Jump to content
Glort

Veg oil home heater.

Recommended Posts

Lying in bed last night I got a brainwave. It happens every 10-20 years.

I built a an oil burner a while back that works on draught alone. Burns pretty clean and puts out awesome heat though most of it of course is in the flue gasses rather than radiant.

The thing is an old casserole type pot I cut a large hole in the top and sat an old fire extinguisher on that I cut the top and bottom out of and put a load of holes in the sides. On top of that I put a length of 4" Pipe. Around the edges of the lid of the pot I put 4 1" holes.

The fire burns in the pot and gets the primary air through the 1" holes then goes into the secondary chamber where the air mixes pulled in by the draft of the chimney. It could use more holes in the Secondary chamber to burn perfectly clean but that would also dilute the flue gas temp and rich is hot... Just like a Diesel engine! :)

So what I did today is get some 20L oil tins from a load I picked up on the weekend and fitted the 4" pipe right through the middle. With all the delicate skill and craftsmanship an unskilled person can muster with a wood chisel, a hammer and a pair of pliers, I cut a nice snug fitting hole to the top and bottom drums and the ends out of the middle one.

On the bottom burner I fitted a squirrel cage Blower and on the top, I impressed myself by cutting a hole in a star design with the metal sections coming out so I had somewhere to tape the duct on.

The blower wasn't quite strong enough to force the air through so I got an 8" in-line ventilator fan and put that on to act as a booster and put some more duct on that to take it inside through the cat flap.

The blower merely blows air on the flue pipe which normally glows red for about the first 2 feet and the resulting warm air is blown in the house.

The setup looks as redneck as Imaginable but stuff me if it's not about 30o in here and I have the burner running at about 1/3 power.

It's using about 2L of oil an hour which is high because it's real inefficient atm but I can fix that. I'll add another 2-3 tins tomorrow on the flue pipe which is still uncovered and bloody hot. I think this will allow the burner to be throttled back some more and the same or better heat generated.

1L/ hr of oil generates about 30Kw so even with poor efficiency, that should keep the place nice and cosy.

I have to say I'm a bit amazed at how well this works. Sure it's about 20% efficient ( 80% INefficient) ATM but it's a stack of oil drums with a stove pipe in the middle and a fan blowing air on it. The surface area to the cold outside air is far greater than the area exposed on the hot side. I have some insulation that will fix that. The extra drums will help as well.

I'll take some pics tomorrow for a laugh and post them up.

The thing is, this Pile of scrap could run on any waste oil you can get your hands on.... engine oil, tranny oil, Veg, hydraulic or even animal fat. All you would have to do is start the thing with some liquid oil, sit your drum of fat close by and it would melt the stuff as it burnt.

The blowers I am using are about 150W and the amount of heat I could generate with this thing would melt the snow off the roof of a place if required.

What it has opened my eyes to is how efficient something like this could be if a Dollar was actually spent on it. This thing will last me this winter then when I'm in new digs next winter I'll do something up properly.

Perhaps the biggest achievement with this thing is I'm still in the house. The mrs came home and saw this " construction" sitting on her beloved back Verandah and wanted to know why the hell I had brought my chit onto her veranda and it better not be there tomorrow.

She seems very happy to have it there right now and be sitting round watching TV in a T shirt instead of a jumper.

We have air but I think shes enjoying having this thing turned right up without having to worry about what it's doing to the power bill.

So far the only comment is can I put a duct in the wall so the animals can get in and out the cat flap?

WINNER!

Quite satisfying

Share this post


Link to post
Share on other sites

Sorry, Didn't get to it today.

I'll post some up tomorrow.

Be warned, it ain't Pretty! :P

I did put 2 extra drums on the stack which has made a big difference. I reckoned I gained about 20-30o on the output air temp burning at the same rate.

I reckon the way to put some efficiency in this thing would be to use something like an exhaust collector with a 4" pipe going into 4x 2" pipes. You would spread these out slightly so there was plenty of room for air circulation and better surface area. You would also slow the gas flow from the burner giving more time for the heat to be transferred.

That would cost a lot more of course that the bit of pipe surrounded by tins though. :)

Share this post


Link to post
Share on other sites

Some pics of the contraption.

Now while you are laughing, Remember this was built entirely from crap around the house save for 1 $4 clamp!

IMG_0266.jpg

IMG_0269.jpg

IMG_0272.jpg

As can be seen, it's really nothing more than a Pipe running through a bunch of tins that are used to catch the air being blown into them. Amazingly it works and works pretty well.

I started with 3 tins but then noticed how hot the flue above them still was so added the top 2. It made quite a difference to the temp of the output air with the burner running at the same heat. The bottom ones work on pressure from the blower, the top 2 have air drawn through them by another more powerful fan I have boosting the bottom blower. I was going to fit another blower on the top but I have to see if I have a run capacitor for the motor.

