The Steamboating Forum

Here is a simple lifting steam atomizing burner I made for our 40' steamboat "Persistance".
It was made with simple off the shelf plumbing fittings. I chose stainless steel for a long life in the firebox while burning other fuels or running the other burner (Williams burner... For now). This burner can be made a lifting burner, meaning it creates a low pressure area near the tip which allows atmospheric pressure pushing on the fuel in the tank to push or 'lift' the fuel up several feet to the burner tip. No fuel pump needed.

We burn WMO (ancient vegetable oil and dinosaur juice that has been run through an IC engine), but it can be used with any flammable liquid.

The only tools needed are a file (or grinder/sander), wrenches to assemble, and a tap the same size as the small plumbing, in this case 1/8" NTP.

The barrel can be any length one chooses, but in this case I decided on shortest possible in case we run superheated steam to the burner which would mean the fuel could be exposed to much higher temps that could possibly cause it to coke in the barrel long enough to get up to temp.

This burner will burn over 5 gallons/hr with gravity feed, but can be dialed back to much less (as little as 1gal/hr). One could replicate it with even smaller pipe fittings if one chose to do so.

Parts list:

TWO 1/8" NTP x 3" nipple
ONE 1/8" NTP x 4" nipple
ONE 1/8" NTP street elbow
ONE 1/8" NTP four-way female cross
TWO 1/8" NTP plugs
TWO 1/8" NTP to 3/8" NTP bushings
ONE 3/8" NTP to 1/4" NTP bell reducer
ONE 3/8" NTP close nipple
ONE 3/8" NTP female tee
Tools and additional parts:

Pipe wrenches (adjustable hammers)
1/8" NTP tap
Vise
Graphite based high temp thread sealant.

Assembly:

Main body:
Assemble and tighten 3/8" bell reducer, close nipple, tee, bushing, 1/8" elbow, and 1/8"x4" nipple as shown with thread sealant on all connecting threads.
Fuel tube:
Tap remaining 3/8"x1/8" bushing from inside side with 1/8" tap and insert one end of 1/8" x 3" nipple. Sand threads down on other end of nipple at a shallow bevel similar to angle of thread taper. Thread into main body as shown. Some fitting, sanding, and trial and error of the end of 1/8" nipple in final assembly will be required to ensure pipe is centered in bell reducer and tip is sufficiently recessed to provide enough low pressure for fuel to 'lift'.

Fuel line:
Thread remaining 1/8"x3" nipple into 3/8"x1/8" fuel tube bushing. Attach four-way cross with plugs as shown and one plug facing down. Use teflon tape on the plugs as they won't be experiencing high heat and they will be removed occasionally. The bottom plug will act as a sediment trap, hopefully reducing sediment from getting into fuel tube and clogging the burner. The other plug can be removed to allow the fuel tube to be rodded and brushed out.

Plumbing:
Fuel enters the central tube with steam entering through the tube at the elbow. This provides an annular ring of steam to break up and atomize the liquid fuel. This arrangement is much much quieter than the central steam jet of burners like the Williams design and others. We've also experienced a significant reduction in amount of water consumed due to better atomization at lower steam flows over centre-jet style burners.

The two outer exposed 1/8" nipples really can be any length the owner likes/needs for their application. It is recommended needle valves be used on the steam and fuel sides for fine adjustment with ball valves upstream for quick shutoff and repeatability of adjustment.

Operation:
This burner is much quieter than most steam atomizing burner in both the hiss of the steam and the roar of the fire. If you're used to partially regulating your fire by ear, this will take some new learning. Make sure you have adequate open flame near the burner tip, but not occluding the jet in any way. First open the steam a few turns to get a good jet going and wait until the water gets pushed out of the line. After the steam line is clear of water and the key is steady, slowly open the fuel until you get a steady fire and roar. You can then back down the steam until just before you see a change in the fire. You are looking for a fire that is orange to slightly yellowish in colour and only slightly opaque (you should still be able to see most of the features in your firebox clearly). This condition should provide a smokeless stack or a very light haze. You only want just enough steam to atomize the amount of fuel you're requiring to burn. Any more is just water wasted up the stack. Significant adjustments to the amount of fuel being burned should be done in concert with adjustments to the steam. Too much steam can blow your fire out, too little won't sufficiently atomize the fuel and will create a smoke screen or put the fire out.

