Flames Going Into Air Intake

[Woodcutter Tom]

I have a small Pleasant Hearth WS2417 stove. It has an air wash design for keeping the glass clean. The primary air enters the fire box from above the glass in the door. It is suppose to flow down over the glass keeping it clean.

On occasions, I see flames going up into the area where the primary air enters the fire box. Is there any significance to this?

I also see flames going up into the area where the exhaust leaves the firebox. I attribute that to the draft sucking the flames up.

Both of these can happen at the same time.

I'd appreciate thoughts.

 

[moresnow]

Completely normal secondary combustion occurring at the top of the fire box. Actually ideal.

 

[spudman99]

Perfectly fine. Oxygen is a fuel source for a fire. Thus the fire chases the fuel, hence rising up to the air intake. Draft pulls the existing flame towards the exhaust, also normal. That helps to keep the flue temperatures above 220deg which helps to retard the accumulation of creosote on the liner itself. Worry not unless the firebox is completely engulfed and you cannot control the flames via the intake.

 

[Woodcutter Tom]

Thanks guys for the replies.

I had wondered if this might be an indication of poor draft. My thought was that the draft is not strong enough to pull the primary intake air down along the glass, thus the flame is 'attracted' to the fuel source as soon as it enters the firebox. If the air was moving quicker, the flame would not flow up into the intake area.
I also think I read that the primary intake air flows down the glass because it is cooler than the air in the firebox, so air flow speed may not be the cause.

I try to look at all factors as I try to get my stove to perform to it's capabilities.

 

[Mech e]

Perfectly fine. Oxygen is a fuel source for a fire. Thus the fire chases the fuel, hence rising up to the air intake. Draft pulls the existing flame towards the exhaust, also normal. That helps to keep the flue temperatures above 220deg which helps to retard the accumulation of creosote on the liner itself. Worry not unless the firebox is completely engulfed and you cannot control the flames via the intake.

Three things are required for fire to exist: fuel, heat, and oxygen. Remove any one of the three and the fire goes out. In this case, the fuel is the particles in the smoke. The secondaries are replenishing the supply of oxygen needed for fire.

 

[firefighterjake]

Three things are required for fire to exist: fuel, heat, and oxygen. Remove any one of the three and the fire goes out. In this case, the fuel is the particles in the smoke. The secondaries are replenishing the supply of oxygen needed for fire.

But don't forget about the chemical reaction occurring between the three . . . if you break the chemical reaction the fire will also go out. Not that this has any bearing to the discussion at hand though.

 

[Manly]

Three things are required for fire to exist: fuel, heat, and oxygen. Remove any one of the three and the fire goes out. In this case, the fuel is the particles in the smoke. The secondaries are replenishing the supply of oxygen needed for fire.

Thank you for shedding light on a phenomenon that has baffled me for far too long.