Experimental detergent drying analysis in a counter-current spray dryer with swirling air flow

Wawrzyniak, P.; Jaskulski, Maciej; Piątkowski, Marcin; Sobulska, Mariia; Zbiciński, Ireneusz; Egan, Stefan

doi:10.1080/07373937.2019.1626878

Cited by 9 publications

(12 citation statements)

References 13 publications

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“…During the injection of glass beads, detergent could be seen in the powder recovered at the bottom. This is in line with the study of fouling that points out the importance of the breakage of deposit structures 12,43 and its effects on the overall solid RTD in a counter current swirl dryer under full operation. The particles can deposit in the wall an average time, in the order of 700−800 s, before being removed back into the flow.…”

Section: Analysis Of Resultssupporting

confidence: 86%

The Use of Optimized Restitution Coefficients to Improve Residence Time Prediction in Computational Fluid Dynamics-Discrete Parcel Method Models for Counter-Current Spray Dryers

Hernández

Francia

Crosby

et al. 2021

Ind. Eng. Chem. Res.

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This work studies the dispersion of solids in the cold isothermal operation of swirl counter current spray dryers. Residence time distributions (RTDs) of glass beads and detergent powder are obtained in a semi-industrial unit under varying Reynolds and injection positions and validated with the results of a novel Reynolds average Navier Stokes-discrete parcel method (DPM) framework. The simulations stress that the particle RTD is governed to a large extent by the interaction of the solids with the walls, which is usually simplified with the assumption of a particle-wall restitution coefficient. Since this is often unavailable experimentally, here, we propose an alternative combined model that integrates the computational fluid dynamics (CFD)-DPM model with reinforcement learning using a training set of experimental RTDs to extract an "effective pair of wall restitution coefficients". The method improves the accuracy of existing CFD platforms, reducing the errors in the mean residence time from 30−100% to <25%.

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Section: Analysis Of Resultssupporting

confidence: 86%

The Use of Optimized Restitution Coefficients to Improve Residence Time Prediction in Computational Fluid Dynamics-Discrete Parcel Method Models for Counter-Current Spray Dryers

Hernández

Francia

Crosby

et al. 2021

Ind. Eng. Chem. Res.

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“…In contrast, in the counter-current configuration, droplets are sprayed from the opposite side to the airflow. The relatively high slip velocities of particles result in high heat and mass transfer, and therefore, these dryers are considered to have higher throughput and thermal efficiencies than co-current spray dryers [4,5]. This configuration is primarily suitable for thermally stable materials such as detergents [5,6].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2021

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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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“…Despite being a mature technology, conventional dryers suffer from major challenges, such as large equipment size and high operational and maintenance costs. While counter-current dryers are thermally more efficient and require lesser energy input, owing to bigger temperature gradients between droplets and the air, than the co-current dryers [5,6], they are limited to thermally resistant materials such as detergents [6,7].…”

Section: Introductionmentioning

confidence: 99%

Numerical Study and Experimental Validation of Skim Milk Drying in a Process Intensified Counter Flow Spray Dryer

Rahman

Pozarlik

2021

Energies

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This research presents 3D steady-state simulations of a skim milk spray drying process in a counter-current configuration dryer. A two-phase flow involving gas and discrete phase is modeled using the Eulerian–Lagrangian model with two-way coupling between phases. The drying kinetics of skim milk is incorporated using the Reaction Engineering Approach. The model predictions are found to be in accordance with the experimental temperature measurements with a maximum average error of 5%. The validated computational model is employed further to study the effects of nozzle position, initial spray Sauter Mean Diameter (SMD), air inlet temperature, and feed rate on the temperature and moisture profiles, particle impact positions, drying histories, and product recovery at the outlet. The location of the nozzle upwards (≈23 cm) resulted in maximum product recovery and increased the mean particle residence time at the outlet. A similar trend was observed for the highest feed rate of 26 kg/h owing to the increased spray penetration upstream in the chamber. The maximum evaporation zone was detected close to the atomizer (0–10 cm) when the spray SMD is 38 µm, whereas it shifts upstream (40–50 cm) of the dryer for an SMD of 58 µm. The high air inlet temperature resulted in enhanced evaporation rates only in the initial 10–20 cm distance from the atomizer. The results obtained in this study are beneficial for the development of the novel vortex chamber-based reactors with a counter flow mechanism.

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Experimental detergent drying analysis in a counter-current spray dryer with swirling air flow

Cited by 9 publications

References 13 publications

The Use of Optimized Restitution Coefficients to Improve Residence Time Prediction in Computational Fluid Dynamics-Discrete Parcel Method Models for Counter-Current Spray Dryers

The Use of Optimized Restitution Coefficients to Improve Residence Time Prediction in Computational Fluid Dynamics-Discrete Parcel Method Models for Counter-Current Spray Dryers

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

Numerical Study and Experimental Validation of Skim Milk Drying in a Process Intensified Counter Flow Spray Dryer

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