Remember to always have an adequately sized ABC extinguisher onboard and close at hand, do not try to light off the hot iron or bricks in the firebox (have open flame), and if it flames out and you're experiencing white smoke shut off the burner immediately and open the stack blower full blast to evacuate those explosive vapours before they ignite with a bang. Be mindful of getting unburnt fuel into the ash pit (if it does catch fire will there be enough heat exposure outside the boiler to damage things?), and be mindful of unburnt fuel in the bilge.

I hope you find this helpful and you have success with your burner.

Happy steaming!

Fuel tube: Down the gullet:

I really love the design. Boiling free stuff is a neat idea. Here in the land of poets and inventors, getting free frying oil or engine oil is getting harder and harder, as folks get money for recycling it (which is good for the economy/people and environment. But not for my secret plans )
Btw I like the solution with the plumbing. It's simple, comprehensive and easy to fix.

Do you blow the fuel onto burning wood? It looks like briquets or firewood is inside the burning chamber.

Thanks.

Most of what you see to the left are sections of old road grader tire chain. The main focus of the jet is at a 1/2" thick section of 6" steel pipe cut lengthwise. The steel chunks are in there to act as sacrificial targets to make the fire brick last longer and to glow red hot to help with making sure there's something in there to help keep combustion going. Normally we keep a chunk of burning wood just below the tip of the burner to ensure it always has a pilot light.

Hi Folks

I am most interested by the design but I need to show my ignorance to fully understand it. I was expecting to see a small (say) 1-2mm nozzle hole at the firing end similar to the old Primus stoves. However, it looks as if the nozzle is the whole of the diameter of the bell reducer. Is that correct?

It was good to see your explanations of operations and warnings of what might go wrong.

Regards

Pete

Hi Pete,

Yes the whole nozzle is the 1/4" NTP outlet of the bell reducer. The tip of the 1/8"NTP nipple is recessed in the hole about 1/4-3/8". Steam comes in around the annular gap and the fuel enters in the centre. They mix and voila! Fuel blown to atoms haha.

I have a photo of the jet I'm trying to dig up.
Stay tuned steam fans

Looks nice Wes.

Your nozzle is probably much less likely to clog than the chinese or the Delavan siphon nozzles because the gap appears to be more.

I haven't had a clog on kerosene yet, but I'm expecting it.

My problem so far has been it's just too darn powerful at higher boiler pressures and it is blowing itself out, too much futzing around with the needle valve. I'm waiting for winter to pass, I have this steam pressure regulator I'm going to try out as soon as there is no more freezing in Ohio.

-CB

A steam pressure regulator is essential for steam atomizing burners, as otherwise you get a positive feedback loop. This is especially true for self-lifting burners that automatically increase fuel flow as steam pressure to the burner rises.

These are not difficult to construct by modifying a existing gas pressure regulator with a reach rod to lift a stainless ball in a suitable tee fitting.

- Bart

barts wrote: ↑Tue Mar 02, 2021 12:27 amA steam pressure regulator is essential for steam atomizing burners, as otherwise you get a positive feedback loop.

I tested my new atomizing bus for two nozzles yesterday.
This bus accepts propane for atomizing before there is steam.
Once there was steam the new regulator was set to 35psi and the nozzles restarted on steam.
It was a much more stable arrangement with the regulator, with two nozzles I seem to have more BTUs available then necessary.

-CB

Yes, this scheme works pretty well; I've had a similar arrangement on Otter for many years. From personal experience - make sure that the propane cannot flow backwards into the steam plumbing, and vice versa. Use good leak tight checks for that service. Sooner or later you'll make a mistake, and you want to make sure that the result of the mistake is that the fire goes out.

- Bart