Flue has temps.

 
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Jjones6840
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Post by Jjones6840 » Sun. Oct. 14, 2018 1:07 pm

I just started using coal last year for the first time in my furnace. I’ve used firewood most of my life. When burning wood cranking my stove pipe would be around 750 external temps and down low 300-350 degrees external temps. Now I am burning coal, reading internal temps this year is about 110 down low and 140 with draft door spin down open. Does that seem right to you guys? It seems low to me


 
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Lightning
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Post by Lightning » Sun. Oct. 14, 2018 1:16 pm

So just to be clear we're comparing external temps with wood and internal temps with coal. Is that right?

I measure external temps of the stove pipe and external temp of the furnace face a few inches above the load door. Currently at a low slow burn the external stove pipe temp is 165 and above the load door is 198. Coal will have much lower stove pipe temps than wood.

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Jjones6840
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Post by Jjones6840 » Sun. Oct. 14, 2018 1:29 pm

Yes, last year I used a magnet thermometer on the stove pipe, this year I have two temp controllers with thermocouples to measure the inside temp of stove pipe
Last edited by Jjones6840 on Sun. Oct. 14, 2018 1:47 pm, edited 1 time in total.

 
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Post by Jjones6840 » Sun. Oct. 14, 2018 1:31 pm

BDFDC5DB-8580-445B-ABFD-27B68374A028.jpeg

This is low and slow


 
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Post by Lightning » Sun. Oct. 14, 2018 2:52 pm

Okay so, two controllers measure the inside pipe only? Or is one external? And what do all the numbers reference? I see 4 sets of numbers, two green and two red.

 
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Post by Jjones6840 » Sun. Oct. 14, 2018 4:16 pm

Both are internal temps, they need to be calibrated a little better. The red are actual temps while the green are setpoints. I have a draft induction fan that I added this year to help better control my heat output (keep it low and slow until thermostat calls for more heat) the one temp controller is a saftey for overtire ( don’t keep dumping forced air on the fire) and the other one shuts off the fan of my stack temps reach below 80 degrees ( idon’t want my induction fan to keep blowing if the thermostat calls for heat but I don’t have a fire lit

 
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Post by Lightning » Sun. Oct. 14, 2018 4:28 pm

Yeah, back to your original question 113 degrees for an internal stove pipe temp is pretty low.. How's yer fire doing? How far are the probes from the breech? Is there a barometric damper involved? Where are the probes in relation to the baro and stove? You have the safety high set at 1148? I don't think it'll ever get that high..

Where is the induction fan mounted? can I see a pic? It needs to blow under the fuel bed, mounted on the ash door would be the best place for it.


 
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Post by Lightning » Sun. Oct. 14, 2018 4:33 pm

Also, did you seal front and rear liners with fiberglass insulation so combustion air can't bypass from going up thru the grates? The first post of this thread here -

Clayton / Hot Blast Mods and Tending for Anthracite

 
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Post by Jjones6840 » Sun. Oct. 14, 2018 5:25 pm

The probes only go into the stove pipe about a quarter of an inch located between my Manuel pipe damper and thimble. My baro is fully shut now with .1 on scale (read directly before baro with brass tubing) but was at .5 when I originally asked this question. As for the induction fan, it appears to be coming in from below the fire (used the kit designed for the stove) and I sealed up the air intakes on the door with sheet metal. I haven’t got around to getting the fiberglass insulation yet. It’s hard to see in the photo, but there is small flame in the box now. Induction fan has been off since I light the stove this morning and spindown is a quarter turn open. Current outside ambient temp is 51 degrees and inside ambient temp is 79 ( I just opened windows started to sweat.)

