Secondaries???

[scotsman]

Will someone please explain what these are and look like?

 

[begreen]

A search will get you more info than you can read in one night, with pictures and movies too.

 

[scotsman]

A search will get you more info than you can read in one night, with pictures and movies too.

Thanks for the info and the guidance.

 

[eyefish2]

secondary burn ==> this is the burn that takes place mostly in the upper part of the stove on non cat stoves. (not sure if cat stoves see this or not??) The primary burn takes place at and around the wood. The secondary burn takes place when you get the stove up to temp and you start closing off the primary air. The burning wood gases off and the gas burns in the upper part of the stove where the burn tubes introduce air. The secondary burn can be a roaring burn at the tubes if the wood is gasing off in a really hot stove. The secondary burn can also be a slower dancing burn that comes and goes with a relatively cooler stove.

 

[MF1529]

Your stove will most likely have a primary and secondary air intake. The primary is the one you can control and the secondary is a fixed intake that generally feeds the secondary tubes or plate in the top of your stove. The tubes or plate will have several small holes in them/it. When burning properly the tubes or plate will appear to burning like a gas grill burner. There will be orange and blue flame streaming out of the holes. This will be achieved when your stove is up to temp and the primary has been shut down. If it's burning properly there won't be much smoke coming out of your chimney. I posted a few pics of my stove last year in the link below. It's blury but one of the pictures shows the secondary burning.

https://www.hearth.com/talk/threads/71779/

 

[Ash_403]

Here is a decent short video. (not mine).

http://www.youtube.com/watch?v=K-hnKEbQbC0&feature=results_main&playnext=1&list=PL5698FC96568B4C76

 

[Wood Duck]

Yeah, as the previous guys said the secondaries are flames at the top of the stove burning wood gases and smoke released from the wood. The primary flame is also burning gases but it appears down at wood level. In a campfire you get mostly only primary flame, so the part of the burn that looks like a campfire is the primary. The secondary is all gravy made possible by the wonders of modern technology.

 

[scotsman]

Yeah, as the previous guys said the secondaries are flames at the top of the stove burning wood gases and smoke released from the wood. The primary flame is also burning gases but it appears down at wood level. In a campfire you get mostly only primary flame, so the part of the burn that looks like a campfire is the primary. The secondary is all gravy made possible by the wonders of modern technology.

Okay! Thanks! I've been getting those a lot, just didn't know what they were called. I get this bank of flame about 4-5" above the wood that extends across the stove. They are kinda like an aurora, blue with orange/yellow trim, and they are slower moving than flame "on" the wood. So, are these what you want to get before you try for the 12 hour burn? If so, what's next? Do you try to get no primary or secondary flame, a tiny bit or what? I understand that the Progress air can't be shut completely off. How do y'all do it to get it ready for an overnight burn? Thanks--

 

[Adios Pantalones]

I try for the best efficiency I can get with minimal primary air. The best indicator of efficiency is no smoke out the chimney. The secondary flames are an afterburner- burning the smoke.

For me this means- I want no smoke, but the primary air all the way closed if possible.

 

[Osburning]

http://www.youtube.com/watch?v=qvc79F1pR08&feature=related

 

[scotsman]

Okay, thanks for all the input. So . . . :
Are secondaries a good thing or not? Are they part of a progression to getting to a long, slow 12-hour burn or do I want to avoid them?

All y'all are apparently way more experienced than me and seem to understand how all this works. I'm still puzzling it out. Some say, put the wood in on a good ember bed, engage the cat and turn the air to minimum and leave it. Ron at Woodstock said he hadn't heard of that and wants to check it out, but the poster said someone at Woodstock had told him to do it and that it worked well. So, I'm confused.

So, will y'all experienced burners who have the Progress clue me in on what works for this machine? I just need a rough starting point so I can adjust from that. As you all know, I have the Progress, a lot of VERY old cedar rounds, a lot of dry hardwood pieces from a pallet manufacturer AND a damper installed just back of the stove on the horizontal connector pipe. All this is hooked to a 6" 25' SS, liner in a high wind environment with a STRONG draft 98% of the time, which is why Ron suggested the damper install.

Much obliged!

 

[corey21]

I don't really pay that much attention to the secondary's i find if i try for them i get a shorter burn. In my stove the secondary burn really chews threw the wood i look at how clean my glass is and the smoke coming from the chimney. I may be wrong but that's how i look at the secondary's i just let the baffle pick off what the primary burn missed.

