AHS S130 Coalgun- Puffbacks & Explosions

dchartt wrote: My draft on a normal day is around .01, .02 if im lucky,.....lots of condensation inside my hopper because boiler is in barn.

The condensation is due to the poor draft...and more noticeable due to the colder location.
If draft is corrected the condensation would go away.

watkinsdr wrote:BTW: Have you S130 folks complained to AHS about your unburned coal problem yet?

I mentioned it to them, and the hope is that things will improve with the coming of the colder weather. Time will tell.

Did your S130 get any better in this regard when the consistent cold weather finally arrived last year?

Hey Larry:

I installed my S130 the first weekend in April last spring; so, she never really saw really cold weather and consistent hard burning. I always had significant unburned coal in the S130's ash pan and never resolved the problem. The S260 however burns the crap out of coal. I've never had unburned coal in the S260's ashpan; even under light load, go figure... And that's the reason why I originally went with the S130; versus, the S260! I thought the S260 would have unburned coal in the ashpan under light load!!

Now that I've lowered the dump temp to 110 the boiler seams happier and there have been no booms. I need to watch the boiler but I see an inprovement. I'll let you know how things progress, One day at a time.

has anyone ever thought the whole "cyclone funnel" could be a problem? why did ahs choke the flue pipe down so much with the funnel?

dchartt wrote:has anyone ever thought the whole "cyclone funnel" could be a problem? why did ahs choke the flue pipe down so much with the funnel?

The funnel isn't part of the exhaust path, it's where the flyash is rejected to.

Here's a pix. Your flue pipe is connected to a 5" tube that goes inside and several inches below the port opening in the sidewall.

Pa papa wrote:Here's a pix. Your flue pipe is connected to a 5" tube that goes inside and several inches below the port opening in the sidewall.

What I find with my AHS cyclone is the bottom of the cyclone clogs frequently. It appears the exit hole is to close the the ash grate and bottom ash that is sitting on the grate prevents the cyclone fly ash from falling. I use a long piece of flexible stainless rod to periodically ream it out. The rod is a old CB antenna, which I insert through and access hole drilled into my stovepipe. When I do ream it, I will see a trail of the darker fly ash in my ash bin after a couple of grate cycles.

I'm continuing to think of ways to solve he puff back problem. I believe the consensus is that it occurs on combustion fan shut down. I'm not currently having problems but have in the past. I do find fly ash on the lower arc of the inspection door pipe, i.e. the bottom edge of what the flapper door seals against. This means there had to be a reversal of air flow to put it there. Some air, or the suction effect of the opening swinging inspection port door put it there. Or perhaps a very slight puff back, blowing fly ash out the inspection port.

There was a suggestion that a variable speed blower motor could be programmed to slowly transition to off. This would in theory continuously pull the combustion mix through the boiler tubes, even after the flapper door opened. Perhaps the existing motor could be used as a two speed motor. Suppose upon shutdown the dual voltage motor windings were put it series, just like you would if you were to wire it for 220 VAC, but instead powered it with 110 VAC. It would run much slower, but it likely would still run, especially since it had just been up to speed. Now hopefully the flapper door would slowly open and the lower induced draft would continue exhausting the combustion gases. Then after some time power would be completely turned off. Time delays could be controlled by an electric furnace control sequencer. What do you think?

Yanche wrote: What do you think?

Sounds like it could work, maybe?

Finding the threshold point that the flapper door would release open is the biggest "unknown".
May be a hard mark to hit by the mentioned approach...only way to find out is to give it try.

Could coal that has been mildly oiled to reduce dusting have any relevance to puff-backs?

Oil is NOT an issue on the coal. Ashing, draft, level of new coal in the burn chamber. The observation door is to be left floating, not tightened to any particular tolerance. This is NOT an air tight device. Keep flogging the poor horse, though......

sure would be NICE if AHS actually had two cents in all of this and backed their product up and maybe came up with some sort of recall and a way to fix

I carried this relevant quote over from a different thread:

Beeman wrote:Final Report on this mini-puffback issue. I think my coal dealer Vern identified the source of the problem when he and I had a lengthy chat this summer while he was delivering 4 tons of Superior nut. This is the same coal size and source as last winter when I had the puffing issue. His commented that he thought the problem was from too much oil (about 1.5 gallons/ton) and said he heard from other customers with similar complaints. I concluded last summer that I would wait to see how the new coal burned now that he said he was adding only 1 gallon or less of oil/ton.

I am happy to report absolutely no puffing from this year's coal. I am forced to conclude--happily--that Vern was correct. Anyone else who ever has this mini-puffback problem should move possibly too much oil on the coal to the top of the list of probable causes.

Wishing everyone safe and steady burns!

dchartt wrote:sure would be NICE if AHS actually had two cents in all of this and backed their product up and maybe came up with some sort of recall and a way to fix

They can't fix what their customer does with their product. Puffbacks are not an AHS exclusive, any coal appliance can have them when operated out of their sweet spot, there are more than enough threads in this forum to prove that.