Seeking wisdom and suggestions from bit coal burners

When I was shopping for a bituminous stoker I spoke with Jason at Legend Manufacturing http://www.legendmfg.ca/order4.htm. He claimed their stoker would burn bituminous coal to an ash as opposed to most bit stokers which form clinkers and is available with an ash hopper and auger. I haven't actully seen this thing but it did sound interesting. steinkebunch has a thread in the bit section about this stoker as well. http://nepacrossroads.com/post34234.htm ... end#p34234

Terry

LsFarm wrote: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

Didn't the European made stoker boiler talked about a few months ago have a ceramic disk above the burn pot?

as was mentioned the use of a "brick arch" or ceramic disc etc. above the fire pot is a very good way to greatly increase combustion efficiency, and reduce smoke while not haveing to introduce addtional underfire air into the boiler. whether it could be made practical and durable in a small boiler, i'm not sure, but it's worth looking at.

I tried to turn come radiation back into my burn pot with a dew hunks of scrap steel

but it didn't work

Hi Sting,, suspend a full diameter steel disc about 4-5" above the fire so that it reflects all the radiant heat back down onto the fire.. It should make a difference,, what are you burning in there??

Greg L

That was straight corn 06-07 season

There are no mud legs in baby boiler -- so I was worried that a full reflection would insulate the radiation from the bottom of the vertical fire tube vessel and too much off at the refractory!

but then the burn chamber is big enough that I could stand some inch fire brick along the sides for extra thermal mass

Since i've never burned corn,, do you get unburnt or partially burnt kernels??
For burning bituminous coal, the idea behind reflecting the radiant back onto the top of the firebrick is to keep the coke and ash burning longer and hotter,, yielding a much more complete burn. Depending on the coal,, this may result in better clinker formation, or more ash/less clinker.

Greg L

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no partial combustion in my appliance - but the fuel varies from crop - field - season... You see the little bits on the scrap iron baffle - thats the non noncombustible portion of the seed shell - sometimes thats a heavy shell and sometimes lighter,

but I would like to be able to burn more volume of corn - well I did when it was 70 bucks a ton - I cannot get more than 2/3 feed capacity ( about 8 lbs and hour ) thru the burn process. I can get 12 lbs an hour of wood pellets but thats max and I have to use my largest burn pot. I found that moving the pot ( by modifying it and hanging it on the fuel / air flange upside down ) effectively gave me more BTU to my load on the same degree days - maybe that was the result of the reflection you have taught me about!

See - even if I am not burning coal - I am still tending a stoker/boiler and all you folks have been great to share your help with me!

There is no doubt that most Wyoming bit. coal will burn to ash rather than clinkers in most underfed stokers. Those that use the combusioneer/stokermatic stoves get a fluffy white ash. Some clinkers can form, but I think they are minor.

Another invention from Wyoming is a stoker called a "Prill". Attached is the patent document. If you look at Figures 3 and 5, you can see a mechanism that "spins" a ring around the firepot using the action of the feed auger. From what I understand, this moves ash and clinkers off.

There are still many of these stokers in operation today. I will see if I can get some photos. Maybe some learning could be gained from the Prill.

From the looks of it, the Prill and Combusioneer use tuyers that are VERY different from each other. I don't know the advantages of each.

And yes, I've talked to several Wyoming miners, and they can get at least 5 ton of bit. coal free each year as employees, depending on the mine.

Steinke in Wyoming

steinkebunch wrote:And yes, I've talked to several Wyoming miners, and they can get at least 5 ton of bit. coal free each year as employees, depending on the mine.

If something like this is successful and become popular that will probably change because a lot of them will take advantage of it.

I worked for a coal broker for 22 years supplying many of the indusrtirial stoker coal plants in NY & PA, most all of them have switched to nat. gas. The specs were usuallly mid vol 24-27, low sulfur -1.5% ash content -10% and one of the most important ash fusion temp. Fluid temp of 2700-2800 degrees. In Pennsylvania this narrows you down to the Upper and Lower Freeport seams also called D coal LF and E coal UF. Some plants went to 30%vol. but had to make adjustments to burn it. When a lower vol with high grindability is screened for stoker coal the ash ends up in the pea coal and the fines become cleaner, the oposite happens as the grindability goes lower. Clearfield Co, Cambria Co. Jefferson Co. Indiana Co. are the areas that make some of the coal of these specs. I had a friend who had a green house and he would save the broken glass and throw it on top of fire so it would melt and make it possible to take ash ring with tongs.