By: Berlin On: Tue Jan 05, 2010 2:41 pm
the coal on the right looks like a much more uniform product. The best processors, usually with the fewest ash/debris in their coal will have nice uniform pieces like what's on the right, at least when dealing w/ bituminous. Small/more uniform pieces do require more air, not just because the particular coal may be more dense, but also because, as was mentioned, the uniform pieces require more air/pressure to burn throughouly. however the consistancy of the product should produce a very predictable and constant feed rate/ corresponding air setting.