In comparison to other furnaces the cross fired furnaces can be designed in larger overall dimensions due to the larger firing zone because of the lateral burner arrangement. The only limitation is the furnace width due to crown span length. Typical melting capacities are in between 250 – 500 t/d, but also 750 t/d or even more are possible. Similar to the end fired furnace the regenerative cross fired furnace ensures low energy consumption due to heat recovery system and high flexibility regarding load changes.
The energy consumption of a cross fired furnace is usually slightly higher than that of an end fired furnace.
However, this furnace type can, compared with the end fired furnace, be built with larger melting surfaces because of the lateral arrangement of the port necks. Therefore the cross fired furnace is normally used for furnaces with high capacity or in case the existing building does not allow an end fired furnace.
The regenerators, port necks and burners are positioned laterally. A separate chamber (sectional regenerators) together with an independent flue gas reversal system can be designed for each port neck. This ensures precise control of the furnace temperature over the entire length of the melting furnace. Often the flue gas from multiple port necks or even from all port necks is discharged via one chamber for cost reasons.
In case of environmental restrictions in respect to NOx emissions, this furnace type can be equipped with sideport burners in place of underport burners. Due to limited adjustability and port width, more ports are generally required. Because of the higher number of ports usually one or two regenerators are built on each side of the furnace in this case.
The regenerator chambers can be equipped with different checker types and qualities according to the position of each port. This facilitates the implementation of a furnace suitable for the raw materials used, with a long life and achieving the perfect melting process. A weir wall built into the bottom of the melting end, which is also called barrier, and a deep refining part increase the flexibility and glass quality.
This furnace type can be also equipped with electric boosting in order to increase melting capacity and flexibility.