Waste Oil/wood Burner update 1

[Harry Bloomfield]

I have just run a test burn using waste bits of wood.

The 3.5" x 3.5" x 3mm square box section flue enters the gas bottle around the perimeter of the top and enters at an angle of about 7 degree from the vertical. The end of the flue was left square cut, so it leaves a bit of a lip inside the bottle at one side of the flue and flush at its other side - so it forms a bit of a scoop for the gases, if they are made to swirl the right way - anti clockwise.

The air intake is a 3" diameter mild steel pipe, which fits in the top

- in the large hole left by the fitting for the regulator. It hangs down about 2" below the level of the top of the door and sticks out of the top about 15". For now, it is just tack welded in place. The total length of flue is about 3m made entirely from the mild steel box section.

It rises from the bottle at a 7 degree angle to vertical, straightens up to vertical for about a foot, then passes out horizontally through the garage wall, then back to vertical for final 1m. Where it meets the gas bottle, I fitted a short piece of the box section, with a flange to enable it to be removed leaving the main flue in place. On top of the flue I added an upside down V steel bracket and bolted a V shaped bit of alloy sheet on top, to prevent rain coming down the flue.

No matter what was put in it for fuel, it burnt without any visible smoke - all you could see was the heat haze, unless it was over loaded. When over loaded smoke would not only come out of the flue, but also the air in tube. I had to keep all three doors wide open when it first started to heat up, due to the paint burning off the gas bottle, once burned off it was fine. When the fire seat declines, opening the door wide spilled some smoke out, but almost closing it sorted it. I didn't try very hard, but I could not get it glowing hot.

My uninsulated garage (12x24) and workshop (10x16) roofs have been covered on the inside with condensation since the snow/freeze up and it was still dripping quite badly when I first lit the stove. After an hour it had all dried out and the temperature was up to 22 degrees. Outside it was 2.5 degrees. Even the top of the flue outside was too hot to touch.

I did not fit a grate for the test, just set fire to some waste paper and piled a few bits of waste wood on top, in the bottom of the gas bottle. It is all just roughly in place, nothing yet fixed.

So I think I will call that a reasonable success :-)

I'll see if I can't get it working on oil next weekend, and organise some photos - if everyone promises not to laugh at my welding.

[Jules]

Interesting project. Unfortunately I missed the original thread on this and just caught fragments here and there. *If* it's relevant, what have your insurance company had to say about this? They get really jumpy over here about anything burning wood unless it's had all sorts of offical approval stamps on it - and even when it has, not declaring it typically invalidates the policy.

I'm just curious (and maybe it's not relevant here because you're doing it in buildings not covered by any insurance anyway?)

cheers

Jules

[Harry Bloomfield]

Jules brought next idea :

It is not relevant - it is a separate out building and not covered by the insurance.

[The Natural Philosopher]

keep trying..

which sows you are wasting heat, and causing a very dangerous fire hazard.

What? to weld up a box and a pipe, and call it Harold Wilson?

fires are not exactly rocket science.

Anyone can make a fire that runs well.

Running well and safely, and efficiently, is another matter..

I will be crying when you report the loss of your shed.

[The Natural Philosopher]

Let's hope it doesn't set fire to anything that is, then.

[JimK]

sayeth the man with 2 open fires.... :>))

JimK

[Harry Bloomfield]

It happens that The Natural Philosopher formulated :

Flues burning this sort of stuff need to be reasonably hot, to prevent build up. I'm not really looking for a great deal of efficiency.

I think you may find combustion is quite similar to rocket science :-)

Anyone can make a fire.

[Andy Dingley]

When you say the words I'm not allowed to repeat, what size are we talking about?

[Harry Bloomfield]

Andy Dingley explained :

Good question and I don't know the answer it was an old blue rusty one with no markings I could see, but it was a similar sized one to the one on our BBQ - which I will check the Kg of that one in daylight. It measures roughly 12" diameter x 20" tall (excluding the valve). Its the large diameter, but not the tallest you can get hold of.

[The Natural Philosopher]

and absolutely 'to the regs flues' with them.

And frankly, having seen houses burn down, happy to pay the price as well.

Actually we have four fires here, if you count the Aga. 4 flues in two stacks. And thatch. All to the letter and beyond.

[Grimly Curmudgeon]

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Harry Bloomfield saying something like:

13kg, then.

[JimK]

oh absolutely especially with a dried grass roof !

(i was refering to your "wasting heat" comment....:>))

JimK

[Harry Bloomfield]

Harry Bloomfield laid this down on his screen :

the (white) gap where the main flue connects to the short stub of flue exiting the gas bottle - the flange. Neither gas bottle now flue are in their final locations, the gap will close up once they are. The flange is simply 4x strips of steel welded on the inside of the short stub of flue.

The circular air in pipe is just roughly tacked in place, subject to further tests burning oil.