# Numerical Simulation of the Raceway Zone in Melter Gasifier of COREX Process

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## Abstract

**:**

## 1. Introduction

## 2. Mathematical Model

#### 2.1. The Basic Assumptions of This Paper

- (1)
- In each location of the flow field, the particulate phase coexists with the gas phase and both penetrate each other, with each phase having its own velocity, temperature, and volume fraction, but the particles of each size group have the same velocity and temperature.
- (2)
- Each particle phase (size group) has a continuous distribution of velocity, temperature, and volume fraction in space.
- (3)
- Each particle phase and gas phase, in addition to quality, momentum, and energy interactions, also has its own turbulence.
- (4)
- The initial size distribution is used to distinguish the particle groups.
- (5)
- For dense particle suspensions, particle collision can cause additional particle viscosity, diffusion, and heat conduction. A two-fluid model is used in the study (also called Eulerian model).

#### 2.2. Volume Fraction

_{q}) is defined as

_{q}is the physical density of the q phase.

#### 2.3. Mass Conservation Equation

#### 2.4. Momentum Conservation Equation

#### 2.5. Conditions

^{−5}. The main parameters used in the model are shown in Table 1.

## 3. Results

#### 3.1. Unsteady Simulation of the Raceway Formation Process

#### 3.2. Effect of the Velocity of the Blowing Gas on the Cavity Size of the Raceway

## 4. Conclusions

- (1)
- As the gas continues to inject, the cavity first grows deep into the furnace. After reaching a certain depth, the cavity begins to develop upwards, and the cavity volume increases. The time taken from the start of the gas to the formation of the stable raceway shape is short, and then the depth and height of the raceway and the volume of the cavity are stable for a long period of time.
- (2)
- Under the condition that the normal blowing speed of the COREX melter–gasifier is 250 m/s and the blowing angle is 4°, the depth of the raceway is about 950 mm, and the shape of the raceway is approximately semi-elliptical.
- (3)
- As the velocity of the tuyere gas injection increases, the depth and height of the raceway increase, and the volume of the cavity in the raceway zone increases as it stabilizes, but the shape of the raceway does not change significantly.

