How to not get backfire in stove!

How to not get backfire in stove!

PostBy: ridgeracing On: Thu Jan 10, 2013 10:05 pm

After reading about coal stove explotions on this forum-here are my findings. After burning coal for the past 2 months at different high and low settings, burning coal well below hopper and into fire bed (36hrs). I have always just loaded coal completly over top and never a cough and within seconds had blue flames.
I am looking for everyones opinion, but here is why I believe I have never had an explosion.
After burning 12-24hrs-
1- MPD is closed 95%, dont open, has not been opened since I started coal stove!
2- Shake stove for about 10 seconds, not touching anything else on stove!
3- I fill by coal bucket up, slowly open hopper door (to quick and smoke may come out) and fill hopper.
4- Open ash door and may shake 2-4 seconds till I see glow and small red coals fall, close or empty tray (2-3 days till full)
5- Top off hopper and close lid
6- Blue flames are always there or there within seconds. (On a 36hr+ burn and re-filled with 60-80lbs of coal, blues were there within a minute)

In my opinion, the reason I may not be getting any backfires is that I keep a tight draft and by keeping MPD mainly closed I am not PULLING gases to strong threw coal bed while loading and re-igniting at a large amount. I have also found that while loading and after I see blues that if I open frt door blue flames start to die down within seconds, like blowing them out? Dont no if this make sense to anyone, but stove works great and have never had a hick-up!
Just looking for other coal jumkies thoughts! :roll:
ridgeracing
 
Hand Fed Coal Stove: DS Machine Stove
Stove/Furnace Make: D.S Machine
Stove/Furnace Model: DS1600WH

Re: How to not get backfire in stove!

PostBy: tcalo On: Thu Jan 10, 2013 10:40 pm

Just confused on one thing, do you leave the mpd closed when you open up the stove to reload? If so then wouldn't you get gases and co in the house!
tcalo
 
Hand Fed Coal Stove: Chubby Coal Stove
Coal Size/Type: Nut Anthracite

Re: How to not get backfire in stove!

PostBy: franco b On: Thu Jan 10, 2013 10:47 pm

The difference in your stove is the hopper which supplies some coal which is already coke and the rest is hot and ready to burn.

If in a batch loading stove a large amount of cold coal is loaded at once the conditions for generating gasses faster than they can be burned are much greater.
franco b
 
Hand Fed Coal Stove: V ermont Castings 2310, Franco Belge 262
Baseburners & Antiques: Glenwood Modern Oak 114
Coal Size/Type: nut and pea

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Re: How to not get backfire in stove!

PostBy: ridgeracing On: Thu Jan 10, 2013 10:49 pm

I never open MPD! I only have hopper lid open for 5 seconds while I fill it up, I might see a small puff of fumes come out for just a second. Dosent smell like sulfer or anything, Co never goes off
ridgeracing
 
Hand Fed Coal Stove: DS Machine Stove
Stove/Furnace Make: D.S Machine
Stove/Furnace Model: DS1600WH

Re: How to not get backfire in stove!

PostBy: Lightning On: Thu Jan 10, 2013 10:56 pm

When you reload, do you leave a corner of the burning coal bed exposed? or is it completely covered? I'm not sold on the MPD being the cure for no puff backs. Seems like you would let some coal exhaust into the room by keeping it closed during loading. I agree, by keeping it closed the coal doesn't really get to crank up much, reducing gas off from the fresh coal.

I'm more apt to think that somehow you have sufficient secondary air to keep the gases off the fresh coal to number 1 - keep burning or number 2 - keep them diluted to the point that they can't flash. The sufficient secondary air could be coming up from the under the coal bed, if you have some really clean nut (no fines) AND have cleared most of the ash away OR it could be coming in thru the load door gasket, if thats not sealing tight OR (lol) back to what I started with, you leave a corner of burning coal exposed so that there is always a flame available for gases to ignite from instead of building up in the firbox :D
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut Size / White Ash

Re: How to not get backfire in stove!

PostBy: ridgeracing On: Thu Jan 10, 2013 10:59 pm

franco b wrote:The difference in your stove is the hopper which supplies some coal which is already coke and the rest is hot and ready to burn.

If in a batch loading stove a large amount of cold coal is loaded at once the conditions for generating gasses faster than they can be burned are much greater.

I believe that helps to, but I have reloaded with nothing in hopper and low coal bed, 3-4in of fresh coal on red coals + full hopper.
Maybe the fresh air holes in frt of fire bed (top) help? Maybe thats a DS MACHINE thing?
ridgeracing
 
Hand Fed Coal Stove: DS Machine Stove
Stove/Furnace Make: D.S Machine
Stove/Furnace Model: DS1600WH

Re: How to not get backfire in stove!

PostBy: Lightning On: Thu Jan 10, 2013 11:01 pm

ridgeracing wrote:Maybe the fresh air holes in frt of fire bed (top) help? Maybe thats a DS MACHINE thing?


Houston, we have the answer..... :lol:
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut Size / White Ash

Re: How to not get backfire in stove!

