Unburned (underburned) Coal in Harman Magnum

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Greg Sarris
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Location: New Park, PA
Stoker Coal Boiler: Harman Magnum
Coal Size/Type: Rice

Post by Greg Sarris » Tue. Feb. 12, 2019 2:07 pm

Hello,
This is my first post as I am new (within a few weeks) to this site and to burning coal in general.
Question for you all regarding under-burned coal.
I have installed a good condition Harman Magnum in the basement of my farm house.
Below is my operating situation/information.

Chimney is 6" square with round ss liner--approx 28-30'.
Barometric damper has been set to .04. Combustion flap is adjusted to give a front of stove reading of .03-.04.
I have replaced every gasket that I know of including the gasket under the fire pan.
The pivoting clean out piece is tight up against the bottom of the fire box.
Combustion fan has been cleaned out and flows as it should. Combustion fan is also correctly pushed into place.
Area in between combustion fan and fire box is clean and clear.
I re-drilled-cleaned out the grate holes with a 1/8" drill bit. Grates are fitting correctly from what I can tell.
Stoker is adjusted so that 1-2" of ash is present before falling off of grate--no hot clinkers falling.

Problem is, regardless of how much combustion air volume or stoker adjustment, I have quite a bit (estimate 20 lbs per 120lbs of coal) of unfinished coal which is mixed in with the ash.
I realize that some of what I am seeing is not coal but other materials--however, when I agitate, sift, and re-burn the material I collect, it burns almost as well as the coal on the first run.

Here are a few observations which maybe some of you can use to advise me if possible.

- It seems that when viewing the spent ash cake before it falls into the ash pan-it is the top layer (upper portion) which contains most of the unfinished coal. Seems that the coal closer to the grates turns into the "granola" looking product and the material on top is unfinished.

--It also appears that once the bottom layers (closest to the grates) are expired --perhaps it causes the upper layers to stop burning perhaps? Or perhaps, the ash on the bottom cuts off the air to the top of the cake?

--I have experimented with halting the pusher block and letting the combustion eat away at the coal to see if I could get the coal to turn to ash that way--made very little difference.

--Tried both Blaschak and Lehigh coal--both act very similar. Coal is fairly dry (it is bagged however)

I can continue sifting and rerunning the coal--it is not really a big deal--but of course, I would rather fully (or closer to fully) burn the coal on the first go around. Plus--I am running out of dust masks!!
Sorry for the long first post- just wanted to get all the info out here as possible.
I have read as many posts on this site as possible over the past few weeks before posting--which allowed me to learn a bunch and make some good adjustments, but I feel that I have overlooked something.

Any ideas would be appreciated.

Thanks, Greg

 
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McGiever
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Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
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Hand Fed Coal Stove: Warm Morning 414A
Coal Size/Type: PEA,NUT,STOVE /ANTHRACITE
Other Heating: Ground Source Heat Pump and some Solar

Post by McGiever » Tue. Feb. 12, 2019 3:11 pm

Welcome to the forum! :)

Removing that round stainless steel flex liner will give you a better fire...right now that is your limiting factor.

 
titleist1
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Post by titleist1 » Tue. Feb. 12, 2019 4:29 pm

Welcome to the forum!! :clap:

You have certainly done a good bit of homework trying to optimize the burn. Those are all things that need to be checked out.

A few questions...What % of run time is from the thermostat versus the timers? If you are running off the timers a lot this is the characteristic of the stoker. If you are running pretty much full time via a call for heat from the 'stat, then maybe it should do a little better for you.

I have had issues once with getting a good burn from the coal when it has been too wet and 'sticky' with fines. Damp is OK, wet is no good.

How far open is the restrictor plate on the comb fan? What are the temps on the sides of the stove and the top middle above the door?

When running a lot on timers, some have plugged the combustion fan directly into an outlet instead of the control box to get a more complete burn.

Could you post a pic of the ash?

