Seeking wisdom and suggestions from bit coal burners

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The experimental stoker will use a pot similar to the pictured one, with a rotating head. The same pot can be used for a boiler or furnace.

Seeking suggestions from veteran users of bit coal so that we know what we might encounter with the burning characteristics of bit coal.

For instance, would the coal clinker and pull live coals into the ash pan?

The boilers have no horizontal surfaces to collect soot, but anthracite also produces ash dust, so I don't foresee any new problems there. The BTU rating of bit coal is slightly higher than anthracite, but we don't have a problem with burner plates burning out with anthracite. Some anthracite coal does clinker and that doesn't seem to be a current problem with our stoker.

Any suggestions would be helpful before we do the initial experiments.

most bituminous coal won't clinker and pull live coal into the ash pan, but it will form tars that will cause it to clump during burning and possibly fall off the pot (this is related to the coke button of the coal, the lower, the less likely it is to do this, most wv coals for instance have a high coke button) ideally the pot will be much broader for bit coal and allow the coal to burn a bit slower, which will reduce chances of clinkers. the big thing is allowing the use of coals that are large in size such as up to 2", this will allow most people to use bit nut coal which is easily obtainable.

I believe the pot is at least 22 inches wide and maybe 6 inches deep, which includes the ring of about 3 inches wide.

I am sure you have looked at the pictures I posted of my big Iron Fireman stoker...

There was no " ash pan" under

The under feed pot was under the level of the fire chamber floor. The floor was fire brick and the sides were the wet mud legs of the boiler vessel. The top of the combustion chamber was the bottom of the vessel. My Kewaunee was a double pass fire tube boiler - we didn't use turbulators when burning coal . Sometimes under hard burn the fire tubes would soot almost shut twice a day - but the were ez to punch with a scraper and brush.


The clinker formed and bloomed up and over, then laid along side the under feed pot. I had a long "bar" to reach in and lift/pry, the clinker so it would break into manageable pieces - and I have a clinker fork - Ill have to post a picture of one of the two remaining. I could reach in and grab the hot chunk - extract it out the fire door and pile it, to cool alongside the boiler. So there was some smoke off that hot clinker chunk, but that got sucked out via the baro damper and chimney draft - that might be a drama in an uncontrolled area like an open basement. I never shoveled and ash out - it all came out in clinger chunks. The only time the fire chamber was shoveled out was after spring shut down - when I got to go in and change out the busted fire brick along the floor and I recall one course sitting along the edge.

Even in the house where we had an Iron Fireman just like the one Greg fired before he switched to his AA

Nothing was "shoveled" out the bottom or out the door. All the "ash" came out as solid clinkers that we grabbed with the clinker fork and extracted out the door.

The was no ash pan

and the lack of an ashpan was the very reason noone liked those old setups, bit. coal can easily be burned w/ out clinkers. that's why firetubes are a bad idea.

No, I didn't see the pictures of the Iron Fireman. What is the link?

Here are a few photos of my Iron Fireman
this first photo shows a growing 'coke tree' in the burn pot.

I added a ring around the burn pot, hollow with air hole in the top surface to burn the coal longer and better.

The pot reminds me of the black pellets that turned into snakes with a match.

Berlin wrote:and the lack of an ashpan was the very reason noone liked those old setups, bit. coal can easily be burned w/ out clinkers. that's why firetubes are a bad idea.

HUH?????

Explain to me why fire tubes are a bad idea---

You would rather clean a water tube boiler????? - and do you also spend your free evenings carving your inner arm with a dull blade?

Whats more efficient and economical than a horizontal double or triple pass fire tube boiler ????

It's not a question of what's more efficient, it's a question of what sacrafice of efficiency is acceptable to achieve the desired result of clean and convenient use and operation. the ideal setup is a large boiler fire chamber with slow movement of gasses to obtain maximum heat transfer but with few baffles or other obstructions that require frequent cleaning. an example of an excellent yet simple boiler design is that of the keystoker boilers with two virtical baffles and a low flue outlet (not that efm isn't a terrific design as well, i'm just not familier with it).

btw, sting, i looked at your pm's and it looks like an intersting old stoker thanks for the pics, if you're interested in selling it i'll see if i can find someone for you that would be interested, of course i'd love to have it but i can't justify taking up any more space at my house with coal burning paraphernalia.