The Burner is non powered and relys only on draft to pull air into it which heats the oil and burns it. The Primary air comes in the holes in the top of the pot lid and the secondary air where the real heat happens in in the chamber with the V's cut it it. The burner itself is generating about 20-25Kw of heat energy.

There are 4 holes in the lid of the pot. I put bolts in them to block them off to throttle the thing.

The next one I do I'll use a bit of 2" Pipe and make up a simple butterfly valve for it so the thing can be throttled a little more practicably. This would also allow me to fit a stepper motor and control the thing remotely. I was also thinking of using a remote resviour with a float and needle and seat like a car carby for fuel level control. I would pipe it to the side of the burner so as the level of oil in the burner dropped, so it would in the cold float chamber and the thing would keep the fuel level constant.

Atm I just pour the oil in the burner with an old kettle. about 2L lasts for about 90 min with the thing set at half power where I am running it. I haven't measured the air output temp, I'm guessing its around 50o but I have a couple of air bleeds past the hot areas to keep the output temp down. Don't want to melt the duct tape holding it all together! :P

I'd like to get an old gas water heater and take the burner assembly out and put one of these in it's place. The work exactly the same as this heater. A burner on the bottom and a flue right through the middle of the tank. I could have free hot water or pipe it round the house and pull the heat out through a radiator(s).

I'll leave this bogan looking thing for this winter as we don't have that long to go now and I'll build something a little more reasonable and efficient for next year.

Better heat exchanger, remote burner control, auto fuel level and shutoff and I'll have a very cheap to build and free to run burner that could be scaled to pump out as much free heat as required. Also wouldn't be hard to run a branch pipe through another larger pipe that was sealed and use that to heat water at the same time.

Anyway, it's freezing here this afternoon, I'm going out to fire the thing up and have the whole house and a nice 25o for the night and not have it cost me a cent! :D

Share this post


Link to post
Share on other sites

Cool.. Very cool.. So. Were have you sourced the fans from? They are very neat and compact..

I like the idea of a remote butterfly valve? Are you meaning remote but still change by hand or control from a dial inside the house remote??

And how do you like your? Oxy? Read heads lighting cube?? Petrol?

And were ow were did you score the inline fan and ducting from??? Guessing that is the most expensive part of it all..???

Edited by BigGQWesty

Share this post


Link to post
Share on other sites

Blowers were a find on evilbay. Bought one and because I was telling the guy what I had them in mind for ( another oil burner project) he gave me another for nothing as his late father also was into to building waste oil burners. got them for $16. I thnk the guy has more, Might go back and pick up some more.

For the butterfly valve I was thinking remote from inside the house. If it had a stepper motor attached to the shaft you could just turn a dial inside and it would open the thing to whatever amount. With the fuel level control, you could put a solenoid on it and with the air and fuel shut off you could shut the thing down remotely as well.

Lighting is done normally by rolling up some newspaper in tight balls and sticking it in the top of the burner with a bit of oil and lighting it. Previously the flue hasn't had a heap of tins attached so what I'm going to do is knock up a stand to sit the tins on then get an old car jack and put the pot on that so I can raise and lower the pot for cleaning and lighting.

ATM I'm using a little petrol, as apprehensive as even I am about that, but given I light it real quick and its cool so I don't allow any vapor buildup, it's lighting with just a puff and taking off well. It's not the method I reccomend even to myself!

Once I put the jack underneath, I'll go back to the balled up newspaper. It takes longer to get going as there is less heat to draw the air in. There are some things I will go against the grain on all day and don't give a rats but petrol I have a LOT of respect for and try to avoid using it like this where possible. Kero would be the Ideal starting fluid or the fire lighters you mentioned.

After a while the burner does get some carbon buildup but I think that is a result of the poor primary burner design and I can improve that on the next one. The burner was a " I wonder??" effort while eyeing off the old pot and thinking about the way I thought an old style " Smudge pot" burner worked. Pretty happy with that effort but it too can be improved.

The inline fan a mate gave me years ago as a hair blower for my glamour Photography work. Awesome thing, could blow their hair straight back and level from 8Ft away.

The one I have is the Rolls Royce version worth a fortune. They are made to be put in buildings and run 24/7 for 10 years non stop. I think my mate said it was worth about $1200 10 years ago. You can get a lot cheaper though and I have been doing the menal arithmetic on using a car radiator fan in a plastic drum and attaching the ducting to that. I was also thinking about mounting a radiator fan to the side of the drums and using it to pressurise the air through. I know there is a difference in fans that will do volume and those that will do pressure, even in a duct. I'll have to test the car fans.

