Better Coal Run at 3?

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daluds
Member
Posts: 282
Joined: Fri. Jun. 20, 2008 9:27 am
Stoker Coal Boiler: EFM DF520
Coal Size/Type: Rice
Stove/Furnace Make: EMF
Stove/Furnace Model: DF-520

Post Tue. Jan. 19, 2010 8:03 am

I changed settings this year trying to keep the fire from going out, and ended up increasing the settings from 3/3.25 to 4/4. In the end, what fixed it is lowering the timer by a minute since this years coal is much easier to burn or burns hotter, and was always hitting the hi limit of 200. I did not go back to 3/3.25, but using a lot more coal this year. The temp pegs at the high limit of 200 most of the time. Should I lower it back to 3/3.25? I did try it one weekend, and noticed it was struggling to keep it at 160 with demand for heat in multiple zones so left it at 4/4.

So is it better to run a lower setting over longer period of time or higher setting for shorter period of time (pegs at high temp) to conserve on coal usage? I am going through about .5 more tons per month with this new coal and settings. Its difficult to judge the heat usage compared to last year, but assume its similar. I used 3 tons this year so far, and last year used 7 tons in the winter.

Thanks,

Dave

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stoker-man
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Posts: 2063
Joined: Mon. Nov. 19, 2007 9:33 pm
Hand Fed Coal Boiler: 1981 efm wcb-24 in use 365 days a year
Coal Size/Type: Anthracite/Chestnut
Other Heating: Hearthstone wood stove
Location: Lehigh Valley, PA

Post Tue. Jan. 19, 2010 11:25 am

If your ash ring is good, your coal use is because of your heat demand.

At efm, I have the low at 150 and high at 200 and reduced the timer to 1 1/2 minutes per half hour. On a day in the 40's, the boiler idles at 220 almost all day, but have never had an outfire with 9 feed and 9 air and about 9 tons of coal thus far. The temperature gauge shows 150 throughout the entire 8 to 12 hours straight that it runs each morning.

I did have a single outfire early in the season, but it was caused by the second high limit aquastat.

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coal berner
Member
Posts: 3590
Joined: Tue. Jan. 09, 2007 12:44 am
Stoker Coal Boiler: 1986 Electric Furnace Man 520 DF
Stove/Furnace Make: Electric Furnace Man
Stove/Furnace Model: DF520
Location: Pottsville PA. Schuylkill County PA. The Hart Of Anthracite Coal Country.

Post Tue. Jan. 19, 2010 12:15 pm

daluds wrote:I changed settings this year trying to keep the fire from going out, and ended up increasing the settings from 3/3.25 to 4/4. In the end, what fixed it is lowering the timer by a minute since this years coal is much easier to burn or burns hotter, and was always hitting the hi limit of 200. I did not go back to 3/3.25, but using a lot more coal this year. The temp pegs at the high limit of 200 most of the time. Should I lower it back to 3/3.25? I did try it one weekend, and noticed it was struggling to keep it at 160 with demand for heat in multiple zones so left it at 4/4.

So is it better to run a lower setting over longer period of time or higher setting for shorter period of time (pegs at high temp) to conserve on coal usage? I am going through about .5 more tons per month with this new coal and settings. Its difficult to judge the heat usage compared to last year, but assume its similar. I used 3 tons this year so far, and last year used 7 tons in the winter.

Thanks,

Dave
Each tooth on feed drum = 2.5 lbs per hr on rice coal 2 lbs per hr on buckwheat coal.
Depending on what coal you are using and what the heat demand for your house is how much chimney draft control you have You might need to use a higher feed rate or you my not need to .

3 teeth is 7.5 lbs per hr 4 teeth is 10 lbs per hr with Rice coal So at 3 teeth if the coal is burning at 13.000 BTU's per lb
that would be 97.500 BTU's per hr subtract 15% 85 % efficiency to 20 % 80% efficiency for heat loss 97.500 - 15% is 14.625 BTU's loss so it is 82.875 BTU's per hr At 20% loss - 19.500 BTU's loss So your down to 78.000 BTU's per hr .

4 teeth 10lbs per hr coal at 13.000 per lb 130.000 BTU's per hr - 15% 19.500 heat loss down to 110.500 BTU per hr .
20% heat loss 26.000 BTU loss so you are at 104.000 bt's per hr

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