More Details on the Black Bear Boiler

[Eric Johnson]

According to a nice article in the Maine Sunday Telegram, the Black Bear boiler company is ramping up for production. Apparently, it's a very clean burning, efficient outdoor/indoor boiler that retails for about $7,500.

Here's how the paper described the technology:

"The Black Bear Boiler uses a blower to ignite wood gasses. They burn at very high temperatures, passing over a heat exchanger to warm water and feed baseboards in the house. the firebox is surrounded by a massive ceramic refractory that also slowly absorbs heat. Turning off the blower removes oxygen from the unit, and the fire instantly goes out. but the refractory remains extremely hot for up to 48 hours, and the fire will reignite when the blower flips on again."

Instead of having a 20- or 30-gallon water jacket, like a conventional boiler, this thing apparently uses a heat exchanger with much less water capacity.

It looks to me like a modified Garn, but much cheaper and easier to use, if the publicity is to be believed.

I think I'll head up to East Millinocket early next year and check it out for myself. Get 'em to toss a load of wood in the firebox and see what comes out the stack.

 

[wg_bent]

A full report when you return Please

 

[Eric Johnson]

They're calling it a "downdraft gasifier" which is not new technology, and not really new tech for a small wood boiler, since I think Garn makes something quite similar. The best I can gather from the website is that it has 6.5 gallons of water capacity at the boiler. I tried to join up and ask some questions at the forum, but it doesn't appear to be working at the moment. They've got the other OWB boiler guys like Central Boiler all cheesed off because part of their sales pitch is that their technology is so much cleaner and more efficient.

I have nothing against OWBs in principle, but I have noticed that the people who own and sell them are really sensitive to criticism. They won't tell you, for example, how much wood they burn in a season. "I don't count every stick" is how one CB owner responded to my innocent question. And with all the negative publicity, they're getting touchier all the time. Hey, I would be too if I had that kind of investment at risk of being banned.

 

[laynes69]

Not exactly sure which company I was reading about, But they closed their line of OWB'S and were coming out with a downdraft gassifier. Now if im right here, they would have a longer life span due to less water for less leaks. The only thing I would see would be some expensive parts, or the high heat causing premature failure. If technology heads in this direction, which I think it is, It would be a nice thing to choose from. Some of the refactories can hold temps of 2200 degrees. You take this and put into a heat transfer system, you'll have a very clean, efficient burn. I could see other companies getting pi$$ed off by this. If they are 7500 thats sounds fair. Just one thing the people who like to burn green fresh cut wood would have to have seasoned wood for one of these. I'd be inserested in buying something like this if the technology proves to perform. Its already in indoor woodboilers, why not put it outdoor. Very interesting. It be like a black and white tv compared to a hdtv. Is this it??

(broken link removed)

 

[Burn-1]

These look a lot like the Seton Boiler from Montana, and I spoke with Fred Seton the owner last year and I think I remember him saying his boilers were made in Maine. His is an updraft design with a refractory core. He also sells a refractory wood stove which is sort of like a portable masonry heater but not as pretty as most wood stoves. Seton Boiler

I looked at a lot of these, TARM, GARN, AHS Woodgun, Greenwood Technologies and Eko,(New Horizon Corp is U.S. importer). I am really thinking about getting an Eko in the next two years or so. It has all the technology and is more affordable.

 

[webbie]

Here is what I learned about boilers when I worked with Tarm. An important feature is sq ft of heating surface - exposed to water! The Black Bear looks like decent combustion, but a Tarm has this and also water around 100% of the firebox and also a number of firetubes up through the rear heat exchanger. Before you buy any boiler, calculate the number of square inches of surface area exposed to the fire.

 

[begreen]

These look a lot like the Seton Boiler from Montana, and I spoke with Fred Seton the owner last year and I think I remember him saying his boilers were made in Maine. His is an updraft design with a refractory core. He also sells a refractory wood stove which is sort of like a portable masonry heater but not as pretty as most wood stoves. Seton Boiler

I looked at a lot of these, TARM, GARN, AHS Woodgun, Greenwood Technologies and Eko,(New Horizon Corp is U.S. importer). I am really thinking about getting an Eko in the next two years or so. It has all the technology and is more affordable.

What kind of prices are you getting on the Eko?

 

[Eric Johnson]

The Black Bear supposedly comes with a 20-year warranty. Of course, that's only good if the company stays in business that long and never goes into bankruptcy.

