[Blogwitch]

Thanks Al for the confirmation.
The problems started when Google took over and automatically raised a new account linked to Gmail and everything else under the sun. So I couldn't access my old account with all my vids on it. I have managed to get to them now, but can't add any new vids, only to this crappy new account, which I hope now is set up for showing vids.

Jens,

I see you have hit the steam everywhere barrier usually associated with the open faced turbines, imagine that in an enclosed hull, it is like emptying your boiler directly into the hull, it would be water swamped in no time.
That is why on my second unit (3 rotor) I put a collection chamber on it to send any exhaust overboard.
The vid show it running on air, but it has run on steam, and the collector worked very well indeed, but my 3.5" diameter gas fired boiler just couldn't keep up with it's requirements, I had to keep stopping to allow the pressure to build up again.

John

[bazmak]

Hi John,i put on Utube a series of images of steam locomotives
and while playing about added a few pieces of my favorite music
Further down the line they put a stop to my slide show due to
copyright infringement.The problem was not the images but one of the tunes
was not allowed.Guess where I downloaded it from.You guessed it.The Utube
free download software. Go Figure.# out of 4 of my uploads are ok but one is
forbidden in UK, etc but not in the rest of the world.Look up Gresley pacifics

[modeng2000]

All good now John, thanks.

[Mechanicboy]

Originally Posted by Blogwitch

Jens,

I see you have hit the steam everywhere barrier usually associated with the open faced turbines, imagine that in an enclosed hull, it is like emptying your boiler directly into the hull, it would be water swamped in no time.
That is why on my second unit (3 rotor) I put a collection chamber on it to send any exhaust overboard.


John

John, this was a test running the turbine hence i had not completed the steamturbine with the cover + exhaust pipe to lead steam out of the boat.


John wrote: The vid show it running on air, but it has run on steam, and the collector worked very well indeed, but my 3.5" diameter gas fired boiler just couldn't keep up with it's requirements, I had to keep stopping to allow the pressure to build up again.

---> Replace with a smaller orifice (steam jet) to prevent loss of pressure in the steam boiler and keep steam turbine running. As rule the steam turbine need a big heat of surface in the boiler or use flash boiler.

My own experience: Do not use too large turbine diameter as it requires higher vapor pressure and greater consumption. With a turbine diameter 30-35 mm will provide higher speed than a large turbine diameter. The turbine should act as flywheels as being high torque. The turbine wheel should have more turbine blades to keep steady power from the steam jet. Use ball bearings to keep the friction low as possible. Oil viscosity is critical in relation to the vapor pressure vs. speed.

I took the test with difference oils in the bearings.

Here are the tests of oils and measured revolutions per minute:
Work pressure= Mobil ESP 5W-30 / Air tool oil / Diesel oil (fuel for diesel engine as lubricant)

1 bar= 4700 / 13230 / 17600
1.5 bar= 6200 / 17900 / 25700
2 bar= 11400 / 21660 / 31500
2.5 bar= 15500/26340 / 36700
3 bar= 18600 / 28800 / 41800

As i can see the ball bearing get less friction with diesel oil as lucricant, it is sensitive for jet stream from nozzle. With high revolution above 15000, i can feel there are enough torque when trying to stop the turbine shaft.

[Blogwitch]

Jens,
Sorry I jumped in too soon in your production of a turbine, I thought it was one of those bought units that are for display only.

With regards to your comments, I can't really go much smaller as the steam jet nozzles only has a 1mm hole through it at it's smallest point. I know the problem, my boiler just isn't big enough for this engine.

Here it is running on a good head of air, about 40 psi, well before completion, on just one nozzle, so I know the nozzles I made were OK.

YouTube

I informed the chap who this prototype was being trialed for (he would be getting just a pair of two rotor ones) that he would require a flash steam boiler to run both, but he wouldn't go down that route, so his project was abandoned.

You mentioned the rotor diameter, the rotor in this one is about what you stated.

With regards to your build if I could make a suggestion. Get rid of the pressure as soon as possible after it has done it's job. I made two tangential exhaust holes for each rotor face. One about opposite from the pressure nozzle and a second at about 45 degrees after TDC. This scavenges most of the spent air/steam before it has time to get around the rotor and starts to interfere with what is being fed in.
You can just see the four holes for the fwds rotor and the two holes for the rev rotor, all are tangential to the rotor itself to 'scrape' the air /steam from it's surface and get rid of it before it goes too far.




John

[Mechanicboy]

See at drawings who i has changed some points.. Use steel shaft instead brass shaft to rotor and mount ball bearings in rotorhouse to preventing the rotor is moving sideways. Ball bearings light press in the rotorhouse and shaft snug fit in ball bearing.

[Bronzewing]

Hi
Just a point about Youtube. There is an option to view your channel as others see it. It can help to see how changes you make on settings actually work.

[WernerJ]

Hi all,

I'm new to the forum and I've read with interest this thread. I have built several gauge 1 steam turbine locomotives which run quite successfully. My latest project is the Pennsy PRR-S2. At 4 Bar, boiler and turbine produce approximately 10 Watt of shaft power at 35'000 rpm. Naturally, the drive could be adapted to power a boat. But then, propeller rpm and torque requirement (pitch ?) would have to be found out first - and you'll need an efficient reduction gear.

https://youtu.be/RPAJID1CSfM

regards Werner

[Cogsy]

Welcome to the forum Werner - you're loco looks fantastic! Would definitely like to see more.

[ShopShoe]

Werner,

That's fantastic. there are not too many turbines posted, but when they are, they're amazing projects.

I would also like to thank you for the extra work of posting text in two languages and for providing specific technical information. Those things make your post much more informative.

I wish you more success with your modeling and good welcome here.

--ShopShoe