In the center of the glass melting tank, 25 mm lower than the electrofused cast sole, there is a draining hole of about 35 mm diameter.
The drilled electrofused cast block is fixed 25 mm lower than the sole of the tank, and its thickness is 150 mm.
The drain opening is controlled by a steel water cooled plunger, installed with a mechanical system.
The draining can be used for the complete emptying of the furnace or for taking out a part of the glass.
During the glass drainage of the furnace, the glass flow from the furnace can be open and close by the water cooled plunger mechanism.