## Author Contributions

## Funding

## Conflicts of Interest

## References

- Anameric, B.; Kawatra, S.K. Direct iron smelting reduction processes. Miner. Process. Extr. Metall. Rev.
**2008**, 30, 1–51. [Google Scholar] [CrossRef] - Qu, Y.X.; Zou, Z.S.; Xiao, Y.P. A Comprehensive Static Model for COREX Process. ISIJ Int.
**2012**, 52, 2186–2193. [Google Scholar] [CrossRef] - Zhou, H.; Wu, S.L.; Kou, M.Y.; Luo, Z.G.; He, W.; Zou, Z.S.; Shen, Y.S. Discrete Particle Simulation of Solid Flow in a Large-Scale Reduction Shaft Furnace with Center Gas Supply Device. ISIJ Int.
**2018**, 58, 422–430. [Google Scholar] [CrossRef] - Kumar, P.P.; Gupta, P.K.; Ranjan, M. Operating experiences with Corex and blast furnace at JSW Steel Ltd. Ironmak. Steelmak.
**2008**, 35, 260–263. [Google Scholar] [CrossRef] - Zhou, H.; Wu, S.L.; Kou, M.Y.; Yao, S.; Shen, Y.S. Analysis of Coke Oven Gas Injection from Dome in COREX Melter Gasifier for Adjusting Dome Temperature. Metals
**2018**, 8, 921. [Google Scholar] [CrossRef] - Di, Z.X.; Luo, Z.G.; Zou, Z.S. Fractal study on raceway boundary. J. Iron Steel Res. Int.
**2011**, 18, 16–19. [Google Scholar] [CrossRef] - Gupta, G.S.; Rudolph, V. Comparison of blast furnace raceway size with theory. ISIJ Int.
**2006**, 46, 195–201. [Google Scholar] [CrossRef] - Hatano, M.; Fukuda, M.; Takeuchi, M. An experimental study of the formation of raceway using a cold model. Tetsu Hagane
**1976**, 1, 25–32. [Google Scholar] [CrossRef] - Sastry, G.K.; Gupta, G.S.; Lahiri, A.K. Void formation and breaking in a packed bed. ISIJ Int.
**2003**, 43, 153–160. [Google Scholar] [CrossRef] - Rajneesh, S.; Sarkar, S.; Gupta, G.S. Prediction of raceway size in blast furnace from two dimensional experimental correlations. ISIJ Int.
**2004**, 44, 1298–1307. [Google Scholar] [CrossRef] - Hiroshi, T.; Nobuyuki, K. Cold model study on burden behaviour in the lower part of blast furnace. ISIJ Int.
**1993**, 33, 655–663. [Google Scholar] - Zhou, D.D.; Cheng, S.S.; Zhang, R.X.; Li, Y.; Chen, T. Uniformity and Activity of Blast Furnace Hearth by Monitoring Flame Temperature of Raceway Zone. ISIJ Int.
**2017**, 57, 1509–1516. [Google Scholar] [CrossRef] - Li, Y.; Cheng, S.S.; Zhang, R.X.; Chen, T. Reconstruction of Three-dimensional Temperature Distribution with Radiative Image by Monte Carlo Method in Blast Furnace Raceway. ISIJ Int.
**2017**, 57, 2141–2147. [Google Scholar] [CrossRef] - Zhou, D.D.; Cheng, S.S. Measurement study of the PCI process on the temperature distribution in raceway zone of blast furnace by using digital imaging techniques. Energy
**2019**, 174, 814–822. [Google Scholar] [CrossRef] - Sarkar, S.; Gupta, G.S.; Kitamura, S.Y. Prediction of Raceway Shape and Size. ISIJ Int.
**2007**, 47, 1738–1744. [Google Scholar] [CrossRef] - Frank, H.D.; Tian, F.G.; Chen, N.W. A comprehensive simulation of the raceway formation and combustions. AISTech 2009 Proc.
**2009**, 1, 333–344. [Google Scholar] - Du, S.W.; Chen, W.H. Numerical prediction and practical improvement of pulverized coal combustion in blast furnace. Int. Commun. Heat Mass Transf.
**2006**, 33, 327–334. [Google Scholar] [CrossRef] - Gu, M.Y.; Zhang, M.C.; Selvarasu, N.C. Numerical analysis of pulverized coal combustion inside tuyere and raceway. Steel Res. Int.
**2008**, 79, 17–24. [Google Scholar] [CrossRef] - Shen, Y.S.; Shiozawa, T.; Austin, P.; Yu, A.B. Modelling of injecting a ternary coal blend into a model ironmaking blast furnace. Miner. Eng.
**2016**, 90, 89–95. [Google Scholar] [CrossRef] - Shen, Y.S.; Yu, A.B. Model study of the effect of bird’s nest on transport phenomena in the raceway of an ironmaking blast furnace. Miner. Eng.
**2014**, 63, 91–99. [Google Scholar] [CrossRef] - Hou, Q.F.; E, D.Y.; Yu, A.B. Discrete Particle Modeling of Lateral Jets into a Packed Bed and Micromechanical Analysis of the Stability of Raceways. AIChE
**2016**, 62, 4240–4250. [Google Scholar] [CrossRef] - Hilton, J.E.; Cleary, P.W. Raceway formation in laterally gas-driven particle beds. Chem. Eng. Sci.
**2012**, 80, 306–316. [Google Scholar] [CrossRef] - Wei, G.C.; Zhang, H.; An, X.Z.; Xiong, B.; Jiang, S.Q. CFD-DEM study on heat transfer characteristics and microstructure of the blast furnace raceway with ellipsoidal particles. Powder Technol.
**2019**, 346, 350–362. [Google Scholar] [CrossRef] - Sun, J.J.; Luo, Z.G.; Di, Z.X.; Zhang, T.; Zhou, H.; Zou, Z.S. Definition of Raceway Boundary Using Fractal Theory. J. Iron Steel Res. Int.
**2015**, 22, 36–41. [Google Scholar] [CrossRef] - Sun, J.J.; Luo, Z.G.; Zou, Z.S. Numerical simulation of raceway phenomena in a COREX melter gasifier. Powder Technol.
**2015**, 281, 159–166. [Google Scholar] [CrossRef] - Sun, Y.; Luo, Z.G.; Zou, Z.S.; Liu, H.H. Determining raceway boundary by image processing via high-speed video camera. J. Northeast. Univ. (Nat. Sci.)
**2009**, 30, 1458–1461. [Google Scholar]

Project | Values | Unit |
---|---|---|

Gun inlet diameter | 30 | mm |

Coke bed porosity | 0.60 | - |

Max focal bed porosity | 0.63 | - |

Bed height | 2230 | mm |

Type of blowing gas | Air | - |

Air density | 1.205 | kg/m^{3} |

Air viscosity | 1.76 × 10^{−}^{5} | Pa·s |

Injecting gas velocity | 50–250 | m/s |

Coke diameter | 40 | mm |

Coke density | 600 | kg/m^{3} |

Gas injection inclination | 4 | degree (°) |

Operating pressure | 3.5 | atm |

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## Share and Cite

**MDPI and ACS Style**

Sun, Y.; Chen, R.; Zhang, Z.; Wu, G.; Zhang, H.; Li, L.; Liu, Y.; Li, X.; Huang, Y.
Numerical Simulation of the Raceway Zone in Melter Gasifier of COREX Process. *Processes* **2019**, *7*, 867.
https://doi.org/10.3390/pr7120867

**AMA Style**

Sun Y, Chen R, Zhang Z, Wu G, Zhang H, Li L, Liu Y, Li X, Huang Y.
Numerical Simulation of the Raceway Zone in Melter Gasifier of COREX Process. *Processes*. 2019; 7(12):867.
https://doi.org/10.3390/pr7120867

**Chicago/Turabian Style**

Sun, Ye, Ren Chen, Zuoliang Zhang, Guoxi Wu, Huishu Zhang, Lingling Li, Yan Liu, Xiaoliang Li, and Yan Huang.
2019. "Numerical Simulation of the Raceway Zone in Melter Gasifier of COREX Process" *Processes* 7, no. 12: 867.
https://doi.org/10.3390/pr7120867