Updated waste oil heater

[robotmaker]

This is a variation on the MEN (Mother Earth News) waste oil stove from 1980.  Many of you may have seen that article and the subsequsent postings from that guy in Canada.  I gotta tell you, I tried the original design, and the Canadians mods, and what I ended up with is far superior to any of them.  Attached is a quick sketch.  Let me know if you need more detail.  The burner assembly I made from two stainless steel electric motor housings (cans) with the guts (windings) removed. Gotta be stainless, or you will be making a few of these assemblies.  Not that they are hard, just time consuming. One is just a larger frame size than the other to obtain the "plenum" around the inside "can" which I call the burner.  There are a series of 1/4" holes drilled around the inside of the inner can, approximately 16 of them, and then a few at the bottom in about the location shown on the sketch.  Drill these before you weld the cans to the bottom plate. Then fabricate a ring to enclose the top of the two cans, from inside to outside can. Weld the 1 1/2" pipe to the outside can after cutting the appropriate size hole for the exhause pipe.  I made the pipe leading into the tank out of a size which slips over the one used on the burner assembly.  No air-tight necessary here as when it's burning, it is a positive pressure so you don;t have to worry about fumes coming back out the blower.  

Since it slip fits into the pipe leading in from the blower,, it is extremely easy to remove, chip out the residue left from the burning oil (and you WILL have residue) and slip it back in.  

I used an adjustable orfice (kind of like a gate valve) for the valve instead of a needle valve, it keeps the clogging to a minimum.  also, it is placed AFTER the pre-heated oil....much easier to adjust the heated oil rather than the sludge that is going into the pre-heater coil made from 3/8" copper line that is wrapped around the chimney pipe.

Lets see... what other tips can i give you... oh yah....make sure you have some speed adjust capability to the blower.  The one that was out of the car works just fine for me.  I usually throw a piece of oil soaked paper towell (not dripping wet) in the burner assembly, turn on the drip feed to a good rate, light the paper on fire, and the blower on low speed.  

As soon as its going at a good clip, turn the blower on medium speed and katie bar the door.  The outside of my stove gets up over 550 degrees F, and keeps my 120 sq ft shop toasty by having the gate valve open only a half turn.  I can make the outside of the heater glow red, but it will chase me out of the shop.  Now lately it's been pretty warm here in Arkansas, but today it dipped down pretty far.  It'll be a good test of the critter here tonight.  I still don't trust it going all night without attendance, because I am still pondering filterint the oil to prevent clogging of the supply line. I don't want to come into the shop in the morning with a puddle of oil on the floor.  although, the saving grace here is that if the fire does go out... the flow rate slows severly.

thats about it for now...unless anyone has any more questions...I think I already mentioned that my local junk yard is missing a few GM blower motors (heh heh)

rj

robotmakr@aol.com

[robotmaker]

Jeez... so much for proof reading the story... It's a 1200 square foot shop...not 120!  and here's the picture..  

[dburt]

Thanks for the update robotmakr, I have two questions:

  1.  Where in the world are you finding stainless motor housings?

  2.  About how many hours could you run before chipping out residue?

Dave from PA

[robotmaker]

well... I cheat a little, cause I work for a major motor manufacturer.  And our washdown duty motors are made of all stainless steel...But if you substitute the cans with some thicker pipe, it should work just as well... I mean, it doesn't take that much time to make one of these burners.  I just noticed that the cold rolled version of the motor band lasts maybe a couple weeks before you start to see signs of burn thru.  

second question... i usually clean mine out every day, since it is so easy to slip in and out...but if i wanted to burn it 24/7, i guess it would last a couple days.  I guess I have to try it sooner or later, it's getting cold, and I have stuff in my shop that I don't want to freeze up on me

later

rj

[Norm]

   You're afraid of leaving it unattended? Couldn't you fix an overflow so if the flame went

out the excess oil would flow into a steel pan underneath with a float switch connected to a solenoid valve to the inlet? another thing that crossed my mind, a gas burner inside this stainless steel burner, you could turn it on for about 10 minutes every day and burn the carbon out ...just like an oven cleaner?  How many quarts an hour...maximum does this little jewel use? Have Fun! Keep Warm! ( :>) Norm.    

