The Steamboating Forum

My new boiler being born...

She looks hungry for wood or coal already.

More details, drawings, and pictures will be disclosed as she develops.

-CB

This new boiler ASME boiler is inspired by Manning Vertical Fire Tube (VFT) type boilers, where the firebox diameter is wider then the upper firetube area.

It is a modification of an existing design from Lund Machine Works that was for stationary purposes. I had a lot of fun working back and forth with Jeff Lund to come up with this design to reduce weight while at the same time trying to increase heating surface area.

Some specs:
Bottom O.D: 24"
Upper O.D.: 18"
Wet legs surrounding firebox
Firetubes: Qty 79 1.25" diameter
MAWP: 200PSI
1 Fusible Plug(Required by current ASME code for hand fired boilers)
Height Including Base, but not Bonnet or Stack: 61.25"
Fuel: Wood and Coal

Main steam nozzel outlets (qty 4) are 1" (I plan to probably reduce them to 1/2")
4 1.25" washouts for washout and inspection purposes.

"Unique Features"
Manning VFT style
Base/Ashpan/Ashdoor is a separate assembly - So If I want to tinker with a different Ash pan or different air "intake" arrangement I can replace and make my own without having to alter the pressure vessel itself.
Rectangular (Rounded) Firebox door

The attached drawings are preliminary and do not include all nozzles.

-CB

I wonder if that air intake/cleanout is wide enough. My Beckman VFT30 has one about three times as wide and I can tell the difference in the intensity of the fire when I close it as much as a third of the way down.

Also I would want a wider one to ease the job of cleaning out the ashes.

Lopez Mike wrote:I wonder if that air intake/cleanout is wide enough. My Beckman VFT30 has one about three times as wide and I can tell the difference in the intensity of the fire when I close it as much as a third of the way down.

Also I would want a wider one to ease the job of cleaning out the ashes.

I got "burned" before. on the grates/ash pan/cleanout area on my first 16" diam dry VFT.

That's why I had this boiler have a separate assembly that I can swap out.

I will learn how she does on land before she goes to a calm lake.

Baby steps in my mind. Get a boiler and engine combination that works on land before you put it in a hull.

-CB

Baby steps in my mind. Get a boiler and engine combination that works on land before you put it in a hull.

If you want to do this, you'll need to arrange for a realistic load on the engine. Idling the plant on shore takes nearly no steam compared to steaming in the water... and the speed at which the engine runs will affect the water pump, etc.

I find getting firing correctly on shore is great, but for overall tuning launching and running at the dock is a good way to start. If you can run wide open at the dock, she'll generally do well running free.

- Bart

barts wrote:If you want to do this, you'll need to arrange for a realistic load on the engine.

Like these loads (my vids)?





-CB

Yup... Just 10x the size w/ that big boiler.

-Bart

I want an easy steamer Bart, I am paying in weight, and startup time certainly and most probably fuel consumption on the boiler.

I plan to lag this boiler with insulation, mahogany and brass straps.

As I said in my welcome forum. I will be running non condensing and I have two candidate engines. 1 of which is from an 18ft steam launch in England, it's in the second video. It's under a good load. Not optimized for producing electricity - but a proof of concept and a good load for that engine.

I like your idea of running on the dock first, but I'm going to be doing a lot more on land first before I approach the dock....

Even when I do the first hull will be a 24-28' pontoon boat that you can get for a couple of thousand dollars. It will be my learning platform. I'll either stay with that hull form, or learn about what I want in a hull.

I like baby steps, and I like to learn things for myself.

As far as water. I have a new old stock untouched pennberthy injector that will work up to 160 PSI that I have not even tried - it's for this new boiler. I have a small simplex marsh steam pump from the 1960's. A big worthington duplex steam pump. And several other injectors that I have. One of my candidate engines also has a pump off the the crank shaft.

-CB

Hallo CB,

what kind of engine will you use, that you need so much heating surface?
As Mike wrote, the ashpan door is very small, a good value would be 20 % of the grate area.
The steam space and the free water surface area seems extremely small,
I think you will get very wet steam and maybe under forced conditions carryover of water.
Just my thoughts.

Scotty

That 20% number is interesting. When I get home in a week I'll measure my areas. I suspect my door is closer to 50% or more.