A challenge to anthracite stove makers

The highest CO2 ever achieved in an oil burner was accomplished in the burner that succeeded in doing the best job of mixing air with the oil before combustion instead of after as modern burners do. All blue flame.

We can't convert coal to a gas though it contains a certain amount of gas, but we can select a combustion chamber that has the best chance to mix air as evenly as possible. The shape of that chamber, I think should be round and it should be insulated all around. Lining it helps but better still would be to suspend it as is done in the Chubby and then line it. Another excellent approach is in the Vigilant stove where flue gas is circulated around the back of the chamber. That chamber back will remain very hot with almost no heat loss. A design could be made to do the same thing around a round fire pot which would almost totally insulate it. The job of a combustion chamber is to burn the fuel and it will do it best if it is hot. Any heat loss to the sides will compromise that job. This is one area where both antique and modern stoves fail. If you look at a dying fire the area that is still lit will be in the hottest part which is the center, the part with the least heat loss. The coal surrounding will be only half burnt having lost heat to the sides. Any attempt to consider the fire pot part of the heat exchange will result in a poorer performance. When we read of stove polish falling off a fire pot because it is too hot the reason is bad design. This was known and utilized in commercial boilers back in 1850 to the best of my knowledge, maybe earlier. Combustion must always be separate from heat exchange.

The problem is how to achieve the separate needs of combustion and heat exchange in a compact package which our parlor stoves need to be. So far the old base burners come closest if you bar electricity. Excellent modern examples of good heat exchange design are in the Surdiac and Franco Belge stoves. Their failing is in the long thin combustion chambers with too low a burning mass.

The next consideration is how to supply air both above and through the coal and do it in a uniform and timely manner. There are examples both old and new that do it very differently than what we are used to.

Then we come to the grate but this is getting too long and I don't know if there is any interest.

Franco B,

Well, there is interest here, but I just wrote a long post and the system logged me out before I cold post it so I lost everything. I'll try again another day as I'm off to bed...

dj

dlj wrote:Franco B,

Well, there is interest here, but I just wrote a long post and the system logged me out before I cold post it so I lost everything. I'll try again another day as I'm off to bed...

dj

Just use some other editor, like your word processor or even Notepad, to compose your message. Take your time use the spell check, etc. Then when your done, "Select All" and paste in into the reply window. That way if your forum connection times out you have lost you typing.

franco b wrote:

Then we come to the grate but this is getting too long and I don't know if there is any interest.

No please continue you have peaked my interst. I enjoyed reading your post



Eric

franco b wrote:The highest CO2 ever achieved in an oil burner was accomplished in the burner that succeeded in doing the best job of mixing air with the oil before combustion instead of after as modern burners do. All blue flame.

We can't convert coal to a gas though it contains a certain amount of gas, but we can select a combustion chamber that has the best chance to mix air as evenly as possible. The shape of that chamber, I think should be round and it should be insulated all around. Lining it helps but better still would be to suspend it as is done in the Chubby and then line it. Another excellent approach is in the Vigilant stove where flue gas is circulated around the back of the chamber. That chamber back will remain very hot with almost no heat loss. A design could be made to do the same thing around a round fire pot which would almost totally insulate it. The job of a combustion chamber is to burn the fuel and it will do it best if it is hot. Any heat loss to the sides will compromise that job. This is one area where both antique and modern stoves fail. If you look at a dying fire the area that is still lit will be in the hottest part which is the center, the part with the least heat loss. The coal surrounding will be only half burnt having lost heat to the sides. Any attempt to consider the fire pot part of the heat exchange will result in a poorer performance. When we read of stove polish falling off a fire pot because it is too hot the reason is bad design. This was known and utilized in commercial boilers back in 1850 to the best of my knowledge, maybe earlier. Combustion must always be separate from heat exchange.

The problem is how to achieve the separate needs of combustion and heat exchange in a compact package which our parlor stoves need to be. So far the old base burners come closest if you bar electricity. Excellent modern examples of good heat exchange design are in the Surdiac and Franco Belge stoves. Their failing is in the long thin combustion chambers with too low a burning mass.

The next consideration is how to supply air both above and through the coal and do it in a uniform and timely manner. There are examples both old and new that do it very differently than what we are used to.

Then we come to the grate but this is getting too long and I don't know if there is any interest.

The Base Burners designed for Anthracite only like the Andes I bought and like a Glenwood 111 have internally suspended fire pots like you are describing. The gasses are pulled down around the firepot from the top down around the sides and then down into the base heating baffles. So you have this space between the outer barrel and the firepot which is filled with hot gas as it pulls down. A Base Heater like the No 6 has the gas go outside and down the back rather than inside. So these base burner designs address the issue of a high heat environment for efficient combustion quite effectively.

