Love that...
Yeah sorry about your unfortunate learning experience there.... "Hey! Is there an easier way to get that dam ash sled outta there? What in tarnation were they thinking when they designed this unforsaken hunk of steel?!"
======================================================================================================Retro_Origin wrote: ↑Wed. Aug. 10, 2022 8:26 pmSo rather than start a new thread (as I've been doing enough of lately!), I'd like to bring up the concept of heat transfer and maybe learn a few things.
My wife and I went to the pioneer tunnel this weekend (which was great) and I snooped over to look at the little steam engine they have there that they use for their train rides. The guy showed me the firebox and then I noticed the tube passageways for heat transfer...this sparked my 'train' of thought...the exhaust had to pass through those small tubes through the boiler to get to the stack. This design is also reversed (right?) as in the example of the really big boiler that Stoker Don posted a while back at the Direnzo breaker, where the water tubes were inside the firebox(?) to accept rising heat.
So 'laminar' flow is understandably the worst for heat transfer, as I understand. All AA and AHS owners are always pretty ecstatic about the effective heat transfer via the turbulence of exhaust gasses...but this allll has me wondering...
Is my Keystoker about the worst design for heat transfer since there is very little swirling action and the openings are medium-large?
Is the AA design even better because the burning coal bed also has direct contact with the wet walls?
Didn't EFM go from a 'tube' heat exchanger to a plate style? If so, why? (Duel fuel purposes?)
How can fast moving swirling gasses be an effective way to transmit heat?
How is the AA design 'double exchanging', the fan draws through the center and then when it makes the 180 turn is when it finally hits the boiler walls, in the vertical swirl chamber there isn't excessive surface area for exchange, is there?
Anyway, just looking for some info/principles on turbulators, best type of heat exchange, good designs forgotten or old designs improved....all that jazz.
This is very helpful, thanks Rob!
Ok yeah, are you fabbing this up yourself? Or is that an existent boiler?
Pretty sweet! That's every man's dream! Was there any noticeable heat transfer difference than from previous boilers you've dealt with? (as in, were you burning significantly more or less consumption, or maybe stack temp vastly different) I know my friends Harman stovepipe was cool enough to leave my hand on for good, probably less than 140! Although that's a smaller unit than my boiler...
Right but since that's not really measurable by me...my questions aren't really directed at "how can I get the most out of my coal" but rather, "what are the principles for best heat transfer, and why do different manufacturers seem to be taking significantly different strategies?"
I imagine the Keystokers all have a similar design. So if yours is like my uncle's, the exhaust has to leave the burn chamber towards the bottom. This design exploits natural convection in it's favor. The hot gases off the burner rise and give up heat to be able to sink and exit at the bottom. With this concept in mind, I added an exhaust gas diverter to my handfed Clayton. The proof that it worked was in the numbers. It lowered the exiting flue gas temp and increased the stove temperature. So no, I don't think it's a bad design at all. A bad design would have the exhaust gases go straight up and out.Retro_Origin wrote: ↑Wed. Aug. 10, 2022 8:26 pmIs my Keystoker about the worst design for heat transfer since there is very little swirling action and the openings are medium-large?
Better? I would say no. The radiated heat from the fuel bed is still accounted for whether it's in direct contact or not. The advantage with it being in direct contact is that the walls would stay cleaner. In a big box design with slow moving gases fly ash has an opportunity to build up and insulate the heat transfer surfaces. I would do a quick go over with a wire brush at almost every tending to keep the interior walls clean on my Clayton.Retro_Origin wrote: ↑Wed. Aug. 10, 2022 8:26 pmIs the AA design even better because the burning coal bed also has direct contact with the wet walls?
Turbulence and keeps the transfering surfaces clean.Retro_Origin wrote: ↑Wed. Aug. 10, 2022 8:26 pmHow can fast moving swirling gasses be an effective way to transmit heat?
That's more fore cleaning dust and particulates out of the exhaust stream so your stove pipe and chimney don't get clogged up. But it does double duty with additional heat transfer area before leaving the boilerRetro_Origin wrote: ↑Wed. Aug. 10, 2022 8:26 pmin the vertical swirl chamber there isn't excessive surface area for exchange, is there?