Keyman requests your help...

Keyman requests your help...

PostBy: keyman512us On: Sun Mar 11, 2007 4:48 am

Hello All!
I have a combustion question for the group. More importantly a heat transfer question I should say.
I have a Burnham SFB-101 coal/wood fired add on boiler (85,000 btu's/hr) ASTM rated, H-stamp, the whole nine yards. I have been using it for three seasons now to "heat" the house... Because of the age of the unit...no info is available from Burnham. A 'google search' on this particular model will re-direct you to the forum. Nobody has ever heard of this particular model. For what I paid for it...it is worth it's weight in scrap alone...but it produces beautifull heat you can't beat. Design wise it is fairly decent... Because of "limitations" at the homestead...operation inside the house is not feasible ("yet") so it is "outdoors"...not optimal...but functional. With a wood-fire it really cranks out heat fast. With coal it does "allright" but I'm looking to 'fine tune' it's operation.
That's where the forum members come into the picture: Below I'm going to post two pictures...I want your "technical opinions" because here is what I'm thinking. Above the fire are 3-inch wide removable steel plates to create a "smoke shelf" I figure for wood operation. Do you think they should be "pulled out" for coal use? Perhaps straight up heat transfer to the firetubes (2.5"-16 total)?
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Flue exit height at top...2" above top of firetubes.
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Smokebox view of "shelf" and firetubes
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keyman512us
 

PostBy: keyman512us On: Sun Mar 11, 2007 5:11 am

My second question relates to "under fire" air. The underfire is a "natural draft" that can be increased by a honeywell chain operated damper lifting the "mailbox slot" lid on the lower door. On the inside of the door...there is a small metal "restrictor plate" held on by two screws. Do you think it might/should be removed to allow more "underfire" air for coal use?
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"Mailbox slot" style damper on lower door
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Inside door view of the mailbox flap. Notice the "factory set" underfire air allowed by the square
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keyman512us
 

PostBy: keyman512us On: Sun Mar 11, 2007 5:21 am

My third question...
When I finally get everything "down pat"...where would you install a barometric damper (if needed to fine tune the draft) above the T (see first post above or below...install an "add on" where the clean-out cap is presently?

It may be outdoors...but I can "play with/fine tune" this baby without worrying about the house being affected...
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15' "Custom Stack" 20' discharge height
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Bottom to top view at clean-out
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PostBy: keyman512us On: Sun Mar 11, 2007 5:29 am

In case you are wondering about the above pictures: "Why the home-made job" with the "stove pipe"...why not insulated stainless steel???"

What you are looking at is for all intents and purposes "insulated" but active. You can't see the "inner workings"...It is something I have been working on for the last year to reduce smoke and emissions for wood firing...(very important in my neighborhood)...between coal and this stack...the neighbors are "off my back" and "semi-happy"(as much as can be expected anyway)...I'm looking into a patent application as we speak.
keyman512us
 

PostBy: coaledsweat On: Sun Mar 11, 2007 9:20 am

Do you have the Installation and Operating Manual for the unit? If not I can shoot you a copy. I almost bought one of those back in the mid '90s. I actually ordered it, only to find out it was discontinued about 2 weeks before the order was placed. It is a good hand fired unit, the only thing I didn't like is it lacks a combustion blower. But it appears to have a pretty massive air channel at the damper to the grates so that is probably a moot point. I understand the Honeywell draft regulator works very well on these units.
The baffles are removable for cleaning, you can remove them for coal. They will tend to get flyash accumulating on them if you run them with coal. Their purpose is to lengthen the residence time of the heat before leaving the stove. If you remove them you will lose efficiency. Yours look tattered, I would replace them with new stock.
The book says that a baro is optional if fired on coal only, however I would not run anthracite without a baro myself. They want -0.05 draft @ the breech.
The damper should have orifice hole in the center, this supplys the air for low fire and MUST NEVER be covered or altered (their bold). Do you have a pic of the damper door closed?
When I first started burning coal, I had no idea what I was doing and didn't have this site to help. Since I'm addicted to print anyway, I just called about every manufacturer of coal burning equipment to send me their manuals since the one that came with my Steel King boiler was missing the "good stuff". Most manuals are pretty good, but almost all of them seem to lack something and that just makes the puzzle harder for us.