The duct is just std 8" aircon flexible duct. You can get that at any air con wholesalers and you could get the spigots and ducts for it as well. All that stuff is cheap as chips. The duct I have I pulled out of a house when I was helping my mate put in a ducted system. The people had extended the house and wanted a bigger unit so I salvaged some of the old, not so old at all ducting.

You could also see the air con place about the inlines. You can get cheaper ones that would be more than up to this job.

So now you can start looking for a source of used engine or tranny oil Westy! :)

BTW Westy,

I'm also working on another contraption that will "crack" or Pyrolise Used engine oil, tranny fluid, plastic bags and Bottles etc and turn it into Diesel.

So far I have got it a bit further up the fraction chain, something between diesel and petrol. I know the trick to getting one or the other, just have to adjust the design to get what I want.

I'll post up info when I have some repeatable results and finalise the reactor design.

Edited by Glort

Share this post


Link to post
Share on other sites

Well you have made my next project.. Going to make a shed heater to start.

That's what I was originally going to use the burner and the flue for.

For a shed heater, I wouldn't bother with the tins to enclose it. You could have an old fan blowing across the Flue to take the heat off. In a shed you could have the burner inside. I didn't want to be cutting flue ducts in the roof or walls of the house.

As long as it was away from anything flameable, in a shed it would be fine. All you need to do is duct the flue out through a wall or roof. Easier through the wall.

I would probably put a bit of Corrougated iron around the burner or some metal to controll the radiated heat. I have an old washing machine I'm going to fix or wreck and I thought with a door cut in the cabinet, it would make a nice, neat burner enclosure,

All you need to do is duct the flue out through a wall or roof. Easier through the wall. You don't want to be breathing the fumes and the bits of carbon black that will come out on occasion.

If you did something like an enclosure with a cabinet, What would also help efficiency would be to put a duct in the bottom to the outside air.

One inefficiency with fire places is when the air goes through the fire and up the flue, it creates a negative pressure in the room and that causes cold outside air to be sucked in under doors, through windows and in your shed, every nook and cranny. If you have a duct from the outside providing the air for the fire, it's not sucking cold air in towards the fire and pulling the hot air nearest the fire out.

While I know you don't need a fire to be super efficient. it's best to make them as efficient as you can because they are still going to be low and you don't want to be spending all day putting more fuel in the things or constantly collecting it.

To get more heat out of the thing, I'd also do a long run if practical Horizontally with the flue. Blow a fan along that and you'll get a lot of heat out of it.

All you would need to do is put some rise on it once it goes out to make sure there is plenty of Draft.

Share this post


Link to post
Share on other sites

Well I'm going to try using 9kg gas bottle for the base, and hopefully a mate of mine can grab some 4" s/s for me today..

Also going to try make a butterfly valve.

Might try an auto feeder from a 20L drum gravity fed.

Share this post


Link to post
Share on other sites

Well the 9kg bottles are in the shed.. 60L of oil being grabbed now.. Hopefully the 4" s/s flu is being grabbed now.

And good idea with the diesel Bog. I'm going to try a fire lighter. They burn for 15 mins so that should be long enough..

Edited by BigGQWesty

Share this post


Link to post
Share on other sites

Nice Weld!

Where does the pipe go inside the bottle?

It will need to be aimed down at the pool of oil so the flame goes back on itself and heats the surface of the oil to vaporise it.

I think if it's straight in the side, the air will mainly be drawn up the flue instead of towards the oil to support combustion. You might also want to distance the valve from the bottle a bit because I think it's going to get awfully hot where it is.

How are you going to set up the secondary air inlet?

Share this post


Link to post
Share on other sites

Bugga Glort.. Lol. It's just a flush mount on the side. Nothing inside. Owell I'll give it a crack. Can always cut it off for mk2...

But I was intending on making the flu the secondary burn. I was going to ask you about that. How many holes, what angle is the flow (up or down) and how big have you made the holes.

I'm going to slot my flue in a pattern and the press in (above or below the cut depending on your answer to flow direction) the pipe to make the hole..

My main concern is the chamber. I think it may be to tall and might need a chop. But well see..

Share this post


Link to post
Share on other sites

Give it a go as is. Nothing to loose that's for sure. If the flue is long enough you may get enough draw to make it work.

If you can get hold of a blower or a reversed vac to attach to the valve air inlet, that burner could work to put out some major heat. Forced air ups the Ante by magnitudes.

If it dosen't work, just cut the bottle in half, add in the right angled bit of pipe inside and stitch it back up.

As for the secondary chamber, I don't think there is a formula for the holes. You can add a lot though and when the thing has a section with more holes than a swiss cheese, it seems about right.

I drilled some holes in mine which were pathetically inadequate. the thing smoked like that truck in the vid you linked. I just kept adding holes till the thing got to a reasonably clean output. It could do with some more holes but it's burning with a light haze now which quickly dissapates so good enough.

