Convert Central Boiler Furnace to Coal?

oakscreek · Post by **oakscreek** » Sat. Feb. 28, 2015 8:09 pm

We have a central boiler classic cl7260 dual fuel outdoor wood furnace. It's oil or wood for fuel choices, we use wood exclusively with it. It's 500,000 BTU and used to heat a 3000 sf greenhouse and a 1500 sf house in addition to hot water. We use 4 ten wheeler loads of logs each winter, but don't want to cut and split that much wood anymore. Can we convert this to burn coal and if so, what are recommendations on how and most economical way to do it?

McGiever · Post by **McGiever** » Sat. Feb. 28, 2015 8:14 pm

Welcome oakscreek

Where you located?...fill in your profile.

You want to burn Bituminous or Anthracite?

oakscreek · Post by **oakscreek** » Sat. Feb. 28, 2015 8:24 pm

We are located in upstate N.Y.

We are open to recommendations as to which to burn. Just starting our research.

oliver power · Post by **oliver power** » Sat. Feb. 28, 2015 8:46 pm

All I can say is WOW! And Welcome............. We have some good, qualified boiler men on the site. Be patient, they'll be along.

Post by **Rob R.** » Sat. Feb. 28, 2015 9:01 pm

Plan on selling the OWB and replacing it with a stoker boiler. The OWB doesn't have shaker grates, or even an ash pit to install a conversion stoker in.

Give a lot of thought into how you will handle the coal and ash.

oakscreek · Post by **oakscreek** » Sat. Feb. 28, 2015 9:53 pm

Thanks Rob, but we can't sell it. It's a 2003 and no longer meets emission standards.

Post by **coaledsweat** » Sat. Feb. 28, 2015 10:11 pm

oakscreek wrote:Thanks Rob, but we can't sell it. It's a 2003 and no longer meets emission standards.

Since you are not a manufacturer, why do you think you need to meet an emission standard? It's used, sell it as such.

oliver power · Post by **oliver power** » Sat. Feb. 28, 2015 10:40 pm

coaledsweat wrote:
oakscreek wrote:Thanks Rob, but we can't sell it. It's a 2003 and no longer meets emission standards.
Since you are not a manufacturer, why do you think you need to meet an emission standard? It's used, sell it as such.

My thoughts as well.........

lzaharis · Post by **lzaharis** » Sun. Mar. 01, 2015 12:33 am

oakscreek wrote:We are located in upstate N.Y.

We are open to recommendations as to which to burn. Just starting our research.

================================================================================================

Lots to do before you can come to a conclusion.

If your going through four loads of logs a year, its 20 full cords plus.

What can you afford?

Freight on coal is expensive, fifty dollars a ton to Ithaca from Tamaqua, Pa.for example
and would be more for soft coal from the Pittsburg area mines.

Any soft Bituminous coal unless its metallurgical coal from Buffalo Fuels and others will have a lower BTU value.

The other thing is that you will be hard pressed to find a soft coal stoker that will
burn cleanly and IT WILL piss off the wrong people and your neighbors as the sulphur
odor and fly ash will drift along way.

With the amount of fuel wood you burn it may be better to have a carload of anthracite
shipped by rail to Ithaca and have it unloaded on the siding there as they have a railcar
unloader( a carhoe) and have it trucked from Ithaca to your green house/business establishment.

The firm that hauled coal from the siding in Ithaca to the steam plant at Cornell University
"Mix Brothers" is very well versed in doing this and they are still actively hauling materials.

Their office is just outside Freeville near route 13 North.

You may need to plumb several stokers in series to meet your heat demand.

Your depreciation schedule will be another issue.

Do you have oxygen barrier pex in the ground?, thats a must have pretty
much because of the temperatures at which they operate.

4. can you safely plan on having a tri-axle or trailer load of coal brought
to the location where the wood boiler is now?

Do you have a pole barn where you could put the stoker and a
pile of coal inside it.

Ideally a four inch Westfield grain auger from Cummings and Bricker
with a factory installed drive unit and plastic feed hopper would be best to
make the coal loading job into the boiler hopper or hoppers easier.

Saying that a good portable grain cart either stationary or on wheels (depending on your set up)
with the side dumping chute would work well to feed the auger or augers as the coal would flow freely (if it
was oiled into the augers hopper).

a. oiled or non oiled coal? oiled coal is best for most pusher plate stokers as it reduces rust to a
minimum in the hopper walls and reduces fugitive coal dust.
Some stokers use oiled coal(keystoker) and some do not axeman anderson, AHS, Leisureline..

b. do you have place where you could dump a load and keep it
undercover to reduce ice and water buildup?

