slb04786 wrote:I am burning Blashack rice coal in my 520. I just started about 10 days ago. Seems to be working OK at the factory settings. I started out with 4/4 settings and recently set them at 3/3.5. Seems to be working OK at those settings. No outfires, feed tube is warm from the outside down about 4". I would think the bigger the coal (buck) would require a lower air setting as the bigger coal would allow more air through. Just my thinking. It isn't always right, according to my wife.
Buck is bigger it will need more air to burn all the way . If you set the air like you do with rice you will get alot more unburnt coal .buck needs more time & more air to burn all the way threw .That's why you slow the feed rate down and run more air. In a hand fed stove you would be correct bigger coal more air can passes threw smaller coal less air passes threw it. But the Air surface area on a hand fed grate is much larger Then a stoker. A stoker has 1/8 " or 1/16 size Air
holes. You need more air going threw them to burn bigger size coal and more time. Big size coal in a hand fed will give
you more heat but will burn up Quicker. The smaller size will give less heat but will burn longer. A Hand fed is Natural air
with bigger air ways threw the grates. Plus the coal sits there for hours or days .with a stoker stove the coal as less time to sit before it will pushed off with new coal feeding in. So you have less time to burn it up so you need more air and slow the feed rate down A stoker is force air going threw the coal with much smaller air holes