Burning Sub-Biuminous C coal in a Anchor underfeed stoker.
In the winter the circulation pump rarely turns off and I'm making nice clinckers, pulling them twice a day and filling hopper with coal twice a day, could probalby streach to 24 hours but why.
The weather has warmed, spring is in the air, 38 F during the day and 10 F at night, circulation pump seams to be off all day, solar heat gain and 50% slab heat, tending boiler once a day.
Clinckers seam to grow vertically out of the ash, and don't seam to absorb the ash as well as in the winter, the problem is the ash is now filling my combustion chamber.
Is it time to adjust coal feed rate and air to get longer run times with hopes of hotter fires that melt the ash better.
I will start experimenting soon, summer is coming and I anticipate this problem will only get worse, I will be burning all summer as I now have an indirect hot water heater.
Monthly average low temperatures are only above freezing three months here, so keeping the boiler running thought the summer for the hot water is not a big deal.
My boiler controls turn the stoker on at about 160 off at about 180 when there is call for heat, and a low temperature cut out for the circulation pump at 140 to prevent condensation, this low temperature cut out also starts the stoker. I installed a relay to latch the stoker on, any time it starts, until the high temp cut out at 180 shuts it off, to lengthen run times.
This coal and stoker combination seams to hold fire well, it can be unplugged for at least twentyfour hours and still fire up, so no hold fire timer.
Question, Will adjusting my feed rate from maximum and adjusting the air get a longer burn times and hotter smaller fire that will clincker better and ash less?
I will be experimenting but thought some advice may be helpfull.
Oil is getting to 5$ a gallon here and people are starting to ask me questions, the three Outdoor hand fed Wood/Coal boilers in town have basically disapointed, in my opinion.