Peter Richard Austin

Three-Dimensional Modeling of Flow and Thermochemical Behavior in a Blast Furnace

An ironmaking blast furnace (BF) is a complex high-temperature moving bed reactor involving counter-, co- and cross-current flows of gas, liquid and solid, coupled with heat and mass exchange and chemical reactions. Two-dimensional (2D) models were widely used for understanding its internal state in the past. In this paper, a three-dimensional (3D) CFX-based mathematical model is developed for describing the internal state of a BF in terms of multiphase flow and the related thermochemical behavior, as well as process indicators. This model considers the intense interactions between gas, solid and liquid phases, and also their competition for the space. The model is applied to a BF covering from the burden surface at the top to the liquid surface in the hearth, where the raceway cavity is considered explicitly. The results show that the key in-furnace phenomena such as flow/temperature patterns and component distributions of solid, gas and liquid phases can be described and characterized in different regions inside the BF, including the gas and liquids flow circumferentially over the 3D raceway surface. The in-furnace distributions of key performance indicators such as reduction degree and gas utilization can also be predicted. This model offers a cost-effective tool to understand and control the complex BF flow and performance.

An Integrated Model of Coal/Coke Combustion in a Blast Furnace

A three‐dimensional integrated mathematical model of the combustion of pulverized coal and coke is developed. The model is applied to the region of lance‐blowpipe‐tuyere‐raceway‐coke bed to simulate the operation of pulverized coal injection in an ironmaking blast furnace. The model integrates two parts: pulverized coal combustion model in the blowpipe‐tuyere‐raceway‐coke bed and the coke combustion model in the coke bed. The model is validated against the measurements in terms of coal burnout and gas composition, respectively. The comprehensive in‐furnace phenomena are simulated in the raceway and coke bed, in terms of flow, temperature, gas composition, and coal burning characteristics. In addition, underlying mechanisms for the in‐furnace phenomena are analyzed. The model provides a cost‐effective tool for understanding and optimizing the in‐furnace flow‐thermo‐chemical characteristics of the PCI process in full‐scale blast furnaces.

Modeling of internal state and performance of an ironmaking blast furnace: Slot vs sector geometries

AbstractMathematical modeling is a cost-effective method to understand internal state and predict performance of ironmaking blast furnace (BF) for improving productivity and maintaining stability. In the past studies, both slot and sector geometries were used for BF modeling. In this paper, a mathematical model is described for simulating the complex behaviors of solid, gas and liquid multiphase flow, heat and mass transfers, and chemical reactions in a BF. Then the model is used to compare different model configurations, viz. slot and sector geometries by investigating their effects on predicted behaviors, in terms of two aspects: (i) internal state including cohesive zone, velocity, temperature, components concentration, reduction degree, gas utilization, and (ii) performance indicators including liquid output at the bottom and gas utilization rate at the furnace top. The comparisons show that on one hand, predictions of internal state of the furnace such as fluid flow and thermo-chemical phenomena using the slot and sector geometries are qualitatively comparable but quantitatively different. Both sector and slot geometries give a similar cohesive zone shape but the sector geometry gives a higher cohesive zone near the wall and faster reduction. On the other hand, the two geometries can produce similar performance indicators including gas utilization at the furnace top and liquid output at the bottom. Such a study is useful in selecting geometry for numerically examining BF operation with respect to different needs.

Modelling ironmaking blast furnace: Solid flow and thermochemical behaviours

Ironmaking blast furnace is a counter-, co-, cross-current moving bed reactor, where solid particles are charged at the furnace top forming a downward moving bed while gas are introduced at the lower part of furnace and travels upward through the solid bed of varying porosity, reducing solid ore to liquid iron at the cohesive zone. These three phases interact intensely. In this paper, a three-dimensional mathematical model is developed. The model describes the motion of solid and gas, based on continuum approach, and implements the so-called force balance model for the liquid flow. The model is applied to a blast furnace, where raceway cavity is considered explicitly. The results demonstrate and characterize the key multiphase flow patterns of solid-gas-liquid at different regions inside the blast furnace, in particular solid flow and associated thermochemical behaviours of solid particles. This model offers a costeffective tool to understand and optimize blast furnace operation.

Modelling the combustion of charcoal in a model blast furnace

The pulverized charcoal (PCH) combustion in ironmaking blast furnaces is abstracting remarkable attention due to various benefits such as lowering CO2 emission. In this study, a three-dimensional CFD model is used to simulate the flow and thermo-chemical behaviours in this process. The model is validated against the experimental results from a pilot-scale combustion test rig for a range of conditions. The typical flow and thermo-chemical phenomena is simulated. The effect of charcoal type, i.e. VM content is examined, showing that the burnout increases with VM content in a linear relationship. This model provides an effective way for designing and optimizing PCH operation in blast furnace practice.

A 3D CFD simulation of liquid flow in an ironmaking blast furnace

A three-dimensional CFX-based mathematical model is developed to describe the flow-heat transfer-chemical reactions behaviours of gas-solid-liquid phases in an ironmaking blast furnace (BF), where the raceway cavity is considered explicitly. The typical in-furnace phenomena of an operating blast furnace, in particular, the liquid flow in the lower part of a blast furnace is simulated in aspects of velocity and volume fraction. This model offers a cost-effective tool to understand and optimize blast furnace operation.