[robotmaker]

Norm,

Thanx for your response to my project, and at the risk of sounding flip, Yes, there are several things I can do to prevent catastrophy, along with what you mentioned.  But the intent of my posting was to get the info out to other people who want to try heating with used oil.  Like I said before, the designs I have tried (and I've tried a bunch) this appears to work best.  Now before I get any angry comments or opinions of the opposite to that statement, I want to clarify a thing or two.  I mean that for a "gravity drip" system, this appears to be the best solution I can come up with.  Atomizing the oil will help with cutting down on the buildup of crud inside the burner, but adds complexity to the system.  I don't have a bunch of fittings screwed together, nor expensive parts to run this.  I pretty much cobbled it together with junk parts.  That to me was the challange.  Last night it was down in the low 20's here, and I ran the heater a little hotter than I would normally.  I was running about 450 degrees F on the chimney which made the outside skin of the tank extremely hot.  I can't measure anything over 550 F because thats the range of the hand held I have, but upon opening the thing up this morning, I found that most of all the residue was white this time.  So my findings are: The hotter the burn, the less contamination of the burner I see.  I haven't seen this in the past, because the thing puts out SO much heat, it makes it uncomfortable in my shop.  So cutting down the oil flow, just made the buildup problem worse.  

Anyway, if anyone is interested in more details, I'm willing to help.

rj

[Gordy]

rj,

    Allways want MORE MORE MORE.........

    Also had a thought. Sence you've gotten less build up at higher temps, would it work to build a smaller burner? My thinking is that the smaller burner would have to be run harder/ hotter to put out the same BTU's.

    Also wondering how much if any smoke you get out the chimny.

Thanks ,

Gordy

[wdyasq]

I've had similar thought about building a very small oil burner that would need to run at full tilt.  My thought were to use short sections of SS pipe from a muffler shop for the burner assembly.

Ron

[robotmaker]

Gordy,Ron...

No smoke at all.. even at startup, all you see coming out of the chimney is the heat wave.  I had tried a few different size burners.  The smaller ones just clog faster, but now with the elevated temps, I'll have to see.  Not too sure about the logic here for using a smaller/hotter burner.  You can only slow this oil down so much with the feed line.  When you try to control the drip with lets say the 1/4" line, it's not consistent, rather you don't get a consistent drip or flow.  I told you I tried em all !  Seems that the viscosity of oil thru the smaller lines just doesn't flow well unless it's under pressure.  Remember, I said I was tryin to do this with as little outside control as possible.  I just may have reached the limit without installing some intelligence on it.  

rj....(I'm keepin warm tonight...for free)

[RobD]

RJ,
Thanks for the illustration.
I talked to my industrial plumber friend and he said the probelm is soot build up. He said he has a commercial one with some kind of low pressure injector system. I think for me the problem might be getting the waste oil. He in cold climates I figure used oil is still a primium.
RobD

[Norm]

 Could you go into more detailed pictures of your burner....I'm really intrigued by waste oil burners...as I was born and raised in the era of kerosene (coal oil) and was always fascinated by the old wick kerosene burners on cooking stoves where they had something like 3 perforated sleeves nested inside each other the chimney surrounding the whole affair once everything got heated up it burned with a nice blue flame.
We had a coal burning furnace with a loop of 1-1/2 inch steel pipe (the hot water heating element...optional equipment) a 40 gallon water tank alongside. When summer came we had a little stove with a domed water jacket to heat the water. Once you got a good hot little coal fire going and had some nice red hot embers for some waste oil to drip onto with the draft adjusted just right it made an excellent fire,burning with an almost white hot flame!


Well hope I haven't bored you with all this rambling. I'm having a hard time locating an electric water heater tho' may have to make do with a gas water heater for the shell. Whatever, but still it's fun! ( :>) Norm.      

[robotmaker]

Norm,

I'll try and attach a new sketch of the burner assembly.  It is a weldment with a full bottom.  The 1 1/2" pipe is welded to the side, about as shown, with 1/4" holes drilled in the INNER tube.  I made 32 holes about in the middle of the circumference with about 8 or so at the bottom around the circumference. I am going to try as you suggested tho, with another level of holes further up towards the top.  Maybe make them smaller size, maybe 1/8" or so, as soon as I can round up a couple more motor cans.  

