In accordance with the energy saving program worked out by the personal initiative of the Chairman of the Board of Zaporizhstal JSC V.A. Satskiy, introduction of new jet-niche burners in the open-hearth furnace shop, blast furnace shop and sintering plant went on in 2008. The jet-niche technology for fuel combustion, with controlled flow of fuel and oxidizer is based on uniform distribution of gas in the air flow with the formation of a stable swirling structure providing mixture formation and combustion stabilization with self cooling of the burner module. The burners provide intensive stable burning with a short flame at a considerable fluctuation of gas pressure in the network; optimal coefficient of air excess in the burner device; reduction of heat losses and increase of coefficient of efficiency; provision of ecological indices less than the maximum allowed. This technology corresponds to European ecological norms.
For Zaporizhstal shops according to technical assignments of the Works “Spetsgazprom” has developed several types of burners: СНГ-33М for furnace roofs ДСПА-1, СНГ-33ВС for roofs of open-hearth furnaces, СНГ-21 for mixers and СНГ-22 for drying of steel pouring ladles in the open-hearth furnace shop, СНГ-22АГ for sintering machines and drying of hot-metal ladle cars in the blast furnace shop. For each type of burners and each type of thermal generating units thermal conditions have been worked out. The usage of jet-niche burners in shops only in 2008 allowed to reduce the consumption of natural gas by 35809.76 thousand m3 (41181 tons of fuel equivalent) and reduce the expenditures by 22.907 mln UAH.
In 2009 this work went on. On open-hearth furnaces Nos. 2,5,7,8 and 10 new jet-niche burners СНГ-55СВ for end heating of the open-hearth furnaces have been installed. The old gas burners of an old design with oxygen conversion for heating the working area did not provide in full volume effective combustion of fuel. Due to the large size of the furnaces and consumption of natural gas and air, the mixing process was not enough. To eliminate incomplete burning of fuel excess air was added into the furnace. Apart from that the above mentioned conversion burners do not provide required inflexible flame and flame length with natural gas pressure less than 2kgf/cm2. The new jet-niche burner type СНГ-55СВ reduces the consumption of natural gas by 500 m3/hour at reduced pressure of natural gas 2-3 times. Research conducted on open-hearth furnaces showed that the temperature of the regenerator checkerwork has increased up to 10000C against 9700C, providing better heating of the regenerative air. The temperature in the furnace flue increased up to 6900C against 6700C. The pressure in the furnace increased, reducing the leak-in of cold air into the furnace.
The content of oxygen in the exhaust gases has reduced to 5.2% against 11.0%. In this case complete combustion of fuel takes place in the working area of the furnace because the content of carbon oxide in the exhaust gases amounts to 0%.
In March 2009 in the open-hearth furnaces during operation of the burners at pressure of gas 1.6-1.7 kgf/cm2 economy of natural gas up to 6.6 kg equivalent fuel/ton has been achieved.
The application of jet-niche burners on the roofs and for heating the ends of open-hearth furnaces is a considerable scientific and technical thermal technical improvement of these metallurgical aggregates, which has been implemented thanks to the joint work of the open-hearth furnace specialists and all the engineering services of the Works.