Base Burner Question

Lightning wrote:

Sunny Boy wrote:And, he had been using wood in it, for whatever difference that might make.

And that is just heat from the flue gases, correct?
Would any infrared radiation from the fire bed contribute to that directly?

Yes, just flue gases.

Radiation? The ash drawer level separates the firebed level from the base flue level.

When in indirect mode, think of the base heater as kinda like a house. The base flues are in the basement. The ash drawer is the first floor, the firepot is the second floor, and the barrel is the stove's attic.

However, unlike most houses, the only way you can get to the basement is to use the "fire escape" (back pipe) from the attic. There's no access from the first, or second floors directly to the basement !

Does that help, or did I just add to the confusion ?

Paul

This January when we can crank them up lets talk internal temps along with skin temps and all discussion ended once and for all time.

Lightning wrote:

Sunny Boy wrote:And, he had been using wood in it, for whatever difference that might make.

And that is just heat from the flue gases, correct?
Would any infrared radiation from the fire bed contribute to that directly?

i don't think that is quite correct. the fire pot on the #6 and #8's are directly mounted to the ash and base chamber casting. heat generated in and by the fire pot is being released and absorbed into all that structure AND the exhaust circulation is contributing even more.

my new stove is built and will function the same way.

steve

The base chamber is the last place the flue gases pass on the stove, correct? Then they exit thru the stove pipe?

You proud base burner guys never measured the base to see how effective it is?

You guys are Killin me

Lightning wrote:The base chamber is the last place the flue gases pass on the stove, correct? Then they exit thru the stove pipe?

well, not quite on that also. on the 6 and 8 there is a bit of a caboose or dog house compartment that absorbs and radiates more of the last of the heat from the gasses in the final exit channels.

some of the other , internal by pass type, base burners also have the double heater path way traveling up the back of the stove between the combustion chamber and the exhaust channel for much the same purpose.

KingCoal wrote:

Lightning wrote:The base chamber is the last place the flue gases pass on the stove, correct? Then they exit thru the stove pipe?

well, not quite on that also. on the 6 and 8 there is a bit of a caboose or dog house compartment that absorbs and radiates more of the last of the heat from the gasses in the final exit channels.

some of the other , internal by pass type, base burners also have the double heater path way traveling up the back of the stove between the combustion chamber and the exhaust channel for much the same purpose.

IMHO most of this was practicable and in fact only made possible by the then current very advanced casting arts.

Please enough of the overblown BS. I have a very close friend that can cast at 1mm .0400 in round number and if you think they could do it then you are in fantasy world. They are complex shapes and not a box or square either. !905 is not the pinnacle of casting it is today.

fixed it for ya. carry on.

KingCoal wrote:
the fire pot on the #6 and #8's are directly mounted to the ash and base chamber casting. heat generated in and by the fire pot is being released and absorbed into all that structure AND the exhaust circulation is contributing even more.

my new stove is built and will function the same way.

steve

So your thinking is that the heating of the base chamber is also by way of radiation absorbed and radiated thru the layers between the fuel bed and the base.

And then also by way of conduction of heat around the outside of the stove along with contribution of the flue gases.

Thanks for everyone's input, I'm just trying to get a grip on how these stoves do their thing.

Lightning wrote:

KingCoal wrote:
the fire pot on the #6 and #8's are directly mounted to the ash and base chamber casting. heat generated in and by the fire pot is being released and absorbed into all that structure AND the exhaust circulation is contributing even more.

my new stove is built and will function the same way.

steve

So your thinking is that the heating of the base chamber is also by way of radiation absorbed and radiated thru the layers between the fuel bed and the base.

And then also by way of conduction of heat around the outside of the stove along with contribution of the flue gases.

Thanks for everyone's input, I'm just trying to get a grip on how these stoves do their thing.

Lee,
Basically, by adding a base chamber to the flue gas pathway,...
1. The chamber and the flues leading to and from that chamber, greatly increase the heat radiating surface area with the same floor "foot print" as other stoves of like-sized firepot.
2. The longer internal flue pathways help naturally slow down the flue gas speed through the stove by resistance to flow and by lowering the flue gas temps before they get to the chimney. That gives the flue gases more time to transfer their heat before reaching the chimney. And that's done without having to use warmed room air bled into the flue gas stream at the stove pipe - such as with a baro - to retard draft strength .
3. The base chamber heats the floor around the stove and lower area of the stove thus starting to distribute it's heat at lower points in the room.
4. By keeping the ash drawer area hotter, it preheats the incoming primary air to a higher temp than other types of stoves can, thus helping to give more complete combustion of the coal. That's one of the reasons why so many base heaters and base burners can turn out white powder ash while not having the firebed burning so hot to get the same heat output that makes chunky ash with clinkers in non-base heater stoves.
My range is a base heater, by having the flues lead around and under the oven adding about 10-12 feet of flue gas travel inside the range. However, while it's terrific at extracting heat before the stove pipe, those flues don't extend under the ash drawer area. By missing that part of a true base heater, my range can't burn coal as compleatly to a white powder the way a base heater can.

Anytime you burn a fuel, preheating the incoming air as much as possible, before it reaches to the firebed, helps increase burn efficiency. Wood stoves have been doing that for many years as one of the ways to help meet EPA regs for clean burning.

Paul

Something not mentioned much at all besides the longer exhaust paths with their added square feet of surface area for exposure is the additional benefit of "massaging" the gases at each and every turn or bend along through the maze to exit.
On any stove with little or no turns, but... equally long exhaust paths and with equal square feet of surface area the same heat cannot be extracted.
Shielded heat in the stream must be "massaged" out of the gas stream, if you will, continual, gentle turbulence as the gases follow the winding pathways.

Please feel free to comment if I've poorly stated this.

Really good explanations by Paul and McGiever.

All I would add is that in the base burner there will be less flue gas volume per pound of coal burned.This is because the round brick lined fire pot along with the hotter primary air mentioned by Paul mixes more thoroughly with the coal, which means less CO and less excess air. That in turn means less volume and velocity to the flue gas making heat exchange more efficient.

Yes, Franco, as you pointed out before, one more reason my rectangular fire box can't compete with a true base heater/base burner for burn efficiency - corners don't burn coal as well as the rest of the fire bed.

And, those corners don't clear ash quite as completely during shaking as a round firepot does - sometimes requiring a bit of poking from below.

Paul

McGiever wrote:Something not mentioned much at all besides the longer exhaust paths with their added square feet of surface area for exposure is the additional benefit of "massaging" the gases at each and every turn or bend along through the maze to exit.
On any stove with little or no turns, but... equally long exhaust paths and with equal square feet of surface area the same heat cannot be extracted.
Shielded heat in the stream must be "massaged" out of the gas stream, if you will, continual, gentle turbulence as the gases follow the winding pathways.

Please feel free to comment if I've poorly stated this.

Very clearly stated -I know exactly what you mean, Mac.

Paul

I tend to agree with that McG. Seems some turbulence would help extract heat. You may have heard me mention of "reverse wind chill effect". The tumbling flue gases would tend to give up heat more thoroughly I think.