Studies on the decarburization of the commercial Submerged Entry Nozzles
2011 (English)In: Steel Grips - Journal of Steel and Related Materials, ISSN 1611-4442, Vol. 9Article in journal (Refereed) Published
Decarburization behaviors of Al2O3-C, ZrO2-C and MgO-C refractory materials constituting a commercial Submerged Entry Nozzle (SEN), have been investigated in different gas atmosphere consisting of CO2, O2 and Ar. The (CO2/O2) ratio values were kept the same as it is in propane combustion flue gas at Air Fuel Ratio (AFR) values equal to 1.5 and 1 for both Air-fuel and Oxygen-fuel combustions. Laboratory experiments were carried out nonisothermally in the temperature range 873 K to 1473 K at 15 K/min followed by isothermal heating at 1473 K for 60 min. The decarburization ratio (α) values of the three refractory types were determined by measuring the weight losses of the samples. The results showed that the decarburization ratio (α) values of the MgO-C refractory became 3.1 times higher for oxygen-fuel combustion compared to air-fuel combustion both at AFR equal to 1.5 in the temperature range 873 K to 1473 K. The decarburization ratio (α) values for Al2O3-C samples were the same as for the isothermal heating at 1473 K and non-isothermal heating in the temperature range 1473 K to 1773 K with a 15 K/min heating rate. It substantiates the SEN pre-heating advantage at higher temperatures for shorter holding times instead of heating at lower temperatures for longer holding times. Jander’s diffusion model was proposed for estimating the decarburization rate of Al2O3-C refractory in the SEN. The activation energy for Al2O3-C samples heated at AFR equal to 1.5, for air-fuel and oxygen-fuel combustions were found to be 84.5 KJ/mol and 95.5 KJ/mol respectively during non-isothermal heating in the temperature range 873 K to 1473 K.
Place, publisher, year, edition, pages
2011. Vol. 9
Al2O3-C, ZrO2-C; MgO-C, decarburization, reaction mechanism.
Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-25100DOI: 10.5161/steel/2011/g02349OAI: oai:DiVA.org:kth-25100DiVA: diva2:355767
QC 20101008 Uppdaterad från Manuskript till Artikel2010-10-082010-10-082011-10-14Bibliographically approved