 

[fire_man]

Okay, thanks for all the input. So . . . :
Are secondaries a good thing or not? Are they part of a progression to getting to a long, slow 12-hour burn or do I want to avoid them?

All y'all are apparently way more experienced than me and seem to understand how all this works. I'm still puzzling it out. Some say, put the wood in on a good ember bed, engage the cat and turn the air to minimum and leave it. Ron at Woodstock said he hadn't heard of that and wants to check it out, but the poster said someone at Woodstock had told him to do it and that it worked well. So, I'm confused.

So, will y'all experienced burners who have the Progress clue me in on what works for this machine? I just need a rough starting point so I can adjust from that. As you all know, I have the Progress, a lot of VERY old cedar rounds, a lot of dry hardwood pieces from a pallet manufacturer AND a damper installed just back of the stove on the horizontal connector pipe. All this is hooked to a 6" 25' SS, liner in a high wind environment with a STRONG draft 98% of the time, which is why Ron suggested the damper install.

Much obliged!

Terry:
Here is my take on those secondaries.

Secondaries are an unavoidable result of getting the firebox up high enough in temperature, so that the outgassing from wood "ignites", thus forming those twirly flamy guys above the wood. (Hey, I am starting to speak in Texan!)

Non catalytic stoves use this principle to get low emissions and more efficiency, they have a firebox which is well insulated and can reach higher temps so that the air spurting out from the burn tubes can iginite the smoke. Catalytic stoves do not have to reach such high firebox temps to burn efficiently, because the cat "lights off" at lower temps (500F instead of 1000F) and the cat burns the smoke at a lower temperature. Even with a cat stove, the firebox eventually reaches a critical temperature and you get secondaries (at least I always have with the Fireview).

Once the secondaries kick in, the firebox temp climbs even more, and it's hard to quiet them down.

Are secondaries a good thing?? Well, if you want lots of heat and an efficient burn, Yes. But if you want minimal heat and a very long burn time, then you want to keep them OFF for as long as possible. There are a couple ways to keep them off:

1. Reduce the air intake setting as low as possible.
2. Engage the cat at a very low firebox temp, but not so low that you stall the cat.
3. split your wood bigger (wider splits)

I kind of wonder if your ancient wood will outgas at a faster rate than those of using wood dated after 1000 BC. I suspect your secondaries may be more active and last longer than mine. The longest my secondaries lasted so far was 2.5 hours.

By the way, check your Iconel screen, it may have blown loose when you got that nuclear explosion earlier.

Hope this helps!

 

[begreen]

Secondaries are good, the fire is reburning un-burnt wood gas that would otherwise exit the flue as pollutants.

Grab some popcorn and a brew. Sit down and this video will explain much more than can be retyped here:

http://www.youtube.com/watch?v=qvc79F1pR08

not so good, but pretty:

http://www.youtube.com/watch?v=701ydLxZuMQ

and a helpful article:

http://www.brighthub.com/engineering/mechanical/articles/86002.aspx

 

[leeave96]

Okay, thanks for all the input. So . . . :
Are secondaries a good thing or not? Are they part of a progression to getting to a long, slow 12-hour burn or do I want to avoid them?

All y'all are apparently way more experienced than me and seem to understand how all this works. I'm still puzzling it out. Some say, put the wood in on a good ember bed, engage the cat and turn the air to minimum and leave it. Ron at Woodstock said he hadn't heard of that and wants to check it out, but the poster said someone at Woodstock had told him to do it and that it worked well. So, I'm confused.

So, will y'all experienced burners who have the Progress clue me in on what works for this machine? I just need a rough starting point so I can adjust from that. As you all know, I have the Progress, a lot of VERY old cedar rounds, a lot of dry hardwood pieces from a pallet manufacturer AND a damper installed just back of the stove on the horizontal connector pipe. All this is hooked to a 6" 25' SS, liner in a high wind environment with a STRONG draft 98% of the time, which is why Ron suggested the damper install.

Much obliged!

Secondaries are good. However, I don't own a PH so take my input with a grain of salt. I've got a cat stove (Woodstock Keystone) and a non-cat stove (Englander 30). Wood outgasses and that stuff needs to be burned - to reduce creosote output. Burning the outgas is also a great way to reclaim heat that would otherwise go out the chimney; therefore an EPA stoves generally burn less wood than their older smoke dragon ancestors. The cat lowers the temp of that burn from around 1000 degrees F to 500 degrees, hence you can get a low slow clean burn with a cat stove. The non-cat stove generally injects air at the top of the stove and with the firebox temp at 1000ish, the gasses will burn in the presence of secondary air. That cloud you see at the top of your stove are secondaries. That's good.

