Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[KBIO]

Good evening!  
I a am glad to present you my Pierre Louis.
She has been built 12 yearas ago and since then , sailed once only.
I had problem to start this 3xpension from JMC, as I could not evacutate the condensation fast enough. The electric starter and a poulie at the end of the cranckshaft solved this .
The other concern I had/have is the fact that the gas tank is in contact with the boiler. Thus after a while , the temp rises in it as well as the pressure. It comes to a point where the pressure inside the gas tank is higher than inside the boiler.
As the regulator is set for a differential pressure 2.5B (gauge) , it becomes un-operational quite fast and the burner is getting stronger & stronger as the pressure builds up.
So I intend to move the gas tank in front of the boiler , above the burner and get away with this uncontrolled pressure problem.
As usual, I forgot the weights at home, that is the reason why the propeller cavitates a bit.
But I am very pleased with the Stephenson reverse gears on this type of engine.
thanks for looking  
Cheers!
http://www.youtube.com/user/22herge22?blend=16&ob=5

[knoby]

absolutely superb    so nice to see a launch thats not varnished or white.
Hope you manage to get her running troubles sorted out, she is well worth the effort

Glenn

[john s 2]

Have you thoght about using a gas pressure regulator? This would keep the pressure to the burner constant.
Or how about using a steam pressure reg as sold by Forest steam? This simply connects to the steam pipe
and gas pipes turning the flame down as pressure rizes.It is of course adjustable. Finally why not put some
ceramic fibre between the tank and boiler.A plumbers heat mat could be used folded as required. The steam
pressure reg would also extend run time as there would be no loss of steam through the safety valve.John.

[derekwarner]

KBIO ....I thought that you had previously used the ANTON V70 series gaz regulators.............in another build......with good success..........

In those French steam WEB sites you provided...display a number of examples of the same JMC triple expansion engine....& I cannot place seeing any with the engine pulley

Is the condensate issue in the tube work prior to the engine .... ...or the stream condensing in the cold engine? ............... Derek

[Bernhard]

  what a boat........

[KBIO]

Good morning.
I ow you some explanations:
This pic of the complette set up will help in the  undesrtanding if you follow the gas line:


I use a single membrane  gas regulator on the gas line. The problem of these regulators is that the surface in contact with the steam is the same of the other side in contact with the gas.
It works the following maner:
i.e: Regulator set for 3 bars ==> when the pressure of the boiler reaches 3 bars, the gas supply to the burner is closed and the gas flows through the pilot line only.
    The pressure acting against the boiler's one is (+/- 1/2bar inside the gas tank) + (2.5 bars spring force) = 3 bars.
Now, consider that the pressure builds up in the gas tank and reaches 3 bars while you still have 3 bars inside the boiler.
There is (3 bars gas pressure + 2.5 bars spring force = 5.5 bars) against a boiler pressure which must be around 3 or 4 bar at this point. No more regulation => the gas flows , full stream, rising the pressure in the boiler, thus rising the temp, thus rising the pressure, thus..... and so on.
Because of the proximity (contact) with the boiler , the pressures involved are completly out of the purpose for which the regulator is designed for.
So , I shut off and move the gas tank away.
As John says, I can isolate the tank from the boiler with a sheet of insulated material, but I can move the boiler a bit only. The gas tank being stucked in a slot => gain of 3/4 mm only.

Using a pressure reducer will provide a constant gas flow to the burner, but will not help the pressure building up in the gas tank.

..or the stream condensing in the cold engine?
Yes Derek, the problem is the steam condensing in the two other cylinders before the engine reaches the good temperature. By turning the propeller as fast as I can, by hand, does not allow a quick warm up of the complete engine. The steam cools down faster than it is supplied.You can see the poulie I made on the pic #2 It is not delivered with the engine. The belt comes from an old printer!
So , the "trick", I use is doing well! Not conventional in the steam world but do not repeat all over the place! . I am the only one using it in France and I sail while the others are cutting their fingers trying to warm up! I know one friend who by-passed the HP cylinder but it is not a triple expension anymore!
I use Anton regulators with success  in my other installations , but the one I show you here,  is the only one with the gas tank touching the boiler.
I hope , you understand my explanations.
Regards!

[derekwarner]

Hullo KBIO

1. could you not move the gas tank to the STDB side of the vessel....& mirror the installation of the de-oiler?
2. does the 2.0 Bar pressure into the first or HP cylinder not provide suffient force to complete engine revolutions?..
3. In our Paddle Duck WEB pages we have comments *** & calculations that suggest that a triple expansion model engine requires ~~~~~~ 7Bar input & the resultant heat to minimise the pressure losses....... .....Derek

[***comments from Sandy Campbell of ACS Engineering 2009]

[KBIO]

Good evening!
To answer your question, Derek.
1) It's a good idea to move the gas tank opposite to the de-oiler! I didn't even think of it! Aging probably!
2) 2 bars working pressure is not enough , I think. For several reasons: a) boiling pressure is 100°C . @ 2 bars (gauge pressure) the temp is  130°C. So with heat losses along the system , we are getting  close to "very wet steam" and there is not enough steam velocity to keep the heat. (I am not an expert and a smart engineer  will explain better than I).
So higher working pressure (I use 3 or 4 bars (Gauge pressure) will give better efficiency ; above all in a triple expension ; keeping some pressure for following cylinders.
3) the resultant heat to minimise the pressure losses.. I agree totally and 7 bar (absolute) is realistic  .
Steam is very interesting but not so easy to understand , I realize it more and more!
Sincerely!

