning vegoil, I think used motor oil burns at a bit lower temp so it may hold up longer, will be interesting to find out.
The cooler burning propane tank steel lower bowl has held up fine, I am still using it after a couple months and it has only a slight warp from excess heat reflected from the fire brick.

If you used the handles for legs I suspect the lags are fairly short, with 2 inch legs on the upper bowl I found a lot of soot would collect on the bottom side of the upper bowl, caused by the lower flame contacting the metal, I raised the upper bowl up to 3 1/2 inches above the lower bowl and most of the underside soot went away.

The picture below is of a double bowl that I hoped would operate at fuel rates lower than a quart/hr, I hoped the thin lower SS bowl would be insulated from the thick steel bowl in the current Sanders heater, an insulated thin bowl should not loose heat nearly as quick as the thick open-to-air lower bowl that I have in the Sanders heater, it sort-a worked but the bowls would shift with heat and one of the top bowls legs would drop inside the lower bowl and spill it's fuel, don't know what caused the bowls to shift, may have been thin metal warping with heat or may have been steam seeping out of the fire brick, don't know, I did hear some "popping" or "bumping" from inside the tank when the bowls would move.
I went with the single bowl burner before testing this idea completely.

I now use the Sanders heater's original thick lower bowl as the shelf to support the current single bowl burner.

double_bowl-thin_bottom_bowl_on_f_brick-no_tank.JPG (20 Kb, 79 downloads)

This picture is of this same double bowl burner doing it's thing in the Sanders burner tank heater. The door is open so the flame is not burning quite as vigorously as when it is getting combustion air from the air inlet tube that terminates about one inch below the upper edge of the tank opening.

double_bowls_burning_in_tank-door_open.JPG (22 Kb, 80 downloads)

So what are you currently running as your setup I am still experimenting with the double burner .Your spacing seems to be greater than mine .I have actually put a tee in the oil feed line so I could feed both bowls simultaneously without the fuel trough. I am currently added bushings to the tee to get the feed for the bowls balanced.

As of know the top bowl will not puddle just burns instantly like this I can run at very low rates.
Still getting pretty good amount of smoke and have tried fan induced draft with no help.
Also just built a turk style burner and man this thing burns hot and clean almost no smoke but no low fire capabilities.So that wont work.

I would love to rid some of the black smoke and still keep low fire capablities any luck with you.
Thanks for all your help.

would making the turn burner physicall smaller create a low fire capability? How small could you go? A stainless egg cup and a stainless coffee mug? Smaller? Two bits of stainless pipe?

If you are getting smoke on the double bowl then perhaps you need less fuel to the lower bowl or better forced passage of the smoke from the lower bowl through the flame of the upper bowl? With sufficient combusiton air swirled in at the same time. The air feed pipe may already be able to supply this.

Scott -- bowl spacing -- Originaly I tried 2 inches, this caused a lot of soot to be generated on the bottom of the upper bowl, the lower bowl flame was contacting the upper bowl surface, this cooled the flame and it deposited it's remaining fuel as soot, sometimes up to a half inch in thickness. I raised the bowl spacing to 3 1/2 inches and this got rid of all but a very thin layer of soot over small sections of the lower side of the upper bowl. The latest upper bowl has 4 inch legs but the sooting is the same as the one with the 3 1/2 inch legs. I suspect this larger spacing is part of the reason it does not work well with low heat, too much air gets between the bowls and cools things down. Your close spacing may also be a source of some of the smoke, soot and smoke are pretty much the same thing, if a flame deposits soot it likely is also making smoke.

No top puddle -- That is what I see also, you have to feed a LOT of oil to get a pudle in the top bowl because it is being heated by the lower flame, that was the idea in the first place, this fast vaporization seems to reduce the amount of crud left behind and should also help reduce the smoke.

The amount of combustion air makes a BIG differance in the amount of smoke. I recently had to reduce the combustion air a bit during a blizzard with winds gusting to 45 MPH on my current single bowl burner (that discussion is here), the flame got blown out once during the night so I closed the combustion air damper and the flue damper down a bit, the bowl was badly crudded up the next morning and there was noticable black smoke from the chimney, I switched in a clean burner bowl and opened up the combustion air damper about an eight of an inch more, the flame yellowed up and the burner bowl is now on it's 4th day without needing cleaning, the extra air did reduce the burner tank surface temp by about 5 degrees but the house stayed fine with the lower 180 degree tank temp.