Rob D,

I used the gas heater tanks for wood stoves already.  I like the tube that runs up the middle, because you can just hook up a blower to the bottom, and blow hot air right up thru the middle of whatever is burning inside, and get forced hot air.  In this design, you could even use it as the downtube guide for the oil stream.  You will have to cut it off at the bottom and weld shut the hole in the bottom of the tank tho.  I actually put a 3" tube inside my present stove, that acts just this way, as a heat exchanger.  I fixed a squirrel cage fan to the inlet (near the bottom of the tank) and put a 90 degree elbow on top and point it wherever I want the 140 degree hot air to go.   Works great.  

rj

[robotmaker]

sorry. wrong drawing...

[Oilburner]

Lose the bottom holes...

Inject the air tangentially as per the "Turk Burner"

http://ww2.green-trust.org:8383/2000/biofuel/turk/

put a STEEL cat food can in the bottom (of your existing set up) and drip the oil into that. No more chiping out gunk, pull it out and throw it in your woodstove to "re-cycle" it.... The gunk burns out but the can stays usable.

What you have built so far is a "pot burner" in an enclosed stove.

Now, as to it being too hot... heat water with it somehow and store this hot water in something, don't use the stove to directly heat the space, use the stove/burner to heat water and use the hot water to heat. That way you can just be there to monitor a 1 hour intense burn of let us say 2 gallons of oil. That is about 130,000 x 2 BTUs (260,000 but let us say it is all less than 50% efficient so you get 100,000 BTU from a one hour burn) If you pump that water through radiators and use fans then you may get 10,000 BTU/H for ten hours out of a one hour monitored burn.

Yep you guessed it. I have a reason for giving you ideas. I can't weld, I have a need to heat a greenhouse for maybe 2 months in spring and 2 in fall, I don't want a heater in there, I will not use electric/oil/propane and I want the furnace/boiler/combuster like the "Outdoor Wood Burning" systems you see...

I am currently running tests using unenclosed burner systems, trying to develop something I can build into a kiln/boiler system.

Anyway that was a long post!!!! Maybe the point was aim for a very high temperature and "clean" burn (high temp and clean go together until you get to the high temperature where you form NOx......... that is another story!)and release the heat thus formed on demand.

[robotmaker]

Oilburner....

Finally, someone I can relate to.  Where should I start? Since this post WAS in the rants and opinions section, I guess it's allright to just sound off...First, I take it you meant to not have the bottom row of holes in my burner assembly?  Second, do the holes have to be drilled at some other angle to the assembly other than 90 to get the tangential effect?  or by just angling my inlet tube would do the same thing?  I went to, and had seen Turk's burner before, be he never followed up on his findings, so I thought I had been left alone to do all the research on my own. What effeciencies/benefits are there to the swirling of the burning of the gasses?  I like your suggestion on the indirect heating method, but this was a shoestring budget project, and in actuality, replace the wood burner I had in the shop.  I like the idea of heating water, probably putting it in yet ANOTHER junk hot water heater, to then circulate it thru a few strategically placed auto radiators (which I just happen to have a few) but once again, just adds to the complexity of the project.  I'll have to ponder that one.  Quite frankly I didn't want to become a slave to this project, but I do love to tinker with it, as you may have seen by my previous posts.

DUDE !  I can weld up a storm.  Since I am also into building hot rods, electric bar stools and the like, I have just about every welder known to man. DC/AC stick, heliarc, mig and even own a little plasma torch (the only way to cut metal).  If you really need me to weld you up a burner, let me know.  I'm sure we can work something out.  Last but not least, is where we may disagree, I have tried burning peanut oil in this assembly.  It works, but takes longer to get started, and consumes more oil to get the same results as far as heat output I think.  I am not sure about the numbers, but I don't think there are as many BTU's in a gallon of peanut oil compared to a gallon of crankcase oil.  I did melt some aluminum with it tho, and will probably do that again real soon.  I like the fact that the peanut oil seems not to leave a residue at all, so in some respects, I like it a whole lot better.  It even smells better.  I haven't looked into going to McDonalds or Burger King yet, but I thought I read somewhere that there is money in gathering this waste product from the larger users, filtering it and selling it to third world countrys?  Maybe just a rumor.  