If I was going to burn BITUMINOUS coal, this is the stove for it. Here is an article about a Globe Hot Blast. This is a superlative design for high combustion efficiency. So far I haven't found any Base Burner designs made for Bituminous coal. Francob hit upon the difficulty of making a properly insulated combustion area to provide a high heat environment to effectively burn hydrocarbons. A Warm Morning type stove is an example of this. the entire stove is highly insulated with bricks to make the fuel burn efficiently but the design really cuts down on Thermal efficiency because the thickness of the bricks prevent the heat from quickly radiating out into the room, therefore a lot of your efficienct combustion becomes stack loss because there is not enough time or space to allow the heat to radiate out of the stove.
But read about this brilliant design here. As far as an Oak type stove these might be one of the best here.

http://gingercreekstoves.wordpress.com/2011/02/13/new-globe-hot-blast/

Another fine example of Turn Of The Century applied intelligence.

When I modif. the Vigll, I wanted a very small combustion chamber so I placed 2 rows of fire bricks side by side, on the right and left sides and at the same level as the rear bricks. Then closed the front end witht the steel plate. No more air by-passing in the front bars and the heat is kept inside the coal bed.
Based on what William just said, I can think that insulated the fire "pot" at an extreme degree so the anthracite burns at a higher steady temp. Then the hot gasses are routed to the sides downward channels and after to the Z like path at the back of the stove. The heat is then extracted from the stove like a Base Burner. I was only thinking that the front plate was the thing that made the stove working so well but the fire bricks may also have made a good difference, I think?

I was supposed to switch to wood for the present warmer T. but wanted to see how the stove would react in these temps. This morning, I put 3 pounds (8Am) and tonight(8PM) 4 pounds. The stove idles at 250*F, same for about the last 2 weeks. This small heat is sent at 80% in the basement to heat the downstairs office. Better than playing with small wood fires.

wsherrick wrote:The Base Burners designed for Anthracite only like the Andes I bought and like a Glenwood 111 have internally suspended fire pots like you are describing. The gasses are pulled down around the firepot from the top down around the sides and then down into the base heating baffles. So you have this space between the outer barrel and the firepot which is filled with hot gas as it pulls down. A Base Heater like the No 6 has the gas go outside and down the back rather than inside. So these base burner designs address the issue of a high heat environment for efficient combustion quite effectively.

WE live and we learn. Would very much like to examine one of these stoves.

The fact remains though that most ignored this problem. The old stove companies had an advantage that modern manufacturers do not. They had sales in the hundreds of thousands which could finance a lot of R and D. And if you were not big enough you could always copy. A manufacturer today can't do that since the demand today is for a lower more compact stove suitable in many cases for installation in front of a fireplace. Even in its day the demand died out in favor of an almost totally different design.

wsherrick wrote:But read about this brilliant design here. As far as an Oak type stove these might be one of the best here.

I detect a lot of 19th century advertising bombast here. It does not claim to burn the smoke but only to burn it more completely. I was under the impression that your Glenwood also had a hot blast ring. I like the design but more for a bit of overfire air to burn volatiles and CO.

But I still think that a modern anthracite stove, outperforming all what exist now and well advertised would make a hit. Actually,I tell to a lot of peoples here all what I can make with anthracite but I say at the end of the discussion: don't think to buy an anthracite stove now: they are not ready... If a hand fired stove, performing like mine and certified was avalaible, it would get top sales. I meet a lot of peoples every days and a lot of wood burners are ready to go for a change. But first the stoves must change.
The Vigilant ll could be an almost ready candidate with just a few changes and at a low cost. Vigilant lll. I don't love the original one but I know that it could be a perfect starter for R & D.

On the old Glenwood #6, there are two sets of what I guess you can call heat deflectors. There is the large deflector just under the door going around the top of the fire box. Then there is another on the top of the stove. I always thought they were to help in air circulation for spreading the heat around, and I'm sure they do that. But perhaps the lower one going around the fire pot helps keep the heat in, aiding combustion.

It seems the person that started this thread, coalnewbie, got this discussion started by saying "In my book none of the above stoves are worth a damn as modern anthracite burners (with apologies to Mr. Herrick)" with the base burners part of the above...

I think we can safely say that the Glenwood baseheaters are (when they are in good condition), in fact, extremely good as modern anthracite burners. How good? Well that seems to be up in the air a bit with two sides on that one. We don't have hard numbers on the Glenwood. How many BTU's do they produce? What is the actual combustion efficiency? What is the thermal transfer efficiency? (this last one of course, nobody knows for any of the stoves produced, old or new).

