Strange...White Dust and Clinkers

So I just got a new batch of coal (Reading Rice) and my stove started acting up. Well we had a mild weekend so I shut it down and cleaned everything out and then re-lit it. The same problem was still there. Here's what's going on...

The entire inside of the stove is covered in white dust. When I say white, I don't mean light colored, I mean literally it's as white as my car is painted and completely covered. When I open the door, there white smoke everywhere and it's quite smelly. I can't put my finger on the odor, but there's pretty much no sulfur smell that I have noticed, but a total "what is that burning" smell. In addition to the white dust, it's not feeding pretty much at all. I don't think the feeding is related to the coal as much as the clinkers and dam that's building on the grate. It seems that the coal is really fusing together and creating just a solid dam on the grate that I have to scrape off with a pry bar. Has anybody had this and can enlighten me on what's going on?

A little bit more information...I've always used Reading Rice coal because there's a dealer less than a mile from my house so that's still the same. The only thing that was different in this batch was the fact that the truck bed had some salt in it before we loaded it up. We did shovel it all out and the amount of salt left in the bed was minimal...seemingly negligible in comparison to what's going on. I did dig out a good bit of the hopper this morning and replaced it with some old coal bags I had previously to see if it fixes the problem. One thing I noticed when I shut it down was a little speed bump of coal pretty much fused to the carpet side of the grate. I scraped it up and assumed it was the problem, but the problem came right back after lighting it.

Pat

Might be poor quality coal, but before we point the finger at Reading try reducing the combustion air slightly. Excessive fly ash and clinkers is often the result of too much air.

I would agree with Rob that the combustion air may need to be adjusted. IT could be a result of cleaning the grate holes now allowing more air or it could be a difference in coal in this load. I know I sometimes have to make small adjustments on my combustion fan restrictor plate depending on where the coal came from.

Do you keep the combustion fan running all the time or does it only run during "pilot" mode or a call for heat?

The fact that the coal is fusing together on the grate, that sounds like Bituminous coal, or really young anthracite coal that is almost Bituminous.

Anthracite coal will not clinker untill around 2500*-2700* and it doesn't sound like you are burning that hot.. And an anthracite clinker on a bed=type stoker
is a soft easlly crushed 'cake' of partially stuck together ash. NOT a hard crust that requires tools to remove..

So go buy 4-5 Bags of Blaschak coal, empty the hopper and run nothing but Blaschak for a day or two.

If my suspicions are correct that " Reading coal" is mixed Bit coal in with the Anthracite, or your dealer is bagging Bit coal and representing it as Anthracite.

DO NOT BURN BITUMINOUS coal in your flat bed stoker,, it is a recipe for a hopper fire and CO poisoning !!

I'd send that 'Reading coal' back and buy from a good source,

Be safe, make sure your CO detectors are workng, and get some different coal.

Greg L

Was this Reading Coal bagged and shipped on a pallet from Reading's bagging operation?

Or is the dealer bagging some bulk he had purchased?

The coal was bought in bulk. It must be bad coal because I switched over to my Reading bags this morning to see how it affected the burn and much to my surprise, it was burning the correct way again. The coal has something wrong with it and I'm not sure what the difference is, but I was burning bulk a month ago also from the same supplier. I'm not sure what their turnover is, but I'm guessing that they must have turned their whole bin over in that time...I didn't think there were that many coal burners in Pittsburgh though.

Is there a way to determine if it is bituminous? Or is there a way to determine the percentage of bituminous? it looks pretty much the same as what's in the bags to me.

Bit coal smokes a LOT when first heated, Anthracite just pops and crackles. And it gets soft when heated, and swells and sticks together. Since your coal has this swelling and sticking on the grate characteristic, to me, it's Bit coal.

But you can try this: get your stoker bed going with a good big anthracite coal fire, at least 4-5" of the bed burning red.. Take a hand full of the suspect coal and lay a 1/2" layer over the hot fire.use a coal shovel or a BBQ spatula, be careful.
if it is Antracite, it will just pop and crackle [wear goggles] and catch fire. hte fire will be a clean white to blue fire
If it is Bit coal it will smoke with a yellow gray smoke,then burn with a dirty oily yellow fire then change to a normal red bed of coals.

The problem is not the smoke, it is the fact that is swells and glues itself together, that alone makes it unusable in your stoker

Take it back, and get actual coal bagged at the breaker, not bagged from 'mystery coal' in you retailer's yard..

If you do this test, take photos, I did this test with known Bit coal once,, and it was a spectacular fire when the bit smoke ignited !! Be ready!!

Greg L

LsFarm wrote:Bit coal smokes a LOT when first heated, Anthracite just pops and crackles. And it gets soft when heated, and swells and sticks together. Since your coal has this swelling and sticking on the grate characteristic, to me, it's Bit coal.

But you can try this: get your stoker bed going with a good big anthracite coal fire, at least 4-5" of the bed burning red.. Take a hand full of the suspect coal and lay a 1/2" layer over the hot fire.use a coal shovel or a BBQ spatula, be careful.
if it is Antracite, it will just pop and crackle [wear goggles] and catch fire. hte fire will be a clean white to blue fire
If it is Bit coal it will smoke with a yellow gray smoke,then burn with a dirty oily yellow fire then change to a normal red bed of coals.

The problem is not the smoke, it is the fact that is swells and glues itself together, that alone makes it unusable in your stoker

Take it back, and get actual coal bagged at the breaker, not bagged from 'mystery coal' in you retailer's yard..