Smoke -- How much fuel are you feeding the burner, A natural draft drip burner is going to make some smoke, more fuel means more smoke. I am currently burning between .1G/H and .2G/h of veg oil in the single bowl burner, the .1G/H fuel rate makes almost no smoke, I have to stand and watch the chimney for several seconds to detect it, the .2 G/H rate makes a noticable bit of smoke when looking directly at the chimney but I have tried to see the smoke as I drive past the house and I don't see anything during a quick glance at the chimney. If you are feeding more than a quart/hr of fuel you will get noticable smoke with veg, I suspect even more from used motor oil, but I have not tried burning this yet.

The turk definatly will burn cleaner due to the extra air but it still makes a bit of smoke. Another fellow here is heating his shop with a turk inside of a large wood stove, feeding over a gallon/hour of fuel, it puts out noticable smoke and a lot of heat. The flame is mostly white but there is still smoke. I have considered trying to build a small turk using the small throw-away propane torch cylinders, use the taller thin one for the center burner chamber and the shorter fatter one for the outer air chamber, even made up the cylinders, but have not finished this up, may work, don't know til I try it.

Ant -- Smaller bowls -- Might work - problem I see is with the need for the 3 1/2 inch spacing to reduce sooting of the under side of the upper bowl, have to try it to know. I am having such good results with the thin single SS bowl burning at the low fuel flow rate (.11 G/H now, reducing it even more as the outside temps rise) that I have not had much reason to test this idea.

Today I added a 4 inch computer fan to the top of the 4 inch air intake and wow what a diffrence in smoke output it is almost not in existent. This defeats the prpuse of natural draft I really dont want to power anything. I have about 6 inches between the bottom of the intake annd the top of the burner. Is this to much also the pipe is the same size all the way down would it be necessary to reduce down to get more turbulence.
I see you are using the single bowl SS did you insulate it?
Also I am just testing this thing out I am ordering a metal 24x36 double garage that this will be heating I live in North Carolina it reached 60 degrees today so weather here is always pretty mild. It is setting outside with only about 6 foot of 6 inch flue pipe connected.

AHAA - Now the excess smoke problem makes more sense. Once you get the heater connected to a good length of flue pipe that goes up at least a couple feet higher than the highest point of the roof you will get more draft than even the 4 inch fan is likely making.

6 inches between the bottom of the air intake and the burner should work fine, Sanders used 8, I am using 5 in the wood stove (4 was too close and the end of the thin tailpipe tubing showed burning). This distance does not seem to be terribly critical as long as there is enough distance to keep from burning the air tube away. I have found that the end of the drip tube survives better if it is at least 4 inches up inside the lower end of the air intake tube. Every time you open the door on the heater it disrupts the draft of air coming down the air intake tube and you get a small amount of heat and smoke going back up inside the air intake tube, this can crud up the lower end of the fuel drip tube over time. I have not seen any reason for the pipe to be reduced in size, all of the info I have read uses an air intake tube that is the same size end-to-end. Diameter does not seem to be realy critical either, Sanders used 4 inch, my wood stove insert is using 2 1/4 inch, my Sanders style propane tank heater is using 3 inch pipe, they all work fine as long as you have some way of adjusting the draft through them. The draft adjustment can be done using only the ready-made flue dampers but having controls in both the air intake tube and the output flue gives a bit more "tweekability". Sanders did not use a flue damper, just a piece of metal laid over the intake of the air intake tube, my wood stove only has a flue damper, the propane tank heater has both, they all make heat.

SS single burner bowl -- I originally stuffed the canister below the burner bowl with house-type fiberglass insulation, over a couple weeks this insulation sort of "melted" into a 2 inch tall crusty lump in the bottom of the canister so I removed the fiberglass completely, can't tell any differance. The burner bowl sets at least half way down inside the canister anyway, seems to be working fine using only the empty canister to hold the burner bowl.

In your climate the heater should work just fine heating the garage, especially if it is insulated, probably even if not. 24 X 32 is about the same size as my house and .2 G/H or less has kept it in the mid 70's inside even in "0" outside temps. The house has a concrete slab floor, it took about 7 days before this slab came up to temp and quit sucking up heat. Once it warmed up the house got much hotter with the same amount of fuel being burnt, this happened pretty quick over about 12 hours on the 7th day. The slab has kept the house warm for several hours the couple times the flame went out, Now I undertstand why folks like heating a slab with internal water pipes, nice stable heat.

quote:

Ant -- Smaller bowls -- Might work - problem I see is with the need for the 3 1/2 inch spacing to reduce sooting of the under side of the upper bowl, have to try it to know. I am having such good results with the thin single SS bowl burning at the low fuel flow rate (.11 G/H now, reducing it even more as the outside temps rise) that I have not had much reason to test this idea.

