Importance of Over Fire Air & Blue Flames

Re: Importance of Over Fire Air & Blue Flames

PostBy: dcrane On: Wed Nov 13, 2013 10:07 pm

franco b wrote:This link worked.
http://www.youtube.com/watch?v=ATr1irbj ... e=youtu.be

Good job.


TY Franco... my very first attempt at a video :clap: (I forgot to put a link to nepacrossroads :cry: ) ... that's OK, that was just a fast one for the thread, ill get some better ones when im pro.
dcrane
 
Hand Fed Coal Stove: Crane 404

Re: Importance of Over Fire Air & Blue Flames

PostBy: 2001Sierra On: Wed Nov 13, 2013 10:30 pm

I don't have any Hollywood Videos like the rest of you :roll: but I can tell you how my old Buderus 3115 provided secondary combustion air.The glass was segmented and along the bottom edge of the glass retainer there where slots cut in the steel allowing air to wash up the glass. Also on the left there was a opening about the size of my Busch beer can opening with a door that could be adjusted. Blue ladies where very consistent with fresh load of coal, and then as the coal came into the burn area from the above hopper the distillation of the coal gases would take place and be burned off.
2001Sierra
 
Hot Air Coal Stoker Stove: Keystoker 90 Chimney vent
Coal Size/Type: Rice
Other Heating: Buderus Oil Boiler 3115-34
Stove/Furnace Model: Keystoker 90 Chimney Vent

Re: Importance of Over Fire Air & Blue Flames

PostBy: rberq On: Wed Nov 13, 2013 11:10 pm

Rob R. wrote:It is a delicate balance to admit enough air over the fire to properly burn off the volatiles and CO, while not sending excessive amounts of heat up the chimney

Lightning wrote:I've considered constructing a secondary air distribution system like you described with piping and drilled holes running the perimeter of the five box

wsherrick wrote:It might be possible to make something for other stoves that is similar to that in the Glenwood. I wonder if a heavy duty steel pipe, bent to go around the top of the fire pot with holes drilled in it might be fairly easy to adapt. One would need the proper calculations about what is the proper amount of air to be admitted would be.

Admit enough secondary over-the-fire air to get the blue flames burning. Use an automobile oxygen sensor in the stove pipe to detect how much excess oxygen (excess air) is being admitted. Then adjust the secondary air control so the excess is as close to zero as possible. I suggested this once before, and somebody told me why it wouldn’t work, but I have forgotten why so it seems like a good idea again. :P
rberq
 
Hand Fed Coal Stove: DS Machine 1300
Coal Size/Type: Nut -- Kimmel/Blaschak/Reading
Other Heating: Oil hot water radiators, propane

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Re: Importance of Over Fire Air & Blue Flames

PostBy: Lightning On: Thu Nov 14, 2013 4:13 am

SO I'm curious as to what I'm looking at here (yes its burning coal :lol: ).. In this pic (remember, at first glance this apperared to be a cold smoldering fire till I cranked up the camera exposure time) my thinking is that these flames are from carbon combusting into CO2 and CO.
View: New PagePopup



Then in this pic, with the addition of secondary air, the bright blues seem to form up over the little blues in the picture above. These would be CO combusting into CO2?
View: New PagePopup


At this point it's a tough call.
Could the secondary burn yield more output? Or is the extra nitrogen that's added carrying That little bit of extra heat out the chimney. I believe this is where the antiques shine. They possess the extra hardware to extract that heat into the home. Although in my opinion, it may only be a few percent. Where for us with the modern box stoves it's more for viewing pleasure.

Opinions and results may vary, headaches can also occur
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Importance of Over Fire Air & Blue Flames

PostBy: Stanb999 On: Thu Nov 14, 2013 9:18 am

Lightning wrote:SO I'm curious as to what I'm looking at here (yes its burning coal :lol: ).. In this pic (remember, at first glance this apperared to be a cold smoldering fire till I cranked up the camera exposure time) my thinking is that these flames are from carbon combusting into CO2 and CO.
View: New PagePopup



Then in this pic, with the addition of secondary air, the bright blues seem to form up over the little blues in the picture above. These would be CO combusting into CO2?
View: New PagePopup


At this point it's a tough call.
Could the secondary burn yield more output? Or is the extra nitrogen that's added carrying That little bit of extra heat out the chimney. I believe this is where the antiques shine. They possess the extra hardware to extract that heat into the home. Although in my opinion, it may only be a few percent. Where for us with the modern box stoves it's more for viewing pleasure.

Opinions and results may vary, headaches can also occur



Those pictures right there are why most manufacturers have gone to non adjustable overfire air. It gives more btu's and for most of us it seems counter intuitive that it would. So We would block them. Fully if possible. :lol:

Neat to see the flames in the "cold" fire too. I learned about "dark" flame from working with wood stoves that had secondary burners. The stove would be dark except for near the charcoal. But the stainless steel pipes at the top of the burn chamber would be cherry red with the orifice holes looking white hot. That happens at very high temps so flame was present. But no flame "light" was visible.
Stanb999
 
Stove/Furnace Make: Harmon
Stove/Furnace Model: Mark II

Re: Importance of Over Fire Air & Blue Flames

PostBy: KingCoal On: Thu Nov 14, 2013 10:31 am

Stanb999 wrote:
Lightning wrote:SO I'm curious as to what I'm looking at here (yes its burning coal :lol: ).. In this pic (remember, at first glance this apperared to be a cold smoldering fire till I cranked up the camera exposure time) my thinking is that these flames are from carbon combusting into CO2 and CO.
View: New PagePopup



Then in this pic, with the addition of secondary air, the bright blues seem to form up over the little blues in the picture above. These would be CO combusting into CO2?
View: New PagePopup


At this point it's a tough call.
Could the secondary burn yield more output? Or is the extra nitrogen that's added carrying That little bit of extra heat out the chimney. I believe this is where the antiques shine. They possess the extra hardware to extract that heat into the home. Although in my opinion, it may only be a few percent. Where for us with the modern box stoves it's more for viewing pleasure.