 
Greg Sarris
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Stoker Coal Boiler: Harman Magnum
Coal Size/Type: Rice

Post by Greg Sarris » Tue. Feb. 12, 2019 5:59 pm

Thanks for the replies!
-In terms of percentage "on" and "off". Currently I have been running the stove "on" constantly for a few days. I have shut the oil burner down and have used this stove exclusively to heat the house. Only for a very brief amount of time has it satisfied the thermostat and went into idle mode in the past week.
-Both brands of coal are bagged. The Blaschak is drier out of the bag than Lehigh. The Lehigh bag leaves a damp spot on the concrete floor if it sits there for a while. It may be on the "wet" side. I have thought of getting a large pan to spread out the coal to let it air dry--but I am afraid the cats will take a liking to it if you know what I mean. I only fill the hopper with half a bag at a time if I can (when I am home from work) to help dry off some of the moisture and to avoid large amounts of damp coal in the hopper. I also leave off the hopper lid.
-Currently, the combustion damper is about 1/4-1/3rd open, but, I get the same result if it is wide open. Of course, the flame shape and size changes with the change in the combustion flap opening, but the issue I am having remains regardless. As well, the flame burning edge responds accordingly to the combustion flap opening as it should.
-As far as temps--I have misplaced my digital infrared thermometer-but the top of the stove is reading according to the magnetic thermometer between 375-450 degrees F. I did let it run more unbridled last weekend and brought the stove-top temp up to around 550 temporarily- but then I got the feeling that I should back it down a bit. I have not measured the side temps yet, but I will have that info as soon as I dig up my thermometer or move the magnetic one to the sides.
-I will take a picture of the ash as soon as I get a load of ash and my wife is home with her fancy phone to take the picture. I just sifted the ash I collected today to do a rerun maybe this evening.
I am surprised as to how similar the rerun burns to the original. I usually have to only increase the pusher by 3/4 of a turn to match the first run of coal in terms of the fire line and heat output.
Thanks again for the reply.
Greg

 
titleist1
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Post by titleist1 » Tue. Feb. 12, 2019 7:43 pm

The 1/4 to 1/3 open is closed off more than usual in my opinion which means causing less airflow through the coal bed. However, you need to set that according to the draft your install can support so you don't pressurize the firebox... which means you can't just open it wider without knowing the additional air can be exhausted through your SS flex liner. McG's post covered that limitation. Was there a compelling reason for the liner?

The lower airflow also means lower stove temps. For comparison, my plate is just over 1/2 open & when running flat out during the recent cold snap the side temps were 600 and above the door on the front was about 630 measured with the IR temp gun.

Cats will use a nice rice coal pile if given the chance. Use the IR temp gun to drive them nuts when you find it! :yes:


 
Greg Sarris
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Stoker Coal Boiler: Harman Magnum
Coal Size/Type: Rice

Post by Greg Sarris » Tue. Feb. 12, 2019 8:05 pm

Thanks again for your reply.
I put the ss liner in back when I installed the wood stove. I installed the ss liner because I was unsure of the chimney itself and wanted an extra measure of safety in that regard. The chimney is ok, regular masonry with typical masonry liner.
In terms of draft, I had to set the counter weight forward completely to get it down to .04. With the barometric damper closed--it was over .08.
Are you suggesting another parameter besides draft with respect to the liner and chimney sizing? For example, can I have more than adequate draft readings but not enough airflow (cfm) due to the size of the flue?
I do remember when I installed the liner when I had the wood stove, the draft increased dramatically compared to when it was just the chimney without the liner. I have not really operated the stove hard to see how hot I can get it because I don't really know what is the temp limit. I have of course read what Harman says regarding the size of the fire, but that is less precise that temp figures. Do you have an idea of what the upper limits should be in terms of temps for this unit? I usually tried my best to keep the wood stove below 650 or so when I had it going, but that was of course a different unit.
Would readjusting the barometric damper to give the stove more than .04 draft assist due to having volume limitations from the ss liner?
Greg

 
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McGiever
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Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
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Hand Fed Coal Stove: Warm Morning 414A
Coal Size/Type: PEA,NUT,STOVE /ANTHRACITE
Other Heating: Ground Source Heat Pump and some Solar

Post by McGiever » Tue. Feb. 12, 2019 9:34 pm

This coal will not mimic any wood you have burned...it is different.
It can be a surprise when the fire box goes positive with excess fan air adjustment or inadvertent reduced draft volumes...

