5. Operating

5.1 Preheating

Continuous furnaces must be brought up to temperature before the first charges are introduced. The preheating time depends on the furnace's thermal inertia, and must be known in order to plan production and the presence of operating personnel.

If production stoppages are of short duration, it may be advantageous to keep the furnace at temperature. Batch furnaces can also, in certain circumstances (production rate close to furnace capacity or short lead times), be preheated or maintained at or below process temperature.

If the furnace's control system allows, preheating and...