Opinions and results may vary, headaches can also occur



Those pictures right there are why most manufacturers have gone to non adjustable overfire air. It gives more btu's and for most of us it seems counter intuitive that it would. So We would block them. Fully if possible. :lol:

Neat to see the flames in the "cold" fire too. I learned about "dark" flame from working with wood stoves that had secondary burners. The stove would be dark except for near the charcoal. But the stainless steel pipes at the top of the burn chamber would be cherry red with the orifice holes looking white hot. That happens at very high temps so flame was present. But no flame "light" was visible.


yep, i've found that i can in fact close down the non adjustable secondaries on my DSM 1400 but it increased draw thru the bed and increased the flames as well. so no net gain for my system.

absolute control of over fire draft is much more effective. over draft combined with fixed secondaries causes heat loss big time. for my installation it's a tight balancing act.
KingCoal
 
Hand Fed Coal Stove: DSM 1400, Riteway # 37, Comforter Stove Works
Coal Size/Type: Nut Anth.
Other Heating: none
Stove/Furnace Model: 2013 1400 Circulator

Re: Importance of Over Fire Air & Blue Flames

PostBy: Lightning On: Sat Nov 16, 2013 7:49 am

I have some interesting numbers to share this morning. Earlier this morning, my furnace holding steady at 228 degrees over the load door and 153 on the pipe with -.0275 on the mano, secondary air at 50%. I then opened the secondary to 100%.

Now, three hours later, I see an increase of 13 degrees over the load door and 12 degrees on the pipe with mano reading a frog hair under -.03.

Is all of that increase due to burning CO over the coal bed? Probably not. My speculation is that some of it is. Some also from a frog hair's worth of added primary due to draft increase.

I also suspect that some secondary air sinks into the top layer of the coal bed aiding in direct combustion of coal.

I could also throw in that the extra nitrogen is carrying heat around promoting heat transfer that would otherwise just sit in the coal bed :lol:

I dunno what to make of it. Probably a small contribution of all of those hahaha.
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Importance of Over Fire Air & Blue Flames

PostBy: KingCoal On: Sat Nov 16, 2013 8:21 am

i support your conclusions.

now that i'm running steady with MPD closed, the mano. averaging .325 - .037 and the fixed secondaries doing what ever it is that they contribute, i have much better retention and radiation of heat.

blues never leave they top of the bed, even just before a tending they're an 1/2" tall and pretty much every where. this could be tied to the fact that it's warmer and i'm running coal in over the bed by hand, no coal in the hopper though.
KingCoal
 
Hand Fed Coal Stove: DSM 1400, Riteway # 37, Comforter Stove Works
Coal Size/Type: Nut Anth.
Other Heating: none
Stove/Furnace Model: 2013 1400 Circulator

Re: Importance of Over Fire Air & Blue Flames

PostBy: Lightning On: Sat Nov 16, 2013 9:04 am

Why aren't you using the hopper?

Continued increase with secondary at 100%. Total of 18 degree increase over the load door and 24 on the pipe. No change on the mano. Total of 5 hours since I opened the secondary.

Further observation today I expect will be skewed by draft decrease as it warms up outside :(
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Importance of Over Fire Air & Blue Flames

PostBy: KingCoal On: Sat Nov 16, 2013 10:04 am

in warm weather ( http://www.wunderground.com/cgi-bin/fin ... uery=46528 ) the hopper on this stove is just redundant. i'm putting 9 #'s of coal in it every 12 hrs or waiting and putting 18 #'s in at 24.

if i don't create a strategy of things "I" need to do i'll have to get involved in another chapter of the "honey do" BOOK. :mad:

she'll be out shopping with the grandson when i get home so............. i'll be doing some more damper experimenting. :lol:
KingCoal
 
Hand Fed Coal Stove: DSM 1400, Riteway # 37, Comforter Stove Works
Coal Size/Type: Nut Anth.
Other Heating: none
Stove/Furnace Model: 2013 1400 Circulator

Re: Importance of Over Fire Air & Blue Flames

PostBy: Stanb999 On: Sat Nov 16, 2013 10:43 am

Lightning wrote:
Further observation today I expect will be skewed by draft decrease as it warms up outside :(



Only on the coal forum are people upset it's going to be a warm sunny day! :lol: :lol: :lol:
Stanb999
 
Stove/Furnace Make: Harmon
Stove/Furnace Model: Mark II

Re: Importance of Over Fire Air & Blue Flames

PostBy: Lightning On: Sat Nov 16, 2013 10:49 am

Cool man! 8-)

The effects of the secondary has leveled off. Wish I was home to see what's going on in the fire box though :ugeek:
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Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

Re: Importance of Over Fire Air & Blue Flames

PostBy: Lightning On: Sat Nov 16, 2013 11:13 am

Stanb999 wrote:
Lightning wrote:
Further observation today I expect will be skewed by draft decrease as it warms up outside :(



Only on the coal forum are people upset it's going to be a warm sunny day! :lol: :lol: :lol:


Oh I know, right? Actually I got the primary cut back for a 24 hour burn. I hope to get home in time to put away the rest of the lawn furniture :lol:
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut/Stove Size Mix

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