Analysis of dust distribution in silo during axial filling using computational fluid dynamics: Assessment on dust explosion likelihood

Rani, Siti Ilyani; Aziz, Badhrulhisham Abdul; Gimbun, Jolius

doi:10.1016/j.psep.2015.04.003

Cited by 27 publications

(9 citation statements)

References 24 publications

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“…This finding is consistent with (Wypych et al 2005) and (Wang et al 2016) who identified a high recirculating region near a falling particle stream which accelerates the migrations of fines into the surrounding air. The upward moving air near the silo wall gradually reduces its velocity with entrained particles gradually settling to the bottom (Rani et al 2015). These settling particles are continuously charged by fresh fines from the main falling stream.…”

Section: Dust Concentration Measurements Using Optical Methodsmentioning

confidence: 99%

“…This The obtained dust concentration distribution in the experimental silo was then compared with CFD results by (Rani et al 2015). Since the materials used were different and the silos had …”

Section: Dust Concentration Measurements Using Optical Methodsmentioning

confidence: 99%

“…The prevention of dust explosions in industrial silos can be achieved by minimising/ eliminating the formation of dust clouds that exceed the lower explosion limit (LEL) (Rani et al 2015). The formation of dust clouds can be suppressed by installing an "Anti-segregation tube (AST)" (Dyrøy et al 2001) into the biomass storage silo.…”

Section: Dust Concentration Measurements Using Optical Methodsmentioning

confidence: 99%

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Predicting concentrations of fine particles in enclosed vessels using a camera based system and CFD simulations

Waduge

Zigan

Stone

et al. 2017

Process Safety and Environmental Protection

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-Trinanes, P. (2017). Predicting concentrations of fine particles in enclosed vessels using a camera based system and CFD simulations. Process Safety and Environmental Protection, Predicting concentrations of fine particles in enclosed vessels using a camera based system and CFD simulations AbstractOne of the main challenges in industries handling biomass is the consequence of the particle breakage of pelletised biomass in smaller fractions which can lead to fine particles smaller 500 ¿m that can form dust clouds in the handling and storing equipment. These dust clouds present potential health and safety hazards as well as dust explosion hazards to plant operators because the airborne dust can occur in high concentrations close to the dust explosion limits of the biomass material, during the filling process of storage silos. Preventing dust explosions and the damage of plant infrastructures requires a profound understanding of the particle/air dynamics in the dust cloud circulating in the storage silo. The limited access to the storage facilities as well as the silo size requires a detailed study of the particle/air dynamics at different scales. Lab scale experiments were conducted as a first step to establishing a new optical method for measuring particle concentrations. A small scale experimental rig was fed centrally with different sized wood pellets and a single camera and a laser was utilised to capture the dust concentration in different areas of the silo. According to the experimental results, a higher mass concentration of dust was observed near the silo wall as well as near the main particle jet. However, the mass concentrations were below the explosive limits at the area in between main particle jet and silo wall. These experimental results were then feeding into a 2D CFD simulation representing the particle dynamics in the laser sheet (2D plane). Qualitative findings show a good agreement of the particle/air dynamics between experiments and simulations. AbstractBiomass generates a increasing interest as renewable fuel and industries handling biomass show fast levels of growths over the last decade and, yet, several challenges remain in the handling, transporting and storing of biomass such as wood pellets. One challenge is the consequence of the particle breakage of pelletised biomass in smaller fractions which can lead to fine particles smaller 500 microns which can form dust clouds in the handling and storing equipment. These dust clouds present potential health and safety hazards as well as dust explosion hazards to plant operators because during the filling process of storage silos the airborne dust can occur in high concentrations close to the dust explosion limits of the 2 biomass material. Preventing dust explosions and the damage of plant infrastructures requires a profound understanding of the particle/ air dynamics in the dust cloud circulating in the storage silo. The limited access to the storage facilities as well as the silo size require a detailed study of the particle/ air dynamics a...

