As for running the combustion air full time, corn burns VERY HOT!! In the corn burners we make at Woodmaster, the 1 inch rod that the augers are made of glows YELLOW. So do the 1 inch tall (making a 3 inch diameter auger) by half inch thick "swirleys". And that's when they're set to only run at 100,000BTU. The 1100 model can go FAR in excess of 300,000, but the augers would need replacing every year, so the timers are limited to 150,000BTU output. According to the R&D guys, the hardest part about designing the corn burner was making the augers big enough to not melt, but small enough to not just grind the corn into powder.
Clinkers cannot be helped in a corn stove. It's a fact of life with them. It's like using pallets in a wood burning stove, you just have to deal with removing nails once in a while. In a corn burner, you just have to shut everything down once in a while and remove the clinkers.
The corn burners at Woodmaster aren't the most efficient at getting ALL of the energy out of the corn, but you don't have to worry about clinkers in them. There's an auger that removes the ashes (and clinkers) at the same time that the feed auger puts in fresh fuel (corn). But because of this, there's quite often a bit of unburned corn goes out the ash auger as well. For the sake of not having to deal with clinkers, you end up burning a little more corn.....
Hope this helps, and if there's any more questions, I'll be happy to answer (or ask the R&D guys at work and pass on the info).
