Minor Explosion In Coal Stove

Re: Minor Explosion In Coal Stove

PostBy: HarMark3500 On: Mon Jan 04, 2016 10:39 pm

SMITTY wrote:Been there, done that. Cracked the glass on the Harman Mark III I used to own! :lol: BOOOM! Shook the house with that one.

Always remember to NEVER feed air to a smoldering (no visible flame after loading) coal fire. Have both doors open, close ash door first, then SLOWLY close the top door, but ONLY after you see blue flame. ;) If you do that, it will never happen again.

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I'm still in the experimental stage with this stove. It has an automatic damper that opens when the thermostat calls for it. I though I had it down by letting more top air in. I was proven wrong.
HarMark3500
 
Hand Fed Coal Furnace: Harman SF-3500
Coal Size/Type: Nut/Stove

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Re: Minor Explosion In Coal Stove

PostBy: Lightning On: Mon Jan 04, 2016 11:04 pm

HarMark3500 wrote:I'm still in the experimental stage with this stove. It has an automatic damper that opens when the thermostat calls for it. I though I had it down by letting more top air in. I was proven wrong.


How do you let "top air" in?
Lightning
 
Hand Fed Coal Furnace: Overmodified/Bored out Clayton 1537
Coal Size/Type: Anthracite/Awesome Size

Re: Minor Explosion In Coal Stove

PostBy: HarMark3500 On: Mon Jan 04, 2016 11:08 pm

I have knows on the door. The manual says to open them about a quarter turn and that should be for most uses. I do that. But, when I re-load I open them about a turn oright so.
HarMark3500
 
Hand Fed Coal Furnace: Harman SF-3500
Coal Size/Type: Nut/Stove

Re: Minor Explosion In Coal Stove

PostBy: HarMark3500 On: Mon Jan 04, 2016 11:12 pm

Hers a pic
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HarMark3500
 
Hand Fed Coal Furnace: Harman SF-3500
Coal Size/Type: Nut/Stove

Re: Minor Explosion In Coal Stove

PostBy: Lightning On: Mon Jan 04, 2016 11:31 pm

Yeah thats not enough secondary air to keep the gases diluted until they are ready to safely ignite.

I prop my load door open a quarter inch till the blues ignite over the coal bed, let it burn that way for ten minutes, then seal the load door and allow some secondary air to burn the gases till the fire is established well. Then turn down the secondary air.

Some people may say it's too much mikey mousing around but that's how you get the most of the heat value from the volatiles after loading fresh coal. Secondary air needs to be adjusted to suit the amount of volatiles gassing off to use them most efficiently. Too much secondary air later in the burn just contributes to carrying heat out the chimney.
Lightning
 
Hand Fed Coal Furnace: Overmodified/Bored out Clayton 1537
Coal Size/Type: Anthracite/Awesome Size

Re: Minor Explosion In Coal Stove

PostBy: HarMark3500 On: Mon Jan 04, 2016 11:43 pm

I will give that a try, it makes sense. Besides the recent explosion thus thing has been great. It's in the basement and keeps the house at 74 degrees. 72 upstairs. I do burn some coal thought at 10 degrees outside.

One thing I wish this unit had is a glass door replacemnet. That would make it nice to see what's going g on without opening the door. I did get one or two puff backs to the face.
HarMark3500
 
Hand Fed Coal Furnace: Harman SF-3500
Coal Size/Type: Nut/Stove

Re: Minor Explosion In Coal Stove

PostBy: Lightning On: Tue Jan 05, 2016 4:30 am

HarMark3500 wrote:One thing I wish this unit had is a glass door replacemnet. That would make it nice to see what's going g on without opening the door. I did get one or two puff backs to the face.


It's not very difficult to install a window if you are up to it. A few of us Clayton/hotblast owners have done it. :)

Load Door Window Installation
Lightning
 
Hand Fed Coal Furnace: Overmodified/Bored out Clayton 1537
Coal Size/Type: Anthracite/Awesome Size

Re: Minor Explosion In Coal Stove

PostBy: Goozzez On: Mon Dec 05, 2016 2:55 pm

Hallo everybody!
I live in an old house in Belgium and yes, I still use coal to heat our 1908 house. Since a year we are having a new inox insulated chimney, but it pulls waaaaaaay to hard, so thanks to all your info i installed a barometric damper! Very good advice here!

