In full size engines, a hole in the coal fire will create a white wisp in the stack. And yes, wetter steam will give a whiter plume and will be VERY white if pulling water. Messy too. I wonder if you run the water a little lower, is the exhaust still as white? Is it a mushy sound or sharp?
I have been reading with interest in these emails of the "black magic" needed to keep these butane and alcohol fires running and now I am wondering if you might be dragging too much cool air in from under the fire. In full size coal burning engines, the only air drawn in through the fire passes through the coal fire itself and even working hard, with injector on full bore, we can make steam while heading up hill. That would be in a '27 Shay and a '20 Baldwin 2-6-2 with a three car passenger train. In other words, on real engines, the harder it works, the hotter the fire gets. I sounds like this will not hold true in the little engines. But can it? On a full size engine the fire itself must be changed in proportion to load and weather conditions. Working hard, the fire must be relatively thick and even thicker in winter where the cold air has quite an effect. Sitting in the station or running with a lighter train, the fire can be much thinner. We also use dampers and the fire box door itself to control the heat of the fire. So some how, in looking at the miniature engines, is there a way to regulate heat of the fire beyond messing with the blower? It sounds like you are all dealing with a fixed fire (a fixed amount of heat produced) and you must adopt your operation around that. The fireman on a prototype locomotive was able to regulate the amount of heat (within reason) in response to conditions. I'd look at a clear stack while working hard as the ultimate goal and a good way to measure changes to the fire. Does anyone have an engine they'd like to sell to me cheap so I can experiment for myself? I have a DEE casting set, but have not had time to work on it. www.njmt.org ----- Original Message ----- From: steve speck <[EMAIL PROTECTED]> To: Multiple recipients of sslivesteam <[EMAIL PROTECTED]> Sent: Tuesday, February 25, 2003 10:20 PM Subject: Re: Alisan plume? > I have a Mikado and a RH #24. The #24 always has a plume but the Mikado > seldom does. I have ben told the reason is that the #24 is giving off much > more saturated (wet) steam, while the Mikado gives off much drier > steam. I guess it makes since, the Mikado has 5 flues pulling fire > through them via draft while the #24 only has one gas fired flue. Even > though the #24 has a great looking plume, the Mikado blows much more > through the stack and is much hotter. I would think that while the wetter > steam looks better out the stack, the drier steam is more efficient. Any > other thoughts on this would be appreciated. Steve. > > > At 05:38 PM 2/25/03 -0800, you wrote: > >OK, another naieve question. > > > >The Steamlines Shay, Ted's Roundhouse 7/8th scale Porter, and the Frank S > >all have obvious plumes from the smokestack during cold weather. This Alisan > >Shay runs almost plume free. The pop offs offer evidence that steam is > >powering the critter, but only episodic plumes occur from the smoke stack > >and those usually when the engine starts from a stop. Any hypothesis occur > >to any of you, let me know. Is it a real efficient engine? Does the exhaust > >cool too much to cause a plume or could the exhaust be too hot and the steam > >dry? > > > >Curious in Oregon > > > >Gary - Photos of Alisan shay look like the loco is cold except for the pop > >offs. > >http://www.angelfire.com/or/trainguy > >http://community.webshots.com/user/raltzenthor > > > > > >