stokerman: thanks for posting the pic, looks like a nice setup using decently large auger tubes etc. I have two major concerns with the design; 1. the tuyers that are used with anthracite may not work well with bituminous due to the larger amount of fines present in the coal, basically most bit underfed stokers have tuyers that are almost virtical where the air enters the firepot, so that fines cannot fall into the underfire air passageways, alternately, there is actually a trap somewhat like an upside down P trap built into the tuyer casting such as on the iron fireman, this allows gravity to prevent fines from falling into the air passageways as well. 2. put a lip around the outside of the final ring of the firepot and under that lip have air come out to burn the coke trees that will invevitably form and fall aside from the main fire, also have this air supply separate in pressure and adjustment, thus allowing a clean, but lazy burning main pot, but an intense blast from arount the outer ring "lip" to burn chunks of coke. however all this may not be neccessary if a pile of ash is allowed to accumulate on the outer ring thus preventing coke trees from falling completely over and into the ash pan before being burned.

The pot of the efm has a sliding cover on the bottom to empty fines daily by pulling a lever. I don't know the meaning of tuyers, so I'm having a hard time understanding the post.

If you going to burn "bit" - and thats all the experience I have - your doing it to save money of fuel.

To me that says " I am willing to make extra efforts to get the last BTU out of every pound!"

So Ill punch fire tubes willingly and scoop powered soot with the shop vac running to abate the dust.

And I (read that me) would rather pick clinkers out of the pot than shovel and or pull an ash pan. I have an ash pan in my current appliance and its a pain. Dumping in the boiler room is a dusty mess - carrying it out doors tends to drip and there is the possibility of tripping with it and that associated drama!

Yes I know - the clinkers need to be shoveled off the floor and hauled out too, but thats a Saturday afternoon job and you can set up exhaust fans to control and evacuate that air born dust.

No I think ill stay a "clinker guy" for now.

One of the 'issues' with bitum coal is the wide variety of burning characteristics. I think the Wyoming Bitum coal will burn pretty well in and EFM stoker. It doesn't stick together and bridge, and it also won't grow 'coke trees' as easily.. The wyoming coal has similar burning characteristics to anthracite, but with lots of volitiles and soot.. The soot can be greatly reduced by adding extra fresh air over the top of the fire pot to burn off the volitiles..

By the way, the Tuyers are the perforated air grates surrounding the firepot. The Bituminous stokers did not have an ashpan. There was a wide [several inches at least] surrounding 'shelf' around the firepot, [usually made of refractory cement]. This is where the ash continued to burn and fuse together into clinkers,, then through an access door, clinker rakes and tongs were used to remove the clinkers. There was little loose ash.

This is very unlike anthracite where the loose ash just falls off the edge into the ashpan below.

What I think you will find with the first few tries at burning Bituminous, especially WestVirgina Bitum, and Western Penn. Bitum, is that the coal will create a lot of smoke and soot at first,, untill the water gets hot, which raises the temperature in the combustion chamber.
The coal will probably stick together, and make clumps of coke or partially burnt coal that will get tall and fall over.. As berlin suggested, a wider lip to let the chunks rest on to burn more completely would be helpful. I'm not sure that the rotating pot will be an asset or not, You may end up leaving the chain off the rotating drive.

Stoker man, what you really need to make an EFM for the Wyoming market is to get the Wyoming dealers to ship you a ton or so of Wyoming Bitumious coal,, Read the threads by 'steinkebunch' on the Bitum forum, his description of the wyoming coal may be helpfull I think you may be able to make a very good EFM boiler for Wyoming Bitum, but the various eastern Bitum coals... Illinois, both northern and southern,, West Virginia, and Western penn... all have different characteristics.. so this may take more time to develope.

I'd suggest getting a 1" tube set up with high pressure air, put something like a 'shower head' on the 1" pipe, and have this over the firepot.. when the fire is hot, but smoking a lot,, add extra air over the fire,, it should look like a blowtorch in the combustion chamber..

In many of the Bituminous-Stoker newspapers I have from the late 30's and early 40's, there were heat reflectors sold that were basicly a disc suspended over the firepot, maybe 8-12" above the fire. These reflectors were either steel or ceramic, and reflected the heat back down on the firepot,, increasing burn temps and helping create the fused clinkers to facilitate keeping the firechamber clean.. EFM may want to experiment with a plate of steel or ceramic suspended horizontally over the fire to keep the firepot temps higher..

Greg L

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