But now i am experiencing another problem... When it's cold outside, now it's freezing, my stove burns with a lot of flames, so burining off the volatiles. But when refueling the stove, i have to open the top lid to fill up the hopper again with coal. When i open the top lid i always get an explosion or at least an ignition of the volatiles wich are stacking up in the hopper.

Is there anyone who can give me advice to prevent te ignition when opening the top lid of the stove?

Sorry for my bad english...

I have a Saey 92

thanx!
Goozzez
 
Hand Fed Coal Stove: saey 94

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Re: Minor Explosion In Coal Stove

PostBy: coaledsweat On: Mon Dec 05, 2016 3:30 pm

Bank the coal when you reload. The fresh coal is too deep, the fire is not burning the volitiles and they build up and boom.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: Minor Explosion In Coal Stove

PostBy: Goozzez On: Mon Dec 05, 2016 4:24 pm

Thanks for your advice!

The problem is there are flames in the coal that are on the grates, when i open the hopper lid before refuelling, then i get the ignition. Not that is is an enourmous explosion, but it burnt the hairs on my arms yesterday...

Today i tried to close the damper, so the chimey gets full pull, and slowly open the lid, then refuel and close the lid, adjusting te baro to original settings.
Goozzez
 
Hand Fed Coal Stove: saey 94

Re: Minor Explosion In Coal Stove

PostBy: Sunny Boy On: Mon Dec 05, 2016 4:34 pm

[quote="Goozzez"]Thanks for your advice!

The problem is there are flames in the coal that are on the grates, when i open the hopper lid before refuelling, then i get the ignition. Not that is is an enourmous explosion, but it burnt the hairs on my arms yesterday...

Today i tried to close the damper, so the chimey gets full pull, and slowly open the lid, then refuel and close the lid, adjusting te baro to original settings.[/quote]
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That's what I was going to suggest trying. By closing the primary air it might pull enough of the explosive fumes out of the hopper to prevent an explosion.

The antique stoves that use a magazine (which is the old-time equivalent of a hopper), have holes in the magazine all around the top, so that there is some circulation through the coal inside the magazine and the gases are diluted. Like gasoline (petrol) fumes they can only ignite when they reach a certain mixture of air and gas. Dilute that mixture with exhaust from the fire and no boom !

In similar fashion, fighter planes used to direct some of the engine exhaust into the fuel tanks to keep out air and prevent tracer bullets from blowing up the tanks.

Paul
Sunny Boy
 
Hand Fed Coal Boiler: Anthracite Industrial, domestic hot water heater
Baseburners & Antiques: Glenwood range 208, # 6 base heater, 2 Modern Oak 118.
Coal Size/Type: Nuts !
Other Heating: Oil &electric plenum furnace

Re: Minor Explosion In Coal Stove

PostBy: Serge On: Thu Dec 08, 2016 9:03 am

This happening to me before, the secret is to open the hopper door very very slowly.
Serge
 
Hand Fed Coal Stove: Hitzer 50-93, Hitzer 30-95, Hitzer 55ul
Coal Size/Type: Blaschak nuts

Re: Minor Explosion In Coal Stove

PostBy: Kaplanjc12 On: Tue Dec 13, 2016 10:39 am

Yesterday morning was wet and warmer. I filled up my (new to me this year) Alaska Kodiak Hand Fed with the normal bucket of nut coal, and then I added bit of extra chips and fines from my transfer bucket to fill it up the top of the fire brick. “Might as well burn it,” I thought. At first it looked like I may have smothered the fire, but when I did the same thing for the last few weeks, it always eventually came back. I had a "nice" mounded new coal blanket over the red coals and although I couldn’t see the red coals, I heard crackling and I opened the shaker/ash pan door to give it some extra air. About 30min later I shut the shaker ash/pan door and was about to leave for work when BOOOOM, the barometric damper disc shot out of its stove pipe tee and hit the wall about 5 feet from the stove. Scared the crap out of me. I immediately went into investigation mode…I never had anything like that happen before with my old Franco Belge, (but I only had burned coal 1 year prior). I imagined this happening again while I was at work and my dog stuck in the house!

The first thing I did after my assessment was search this forum. This thread in particular provided the info (and humor) I needed to understand where I messed up, and allowed me to leave for work with confidence that everything would be ok.

I filled her up this morning, leaving a small corner of orange glow. The blue ladies danced but forgot their fireworks.
Valuable Lesson learned…Thanks to all of you. :D
Kaplanjc12
 
Hand Fed Coal Stove: Alaska Kodiak no Hopper - (Franco Belge 144.08.02 - taking the season off)
Coal Size/Type: Nut

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