There's one thing about the baseburner that is hard to define. With no blowers, it circulates the heat in the space it's heating like no other stove I've ever owned, including modern stoves. However it does it, the design of that stove causes an air circulation that is excellent.

It's easy to run, so are many modern stoves. It runs over a large range of temperatures allowing for use over most of the heating season, so do many modern stoves. It seems to consume little coal for the heat it produces. Well, it seems there are a couple modern stoves that sound like they are on a par with that. This last point is kind of a sticky wicket, so to speak. Everybody likes to think their stove does well on this (well most everybody). My position on that point, everybody's right! If you're burning anthracite (and possibly bituminous) you are doing a whole lot better than most...

If someone is interested in designing a modern stove are there design aspects that could be taken from the Baseburners? I think so, but what are they exactly? How do you design a modern stove that incorporates good combustion design, good thermal transfer design and good to look at? That's a tough nut...

dj

dlj wrote:I think we can safely say that the Glenwood baseheaters are (when they are in good condition), in fact, extremely good as modern anthracite burners. How good? Well that seems to be up in the air a bit with two sides on that one. We don't have hard numbers on the Glenwood. How many BTU's do they produce? What is the actual combustion efficiency? What is the thermal transfer efficiency? (this last one of course, nobody knows for any of the stoves produced, old or new).

Really excellent post.

Overall efficiency takes into account both. It is known for some stoves from official lab. numbers. What is not known is the firing rates at which those efficiencies were obtained.

Concerning air circulation. A radiant stove will fill a room with infra red radiation at the speed of light. that infra red warms every thing it impinges against warming it and in turn re radiating. Air temperature is only something we infer comfort by. We are comfortable when our bodies heat loss is balanced by heat gain. We see people in ski resorts at below freezing temperatures in swimming pools. The wind is blocked and they absorb heat from the strong sunlight at high altitudes. For this reason I take with a grain of salt the claim that radiant stoves do not distribute heat as well as those designed to distribute air. The increased velocity though of the air going through the restricted passages of a convective stove might increase the efficiency of heat transfer.

I think that if my VC is 500*F on the top griddle and at 125*F at 17" H from the stove top, it's an efficiant stove. No baro, no manual damper, never had a back puffing. Just the internal damper to do what a heating stove has to do. The Vigll is rated in the owners manual at 50,000 Btu/hrs, max.area heated 2,000 sq.ft.
With about 1/2 the size of the original fire chamber, I heat 2,200 sq.ft.(same T* on the 3 levels) and with less anthracite. We must be awared about numbers, sometime numbers, testing and all statements don't apply. I'm not sure if sotves makers have a stove they make in their's own houses to see and study what they produce...

Why look for a complicated solution? Plus the Vigll has the best ashes handler system: swing out ash pan with a sliding on lid. " Base burning" (2 sides and back side) long path for the gasses. Just a few modifs on the original model and this stove can be a super stove. But I said it: with some mofifs. but easier than starting from 0.
And these stoves can easily be enameled for a colored look and be easier to match all decos in old and new homes.
P/S I don't sell stoves but I love them

franco b wrote:

wsherrick wrote:But read about this brilliant design here. As far as an Oak type stove these might be one of the best here.

I detect a lot of 19th century advertising bombast here. It does not claim to burn the smoke but only to burn it more completely. I was under the impression that your Glenwood also had a hot blast ring. I like the design but more for a bit of overfire air to burn volatiles and CO.

Yes the Glenwood has the overfire hot blast ring. What is think is neat about the Globe Stove here is that the firepot has a thermos like air chamber all around it to pre heat the secondary air before it goes over the top of the firepot.

wsherrick wrote:If I was going to burn BITUMINOUS coal, this is the stove for it. Here is an article about a Globe Hot Blast. This is a superlative design for high combustion efficiency. So far I haven't found any Base Burner designs made for Bituminous coal. Francob hit upon the difficulty of making a properly insulated combustion area to provide a high heat environment to effectively burn hydrocarbons. A Warm Morning type stove is an example of this. the entire stove is highly insulated with bricks to make the fuel burn efficiently but the design really cuts down on Thermal efficiency because the thickness of the bricks prevent the heat from quickly radiating out into the room, therefore a lot of your efficienct combustion becomes stack loss because there is not enough time or space to allow the heat to radiate out of the stove.
But read about this brilliant design here. As far as an Oak type stove these might be one of the best here.

http://gingercreekstoves.wordpress.com/2011/02/13/new-globe-hot-blast/

Another fine example of Turn Of The Century applied intelligence.

Very nice stove. Gingercreekstoves has a lot of beautiful antique stoves and is a very nice person to talk about stoves.
nortcan