BBC Radio 4: Steam Driven

[SteveW]

Guys,

I've just caught a good little radio program about the new developments in steam. I read a while back that Switzerland were re-introducing steam which, using modern technology, can be very competitive against diesel.

Check out:

www.bbc.co.uk/radio4/science/pip/78kt9/

And with the right software you can listen again

[SteveW]

Guys,

Its been a couple of days now, has anyone actually listened to this one?

If you haven't (I listened both live and via the net) consider injecting steam into the fire box to improve efficiency. What they're doing is using the fire box more as a gas producer and supply air ABOVE the fire to burn it. You older guys may remember producer gas generators during UK:WW2 as a petrol replacement (I did it in science classes) . Hot carbon + H2O makes some form of cumbustable gas.

One of the many advantages being a cooler fire that isn't blown apart by a gale of air and doesn't therefore get blown up the chimney and cause fires.

[Richardw]

Steve

I think you have to inject the steam into the ashpan below the fire in a GPCS system and supply most of the combustion air above the fire, usually through extra air holes in the firebox sides in addition to through the fire hole door. There has been a fair bit written about this and it has been used successfully in a basic form on the Kirklees Light Railway for some years now in addition to the other global experiments with it.

The KLR have a write up of their use on the locomotive page of www.friendsofklr.co.uk/ The biggest single advantage to them has been a significant reduction in clinker in the fire.

It does seem that you also need a very good draught for it to work and most users of GPCS that spring to mind have used Kylchap or Lempor type exhausts to get the extra draft as well as reducing backpressure.

Anyway that is enough from me as I am no expert, just an interested amateur. Hope my little rambling is of interest to some.

Regards
Richard

[baggo]

There's a page here about gas producer systems fitted by Hunslet at

www.trainweb.org/tusp/last30/hunslet.html

The article appears to have been written in 1963 so it's pretty old technology.

Useful info for anyone interested in steam technology and recent developements in steam locos can be found at

www.trainweb.org/tusp/index.html

John

[JohnP]

The gasses produced by injecting steam into an incandescent carbon based fire are hydrogen and carbon monoxide. I think it's just
H₂O + C = CO + H₂

Hmm that'll be interesting to see if the subscripts work!

As mentioned on the program, this reaction is endothermic, so if you don't mix air with the steam the fire will go out.

The point I wanted to make is that CO is not nice stuff, so if anyone tries a gas producer firebox, please be careful.

It was nice to see the BBC using some technical terms and not assuming that their audience can't grasp complicated topics!

JohnP