[south steyne]

Hi it should be possible to lag the gas tank to isolate it from the boiler heat and some timber planking would look good just a thought nice boat too
John

[derekwarner]

May sound   ....but we need to heat the mass of the model steam engine cylinders & valve blocks prior to steaming   ...but we are limited in providing a similar strategy to full size engines [steam or electrical cladding]  

Consider a large 12 volt battery   ...and a 12 volt hot air dryer/gun [like the ones for heat shrink work] would increase the bronze/brass/steel mass from 20 degrees to 60 degrees C in 10 minutes

From my work...I know metal components [hydraulic cylinder/valving under test] when functioned & heated to 60 degrees C are just tolerable to touch.....ouch!   ........

You could then introduce steam @ ~~~~~150 degrees C.....????????????????? worth a try?   ...........Derek ....just as below.....

http://www.nextag.com/norob/PtitleSeller.jsp?nxtg=36000a28050a-4CD0B990EBCBEC25&chnl=main&ptitle=677723676&tag=965526218&ctx=x%2FiIRwG1djVgbR7c6W3K2WEaGADjhlIdR4O8jqeRFHeem5nxsQT9pvk6CzG0YechWdwRc4ZudBCKE2iedissVBybYQhBfyxKLvrIIDLYCzaDAFGEJvyc%2B%2Bt%2B1dgrMExbmvtdpOccI1ecn9jOHQaBjVmoXEYzI4cXHXIXUWSIG2tqZD901sRcJQckYqFg0Vb%2BEw4ChSScJqxxDAlUBcoo37WdB2T6eJbHr9jB8kx4fmXYttHA2xn%2FgVlDMlWjZ1RQfLtkVGm%2FRHQ9jBu%2Fcqjh%2BpomS7U54NK8gTDtwKpkttSHuMmk1SmaB6H7T97i9iEv

[steamboatmodel]

Is there any way you could add/rework the piping with additional valve so that you could start up with all the inlets receiving steam from the boiler? Then when up to working temperature switch to compounding.
Does the engine have any cylinder drain valves that could be opened untill the condensation is cleared ?
Are you running a condenser on the steam exhaust?
Regards,
Gerald.

[KBIO]

Good evening.
Thank you for the interest you have for this engine.
To answer to Derek, I would say  : I try to keep myself simple & classic!
 
Is there any way you could add/rework the piping with additional valve so that you could start up with all the inlets receiving steam from the boiler? Then when up to working temperature switch to compounding.
There is a way, but I do not manage and this means more holes, piping and drilling. I want to keep the engine as close as it is originally. It as to work the way it has been designed for. This is the case.

Does the engine have any cylinder drain valves that could be opened untill the condensation is cleared ?
No bleed off valve, but I would say that the engine is not big enough to make it mandatory. Still I do bleed off on D10, but honestly, I do not see the difference. Maybe someone will clear up this point.

Are you running a condenser on the steam exhaust?
I must admit that I "virtually" grease my engines only, An oiler contents last a couple of hours with me.
I have some friends who has no oiler. They oil the engine prior to steam up and it is enough for the run. I do not totally agree with them, although there engine is well mabufactured, but everybody has his own oipinion. An engine with no oil will run , but adding some oil will help a lot. (I think! )
So when the engine is hot and the fisrt oil & condensation is out , I do not need a condenser any more. Make the experience and you'll see that the water & oil  comes at the begining of the heating only. (this goes in a rag)  After, I let my steam exhaust going thru the cheminey most of the time. The gas heat is sufficiant to evaporate the remaining.
In fact I use more oil for storage than for steaming.
But I like the exaust on the side. As I say, there is no oil in the pond. In any case I do not see more than when I use a condenser.
I let you know the way I do, it does not mean in any case that this is the best way.
Thanks and regards!

[don galfur]

    Hi KBIO
          This is Dave Gallagher from California. I don't post much.
                     Great looking launch. I attended Paul Fonlupts Aquavap event two years ago in Gemenos. I picked up some interesting ideas there for my last
            model which is kinda of a  " Super Topaz."   I really admired the French engineering I saw.  This year my wife and I are going to Steam Atlantic. Will you be bringing
           the Pierre Louis to that event? I would surely like to see it ;  I would be very interested in seeing the triple run. I have heard differing reports on Cloups engines. Pretty mixed views.
            Yours is a  lovely model. 
            Dave

[KBIO]

Hello Dave.
Thanks for your comments.
ATLANTICA is organised by Anton (F.Bretagne) so I favor ANTON's engines when I go there, but I guess that if you come,I have to do an effort , bring my 3xpension and let you play w/ it.
It will be a pleasure and anyway , it will be in my friend's camping car. Just need to buy an extra beer. Jésus, I'm glad that the camping car is using diesel instead of beer! 
I'll be glad to meet you at the same time.
note: concerning JMC engines or others : "there is no bad engine, but sometime bad mechanics. I know, I'am one!"
Regards!