Craig's point is a good one; I'm mystified as to how you get enough heat transfer through that heat exchanger to keep up with what the boiler is kicking out. One thing I do know is that instead of using water for heat storage, the BB uses ceramic, so it's pretty heavy. You would have to factor higher shipping costs into the equation. There's a regular on another plumbing & heating website who owns an Eko. I'll dig up the link and post it later, if anyone is interested in getting some first-hand information.

 

[webbie]

In my opinion, the lack of heating surface is usually cutting corners on the manufacturing end - it is extremely difficult creating 5 sided (and more) water-backed boxes. In addition, many shops sub out their heat exchanger work, so they often get something that can be inserted into the boiler body as opposed to the boiler body itself. There are no shortcuts in making a wet-backed and wet-leg boiler - lots of cutting and lots of welding...and lots of high grade steel.

 

[begreen]

Greenwood claims the large mass of ceramic refractory brick to is temper the up and down swings of wood burning. This allows them to throttle the fire according to load as opposed to a continuous smolder. They use a large coiled tube exchanger over the back and top of the boiler. One advantage of this over the jacket boilers is servicability. The other is less cooling of the fire due to direct contact of the jacket with the fire and less thermal stress on the steel. All designed towards cleaner burning. It looks like Eko might also use a variation on this theme.

 

[Eric Johnson]

Here's the link to the site where one or members owns an Eko:

http://forums.invision.net/index.cfm?CFApp=2l.

Most of these guys are plumbing & heating professionals.

 

[Eric Johnson]

Does it matter, Craig, that this is a gassifier? Couldn't you use the same kind of heat exchanger technology (i.e., water tube or cast iron) as you'd find in a conventional gas or oil boiler? Or would the wood gassifier still produce too much soot and other crap to make that impractical? I was thinking about buying a chip gassifier many years ago and the manufacturer suggested mating the gassifer up with a conventional gas boiler, using wood gas instead of nat. gas or propane.

In my opinion, the lack of heating surface is usually cutting corners on the manufacturing end - it is extremely difficult creating 5 sided (and more) water-backed boxes. In addition, many shops sub out their heat exchanger work, so they often get something that can be inserted into the boiler body as opposed to the boiler body itself. There are no shortcuts in making a wet-backed and wet-leg boiler - lots of cutting and lots of welding...and lots of high grade steel.

 

[lyndske]

In my opinion the key to a clean burn is high combustion tempuratures which gasification boilers get from a ceramic lined chamber. If the fire box has a water jacket around it the combustion tempurature is too low to burn the gasses making creosote and smoke.

 

[Reggie Dunlap]

I heard that the company making the Black Bear Boiler went out of business. Not sure how accurate that info is. I was interested in one myself, but ended up buying a Tarm.

Reggie

 

[MaineWoods]

I heard that the company making the Black Bear Boiler went out of business. Reggie

Ditto

Cliff
Eastern Maine

 

[Eric Johnson]

We have one user, Maine, who's got one. So they may be out of business, but their legacy lives on in the Boiler Room. I was always interested in the Black Bear, before I'd even heard of Seton or Greenwood. Seems like a technology with promise, but I don't think BB had the right product line nor the right marketing approach to get the job done.

I feel bad for Millinocket. They really need some decent manufacturing to replace Great Northern Paper.

 

[sparke]

Another Seton spin off. Also located in Maine. (broken link removed)

 

[deerhuntrer]

Eric,
Blame our wonderful warm friendly business climate, its called Baldacci.

 

[mikeyny]

As far as a water jacket around the fire goes, it definitly keeps the firebox cool. I have an older tarm under burn boiler and I get a bit of creosote on the inside of the boiler walls if I burn not so seasoned wood, but the only time I get any smoke up the chimney is on start up and that is mostly steam. This old tarm seems to burn all of the gasses before they go up the chimny as long as it is burning good and hot. It sounds like a freight train running by when it is at full burn. I have working on designing a wood boiler that has a firebox separate from the heat exchanger in order to get a good hot firebox, but high temps is a problem. I will need to line it with lots of good refractory.

 

[Eric Johnson]

Mikey, you should check out nofossil's brother's built-your-own gasifier project. They knocked off nofossil's EKO 25. Pretty cool.

https://www.hearth.com/talk/threads/11492/