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Section: Dust Concentration Measurements Using Optical Methodsmentioning

confidence: 99%

Section: Dust Concentration Measurements Using Optical Methodsmentioning

confidence: 99%

Section: Dust Concentration Measurements Using Optical Methodsmentioning

confidence: 99%

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Predicting concentrations of fine particles in enclosed vessels using a camera based system and CFD simulations

Waduge

Zigan

Stone

et al. 2017

Process Safety and Environmental Protection

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“…In fact, the numerous theoretical and experimental studies on electric arcs generally deal with electrode phenomena in order to improve the performance of the electron emission of the cathode and its resistance to erosion. [18][19][20] This paper presents a global characterization of a spark discharge with controlled energy, which is generally used to ignite the combustion of metallic powders in a modified Hartmann tube [9] between two ceriated tungsten electrodes (Section 2.3). In addition, the spatio-temporal distribution of the plasma discharge parameters such as temperature and electron density is poorly known over a wide current density range.…”

Section: Introductionmentioning

confidence: 99%

Characterization of a spark discharge for dust cloud ignition

Sankhe

Bernard

Wartel

et al. 2018

Contributions to Plasma Physics

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Spark discharges are widely used to ignite flammable gases, liquids, or dust. For a better understanding of the interaction between the spark discharge and the ignited media (gas, liquid, or dust), it is necessary to measure some key parameters of the spark, especially the space-time variation of its temperature. Determination of temperature gradients would allow a more precise and realistic simulation of the ignition process. In fact, electrons and particles in the discharge zone get their energy with increasing temperature before interacting with particles of the media to ignite the flame. In this study, optical emission spectroscopy of the spark discharge between two tungsten electrodes was performed. Assuming excitation balance between the WI lines, a Boltzmann plot after an Abel inversion gives the excitation temperature and its space-time variation. For a 100-s time discharge, at 80-s delay, we measured 7,000 K at the centre of the column zone, 4,100 K at the centre of the cathode zone, and 3,600 K at the centre of the anode zone. Assuming a singly ionized tungsten plasma and excitation equilibrium, we used also the Saha-Boltzmann equation to calculate the plasma composition. The electron density at the column zone was about 3 × 10 17 cm −3 , which is two orders of magnitude higher than in the rest of the spark.

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“…However, previous research has been limited to transfer stations [5] and underground mining [6][7][8] which used intrusive sampling methods such as dust monitors and collection trays similar to that used by Stone et al [9]. Researchers, such as Rani et al [10] have used numerical simulation (CFD) to predict dust concentration levels in cylindrical storage silos. This study investigated the dust distribution near the central filling stream during silo filling and identified areas of high concentrations close to the explosion limit of the given material.…”

mentioning

confidence: 99%

A Modelling and Validation Approach for Predicting Particle Concentrations of Airborne Dust during the Filling Process of Cylindrical Silos

et al. 2021

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Traditionally, when undertaking feasibility studies for designing new storage facilities such as storage silos, engineers will extract design information from experiments and evaluate potential risks associated with health and safety, suitability design for reliable material flow, and quality of products. The simulation approach applied incorporates Computational Fluid Dynamics (CFD), and Discrete Element Modelling (DEM) approaches and experimental tests will be used for validating these simulation results. One important aspect related to handling fine and dusty materials (particles smaller than 100 microns) is the associated risk of dust explosions, which needs to be evaluated before the commissioning of storage silos; to evaluate the accumulation of fines during the silo filling process, simulations and experiments were conducted. Alumina and salt were used here as reference materials for calibration and the validation purposes. The validation efforts are significant due to the fact that the data that is accessible in simulations is vastly different to the accessible data in experiments, which is restricted by measurement techniques and equipment. Such restrictions are observed in the evaluation of particle concentrations in a large confined volume. A new methodology has been developed to evaluate concentrations in both simulations and experiments by employing a non-dimensional factor [k], here called “Concentration Rank Factor” (CRF). A significant finding of this research is that experiments and simulations can be compared using CRF. It has been found to be within 2% of the experiment averaged value of 0.64.

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Analysis of dust distribution in silo during axial filling using computational fluid dynamics: Assessment on dust explosion likelihood

Cited by 27 publications

References 24 publications

Predicting concentrations of fine particles in enclosed vessels using a camera based system and CFD simulations

Predicting concentrations of fine particles in enclosed vessels using a camera based system and CFD simulations

Characterization of a spark discharge for dust cloud ignition

A Modelling and Validation Approach for Predicting Particle Concentrations of Airborne Dust during the Filling Process of Cylindrical Silos

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