where to buy a 300,000 BTU coal fired steam boiler stoker

I'm glad you all are happy with your boilers, but I don't really follow how they have "an edge in a steam application". An EFM 900 has a 4" outlet, will maintain pretty much any boiler temperature you like year-round and will make loads of steam when you need it. And I don't really follow how having an idle fire the size of a basketball is an advantage - it seems like you'd be burning a lot of fuel even when you have no call for heat. I've run steam systems in 2 houses with EFM's and have 0 complaints. Other boilers and stoker designs might work equally well, but unless they have real advantages I don't know about, I don't want to trade.

Mike

new softcoal stokers

http://www.willburt.com/cm/productCoalStokers.asp

or traders guide, internet, pennswoods, craigslist

Hard coal stokers

here on NEPA there are a few very good guys to purchase from

coaledsweat wrote: IIRC, that was why he decided he had to have an Axeman.

I hate to drive this thread farther off topic, but I think the height of the steam piping in Townsend's house favored the low water line of the Axeman...an EFM would have required digging a boiler pit. He also mentioned that having a common coal size for his stoker and hand fired stoves was a bonus. The design of the Axeman does promote a quick response, but in that particular installation I think the huge near-boiler piping and very well balanced venting of the system gets most of the credit.

Each installation is different, and there are design aspects of each boiler style that might be more desirable in one situation than other. One thing that doesn't change with boiler choice is how important the near-boiler piping is to the performance of the system.

If one stoker boiler won't do the job, two usually will.

pumpkinfarmer7 wrote:Where to but a 300,000 BTU coal fired steam boiler stoker? Thank you.

If it turns out you need more than 300k, there's always: Monster Keystoker K30

Mike

Seems like you experts went & did it again & scared the poor guy off. Come on pumpkinfarmer, where ya going with this? God knows these guys have given you a slew of info to try & help you out. A couple even answered your initial question.

w/ steam you should only fire the load , radaition fan coils ect., then add 15 to 20 % for piping & pick up, thats it nuff said andif you can afford it i would go w/ the efm

Oh yea, now that's a boiler.

Pacowy wrote:

pumpkinfarmer7 wrote:Where to but a 300,000 BTU coal fired steam boiler stoker? Thank you.

If it turns out you need more than 300k, there's always: Monster Keystoker K30

Mike

jim d wrote:w/ steam you should only fire the load , radaition fan coils ect., then add 15 to 20 % for piping & pick up, thats it nuff said andif you can afford it i would go w/ the efm

Agree 100% on the EFM's - done that 3x.

Disagree 100% on the sizing. In your scenario, anything that causes the coal boiler and the system as a whole to perform less than its idealized capacity will leave you with reduced steam output and largely unable to control where the steam goes. Marginal coal, boiler needs cleaning, DHW load, uninsulated distribution lines, jackets off, ash door gasket coming loose, etc. On top of that, the bigger boilers generally have bigger heat exchange areas so, all else equal, more of the heat goes into the water and less goes up the stack. There's a reason that old coal-fired steam systems have big boilers, and I don't believe it's because the Dead Men didn't know what they were doing. There have been people on the forum with steam systems who have had problems with coal boilers matched too closely to their measured load. I once had an underpowered steam system, and as you probably can tell, that's a pet peeve of mine. So I say listen to the Dead Men. "Those who cannot remember the past are condemned to repeat it."

Mike

Pacowy wrote:I don't really follow how having an idle fire the size of a basketball is an advantage - it seems like you'd be burning a lot of fuel even when you have no call for heat. I've run steam systems in 2 houses with EFM's and have 0 complaints. Other boilers and stoker designs might work equally well, but unless they have real advantages I don't know about, I don't want to trade.

Axemans don't burn at idle, they basically choke off the fire. No one suggested you trade, enjoy your EFM.

Thanks, I will. Someday I'll have to learn more about the Axemans. They seem to have withstood the test of time pretty well.

Mike

coaledsweat wrote:Axemans don't burn at idle, they basically choke off the fire.

This was bugging me at breakfast this morning. I think the earlier posts said the Axemans tend to maintain a high boiler water temp because the idle fire is the size of a basketball. If it's giving off enough heat to maintain high boiler water temps (relative to a stoker with a smaller idle fire), it seems like it has to be taking in air and burning fuel to do so?

