Steam Atomizing Burner

For technical tips, questions etc. on all subjects except Engines and Boilers.
Post Reply
User avatar
TahoeSteam
Full Steam Ahead
Full Steam Ahead
Posts: 648
Joined: Fri Mar 07, 2014 5:38 am
Boat Name: Wayward Belle
Location: South Lake Tahoe, CA, USA
Contact:

Steam Atomizing Burner

Post by TahoeSteam » Sun Feb 14, 2021 3:10 am

Here is a simple lifting steam atomizing burner I made for our 40' steamboat "Persistance".
PXL_20210211_184631752.jpg
PXL_20210211_184631752.jpg (178.48 KiB) Viewed 484 times
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
PXL_20210211_184922764.jpg
PXL_20210211_184922764.jpg (117.58 KiB) Viewed 484 times
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.
PXL_20210213_002511460.jpg
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!
Attachments
PXL_20210211_184631752.jpg
PXL_20210211_184631752.jpg (178.48 KiB) Viewed 485 times
~Wesley Harcourt~
Check out the steamboat and steamSHIP videos on my YouTube page: https://www.youtube.com/c/wesleyharcourtsteamandmore
User avatar
TahoeSteam
Full Steam Ahead
Full Steam Ahead
Posts: 648
Joined: Fri Mar 07, 2014 5:38 am
Boat Name: Wayward Belle
Location: South Lake Tahoe, CA, USA
Contact:

Re: Steam Atomizing Burner

Post by TahoeSteam » Sun Feb 14, 2021 3:30 am

Fuel tube:
PXL_20210213_010633175.jpg
Down the gullet:
PXL_20210213_011749265.jpg
PXL_20210213_011749265.jpg (89.06 KiB) Viewed 478 times
PXL_20210214_213538724.jpg
~Wesley Harcourt~
Check out the steamboat and steamSHIP videos on my YouTube page: https://www.youtube.com/c/wesleyharcourtsteamandmore
Steam Captain
Full Steam Ahead
Full Steam Ahead
Posts: 135
Joined: Mon Oct 26, 2015 2:32 pm
Boat Name: No Boat Yet

Re: Steam Atomizing Burner

Post by Steam Captain » Tue Feb 16, 2021 12:59 pm

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 :D )
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.
User avatar
TahoeSteam
Full Steam Ahead
Full Steam Ahead
Posts: 648
Joined: Fri Mar 07, 2014 5:38 am
Boat Name: Wayward Belle
Location: South Lake Tahoe, CA, USA
Contact:

Re: Steam Atomizing Burner

Post by TahoeSteam » Wed Feb 17, 2021 3:39 am

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.
~Wesley Harcourt~
Check out the steamboat and steamSHIP videos on my YouTube page: https://www.youtube.com/c/wesleyharcourtsteamandmore
User avatar
PeteThePen1
Full Steam Ahead
Full Steam Ahead
Posts: 438
Joined: Thu Nov 19, 2009 11:53 pm
Boat Name: Frances Ann
Location: Cheshire, UK
Contact:

Re: Steam Atomizing Burner

Post by PeteThePen1 » Wed Feb 17, 2021 12:08 pm

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
User avatar
TahoeSteam
Full Steam Ahead
Full Steam Ahead
Posts: 648
Joined: Fri Mar 07, 2014 5:38 am
Boat Name: Wayward Belle
Location: South Lake Tahoe, CA, USA
Contact:

Re: Steam Atomizing Burner

Post by TahoeSteam » Wed Feb 17, 2021 5:09 pm

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
~Wesley Harcourt~
Check out the steamboat and steamSHIP videos on my YouTube page: https://www.youtube.com/c/wesleyharcourtsteamandmore
User avatar
cyberbadger
Full Steam Ahead
Full Steam Ahead
Posts: 987
Joined: Thu Nov 07, 2013 9:16 pm
Boat Name: SL Nyitra
Location: Northeast Ohio, USA

Re: Steam Atomizing Burner

Post by cyberbadger » Mon Mar 01, 2021 11:46 pm

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
User avatar
barts
Full Steam Ahead
Full Steam Ahead
Posts: 926
Joined: Wed Nov 18, 2009 6:08 am
Boat Name: Otter, Rainbow
Location: Menlo Park, CA
Contact:

Re: Steam Atomizing Burner

Post by barts » Tue Mar 02, 2021 12:27 am

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
-------
Bart Smaalders http://smaalders.net/barts Menlo Park, CA
Post Reply