Effect of Natural Gas Flow Rate and Temperature on the Processes Occurring in a Blast Furnace Air Tuyere with a Heat-Insulating Insert in the Blast Channel

• Published in: Steel in translation 2022-11, Vol.52 (11), p.1020-1026
• Main Authors: Albul, S. V., Kobelev, O. A., Radyuk, A. G., Titlyanov, A. E., Levitskii, I. A.
• Format: Article
• Language: English
• Subjects: Blast furnace gas; Blast furnace practice; Burnout; Chemistry and Materials Science; Combustion; Completeness; Flow velocity; Gas flow; Gases; Heat; Heating; Inserts; Materials Science; Natural gas; Tuyeres
• ISSN: 0967-0912; 1935-0988
• DOI: 10.3103/S0967091222110031

The purpose of this work is to analyze the effect of a heat-insulating insert, as well as the flow rate and temperature of natural gas on the processes occurring in the blast channel of an air tuyere of a blast furnace. The paper analyzes the results of industrial and numerical experiments obtained by different researchers on the use of various methods for increasing the completeness of the combustion reaction within the air tuyere of natural gas (NG) fed into it: increasing the NG injection rate and its temperature, using of heat-insulating inserts installed in the inner cylinder of the air tuyere. Using the Ansys Fluent software package, the influence of a heat-insulating insert and an increase in NG consumption on the temperature and composition of gases leaving the tuyere of blast furnace No. 5 of Severstal PJSC was studied. It was found that with an increase in the NG flow rate from 0.283 to 0.328 kg/s, the temperature of the gaseous medium at the tuyere outlet decreases by 6°C for the variant without an insert and increases by 3°C for the variant with an insert. When studying the effect of a heat-insulating insert and an increase in NG temperature (in different combinations) on the processes occurring in the tuyere, it was found that the temperature of the gaseous medium at the tuyere outlet in the case of using a heat-insulating insert without NG heating is slightly higher than when NG is heated to 200°C without insert. However, the effect of NG heating in the presence of an insert is significantly higher than without it, due to the mutual strengthening of two factors affecting the completeness of NG combustion within the tuyere, accompanied by protection of the tuyere inner nozzle from burnout.