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Post by Lightning » Sun. Oct. 14, 2018 5:46 pm

It's up to you of course but I would move the temp probes so they are in between the baro and stove. The reason is that whenever the baro opens (which will be variable) it will allow cooler room are into the pipe and influence your probe readings. This might also be why the 113 degree internal stove pipe temp seems too low to me. Your fire looks decent, fuel bed could be deeper from what I can tell, don't be afraid to fill it to the top of the fire bricks at every tending. Incoming combustion air will dictate heat output. I couldn't use the port on the back of my Clayton, which is very similar to your hotblast because it pushed air in over the fire, so make sure that's right (coming in underneath) or you'll just blow heat up the chimney with it. Also, you might need some secondary air in thru the load door for burning volatiles in the first phases of igniting a fresh batch. These stoves can be molded into an excellent anthracite burner if done right :)

One more thing, just keep the manual pipe damper open and let the baro control your draft. The baro will keep the stove steady between heat calls. PLUS if that induction fan comes on with the MPD closed, you could have a dangerous situation with the stove pressure going positive and spilling carbon monoxide into the room. So please, keep it open.

It's hard to tell from the pic but there appears to be a gap (could be a shadow?) where the flue pipe meets the thimble. You'll wanna seal that gap with fiberglass insulation also..

 
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Post by Jjones6840 » Sun. Oct. 14, 2018 6:07 pm

Great advise on moving the probes, make perfect sense to me, the picture of the coal bed is after 14 hours of burning so it’s about due to reload. I will remove one of my pieces of sheet metal to allow secondary air in( I just added those this morning). At the thimble I have high temp concrete around the stove pipe including everywhere two stovepipe sections meet and where the stove pipe meets the stove. As far as the MPD that only gets used when the stove is shut down or if there is an over fire or chimney fire(hasn’t happened yet hope it never will.) That came alone when I had a cast iron pot belly wood stove in the place of the furnace I opened the door and out came a bird. I will let the stove shut down add the fiberglass insulation and check on the induction fan while I am at it. This forum is awesome, and I’m not going to lie if it wasn’t for this forum I would have probably given up on coal and stuck with wood. I quickly learned they are not the same to tend. Thank you for your help!

 
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Post by Lightning » Sun. Oct. 14, 2018 6:48 pm

Jjones6840 wrote:
Sun. Oct. 14, 2018 6:07 pm
the picture of the coal bed is after 14 hours of burning so it’s about due to reload.
This time of year and in the spring while heat demand is low its not a problem to get 24 hour burns between tendings once its dialed in. I'm currently running 24 hour burn cycles. The key is to fill the fuel box to the top of the bricks, get the fresh batch burning well, and then close down the primary air to just a sliver. Then the challenge (for me anyways) is to keep a chimney draft, a little extra secondary air will help that also.

Jjones6840 wrote:
Sun. Oct. 14, 2018 6:07 pm
I will let the stove shut down add the fiberglass insulation and check on the induction fan while I am at it.
The main bone here is to seal the liners so that primary combustion air cannot take the path of least resistance behind the liners, keep that in mind when sealing them. And make sure you find where that induction fan is pushing air into the firebox.
Jjones6840 wrote:
Sun. Oct. 14, 2018 6:07 pm
This forum is awesome, and I’m not going to lie if it wasn’t for this forum I would have probably given up on coal and stuck with wood. I quickly learned they are not the same to tend.
I agree on both! I got a lot of positive encouragement from people around here and am eternally grateful. That, mixed with perseverance to get this handicapped furnace to burn anthracite made it all happen. Once you learn the burn, wood won't be so appealing ;)

 
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Post by Jjones6840 » Sun. Oct. 14, 2018 7:16 pm

The 12-24 hour burns was the most appealing to me. With oak or walnut I would get 4-6 hours between reloads. That ment getting off of work lighting the fire, reload before bed, wake up at 1 am to reload, reload before work, relight after work. I want to see the potential of coal this year with the mods. I attempted it last year with little luck and hope and got much higher heat out of the wood. I am coming in this year optimistic with coal as it seems to work great for everybody

 
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Post by Lightning » Sun. Oct. 14, 2018 7:40 pm

Oh you'll get there. One of the biggest stumbling blocks is clearing ash. You'll do good for a few days and then all of a sudden it'll be like, what happened? But don't worry, there are tricks for that.

Those mods will be HUGE for making anthracite successful in these units.

 
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Post by Jjones6840 » Sun. Oct. 14, 2018 7:44 pm

I watched one of the videos on this forum, it’s also in the plans to make some tools for clearing ash. Working 6 10 hour days until November and having a 2 year old makes time difficult for mods and tools, but they will be done this year to buy time later on.


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