waste oil burner "ozzirt" type. Works well

[mikenash]

Hi guys

I talked about this a wee while ago when I was building/assembling bit

My objective is/was to understand the process so that I could build something that works well & burns cleanly.  So this contraption isn't attractive - it's just a "proof of concept".  Some of the bits, such as the burner bowl, are just tacked in place for convenience, and the whole thing is put together with flanges & 16mm bolts so I could assemble it safely in the paddock by my shed

In the end I only gave it two ten or fifteen minute burns - enough to get an initial handle on the "tuning" so that I can build a "Mark 11"

Objectives:  A controllable process.  A drip-feed (or possibly a cheap peristalitic pump).  No blower (off-grid-friendly).  Clean burn

All I did was watch about 50 videos to get a handle on what worked and then built one with easy options for controlling primary air, a guess at secondary air and a big 40mm tube with a gate valve on the end for adjustable tertiary air

The big hot chamber bit above the heater tube has baffles so the "burn" has to flow around a few things to shed some heat

Specs:

Burn pot is just a bit of 200mm diameter steel tube about 60mm deep with a bottom welded in.  All the random plumbing shit in the front is just me playing with a temp oil feed.  There are two 15mm primary air holes - plus whatever leaks in around the drip feed and where the bowl is just tacked to its mount.  Once it's up and burning I cut the primary air feed back to a single 8mm orifice

Tube and secondary air is just a 400mm-odd length of 100mm pipe with sixteen X 16mm holes in it.  Just a guess.  Seems about right. 

Tertiary air feed at the top of the burn tube/bottom of the hot chamber is a 40mm BSP socket welded in.  I attached about 500mm of threaded pipe with a gate valve on the end just so it was well away from hot bits while adjusting

I have attached a couple pics and links to three very short youtube vids

https://www.youtube.com/watch?v=ImcuhlNG9sU

See very short burn video

https://studio.youtube.com/video/5TO1d7GITzk/edit

and very very short flue - clean heat haze video

https://studio.youtube.com/video/H9qSTerqfEk/edit

And very quick look down into fire

https://www.youtube.com/watch?v=ImcuhlNG9sU

https://www.youtube.com/watch?v=ImcuhlNG9sU

Performance:  I have hard data lol

I put 1.8 litres of cold water (13 degrees) into the copper kettle which has a flat 150mm diameter bottom, and put it onto the flat 12mm plate top of the burn chamber before lighting the burner from dead cold.  Ambient air temp probably same as the water at 13 degrees?

The little temp oil tank takes 1.17 litres of oil.  In this case waste AWS 32/46 hydraulic oil

It used 900ml of oil to raise the water to a rolling boil that was lifting the lid off the kettle and when I lifted it off the thermometer says 84 degrees

So:  900ml of oil burnt from stone cold to raise 1.8 litres of water 71 degrees.  Took about 5/ten mins?  I'd guess it'd take a third of that if you put the kettle on when the top plate was hot?

My cheap point-and-squirt thermometer only goes to 380 degrees centigrade and, after about 5 mins burning, everything was just maxing it out.  I guess the red heater tube is about 450+ celcius?

There's good stuff to learn here

Conclusion?  It looks do-able to have a smoke-free, clean-exhaust burn

[veggie]

mikenash,

That's quite interesting.
Did you take any pictures of the internal burn pot arrangement.?
Is there a smaller pot inside which contains the oil while it burns? or does the oil drip onto the floor off the main lower housing.

Consider a tangential inlet for the air in order to make a swirl in the combustion area.

Looking forward to following the development of the " MARK ll"  (thumbs up !)

veggie

[mikenash]

G'day Veggie

I reckon the little bowl at the bottom is a bit neither here-nor-there.  You see so many designs and if the air flow is good - they seem to work OK-ish

That said I'd like to use a stainless bowl for the next one for a variety of reasons:  should glow red, might knock burnt residue out easily? . . .

With my current one, beneath where the oil drips in there's about 100mm of 20X20 angle, Vee downwards, like a little trough, and sloping slightly down, directing the oil flow to the centre.  I have no way of knowing if it makes a difference.  It certainly works OK lol

The reason I think the burn bowl doesn't matter much is that the fire is tune-able, so I figure the initial burn is OK.  Depending on how much air is going into the bottom pot, you can have the smoke from a busy, rolling, "coaling" black to almost clear - then with the addition of tertiary air it will burn dead clear (see the wee vid with the gum tress?)

And it only has about 1400mm of flue.  Would probably respond better with a long flue?   So I reckon the basics are good

Cheers

[mikenash]

Veggie - I should have said, too:  the reason the whole thing is built as it is - is that it's all stuff lying around the workshop.  Total cost to me was $0.00.  It was just a proof-of-concept

Mk11 will have design requirements I guess.  But I'll try to keep costs low lol

[mikenash]

OK Veggie

See rough schematic attached?

