Ofeldt Blueflame Kerosene burner

After about 8 months off and on development trying to burn kerosene, I think I have a pretty good replica of the Ofeldt Blue flame burner. It uses a vaporizer coil around the mixing tube with two Optimus Nova campstove pilots to heat the vaporizer - warm the mixing tube and ignite the burner. Burns blue and hot with kerosene.

Here is a video of firing it up.

[www.youtube.com]

-Ron

Nice job Ron.
Rolly

Yes - a great job. What fun it is messing about with burners!

I like the idea of heating the mixing tubes - that is where, due to the pressure drop of fuel leaving the jet, and mixing with cold air, the stream of fuel can easily condense back to droplets. In a Stanley the fuel, which leaves the jet at 450F or more, can drop way down to under 200 before it gets to the mixing chamber.

Mike

Hey Thanks fellas..

The main issue with kerosene is it is difficult to vaporize, the inverse is true as well, it condenses very easily. In the shaky video that is displayed, there is gas coming out of the nozzle once it warms up and it quickly turns to fog. Then where it comes in proximity of the walls of the heated mixing tube it goes back to gas. Would take lots of experimentation to perfect that (without igniting the fuel, had that issue too with the last mixing tube, this one has another thin piece of tube in between the actual mixing tube and vaporizer to insulate it from the direct heat). It's running really well now and I'm going to leave it as is.

Another point discovered with this type of vaporizer. The same amount of heat is impinged on the vaporizer continuously whether the burner is off or on. According to Ofeldt, when just enough heat is used to vaporize the fuel and no more, scorching the fuel is prevented thus no carbon production. According to them, some of their burners had been in operation for four years and had never had the vaporizer cleaned. We shall see.. I read a lot of these old claims with tongue in cheek. They also claimed Kerosene is 30% hotter than gasoline, modern day charts have it around 10%, not sure where Ofeldt got the other 20% at It is pretty hot though, the Ofeldt boiler in this car holds about 2 gallons of water and it will make steam in about three minutes from cold.

They also claimed that gasoline was getting harder and harder to find and would soon be unavailable! and this was in 1908? Apparently refineries had not set up reliable distribution for gasoline yet.

When I disassemble the car for paint, I am going to draw the burner up. It is very inexpensive to build, made from 1/2" EMT conduit and muffler pipe from the auto parts store. The Optimus Nova pilots are 125 each on Ebay, of which over half of the retail unit assembly/kit is discarded. Might be worth an email to Optimus (in Sweden) to see if a person can purchase just the burner head.

-Ron



Edited 2 time(s). Last edit at 12/17/2014 10:17AM by IronChief.

Ron,
You are going in the right direction, cold mixing tubes definitely do not help. Stanleys never learned.
Dig into the early jet engine post mix vaporizing burners on Google, some good work was done then especially with recirculating hot gas burners.

Investigated this too and was told by the Chevron guys that gasoline was distilled from crude until about 1912, after that it was generally catalytic cracking to increase the yield, totally different molecule. The vaporized gas should not be heated over 450°F or it breaks down and forms carbon.
Jim

In the UK many Stanleys run on 50/50 or some other mix of unleaded and diesel with the idea of achieving a similar result to kerosene, and avoiding the need to buy kerosene away from home. Mostly it works well but because of the huge range of vaporising temperature of the mix there must be much condensation of the diesel fractions within the mixing chamber. I never felt that this was harmful to the combustion in my Model H and obviously any droplets of diesel would evaporate instantly when going through the burner plate - maybe even helping this from getting so hot as to light back underneath. But fog may not burn as well as vapour, certainly when I fired up the burner away from the boiler I could see flashes of yellow flame in the fire clearly due to droplets getting through. This only happened at start up before the burner was fully warmed up and as these flashes occurred, the burner made a yelp of howl. I note your Ofeldt only gave a very slight whistle now and again.

Another reason for the gasolene/diesel mix is the variable and often poor quality of ordinary kerosene. A friend was given the task of making the BRM/Rover gas turbine Le Mans racer work again after many years. He assumed commercial kerosene would work but the results were impossible due to flame outs and other problems. Switching to aviation grade Jet A-1 fuel transformed it. Aviation kerosene has a narrow range at which it boils so that the vaporising heat input can be closely set. Commercial kerosene has a wider range of constituent hydrocarbon chain lengths so boils over a wide spread of temperatures. The gas/diesel mix also boils over a huge range of temperatures but because the gas and the diesel have to be closely specified to work in ic engines the mix is at least consistent and the vaporiser can be adapted to it.

As to carboning up of the vaporiser tube - as long as it is located so as not to get too hot and is of the right length so the last foot or so is not adding too much heat, carboning up does not have to be a problem. Mine was just right and I would say I only cleaned it a couple of times per season and rarely found much crud. I never had to burn the vaporiser out and only fitted a new wire after 7 or 8 thousand miles use. I was always careful to keep the fuel mix to 50/50.

There's no doubt at all, your Ofeldt controlled heat to vaporiser is a good scheme.

Mike



Edited 1 time(s). Last edit at 12/17/2014 04:12PM by Mike Clark.

Mike Clark Wrote:
-------------------------------------------------------

> I note your Ofeldt only gave a very slight whistle
> now and again.

> Mike

I think that is the band brake howling. I've never heard the burner make any noise other than a large rush of air like a turbine.

-Ron

Here are my notes from the burner build for study.

-Ron

Thanks for that Ironchief. The only extra feature would be a flare on the intake - nothing much just turn out the edges on about 0.25 inch radius like a carburettor intake flare. Stops the air molecules from arguing about who goes in first!
I like your upward sloping mixer tubes - why didn't Stanley think of that.

Mike

For whatever it is worth on the jet burn can....the fuel is supplied to a non drip atomizer nozzle at 350+ psi have seen that pressure go upwards of double that on some engines.So that you got that white mist that you showed in the video on your burner.Then the ignitior would fire before you went into a hot start from too rich in the combustion chamber.The J tubes in the early days of aviation did what you where doing preheating your burner.IN the model jet crowd many of the guys had to start on propane then switch jetA...large selling item at this this time, on new model jet engine is they can start on kerosene like the real aircraft can.(fuel flow on like the 25hp jetcat was 8oz/minute or 5.8oz./min on 7.5 hp wren)
To some degree fuel oil burners are working the same way....
At the same time you did a good job of working without electricity.....

Arnold Walker Wrote:
-------------------------------------------------------
> So that you
> got that white mist that you showed in the video
> on your burner.Then the ignitior would fire before
> you went into a hot start from too rich in the
> combustion chamber.
> At the same time you did a good job of working
> without electricity.....

Yes, I rushed the start up. And too, there are two valves on the fuel line going to burner and I forgot and left the one at the burner open (the firing up valve). I opened the first one and it let liquid enter the mixing tube and nothing was really warm yet. And too, it was only 48°F outside. Yes, trying to keep it all non-electric analog, like the White steam car.

Just recieved an original Stanley water level control today to copy. Not sure how well it will work with the Ofeldt boiler and it's small reserve.


Mike Clark Wrote:
----------------------------------------------

> The only extra feature would be a flare on the intake - nothing much just turn out the edges on about 0.25 inch
> radius like a carburettor intake flare.

For sure, it should have that on there.

Thanks, Ron

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