I hope this helps.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

PostBy: LsFarm On: Sun Mar 11, 2007 10:07 am

Ian, did you ever get a manual for my 1930's IronFireman underfeed stoker?? :) :lol: .

Seriously though, do you have a manual for any underfeed stoker?? Like a Will-Burt?? My stoker unit has several settings for air both in the auger feed-tube, and above the auger in the retort, and it is pure guessing for me to adjust these settings.

Keyman, I think those flat deflector plates should stay in place, not only do the slow down the gasses heading up into the heat exchanger tubes, but the plates also reflect heat back down onto the coal bed, this helps make the coal fire more efficient.

I have several old trade magazines from the 30's-40's and there are ads for refractory panels that were mounted above the coal fire to reflect heat back onto the top of the fire, and to deflect and slow the exit of the burnt gasses.

So I'd leave the plates in place.

To get more heat from coal, you need more air, so I would remove the restrictor plate and try burning with full available air. The worst is that you reinstall the restrictor.

You may want to try a combustion blower, they definitely wake up a fire. The flames in my hand load fire went from 1-3" to 8-10" when the fan was running. But of course the coal burnt-up faster too.

Combustion fans are fairly reasonable in cost, mine is an AC-16, do a google search for that and I think you will find it, if not PM me and I'll try to find more info. I think they were about $58 each. I can't remember right now who I bought it from, sorry.

Experiment with larger/smaller size coal to get hotter/cooler fires. Stove size coal with a layer of nut over the top gave me the best results, but my firebox is not the same as yours, each design is different and likes different things.

Keeping the grate clean enough to get air to all the coal bed was an issue with my grate, I didn't design it very well for coalburning. Keep an eye on your coal bed for dark, or slow burning spots, you may have areas that are not burning at optimum.

Keeping your vertical heat exchanger tubes clean will help a lot with the efficiency of the boiler. Does the top of the exchanger come off so you can clean the tubes from top to bottom?? If so, set up a monthly schedule to run a wirebrush on a extension through the tubes. Keeping the insulating layer of ash to a minimum will really help.

Hope this helps, Greg L

.
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

PostBy: coaledsweat On: Sun Mar 11, 2007 10:44 am

I've got the E-F-M (boiler & stoker) and Axeman manuals, everything else is hand fired I think. It's been years, I'll check the library.

I don't think you'll need a blower on the Burnham, that draft port is HUGE!
Last edited by coaledsweat on Sun Mar 11, 2007 11:18 am, edited 2 times in total.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

PostBy: LsFarm On: Sun Mar 11, 2007 10:53 am

But you should see the fire with forced combustion air!! Like you said, probably not necessary.

Here is a link to some info on the AC-16 blower I used in my boiler as the main combustion blower, and use now as a continous combustion air blower for my stoker.

It has a nice mounting flange, and has a off-low-high speed switch.

http://www.englandsstoveworks.com/manua ... ctions.pdf

Greg L.

.
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

PostBy: Charlie Z On: Sun Mar 11, 2007 7:51 pm

greg,

That blower looks like you could fab a duct to cold air supply from that squirrel cage...?

- Charlie
Charlie Z
 
Stove/Furnace Make: Coalbrookdale
Stove/Furnace Model: Darby

PostBy: LsFarm On: Sun Mar 11, 2007 8:28 pm

Hi Charlie, you could, but there would be no way to have a movable flap over the fan inlet to control the volume of air. If you made a large tube to fit over the outside diameter of the fan instead of to the inlet size maybe...

