Floor of Fire Box Around Underfeed Stoker

Stoker coal boilers and hot air furnaces and stoves using bituminous coal to heat your home or business. A stoker automatically feeds coal and combustion air
Post Reply
User avatar
Short Bus
Member
Posts: 510
Joined: Sun. Jan. 10, 2010 12:22 am
Stoker Coal Boiler: Kewanee boiler with Anchor stoker
Coal Size/Type: Chestnut / Sub-bituminous C
Other Heating: Propane wall furnace back up only
Location: Cantwell Alaska

Post Mon. Apr. 16, 2012 12:46 am

I have a Anchor stoker, similar to the Iron Fireman, and that generation of Bituminous stokers

The question after reading other posts, is how should I have built the floor of my fire box?

I set the stoker box on the floor, set the boiler base around it, filled with sand, and set fire brick in high temperature mortar to create a flat floor about one inch below the top of the tuyeres. Is there a better way to allow more room for clinkers or concentrate heat around the fresh coal?

We did this based on how my father saw it done in my grampas house, when they removed the wood fire grates and added a stoker to the furnace.
If it was as easy as burning oil, everybody would be burning coal.
Forum reality, If you ask wheres a good steak house? You will be informed that what you really want is pork chops.
Enjoy it for what it is worth.

User avatar
freetown fred
Member
Posts: 21426
Joined: Thu. Dec. 31, 2009 12:33 pm
Hand Fed Coal Stove: HITZER 50-93
Coal Size/Type: BLASCHAK Nut
Location: Freetown,NY 13803

Post Mon. Apr. 16, 2012 8:15 am

Just an old farmers thoughts, but, if it was good enough for your Grandpa ( common sense generation) It oughta be good enough for you--it's really not rocket science & you know that SB. ;) PS---plus, it sounds real good to me. :) ECONOMIC & EFFICIENT--oooh- rah
"A people that values it's privileges above it's principals, soon loses both"--Dwight D Eisenhower

User avatar
europachris
Member
Posts: 993
Joined: Sat. Dec. 09, 2006 5:54 pm
Stove/Furnace Make: EFM 350/Iron Fireman
Stove/Furnace Model: Custom bituminous burner
Location: N. Central Illinois

Post Mon. Apr. 16, 2012 8:57 am

That's pretty much how it's done. I have installation drawings from Will-Burt that show it this way, aside from using castable refractory cement rather than firebrick.

I used firebrick and refractory cement when I did my install and it worked out well. If I did it again I'd use the castable refractory because cutting and fitting the bricks was a royal PITA and a huge mess. It's just hard to find castable refractory and the firebricks were on sale at the local home center at the time.

The only reason that this installation method was developed is due to the nature of the stoker installs - i.e. converting hand-fed boilers and furnaces. Since the stoker had to go in through the ash pit, there was no place for an ash can underneath the unit. Due to the fortuitous quality of bituminous coal ash fusing relatively easily, it was possible to just let the ash accumulate, fuse into a clinker, and remove it through the firedoor.

Otherwise, for a "new design" stoker boiler, one could use something like the Prill rotating ring retort and set it up like all the other anthracite burning units and just have the ash fall into the can. I assume there would be a bit of carbon carryover into the ash with this type of stoker compared to the clinkering style, but unless it was a large (>15~20%) amount, the benefit of not having to let the fire cool, dig around for a red hot clinker and haul it out with tongs twice a day would outweigh the carbon loss.
Economic Stimulus = Supporting your local Miners
I love the smell of Illinois bituminous in the morning.
Have you hooked a clinker today?


User avatar
rockwood
Member
Posts: 1371
Joined: Sun. Sep. 21, 2008 7:37 pm
Hot Air Coal Stoker Furnace: Stokermatic coal furnace
Hand Fed Coal Stove: Rockwood Stoveworks Circulator
Baseburners & Antiques: Malleable/Monarch Range
Coal Size/Type: Soft coal: Lump and stoker (slack coal)
Location: Utah

Post Mon. Apr. 16, 2012 11:14 am

Shortbus,
I think you did the floor (hearth) right but the hearth around the tuyeres would usually slope up toward the walls of the combustion chamber. This does leave less space for clinkers but I believe it was done that way to keep the ash closer to the heat so there will be more clinkers formed instead of lots of ash just sitting on a flat hearth. A sloped hearth would help keep the fire hotter and there would be a less chance of unburned coal falling away from the fire.

I'm not saying you need to re-do the hearth but I think that's what they commonly did. If you just leave a sloping layer of ash and clinker you would achieve the same result.

Old furnaces/boilers would commonly have curved firebrick like this

Does your boiler have these?

How much space is there between the tuyeres and the wall?
"None are more hopelessly enslaved than those who falsely believe they are free." -Goethe

User avatar
Short Bus
Member
Posts: 510
Joined: Sun. Jan. 10, 2010 12:22 am
Stoker Coal Boiler: Kewanee boiler with Anchor stoker
Coal Size/Type: Chestnut / Sub-bituminous C
Other Heating: Propane wall furnace back up only
Location: Cantwell Alaska

Post Mon. Apr. 16, 2012 2:21 pm

Trust me I'm not changing my burner set up.
I think I have about 8 to 10 inches from the tuyeres to the boiler walls, my boiler is a vertical cylinder at this elevation, it is a Kewanee.
If I did it again I would probably slope the floor up gently, away from the tuyeres, but it is working fine.
If it was as easy as burning oil, everybody would be burning coal.
Forum reality, If you ask wheres a good steak house? You will be informed that what you really want is pork chops.
Enjoy it for what it is worth.

Post Reply

Return to “Coal Stokers Boilers & Hot Air Furnaces/Stoves Using Bituminous”