Mike

mike why would youhave a boiler that isn't performing properly , fix it , it's more likely that the boiler mfgrs overrate their boilers ,that fomular for sizing steam boilers has served me well for 50 years

jim d wrote:mike why would youhave a boiler that isn't performing properly , fix it , it's more likely that the boiler mfgrs overrate their boilers ,that fomular for sizing steam boilers has served me well for 50 years

I think we're at least partly agreeing here. I see people measuring their installed radiation, adding a small pick-up factor and then deciding what boiler to buy based on the ratings on the manufacturer websites. I agree with you that many of those ratings are higher than the unit is actually likely to perform, and that's part of why I'd be more comfortable with specifying more excess capacity. I've seen all kind of weird stuff happen when stokers of different designs get pushed close to their maximum output. For example, I had a flat plate stoker that picked a deep cold spell to let me know my recent coal delivery was more prone to clinker formation - due to plowing, etc., I had to baby it when I needed it to really go. Likewise, even EFM's can come up short at the top end if your coal has too large of a % of undersized pieces, but you may not find that out until you need that output. Making steam by coal, I'm much more comfortable building in excess capacity to provide protection against such factors, not to mention the boiler needs cleaning/DHW needs/future expansion/etc. factors that might lead you want to keep some capacity in reserve. And I know I'm repeating myself, but I believe I'd get the same heat with less coal using a bigger boiler running at 2/3 of its capacity vs. a smaller boiler running flat out (at least if the bigger boiler has a bigger heat exchanger). If someone has more info on that theory I'd be happy to hear it.

Thanks.

Mike

P.S. The older EFM literature I've seen seems to call for pickup factors of 1.33-1.35.

Pacowy wrote:

jim d wrote:mike why would youhave a boiler that isn't performing properly , fix it , it's more likely that the boiler mfgrs overrate their boilers ,that fomular for sizing steam boilers has served me well for 50 years

I think we're at least partly agreeing here. I see people measuring their installed radiation, adding a small pick-up factor and then deciding what boiler to buy based on the ratings on the manufacturer websites. I agree with you that many of those ratings are higher than the unit is actually likely to perform, and that's part of why I'd be more comfortable with specifying more excess capacity. I've seen all kind of weird stuff happen when stokers of different designs get pushed close to their maximum output. For example, I had a flat plate stoker that picked a deep cold spell to let me know my recent coal delivery was more prone to clinker formation - due to plowing, etc., I had to baby it when I needed it to really go. Likewise, even EFM's can come up short at the top end if your coal has too large of a % of undersized pieces, but you may not find that out until you need that output. Making steam by coal, I'm much more comfortable building in excess capacity to provide protection against such factors, not to mention the boiler needs cleaning/DHW needs/future expansion/etc. factors that might lead you want to keep some capacity in reserve. And I know I'm repeating myself, but I believe I'd get the same heat with less coal using a bigger boiler running at 2/3 of its capacity vs. a smaller boiler running flat out (at least if the bigger boiler has a bigger heat exchanger). If someone has more info on that theory I'd be happy to hear it.

Thanks.

Mike

P.S. The older EFM literature I've seen seems to call for pickup factors of 1.33-1.35.

I don't dis-agree here. Read this article for a better explanation:

http://www.masterplumbers.com/plumbview ... boiler.asp


However, Make sure you still do a heat loss and check your existing radiator sizing. In retrofitting a boiler, you may want to see if building energy improvements allow you to remove any radiators. (or downsize). May not be pratical or economical but should be checked anyway.

A bigger boiler running at partial load of around 75-80% will be more efficient than a smaller boiler running at 100% simply due to the btu per square foot of heat transfer area. This permits more heat to be sucked out of the combustion process. However, too big is not better as any savings gained at near full load will be lost in standby losses at partial loads.

Interesting article, thanks. I think his point about the pickup load dropping out assumes that the distribution piping is properly insulated. In some older houses - e.g., where asbestos insulation has been removed - the undersized boiler would never catch up.

And I certainly agree that too much oversizing is counterproductive.

Mike