Numerical model to simulate the Ti(C,N) protection layer in the blast furnace hearth

It is well understood that the erosion of the hearth refractories is by part a major limitation of the longevity of the blast furnace. Addition of titania via burdening or tuyere injection increases the titanium content in the molten pig iron and is believed to promote the so-called titanium-rich scaffold on the hearth surface, to protect the hearth from subsequent erosion. However, control of the titanium-rich scaffold is challenging as furnace operating condition makes it impossible to visualise and make direct measurements of the complex process. Aimed to improve operational control, this thesis presents a series of numerical models. Firstly, an improved 3D Computational Fluid Dynamics (CFD) model is developed to simulate the flow and heat transfer phenomena in the hearth. The model is validated by comparing the calculated temperatures with the thermocouple data available, where agreements are established within +-3 %. Through extensive parametric studies, an accurate prediction of the flow and temperature distribution in the hearth is been made possible. Secondly, a 2D two-phase multi-component CFD model is used to study the complex transport phenomena associated with the formation and dissolution of solid particles in the hearth. It is found that the isotherm of the equilibrium temperature of the incoming hot metal solution can be used as an excellent indicator to locate the extent of titanium compound particles. This shows that the particles in the hearth can be managed by adjusting this isotherm location by (a) altering the titanium dosage and/or (b) altering the hot metal pool temperature. Finally, a 3D multi-component CFD model is developed to simulate the transport of titanium carbide particles in the blast furnace hearth during titania addition via burdening or tuyere injection. The effects of key operational parameters are investigated. Based on the results of 105 cases, a program that instantly presents graphical images of the TiC particle distribution along the bottom surface of the hearth of PK5BF of any operational condition set by the user is developed. The work carried out in this thesis provides useful information for blast furnace operators during the practice of titania addition.

Grantor dc:publisher

UNSW, Sydney

Year dc:date

2014

Author dc:creator

• Komiyama, Keisuke

• titania addition
• Blast Furnace
• Ti (C,N) Protection Layer
• CFD
• Hearth

Statement dc:rights

• open access
• CC BY-NC-ND 3.0
• free_to_read

Licence

• https://purl.org/coar/access_right/c_abf2
• https://creativecommons.org/licenses/by-nc-nd/3.0/au/

Language dc:language

EN

Identifier

https://doi.org/10.26190/unsworks/2616

OAI identifier oai:identifier

oai:unsworks.library.unsw.edu.au:1959.4/53815