Kevan
Seasoned Member
Posts: 138
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Post by Kevan on Oct 25, 2020 21:35:08 GMT
I was pondering on the possibilities of a model of a fireless industrial locomotive. Two things I need to figure out:
1 What kind of pressure vessel do I need to contain enough steam/ superheated water for a decent run
2 how to generate enough superheated water to fill the reservoir!
Does anyone know if this has been done before!
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mbrown
Elder Statesman
Posts: 1,713
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Post by mbrown on Oct 25, 2020 21:59:49 GMT
I fear that the laws of thermodynamics will be against you! The volume of water you could carry would be too small to hold enough latent heat. If you take the fire out of a full size loco it will cover quite a distance before losing all its pressure - on a model, without the fire the pressure has gone in seconds.
Besides, you still have to find a source of water at high temperature to recharge the reservoir, and that would take a while to get up to temperature. Full size fireless locos were used at plants where a substantial supply of very hot water was permanently on tap - like paper mills.
Malcolm
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Post by Roger on Oct 25, 2020 22:37:26 GMT
I agree with Malcolm, the Physics of this doesn't scale, you won't get a decent run. That's because the volume changes at the cube of the linear dimensions.
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Kevan
Seasoned Member
Posts: 138
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Post by Kevan on Oct 25, 2020 22:41:41 GMT
Ok how about I cheat and use a liquified gas such as CO2 or nitrogen? The much lower boiling point would effectively allow more energy in the same volume problem being very low system temperatures rather than very high?
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mbrown
Elder Statesman
Posts: 1,713
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Post by mbrown on Oct 25, 2020 22:50:32 GMT
Some loco builders like Baldwin built compressed air locos for use down mines. The reservoir would be far too small in model sizes but you could cheat and have a big air tank on the driving car.
Only an extension of having a water tank on the drivers car, I guess.
But wouldn't you miss the smell of coal and oil (see another string of correspondence!)
Malcolm
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Post by Roger on Oct 25, 2020 22:50:40 GMT
I think you'd need some kind of heat source for liquified gas to work because it's going to freeze the cylinders otherwise. That kind of defeats the object of it being fireless.
If you want the look of a fireless locomotive, then electric is an option. At least that's truly fireless.
Alternatively, I suppose you could have a gas fired boiler and a fan to force air through it and have the chimney come out of the bottom. With gas you wouldn't see any smoke. However, that's not fireless so it defeats the object.
Even in 10-1/4" gauge, I don't think it would be viable as a fireless locomotive that would do much useful work, but you'd have to do the analysis to find out.
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Kevan
Seasoned Member
Posts: 138
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Post by Kevan on Oct 25, 2020 22:53:51 GMT
Ok
Maybe I should just park this under dumb ideas😟
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Post by steamer5 on Oct 26, 2020 0:15:37 GMT
Hi Kevan, Use a dive cylinder as your air source. You would want the largest you can find, & likely 2 or more fitted up in a couple of trolleys. Long story but a now deceased club members son does that on a 4” traction engine, sorry no details. I haven’t seen it but have heard it works ok, how long it runs I don’t know..
Cheers Kerrin
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Post by flyingfox on Oct 26, 2020 7:34:29 GMT
Greetings, the fireless locos that we had at Shellhaven oil refinery, used steam from the hp steam main at 250 psi to charge the receiver, which was half full of water When in use, as the pressure fell, more of the water boiled, until pressure fell to about 25 psi, when they were recharged. Usually, they were left on charge overnight, and given a "top up" at lunch time, and would cheerfully do a full days work. Regards Brian
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Kevan
Seasoned Member
Posts: 138
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Post by Kevan on Oct 26, 2020 7:39:48 GMT
Brian
Thanks for that. So the pressure vessel would need a hydrostatic test at 520 psi I can see that causing issues with boiler insoector🤣
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Post by delaplume on Oct 26, 2020 8:40:54 GMT
As a young boy I remember seeing a fireless loco shunting in the yards of Huntley & Palmers biscuit factory on the East side of Reading ( mid to late 1950's ) en.wikipedia.org/wiki/Bagnall_fireless_locomotives_(preserved)As an alternative system to generate steam without a fire you might like to consider the HTP ( High Test Peroxide ) method used experimentally by the German Kriegsmarine and the British Royal Navy to power submarines.......and I believe the old Soviet Navy used it to power some of their torpedoes....On the other hand after reading this you might not !!! }-------- en.wikipedia.org/wiki/HMS_Explorer_(submarine)
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Post by cnr6400 on Oct 26, 2020 16:38:43 GMT
If you have enough uranium in your odds and ends box, you don't need a fire or hydrogen peroxide either!
(might as well go big, or go home.......) just joking of course!
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Post by andyhigham on Oct 26, 2020 17:34:41 GMT
The same technology is still in use. Steam raised from Hydrogen peroxide. youtu.be/YR1iG_tuqMgSteam raised from superheated water. The front of the bike hinges upward to allow the burner to be fitted to the front of the pressure vessel and heat the water. youtu.be/lK2vLLQ7GbI
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Post by h2ogasnz on Oct 27, 2020 8:13:42 GMT
An option would be to build a model of a fire-less loco that has a normal boiler that is gas fired so there was no smoke and therefor no giveaway that it was a normal loco...
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Kevan
Seasoned Member
Posts: 138
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Post by Kevan on Oct 27, 2020 9:35:52 GMT
I must say the hydrogen peroxide route looks interesting for a big steam generator then fill the loco reciever. Mind you I suspect it would prove fatal. Not so much from failure as the effect on the club’s ageing boiler inspectors🤣
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Post by Roger on Oct 27, 2020 11:52:27 GMT
Another alternative would be to make the locomotive exactly as it is in full size and have a separate Gas fired boiler camouflaged as a wagon. Since that would be completely non prototypical, it could be a flash steam boiler with a completely automatic control system. That could borrow ideas from steam hydroplanes, but with only a small amount of superheat. That would be a really interesting project all of its own!
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barlowworks
Statesman
Now finished my other projects, Britannia here I come
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Post by barlowworks on Oct 27, 2020 14:43:12 GMT
Instead of steam would it be possible to charge the vessel with compressed air from something like a 12v air compressor used to inflate tyres. Just a thought.
Mike
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Post by Roger on Oct 27, 2020 18:02:41 GMT
Instead of steam would it be possible to charge the vessel with compressed air from something like a 12v air compressor used to inflate tyres. Just a thought. Mike I don't think it would last more than a minute or two I'm afraid.
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Post by andyhigham on Oct 27, 2020 18:15:22 GMT
A 2 litre vessel filled with compressed air at 6 bar would contain 128 litres of air A 2 litre vessel filled with water at its boiling point for 6 bar (165C) could liberate 3400 litres of steam
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Post by chester on Oct 27, 2020 18:46:12 GMT
At about £250 you can get a 12 litre bottle filled to 300 bar of breathable air and a refill is about £10 at a dive shop or gun shop
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