I have most of the bits for Mk11 lying around the workshop and hope to go up to site this weekend with the angle grinder & cutting discs to take re-useable bits off of Mk1 and consign the rest to scrap

I guess I’ll build/assemble Mk11 out in the paddock in the same place so I can burn/tinker/tune . . .

An ideal outcome would be something that started up cleanly & fast and didn’t smoke at all apart from up the chimney.  If I can achieve that, and get it to burn OK on the “clean” waste oil of which I have potentially several tonnes – then I’d put one in my shed

It’s not the sort of thing you would leave burning un-attended.  Initially, at least, (I would think) you would want the major safety feature to be an oil reservoir that was quite a bit smaller than the burn bowl so that if something went wrong in the valving area . . .

Basic features of Mk11 might be:

A main body ex a 550mm length of 400mm diameter heavy-wall pipe (selected because I have it here in the yard), with a vertical baffle in the middle and a removable top “element” that would allow you to tinker with the baffle, or to make steel bits to hang down and pick up extra heat or whatever . . .

(In the past, in other applications, I have made removable top-plates like that from good-quality flat cast-iron because it doesn’t buckle or warp.  I have a bit or two here somewhere)

It would be nice if I could achieve a vaguely “oval” top plate, dead-flat, and around maybe 650mm X 400mm.  If that had, perhaps a “hot” centre and possibly a couple of cooler extremities – that would be great for sitting the frying-pan or kettle or whatever on

At the moment my thinking is to re-use the burn pot and burner/air tube off Mk1 initially.  I don’t know if a design like this will work OK with a bend at the top of its burn tube or not – I guess we’ll see

I’d hope to get onto building bits as I have time over the next couple of months – workshop availability permitting

Cheers

[veggie]

Interesting design !
The secondary burn chamber should add some great efficiencies and heat capture.
I assume the burn pot is removable for ash cleaning?

[mikenash]

Okey-dokey

I realise this isn't a subject in which there's a lot of interest - so my apologies to anyone who feels his time is wasted by it.  But it's only really my time wasted

There are lots of simple draft-type burners around and they're capable of immense heat, limited only by one's personal courage, as far as I can see

I must have watched 50 or 100 YouTube vids of burners ranging from awful to unbelievably efficient-but-complex.  So a while back I posted some pics and a short video or two of my iteration of an "Ozzirt" type drip-feed burner - it was just proof-of-concept, really, but I was encouraged by the fact it would respond to "tuning" the air intake at bottom, midpoint and top (primary, secondary & tertiary burns - if you like) and the fact that was repeatable.  Plus it was easy to have it burn "clean" - at least in terms of exhaust output

So I'm 2/3 of the way of building Mk11 as mentioned a couple of weeks ago.  See pics attached?

It's still rough, still proof-of-concept.  I wanted to see if the Ozzirt drip-feed design would burn through a big chamber and around a baffle - to capture and dissipate a chunk of the heat - and also if it would do that with a "cook-top" top section which, in an ideal world, would incorporate sections that were "hot", "bloody hot" and "simmer"

So here's some ugly cut-and-shut construction.  It's a hunk of 300mm (12-inch nominal bore) pipe with a 12mm (1/2 inch) wall - should accumulate a bit of heat with a bit of luck) and the top is made out of some scraps of 12mm flat too

There's a base (not shown cos I forgot) which incorporates a stand etc . . ,

The intake/burner bowl/burner tube is a re-use of the one in the previous post - but I welded a section of 100mm BSPT male thread onto it and welded a 100mm BSP socket onto the bottom of the intake part of the big "stove" chamber - so the burner tube and air intakes assembly hangs off the elbow shown and is removable to play with as long as the thread lasts (not long I suspect)

At the exhaust end of the stove chamber thingie there's a 125mm flange welded in place two-hole-square, so I can attach whatever I like to it, flue-wise, simply by building it on the end of a suitable flange with two-holes-square orientation

Like any piece of amateur cut-and-shut, it's ugly - although it'll clean up with some weld-grinding.  Basically I tacked stuff together, heated it with the gas to bash into shape in the join areas and filled the gaps with weld,  It'll work well-enough to prove/disprove the concept

My aim is to have a "stove-type" burner which is safe-enough to put in my shed and which will radiate a chunk of heat and which has a "cook top" function.  So this is a first step towards that.  I wouldn't anticipate building anything that one would leave burning unattended

The base (not shown cos I forgot to photograph) incorporates a steel "tank" for want of a better word, made from 8mm plate, and with 40mm BSP sockets at each side - because I'd like to see if there's a safe way to "pre-heat" the heavy oil of which i have several tonnes available

So there we are.  Excuse long-windedness