Are the pumps in a warm air space/basement or mounted on the Central Boiler?
You will not be able to leave them exposed to the elements as the stokers have no way
to shield them from the cold like an insulation blanket on an OWB..

ANY stoker you choose will have less water capacity than the central boiler unit so you may want to consider additional pressurized hot water storage. Weben makes good stone lined hot water tanks our first one lasted 30 years (you just have to be sure to change the sacrificial anode every few years.

I probably forgot something and will get yelled at for mentioning hot water storage but a green house heated with a hot water radiator/modine heater is no different than a commercial laundry that needs hot water at all times.

Berlin · Post by **Berlin** » Sun. Mar. 01, 2015 1:51 am

lzaharis wrote:
Any soft Bituminous coal unless its metallurgical coal from Buffalo Fuels and others will have a lower BTU value.

The other thing is that you will be hard pressed to find a soft coal stoker that will
burn cleanly and IT WILL piss off the wrong people and your neighbors as the sulphur
odor and fly ash will drift along way.

None of this is true. Met coal is the last thing you'd want to burn in a stoker as it's high agglommerating tendency / coke button makes it a terrible choice; most eastern bituminous coals beat anthracite's btu/lb and have a lower ash %, not just met coal. Soft coal stokers can burn soft coal very cleanly in a residential setting. There is virtually no smoke, smell, or fly ash emission.

However, anthracite coal and coal burning equipment is BY FAR the most plentiful and commonplace in the northeast and upstate NY. Burning anything else takes a bit of understanding extra work that most are unwilling to do when anthracite coal and equipment is plentiful. You should really be looking for an anthracite stoker boiler as others have advised.

Pacowy · Post by **Pacowy** » Sun. Mar. 01, 2015 2:25 am

The big front door area on that unit looks like it could accommodate a fire door, stoker mount and ash door/ash removal. I would be most concerned with protecting the coal supply against the elements so it feeds properly, and also protecting the stoker mechanism. Some type of enclosure "in front of" the unit is almost certain to be needed.

Anthracite stokers are available in an assortment of sizes and configurations, especially if you would consider used equipment. It shouldn't be too hard to come up with options.

I would be very careful about planning to use oiled coal. The Keystoker manuals I have seen specify use of dry coal. Other mfgrs may allow lightly oiled coal, but the air holes in many stoker grates are susceptible to clogging with oiled fines, and with an outdoor unit it's probably best to avoid running it in a way that may tend to require frequent maintenance.

With $50/ton trucking you can put reasonable anthracite in the bin at a price equivalent to FO under $1.10/gallon. It's hard to imagine circumstances where an individual user could make sense out of buying a rail carload, since you still have to pay the railroad, the logistics of prompt unloading and local trucking add headaches and costs, and you need to have the financial resources and space to buy and store 100+ tons at a time. I know a guy who burns a lot of coal and owns a business that routinely receives bulk commodity shipments by rail. He takes his coal by the TL.

Good luck.

Mike

windyhill4.2 · Post by **windyhill4.2** » Sun. Mar. 01, 2015 7:58 am

oakscreek , WELCOME to the coal forum. Are there pics available of the innards of that boiler ? I could not find anything online. That OWB looks huge, we had one that was rated for 600,000 BTU & it didn't look as big. Ours only had 200 gallon water storage.

Hambden Bob · Post by **Hambden Bob** » Sun. Mar. 01, 2015 9:24 am

Welcome To The Coal Board,OaksCreek ! As You are already seeing,The Caring Folks Here Are Always Willing To "Go Deep" To Give You Views And Perspectives !! Take Your Time,wade and sift through the Info that's coming to You,and then Vector In on a Path that's Financially and Practical,Tactical that will fit Your Business and Living needs......Don't let Your Head get too Bogged Down,just relax,figure out what You truly need,and then,Trust Me,You'll also want to use Our Vast Reserve Of Archived Information to Learn More ! It's all in the upper right corner of the page,and it's known as Our In-House "Google Custom Search" bar......I like Your situation...You already have the End-User Hydronic System in place,and are looking at being able to either Modify,or Replace the Classic....Some Food For Thought: If You've had the Classic burning wood since 2003 or 2004,to my understanding those water tubes only last so long before You start Springing Leaks. This has been the Experience of some Folks that I've known in Our Area(N.E.Ohio)......You may want to figure that in before You start putting Good Money into that Unit.....Just A Thought..............

lzaharis · Post by **lzaharis** » Sun. Mar. 01, 2015 10:12 am

Berlin wrote:
lzaharis wrote:
Any soft Bituminous coal unless its metallurgical coal from
Buffalo Fuels and others will have a lower BTU value.

