Real Puffback

Last thirsday afternoon I experienced my first real puffback,luckely there is nothing damaged.
later I realised I made all of the classical mistakes, witch give you in return a nice small explosion in the stove.
I was in a hurry, so loaded to much coal in a short time, ofcourse covering all the fire, and went away doing things before leave the house.
But because I am a little stupid, or in a hurry again,friday morning I did it again.
I was loading the stove with a serious amount of coal to let it burn for several hours. loading again to much, to fast,
take just a little more time to look if it was going well.
Saw that smoking pile started thinking when I open the door crack giving some over fire air that helps burning the gasses.
And it works, close the door and the gasses stopped burning
Wait a while, the pile is stil smoking, I think I do the trick again, open the door slowley.
Trick doesn't work
Sat down on the couch just a little waiting and ......WOOOSH that was the second one
It was a nice fireball in the ash pan.
Saturday morning, tending the stove and again to much...... and so on and what do you guesh,
No this time I had a better idea, I toke my poker opend the door just enough for let the poker trough, punched a little hole in the pile on a spot where I saw a little glowing coal and poof a small flame came out I closed the door and the flame ignited the gasses fast but without a explosion.
Remember this is my second burning season, wich started last year halfway.
So some days of a hasty coal burner.
But still love it.

Thats funny, it sounds similar to my experience. Becuase of the wild swings in temp I've been struggling to keep mine running this year.

Just Peter, I prop my load door open about a quarter inch for about 20 minutes after adding fresh. During that 20 minutes I make coffee, take a shower or whatever before work and by the time I get back to it its all happy little blue ladies and I can close her up tight. I'm still developing a morning routine. Thats what I've came up with so far

Thank you for the advise.
But the embarrising point wasthat I read the whole hand fired coal stoves department, and seen lot of the same questions, also I read the sticky about the minor explosion, and still I have to experience it in real life
Well still going on climbing the learning curve.

Peter.

We all learn best by our own experiences.. You should have seen the 'puffback' that I had from loading 70# of Bit coal on a hot fire, closed the door to the boiler, [in an outdoor building] I was walking back to the house when a huge cloud of black smoke bilowed out of the chimney, I walked back in and found the 14'x22' building solid black inside, soot everywhere even on the underside of the ceiling.
The inside volume of this boiler is huge, so the 'puffback' was more of an explosion. it blew the flue pipe apart at the swivel joint elbows .

I had to powerwash the inside of the building the next summer to clean the soot off the ceiling.'

Thankfully most of our residential stoves don't have that large of an air volume, so we get 'puffbacks', not explosions.

Greg L

Greg, was that caused by Big Bertha, or the AA260 (or are they one and the same boiler)?

just peter wrote:Thank you for the advise.
But the embarrising point wasthat I read the whole hand fired coal stoves department, and seen lot of the same questions, also I read the sticky about the minor explosion, and still I have to experience it in real life
Well still going on climbing the learning curve.

Peter.

Welcome to the "Yeah I read all that but still had to have my own puffback" club!!!

Nothing like a little "WHOOSH" to get the juices flowing!

Well, all I'm going to say is......the alarm monitoring company calls me really quickly............

lsayre wrote:Greg, was that caused by Big Bertha, or the AA260 (or are they one and the same boiler)?

It was Big Bertha, the big handfed boiler I built.
the air volume inside this BIG handfed is about the size of a small refrigerator so there was a lot of gas to explode.

The AA260 only holds about two 5 gallon buckets of air volume. That ignited is just a puffback.

Greg L

Greg, how do you do to load the big one?

I don't run Big Bertha anymore, she's sitting with warm water circulating through her, so she won't freeze.
I'll find some old photos.
Big Bertha is a huge boiler that I made to burn wood, with a tripple pass heat absorber/exchanger, all of it easily accessable so creosote could be scraped off the inside.
The boiler is made entirely from 409 stainless Steel, it's a work of industrial art.
But once I started feeding it with enough wood to make the BTU's I need to heat the place, I realized that I really needed a different fuel, that had more BTUs and lasted longer.

So I tried some local Bit coal I located, and it was nasty stuff, but it lead me to learn more, and that led to this forum.
I modified the firebox to make it burn coal better, and hand fed it with stove and nut Bit and Anthracite.. But
I still needed a more consistant fire, the hand feeding process was too demanding of my time, and still too labor intensive

Then I found an Iron fireman Bit stoker, and figured out how to make it work in Big Bertha. With this stoker I could load
two days worth of coal into the hopper and just empty the ash pan daily..

Then I found the AA 260, bought it and rebuilt it, it 's capable of a lot more BTU's and has a much more efficient heat
exchanger design, a larger ash pan and I made a hopper good for one week's worth of coal.

Big Bertha has a very large loading door, 20"x24", I made it very large so I could easily load large , long logs. I was not aware
the dificulty of loading so much wood to keep the beast filled and making the amount of BTU's I needed.

I loaded coal into big bertha with a five gallon bucket, I dumped two buckets of coal in the firebox every 8-10 hours. That's
about 30-35# per bucket.

Greg L

I once again go against the grain on this one as well. I never leave an open spot of burning coal. When I am reloading the stove I am loading in a lot of coal. When I burned my Chubby, I would overfill the pot and load in almost thirty pounds of coal. With the Jotul's I never leave a spot of burning coal and I fill them to the top as well. I do however run with a small over the fire draft for the first half hour after loading the stove. With the Chubby I ran with a constant over the fire draft, not a lot, just a very small amount. The small constant influx of over the fire draft after reloading saves my bacon in the puff back arena. If I ever forget to come back and close the over the fire draft, it isn't going to hurt the stove. Since every stove setup is different, my system of reloading and such may or may not cause a puff back of varying size in another stove or setup. For me this is how I do it.

The snowman.

I nearly jumped off my couch last night! Heard a big WHOOSH. Went to check on the stove and all was well. I've had a few minor puffbacks in my Chubby, but last nights startled me. I usually load the stove to the top of the firepot without any issues. As crazy as this sounds, it's neat to see that blue fireball! Only happens shortly after reloading. I crack open my overfire vents until I get a steady blue flame across the fire, seems to help. Live and learn!

Since I have a small oval burn pot, it's impossible to load the stove and leave it banked.

I've experienced several puffbacks. The first one was severe, popping the two lids off, blowing dust out of every fixture, etc. Since then I never load coal before I leave in the morning. I have no over the fire vents, so I crack the top lid just a whisker and it seems to do the trick.

As has been said, evryone has a different setup. Even if you have the same same stove, no two exhausts are the same. I've learned a lot in the last 3 weeks, and am still learning.

Keep those pipes tied together!!!!!

Joe