Hopper Fire - Alaska Channing 3 with direct vent

PostBy: JerseyCoal On: Sat Mar 17, 2007 6:10 pm

I just had a revelation! There is no need for me to suffer the unbearable emotional burden of "stove envy" any longer. Thanks to OUR LEADER making this forum available to us, it was determined several weeks ago that all stoker owners are "girlie men" and that real men shovel and shake.

So what if I'm overweight, balding and have no money. I find my self-esteem in the fact that I operate a hand-fired coal burner! Take that all you girlie stoker guys!
JerseyCoal
 
Hand Fed Coal Stove: Franco Belge model 10.1475

PostBy: coaledsweat On: Sat Mar 17, 2007 7:34 pm

Stove envy, I like that. Can you imagine the shrinks at the next symposium or whatever they do? :)
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

PostBy: ohiocoalburner On: Sat Mar 17, 2007 10:13 pm

Yes my Hitzer uses a similar type of hopper and the fire will burn up to the bottom of the hopper, but no higher. The manual tells you that after filling the hopper to make sure that no coal is left on the lip before reinstalling the cover or the fire will travel into the hopper. I always check mine and have never had a problem yet. Also no hopper use with bituminous coal.
ohiocoalburner
 


PostBy: gaw On: Sun Mar 18, 2007 8:44 am

Wow, there must be something in the air. I have a Keystoker boiler that had a fire back to the bottom of the hopper earlier this winter. It seams the crap I first used to seal the grates hardened, shrank and cracked and eventually failed allowing air from the blower to be forced through.
At the time I spoke to someone at Keystoker about it and they are very emphatic about not having too much draft. They want a .02 draft over fire and no more. It sounds counterintuitive but they insist that high draft causes the fire to travel back to the hopper. Because I had run for weeks without any problems and no adjustments and have verified the draft with a draft gauge several times in the past and when I told them it was an old used stoker I had taken apart and put back together they suggested looking at the grate sealant. When I took the grates apart the cement I had used just fell off. This confirmed to me the suspicion and after getting some fresh cement at Lowes and cleaning and reassembling the grates it has been burning flawlessly ever since.

I know this info is specific to the Keystoker boiler and may or may not be relevant to other makes of stokers.

One more thing, I asked Keystoker what the worst case scenario would be of a hopper fire that happened with no one there to find it and they were reluctant to speculate about it but I think it does not take much imagination to figure that one out. Be careful!
gaw
 
Stoker Coal Boiler: Keystoker KA-6
Coal Size/Type: Rice from Schuylkill County

PostBy: traderfjp On: Sun Mar 18, 2007 4:36 pm

I don't think there is a problem with hopper fires if you keep an eye on the level of coal in the hopper. But we all live busy lives and we shouldn't have to depend on our memories to prevent a hopper fire.
traderfjp
 
Stove/Furnace Make: Alaska
Stove/Furnace Model: Channing 3

PostBy: Matthaus On: Sun Mar 18, 2007 4:51 pm

Matthaus wrote:
The usual blah blah blah.


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Edit: I edited the image link so it displays, you can display images inline by first pasting the image URL, hightlight the URL then hit the box labled IMG which will wrap the the highlighted text with the correct bb code. It will look like this without the *'s.

[*img]http://nepacrossroads.com/files/stove1a_445.jpg[*/img]

"Your Leader" :lol:
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Thanks Richard! Another example of how I learn something on this forum every day! :lol:
Matthaus
 
Stoker Coal Boiler: Leisure Line WL110 Dual Fuel, natural gas
Hot Air Coal Stoker Stove: Leisure Line Lil' Heater (rental house)
Coal Size/Type: Rice and Buckwheat Anthracite

PostBy: Richard S. On: Sun Mar 18, 2007 5:13 pm

traderfjp wrote:we shouldn't have to depend on our memories to prevent a hopper fire.


Defnitely a new advantage I've found to having a auger feed. The fire would have to travel through about 10 feet of steel pipe to get to the hopper which of course is not going to happen.

As I said in an earlier post this is the first itme I've heard of this, I don't think it's a common occurence.
Richard S.
 
Stoker Coal Boiler: Van Wert VA1200
Coal Size/Type: Buckwheat/Anthracite

PostBy: traderfjp On: Sun Mar 18, 2007 5:27 pm

No disrepect to the admin but I believe that in my stove I would have a hopper fire 10 out of 10 tries if I let the hopper go low. While it may not be common it's still an issue of safety and with some ingenuity a solution could easily be obtained. Even a sensor on the hopper to turn off the electrical current would be a start. I just hope it's not like the intersection without a light and we need a trajedy to put that light in.
traderfjp
 
Stove/Furnace Make: Alaska
Stove/Furnace Model: Channing 3

PostBy: Richard S. On: Sun Mar 18, 2007 5:40 pm

traderfjp wrote:No disrepect to the admin


You're banned, no disagreeing with the admin allowed. :twisted:

Seriously though I would never consider it direspectful or anything along those lines for someone expressing their opinion... I mentioned in another thread even if someone came on here totally against coal I wouldn't censor their posts providing they weren't being a PITA.

Rest assured no offense is taken from anything anyone has to say.

I will agree it is a very big safety concern if simply forgetting to do something could cause this and it wouldn't be something i would take lightly if I was in your position. My only point is that I've never heard of this happening, not saying it can't happen or didn't happen it's just never come to my attention.
Richard S.
 
Stoker Coal Boiler: Van Wert VA1200
Coal Size/Type: Buckwheat/Anthracite

PostBy: Matthaus On: Sun Mar 18, 2007 6:11 pm

traderfjp wrote: Wouldn't a baro also allow a vent into the room if the outside section of my powervent ever clogged?


