Yanche wrote:Last week I took my AHS S-130 Coal Gun stoker boiler back to the factory for some modifications and additions. I had removed the combustion blower and it was easy to see the crud buildup on the combustion gas path. Jeff, AHS's founder, suggested taking the boiler to a car wash. I did that and it worked well. I used the spray wand type and it cleaned the passages down to bare metal. It did a very good job. I would expect a pressure spray washer, something I don't own, would do an equally good job.
Yanche wrote:I agree the "self cleaning" claim is a bit overblown. But at least in my boiler the buildup had the characteristics of air stream flow. What I mean there were streaks where it was fairly clean right down to the metal. There were other places where it was not. So there is some validity to "partially self cleaning". For best heat transfer efficiency an annual cleaning by brushing, scraping or pressure washing would be advised. My first cleaning was after three seasons of use. What I saw this time after one season was not much different. Suggesting that at least in my installation where I have a short stove pipe path to a completely vertical clay lined chimney, i.e. good flow characteristics, the buildup seems to reach a certain amount and doesn't continue to grow.
What does concern me is the buildup of burnt coal pieces pushed directly into the entrance of the boiler tubes. This appears to be caused by too high a burning fire in the "stack" of coal. The coal height stack is set by the frequency of ash grate operation. My boiler has the standard timer option and I do not adjust the setting much. Perhaps it's an operational adjustment problem. I did have a thermocouple sensor installed so I will be switching to the "thermo-ash" style of control for this heating season. I'll report the improvements if any in a year.
I bought my AHS 130 boiler new 5+ years ago, before I discovered this forum and educated myself about installing and operating them. For reasons that not even Jeff at AHS can explain the supply taping on my boiler was on the front (inspection port end) of the boiler. The return tapping is on the lower front left of the boiler. All the AHS boiler photos I have seen show the supply tapping on the top rear of the boiler. It's my engineering belief the for good thermal heat transfer the water flow in a boiler should flow across the extremities of the boiler. I believe that placement of the supply tapping on the front of my boiler was a mistake made by AHS. Jeff tried to convince me that the location wouldn't make much difference. I wasn't convinced. So I put my money where my mouth was and paid them to move it.RICHARD2 wrote:Yanche wrote:Last week I took my AHS S-130 Coal Gun stoker boiler back to the factory for some modifications and additions.
I'm am curious to know what "modifications and additions" you are making. Would you mind elaborating?
Yanche wrote:for good thermal heat transfer the water flow in a boiler should flow across the extremities of the boiler.
Yanche wrote:Stay tuned, in a couple of months I'll post pictures and operational data.