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Small "boom" inside

Posted: Fri. Dec. 06, 2019 8:12 pm
by Thyrantt
I'm not a native english speaker to excuse my grammar and mistakes. Anyways, a few minutes ago I went to fill up the coal boiler and when I filled it up, after closing there was like a small thud (boom) inside and smoke just rushed where the small doors are. Pressure is unchanged, water isn't leaking anywhere, everything seems fine.

Should I be worried? Should I check something more?

I can provide images for better explanation if needed.

Re: Small "boom" inside

Posted: Fri. Dec. 06, 2019 8:16 pm
by Lightning
That is called a "puff back".. it happens sometimes when conditions are right after loading fresh coal.

Re: Small "boom" inside

Posted: Fri. Dec. 06, 2019 8:17 pm
by grumpy
You had a puff back, it could have been much worse. Too much coal too fast, someone will set you strait soon.. guys ?

Re: Small "boom" inside

Posted: Fri. Dec. 06, 2019 8:17 pm
by Lightning
No problem unless the stove pipe comes apart..

There are ways to prevent it from happening.

Re: Small "boom" inside

Posted: Fri. Dec. 06, 2019 8:23 pm
by Thyrantt
Lightning wrote:
Fri. Dec. 06, 2019 8:16 pm
That is called a "puff back".. it happens sometimes when conditions are right after loading fresh coal.
Ah, thank you. Was scared there for a moment.

It was the first time that it happened in 5 years, so I didn't what it was haha.

Re: Small "boom" inside

Posted: Fri. Dec. 06, 2019 8:24 pm
by franco b
Soft coal is about one third gas. That gas is given off rapidly when a fresh load of coal is loaded. You must provide over fire air to allow it to burn safely, instead of accumulating to the point of finally getting enough air and then exploding.

You could also load in two smaller batches.

Re: Small "boom" inside

Posted: Fri. Dec. 06, 2019 8:27 pm
by Lightning
Ah, good call franco, I didn't notice he was using bit coal..

Re: Small "boom" inside

Posted: Fri. Dec. 06, 2019 8:29 pm
by Thyrantt
franco b wrote:
Fri. Dec. 06, 2019 8:24 pm
You could also load in two smaller batches.
That's how we always did it, not intentionally, as we're using that big paint bucket.

Re: Small "boom" inside

Posted: Fri. Dec. 06, 2019 8:36 pm
by franco b
Thyrantt wrote:
Fri. Dec. 06, 2019 8:29 pm
That's how we always did it, not intentionally, as we're using that big paint bucket.
Yes, but you must give the first bucket time to give off gas and burn before adding the second bucket.

Stoves designed for that coal have special air handling parts that direct heated air directly over the fire to ignite the gas.

Re: Small "boom" inside

Posted: Sun. Feb. 21, 2021 4:12 pm
by stovehospital
How to avoid puff backs. When you load the stove after dropping the the ashes etc. Fill the pot then use a slicing iron. Slicing irons are straight, fairly think and have a point with a spade shape on the end. Push the iron down through the new coal at the front of the box all the way to the grate bars. Move it in a circle and make a nice little chimney that will bring very hot gases from the grate up to the surface. I locate the hole so that when I close the door it is right next to the secondary air intake. That way any gas that is released in the area will ignite and burn off before it can accumulate. That will end the puff problem.