Actually I was talking about the turk burner but it should help with the bowls as well. Would the 3.5 inches be constant even with a smaller lower bowl with a different flame pattern? And your distance could be somewhere between 2 inches and 3.5 inches. 3.5 could be more than you need just as 2 inces is less than you need.

I found that a 3/8 inch thick piece of iron was an easy to clean to part when I use a small air chisel. It will take any abuse without much metal loss and it retains the heat to continue vaporizing my used oil while I am adjusting the flame at startup. If I turn down the fuel too much it gives me time to readjust before the whole shebang shuts down.

Used motor oil as fuel -- I have just burnt my first 5 gallon of used motor oil through the double bowl burner insert in the wood stove. This oil lit and burned just about like veg as far as the flame is concerned but, as Murphy stated, it does like a lot more air than veg to burn without smoking a good bit. I run the flue vent about half closed with vegoil and see only a small amount of smoke, I now have the flue vent completely open for this oil and there is still a noticably larger amount of smoke. Part of this problem may be that my combustion air inlet tube is only 2 1/4 inches in diameter, this allows only about 1/4 as much air into the burn chamber as the sander's 4 inch tube does. This smaller tube may simply not be able to supply enough air for the oil to burn as clean as possible in a drip-fed vaporizing burner. I will eventually make up a larger diameter air intake tube and see if the smoke is reduced.

This oil produces a LOT more of the soft ash type deposits, it only took a couple of hours of burning this oil for the soft ash to completely plug up the lower bowl drip hole in the fuel shoot (NEVER had this happen burning veg), once this happened the oil pool in the upper bowl got large enough to overflow around the outside and drip down into the lower bowl, glad I made the lower bowl a bit larger in diameter than the upper bowl. The upper bowl is now pretty well covered with what appears to be soft ash and the flames are completely covering the surface of the ash in this upper bowl, will have to see how this cleans out once the bowl cools down over night.

Not perfect but it is making nice heat. There was a bit of used motor oil smell from the stove til it got completely up to temp, don't smell it now though, hopefully I did not just get used to it.

Burning used motor oil -- OK, I have burnt another 15 gallon of motor oil, -- the double bowl burner is not really compatable with it --and I don't think it is nescicary or desierable. The flames from motor oil are much longer/larger than the flame from veg. My veg flames are mostly under 4 inches in length so placing the upper bowl 3 1/2 inches or more above the lower bowl is enough distance that most of the veg flames don't contact the underside of the upper bowl. Veg also needs much less combustion air to burn pretty clean, motor oil likes LOTS of air, the center opening in the upper bowl is way too restrictive for enough air to get to the lower bowl when burning motor oil, this causes the lower bowl to make a good bit of smoke burning motor oil, you will also get a LOT of soot forming on the underside of the upper bowl due to the much longer flames from the motor oil contacting the relativly cool metal of the upper bowl, in only a few hours of burning the soot on the underside of the upper bowl was about 2 inches thick and looked like soft hair, this made the lower bowl make even more smoke. The top side of the upper bowl also got crudded with soft ash in only a couple hours, most of the bowl was covered with 1/2 to 3/4 inch thick sorta-soft ash.

I pulled the upper bowl out of the stove and used only the lower bowl, WOW, much better, The flame is around a foot tall and I was even able to close down the flue draft to about 30 degrees rather than completely open, this holds a good bit more heat inside the stove. Even with this reduced amount of combustion air there is very little smoke being produced, maybe even less than when burning veg in the double bowl (at least by looking at the flame inside the stove, have to wait for daylight to know how much smoke is actually coming out of the chimney). I did NOT change the position of the lower end of the combustion air intake tube, the lower end of the conbustion tube is about 10 inches above the single bowl and it is working just fine.

This single bowl burner works as described in the Sanders article, there is a pool of boiling oil in the single bowl and this pool of liquid seems to be making much less crud than the double bowl burner, there is crud building up but nothing like the amount that was being produced with the double bowl burner. The pool size changes size depending on the amount of motor oil being fed to the burner.

THIS IS GOOD - I can, and likely will, spend more effort to collect used motor oil for heat, it will be much nicer to be able to store the always-liquid fuel in a large outside tank and pipe it to the burner rather than have to carry 5 gallon cans of solid veg inside for melting before it can be burnt.

I have burnt up most of the used motor oil I had on hand, turned out the farmer I got it from sorta snookered me, the bottom 1/3 of each barrel was antifreeze.

