Solution of inverse problems in population balances-II. Particle break-up

Sathyagal, Arun; Ramkrishna, Doraiswami; Narsimhan, Ganesan

doi:10.1016/0098-1354(94)00062-s

Cited by 49 publications

(72 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the past, there have been numerous experimental studies to determine the drop's breakup frequency. For example, many attempts have been made to determine this frequency in stirred tanks, or in turbulent pipe flows, by measuring the time evolution of the drop-size p.d.f.s (Sathyagal, Ramkrishna & Narsimhan 1994;Sathyagal & Ramkrishna 1996;Narsimhan, Gupta & Ramkrishna 1979;Narsimhan, Nejfelt & Ramkrishna 1984;Nambiar et al 1992Nambiar et al , 1994; and others). As mentioned above, the difficulty in the use of stirred vessels is that the turbulence in the vessel is not very well characterized since it is not only inhomogeneous throughout the vessel, but more importantly, it is highly anisotropic consisting of high-shear regions on the surface of the impeller and strong tip vórtices shed by the impeller blades.…”

Section: Introductionmentioning

confidence: 99%

On the breakup of an air bubble injected into a fully developed turbulent flow. Part 1. Breakup frequency

1999

View full text Add to dashboard Cite

The transient evolution of the bubble-size probability density functions resulting from the breakup of an air bubble injected into a fully developed turbulent water flow has been measured experimentally using phase Doppler particle sizing (PDPA) and image processing techniques. These measurements were used to determine the breakup frequency of the bubbles as a function of their size and of the critical diameter

show abstract

Section: Introductionmentioning

confidence: 99%

On the breakup of an air bubble injected into a fully developed turbulent flow. Part 1. Breakup frequency

1999

View full text Add to dashboard Cite

show abstract

“…The development of models to describe the daughter drop distribution function is intrinsically challenging because of its dependence on both the parent and daughter drop volumes. Various coarse-grain models have been formulated based on a simplified picture of the drop breakup microphysics [Vankova et al, 2007;Raikar et al, 2007], and various procedures have been proposed for solving the inverse problem of deriving the daughter drop distribution from experimental data [Kostoglou and Karabelas, 2005;Raikar et al, 2006, Sathyagal et al,1995. However, the coarse-grain models are inevitably over-simplified and ad hoc assumptions are required to regularize the otherwise, ill-posed inverse problem.…”

Section: Introductionmentioning

confidence: 99%

Multiscale models of nuclear waste reprocessing : from the mesoscale to the plant-scale.

Rao¹,

Brotherton²,

Domino³

et al. 2012

View full text Add to dashboard Cite

Nuclear waste reprocessing and nonproliferation models are needed to support the renaissance in nuclear energy. This report summarizes an LDRD project to develop predictive capabilities to aid the next-generation nuclear fuel reprocessing, in SIERRA Mechanics, Sandia's high performance computing multiphysics code suite and Cantera, an open source software product for thermodynamics and kinetic modeling.Much of the focus of the project has been to develop a moving conformal decomposition finite element method (CDFEM) method applicable to mass transport at the water/oil droplet interface that occurs in the turbulent emulsion of droplets within the contactor. Contactor-scale models were developed using SIERRA Mechanics turbulence modeling capability. Unit operations occur at the column-scale where many contactors are connected in series. Population balance models 4 were developed to investigate placements and coupling of contactors at this scale. Thermodynamics models of the separation were developed in Cantera to allow for the prediction of distribution coefficients for various concentrations of surfactant and acid. Droplet-scale modeling was conducted in a microfluidic device and for verification of the algorithm. Extensive validation and discovery experiments were performed at the droplet and contactor-scales for both fluid dynamics and mass transport. 5 AcknowledgmentsThe authors would like to thank our mission specialist Veena Tikare for helping us develop the project, our reprocessing material balance expert Ben Cipiti for explaining the details of the reprocessing plant., Roger Pawlowski and Rich Schiek helped with the idea of a scalable network model, but were unable to continue with the project, though were very helpful in the first year of the work. We believe this type of work should be continued at Sandia. Paul Galambos and John Pflug supported our microfluidic experiments. Reviewers Randy Schunk and Lisa Mondy provided helpful feedback. Randy Schunk also helped with our droplet-scale modeling in a moving reference frame. The Aria Product Owners past and present, Amalia Black, Sheldon Tieszen, and Kim Mish, have been invaluable for keeping the project going despite the many other directions of Sierra Mechanics. We would like to thank the "Enabling Predictive Simulations" investment area of the LDRD program for funding this work. We would like to express our gratitude to the LDRD office for the extension given for receiving the final report due to the illness of the PI.6

