presoaking coal

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lostintime
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presoaking coal

Post by lostintime » Mon Feb 12, 2018 11:18 pm

Long story short, im burning bit. Coal for the first time in a couple years (home heating) and was having allot of sooting problems, I took the advice of a 1800's blacksmithing book and presoaked the coal in water and (though today is the first test) it is burning clean at the moment. Does anybody have any experience or knowledge to impart?
(Edit) never had the soot problem before but then the coal was stored outside in the elements, now this stuff has been in a dry basement for about 5 years
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Mike Rometer
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Re: presoaking coal

Post by Mike Rometer » Tue Feb 13, 2018 1:24 am

I have found a problem with coal that has been stored 'open', not lighting, or burning well, even when stored for much less time than yours. It seems to lose the lighter fractions from the volatile portion. Try getting some fresh coal and mixing it.

If your coal is in a large pile you could also try getting some from the very middle of the bottom of the pile, but after that length of time I wouldn't be too hopeful.
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Lopez Mike
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Re: presoaking coal

Post by Lopez Mike » Tue Feb 13, 2018 1:40 am

But lostintime seems to be saying that he is soaking the coal in water. Which would be essentially weathering it just like letting it sit outside in the rain. I wonder of this treatment might be wasting off dirt and coal dust?

Our local coal here in the N.W. USA is horrible stuff. You end up with more clinkers that the volume of coal you burned. I think that it is just mud that has been painted black.
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cyberbadger
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Re: presoaking coal

Post by cyberbadger » Tue Feb 13, 2018 2:13 am

I have Kentucky Deepmine bituminous here in Ohio, it has lots of volatiles, like almost greasy.

Don't use it regularly on Nyitra but it always seems easy to burn if you just make a wood fire and then slowly start adding coal instead of wood.

-CB

P.S. So far I would say the little I've used my coal on Nyitra it has caused me soot issues...
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fredrosse
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Re: presoaking coal

Post by fredrosse » Tue Feb 13, 2018 2:19 am

The US govt studied the weathering of various coals, and only about 1 to 2 % reduction in heating value was observed. Bit. coal tends to smoke, and the general recommended solution is to keep sufficient "over-fire" air flow, and to spread fresh coal over only 1/2 the grate, so the volatile gasses are ignited and burned as they are driven out of the fresh coal by heat. Placing more coal only after the burning coal assumed incandescence throughout, then placing more on the other half of the grate.

Soaking in water would certainly increase the stack losses with all that water being boiled away, and passing up the stack, at about 1000 BTU loss for every pound of extra water in the wet coal..
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Re: presoaking coal

Post by Mike Rometer » Tue Feb 13, 2018 9:02 am

Fred, that 'boils' down :o to the old 'little and often' rule put about in railway steam days. It does seem to work regardless of the fuel.
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lostintime
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Re: presoaking coal

Post by lostintime » Tue Feb 13, 2018 11:59 pm

Only stokng half the grate at a time is making a big difference, and coal dust is a major factor. Before I was spreading it over the hottest parts and it would flair soot before I could even shut the fire door.
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Re: presoaking coal

Post by cyberbadger » Wed Feb 14, 2018 5:34 am

fredrosse wrote:Bit. coal tends to smoke, and the general recommended solution is to keep sufficient "over-fire" air flow, and to spread fresh coal over only 1/2 the grate, so the volatile gasses are ignited and burned as they are driven out of the fresh coal by heat. Placing more coal only after the burning coal assumed incandescence throughout, then placing more on the other half of the grate.

Soaking in water would certainly increase the stack losses with all that water being boiled away, and passing up the stack, at about 1000 BTU loss for every pound of extra water in the wet coal..
Wow! Thanks so much for this explanation.

Your explanation made me realize that I had been following a bit of advice from traction engine folks that doesn't necessarily translate correctly to vertical firetube boiler 100% in regards to the secondary flame from the volatile gases.

I had been following "Keep your grates covered" pretty religously.

After reading your explanation .. I think it depends on the air flow through the firebox and the state of the fuel in the firebox too....

This is what happens when the grate is covered but the secondary fire is not happening correctly...

This is an old video of mine with my first boiler. As I read your explanation Fred, this video immediately came to mind. ...

Disclaimer: I'm not saying anything you see in this video is right, it's just a video of some tinkering...



-CB
lostintime
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Re: presoaking coal

Post by lostintime » Wed Feb 14, 2018 6:04 am

That's about exactly what I was experiencing. The more I think about it I had replaced some windows and a door since I last burned coal and it is really reducing my draft. Right now I have a 16" deep bed of white hot coal on a 18" grate, having built up a scoop at a time alternating sides as it flared off. I appreciate the advice.
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