Page 2 of 2
Re: Quad versus twin compound
Posted: Mon Mar 16, 2020 2:51 am
by DetroiTug
Exhausting up the stack should be done with a nozzle to increase velocity, the little steam cars did that to maximize the effectiveness. Traction engines and locomotives did this as well. How big? What shape? I think only R&D would answer that.
Ron
Re: Quad versus twin compound
Posted: Mon Mar 16, 2020 3:43 am
by TriangleTom
DetroiTug wrote: ↑Mon Mar 16, 2020 2:51 am
Exhausting up the stack should be done with a nozzle to increase velocity, the little steam cars did that to maximize the effectiveness. Traction engines and locomotives did this as well. How big? What shape? I think only R&D would answer that.
Ron
I believe that in locomitives, the most effective exhaust blast nozzles were of the Kylchap design.
This page and the attached site has some really good information
Re: Quad versus twin compound
Posted: Mon Mar 16, 2020 6:57 pm
by Lopez Mike
For several reasons including efficiency, boiler cleanliness and that I steam mostly on salt water, exhausting up the stack isn't going to happen.
The question for me is how to obtain an air blast in the most efficient way. Maybe the centrifugal automotive supercharger. Maybe an engine crank driven pump like a vane type or a roots blower. Automotive smog pumps come to mind. I've even given some thought to direct drive of a propellor in the stack. This leads to Heath Robinson/Rube Goldberg nightmares with U joints, chains and whatnot.
Maybe copy full sized practice with a small Stuart 3/4 x 3/4 twin blowing into the ash pan? The thermal efficiency of small engines must approach zero on a good day but this is intended as a sort of "afterburner" to surge away from challengers.
Hmm. I smell a thread hijack. My apologies to the original poster.