Gas–powder flow and powder accumulation in a packed bed

Dong, Xiaohu; Pinson, David; Zhang, S.J.; Yu, Aibing; Zulli, Paul

doi:10.1016/j.powtec.2004.09.040

Cited by 34 publications

(25 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this case, the so-called powder accumulation region can be observed in a laboratorial scale apparatus. 24) This is shown in Fig. 10, where a CZ is represented by a series of blocks.…”

Section: Model Findingsmentioning

confidence: 99%

“…In the past decade or so, significant progress has been made to overcome these deficiencies, mainly as a result of the rapid development of computer and computational technologies. For example, mathematical models have been developed to describe the localized flow of liquids in the cohesive zone and deadman, 16,17) solid flow in the raceway and down to the furnace hearth, [18][19][20][21][22] abnormal flows such as burden hanging, 23) powder flow and accumulation, 24) and liquid flooding. 25) Process modelling has also been developed rapidly: now the BF ironmaking can be modelled as a three-dimensional transient process.…”

Section: Introductionmentioning

confidence: 99%

“…In order to overcome these deficiencies, various experimen- ISIJ International, Vol. 47 (2007) tal 24,40,[100][101][102][103][104] and numerical 21,38,[40][41][42]96,[105][106][107][108][109] efforts have been made by various investigators in recent years. …”

mentioning

confidence: 99%

“…This region is referred to as the powder accumulation region, which has the maximum powder holdup and will not allow any powder to penetrate. 24) In order to determine this accumulation region and gas-powder flow simultaneously, a solution technique has been proposed to treat the region as part of the boundary for powder phase. 41) …”

mentioning

confidence: 99%

“…However, the inclined angle of the CZ has a significant effect because of the changes in permeability and area for gas flow. 24) An attempt has been made to extend the approach to BF operation. The calculated total powder holdup distribution is shown in Fig.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Modelling of Multiphase Flow in a Blast Furnace: Recent Developments and Future Work

et al. 2007

View full text Add to dashboard Cite

An ironmaking blast furnace is a complex multiphase flow reactor involving gas, powder, liquid and solid phases. Understanding the flow behaviour of these phases is of paramount importance to the control and optimization of the process. Mathematical modelling, often coupled with physical modelling, plays an important role in this development. Yagi 1) gave a comprehensive review of the early studies in this area in 1993. Significant progress has since been made, partially driven by the needs in research but mainly as a result of the rapid development of computer and computational technologies. This paper reviews these developments, covering the formulation, validation and application of mathematical models for gas-solid, gas-liquid, gas-powder and multiphase flows. The need for further developments is also discussed.KEY WORDS: ironmaking; blast furnace; multiphase flow; two fluid model; discrete element method. Review development. Mathematical ModellingGenerally speaking, the existing approaches to modelling the multiphase flow in a BF can be classified into two categories: continuum approach at a macroscopic level and discrete approach at a microscopic level. In the continuum approach, phases are generally considered as fully interpenetrating continuum media and described by separate conservation equations with appropriate constitutive relations and interaction terms representing the coupling between phases. The general governing equations are based on the so-called two fluid model (TFM), originally developed for gas-particle flow, [29][30][31] given by:Conservation The so-called Model A and Model B result from the treatment of the fluid pressure. For example, for gas-solid flow, Model A assumes the pressure is shared between the two phases, while in Model B, the pressure is attributed to gas phase only. 31) Model A formulation has been widely used in multiphase modelling, especially in process metallurgy. Model B formulation was recently used in the so called combined continuum and discrete method for coupled flow of continuum fluid and discrete particles. 32) The continuum approach is suitable for process modelling and applied research because of its computational convenience and efficiency. Indeed, most of the BF modelling is based on this approach. However, its effective use heavily depends on constitutive or closure relations and the momentum exchange between phases. For Newtonian fluids (gas and liquid here), these relations can be readily determined. For non-Newtonian fluids such as solids and powder, general theories are not yet available. In the past, various theories have been devised for different flow regimes (three flow regimes have been identified: quasi-static regime, rapid flow regime and a transitional regime that lies inbetween). For example, models have been proposed to derive the constitutive equations for the rate-independent deformation of granular materials based on either the plasticity theory or the double shearing theory; the rapid flow of granular materials has been described by extend...

show abstract

“…In this case, the so-called powder accumulation region can be observed in a laboratorial scale apparatus. 24) This is shown in Fig. 10, where a CZ is represented by a series of blocks.…”

Section: Model Findingsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Modelling of Multiphase Flow in a Blast Furnace: Recent Developments and Future Work

et al. 2007

View full text Add to dashboard Cite

show abstract

Quantification of powder holdups in the presence of a cavity with lateral gas–powder injection in a packed bed

et al. 2022

View full text Add to dashboard Cite

The lateral flow of gas–powder through a packed bed in a cold model is studied to understand the flow and holdup behaviour of powder in the presence of a cavity, nozzle (tuyere) protrusion, and decreasing gas condition, a system used in the ironmaking blast furnace. Experiments conducted in the current study included a two‐dimensional (2D) slot‐type packed bed. A previously published mass balance and elutriation velocity concept formed the basis for accurately quantifying the static and dynamic powder holdups. Experiments conducted under different conditions such as powder size and flux, gas flow rate, and packed particle density and size resulted in quantifying the powder holdups. The pressure drop in both horizontal and vertical directions is studied in all two‐phase flow experiments. The formation of the static holdup with time in the packed bed is studied. The reproducibility of the experiments was confirmed. The static holdup inside the packed bed at various locations along the vertical direction (i.e., height) is also quantified. The static holdup correlation developed based on experimental data resulted in a 95% confidence interval. Static powder holdup increases with a decrease in the superficial gas velocity, an increase in the size of the powder particle, and powder flux. Dynamic holdup also showed a similar trend.

show abstract

Gas‐solid Two‐phase Mixtures Flowing Upward through a Confined Packed Bed

Cong

Ding

2006

Part & Part Syst Charact

View full text Add to dashboard Cite

This paper deals with flows of a gas-solid two-phase mixture through a confined packed bed. Both experimental work and numerical modelling are performed on the behaviour of suspended particles within the packed bed. The experimental work is carried out with a non-intrusive Positron Emission Particle Tracking (PEPT) technique, which tracks particle motion at the single particle level for a prolonged period thus allows both the microscopic and macroscopic solids behaviour to be analysed under the steady-state conditions. A continuous based model is used to simulate the flow behaviour. The model uses a newly proposed porosity model and treats the sus-pended and packed particles as a binary mixture with the packed particles being at zero velocity. The results show that the model captures the main features of solids behaviour in terms of the radial distributions of the suspended particle concentration and the axial solids velocity. Both the experiments and modelling suggest that the wall effect on the motion of suspended particles be limited to a small region close to the wall (∼0.5-1 packed particle diameter). However, deviations exist between the model predictions and experiments; more work is therefore proposed to improve the interaction terms in the model between the suspended and packed particles.

show abstract

Gas–powder flow and powder accumulation in a packed bed

Cited by 34 publications

References 20 publications

Modelling of Multiphase Flow in a Blast Furnace: Recent Developments and Future Work

Modelling of Multiphase Flow in a Blast Furnace: Recent Developments and Future Work

Quantification of powder holdups in the presence of a cavity with lateral gas–powder injection in a packed bed

Gas‐solid Two‐phase Mixtures Flowing Upward through a Confined Packed Bed

Contact Info

Product

Resources

About