Seanbabs· Pallin' around
Ahhh I see. So it is more of a lean flammability limit thing than a totally inert environment. Makes sense. I was thinking they were doing something like a 30 millitorr vacuum to create a totally inert environment, which would be extremely hard with water vapor and CO/CO2 off-gassing. (however, without combustion CO/CO2 off-gassing is << Water vapor)Inert atmosphere would work, but it's pointless when you can just suck the air out. Either way the carbon will outgas, and you want to get that shit out of the furnace. Ergo, according to Wiki (don't know who wrote that section, not cited), they pull a vacuum on the chamber. You're right that they won't be able to maintain a perfect vacuum, but they can start with a low pressure atmosphere and continue to draw out the moisture and gasses as they evolve. No fire will start.