My New Furnace
i see a few issues with the design from the getgo if you plan on burning bituminious. if you are interested pm me, and I could give you a few tips on changing a few things before next season rolls around, or we could discuss it in open forum, if you wish.
sorry, I forgot about my post down here in the bitumionus section. here's a few things I noticed just from the pic; the grates are too narrow, the brick too steep, and the firebrick doesn't extend high enough. the width of the grates adn the incline of the firebrick MAY not be a problem if the coal you're burning is low or very low ash, less than 10%, for this reason I would reccomend not getting ROM coal even though it's cheaper but rather nut, possibly larger, egg may work as long as it doesn't clinker. I would highly reccomend extending the firebrick higher however, not because i'm worried about protecting the steel, but rather the heat needs to be kept in the coal bed to achieve a nice long burn time vs. opening the furnace finding a bunch of burned out coke, also if the heat is kept in the bed better you will have much less trouble with mid-phase bridgeing, rather in an evenly heated bed you will end up with short duration bridging followed by the coke cracking and shrinking allowing the coal bed to continue burning well without human interference. ideally you would also have some kind of brick arch or preheated secondary air directed at the top of the coal bed, this increases efficiency and helps alleviate "bridging". whether it's possible to easily incorporate any of these suggestions into your boiler; i'm not sure it depends on many factors, including your ability to wield etc.
If you need a good source of coal let me know via pm.
post more pics if you can, i'm interested to see the rest of the boiler. I sincerely hope for your sake that those are shaker/sliding grates.
If you need a good source of coal let me know via pm.
post more pics if you can, i'm interested to see the rest of the boiler. I sincerely hope for your sake that those are shaker/sliding grates.
Berlin,
Thanks for the reply I will take into consideration as to what you posted.
As to the type of coal I burn it is nut coal.There are pics of the coal I burn in the bituminous threads.I feel its pretty good qaulity coal it's always burned good for me.The stove I have is a pressurized unit it has a 135 gallon water jacket.The fire box is 44' long by 24 wide at it's widest point.It does have shaker grates in it also.I will try to post a few more pics.Thanks for the info.
Later RCI
Thanks for the reply I will take into consideration as to what you posted.
As to the type of coal I burn it is nut coal.There are pics of the coal I burn in the bituminous threads.I feel its pretty good qaulity coal it's always burned good for me.The stove I have is a pressurized unit it has a 135 gallon water jacket.The fire box is 44' long by 24 wide at it's widest point.It does have shaker grates in it also.I will try to post a few more pics.Thanks for the info.
Later RCI
- LsFarm
- Member
- Posts: 7383
- Joined: Sun. Nov. 20, 2005 8:02 pm
- Location: Michigan
- Stoker Coal Boiler: Axeman Anderson 260
- Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
- Baseburners & Antiques: Keystone 11, Art Garland
Hello RCI, I designed and built my boiler's firebox just like yours. This size and shape of firebox burns wood best, and is a compromise for burning coal.
Here is the problem. Coal needs a DEEP fire. The deeper the better. The area of the fire, in your case 44"x 24" will determine the maximum amount of heat available from coal. The depth of the coal bed will determine the duration of the burn. A 24"x24" fire will be about 200 to 250K BTU. So you do not need a coal bed that is almost twice this size.
What I did to make my boiler burn coal better was to block off the back half of the grate, I covered the grate with plate of steel that does not rest on the moving grates, allowing the front grates to operate freely. I then built a firebrick back wall at about the halfway point. I then used a few firebrick to raise the firebox threshold just inside the loading door. The end result was a square, MUCH deeper firebox that could be loaded up to 18" deep.
The tapered brick issue I was never able to solve completely, I did prop angled pieces of brick behind the tops of the brick to make them more vertical. The problem with the angled and tapered firebricks is they act like a funnel and cause the hot coal to slide down the slope, jamming together on top of the grates. The action of forcing hot coals together causes clinkers to form especially from Bituminous coal, very little from Anthracite. Making the sides of the firebox more vertical will help eliminate clinkers and ash removal problems.
If I were to build another hand fed coal boiler, I would build a square firebox. 2'x 2'x 2'. With the entire bottom composed of shaker grates. With vertical sides the coal would burn top to bottom without the coals compressing together. This is the way most good coal fireboxes are designed.
You will be able to burn coal in your boiler, but it will take some time and patience to figure out how to reduce clinker and reduce bridging.
I will attach a few photos of my firebox.
Hope this helps. Greg L.
.
Here is the problem. Coal needs a DEEP fire. The deeper the better. The area of the fire, in your case 44"x 24" will determine the maximum amount of heat available from coal. The depth of the coal bed will determine the duration of the burn. A 24"x24" fire will be about 200 to 250K BTU. So you do not need a coal bed that is almost twice this size.
What I did to make my boiler burn coal better was to block off the back half of the grate, I covered the grate with plate of steel that does not rest on the moving grates, allowing the front grates to operate freely. I then built a firebrick back wall at about the halfway point. I then used a few firebrick to raise the firebox threshold just inside the loading door. The end result was a square, MUCH deeper firebox that could be loaded up to 18" deep.
The tapered brick issue I was never able to solve completely, I did prop angled pieces of brick behind the tops of the brick to make them more vertical. The problem with the angled and tapered firebricks is they act like a funnel and cause the hot coal to slide down the slope, jamming together on top of the grates. The action of forcing hot coals together causes clinkers to form especially from Bituminous coal, very little from Anthracite. Making the sides of the firebox more vertical will help eliminate clinkers and ash removal problems.
If I were to build another hand fed coal boiler, I would build a square firebox. 2'x 2'x 2'. With the entire bottom composed of shaker grates. With vertical sides the coal would burn top to bottom without the coals compressing together. This is the way most good coal fireboxes are designed.
You will be able to burn coal in your boiler, but it will take some time and patience to figure out how to reduce clinker and reduce bridging.
I will attach a few photos of my firebox.
Hope this helps. Greg L.
.