My new load door window is coming in handy!
I tried some pictures thru it today in an attempt to demonstrate different reactions to the fire with secondary air. SO, with that lets start the show lol..
My secondary air comes in thru a port on the back of the furnace about 6 inches over the top of the coal bed. Being cooler than the air in the fire box, it sinks and flows across the top of the coal bed.
1.... This is after loading and immediately after I've closed the ash pan door and load door (for volatile bake off) about 45 minutes after loading.. Secondary air is open.. (8 second exposure)
2.... Same conditions as above, except now secondary is closed..
The blues seem to be starving and following the camera exposure, the blues were lost.
As soon as the blues were lost, I opened the secondary again to let them reignite.
3.... About an hour later, I checked the fire again and there were still some blues over the fire bed. Then, I closed the secondary, the blues went away and this is what I saw. It looks like a cold smoldering coal fire doesn't it??
4.... Heres the really neat part.. I shut the lights off in the basement. Its pitch dark down there. Within several minutes my eyes adjust to the darkness and I notice a soft blue hue in the fire box.. I set the exposure on the camera for the shutter to be open for 15 seconds (Its on a tripod for longer exposure times)..
This is the same fire as the one above.. Can you believe it??!!
5.... Now, lets do that again with the secondary open.
SO what does this all mean? I don't know
But seems like a little secondary air is helpful for completing combustion a little better.