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A D V A N C E D M A T E R I A L S & P R O C E S S E S | J U N E 2 0 1 5
FEATURE
Fig. 13 —Plots of power consumption in furnaces with graphite
and all-metal hot zones heated to 2200°F and held for two hours
show that the graphite hot zone is about 30%more efficient.
with graphite, solvents, and diffusion pump oil. Graphite and
molybdenum hot zones can produce contamination-free
surfaces with proper techniques including clean work, low
leak rates, low initial pump down, and precycle bake-outs.
Molybdenum furnaces have inherently lower vacuum levels.
Graphite furnaces consume less power, require lower capital
investment, and have longer life. Graphite furnaces consume
30% less power than molybdenum, and those with molyb-
denum hot zones have a higher capital investment, shorter
life, and are more difficult to maintain.
This article is adapted from a presentation by Trevor
Jones at 2014 Furnaces North America.
For more information: Reàl Fradette is senior consultant,
Solar Atmospheres Inc., 1969 Clearview Rd., Souderton, PA
18964, , .