I hope to hear from you again.

rj

[Astrofuelhead]

Got to hand it to you robotmkr this is a fantistic way of heating a shed. We need a sketch of the burner can you help me out.

Astro Ireland.

[robotmaker]

Astro,

I put a couple sketches on the board here.  Do they help?  If you need more detail, let me know.  Just so you know, I am heating a 1200 sq ft. building with this setup.  

Some feedback that I have from the last couple days is:

I tried the swirling burner that Oilburner suggested as a variation of the Turk burner, and I found that it gave me no benefits or improvements over my original burner which was just pumping the air into the assembly straight in (and not swirling the air or feeding it in tangentially).  So, Oilburner, if you read this, let me know if I did something wrong?

rj

[bjorn773]

Hello all, I just joined this forum. I've been reading through all of the posts regarding the Mother heater. I am contemplating a different twist on the whole idea. I have a wood burning stove that I just installed a few months ago. I am burning wood much faster than I anticipated, so I would also like to be able to burn waste oil in it. I have found a couple of different designs on the web. One is basically a reservoir gravity feeding into a coil of copper tubing. The tubing is coiled about 1.5 inches in diameter by a foot or so long.  Then the end of the tube is crushed to form an injector of sorts and pointed into the inside of the coil. The assembly is placed inside a wood burning stove. A wood fire is used to get the aparatus up to temp and then the oil begins to burn on its own. The second design is a crude burner if you can call it that. There is a heavy gauge pan in the bottom of the stove and the oil is gravity fed from a reservoir and drips into the pan. Wood is again used to heat the pan initially then the oil in the pan ignites and will continue burning. Any thoughts on these designs? Would simply dripping the oil onto my burning wood create the desired effect? I would like to be able to easily remove the burner assembly for strictly wood burning in case I run out of oil. I am an auto mechanic with access to a lot of oil, but have never played with waste oil burning before. It sounds like a great way to supplement my wood burning... or maybe my wood burning could supplement my waste oil burning if this goes well. You seem like a group that has tried about every design out there, and attempted to improve on them. I will greatly appreciate any advise from those who have gone there before me. Thanks, Bjorn

[robotmaker]

Bjorn,

You can just drip oil into your wood fire and extend it just fine.  Since you are commmitted to wood anyway, the residue left over from the burning oil can be taken out with your ashes.  I went the way of just burning oil for several reasons.  I got tired of chopping the tree, cutting up the tree, transporting the tree, splitting the logs, stacking the logs, stoking the fire and taking out the ashes, not to mention anyone could tell i was buring wood when they walked in the house.  With the stove I made, you can't smell anything.  I now go to the local jiffy lube and get a few 55 gallon drums worth out of their holding tank for next to nothing.  I built a little oil pump from a chevrolet v8 engine, powered by an electric motor, that pumps it fine out of their tank, into my drums, and then out of the drums into the holding tank in the shop.  A whole lot less work than the wood route.  I know people who just drip oil on their wood, and it does extend the burning time tremendously.  But, watch out for the combination of the hotter oil fire and kreosote buildup in your chimney.. I think I would start out with that cleaned first.

rj

ps.  I tried that wound copper tubing burner once.  It was a disaster.  I've tried several of them, most of which don't deal with the residue left over from burned oil.  That's why I think the burner I finally used works ok.. I am committed to cleaning it out before I burn it each time, and have no problems at all.

