Secondary combustion

[bokehman]

What does your secondary burn look like (flame colour, density, etc). I've seen a couple of movies on youTube and I don't see anything like that inside my insert.

I've got two types of flames: dense orange ones that burn on the wood and look fuel rich and blue phantoms that appear for a few seconds every so often in mid air between the wood and the deflector plate. I never see any sort of sustained burn at the top of the firebox. Am I doing something wrong?

Also the phantoms disappear if I open the primary or when new wood is added.

I haven't got a thermometer but I know the stove is hot because the secondary air tubes are glowing dull red.

 

[jtp10181]

Usually you get more secondary I think if you get the wood nice and charred then choke the air down. Then it will start burning on the top near the tubes and the flames coming off the logs will die down or go away. This is what I see on the 7100FP when I test them out at customers houses.

 

[Sandor]

The blue flames burning in mid air is your secondary combustion.

 

[Lignums]

On my 2 year seasoned Red Oak, a blue flame snakes across the top of the baffle and air tubes. It occasionally licks the wood, but for the most part it hangs out in the middle/top of the stove.

 

[bokehman]

Usually you get more secondary I think if you get the wood nice and charred then choke the air down. Then it will start burning on the top near the tubes and the flames coming off the logs will die down or go away.

Could I be leaving the primary open too long? Even with the primary completely close there is lots of flame.

On my 2 year seasoned Red Oak, a blue flame snakes across the top of the baffle and air tubes.

Reading between the lines, does that mean if the wood is not that well seasoned there won't be secondary combustion?

At what stage in the burn cycle is the secondary combustion strongest?

 

[Shipper50]

I have 4 burn tubes in my Regency I3100 and only the back one seems to burn blueish when I get a good fire going. I see orange flames coming off the wood, but the other 3 tubes don't seem to be burning. I am burning shag bark hickory for wood.

If your getting your tubes to glow, then you got me beat all to he00....

Shipper

 

[n6crv]

The flames coming down from the top are my secondary burn.

 

[jtp10181]

bokehman, with the air closed down the flames should nearly die out. I would check all gasketing and opening in the unit for air leaks. Close a dollar bill in the door in various places and make sure you get some resistance when pulling it out. If there is little or no resistance you may need to tighten the door latch or replace the gasket. It sounds to me like you have an air leak someplace.

Also, how tall is your chimney and what kind of pipe is it. According to your signature it looks like you have a built in unit, do you know if it meets EPA regs?

 

[Lignums]

As long as you can see some flame that does not appear to have anything to do with the wood you have it going on. The flames seem be be a little longer than they should be. In the right conditions, it will hang out all by itself, but mostly, in my stove, a flame will 'leak' upwards, and then there will be a roll of flame from the back of the stove, to the front. It takes a hot stove to make this happen also. It takes heat to make heat. The Oak makes a blue flame, and I have not gotten to the Black Locust as of yet, still a cord of Oak to go.

 

[bokehman]

I would check all gasketing and opening in the unit for air leaks. Close a dollar bill in the door in various places and make sure you get some resistance when pulling it out. If there is little or no resistance you may need to tighten the door latch or replace the gasket. It sounds to me like you have an air leak someplace.

We don't have dollar bills here. The unit is new so the gasket should be good but I'll give it a try. Certainly can't choke out the primary combustion with the air on minimum.

Also, how tall is your chimney and what kind of pipe is it. According to your signature it looks like you have a built in unit, do you know if it meets EPA regs?

chimney is 5.5 metres. The manual says between 5 and 6. Has a stainless stovepipe. Not sure about EPA. If the unit is not offered for sale in the US it wouldn't need to be EPA tested even if it could pass the test just fine.

 

[jtp10181]

Hmmm... well since that unit might not be made to the same standards as here it might burn differently. Its possible when you close the air down all the way it is letting in more air than the stoves in the USA do when closed down. Looking at the pictures and manual it looks very similar to what is sold here so I imagine it puts out some good heat.

Sometimes on new units the door latch needs to be adjusted after a few fire because the gasketing shrinks.

Do you know about how tall the chimney is, the height. You could be getting too much draft as well.

 

[DiscoInferno]

On mine secondary burn is completely obvious, it looks like an upside-down gas burner with flame appearing to shoot out of all the holes in all 4 tubes. (Really it's just the air coming out of the tubes, of course.) If the primary is closed then that's mostly the only flame in the firebox.

 

[bokehman]

Sometimes on new units the door latch needs to be adjusted after a few fire because the gasketing shrinks.

Ok, I used a 50 Euro note which I'm guessing is probably similar thickness. Depending where I put it I either can't move it or can pull it out but with lots of resistance.

Do you know about how tall the chimney is, the height. You could be getting too much draft as well.

5.5 metres or 18 feet to you. Manual recomends between 5 and 6 metres (16.25' - 19.5').

 

[jtp10181]

Sorry about the height thing, when you said 5.5 I was thinking that was the diameter of the liner, since they sell 5.5 inch diameter liners here.

Well without knowing more about that unit all I can say is maybe that's how its supposed to burn?

 

[bokehman]

Maybe this is nonsense but I was thinking:

There are two sources of air, primary and secondary, what stops the secondary air providing oxygen for primary combustion if the firebox is full nearly to the top?

 

[jtp10181]

nothing on most stove, but it is a limited amount of air that it lets in. So normally you can still control the burn with the primary air adjustment.

 

[jbrown56]

Hi, To get secondary burn in my stove I first get the stove temp close to 500*, then close the damper down to 1/4. That will produce a flame that rolls in the top of the stove that resembles " tumbleweed in a clothes dryer ". It will last for 10 - 15 min. and then will settle into secondary burn with blue and dark orange flames on top of the charred wood. Ths will last from 1 - 2 hrs. and at that point I will damper down all the way and it will last 8 - 9 hrs. I think the length of the secondary burn depends on the density of the wood. Hope this helps.

Jim

 

[bokehman]

Could the problem be the fuel? I've found that when I get the unit nice and hot if I throw in a sheet of cardboard the secondary comes to life in a way I've never seen before.

 

[mikeathens]

Ok, I used a 50 Euro note which I'm guessing is probably similar thickness.

HAHAHA...I can't help but laugh. I can't imagine checking gaskets with a $100 bill. I'm literally laughing out loud. Thanks, I needed that...

 

[bokehman]

HAHAHA...I can't help but laugh. I can't imagine checking gaskets with a $100 bill. I'm literally laughing out loud. Thanks, I needed that...

Well we don't have notes as small as 1 dollar. Smallest note here is 5 Euros and the largest in natural circulation is 500 Euros. The 500 notes are known as Bin Ladens because everyone claims not to know where they are even though there are more of them in this country than any other country in Europe (probably due to the black economy).

 

[jtp10181]

Could the problem be the fuel? I've found that when I get the unit nice and hot if I throw in a sheet of cardboard the secondary comes to life in a way I've never seen before.

Yeah if your wood has too much moisture in it the gases coming off might not be hot enough to create secondary combustion. Do you get a lot of smoke out of the stack when burning?

 

[bokehman]

Do you get a lot of smoke out of the stack when burning?

I get some when I load it but not lots. Also seems to need a lot of air to get the wood to the point where it will continue burning with the primary closed.

The wood is supposed to have been split about one year (looking at the wood I believe it). It's semi-desert here with nominal humidity about 35%.

But the pile at the wood yard is not covered and it rained a few times in December. Seems dry though.