The Epoch of the Axeman

Isn't it amazing how close you can get to predicting consumption to only a few scant pounds with the use of HDD's.

lsayre wrote: ↑

Mon. Mar. 16, 2020 4:34 pm

Isn't it amazing how close you can get to predicting consumption to only a few scant pounds with the use of HDD's.

Yes that is amazing, I'm very impressed

Lightning wrote: ↑

Mon. Mar. 16, 2020 3:17 pm

I've noticed a lot of "black sand" in the ash bucket. To the point that material is piling up higher on the separation cone side of the ash tub.

That means your cyclone separator is doing it's job.

The Axeman auger will deliver the fines to the feed tube. Then they get dumped into the fire. Some of the fines that don't burn up will be inhaled by the fan and pushed into the cyclone separator, where the are promptly dropped into the ashpan, or on the floor.

Glad to see your HDD's are lining up with your coal usage. I think that means you are dialed in. I guess I should start doing that.

-Don

Thanks for the replies fellas I mighta blundered something this time around though. I'm getting 2.325 pounds per degree for the last 6 days which is about .3 pounds more than usual. I'm not sure what happened there. I see two days in row where I added 2 buckets which seems like an error. I'll try to pay more attention lol

Still a significant amount of black sand in the ashes which accounts for the 17%



03/14 2:00pm bin level/empty tubs
Date....#'s added.......average OAT(F)
03/15 +90.................32.2
03/16 +43.................33.6
03/17 +80.................37.3
03/18 +92.................36.7
03/19 +44.................46.9
03/20 +58.................59.5

Coal Total #'s 407 Ash #'s 69
Coal vs Ash 17%
Days 6 ... #'s per day 67.8
Minus 12#'s for loop and DHW
55.8 #'s/day for heating 2900 sq ft
Average Temp 41 degrees
2.325 pounds/HDD (base 65)

Efficiency wanes with warmer weather. Are you accounting for the boilers baseline needs just to maintain a fire on days when no home heating is needed?

Using my boiler as an example:

~11 lbs per day just to keep the fire lit
~3 lbs. per day for dHW
~14 Lbs per day overall when its warm outside

3/14 = 21.43% efficiency in making DHW only.

lsayre wrote: ↑

Fri. Mar. 20, 2020 4:31 pm

Efficiency wanes with warmer weather. Are you accounting for the boilers baseline needs just to maintain a fire on days when no home heating is needed?

No I didn't think of that. Also, my boiler and near boiler piping has zero insulation so standby loss would skew it also..

Here is the "spreadsheet format" equation I would initially presume for your system.

Anticipated Coal Burned Per Day = IF(65-Days_Avg_Temp>5.384,(65-Days_Avg_Temp)*2.043+12,23)

Where:
23 = 11 lbs. to keep the fire lit + 12 lbs for the underground loop and DHW, or the minimum you can burn in a day.
12 = coal accounted for by the underground loop + DHW
2.043 = Lbs. burned per HDD for home heating
5.384 = (23-12)/2.043 (meaning that at or below 5.384 HDD's for any given day you will burn 23 Lbs. of coal for that day)

What the equation states "verbally" from left to right in simplified word form (beginning at the 'IF' statement) is:

If you experience greater than 5.384 HDD's for any given day, then on that day you will burn (65 minus the Days_Avg_Temp) x 2.043 pounds of coal, else you will burn 23 lbs. of coal.

To validly compute Lbs. burned to heat your home and Salon on any given day you must experience greater than 5.384 HDD's for that day. Otherwise that day must be excluded from your monthly "home heating only" computational data set, and for that excluded day you must simply presume to have burned 23 pounds of coal.

Yeah... I'll need a little time to process all that lol. But I thank you, I'm sure it makes good sense

I just changed "greater" to "less". Hopefully that correction makes for better sense.

EDIT: OK, back to "greater". I had it right to begin with....

I've got a question for you AA experts. Today I got a few pics from underneath. There is quite a bit of glow under there. I'm wondering if y'all think I should tweak the anthrastat a little bit. It's set around 142 degrees. The ratchet is set at 1-2 clicks which I like because it adds small increments of coal to the fire over time instead of a lot at once.. I've ran these settings for most of the heating season but this is the first time (or maybe I did early in the season, not sure lol) I've crawled inside to see what is happening on top the ash sled.

So if I were to lower the anthrastat temp, that should cause the ash layer to thicken.. is that correct?

I should also point out that in the picture it appears that the fuel bed rim is glowing but in person it is dark. I think the camera is picking up some reflection of live coals on the ash sled since there does appear to be some.

I should also add that I have noticed the anthrastat halting the ash sled on long heat calls like it's meant to, so I do believe it's working properly, but wonder if I should tweak it to thicken the ash layer..

One thing that has been different over the last few weeks is that I've been scooping under the coal chute door. There has been a lot of small peices and fines. I do speculate that these small peices and fines have inhibited combustion air flow thru the fuel bed. It's my thinking that if there is slower combustion as a result, this would cause the fire to make it's way down to the grate. So having said that, maybe this would clear up with cleaner coal..

I have noticed a little more coal in the ash lately. It has also thrown my coal vs ash percentage kinda high. At first I blamed it entirely on the "black sand" in the ashes but now after seeing the fire get down to the ash sled I'm thinking the "black sand" is only part of the extra weight.

What's your thoughts on that?

Seeing hot coals down there is not what you want. It eventually will eat the lower ring of the firetube. I suggest you get the fire up higher, stop ashing now and raise the anthrastat setting. Normally this is about 140°. You also risk puffbacks. Can you post a pic from the observation port?

Edit: Just saw your pic of the anthrastat setting, are you sure it's calibrated properly? I've run some real crap through mine and never really fiddled with the anthrastat setting. Once set, it should rarely need adjustment if ever.

coaledsweat wrote: ↑

Mon. Mar. 23, 2020 9:40 pm

raise the anthrastat setting

This is where I get confused.. from what I understand the anthrastat opens on temperature rise. When it opens, power is cut to the solenoid which stops it from ashing. So if I raise the temperature it will need more heat to stop ashing. Don't we need it to stop ashing earlier? Seems like I should need to turn the anthrastat setting down..

Or is my thinking backwards?

I've also thought about replacing the anthrastat with a digital controlled relay this summer. Seems like a good place to check temperature would be right on that lower combustion tube ring. When it starts getting hot (above the water temperature) the ashing should stop, since that would indicate the fire is descending below the boiler vessel.

No, you're right. Lower the temperature. I've been locked up to long and not thinking straight. Stop ashing, and reset the anthrastat. I like to see the fire just break the surface and start there.