2 to 4 burners at each port and the regenerator chambers are connected at the rear wall side of the superstructure. The combustion of fuel and preheated air from one regenerator chamber takes place - flames starting from the burner nozzles and extending almost over the length of the furnace making a U turn before the front wall. Due to longer residence time of combustion gases there are less structural heat losses compared to cross fired regenerative furnaces.
Low level oxygen enrichment of combustion air is the simplest form of using oxygen in glass melting applications typically applied for furnaces near the end of the campaign for furnaces having either regenerator plugging / partial collapse or a recuperator leakage. The lower volume of offgases gives the posibility to combust additional fuel and optimise the production. The limitation is given by the oxygen compatibility of material downstream from the enrichment point and by the high oxygen volumes neded due to the fact that it goes to all burners. The air burner flames are shortened and the flame temperature is increased.
Oxygen lancing is used in similar situations to enrichment. It gives a possibility to introduce the oxygen additional to the existing air / fuel burner. In most cases it is done by undershot, where it enriches selectively the underside of the conventional flame, thereby concentrating extra heat downward toward the material being heated. In case of oxygen enriched air staging it can be used for optimisation of NOx levels.
Oxyfuel boost technology is primarily used in glass furnaces to:
- Increase furnace pull rates
- Improve product quality
- Extend furnace life by preventing / correcting regenerator checker failures
- Extend furnace life due to failing recuperator
- Optimise pollutant emission levels
The difference between oxyfuel boosting and enrichment/lancing is that in addition to the injection of oxidant there is the addition of fuel and the additional aim is to increase pull rate and/or glass quality. In case of oxyfuel boosting (or partial conversion) are the high efficient oxyfuel burners positioned there where the heat is mostly needed in the furnace – either in the charging end or the hot-spot position.
Hot-spot boosting can be applied to all types of furnaces. It typically involves positioning two oxyfuel burners at a furnace’s hot spot in order to enhance glass convection currents, which improve residence time and increase quality. The furnace throughput can be increased by up to 10% and the electrical boost can be balanced. Depending on the demand the boosting can be switched off at lower tonnage.
Boosting at zero-port with oxyfuel technology for crossfired furnaces is the technical standard today, reaching up to 10-15% of additional pull rate and improved glasss quality.
Oxipyr - F
Oxipyr - Flat
Oxipyr - Flex3
Oxipyr - P / P LON
Oxipyr - Advanced regulation
Oxipyr - Basic+, Basic regulation
Oxipyr - 400 regulation