joeq wrote: ↑Sat. Mar. 03, 2018 9:40 am
OK, I had some breakfast, and have gotten over my "temper tantrum".
My whole train of thought is lost from my previous ghost post. So I'll respond to yours Paul.
You mentioned using your check damper to revive a fire by closing it, which makes me think your damper is "open" more than closed? Once your fire has been established to the hotter temp you desire, does that mean you open it back up? Fully? Partially?
You also stated that a smaller fire pot is more sensitive to draft in a 6" pipe, compared to a bigger stove. Maybe I'm viewing this incorrectly as an automotive exhaust system comparison again, in that a smaller tube hedder works better on a smaller engine for breathing, but becomes a restriction on a larger cube motor. So a
big 6" stove pipe acting on a smaller firebed, I would think to be "less" responsive. (?)
I did as FB suggested last night, and pulled my check damper out "slightly", and 8 hrs later (this morning), it appeared to work as well as dumping on a pound of magic dust. The barrel temp was down, and the firepot gauge read healthy, about 450 degrees. And it recovered pretty quickly. Curious how it would perform on a 20 hr burn, like the past few days using fines. I won't be able to experiment with that for a couple days seeing it's the week-end, and my daughter came home from Syracuse college, so we'll want to have some extra heat. But I think what you (Paul) said about the fines clogging the coal bed, and needing extra attention makes sense. Thanks guys.
Joe,
First, lets make it clear that when to use a check damper all depends on the OAT and what you want for heat output.
Also to be clear, the motor analogy has it's limits. The intake system is like a stove - it's powered by not-so-high external pressure. However, the exhaust system gases are powered by extremely high internal pressure - the explosion of burning fuel/air. And car exhaust has far greater volume compared to pipe cross section) . And we're talking about two vastly different scales of measurement because of those vast differences in pressure - even in the lower pressure intake side. So pipe resistance becomes FAR more critical in auto exhaust systems. Although, your welcome to try putting a set of Blackjacks on your stove and see if it shaves a few tenths off your reloading times.
As you, know, draft strength is effected in a big way by OAT's. At above freezing temps, both of my stoves run slowly enough naturally without the check damper being open, because of reduced draft strength of the warmer OAT.
However, at below zero temps it is like trying to hold back a blast furnace.
I only use the check damper when it gets down into the single digits and below. Above those temps, the primary and MPD do fine.
Now, back to when it warms up.
You have the option of using some amount of check damper opening when it gets warmer to help slow the stove. So do I, but then the range will still overheat the kitchen, so I do something else then.
I don't use the check damper in warmer weather because the range has so much heat extracting surface area - at least several square feet more than my #6. Unlike your stove, I have the option of closing off the water tank reservoir dampers and that reduces the heat radiating area of the entire right-hand 1/4 end of the range, while at the same time sending that heat to the chimney. That allows me to use less primary air and still maintain enough draft.
With the #6, the firebed has so much heat volume (BTUs) that it breaths fine though a mix of smaller bits and some fines. That allows me to run the stove slower like Lee does with his large firebed furnace while using up those small bits and fines - rather than throw them out as some stove owners do. There's lots of BTU's I paid for in that small stuff.
Paul
