The sensitivity of entrained-flow coal gasification diffusion burners to changes in geometry

• Published in: Fuel (Guildford) 1992-05, Vol.71 (5), p.593-604
• Main Authors: Sowa, William A., Hedman, Paul O., Smoot, L.Douglas, Richards, Dale O.
• Format: Article
• Language: English
• Subjects: Applied sciences; coal; diffusion; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Furnaces. Firing chambers. Burners; gasification; Solid and pulverized fuel burners and combustion chambers
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/0016-2361(92)90159-L

Three axisymmetric diffusion flame burners were designed and installed on a laboratory-scale, downfired, entrained-flow, coal gasifier operated at pressures up to 560 kPa. Each burner was studied by varying reactor pressure, oxygen coal ratio and steam coal ratio. The gasifier performance was assessed by collecting space-resolved gas and char samples in the reaction chamber and analysing them for carbon conversion, gas composition (CO, CO 2, H 2, H 2O and CH 4) and cold gas efficiency. Burner geometry affected carbon conversion, gas composition and cold gas efficiency. Each burner had unique flame structural characteristics which resulted in burner-unique trends with reactor pressure, oxygen coal ratio and steam coal ratio. At 560 kPa, diffusion flame burner performance approached premixed flame performance. The results from this study suggest that it might be possible to design a diffusion burner that outperforms a fuel-oxidant premixing burner for some operating conditions due to its flame structure and its characteristic energy transfer to the chamber. Performance characteristics of diffusion burners correlated with system pressure, oxygen coal ratio or steam coal ratio cannot be generalized into trends representative of all diffusion flame burners.