Steam Thistle Clauran

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fredrosse
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Re: Steam Thistle Clauran

Post by fredrosse » Sun Apr 26, 2020 9:15 pm

A couple of things you probably know already:

Steam for atomizing oil needs to be dry, and passing the atomizing steam through a coil in the furnace will superheat this steam very well. About 24 inches of 1/4 inch outside diameter stainless steel tubing (Type 304, or 316) does the trick in the furnace, but you can sometimes get outrageous high steam temperatures. If you put the superheat atomizing coil further downstream in the flue gas path, then its coil length needs to increase (maybe 3-4 feet of tubing in the stack base), and then there is little fear of getting 1000F steam temperature. Stainless coil is good for very high temperatures, but if there is a valve or brass component downstream of the superheater there may be temperature/materials issues.

When atomizing steam is not available during startup, you can use Propane Gas to do the atomization, one of the many ways to get up enough steam to use steam atomized oil burners.
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TahoeSteam
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Re: Steam Thistle Clauran

Post by TahoeSteam » Sun Apr 26, 2020 10:01 pm

That is sage advice Fred.

Superheat makes a big difference in fire quality, especially if you experience a little high water or carryover. The superheater helps to boil that carryover into steam rather than putting the fire out if it were able to come over as water.

Propane for initial steam-up atomization is exactly what we do on the big boat to get steam up. We usually can have the engine starting to warm and turning over within 20 minutes of lighting the match.
~Wesley Harcourt~
Check out the steamboat and steamSHIP videos on my YouTube page: https://www.youtube.com/c/wesleyharcourtsteamandmore
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RNoe
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Boat Name: Clauran
Location: Northern Oregon

Re: Steam Thistle Clauran

Post by RNoe » Mon Apr 27, 2020 12:29 am

Gents:
Many thanks for your input on dry steam for the atomizer.
That has also been my experience from years of firing full-sized oil burning steam logging locomotives.

Happily, the Blackstaffe boiler has a steam dryer for the atomizer built into the design. I will use it. It takes steam from the steam dome which extends up into the stack, and runs the line down through the fire space to the atomizer valve at the aft end of the boiler. A well proven design.

And the pressure regulated atomizer steam controller is one that was successfully used for several decades with an identical Blackstaffe boiler in S.L. Maggie.
So no reinventing the wheel here. Just installing a proven design in a proven system. "How lucky I am", I said, hoping it all works correctly again...

And yes, I have a propane fuel setup for cold fire-up. And if no propane is available, the diesel/kerosene fuel tank/system can be pressurized with a built-in hand pump for cold firing. I know such hand pumps were normal cold start-up methods for some of our west coast steamers in past centuries. I probably will never use that, but just in case... 'Never know when I might be "wilderness steaming" here in the USA.
Not quite like the UK, perhaps?

Pic attached of the 1 pound propane fuel tank in position. I will carry spare tanks aboard the boat.
It is easily replaceable or refillable from a larger standard BBQ tank.

Today I removed the new burner assembly and made 5 changes/corrections/improvements defined during the first steam up.
Next is to fabricate a bracket to hold the atomizer-regulator assembly.
Feels good to get this done.

And fun to have this all coming together.
RussN
Burner 4 sml.JPG
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RNoe
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Boat Name: Clauran
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Re: Steam Thistle Clauran

Post by RNoe » Wed May 13, 2020 5:52 pm

Oil burner atomizer control improvement:
The needle valve I installed for the atomizer control (orange handle visible in the photo in my previous post) is not sensitive enough and makes it difficult to maintain a small "spot" fire.

So I serviced/restored the old pressure controller from the original SL Maggie and installed it on SL Clauran.
Pics below show installed pressure controller (old green painted dome) and associated plumbing.
The orange needle valve controls steam for the maximum firing, and the small brass knob provides steam for the "spot" fire.
The top of the green dome is connected to boiler pressure and will shut off the "max" steam flow when the adjusted pressure is reached.

It still needs to be tested and adjusted, but knowing it worked for decades before with the same boiler design gives me some confidence.
We will see...
RussN
Burner control sml1.jpg
Burner control 2.jpg
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