Replacing our hot zone in a 36 x 24 x 24 inch furnace. The insulation is fiber. The furnace does high speed steel at 2175 F. What would be a typical burn in cycle?
"When operating vacuum furnaces, situations may arise in which the hot zone and/or cold walls may become contaminated (Fig. Nos. 1 – 2). This can occur from a variety of sources: air leaks, outgassing from residues left on the parts as a result of the manufacturing or cleaning processes, vaporizatioRead more
“When operating vacuum furnaces, situations may arise in which the hot zone and/or cold walls may become contaminated (Fig. Nos. 1 – 2). This can occur from a variety of sources: air leaks, outgassing from residues left on the parts as a result of the manufacturing or cleaning processes, vaporization of sensitive materials (e.g., chromium-bearing materials), process-induced contaminations such as carbon in the form of soot or tar, fluxes from brazing pastes, excess braze alloy as well as many other sources. Often times the work being processed is also affected (Fig. 3). The question becomes, how do we attempt to clean up our contaminated vacuum furnaces? >>>Read More
Source: VAC AERO International
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Furnace burn out (a.k.a. thermal cleaning) cycles are important part of vacuum furnace maintenance. It is meant to reduce and outgas contaminants inside the heating zone and within the insulation. For new hot zone it is more related to drying, conditioning and outgassing the remaining resin from insRead more
Furnace burn out (a.k.a. thermal cleaning) cycles are important part of vacuum furnace maintenance. It is meant to reduce and outgas contaminants inside the heating zone and within the insulation.
For new hot zone it is more related to drying, conditioning and outgassing the remaining resin from insulation manufacturing processes. Every new furnace should be burned out at it’s nominal temperature and I’d say this rule should also apply to any hot zone replacement. Your hot zone supplier should be able to tell you the nominal temperature of the hot zone.
Duration of burnout should be at least 2 hours at the temperature, however you may keep it longer if you see continuous improvement of furnace vacuum level.
Slow cooling is recommended after burnout.
IMPORTANT: The burn-out cycle is always performed with empty furnace. any tooling / fixturing and other equipment must be removed otherwise serious damage of furnace and tooling may occur.
See lessFor your own safety you should follow the OEM manuals.