Burning the used motor oil in a large single bowl has been working well, after 12-15 hours of burning I end up with a 5-6 inch diameter crusty pancake in the bottom of the bowl, there is usually a divit in it's center where the oil was directly dripping and burning. Once this crud developes you no longer see an obvoius liquid fuel pool but there is flame rising from the entire surface of the crud, I assume the crud is porous and is working like a sponge and soaking up the fuel.

Watching the chimney the UMO does make more smoke than vegoil does, even with the flue damper and the air intake completely open, at least in my current wood stove setup. I have not increased the 2 1/4 inch diameter air intake tube yet so this restriction may be part of the problem, I am hoping the weather warms up before I actually get around to trying this, getting real tired of freezing weather.

You need MUCH MUCH more combustion air for waste motor oil.

Just an estimation, but the amount is like 3 times more than what is needed for a clean burn of veg oil.

Hi Tim

although I've read on and off for awhile now about turks and babbington burners it's only recently I decided to look into it a bit more and have a go at making something to burn my wvo dregs, so finding your write ups in this thread here is great and I also read the thread mobius posted on his version of the babbington.

One or two things I'm still trying to visualise on your twin bowl burner are the oil feed shoot, does it protrude from the top bowl into the central air supply tube and have a hole in it to leak oil into another shoot directly below it for the bottom bowl?

does the central air supply tube deliver all the air to just above the bottom bowl or is there an air supply to the top bowl also?

sorry if you keep having to go over this but I have tried to figure it out from the pics and re-reading the info.

have you ever tried burning biodiesel glycerol by product at all?

Chug

needed air -- I suspect my 2 1/4 inch combustiion air tube is not allowing enough ait for a clean burn of the motor oil, I will try a larger one when I get the time.

Fuel shoot -- The upper bowl is the only one with a fuel shoot or an air passthrough opening, the lower bowl is simply a bowled container, the oil drips in to the shoot, some runs down into the upper bowl, some drips through the drip hole, the hole is out over the opening in the air passthrough opening of the upper bowl so the fuel drips down through the air passage opening and drips on to the surface of the lower bowl in the area under the upper bowl's air passthrough opening.

The combustion air comes down through the air inlet tube, this tube ends about 6 inches above the upper bowl. This input air spreads out a bit as it exits the tube so some of the air blows on the upper bowls flame and some of the air passes through the upper bowl's center opening and reaches the fuel in the lower bowl.


Wet motor oil -- The motor oil seems to hold more water, maybe it is antifreeze, than veg, it can be a bit of a problem to get a cold single bowl in a cold stove using this oil, I had the flame go out 3-4 times until the stove got up to temp. Burning about a cup of diesel in the bowl prior to starting the drip finally got the stove warm enough that it stayed lit with this wet oil.

Thanks for clarifying that Tim

have you got an old PC fan you could try for more air?

Chug

I have been experimenting in my spare time this week with a simple pot burner made from a biscuit tin and dog food tin, the dog food tin sits inside the biscuit tin and has air holes 25 - 50mm from the bottom, the biscuit tin has an air supply tube fitted to the side of it (either hair dryer or PC fan to supply air), a simple gate valve and copper tubing supplies dripping wvo to the central pot (dog food tin) I start on paraffin and then when it's been going for a minute or so open the gate valve and start dripping wvo into the central pot, it burns a little smokey until it gets some heat in the metal then it clears a little, then I an add some air and it gets going much better and loses some of the smoke.
Yesterday I decided to drag my small petrol compressor out from under the pile of junk I call my workbench and fire it up and just using the attachment for blowing up tyres and proceeded to blow compressed air in, adding it in through the air supply to the biscuit tin helped a bit but eventually the flames started dying out, so I then tried adding air at slight angle from the side of the central pot and wow it made a huge difference with large flames licking up, then I tried from directly above and nearly burnt my hand that was holding the tyre inflator as the flames instantly turned into a roaring jet it was very impressive just from a couple of old tin cans, when I collect some more junk and scrap I will have a go at bodging together a mobius upright style babbington.

have a look at some pictures
http://www.biofuel-uk.net/A.jpg = first lit on paraffin
http://www.biofuel-uk.net/B.jpg = now burning wvo
http://www.biofuel-uk.net/C.jpg = flame on wvo in the dark
http://www.biofuel-uk.net/D.jpg = now burning wvo + PC fan supplying air
http://www.biofuel-uk.net/E.jpg = flame on wvo + PC fan in the dark
http://www.biofuel-uk.net/F.jpg = now adding compressed air at the side
http://www.biofuel-uk.net/G.jpg = now adding compressed air from the top with tyre inflator

Chug