The recuperative heated furnace is characterised by the preheating of the combustion air through recuperators. These recuperators are normally made of steel and may be double shell or tube bundle type recuperators. Specially developed air casing burners are used in this type of furnace to ensure an equal distribution of the combustion air around the burner lances.
The furnace can be designed as cross fired or end fired type. At the end fired type system the waste gas outlet opening is located above the burners in order to have the flame in a shape of a horizontal standing “U”. At the cross fired type the waste gas opening can be situated at the front wall as well as at the side wall.
The recuperative furnaces are normally used for glass melting between 4 – 60 t/d, in some special cases also up to 400 t/d. Typical for this type of furnace is the low melting area load and low investment.
Recuperative furnaces are typically used for the production of container glass, table ware, lead crystal glass, sodium-silicate glass, fibre glass, tubes and bulbs.