thermosiphon tubes

A special section just for steam engines and boilers, as without these you may as well fit a sail.
User avatar
DetroiTug
Full Steam Ahead
Full Steam Ahead
Posts: 1863
Joined: Fri Nov 27, 2009 5:56 pm
Boat Name: Iron Chief
Location: Northwest Detroit

Re: thermosiphon tubes

Post by DetroiTug » Thu Jan 18, 2018 8:44 am

I think once this is actually laid out on paper or CAD, it will be apparent there is no advantage to it, rather the opposite.

In most Firetube boilers, the aim from the designer is to add as many tubes as possible with required spacing to increase the overall heated surface, this results in tubes that are in close proximity to one another. To add an additional tube to the exterior of each tube would require additional spacing which would result in fewer tubes or a larger overall shell diameter to maintain the same amount of overall heated surface. An increased shell diameter would benefit more by additional firetubes.

What is being sought with the outer tube is already happening, each tube is surrounded by neighboring tubes in a hexagonal pattern forming a column around each providing a path of internal circulation. So much so that in the case of the Stanley Firetube boiler which can have roughly 500 to 1000 firetubes, if overfired while low of water, it will lift the water off the crown sheet and damage the lower region of the tubes and joints near the center of the boiler.

If high output and fast circulation is a consideration, have a look at some of the various water tube designs.

-Ron
User avatar
DetroiTug
Full Steam Ahead
Full Steam Ahead
Posts: 1863
Joined: Fri Nov 27, 2009 5:56 pm
Boat Name: Iron Chief
Location: Northwest Detroit

Re: thermosiphon tubes

Post by DetroiTug » Thu Jan 18, 2018 8:45 am

double post deleted
lostintime
Warming the Engine
Warming the Engine
Posts: 82
Joined: Tue Nov 07, 2017 1:10 am
Boat Name: No Boat Yet

Re: thermosiphon tubes

Post by lostintime » Thu Jan 18, 2018 1:17 pm

I think now that what im seeing is #2 in fredrosse's post, when it's flooded the tubes stop being able to pump effectively and vapor production drops. I think I'll just take your guys advice and run longer flooded tubes
May predictive auto spell be damned
Post Reply