How do I calculate the amount of methanol I'll need for my carburizing atmosphere?
Carburizing and other carbon control atmospheres all require a source of
CO to facilitate the diffusion of carbon into the surface of the metal.
One source is through endothermic atmosphere generation, in which air
and natural gas are reacted in an external generator to form a gas
composed of 20% CO, 40% H₂, and 40% N₂, with trace amounts of CO₂ and moisture.
Another source of CO is the introduction of a blend of 40% nitrogen and
60% methanol into the furnace, which forms a gas of the same
composition produced endothermically. The heat of the furnace
dissociates the methanol (CH₃OH) into CO and H₂
which then blends with the nitrogen. Here's how to calculate the amount
of methanol needed. For 1000 scf of atmosphere, as an example, 40% or
400 scf will be nitrogen, according to the ratios above. The remaining
60% or 600 scf will be made up of dissociated methanol. Since one gallon
of methanol dissociates into approximately 240 scf of gas, 2.5 gallons
of methanol would be needed to dissociate into the required 600 scf of
atmosphere.
Read more...