One thing I would like to try is to use some mesh ( expanded I think they call it) for the secondary chamber. This Would be similar to the flame holder in a gas turbine. I know it's more air than metal but I think it would be the go. the potential problem I see is having too long a section and killing the draft in the primary chamber but I think " tuning " it would be as simple as starting with about 200mm or so and cutting it down a little at a time till the thing ran the way you want. maybe with this you'd only end up with 5 cm of mesh but I'm sure it would work and work well.

For the holes in the flue you have, If you can notch them, I'd be doing them at an angle to get some swirl and better mixing with the air and vapor. For a man with everything at his disposal for the job, I'd also be cutting some slots into the pipe here and there and inserting a bit of flat bar again at an angle and having that go through the tube from inside to out. this will add swirl into the flue and break up the air stream so you don't just get cool gasses on the outside and hot ones on the inside.

I did my holes in a V shape and tried to get some angle and for the second lot I pushed the tabs in. The thought was this would create a negative pressure above the tabs as the flame came up from the primary chamber and this would help draw the air in. I also thought the turbulance created behind them would aid in the mixing of the gasses.

It seems my idea was on the money. I noticed that on teh first tabs I pulled out, there gets to be a lot of carbon build up around the holes. On the ones which I later added with the above idea, the chamber stays perfectly clean. Like as in when the thing is out you can wipe your finger there and there is no black.

Also if you welded a bunch of small bits of metal to the outside of the flue, it would do a lot I think to increase the surface area and heat the air.

Sure wish I had a metal shop and the gear to play with this stuff. I have been facinated with it for a long time and there are so many things I'd like to try but have neither the skills or the equipment to put them into practice.

I might try and finish my mega heater this week. It's a forced air burner that -can- kick out 400KW ( but I'll throttle back to an idle) in a 44 with a car radiator sitting over the top to catch the heat.

The water is circulated with a pump to another radiator and a fan attached to pull the heat out and into the house.

I think this design would be a lot more efficent and the amount of heat potential would be just stupid.

You should knock one of these up if your factory gets a bit cold in winter.

It wouldn't be cold for long I can gaurantee you that! :D

Then again, you wouldn't need the radiators in a factory. Just do a long run of flue horozontaly with a fan or several blowing on it before sending the gasses up and you'd get a lot of heat out that way. With 400 kw coming out of the thing, you'd probably glow the first 6 feet of pipe bright red even with teh fan on it.

Pulling 40L of oil an hour, your company would never have to have it taken away again. Save it up all year round in IBC's to use in winter. :)

Share this post


Link to post
Share on other sites

Well mk1 is a fail.. 2L of petty down and the thing won't stay lit.. Even with petrol...

Either one of 2 things are happening..

1- not enough air.. I have a 1' ball valve on the front, and 2 13mm holes in the rear..

2- could be the secondary..

post-299-134406254596_thumb.jpg

I can see the flames burning at the top of the chamber, but nothing going past.

Ideas?

Share this post


Link to post
Share on other sites

Umm, You have the notches the wrong way mate.

the way you have done them is so neat and should be so effective but you have them going the wrong direction I believe.

You should have them Upside down to what they are now.

As it is, as the flame comes up, the protrusion of the metal wants to take the flame to the outside of the flue, not the air to the inside.

You could just cut that section off, turn it round and stitch it back on again. Regardless of anything else, this would be a lot better.

That said, I'm not sure this is your problem all together. It's certainly not helping IMHO but the fix may not be enough to get things working.

I think the air needs to come down onto the oil rather than just entering from the side. You're kind of doubling up now. The air through the valve and the holes in the top of the tank are supposed to do the same thing.

I think the holes in the top are too high above the fuel, the air is probably coming in the holes and for the most part going straight up the flue.

I'd try cutting the tank in half, or 2/3rds down, put a plate on the top and just bore some holes like I have. I think the air needs to be close to the fuel.

I haven't done much testing on this mind you, I cobbled mine together, lit the thing and it worked. I just added some more holes to get the thing to burn a bit faster and harder and that was it. When i run it though I do see the air sucking the flame back to the oil so i'm guessing that's how it works.

it's not the whole amount of oil that it at vapor point because I can pour in 2L of cold oil to top it up and it barely makes a difference.

To me the back burning is a sign of not enough draft but I'm not sure why. the Flue you have is plenty long enough, it may be the fact the petrol is an aromatic ( so to speak) and as it gets hot it releases more flameable vapor than can be burnt easily with the available airflow.

I think you need a shallower burning chamber and to turn those notches round so the air is drawn in, not the flame pulled out.

From there you might get away with the side entry air but I would put a 90o on it and face it down. You could then block the holes in the top of the cylinder and see how it goes. For a test you could just drop some bolts in like I do and go from there with how that works out.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×