Quad versus twin compound

A special section just for steam engines and boilers, as without these you may as well fit a sail.
User avatar
DetroiTug
Full Steam Ahead
Full Steam Ahead
Posts: 1706
Joined: Fri Nov 27, 2009 5:56 pm
Boat Name: Iron Chief
Location: Northwest Detroit

Re: Quad versus twin compound

Post by DetroiTug » 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
TriangleTom
Full Steam Ahead
Full Steam Ahead
Posts: 112
Joined: Mon Oct 31, 2016 5:57 pm
Boat Name: No Boat Yet
Location: Yukon, OK

Re: Quad versus twin compound

Post by TriangleTom » Mon Mar 16, 2020 3:43 am

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
User avatar
Lopez Mike
Full Steam Ahead
Full Steam Ahead
Posts: 1808
Joined: Wed Dec 07, 2011 6:41 am
Boat Name: S.L. Folly
Location: Lopez Island, Washington State, USA

Re: Quad versus twin compound

Post by Lopez Mike » Mon Mar 16, 2020 6:57 pm

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.
If you think you are too small to make a difference, try sleeping with a mosquito.
Dalai Lama
Post Reply