My view is you ought to run your stove in any manner that suits you - so long as you got no smoke out the chimney. If that means lots of secondaries and the heat that goes with it, OK. If that means, no flame in the firebox, only hot coals and a red hot cat for a low heat output - long slow burn - OK too.

My gauge to my stoves use are 1. How do I want to burn it and 2. No smoke out the chimney.

BTW, once the outgas stops, the secondaries and cat will dimish and go out and you are at a clean charcoal burn. That's good too. Your whole burn cycle will not consist of secondaries/cat glowing.

Enjoy the PH and post some pics!

Bill

 

[scotsman]

Terry:
Here is my take on those secondaries.

Secondaries are an unavoidable result of getting the firebox up high enough in temperature, so that the outgassing from wood "ignites", thus forming those twirly flamy guys above the wood. (Hey, I am starting to speak in Texan!)

Non catalytic stoves use this principle to get low emissions and more efficiency, they have a firebox which is well insulated and can reach higher temps so that the air spurting out from the burn tubes can iginite the smoke. Catalytic stoves do not have to reach such high firebox temps to burn efficiently, because the cat "lights off" at lower temps (500F instead of 1000F) and the cat burns the smoke at a lower temperature. Even with a cat stove, the firebox eventually reaches a critical temperature and you get secondaries (at least I always have with the Fireview).

Once the secondaries kick in, the firebox temp climbs even more, and it's hard to quiet them down.

Are secondaries a good thing?? Well, if you want lots of heat and an efficient burn, Yes. But if you want minimal heat and a very long burn time, then you want to keep them OFF for as long as possible. There are a couple ways to keep them off:

1. Reduce the air intake setting as low as possible.
2. Engage the cat at a very low firebox temp, but not so low that you stall the cat.
3. split your wood bigger (wider splits)

I kind of wonder if your ancient wood will outgas at a faster rate than those of using wood dated after 1000 BC. I suspect your secondaries may be more active and last longer than mine. The longest my secondaries lasted so far was 2.5 hours.

By the way, check your Iconel screen, it may have blown loose when you got that nuclear explosion earlier.

Hope this helps!

Oh HAR HAR, Tony! You've seen my wood--it IS old, but don't over-exagerate with that 1000 BC stuff when it's only about 800 BC! But, you're probably right and I've suspected that the low MC might be the cause of the gases going into secondaries for so long. Less moisture probably does something to the process, I'm just not smart enough to know what it is exactly and how to adjust for it.

I received a narrative from WS that I'm gonna try this weekend. I was trying to make the long burn happen on a single load of wood, but now see that it's a two-part process. That was what I wasn't understanding. So, tonight I'm setting it up to see how long I can maintain a decent temp in the great room, since it's supposed to be in the 30s and 40s for the next three days. I'm learning slowly, but surely.

I checked the screen. It's still in there. Looks okay, except it's in two pieces with a little gap between. Is that the way it's supposed to be? It's concave facing the air path.

I'm gonna try several different things y'all have suggested. My repertoire is expanding. I'll be doing custom burns in no time!

 

[HollowHill]

Oh HAR HAR, Tony! You've seen my wood--it IS old, but don't over-exagerate with that 1000 BC stuff when it's only about 800 BC! But, you're probably right and I've suspected that the low MC might be the cause of the gases going into secondaries for so long. Less moisture probably does something to the process, I'm just not smart enough to know what it is exactly and how to adjust for it.

I received a narrative from WS that I'm gonna try this weekend. I was trying to make the long burn happen on a single load of wood, but now see that it's a two-part process. That was what I wasn't understanding. So, tonight I'm setting it up to see how long I can maintain a decent temp in the great room, since it's supposed to be in the 30s and 40s for the next three days. I'm learning slowly, but surely.

I checked the screen. It's still in there. Looks okay, except it's in two pieces with a little gap between. Is that the way it's supposed to be? It's concave facing the air path.

I'm gonna try several different things y'all have suggested. My repertoire is expanding. I'll be doing custom burns in no time!

Terry, Fellow Progress owner (and newbie to wood burning) here. If you wouldn't mind sharing the WS narrative on the long burns, I'd sure appreciate it. Thanks!