Be sure to have a working Carbon Monoxide detector in place.
And try keeping that hopper lid on all the time.

 
Greg Sarris
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Post by Greg Sarris » Tue. Feb. 12, 2019 10:10 pm

I found my IR thermometer. (left it in my f250 from the last time I was trying to determine which plug wasn't firing)
Here are the results.
Front of stove just above front door--- 475 degrees.
Sides of stove at about the same height as firebox or above--- 450 degrees.
Stovepipe immediately after exiting stove--- 220 degrees.
Stovepipe immediately before barometric damper---170 degrees.
Stovepipe after barometric damper to the wall---135 degrees.
I am not sure of my stovepipe readings--they seem a little too low to me. I can however, keep my hand on the stovepipe after the barometric damper for about 4 seconds. Perhaps the stovepipe is somewhat reflective and messing with my thermometer. It wouldn't surprise me if the stovepipe readings are at least 30-40 degrees higher--just from feel--but according to the thermometer with fresh batteries, that is what it says.
I am running the stove currently with a good 1.75-2" of ash out front of the flames.

I have one CO monitor/alarm in the basement with the stove and one CO monitor/alarm upstairs on the first floor where we sleep. So far, so good with them.

Ill put the lid on the hopper back on directly.

Thanks for all the help so far fellas.
Greg

 
gumptruck
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Post by gumptruck » Thu. Jan. 16, 2020 2:35 pm

Have u solved the unhurt coal mystery. and what did u make to screen coal

 
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StanT
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Post by StanT » Fri. Feb. 14, 2020 12:46 pm

Is your coal the same as this chart or bigger? I had same poop. some are mixing buckwheat with rice as all the rice goes out of state. Unless screens are worn out.
DiRenzo Coal Co., LLC
Quality Anthracite Since 1930

Our Strategic Location at the Center of
America's Largest and Most Productive
Anthracite Coal Field allows us to economically
blend from different coal seams for
Optimal Quality & Performance.

We produce all of the following standard
sizes of Pennsylvania Anthracite Coal...

Egg - about the size of a softball
Stove - about the size of a baseball
Chestnut - about the size of a golfball
Pea - about the size of a quarter
Buckwheat - about the size of a dime
Rice - about the size of a corn kernel
Barley - about the size of a rice grain

Custom Size Blending is available.
Please inquire.

About Anthracite Coal...
Good luck, Stant


 
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Post by gumptruck » Fri. Feb. 14, 2020 12:53 pm

What is price of your rice coal right now. what month do u drop coal prices for summer. whats it generally go for in summer

 
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StanT
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Post by StanT » Fri. Feb. 14, 2020 7:02 pm

DiRenzo Coal Co.
Quality Anthracite

Current Price Schedule
Effective Fri, November 29, 2019

PER TON
Stove ------------ $180
Chestnut -------- $180
Pea -------------- $170
Buckwheat ----- $170
Rice ---------------$180
Barley ------------ $130 Here you go, Stant

 
BostonBob
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Hot Air Coal Stoker Stove: Harman DVC500,Alaska Gnome 40
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Post by BostonBob » Fri. Feb. 14, 2020 10:34 pm

Hi Greg Welcome to the Forum ! I have a Harman DVC 500 with a control board also, I have mine in the stove temperature mode set at 1 1/4 to 1 1/2 with the feed at 1 1/2 to 2 the temperature just above the door is 275 - 300 the house is a comfy 74. My grates have to be fire caulked down so the fire🔥 is even on the grates, in your install book do you have to do that also ?

 
BostonBob
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Post by BostonBob » Fri. Feb. 14, 2020 10:44 pm

I burn Blaschak coal, and I empty my bags into a bin 5-7 bags at a time to dry, and then fill 5 gal buckets and place them in front of the stove (2 buckets 1 I fill the hopper with, the other is drying more) damp coal is ok but the dryer the better :D

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