Numerical study of liquid coverage in a gas–liquid–solid packed bed

Du, Wei; Zhang, Lifeng; Lv, Sha; Lu, Pei; Xu, Jian; Wei, Weisheng

doi:10.1016/j.partic.2014.10.013

Cited by 12 publications

(8 citation statements)

References 34 publications

(39 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The velocity field and bubble profile in a vertical gas-liquid slug flow inside the capillaries has been modeled with a VOF technique, and the result was found to be in good agreement with published experimental measurements [15]. In the past two decades, the VOF model has been predominately practiced in the field of CFD simulation of TBRs [6,13,[16][17][18][19][20].…”

Section: Introductionsupporting

confidence: 57%

“…Difference between 0.072 N/m and 0.108 N/m was less significant because most of the inner holes were filled with liquid when the coefficient rose to 0.072 N/m. The rise of wetting efficiency can also be explained by the opinion of Du [6], which declared that the under lower surface tension conditions rivulet flow patterns are found on the particle surface.…”

Section: Contact Anglementioning

confidence: 95%

“…However, local liquid distribution phenomenon on the particle scale such as flow maldistribution, channeling and catalyst wetting can also significantly affect the overall reactor performance (e.g., pressure drop, catalyst use, and reactant conversion). The rigorous mathematical models for calculating them are still tough [6]. The liquid flow textures in a bed consist of several features: liquid film flow, rivulets over the particles, pendular structures, liquid-filled channels, and liquid-filled pockets [7].…”

Section: Introductionmentioning

confidence: 99%

“…Lopes et al proposed a high-resolution CFD approach using discrete particles and designed a TBR with regular positioned catalyst particles for the Euler-Euler [21] and Eulerian VOF simulations [13], and studied the catalytic wet oxidation of phenolic wastewaters in their later studies [22,23]. Du et al performed CFD simulations on regular particles arrangement within a rectangular domain to investigate the local wetting behavior in a TBR [6,16]. Simulations performed by both groups modeled particles with regular configuration and fixed distance between each other, which is difficult to achieve in a real reactor where catalyst particles are packed randomly, and the particle's shape can be complex such as a cylinder or hollow cylinder.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Computational Investigation of Liquid Holdup and Wetting Efficiency Inside Trickle Bed Reactors with Different Catalyst Particle Shapes

et al. 2020

View full text Add to dashboard Cite

Liquid holdup and wetting efficiency are essential parameters for design of trickle bed reactors. Both parameters play an important role in reactor performance including pressure drop, conversion, and heat transfer. Empirical formulas are usually employed to calculate liquid holdup and wetting efficiency. However, factors such as particle shape and the wetting ability of liquid on the particle surface are not described clearly in traditional formulas. In this paper, actual random packing was built by DEM and CFD simulations were performed to investigate the factors affecting liquid holdup and wetting efficiency in trickle bed reactors, including particle shape, surface tension, contact angle, liquid viscosity, liquid density, liquid, and gas superficial velocity. Detailed fluid flow and liquid-solid interaction were described by VOF model. Four different particle shapes were investigated. It showed the particle shape has great effect and the 4-hole cylinder packing gained both highest liquid holdup and wetting efficiency. The overall simulations gave a detailed description of phase interactions and fluid flow in the voids between catalyst particles and these results could give further guidance for the design and operation of trickle bed reactors.

show abstract

Section: Introductionsupporting

confidence: 57%

Section: Contact Anglementioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Computational Investigation of Liquid Holdup and Wetting Efficiency Inside Trickle Bed Reactors with Different Catalyst Particle Shapes

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Lopes & Quinta-Ferreira 2009, 2010, wettability (e.g. Du et al 2015Du et al , 2017 and particle shape (Kang et al 2019;Deng et al 2020) on the steady-state liquid distribution. However, the effect of the aforementioned parameters on the contribution of different forces at different temporal stages of liquid spreading and their relationship with void-scale flow behaviour has not been explored.…”

Section: Introductionmentioning

confidence: 99%

Forces governing the dynamics of liquid spreading in packed beds

2022

View full text Add to dashboard Cite

Liquid spreading through a randomly packed particle-resolved bed influenced by capillary or inertial ( $AB_s \sim 1$ ), and gravitational force (moderately ( $AB_s \sim 0.1$ ) and strongly ( $AB_s \sim 0.01$ )) is investigated using the volume-of-fluid simulations. The relative contribution of governing forces at different stages of spreading is analysed using the time evolution of Weber ( $We_I$ ) and $AB_I$ numbers. We show that the dynamics of liquid spreading at $AB_s \sim 1$ is primarily governed by the inertial force in the beginning ( $AB_I > 1$ , $We_I > 1$ ) followed by the capillary force at $t/t^* \sim 1$ . This interplay of governing forces leads to inertia- and capillary-induced bubble entrapments at the void scale and promote lateral liquid spreading. When the $AB_s \sim 0.1$ , the $t/t^*$ for which the flow is governed by inertial ( $AB_I > 1$ , $We_I > 1$ ) and capillary forces ( $AB_I > 1$ , $We_I < 1$ ) decreases and the relative contribution of gravitational force is substantial at large $t/t^*$ ( $AB_I < 1$ ). This force balance leads to unified-void filling characterised by negligible bubble trapping and results in a decrease in the lateral spreading. Further decrease in the $AB_s$ to ${\sim } 0.01$ results in liquid spreading primarily governed by gravitational force ( $AB_I < 1$ ) with small contribution of inertial and capillary forces at the very beginning leading to trickling flow and a further decrease in lateral spreading. Finally, a regime map is proposed, which provides the relationship between different forces, void-scale events, and the resultant liquid spreading at $t/t^* \sim 1$ .

show abstract