For existing furnaces with unchanged staffing, REBOX® offers efficient solutions providing increased production capacity and flexibility, decreased fuel costs and lowered emissions of carbon dioxide, NOx and SOx. REBOX has also been successfully applied in new furnaces.
REBOX offers more capacity with less emission to any new or existing furnace by:
- Throughput (tonnes/hour) increased up to 50%
- Fuel savings up to 50%
- Corresponding to a 50% reduction of CO2
- NOx emissions below 70 mg/MJ.
Experience and technical lead
Since 1990, Linde has supplied 115 REBOX oxyfuel based solutions to batch and continuous reheat furnaces for rolling mills and forge shops as well as for annealing furnaces. Linde has not only the experience from all these installations, but is also a forerunner in combustion technology development in this area. State of the art technologies including so called Flameless Combustion and Direct Flame Impingement have been brought to full scale installed customer solutions since 2002.
Oxyfuel has no nitrogen ballast
Combustion is all about fuel, oxygen and ignition. Air contains only 21% oxygen, the remaining 79% is ballast, practically nitrogen. In combustion processes, all this ballast is negative, it does not take part in the combustion, but has to be heated up, consuming unnecessary extra fuel. The ballast also has to be transported by electrical blowers, through oversized ducting and burners in long furnaces and flue gas systems that are much larger in size than with using only oxygen. This has a negative impact on the capital requirements and using air will substantially increase the production of NOx.
It has been clearly demonstrated in practice that if oxygen, not air is used to combust a fuel, all the heat transfer mechanisms, convection, conduction and radiation, can be promoted at the same time. This results in a faster, more even heating process, which cuts the total heating time thus allowing for more production capacity and flexibility. The flue gas volumes are reduced by up to 80% with no more need for bulky flue gas systems or recuperators.
Turnkey and complete scope of supply
Linde has the experience and organisation to deliver complete turnkey installations including engineering, project management, installation and commissioning.
The REBOX portfolio includes equipment and control systems for oxygen-enrichment, oxygen-lancing, oxyfuel-boosting and 100% oxyfuel operation in reheat furnaces and annealing lines.
Linde develops and produces powerful, compact and rugged oxyfuel burners needed to retrofit in existing furnaces. The efficient oxyfuel technology makes it possible to replace a 2 MW airfuel burner with a more compact REBOX burner of 1.3 MW, still allowing for an increased production capacity.
The control system handles all aspects of operation, safety, optimum heating and energy usage.
