Coal BTU content vary with years?
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- New Member
- Posts: 6
- Joined: Sat. Nov. 12, 2022 11:10 am
- Stoker Coal Boiler: Keystoker KAA2
- Coal Size/Type: rice
- Other Heating: Utica oil boiler
Good morning, havent used my boiler in 3 years and this year I cannot get it to run over 120 deg. Gave it a thorogh cleaning yesterday ant it is set up to Keystoker specs (KAA22). Does coal BTU output change year to year? I have always used Blaschak ( since 2008) and this is the first year it doesnt run very well. Any ideas?
- SMITTY
- Member
- Posts: 12525
- Joined: Sun. Dec. 11, 2005 12:43 pm
- Location: West-Central Mass
- Stoker Coal Boiler: EFM 520 Highboy
- Coal Size/Type: Rice / Blaschak anthracite
- Other Heating: Oil fired Burnham boiler
Make sure there's nothing blocking the airflow. You'd have to let the fire go out, and maybe remove the stoker assembly depending on how much room you have in there.
My old flat bed stoker used to get little pieces jammed in the holes, and every fall I'd have to poke them through with a tiny screwdriver or piece of wire, plus vacuum out a MOUNTAIN of fines beneath the bed. The fines really choked off the BTU output, since it restricted and redirected airflow.
My old flat bed stoker used to get little pieces jammed in the holes, and every fall I'd have to poke them through with a tiny screwdriver or piece of wire, plus vacuum out a MOUNTAIN of fines beneath the bed. The fines really choked off the BTU output, since it restricted and redirected airflow.
- nepacoal
- Member
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- Joined: Wed. Nov. 21, 2012 7:49 am
- Location: Coal Country
- Stoker Coal Boiler: Keystoker KAA-4 / "Kelly" and an EFM 520 at my in-laws
- Hand Fed Coal Boiler: Harman SF-260 - retired
- Coal Size/Type: Buck
Maybe a blocked chimney or an open chimney clean out door. Are you smelling any sulfur at all? Is your triple aquastat acting normal? Your stoker should never turn off if the temp remains below your low limit. A video of your fire would definitely help.
Last edited by nepacoal on Fri. Feb. 10, 2023 2:57 pm, edited 1 time in total.
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- Member
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- Joined: Sun. Mar. 25, 2007 8:41 pm
- Location: Ithaca, New York
- Stoker Coal Boiler: Keystoker KAA-4-1 dual fuel boiler
- Hand Fed Coal Boiler: former switzer CWW100-sold
- Coal Size/Type: rice
- Other Heating: kerosene for dual fuel Keystoker/unused
You have a kaa2 not a kaa22 right??
All types of coal fuels can vary in carbon content and the BTU per pound.
If the entire fire bed of your kaa-2 has a fire on it, it may feeding too much coal
as you need to have a 2+ inch band of ash band of ash at the base of the
fire grate a 2 inch band of fire and the rest of the coal being unburned coal.
I reduced my coal flow rate by two thirds by reducing the size of the hopper
draw point and I am burning much less coal and still having plenty of heat.
If you have not changed the air setting for the squirrel cage blower you should
back the stoker feed off by 2 threads and wait to see what the fire looks like in
a couple of hours.
It is entirely possible that your unit may have a mountain of fly ash in the flue
breech blocking the flow of flue gasses and it needs to be cleaned.
This occurred with my kaa-4-1 as I was never aware the flue baffle could be
removed to clean behind it until I bumped it and it slid sideways.
When I did remove the baffle the very first time I found had a mountain of fly ash
in the flue breech and I vacuumed it all out.
I would check behind the baffle first for fly ash build up and then slow the feed rate
down by 2 threads.
All types of coal fuels can vary in carbon content and the BTU per pound.
If the entire fire bed of your kaa-2 has a fire on it, it may feeding too much coal
as you need to have a 2+ inch band of ash band of ash at the base of the
fire grate a 2 inch band of fire and the rest of the coal being unburned coal.
I reduced my coal flow rate by two thirds by reducing the size of the hopper
draw point and I am burning much less coal and still having plenty of heat.
If you have not changed the air setting for the squirrel cage blower you should
back the stoker feed off by 2 threads and wait to see what the fire looks like in
a couple of hours.
It is entirely possible that your unit may have a mountain of fly ash in the flue
breech blocking the flow of flue gasses and it needs to be cleaned.
This occurred with my kaa-4-1 as I was never aware the flue baffle could be
removed to clean behind it until I bumped it and it slid sideways.
When I did remove the baffle the very first time I found had a mountain of fly ash
in the flue breech and I vacuumed it all out.
I would check behind the baffle first for fly ash build up and then slow the feed rate
down by 2 threads.