Mathematical modelling of spray drying

Zbiciński, Ireneusz; Grabowski, S; Strumiłło, Czesław; Király, László; Krzanowski, W. J.

doi:10.1016/0098-1354(88)85029-4

Cited by 17 publications

(11 citation statements)

References 6 publications

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“…It is usually considered that hot gas and droplets are moving in parallel within the drying chambers [70]. This simulation approach is widely used to model product characteristics during spray drying where tall-form spray dryers were used [72,109,110,112]. A major advantage of the 1-D approach is the capability to evaluate the "average" behavior (temperature, moisture concentration and velocity profiles) of the powder and hot gas following drying time or dryer height integration.…”

Section: "1-d" (Finer-scale) Simulation Approachmentioning

confidence: 99%

“…Drying processes are simulated using overall heat and mass balance equations to predict gas temperature, gas humidity and product moisture content at the inlet or outlet of dryers [10]. Drying chambers are mostly treated as well-mixed reactors [30,95,110]. Calculations for heat and mass balances over spay dryers and fluidized-bed dryers are usually done separately.…”

Section: Simulation Of Spray Dryingmentioning

confidence: 99%

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One-dimensional simulation of co-current, dairy spray drying systems – pros and cons

Patel

Chen

Jeantet

et al. 2010

Dairy Sci. Technol.

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-One-dimensional (1-D) simulation is a useful technique for the evaluation of dryer operating parameters and product properties before conducting real spray drying trials. The main advantage of a 1-D simulation tool is its ability to perform fast calculations with significant simplicity. Mathematical models can be formulated using heat, mass and momentum balances at the droplet level to estimate time-dependent gas and droplet parameters. One of the purposes of this paper is to summarize key mathematical models that may be used to perform 1-D simulation for spray drying processes, predict essential product-drying gas parameters, assess the accuracy of prediction using pilot-scale spray drying data and perhaps most importantly address the main benefits and limitations of the 1-D simulation technique in relation to industrial spray drying operations. The results of a recent international collaborative study on the development of spray drying process optimization software for skim milk manufacture are presented as an example of the application of 1-D simulation in milk processing.spray drying / one-dimensional simulation / modeling / drying kinetics / dairy product / droplet drying Article published by EDP Sciences à l'échelle de la gouttelette pour estimer les paramètres de vapeur et de gouttelette qui varient au cours du temps. Un des objectifs de cet article est de présenter de façon synthétique les modèles mathé-matiques clés qui peuvent être utilisés pour réaliser une simulation 1-D, prédire les paramètres de vapeur essentiels pour le séchage du produit, évaluer la précision de la prédiction en utilisant les données du séchage par atomisation obtenues à l'échelle pilote, et enfin d'aborder les principaux bénéfices et limites de la technique de simulation 1-D en relation avec les opérations de séchage par atomisation industrielles. Les résultats d'une récente étude réalisée en collaboration internationale sur le développement d'un logiciel d'optimisation du procédé de séchage par atomisation pour la production de poudre de lait écrémé sont présentés pour illustrer l'application de la simulation 1-D.séchage par atomisation / simulation mono-dimensionnelle / modélisation / cinétique de séchage / produit laitier / séchage d'une gouttelette

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Section: "1-d" (Finer-scale) Simulation Approachmentioning

confidence: 99%

Section: Simulation Of Spray Dryingmentioning

confidence: 99%

One-dimensional simulation of co-current, dairy spray drying systems – pros and cons

Patel

Chen

Jeantet

et al. 2010

Dairy Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…In all models in this group, the parameters of the drying agent in a cross-sectional area of the dryer are taken as constant. Zbicinski et al reported that results obtained in this group of models describe well the process of spray drying [11]. However, the application of overall heat and mass balance equations makes it impossible to determine local distributions of particular parameters for flue gas during spray drying.…”

Section: Introductionmentioning

confidence: 93%

“…Furthermore, the method of gas-liquid contacting in the spray dryer must be taken into consideration. Taking as a basis the character of equations describing the process of spray drying in mathematical models presented in the literature [11], a classification of these models may be given.…”

Section: Introductionmentioning

confidence: 99%

“…Such models are solved only for one particle diameter and it is assumed that the particle temperature is the temperature of adiabatic saturation during the whole drying process [11]. Models of this group allow the basic parameters of flue gas during drying Nomenclature A area (m 2 ) C Na 2 CO 3 conversion efficiency of trona C p heat capacity (J/(kg K)) C SO 2 SO 2 concentration (kmol/m 3 ) C T total gas concentration (kmol/m 3 …”

Section: Introductionmentioning

confidence: 99%

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Modelling of trona based spray dry scrubbing of SO2

Aydın¹,

Nasün-Saygılı²

2007

Chemical Engineering Journal

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Surface‐center temperature differences within milk droplets during convective drying and drying‐based Biot number analysis

Patel¹,

Chen²

2008

AIChE Journal

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in Wiley InterScience (www.interscience.wiley.com).An assumption of uniform temperature is frequently used when evaluating average temperature-time and average moisture content-time profiles for the convective drying of small droplets or thin-layer materials. In most studies, the assumption of uniform temperature was justified by estimating the heat-transfer Biot number at the beginning and end of the drying process. However, the conventional Biot number analysis performed in the literature does not reflect the evaporative effect. In this article, we have examined the temperature uniformity and the heat-transfer Biot number during the drying of skim milk droplets under laboratory drying conditions following the entire drying process. Surface-centre temperature differences and conventional and drying-based Biot numbers are calculated during the drying of skim milk droplets. A simple procedure is outlined to estimate the extent of temperature nonuniformity within the droplet. Results demonstrated that temperature nonuniformity within the skim milk droplets under drying conditions examined is very small, thus the uniform temperature assumption is more likely to be a reliable approach to model heat and mass transfer processes in industrial spray dryers. The analyses provided in this study help in understanding a few assumptions used in literature, and offer a framework that may be used in the future. 2008 American Institute of Chemical Engineers AIChE J, 54: 3273-3290, 2008 Keywords: biot number, spray drying, droplet drying, modeling, temperature distribution IntroductionSpray drying is a widely used industrial operation that involves evaporation of moisture from droplets until the desired particle moisture content is achieved. A mathematical analysis to characterize the drying of individual droplets is important because it provides a more intelligent and robust control over the product quality and the plant operation. A simple approach to achieve the expected product quality during spray drying can be formulated by recognizing what the droplet/particle experiences during its transit in the drying chamber.1 The physical and biochemical properties of the final dried product are directly influenced by the droplet's temperature and moisture content history within the dryer. Hence, predicting the droplet's temperature-time and moisture concentration-time profiles following the entire drying operation is crucial for manufacturing the best-quality product and optimizing the operation. During spray drying, the evaporation from droplets is facilitated by mixing hot drying gas with a spray of small droplets. Droplets receive the heat from drying gas, and subsequently moisture is transferred from the droplets to the bulk gas in the form of vapor. The driving force for these heat and mass transfer processes may be the liquid moisture concentration difference, the vapor pressure difference, or the temperature difference within and outside the droplet. The transport of heat and moisture may lead to nonuniformity of temperatu...

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Mathematical modelling of spray drying

Cited by 17 publications

References 6 publications

One-dimensional simulation of co-current, dairy spray drying systems – pros and cons

One-dimensional simulation of co-current, dairy spray drying systems – pros and cons

Modelling of trona based spray dry scrubbing of SO2

Surface‐center temperature differences within milk droplets during convective drying and drying‐based Biot number analysis

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