The semi-sealed convection oven is used for heat treatment of oxygen-sensitive metal parts. During heating and cooling via cool water, the oven atmosphere is flushed with inert gas.
Process description: The operator feeds the frames featuring the parts to the oven. After closing the oven lifting door, the operator starts the desired tempering program.
Prior to starting the heating ramp, the oven atmosphere is flushed with inert gas to lower the oxygen content in the oven below a set target value.
After dropping below this value, the heating ramp starts. During the complete tempering process, the oxygen content is monitored and regulated by additional supply of inert gas in the oven interior.
To cool off the semi-sealed oven, air-thermal oil is used on the interior, and thermal oil-water heat exchanger is used outside of the oven. At the end of the cooling ramp, the oven interior is flushed with compressed air to raise the oxygen content of the oven atmosphere to a value that is acceptable for people. This enables the operator to open the lifting door of the oven without danger to remove the tempered batch.