Pot furnace is a type of batch-type glass melting furnace. It is mainly used for melting a small amount of high quality glass. 

It mainly consists of the working chamber, flame tube (small furnace), combustion chamber, a heat exchanger ( or regenerator). The pot is placed in the working chamber. The raw materials are put into a pot and then heated in the pot. When the glass is melt, the molten glass is cast into the designed products. Its advantage is that the glass liquid does not directly contact the furnace lining. 

 

According to the way of heat exchange, the pot furnace can be divided into regenerative furnace and recuperative furnace. According to the direction of flame, it can be classified into down draft type, flat flame type and united flame type. Based on the number of pots, it can be categorized into single-pot furnace, double-pot furnace and multi-pot furnace. Single-pot furnaces are usually used to melt optical glass, while multi -pot furnaces is usually for melting lead glass. 

 

The pot is usually made of SiO2-Al2O3 refractory materials. It has a bulk density of 2.02-2.08g/cm3, apparent porosity 20%, and linear shrinkage on reheating 0.3%. The service of the open pot is 36-90 times, while the service life of the close pot is about 36 times. 

 

The selection of refractory materials depends on the type of glass. For corrosive optical glass, refractory materials with good corrosion resistance, such as high alumina, high silica and mullite, are used. For common pot furnaces, high quality fire clay brick and silica brick are used. 

 

As pots are closed, molten glass is completely protected from combustion impurities. It is mainly used for melting a small amount of high quality glass, such as special glasses, optical glasses, chemical glass, art glass and plate glass etc.