CFD study of air flow patterns and droplet trajectories in a lab scale vortex chamber spray dryer

In order to develop an alternative spray drying technology, a high drying rate in a smaller volume must be achieved. In this paper, results of CFD study are presented, carried out to investigate the possibility of spray drying in a novel design vortex chamber. The model is validated against experimental data, that makes a good agreement with an average error of 7% with only air and 24% with water spray. Results of temperature fields and droplet impact positions are discussed. The computations demonstrate that vortex chamber spray dryer can be an attractive solution for drying technology. Keywords: CFD; spray drying; vortex chamber; atomization;

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Numerical Study toward Optimization of Spray Drying in a Novel Radial Multizone Dryer

Energies ◽

10.3390/en14051233 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1233

Author(s):

Umair Jamil Ur Rahman ◽

Artur Krzysztof Pozarlik ◽

Thomas Tourneur ◽

Axel de Broqueville ◽

Juray De Wilde ◽

...

Keyword(s):

Spray Drying ◽

Droplet Size ◽

Separation Efficiency ◽

Numerical Study ◽

Three Dimensional ◽

Droplet Size Distribution ◽

Vortex Chamber ◽

Temperature Pattern ◽

Multiphase Model ◽

Drying Technology

In this paper, an intensified spray-drying process in a novel Radial Multizone Dryer (RMD) is analyzed by means of CFD. A three-dimensional Eulerian–Lagrangian multiphase model is applied to investigate the effect of solids outlet location, relative hot/cold airflow ratio, and droplet size on heat and mass transfer characteristics, G-acceleration, residence time, and separation efficiency of the product. The results indicate that the temperature pattern in the dryer is dependent on the solids outlet location. A stable, symmetric spray behavior with maximum evaporation in the hot zone is observed when the solids outlet is placed at the periphery of the vortex chamber. The maximum product separation efficiency (85 wt %) is obtained by applying high G-acceleration (at relative hot/cold ratio of 0.75) and narrow droplet size distribution (45–70 µm). The separation of different sized particles with distinct drying times is also observed. Smaller particles (<32 µm) leave the reactor via the gas outlet, while the majority of big particles leave it via the solids outlet, thus depicting in situ particle separation. The results revealed the feasibility and benefits of a multizone drying operation and that the RMD can be an attractive solution for spray drying technology.

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Energetic Analysis in a Spray Drying Process

Journal of Advanced Thermal Science Research ◽

10.15377/2409-5826.2020.07.5 ◽

2020 ◽

Vol 7 ◽

pp. 40-47

Author(s):

Alex Notaroberto Madeira ◽

Carlos Alberto Chaves ◽

Wendell de Queiróz Lamas

Keyword(s):

Spray Drying ◽

Water Mass ◽

Spray Dryer ◽

Water Spray ◽

Drying Process ◽

Power Sources ◽

Atmospheric Air ◽

Energetic Analysis

The present work aims in evaluate the installation of an equipment of spray drying, by psychrometry technique, analyse the power sources consumption and relates with the productivity of the equipment, by energy auditory. This work consists in comparing the evaporation capacity of a 750 kg/h of water spray dryer and the amount of water that comes from atmospheric air, where the equipment consumes 160 kWh and 80 kg of LGP/h. Therefore, this work demonstrates that to project a spray dryer it must be analysed these water mass values in atmospheric air and be contemplated a dehumidifier in order to prevent so significant and different losses in different periods of the same day.

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Which Is the Motion State of a Droplet on an Inclined Hydrophilic Rough Surface in Gravity: Pinned or Sliding?

Applied Sciences ◽

10.3390/app11093734 ◽

2021 ◽

Vol 11 (9) ◽

pp. 3734

Author(s):

Jian Dong ◽

Youhai Guo ◽

Long Jiao ◽

Chao Si ◽

Yinbo Bian ◽

...

Keyword(s):

Rough Surface ◽

Contact Angle Hysteresis ◽

Minimum Energy ◽

Contact Angles ◽

Microfluidic Chips ◽

Motion State ◽

Receding Contact ◽

Novel Design ◽

Minimum Energy Dissipation ◽

Good Agreement

The motion state of a droplet on an inclined, hydrophilic rough surface in gravity, pinned or sliding, is governed by the balance between the driving and the pinned forces. It can be judged by the droplet’s shape on the inclined hydrophilic rough surface and the droplet’s contact angle hysteresis. In this paper, we used the minimum energy theory, the minimum energy dissipation theory, and the nonlinear numerical optimization algorithm to establish Models 1–3 to calculate out the advancing/receding contact angles (θa/θr), the initial front/rear contact angles (θ1−0/θ2−0) and the dynamic front/rear contact angles (θ1−*/θ2−*) for a droplet on a rough surface. Also, we predicted the motion state of the droplet on an inclined hydrophilic rough surface in gravity by comparing θ1−0(θ2−0) and θ1−*(θ2−*) with θa(θr). Experiments were done to verify the predictions. They showed that the predictions were in good agreement with the experimental results. These models are promising as novel design approaches of hydrophilic functional rough surfaces, which are frequently applied to manipulate droplets in microfluidic chips.