PostBy: ridgeracing On: Thu Jan 10, 2013 11:09 pm

[quote="Lightning"]When you reload, do you leave a corner of the burning coal bed exposed? or is it completely covered? I'm not sold on the MPD being the cure for no puff backs. Seems like you would let some coal exhaust into the room by keeping it closed during loading. I agree, by keeping it closed the coal doesn't really get to crank up much, reducing gas off from the fresh coal.

Yes, most of the time I reload it there is a corner that there is still an open red coal etc. to re-ignite. But I have reloaded it with nothing but black coal covering it 2-3in deep.
I no its hard to believe, but loading it from top with dampner closed I really dont get much smoke/fumes threw top. I open it slowly and get a small puff,thats it.
ridgeracing
 
Hand Fed Coal Stove: DS Machine Stove
Stove/Furnace Make: D.S Machine
Stove/Furnace Model: DS1600WH

Re: How to not get backfire in stove!

PostBy: MarkV On: Thu Jan 10, 2013 11:46 pm

[quote="ridgeracing"].
After burning 12-24hrs-
1- MPD is closed 95%, dont open, has not been opened since I started coal stove!
2- Shake stove for about 10 seconds, not touching anything else on stove!
3- I fill by coal bucket up, slowly open hopper door (to quick and smoke may come out) and fill hopper.
4- Open ash door and may shake 2-4 seconds till I see glow and small red coals fall, close or empty tray (2-3 days till full)
5- Top off hopper and close lid
6- Blue flames are always there or there within seconds. (On a 36hr+ burn and re-filled with 60-80lbs of coal, blues were there within a minute)

Ridge, do you close the hopper lid after filling hopper in step 3? Then re-open hopper lid in step 5?

Or do you leave it the hopper lid open while shaking in step 4, and then close in step 5?
MarkV
 
Hand Fed Coal Stove: DS Machine DS-1500WH
Coal Size/Type: Blaschak bulk nut

Re: How to not get backfire in stove!

PostBy: buck24 On: Fri Jan 11, 2013 1:23 am

I.m old school and was taught to open the MPD all the way when shaking down and loading or recharging the fire. Then when she's burning good and the blue ladies are dancing you can set your air intake slots for your draft and then adjust your MPD to 3/4 closed or where you want it to be. A lot of the fine ash may have a tendancy to build up in the stovepipe when shaking down with the MPD closed. I always keep mine open when shaking and reloading. I'd like to see what some of the other members say.
buck24
 
Hand Fed Coal Stove: New Buck Corp. / MODEL 24 COAL
Coal Size/Type: Pea, Nut / Anthracite

Re: How to not get backfire in stove!

PostBy: tcalo On: Fri Jan 11, 2013 2:19 am

Stoves and setups are different but fundamentals of operation are all the same. Good reasons to open the mpd during reload and shake down are to allow volatile gases and fly ash to exit out the flue rather than build up in the stove. I reload my stove in layers and crack the secondary air purges to help burn off volatiles and shorten the recovery. It also helps me to avoid the big bang!
tcalo
 
Hand Fed Coal Stove: Chubby Coal Stove
Coal Size/Type: Nut Anthracite

Re: How to not get backfire in stove!

PostBy: Beeman On: Fri Jan 11, 2013 5:47 am

I am totally with Buck24 and Tcalo--I always keep MPD open while shaking ashes and loading coal. Always have some open flames available to light volatiles. Once new coal and fire have settled in, I close MPD 3/4 of the way. Be careful up there in E-town!
Beeman
 
Stove/Furnace Make: Hitzer
Stove/Furnace Model: 503

Re: How to not get backfire in stove!

PostBy: I'm On Fire On: Fri Jan 11, 2013 11:43 am

Every stove and setup is different.

OP, your techniques do not work and have not worked on my stove (DS Machines 1600)as they have yours. What I found to work on my stove has been opening the MPD 100% then cracking the glass door, shaking, reloading then waiting 15-20 minutes for the blue flames. Then closing the MPD and glass door.

BUT since adding these: Image all I do now is open the MPD 100%, shake and then wait 5 minutes and close the MPD 100%. Haven't had an explosion since installing them.
I'm On Fire
 
Hand Fed Coal Stove: DS Machines DS-1600 Hot Air Circulator

Re: How to not get backfire in stove!

PostBy: franco b On: Fri Jan 11, 2013 11:55 am

When you cracked the glass door it was the same thing as slowing the air through the coal bed which generated gas at a slower rate and with less velocity of air which allowed it to burn in a more controlled manner.
franco b
 
Hand Fed Coal Stove: V ermont Castings 2310, Franco Belge 262
Baseburners & Antiques: Glenwood Modern Oak 114
Coal Size/Type: nut and pea

Re: How to not get backfire in stove!

PostBy: I'm On Fire On: Fri Jan 11, 2013 1:18 pm

franco b wrote:When you cracked the glass door it was the same thing as slowing the air through the coal bed which generated gas at a slower rate and with less velocity of air which allowed it to burn in a more controlled manner.


Yup I was going to order the glass door with the over-fire spinner knobs but the louvers I installed last weekend have really helped and I don't think I'll be buying the other door.
I'm On Fire
 
Hand Fed Coal Stove: DS Machines DS-1600 Hot Air Circulator

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