[bjorn773]

RJ, Thanks for the response. I tried the dripping method yesterday. Because of my stove design, I had to introduce the fuel from the side of the stove. There is a secondary burn chamber above the other and would have been a bear to drill through everything. Anyway, I first tried coiling the tubing around the stove pipe several times to preheat the wood. This made the oil so volatile I could not control the flame at all. I even have a valve mounted after the "preheater" to control flow. Then I removed the preheater section, which resulted in better control of the oil flow. One thing I have noticed, I end up with a flame right at the oil injector. I guess it won't hurt anything, other than cooking a lot of oil onto the injector. The injector will need to be cleaned everyday I guess. Still, I am having difficulty getting a clean flame. Is the secret to the hot, clean flame you have achieved in the forced induction of air? I don't believe that is possible with my stove unless I cut a rather large hole in the side. The total height of the combustion chamber is only about a foot. I did try putting a pan under the injector with a 1" diameter x 4" long solid rod in the middle. My thinking was that the rod would heat up and the fuel would burn right on it. What I ended up with was what reminded me of a burning oil field. Very smoky and sooty. I suppose the bottom line is the drip method will have to do unless I want to build a new stove like you have. Thanks again for the help and if you think of anything I might be doing wrong here please let me know. Bjorn

[bjorn773]

RJ, Me again... I can't get enough of this stuff. I have been looking at your burner design and how to incorporate it into my stove. I just have a few questions. First, does the height of the burner seem to make much difference? I imagine you have tried many. My stove is maybe 12" tall inside and I'm wondering if I can get away with a shorter version of your burner. Second, does the burner contain most of the flame? Being that my stove is so short inside, I'm hoping the flame would more or less stay in the burner assembly and not melt the top plate of my stove. Third, how heavy gauge is the burner assembly. I do not have access to stainless, but would 1/4 or 5/16 wall pipe work? Fourth, how long is the bolt that the fuel burns on? Or rather what ratio of burner height to bolt length did you use? Thanks in advance, bjorn

In my previous post I stated I preheated my wood... incorrect, I preheated the oil with the coiled tubing. You probably figured that one out anyway.

[ealasimi]

I just found this site, I have been burning waste oil for a couple of years in my wood shop. Started with the MEN plan and it has grown into present one that is disscussed at attached site.

http://www.tractorbynet.com/forums/showflat.php/Cat/0/Board/oil/Number/333446/page/1/view/collapsed/
sb/5/o//fpart/1

I will look forward to this site.

[robotmaker]

Ealasimi,

Thank you for the link, but what a shame.  I see what those guys are doing, and they are trying the same thing I did, with the mods by that Canadian guy to the original MEN design.  I tried to email one of them to let them know I had a better working unit than that one but it appears you have to join THEIR group.  If you know those guys, let them know for me that I have a solution for them?  I would gladly share my findings and design.  I just cringe at the thought of someone buying a commercial unit.  I too am a scrounger of parts, and try to do it for next to nothing if I can.

They can get me at: robotmakr@aol.com

rj

[stnickstoys]

Hi rj,

Nick here, finally found my way here from the email you sent me.  I like what I'm reading so far.  Been really busy, finally had a chance to sit down and surf today.  Cold weather has me thinking about my MEN furnace mods again.

I saw your drawings posted so far and have a couple questions, I have the MEN built, intake tube in the middle, oil dripping down it onto the burner as in the MEN plans.  Was wondering, with your "swirl burner design, when the air blows in and goes around your burner, and into the holes in the center cylinder of your burner, doesn't it want to go up the old intake pipe rather than the chimney?  

Another question, do you have some short of structure in the bottom of your "swirl" burner as in the MEN burner, metal plate with holes etc or do you just drip the oil into the bottom of the double walled burner?  

Could you take some pics of your burner to add to the detail of your drawings?  

I'm enjoying burning used oil as I have lots from my tractor business but not satisfied with the efficiency of my original MEN heater.

Any more detailed drawings or photos would sure help me.  

Thanks again for the email and great posts here.

Nick in WI

[ForrestGump]

self starter

[robotmaker]

Forrest,

Thanks for the drawing.. and here is yet another variation of that original MEN design, with Bruce from Ontario Canada mods in it.  I am STILL of the opinion that his variation, even tho it works fine, is difficult to clean.  And I know I have to chip the leftover ash and deposits out of my burner each day.  That is why I made it so that you can take it out easily, for cleaning.  I've tried running it hot just to get those deposits to burn up better, but it just doesn't do it.  Another point, is that I still like to pre-heat the oil too.. it makes it easier to regulate the flow with the valve in the heated oil path, hence I still used the MEN version of wrapping the copper tubing around the stovepipe.