If you do this test, take photos, I did this test with known Bit coal once,, and it was a spectacular fire when the bit smoke ignited !! Be ready!!

Greg L

Okay, so I tried this test. I think I might have executed it wrong though because I turned my combustion air back on and after reading your post, I'm tempted to believe it should've been left off when you said that it will turn to a red bed of coals. Anyway, what I saw was a mixed bag of both. I saw the coal crackle and pop like antracite, but it immediately was smoking an enormous amount and the flame was yellow the whole time. It never turned back to blue'ish until the coal being pushed in from the hopper started lighting as you could tell because the blue was only on the rear of the grate.

I'll try again tomorrow with the bags and the bulk to see if the behavoir is different. On another note though, my brother took half of a ton from this last trip and now he's having a similar issue. He left for a little while today and came home to find his house at 64 degrees and a coal dam built up and preventing new coal from being pushed onto the grate.

I've never had issues with clickers, smoke and/or white dust so something's changed. I've been burning coal for about 5 years now so I'm pretty sure that something's changed in the batch I just bought. I'm thinking that Reading is cutting the anthracite with bituminous and I might have got a mixture that's out of their spec.

It does sound like some bit is mixed in with the ant. You mentioned you bought in bulk, does that mean you got a loader scoop from your suppliers bin? The poor mixture could have occurred from him changing storage bins or an employee dumping product in the wrong bin or if he was at the bottom of the bin and scooping stuff from the ground that was "contraband" from who knows where or when.

I stopped getting coal from one dealer around here, they didn't have concrete or blacktop pads and they wouldn't scoop from the middle of the pile, but would scrape the ground picking up crusher run with the coal. The guy i buy from now has concrete pads to scoop coal from and has real clean product.

Pconn, you definitely have Bituminous coal.. I don't think Reading is cutting their coal, it's your retailer, either like mentioned above, an honest mistake or the retailer may be trying to sell an $80/ton product as a $160/ton product.. And you and your brother are seeing the results.

PLEASE don't burn this stuff, you could have CO leaks into the house and that can be deadly.. I hope you both have working CO detectors in the house.

Your test was positive and definitive for Bituminous.. you could see the difference when the real anthracite came out of the hopper following the dose of Bit you put on the grate/fire.

So I'd find a different retailer, or get them to give you good coal.. The stuff they sold you last is NOT ANTHRACITE COAL.. and is potentialy dangerous in your stoker stove.

Please let us know how this works out.

Greg L

Sorry to let you know that the bulk coal mixed with the salt is causing the white all over the inside of your burner box.

The white residue is the incomplete burning of the volitiles in the Bit coal.. NOTHING but Bit coal fuses together and requires tools to remove it from the grate.. the white residue is not the problem, it's a symptom, the problem is that the coal is fusing on the grate and causing the stove to not feed or burn properly.

I have burnt Bit coal in a stoker as an experiment,, it did EXACTLY what this coal is doing..

It's dangerous, take the coal back, get real anthracite to burn in your stoker stove.

Greg L

I have burned rock salt in a soft coal boiler and it does turn everything very white...but like others have said that's not your problem...just a coincedence

Alright...I've spoken with the supplier. He claims that the salt will lower the ash fusing temperature, thus causing the clinkers and clogging of the grate I'm seeing. I've since bought more bags and once again, the problems are not there. So I've decided to dig deeper into my bin where the coal wasn't exposed to the salt and once again, I'm still getting the clinkers, but no white smoke. I'm not sure what this means at this point other than the white smoke is in fact related to the salt, but the coal is still crap. I'm very upset because I've bought over 30 tons from this supplier and now I'm looking for a new supplier because of one ton that he doens't want to take back. I think the coal is either being cut by bituminous or there's something wrong with it. I don't think it's bitiminous, or at least all of it. It seems to still burn okay and right now I'm mixing the two, but I can always tell when it's crossing the grate because my propane furnace kicks on as I need to go downstairs and pull the ashes off of the grate so that the thing can start making heat again.

My new motto...eff Reading. Their craftsmanship is poor as my doors leak terribly, and now I'm having issues with their coal. They really need to step up their quality. They market their big stove as a furnace because it has a large blower on it, but they don't realize that much of what makes a furnace different from a stove is that a furnace have any radiant heat. I guess you live and you learn.

Thanks for the update, The average AFT of anthracite is around 2500-2700*, average AFT for Bituminous 1600-2000*..
so his comment about salt is just BS,, and even if it's true,, the coal is still NO GOOD..

There have been threads on this forum about anthracite coal creating 'ash dams' on flat bed stoker grates, but they are soft, like a cake. and push off
with a gloved finger or a touch of a poker. And this only happens when the stoker is burning at maximum heat with too much air.

Your build up on the grate: you said takes tools to remove/scrape to clean off the grate.. Well this is NOT anthracite.. it's Bit coal.. Anthracite build up would crumble like cake

I had a flatbed stoker and put some Bit through it just to experiment, and it did exactly as you describe, the coal got soft and gooey, stuck together, made a dam on the grate, and it took a scraper and hammer to remove the mess. and it smoked and stunk.. the inside of the stove was grey-white.

PLEASE be careful when burning up this bad coal !! MAKE SURE your CO detectors are working !! and DON'T fill the hopper with this stuff, only mix it so you can get rid of it,, or sell it to someone with a Combustioneer or Stoker matic, that burns Bit coal.

Greg L