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Analysis of a Loss of Feedwater Case at the Ringhals-3 NPP Using RELAP5/PARCS Coupled Codes

Volume 3: Thermal Hydraulics; Instrumentation and Controls ◽

10.1115/icone16-48116 ◽

2008 ◽

Author(s):

Jo´zsef Ba´na´ti ◽

Mathias Sta˚lek ◽

Christophe Demazie`re ◽

Magnus Holmgren

Keyword(s):

Temperature Fields ◽

Pressurized Water Reactor ◽

Pressurized Water ◽

History Effects ◽

Coupled Codes ◽

Fuel Assemblies ◽

Development And Validation ◽

Secondary Side ◽

Relap5 Code ◽

Good Agreement

This paper deals with the development and validation of a coupled RELAP5/PARCS model of the Swedish Ringhals-3 pressurized water reactor against a Loss of Feedwater transient, which occurred on August 16, 2005. At first, the stand-alone RELAP5 and PARCS models are presented. All the 157 fuel assemblies are modeled in individually in both codes. The model is furthermore able to handle possible asymmetrical conditions of the flow velocity and temperature fields between the loops. On the neutronic side, the dependence of the material constants on history effects, burnup, and instantaneous conditions is accounted for, and the full heterogeneity of the core is thus taken into account. The reflectors are also explicitly represented. The coupling between the two codes is touched upon, with emphasis on the mapping between the hydrodynamic/heat structures and the neutronic nodes. The transient was initiated by a malfunction of the feedwater valve at the 2nd steam generator. Consequently, the turbines were tripped and, because of the low level in the SG-2 the reactor was scrammed. Activation of the auxiliary feedwater provided proper amount of cooling from the secondary side, resulting in safe shutdown conditions. Capabilities of the RELAP5 code were more challenged in this transient, where the influences of the feedback from the neutron kinetic side were also taken into account in the analysis. The calculated values of the parameters show good agreement with the measured data.

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Spray-Drying Technology

Formulating Poorly Water Soluble Drugs - AAPS Advances in the Pharmaceutical Sciences Series ◽

10.1007/978-3-319-42609-9_10 ◽

2016 ◽

pp. 437-525 ◽

Cited By ~ 2

Author(s):

Dave A. Miller ◽

Daniel Ellenberger ◽

Marco Gil

Keyword(s):

Spray Drying ◽

Drying Technology

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Spray Drying of Serratia marcescens in the Jet Spray Dryer

Industrial & Engineering Chemistry Fundamentals ◽

10.1021/i160061a005 ◽

1977 ◽

Vol 16 (1) ◽

pp. 12-18 ◽

Cited By ~ 3

Author(s):

E. W. Comings ◽

Harry Higa ◽

J. E. Myers ◽

Henry Koffler ◽

H. A. McLain

Keyword(s):

Serratia Marcescens ◽

Spray Drying ◽

Spray Dryer

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Spray Drying Performance of a Laboratory Spray Dryer for Tomato Powder Preparation

Drying Technology ◽

10.1081/drt-120023180 ◽

2003 ◽

Vol 21 (7) ◽

pp. 1273-1289 ◽

Cited By ~ 28

Author(s):

Athanasia M. Goula ◽

Konstantinos G. Adamopoulos

Keyword(s):

Spray Drying ◽

Spray Dryer ◽

Powder Preparation ◽

Tomato Powder

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Effect of Spray Dryer Scale Size on the Properties of Dried Beetroot Juice

Molecules ◽

10.3390/molecules26216700 ◽

2021 ◽

Vol 26 (21) ◽

pp. 6700

Author(s):

Jolanta Gawałek

Keyword(s):

Spray Drying ◽

Industrial Process ◽

Laboratory Scale ◽

Industrial Scale ◽

Process Conditions ◽

Spray Dryer ◽

Beetroot Juice ◽

Centrifugal Atomization ◽

Drying Conditions ◽

Drying Efficiency

Experiments detailing the spray drying of fruit and vegetable juices are necessary at the experimental scale in order to determine the optimum drying conditions and to select the most appropriate carriers and solution formulations for drying on the industrial scale. In this study, the spray-drying process of beetroot juice concentrate on a maltodextrin carrier was analyzed at different dryer scales: mini-laboratory (ML), semi-technical (ST), small industrial (SI), and large industrial (LI). Selected physicochemical properties of the beetroot powders that were obtained (size and microstructure of the powder particles, loose and tapped bulk density, powder flowability, moisture, water activity, violet betalain, and polyphenol content) and their drying efficiencies were determined. Spray drying with the same process parameters but at a larger scale makes it possible to obtain beetroot powders with a larger particle size, better flowability, a color that is more shifted towards red and blue, and a higher retention of violet betalain pigments and polyphenols. As the size of the spray dryer increases, the efficiency of the process expressed in powder yield also increases. To obtain a drying efficiency >90% on an industrial scale, process conditions should be selected to obtain an efficiency of a min. of 50% at the laboratory scale or 80% at the semi-technical scale. Designing the industrial process for spray dryers with a centrifugal atomization system is definitely more effective at the semi-technical scale with the same atomization system than it is at laboratory scale with a two-fluid nozzle.

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