Once again.. just my 2 cents

rj

[ForrestGump]

i wish i would have found this site 3 months ago when i started working with WVO.. i wasted so much time trying to figure things out. i have turned an old oil fired boiler into a wvo boiler by preheating the oil just before it enters the gun. i am going to use it to heat my pool and hottub this summer. i have biult 5 diff. MEN stove     converted my woodstove to burn wvo.   next i am buying a diesel gen and truck to burn wvo. the truck to haul the wvo. i am also working on a fireplace insert to burn waste oil. alot of friends have fireplaces.. well i hope everyone is have as much fun with this as i am..

   thanks all for your info....Forrest Gump

[ForrestGump]

the hot surface ignitor only works for about 4 days so dont waste your money    sorry

[ratkilr]

 Thank you robotmaker! I have been toying with my oil burner since last year. It started out with the men design. I have tried every one that I came across. Just found this sight last week. So I tried your setup and it is a winner. I wanted something that would work without pumps, nozzles or fans but I dont mind having to use a small fan if that is what it takes.

 I did not have spare blowers in my parts pile so I bought a $10 hair drier and wired in a dimmer switch in the cord. Now instead of three fan speeds I can infinately control the air.

 Only down side is my stove puts out so much heat I need to install a larger heat exchanger as flue temp is kind of high. My shop is 3200 square feet with r-19 insulation and I beleive this stove should be able to heat it.

 Thanks, Robert M.

[ratkilr]

 I am real happy with rj's burner desighn. Like I said before I tried many and have tried to alter them to work. Some worked but not good enough for for me. Not enough heat output and too much smoke. Oil was reformulated after the men design. That is why they no longer sell the plans for their oil burner. It worked well before the oil companies changed the oil formula. They added an anti-flashing agent to the oil because the new four-bangers had to work harder.

 The local utilaties (montana dakota utilaties) have nearly doubled their price for natural gas for the last two years. Last year I said enough was enough.

 The only negative to this burner design on my stove is a little oil spatter buildup on the roof of the stove. I think I have a simple solution for that. Other than that it runs stable with good heat output. No smoke in my shop or outside.

 I am willing to try other designs but this one worked for me. My stove has a lot of mass to it. I could not find an electric water heater in the dumo so I went to my metal supply place and dug through their scrap pile untill I found a chunk of pipe with the same length and diameter as the men stove. Only thing was it was 1/4" thick pipe. I cut a top and bottom for it out of the same thickness. It is an extremely heavy stove. Nice thing is that after I shut down the stove it is still too hot too touch almost two hours after. So it is still radiating heat for that time. This stove will not burn out before I do!

 I have one little change for the burner but right now it is still the best so far. If anyone has any new designs please let me know. I would like to try any before winter comes again.

[ForrestGump]

just to let you know today i got my old oil fired boiler all put back togeather and i am useing WVO as fuel to run the boiler . It is plumbed to our swimming pool and heating just fine. this winter i will use it to heat the house

[powersavers]

yep, it is a listed commodity, called yellow grease. this is any waste oil from rendering plants, restraunts and other sources, it currently is priced at about 14cents a pound, and is occasionally stolen by diesel owners or grease rustlers.either making biodiesel for their engines, or just running them on used cooking oil, as i do.the grease rustlers try to fill a whole tanker or somthing, to cash it in.  although i have permission to get all my oil free.

[powersavers]

be careful with copper coils, mine got hot eneough to melt/explode. foomp,hot oil vapor cloud,whoomp,bright flash when it all ignited, and oh s..., as liquid oil hit my firetube and blew flames 2 ft out each end,billowing black smoke. this thing was running on a cinderblock, outside my place, looking like a jet afterburner,white,blue and some orange flame and a good bit of thrust, all with no blower. melted some ally cans and pipe, then a few hrs later,the copper tube overheated and blew. i think it was my fault, though, i stuck a piece of steel in to melt that. yea,it melted, a tiny bit, then channelled the heat to the copper coil it was touching,oops. prototype#2 will be steel.