Coal ash from Harman Mag Stoker

 
Coalnoob
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Post by Coalnoob » Sun. Oct. 28, 2018 10:21 pm

This is my first year burning coal, I am using a used Harman Mag Stoker. I have burned it for about a week now and it is producing heat very well. I set the verti flow settings to factory simply for a safe place to start. I am wondering what my ashes in the ash pan should look like? Because I have never burned coal before I do not know if my unit is operating efficiently or not in regards to the complete burning of the rice coal. I do know the unit is not over firing or going out which is a good thing thus far. I simply want to make my unit as efficient as possible without losing money on wasted unburned coal. Thanks for the help.


 
titleist1
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Post by titleist1 » Mon. Oct. 29, 2018 7:08 am

Here is a pic of my ashes. This is about two days worth. What does yours look like and what are your idle fire timer settings? Mine are about 2 min on and 12 min off, i haven't used a stop watch on it yet this year but it is close to that.
20181029_064059.jpg
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Coalnoob
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Post by Coalnoob » Tue. Oct. 30, 2018 10:06 pm

I am at the factory recommended settings of on time 4, off time 12, and distribution blower 2. I have about half a pan of ashes per day. It does look similar to yours. It’s heating about half my house right now. It’s long, all one level, no basement unfortunately. I have it hooked to a Honeywell programmable thermostat. I got it used and replaced a few parts. So far so good and it is a well built stove for sure.

 
Mattw205
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Post by Mattw205 » Fri. Nov. 02, 2018 9:36 am

i cant comment on the stove settings at all as i dont have any experience with it but as far as the ash goes, looks very similar to what my stove produces.

 
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captcaper
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Post by captcaper » Sun. Nov. 04, 2018 1:21 am

Looks good to me. The black rocks are rocks..

 
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Post by titleist1 » Mon. Nov. 12, 2018 1:34 pm

So I had time at lunch today and actually remembered to sit (after kicking the cat out of the office chair by the stove) with my phone stop watch and time the idle timer settings for the stoker. My memory was off a bit from the times i posted earlier in this thread, i am at 3min 2.14 sec ON time for the feed motor / combustion blower, 15min 4.66sec OFF time and the distribution blower runs for 13min 1.43sec after the feed motor and combustion fan go off. (+/- .05 seconds!! :lol: )

It keeps the fire between 'stat calls, burns the coal thoroughly enough to satisfy me and it keeps the draft going the correct way on warmish days, although i do put foil over the baro when we hit 60*. I don't feel the need to tweak the timing in any way at this point. :yes:

 
Coalnoob
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Post by Coalnoob » Thu. Nov. 15, 2018 4:57 pm

Where do you have your push rod set? Two dots? Three dots? I have mine at two dots. I’ll probably change my settings to mirror yours and see how that works.


 
titleist1
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Post by titleist1 » Thu. Nov. 15, 2018 10:52 pm

I am feeding 2.5 dots but you may need a different feed rate. I helped a friend set his up this past weekend and his settled on a 2 dot feed rate. The feed rate was adjusted after the combustion fan cover was set. You want to watch the manometer when it is measuring your over fire draft and make sure you aren't pressurizing the firebox by having the cover open too far on the combustion fan. Once the cover is set, then you want to watch the ash at the end of the grate and try to get a 1" - 2" band by adjusting the feed rate.

 
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Post by Coalnoob » Sun. Nov. 18, 2018 9:00 am

My fire is a little further back on the grates, but the fire is about 2” when it’s going. Ash now looks like yours and I generally just dump it once a day when it’s 20 degrees or so.

 
garyonthenet
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Post by garyonthenet » Sat. Nov. 24, 2018 5:09 pm

