New boiler for a friend

[Rainer]

Hello All,

Today I have 3D drawn a boiler for a friend of mine. He gave me his paper drawings.
This is for a future boat project. All this will take some time.
But best of all, he already found a professional welder who is willing to do the job including the German TÜV examination.

Steam drum diameter = 273 mm
Mud drums diameter 137 mm

About 6 m² (65 sq feet) heating surface

[PeteThePen1]

Hi Rainer

I do like your CAD drawings. That looks vaguely like the Yarrow style pressure vessel that I am attempting to turn into a boiler (Long boring story not for the Forum!).

For various reasons (all daft ) I actually have two pressure vessels and casings, so I have been trying to work out which one to use. My key question, like the perennial question about how much steam/water does a given engine use, is how does one work out the effective heating surface area of the pressure vessel?

I have looked at the Steamboating Guide (SBA) and it would appear that one should use 75% of the surface area of the tube and drums. I have assumed that the ends of the drums can be ignored as they are usually embedded in insulation or disappear into blow down or feed valves. However, I seem to be coming up with much a smaller figures for the one boiler for which I have drawings and a stated figure for effective heating surface. As you can imagine, I am a bit puzzled.

So do you, or any of the Forum Fellows have any thoughts to add?

Regards

Pete

[Mike Cole]

Hi Peter

The 3 drums and tube layout is the same as my beaver designed copper boiler. Although mine is a lot smaller(and lighter) than yours.

[Urs]

Hello Reiner
Do you know how much the boiler will cost? I tend more and more to buy also a watertube boiler.
6m2 heating surface is to match for my semple 356 DL but maybe a bit shorter......
It would best for me if I I could attach to a boiler production.
You must not repeatedly reinvent the wheel!
I would be very pleased to learn more!
Best regards, Urs