Opinions Sought on Condition of Cat Element

[Eric Johnson]

I've got an 8" add-on catalytic combustor that I bought a few years ago from Woodmanpartsplus in New Hampshire.

(broken link removed)

I used it for one season in my old boiler, but never had a great deal of success. I think boilers are not suited to catalytic technology, as none that I am aware of use this technology.

Anyway, I would like to sell it, but don't feel comfortable doing so without some independent help in determining its condition. Here's a few pics of the element (from both sides) and the assembled unit. Note that the black pipe section holding the round element is original and new--I used another piece of stove pipe in my installation. As to the element, there are no cracks, chips or other mechanical or surface damage. Looks pretty much like it did when it was new.

Given the information given above, is this something I should feel comfortable selling?

 

[Eric Johnson]

The assembled unit.

 

[begreen]

It looks in good condition. Should work ok in the right setup.

Did it get hot enough to fire off in the exhaust from the boiler? What were the average flue temps?

 

[Eric Johnson]

The flue temps would get up to 600, at which point I'd engage it and get temps above the element around 2,000, as I recall. I got no creosote in the chimney, but not much reduction in smoke, either, which is what I was really looking for. I notice that the Woodmanpartsplus website specifies these for "stoves and furnaces." If they worked in boilers, you'd think they'd make a big deal about it, all things considered.

 

[begreen]

Yes, you would think so. That actually sounds pretty good, but often retrofitted products don't work as well as built-in, by design solutions. Do you think the smoke was from gases that made it past the sides of the combustor?

 

[Eric Johnson]

I think it's a combination of the boiler producing more smoke than the cat could handle, coupled with what you said about retrofits not working as well as systems engineered into the appliance.

I've read comments from people who say these things work very well. It just didn't do what I was hoping for.

 

[Highbeam]

Reburning the smoke in the flue wouldn't help the boiler or furnace at all would it? I mean, you're already past the heat exchangers.

Hard to imagine 2000 degree flue temps without that single wall pipe glowing red.

 

[Eric Johnson]

Those were internal temps in the pipe. In theory, any unburned wood gas (smoke) should burn as it passes through the glowing cat element, I think. In a conventional wood-fired boiler or furnace, the "heat exchanger" is actually the firebox.

 

[Backwoods Savage]

Eric, I can see nothing wrong with the cat. You should be comfortable selling it. Now you just have to settle on a price.

btw, how is that barn full of wood holding out for you? How much did you go through last year?

 

[Eric Johnson]

Thanks.

The barn is holding out fine. My wood pile is about 10 feet away, so restocking hasn't been a problem. I like to keep it full of wood.

This winter, which has been a lot colder, looks like it will use about 22% less wood than last winter. I think there's probably another 10-20% waiting to be liberated.

 

[Backwoods Savage]

Sounds good Eric. But I highly doubt I can catch up with you on the wood supply. Maybe in my younger days...