Now I realize we are talking apples and oranges. Your direct vent is basically a pressurized exhaust since the power unit is on the back of the stove. Of course you are correct a baro damper cannot be installed on this kind of system. My unit pulls the products of combustion from the stove and yours basically pushes it.

Based on how you described your installation I think you may not be getting a good enough draft on the stove. If it were me I would definately check the draft jon the stove side of the power vent and also check the static pressure of the stove. I still feel that the hopper fires you are assured of by running the hopper low is not per the original design intent of the stove, more investigation is required before accepting this as a unchangeable situation.

I would also install an overtemp interrupt in the bottom of the hopper near the rear and wire the stoker power through it just to be on the safe side. This link gives the catalog cut sheet for a fenwal unit (~ $35) that is adjustable and can be mounted to the out side of the hopper in an electrical box to safely allow for wire connections.

http://www.flowfactor.com/Merchant2/gra ... /30000.pdf

As you said there is no reason to leave things to chance when your safety is at stake.
Matthaus
 
Stoker Coal Boiler: Leisure Line WL110 Dual Fuel, natural gas
Hot Air Coal Stoker Stove: Leisure Line Lil' Heater (rental house)
Coal Size/Type: Rice and Buckwheat Anthracite

PostBy: LsFarm On: Tue Mar 20, 2007 10:42 am

I let my LeisureLine Pioneer run out of coal. The fire stops several inches from the hopper feed opening. There is a shallow layer of unburnt coal on the feeder block or shovel. None of this coal is burnt.

There is plenty of coal hanging on the edge of the hopper feed opening, and no indication of any burning near or in the hopper.

This is all with virtually zero draft, take a look at my hack-job 'temporary' chimney. [it's been 'temporary for two years :oops: ] Quote from Yanche: nothing is more perminant than a functioning temporary fix.

I think the LeisureLine design block combustion air with their shovel design, the fire is stopping several inches from the hopper. Even with zero draft, I feel very comfortable with letting the hopper run out of coal in this stove.

Greg L
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You can see unburnt coal on the pusher shovel, and see where the burning coal stopped.
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The hopper feed opening, empty except for a few stray pieces, and no indication of burning
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My hack-job chimney, once it makes the turn at the top the flue ends.
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LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

PostBy: LsFarm On: Tue Mar 20, 2007 10:51 am

A better view of my 'temporarily perminant' chimney. This side of the barn faces east, so any easterly wind actually creates a slight positive pressure in the flue.

This chimney was created to vent the red Waste-Oil burner you see behind the coal stove.

You can see the rust stains on the hopper from the condensation, again from inadequate draft.

But I don't have any indication of a hopper fire.

Greg L
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The open end of the flue is about 10' below the roof peak. I can't imagine a worse chimney.
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LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

PostBy: traderfjp On: Tue Mar 20, 2007 12:47 pm

LSFarm: I don't understand-if you let your stove run out of coal why is there coal on the grate? When my stove runs out of coal an opening occurs between the grate and the hopper. I also have a power vent which is a different type of vent then yours which may be part of the problem.
traderfjp
 
Stove/Furnace Make: Alaska
Stove/Furnace Model: Channing 3

PostBy: LsFarm On: Tue Mar 20, 2007 1:18 pm

Hi Trader, the design of the LL pusher block is a flat piece of steel about 1/8" thick with another thicker piece of steel on top of it, making a step. The unburnt coal you see is resting on the 1/8" thick piece of the pusher or shovel. This section of the pusher shovel is about 2.5-3" deep from the step out to the leading edge that nudges the coal fire on every stroke.

Normally the pusher block would have about 1.5-2" of coal on it, what you see is a single layer of coal pieces, only about 1/2" of coal, there is a 1.5" gap from the ash over the top of the pusher into the hopper opening. I could put a 5" long piece of 2x4 on the pusher, and it would show through the hopper feed opening, and show just infront of the burnt ash.

As the pusher is moved in and out, the the thicker step is just below the hopper opening, the block pulls back, some coal falls into the recess, but onto top of the 1/8" thick section, the back and forth motion sort of pumps the loose coal forward out onto the grate.

The air holes for combustion start just underneath the pile of ash you see in the photo, the unburnt coal is sitting on the pusher shovel. So the design keeps the fire several inches in front of the hopper opening, and unless the cover was left off the hopper, I can see no way that draft and or air could backup through the hopper opening and into the hopper.

I haven't looked closely at the Alaska 'pusher-paddle' design, but it sounds like it has the combustion much closer to the hopper feed opening. Maybe not, but from the problem you had it is the only way I can see a fire getting back into the hopper. Maybe the gasket at the top of the cast iron grate is bad and lots of combustion air is blowing through the coal very close to the hopper opening?? Don't know.

I posted these photos to show what I had commented about early in this thread. My hack-job, dangerous, temporary chimney is still not allowing a hopper fire in my LL Pioneer stove, and it has every excuse to have a hopper fire.

I can see your concern, I think an over-the-fire draft check is in order, you want to make sure your venting motor and fan are very clean and pulling a good draft through the stove, providing a negative pressure on the whole unit. If I were you, I'd want the draft to suck the hopper cover down tight!!

Greg L.

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Last edited by LsFarm on Tue Mar 20, 2007 7:04 pm, edited 1 time in total.
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

PostBy: reicharb On: Tue Mar 20, 2007 2:22 pm

Has anyone seen this happen with a Harmon Magnum?
reicharb
 
Stove/Furnace Make: Harmon Magnum ST8-VF8