Q. Compare pot furnace and tank furnace used in manufacture of glass.
Used for special glasses, optical glasses, art glass and plate glass etc.
Used for large scale production, such as common glasses
As pots in pot furnace can be stirred, a great uniformly, as is required in optical glass, is achieved.
Stirring is not possible
As pots are closed, glass melt is completely protected from combustion products impurities as required for special glasses.
Not completely protected so special glass cannot be obtained
Process is discontinuous. Shaping of the articles from glass melt is done at temperature somewhat lower than fusion temperature.
Process is continuous. The charging, melting and for shaping is carried out simultaneously a temperature is maintained.