I too have a Harman Magnum Stoker; the mfr of the stove come from the 80's, which I bought used, and renovated, but it is still solid.
However I found that the integrated automatic(ish) blower and coal feed servo mechanisms that it came with were unworkable, constantly trying to get that sweet spot between where coal was fed too fast, and enough to keep it from going out:
harman stoker Verti-Flow Ctlr Box.jpg
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I had to design and build a completely separate internal/external temperature & coal feed controller, which has made it thoroughly practical and something I don't have to babysit every hour.
The genius of the controller I built, was separating the coal feed from the internal blower activation.
The controller blows the internal blower to keep the inside quiescent temperature, and only feed coal when what is on the pan is used up. I never have to adjust the feed rate push rod now, I always have it on the highest setting, and the controller makes sure it never overfeeds. The efficiency is much higher now, it never goes out and never dumps unburnt coal into the ashpan. The wall thermostat now also is much more effective, kicking in when the room temp is too low; usually the internal quiescent temp is enough to keep the room slightly warmer that the wall thermostat.
Now it is copacetic, I like the heat it gives out, it is actually adjustable between 4000btus and 110,000 btus and does so automatically, and the low cost of the fuel, about 1/3 the cost of heating oil.
If you are interested in the controller device I built let me know, and I can give you more details and photos.

 
garyonthenet
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Post by garyonthenet » Sat. Nov. 24, 2018 5:33 pm

captcaper wrote:
Sun. Nov. 04, 2018 1:21 am
Looks good to me. The black rocks are rocks..
The question I would have is, how much can be regular rocks vs what you are paying for, anthracite coal.
I have sometimes needed to sift the ashes to get back unburnt coal, and you'd be surprised as to how much unburnable rock is in there.

 
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Post by CapeCoaler » Sat. Nov. 24, 2018 10:32 pm

If you are interested in the controller device I built let me know, and I can give you more details and photos.
Well of course!...
So your controller totally replaces the Harman Stoker control?...

 
titleist1
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Post by titleist1 » Sun. Nov. 25, 2018 8:02 am

garyonthenet wrote:
Sat. Nov. 24, 2018 5:33 pm
The question I would have is, how much can be regular rocks vs what you are paying for, anthracite coal.
I have sometimes needed to sift the ashes to get back unburnt coal, and you'd be surprised as to how much unburnable rock is in there.
I changed suppliers years ago because i was getting too much rock in with the coal. I think it was because their stockpile was not on blacktop or concrete and when they ran the bucket into the pile they were scraping the ground. After asking them to run the bucket into the pile a foot or so off the ground and watching him scrape the ground again I declined the load an left for another dealer.

The dealer i currently use has blacktop stock yard and i never get anything but clean coal from them.

And of course we are interested in pictures and more details on your controller!! :clap:

I have an extra Harman controller here that is bad ans I keep meaning to dissect it and see if I can figure out the bad component but we need a longer winter and fewer inside winter projects for that to bubble to the top of the list.

 
garyonthenet
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Hot Air Coal Stoker Stove: Harman Magnum Stoker
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Post by garyonthenet » Mon. Nov. 26, 2018 12:51 am

CapeCoaler wrote:
Sat. Nov. 24, 2018 10:32 pm
Well of course!...
So your controller totally replaces the Harman Stoker control?...
It does, the only things I didn't build into it is the distribution blower extended on time or the periodically timed-on internal blower. I could put those into it later as well, but since those last functionalities were still in the Verti-Flow controller, I didn't see the need to repeat those. Of course it would be more complete if it did everything on its own. It wouldn't take much more effort, just a timer circuit.
The controller I built has an output that goes into the vertiflow's controller where you would normally put the wall thermostat into.
My controller takes as inputs: [1] the wall thermostat, [2] an internal thermometer that is inside the stove, [3] A/C power.
It has outputs: [1] an A/C outlet that goes to the coal feeder, [2] a signal wire to the vertiflow's thermostat input port.
I just saw your replies here so I didn't get chance to take pictures, but my next post I will bring some pictures to show you all.

 
titleist1
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Post by titleist1 » Tue. Nov. 27, 2018 7:46 am

Very interesting idea, using the internal temp probe for feeder control. :yes:

Do you still have the distribution blower plugged into the Harman controller to make use of the shut down delay timer?

Where do you power the combustion fan.... from the Harman controller, your controller, or is it running all the time?

It sounds like you had to adjust the feed rate frequently and experienced a lot of outfires when using the Harman controller. You mention babysitting it hourly and I am curious what your timer setting were at that made that necessary?


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