Coalgun- Puff backs & Explosions

Yanche wrote:The boiler also came from the factory with a switch to turn off the grate motor. I assume it's for turning it off while you remove the ash bucket.

The switch to turn off the grate motor is recommended in the AHS manual for use during start up.

I plan to purchase a second ash pan, so I will never have to shut off the grate switch while taking out and disposing of my ashes. After a quick swap of the ash pans, I can then take my good old time disposing of the ashes in the full pan.

Good idea. I don't know why anyone would own a stoker boiler with only one ash pan...I have 8. Saturday is "ash day".

A little off subject; but, since I started this thread, I give myself license to go off thread...

The "standard" AHS ash pan weighs 16 lbs empty... If 'yer lazy like me, you sometimes wait 3-4 days between dumping the ash pan---this translates into a "pain in the ash..." I had some extra Rubbermaid "table bus tubs" which my wife bought a few years ago, NOTE: They still have these tubs at Sam's Club, 2 ea. for approx. $14.00. I've been using them for about two weeks now; and, they seem to work pretty well. The plastic stays cool; and, I haven't noticed any burn marks yet... NOTE: I have my S260 elevated on 6" concrete blocks; which, seems to be just enough height to allow using these plasic tubs---any closer; and, the plastic will get too hot---don't ask me how I know... I only have 3 of these tubs now; but, if they continue to work, I plan on buying more...

Yanche wrote:My puff backs ended when I had my boiler factory modified to the tombstone style inspection port cover and flapper with rotatable opening. My theory is idle draft improved when the air heated by the front of the boiler rises and enters the open flapper. This improved draft reduces the concentration of out gassing coal gases.

Yanche,

Who did your modification and why did you do it?

rychw wrote:

Yanche wrote:My puff backs ended when I had my boiler factory modified to the tombstone style inspection port cover and flapper with rotatable opening. My theory is idle draft improved when the air heated by the front of the boiler rises and enters the open flapper. This improved draft reduces the concentration of out gassing coal gases.

Yanche,

Who did your modification and why did you do it?

The mods to my boiler were done by AHS at their original factory location, Harrisonville, PA. It was returned to have an additional supply tapping added. My boiler came with only a single supply and return taping. Both were in the front of the boiler. I believe it better to pipe a boiler so you have internal water flow across the entire water volume. To do that I needed a second tapping. I scheduled the mods with Jeff. I arrived at their factory close to their starting time with my boiler on a pallet. They removed it with a fork life, did the mods and had me on my way home shortly after noon. Service was excellent and the price was reasonable. I had the tombstone style inspection port and thermocouple installed at the same time. Theromcouple only, no associated controls. That's still on my to do list.

Yanche wrote:I had the tombstone style inspection port and thermocouple installed at the same time.

Yanche,

I agree that the craftsmanship and quality of work on the AHS boiler is outstanding. It is a great boiler when it works safely. Why did you have thew tombstone style inspection port installed? I wonder why AHS now has that type of inspection port on all their new boilers. Is there anyone out there with a new AHS boiler and the new inspection port experiencing booms?

rychw wrote:I agree that the craftsmanship and quality of work on the AHS boiler is outstanding. It is a great boiler when it works safely. Why did you have the tombstone style inspection port installed? I wonder why AHS now has that type of inspection port on all their new boilers. Is there anyone out there with a new AHS boiler and the new inspection port experiencing booms?

No booms here (so far). Closing in on one month of burning. Mine is an October 2009 model, so it is two years old, but it is seeing its first use. It came with the tombstone cover.

As for ash pans, sometime after mine was made they apparently lowered the profile of the AHS boilers yet again, and now their ash pans are completely different. Mine still uses an ash pan that is probably the same as for the Axeman's. The new AHS ash pans are much lower in profile to fit the new lower bottom end. My ash pan is 11.25" high, and my ash door opening is about 12" in height. I think the new AHS boilers ash pan door opening is only about 10" tall.

On my late model S260, the ash door opening is 10.25" tall; and, my AHS ash pans (which I'm not using because they're so heavy...) are 9.5" tall. The Rubbermaid Heavy Duty Bus Boxes are working great so far. I'm seriously thinking about using my AHS ash pans for the cat's litter box...

rychw wrote: Is there anyone out there with a new AHS boiler and the new inspection port experiencing booms?

I purchased my AHS-130 in 2007 and it has the tombstone cover. I had continuing problems with puff-backs over the first four seasons--destroying more than one barometric damper and even blowing the tombstone cover off on one occasion. So in my experience with the tombstone cover is that it alone is not a solution to the puff back problem.

This season, and I have been burning for 3+ weeks, I have yet to have a puff-back. Two things are different. First, while I purchased my coal from the same delivery agent and it came from the same breaker (Superior) the coal is different--this year it is white ash and in prior years it was red ash. Second I am operating at a lower SV--120. I never started out the season at 120 in the past. I have also noticed that I am getting more complete combustion of the coal with the SV at 120--there is no unburned coal visible.

my ahs130 is two weeks old, i experienced 3 puffbacks when i first fired her up and put a couple shovels of coal down in the hopper and closed the lid, that was pretty much my own fault though, other than that i havent had any problems with puffbacks

The deep mined red ash Superior brand coal was definitely more likely to have puff backs. I had several over the three seasons I burned it. A couple were quite spectacular, blown baro across room, bent inspection port door, etc. I even saw one from outside. Loud boom, and a quick look at my chimney to see a cloud of fly ash exiting. Only thing better would have been a smoke ring. Now with white ash coal and the tombstone style of inspection port, no problems.

Looking at the pictures of the exhaust pipe it doesn't look like you have any pitch. Just a thought.

I stand corrected, I went up to the barn this morning to check on the boiler and found the baro door blown off the pipe and laying on the ground in front of the furnace