Model Boat Mayhem

The Shipyard ( Dry Dock ): Builds & Questions => Steam R&D: => Topic started by: KBIO on April 11, 2021, 01:05:42 pm

Title: Water tower type boiler
Post by: KBIO on April 11, 2021, 01:05:42 pm

Hello!
Just to present you my new boiler .
The high part is 115mm x 60 high.
The bottom part is 90 mm x 80 high.

It is based on the water tower shape but the inside is quiet different. I have choosen to set it with vertical boiling tubes instead of horizontal ones.
The reason is that I have a bigger surface in an identical volume , exposed to the flame .
Ex : Available length on the furnace where to weld boiling tubes = 7 cm.
      - The calculations are made for the the  same ID furnace and same 6 mm boiling tubes.


Let’s take 7 ea horizontal 6 mm OD tubes welded inside the 32 mm ID furnace  > 32 mm X 7 tubes = 224 mm exposed to the flame.
Let’s take 6 ea   vertical    6 mm OD tubes  x 50 mm long inside the same furnace  > 50 mm X 6 tubes = 300 mm exposed to the flame.
I have 33% more surface with vertical tubes.  . Obviously , without calculating the heating surface , we can see that vertical tubes will produce more steam.


The other reason why I favor vertical tubes is that they are always supplied with water from the bottom and that the column of water along side a tube is heated , lifted and vaporised up to the top of the boiler. The trip of the water inside a 50 mm tube is longer than the one in a 32 mm One. So , the steam production remains good as long as there is some water in the boiler.
At contrario in a boiler with horizontal tubes , the performance declines when the water level goes down and leaves the tubes above the water .  The flame then , heats a dry tube producing nothing but acting as a kind of a dryer . On top of it, dry tubes in contact with flame is not recommended.


Another trick,  I place my tubes , bottom/up excentred , in a way that the flame is disturbed (see the drawing) , and «  licks » a bit more the boilers tubes. Is is efficient ? On the paper , it looks like it is ! In fact ?  It probably does not make too much of a difference but why to make it easy if it’s possible to make it difficult ? ! ;-))


The only difficulty in building this boiler is to be very carefull in positioning the vertical tubes. They have to be line up properly. If not , it may be tricky to weld the last one . Like it happens to me once !
The pics show the different steps of the manufacturing.
Regards.






The first  videos show a test with a 20 cc very badly machined down Brunel engine and leaking as much as it can ! The worst deal I ever made on Ebay!
I hardly stand 1 .2 b @ 600 rpm with a 130 g/h blow torch. I have good hope to improve the performances when I shall have fixed this « scrap » and with a 300 g/h blow torch.
Finally, after fixing the leaks and , milling the sliding surfaces , I end with virtually no leak but a tiny one on the top cap. The best I can achieved is 685 RPM @ 3 b gauge solid !
Autonomy = +/- 23 min. Not bad for such a boiler !


The second one shows a 8/9 cc TVR Graham running @ 1300 RPM and 3 b gauge steady. Blow torch : 130 g/h


I am quiet happy with the performances of this boiler and so much I am that , I offered  myself a  St Emilion to share with  friends.
You are my guests !
The little sister is on going. I mean the boiler …. but also the bottle should I say !!
I let you know the result later on for sure !
Best regards.
Title: Re: Water tower type boiler
Post by: KBIO on April 11, 2021, 01:22:16 pm
Some more pics of my trials.
The Brunel engine on maintenance and some videos of the performances.
A smaller boiler version of the boiler is under construction.
Thanks for watching.
Regards ! :-)

https://youtu.be/cH-34g1-v_g (https://youtu.be/cH-34g1-v_g)
https://youtu.be/MrHnekXZ26M (https://youtu.be/MrHnekXZ26M)
Title: Re: Water tower type boiler
Post by: Captin Kipper on February 12, 2022, 08:39:27 pm
That looks a good Idea I think I will build one , but just a normal 4" vertical with your vertical water tubes in the flue.  Thanks for sharing


Brian
Title: Re: Water tower type boiler
Post by: KBIO on February 13, 2022, 08:28:37 am
Hello Brian !
Conventional shape works the same with a slightly bigger water volume. ok2
I just suggest that you make a protruding dome for the steam outlet in order to minimize the water priming.       
Title: Re: Water tower type boiler
Post by: KNO3 on February 13, 2022, 06:40:41 pm
Is the blue engine made by Anton? Please show some more pictures of it..
Title: Re: Water tower type boiler
Post by: Captin Kipper on February 13, 2022, 08:38:28 pm
 


Thanks for the advice re the steam dome. I will bear that in mind when building my Boiler.  if I go down that route I will probably drill a series of small holes under the dome. [size=78%]


Best Regards   
Brian[/size]
Title: Re: Water tower type boiler
Post by: rhavrane on February 13, 2022, 08:43:29 pm
*** Update  *** Bonjour,

I personnaly didn't know any tri from Anton and my friend Giovanni shared with us also different vintage Anton twins only:        https://www.youtube.com/watch?v=Gew_bPlvS28&t=66s (https://www.youtube.com/watch?v=Gew_bPlvS28&t=66s)

This is why, thanks to Calin, I am happy to discover this machine made by Anton, now retired.
Title: Re: Water tower type boiler
Post by: KBIO on February 14, 2022, 08:23:43 am
Good morning !
As Anton gives the name of a gemstone to each of his engines , this one  is called "TURQUOISE" .
It is a 6,7 cc . The period with latéral pistons sleeves made more or less in 2010.
Around 35 units has been built but , mainly sold to Germany & Switzerland. Other tri-cylindres engines are Typhoon.
(We can find an historic of ANTON on my Forum :https://modelismenavalvapeur.forumactif.com/f126-historique )
Sorry I don't remove the engine out of its boat to have better picture : too much work ! :embarrassed:


Just a quick video for the sound (but no oil smell %) )
https://youtu.be/RSydi9A9Zr4


Have a nice day !
Title: Re: Water tower type boiler
Post by: DBS88 on February 14, 2022, 02:34:03 pm
Wow that engine really is a gem, thank you for sharing :-))
Title: Re: Water tower type boiler
Post by: KNO3 on February 14, 2022, 10:57:28 pm
Thank you Yves!