I have used my econoburn 200 for the past two years to heat a 5000 sq. foot house, and two garages of almost the same sq. footage. The problem is lacking a pressurized hot water storage, it needs to be stoked every 3 hours and unless you are using VERY dry wood contra the manufacturers claims of 20% wet wood, it will never reach a temperature above 180F. Resolute to abandon my indentured servant status to the boiler, I tried to burn anthracite as a test run in the boiler. Once to temp, it glowed redder than Rudolph's nose and the gassing burning into the lower refractory was impressive. That being said, the slit to the lower refractory eventually was plugged. Here is the problem: It does not have an ash pan (just a lower refractory to remove any ash) and it lacks a grate in the upper box. After a 15 hour run, the water temp in the box began to cool as did the coal fire even with periodic stoking with nut coal (3 bags total). I believe it has to do with the ash in the bottom of the box that never really gets blown into the lower refractory as the mfg. says and builds up quickly ( much more quickly than wood). I had some amish blacksmith friends make me a 1/2" carbon steel plate with holes and a slit in the center with a sliding tower of same material to shake back and forth and to avoid any obstruction in the gasification process. It works well on continuing airflow but I do not see the gasification burning as before with the new rig, and it still does not move all of the ash to the lower refractory for an easier clean out. I am a newbie to coal so I have a few questions that I would be appreciative if you could help me answer:
1. Is there a better technique to burning coal in a downdraft gasification boiler with / without the shaker rig?
2. Is the turn in the temp due to buildup of ash, or could it be the amount of air supplied via the fan and should it be dampered moreso, or ?
3. Should I be burning stove coal instead of nut coal?
4. Any sage advice and wisdom!!!!
The tech guy said several owners of the econoburn near Pittsburg were burning coal and loving it but did not elaborate since it was built for wood (but can handle coal due to its carbon steel construction). I am almost there, but can't get it ongoing!