I think just a piece of 2" PVC that had one end outside and the other end about 3-5" away from the fan inlet would suffice, the area of the fan inlet not covered by the flapper is rarely larger than the area of the 2" pipe.

Just a screen over the outside end to keep critters out, should do it.
LsFarm
 
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

PostBy: keyman512us On: Mon Mar 12, 2007 5:39 pm

Ian, Unfortunately, I don't have an owners manual...which is why I asked if anyone had any info. You're right about the Honeywell damper, it works great! Wood fired this baby cranks out the heat and is everything you could ever hope for. Coal is "leaving something to be desired" but I'm getting better at coal firing. The only "problem" with stove sized coal with this unit is it needs to be blended with smaller sizes just right or it will go out.
The restrictor shelf is a "little ratty" due mostly to rather hot wood fires.
Ian, Do you remember off-hand what you were quoted for a price for one of these Burnham SFB's back in the 90's (if you don't mind me asking)?
keyman512us
 

PostBy: coaledsweat On: Mon Mar 12, 2007 8:10 pm

I think it was around $3,400, I can't recall because it was about 12 years ago. I'll ask the salesman if he can remember, he might even have some literature. I'll make a copy of the manual for you, just shoot me a PM and I'll get it out in the mail. For a hand fired manual I must say it is detailed and has a lot of info that relate to most coal units/chimneys/oper.

You probably want to run nut in that thing unless you need a lot of heat out of it. That stove coal is hungry for air.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

PostBy: keyman512us On: Tue Mar 13, 2007 7:01 am

Thanks to everybody...
Greg I am considering trying the blower idea...making it capable of becoming "like a forge"...There is 110AC available at the boiler, along with aquastat control...could substitute the blower in place of the honeywell damper control..I'm handy with the 'electrical end'...just happy with the potential of loading it full and getting a long burn out of it...perhaps for "warmer weather applications". Right now I can only get 130 degrees continious out of it...I have a feeling my "smokestack" is holding the draft at the point where the natural 'underfire' air is limited. I'm going to look into getting an accurate draft measurement...all things considered I'm glad I'm not fighting "too much heat".
Ian, I took a couple snapshots of the underfire damper:
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Damper closed showing "factory air opening" coin is a quarter to show scale
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Close-up of "closed setting"
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keyman512us
 

PostBy: keyman512us On: Tue Mar 13, 2007 7:09 am

I have a feeling the draft is being held back by the smokestack...here comes "Revision #4"...lol I just went out fifteen minutes ago and checked the fire...continious circulation of jacket water to inside accumulator tank and "radiant barrel" jacket water @ 112 degrees fairly good fire going...getting a nice long burn so all is well...at least it is manageable!

Her is a pic from last night getting stove coal to burn:
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Firebox half loaded with stove sized coal
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keyman512us
 

PostBy: coaledsweat On: Tue Mar 13, 2007 7:50 am

FILL the firebox right to the TOP of the firebrick, even when you don't need a lot of heat. That may be why you have a low draft, your boiler has no coal in it. Burning coal is like growing corn, it only works well when there is a lot of it. That boiler should have no trouble running 160-200* F water. Filling the firebox doesn't burn more coal, but it will be happier, more efficient and easier to control with less chance of upset. When it gets colder you can even mound it up in the center for a longer harder burn.
I would not be in a hurry to add a blower to that until you get a handle on running it. What is the rating on your oil/gas/? boiler now? If it is 100,000-110,000 BTUs you won't need a blower at all. The old timers will tell you that a natural draft is best, as the blower blows your heat up the chimney when running. It will however give you better recovery and increase total BTU output, but eat more coal. Be conservative with changes, coal is sneaky, and is slow to react.
Lucky you, I just found the old catalog (yeah I save all the crap w/coal) that has the #s the salesman gave me. It was $3,040 + freight new. They actually made two versions. The add on that you have and a combo coal/oil unit with an optional tankless coil for hot water. IIRC it was an additional $1080. I will copy the catalog page and send it out with the manual today.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

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