Questions on Soft (Ohio) Coal

Around here soft coal is about 100 dollars cheaper a ton than anthracite, due to shipping costs. I have a USStove wood/coal furnace, and I was thinking of getting some soft coal, but im not sure I know about all of its properties. I guess what I am wondering is there a way to burn it cleanly? And my furnace will hold roughly 100 pounds of coal at a time, with a coal bed 6 to 8 inches thick. How would the heat output and burntimes compare with anthracite? I am also worried of our flue blocking quickly due to soot buildup. Maybe someone here could clue me in on it. The only reason why I had bought some anthracite was so I didn't have to get up in the middle of the night to stoke the fire with more wood when its COLD out. Any input would be great. What burntime would I see with a good amount of heat on output?

You should let us know where you are, and it would help knowing more about the coal you are burning. Some Bituminous has a similar BTU output to Anthracite. If it was really poor quality maybe 50-60% of Anthracite, and an average around 80%.

I would think that the burn time would run fairy relative to the BTU output.

Im in north central ohio, my neighbor goes down south to get it. Last year I think he paid 50 a ton then he is going to charge me for the drive. Can't get you an exact location of the coal. I have burnt lump coal from ohio, and it was very dirty and produced a hell of alot of soot. This coal is stoker or nut size coal.

My father tried burning some Indiana soft coal many years ago in a Woodchuck add-on furnace, likely similar to yours. We also burned some in a German Weso tile stove.

While it did burn long and put out impressive heat, it also clogged the chimney in a matter of weeks and turned everything around it black. It really was a disaster. The Weso seemed to burn it more cleanly, but it was really designed as an anthracite/wood stove.

The key to burning bituminous is to control the speed of the release of all the volatiles, and then get them both hot enough and mixed with enough air to burn without making soot. I really think this stove:http://www.dunsleyheat.co.uk/techyork.htm would be the ticket for burning bituminous relatively cleanly. But, they are not imported to the USA, as far as I know (at least not when I enquired some years ago).

[Edit:] The Yorkshire stove is also about US$2200 list price at current exchange rates, LESS shipping to the US. That's a lot of $$.

Chris

Thats quite a nice stove! A bit pricey but I bet it does the job. My neighbor burns the coal I wanted to get and he says he burns the soot from the chimney. Someday he will burn his house down also.

I burn Anthracite and Bituminous coal. What coaledsweat said is correct. The various Bituminous coals all are different.

The Bituminouos coal I had last year was horrible. It had pieces of stone, tons of ash, lots of volitiles [tons of smoke and soot], high swelling index, and a low AFT. A low AFT [ash fusion temperature] means that the ash would melt together into a rough sheet of glass/ash/stone. This 'clinker' would seal off the grate, and stop air flow, putting out the fire. This happened every three days!! I would have to shovel out the ash, unburnt coal and the huge 9"x16" clinker. [see photo].

This year I have some much better Bituminous coal. It has a lot less soot and smoke [lower volitiles], a bit less ash, no stone or rock. higher AFT, but a high swelling index.

The high swelling index means that when I add a layer of fresh coal, when it heats up, it swells and sticks together into a big sheet of coal. This can create a sheet from side to side of the firebox. This 'bridges' the fire below and leaves a big gap under the bridge. If I'm home, after about an hour, I go and break up the bridge with a strong heavy poker. Once the sheet is broken up, it stays in separate pieces.

So, depending on your source, you can get coal that burns very similar to anthracite, or have a miserable pile of black, lumpy frustration. I would highly recommend trying to burn a sample of any Bituminouos you are considering purchasing in quantity.

You can reduce the soot in the chimney by using your above-the-fire secondary air. This added air will burn off some of the gas from the volitiles. Some secondary air will help burn up any bridging coal. But you will probably get much more smoke and soot coming out the loading door as you load in fresh coal. I used several pre-filled buckets to rapidly dump in 40-60# of coal and quickly close the door. The volitiles start to gas-ff very quickly and the chimney can't draw all of them up fast enough to keep all of it inside the firebox, some is bound to get out the loading door.

The length of burn will vary, but it will usually burn as long as Anthracite. But nowhere near as trouble free. When I burn just antheracite, It is just dump it on, and shake it down, and let it burn. No smoke or soot out the door, just some noise as the coal heats up. [snap, crackle and pop]

Hope this answers most of your questions. Greg

The other photo is of a typical bituminous initial flame: yellow and sooty. The bituminous is a shovel-full of coal in the back of the pile. The coal in front is anthracite.

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That klinker was why I purchased some anthracite coal. I've heard of good soft coal and bad. I'll have to further check into it before I decide to get a set amount. I know the lump coal burned like wood. Anyone know the proper amount of lump coal for an overnight burn? This stuff is a good 4 to 6 inch chunks.

don't worry about the flue blocking, the soot will periodically blow out, especially when during violent ignition of secondary burn. although it is best to never use less than an eight inch pipe at any point; and a T cleanout is desireable for flue inspection at least monthly while burning to insure no excessive buildup (i usually brush my chimney once midseason after around 3/4" buildup of "fluff") it is possible to burn soft coal fairly clean with the correct amount of air for secondary burn, preferably preheated; however high and mid vol bituminous coals will still produce smoke, don't worry about it, there is nothing you can do.

btw, where did you get the "lump" coal, that is very hard to find, i would like to take a ride to the mine when i go through ohio next time.

I got it in lodi. This man was advertising last year and it was 90 a ton. I wan't sure about it, and really I was worried about burning both the soft coal and wood. Not knowing what the both would do to the chimney and flue. Also I was looking for an overnight and not sure if lump was the way to go. This man gets it by 15 or 20 ton bulk, then delivers it. That price was 90 a ton delivered. Should have bought more, Im not sure if he sells it this year or not.

if it burns well you should definately get more. 90/ton is a little steep, but being lump which is hard to obtain and including delivery is not too bad.

I burn nothing but soft ( bituminous ) coal in both my AHS boiler and my little Harmon Mark II. It takes a different technique than burning anthracite. If the coal you are talking about is just lumps it will most likely get enough air through it and burn o.k. If it has a lot of fines in it you can not just simply but a 4"thick bed in the stove and hope it burns. It needs air, and plenty of it. I usually fill it with a thick bed when refilling, wait for about an hour or so, and then poke a hole right in the middle of the bed. The hole has to be completley through the bed to the fresh air underneath.
If you have a combustion blower under your grates the air will be forced up through the hole and will look almost like a blast furnace. The coal will eventaully burn from the hole outward over time.

I have really good results with the method and can usually get a 10-12 hour burn without any further tending, If the hole is done correctly..
Then I just shake the snot out of it until I have just red hot coals on the bottom and repeat the process...

As others have said though, alot of your sucess will depend on the quality of the soft coal.. If you take a look at it, you want it to be as shiny as possible. Not all of it will be shiny but a good portion of it should be shiny. If not, it isn't going to burn very well... ( Just my opinion )

I wouldn't worry much about it blocking the chimney, If you have an 8" chimney you should be good to go. I only have a 6"on my Harmon and still never had a problem. Burning coal is way less hazardous, in my opinion, than burning wood, No creosote.. I have never even known anyone that had a chimney issue burning coal...

Shawn.