The other thing is that you will be hard pressed to find a soft
coal stoker that will burn cleanly and IT WILL piss off the
wrong people and your neighbors as the sulphur odor and
fly ash will drift along way.

None of this is true. Met coal is the last thing you'd want to burn in a stoker as it's high agglommerating tendency / coke button makes it a terrible choice; most eastern bituminous coals beat anthracite's btu/lb and have a lower ash %, not just met coal. Soft coal stokers can burn soft coal very cleanly in a residential setting. There is virtually no smoke, smell, or fly ash emission.

However, anthracite coal and coal burning equipment is BY FAR the most plentiful and commonplace in the northeast and upstate NY. Burning anything else takes a bit of understanding extra work that most are unwilling to do when anthracite coal and equipment is plentiful. You should really be looking for an anthracite stoker boiler as others have advised.

==================================================================================================
When I had the pleasure of meeting Oilman and Don Somers, one of the owners of
Keystoker at Wilkins Coal last year he told us-being the folks at the meet and greet
that Saturday that they recommend oiled coal for their boilers and furnaces to
prevent rusting in the coal hoppers .

It was certainly nice of them to cart along a KAA-4-1 boiler after my asking them
about bringing one to look at and to see the KAA-4-1 boiler they brought rather
than having only the brochure to look at.

I am only listing the coal portion of the fuel comparison per the 1993 ASHRAE handbook:

Firewood/fuel comparisons
comment
Coals 75% effficient

Million BTU/unit Available units per million BTU

Anthracite 26.27/ton 0 .0508

Bituminous
low/medium volatile 28.72/ton 0.0464
high volatile 24.72/ton 0.0539
sub bituminous 19.19/ton 0.0695
lignite 13.95/ton 0.0956
charcoal 25.00/ton 0.0533

____________________________________________________________________________________________

The sub bituminous coal from Wyoming burns cleaner but requires that
twice the amount of pulverized coal be burned to achieve the same heat
value IN STEAM service.

Cornell University and other steam plant operations
used met coal in their flat bed Riley coal stoker and the other brand of stoker
and they paid $86 per ton for this coal as of the year 2000.

Cornell no longer burns Met. coal and uses natural gas.
I hope they left the stokers in place as they will need them
someday soon.

With larger coal stokers both an induced draft and forced draft are
required to achieve maximum COMPLETE burn.

In Cornell's case the east hill neighborhood like many other
university towns neighborhoods with coal fired steam plants that did
not have bag houses for some pollution control were always
coated with fly ash.

___________________________________________________________________________________________

Having said that I an not sure if the compressed wood bricks "Bio Bricks) being one brand
would be an option for them as they burn cleanly with little smoke but require smaller firebox.

Having said that; and taking my case in example I have created a huge amount of thermal mass by
filling half my fire box with firebrick after placing a 12 by 12 by 2 inch piece of channel iron on the grate support frame of my Switzer CWW100 wood and coal boiler. this kep the boiler hot and the firebox hot and aids in combustion.

I stacked two bricks on top of each other and burned a package of Bio Bricks to try them and they
burned well. I probably could have burned more of them at once but I did not at that time last fall.
I probably could have burned all four bricks at once but I did not.

windyhill4.2 · Post by **windyhill4.2** » Sun. Mar. 01, 2015 11:51 am

How is it thought that one could buy sub-bit from Wyoming cheaper than to have anthracite trucked from Pa. to up-state N.Y. ? Why have eco-bricks been brought up ? Eco-bricks are for city folks to use for recreational burning,not to fill a wood eating monster.Why does the railcar load of coal always surface when that issue has already been researched to death as a totally non-feasible option for an individual to do ? None of those absurd suggestions gets the OP closer to freedom from the slave labor of feeding the wood monster.There is no point in arguing about oiled coal,filling the firebox with firebrick will not get the OP freedom from burning wood.Even the bit burning expert ,BERLIN, points to anthracite coal & equipment as the best solution. Anthracite ~~~ it is what is for heat,can we provide a solution for converting this OWB to coal or replace it with a coal boiler/s ? I would certainly question the sensibility of modifying the OWB with its age .... 12 yrs ? Is this unit a TRUE close-loop,pressurized boiler ? If not,it will leak b4 long so the best option in that case is to replace it.I would strongly suggest that the OP study the thread`` Pictures of your boilers `` as good food for thought on different possibilities,i found that thread very helpful in planning my own "From OWB to EFM520 installed in a truck box ". There is freedom from the slave labor of feeding a wood monster ~~~ the answer is burning anthracite in a coal stoker boiler.