show abstract

“…Determination of the collision frequency function is a complex task in most of the models 6 and it is very difficult to determine it from experimental data. However, an alternative way of retrieving the 7 kernels based on experimental data is to solve the inverse problem [51,52]. Braumann and Kraft studied the 8 inverse problem occurring in a multidimensional population balance model describing granulation employing 9 linear response surfaces [39] and second order response surfaces [53].…”

mentioning

confidence: 99%

“…Therefore, experiments have to be carried out in 12 order to identify and measure the unknown model parameters, e.g. aggregation rate constants [51][52][53]73]. …”

mentioning

confidence: 99%

Model-based analysis of high shear wet granulation from batch to continuous processes in pharmaceutical production – A critical review

Kumar

Gernaey

Beer

et al. 2013

European Journal of Pharmaceutics and Biopharmaceutics

109

View full text Add to dashboard Cite

The manufacturing of pharmaceutical dosage forms, which has traditionally been a batch-wise process, is now also transformed into a series of continuous operations. Some operations such as tabletting and milling are already performed in continuous mode, while the adaptation towards a complete continuous production line is still hampered by complex steps such as granulation and drying which are considered to be too inflexible to handle potential product change-overs. Granulation is necessary in order to achieve good flowability properties and better control of drug content uniformity. This paper reviews modelling and supporting measurement tools for the high shear wet granulation (HSWG) process, which is an important granulation technique due to the inherent benefits and the suitability of this unit operation for the desired switch to continuous mode. For gaining improved insight of the complete system, particle-level mechanisms are required to be better understood, and linked with an appropriate meso-or macro-scale model. A brief review has been provided to understand the mechanisms of the granulation process at micro or particle-level such as those involving wetting and nucleation, aggregation, breakage and consolidation. Further, population balance modelling (PBM) and the discrete element method (DEM), which are the current state-of-the-art methods for granulation modelling at micro-to meso-scale, are discussed. The DEM approach has a major role to play in future research as it bridges the gap between micro-and meso-scales. Furthermore, interesting developments in the measurement technologies are discussed with a focus towards inline measurements of the granulation process to obtain experimental data which are required for developing good models. Based on the current state of the developments, the review focuses on the twin screw granulator as a device for * Email address: ingmar.nopens@ugent.be, Tel.: +32 (0)9 264 61 96; fax: +32 (0) continuous HSWG and attempts to critically evaluate the current process. As a result, a set of open research questions are identified. These questions need to be answered in the future in order to fill the knowledge gap that currently exists both at micro-and macro-scale, and which is currently limiting the further development of the process to its full potential in pharmaceutical applications.

show abstract

Solution of inverse problems in population balances-II. Particle break-up

Cited by 49 publications

References 14 publications

On the breakup of an air bubble injected into a fully developed turbulent flow. Part 1. Breakup frequency

On the breakup of an air bubble injected into a fully developed turbulent flow. Part 1. Breakup frequency

Multiscale models of nuclear waste reprocessing : from the mesoscale to the plant-scale.

Model-based analysis of high shear wet granulation from batch to continuous processes in pharmaceutical production – A critical review

Contact Info

Product

Resources

About