Energy Efficiency: regenerative burners advantages

The heating process in a smelting plant is a key factor in optimisation. Combustion heating is the source of the process emissions to the atmosphere. Opting for a heating system with regenerative burners improves energy efficiency, compared to conventional air-gas mixture burners in the nozzle, reducing its carbon footprint and greenhouse gas emissions into the atmosphere.

The regenerative burners were designed with the idea of improving combustion performance, with greater use of the heat of the fumes for preheating the combustion air. This utilisation is much more efficient than with conventional heat exchangers. We are talking about heating chambers at 1100-1150ºC, where we extract fumes to atmosphere at temperatures below 250ºC and preheat ambient air for combustion, up to 700ºC.

The regenerative burners work in pairs. When burner Q1 is combusting, its partner Q2 is sucking in the gases from the furnace and temporarily storing the heat of the fumes in a bed formed by ceramic balls or honeycombs. After a certain time (40-60s), the cycle is reversed and burner Q1 switches to fume aspiration mode and Q2 switches to combustion mode, passing the cold air through the hot ceramic bed, preheating the combustion air, thus extracting the heat from the ceramic bed and returning it to the combustion process.

The result is that the waste gases from the kiln are used for efficient preheating of the air, which results in lower energy consumption, reduced flue gas volume and reduced flue gas temperature.

Regenerative burners are capable of recovering 70-85% of the heat from the flue gases generated. They allow a reduction of up to 50% in energy consumption, improve the overall efficiency of the plant and reduce its carbon footprint.