کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
237060 465694 2012 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Particle size distribution reconstruction: The moment surface method
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Particle size distribution reconstruction: The moment surface method
چکیده انگلیسی

Numerical simulation of typical chemical engineering processes, such as crystallisation, liquid–liquid extraction, milling and other multi-phase operations in which exist discrete and continuous phases is highly computationally intensive problems. For this reason numerical techniques, such as the Method of Moments (MOM) and Quadrature Method of Moments (QMOM), are utilised to improve the computational efficiency of these simulations. The downside to these approaches is that the simulations only produce the moments of the Particle Size Distribution (PSD), with the actual distribution not preserved. Knowledge of the PSD is very important for many industrial unit operations, particularly in dynamic multi-phase flows in chemical engineering where the composition of the discrete phase(s) evolves in time or space. For example, control of the PSD in crystallisation operations may be required to ensure more efficient downstream operations such as filtration and clarification. Several methods for the reconstruction of a distribution from its respective moments are available in the literature. Typically these techniques are quite computationally expensive. The novel technique presented in this paper involves the pre-calculation of the moments of a pre-defined 2-parameter Probability Density Function (PDF) for a range of values of each parameter. This pre-calculation results in moment surfaces where the surfaces are a function of the two defining parameters. The intersection of constant moment contour lines (termed moment iso-lines) on these surfaces using simulation moment outputs results in the recovery of the defining parameters. Knowledge of the PDF and the total particle count or solids loading allows for the reconstruction of the full PSD. This technique proves to be very efficient which makes it ideal for the reconstruction of large numbers of distributions, for example in transient population balance models or model-based control algorithms, without the need for repeated application of optimisation algorithms.

Third moment, m3, for the Weibull distribution.Figure optionsDownload as PowerPoint slideHighlights
► Reconstruction of PSDs from moments methods is a currently unsolved inverse problem.
► Presented is a reconstruction method requiring only two moments of the PSD.
► Assumes the predefinition of the PSD’s functional form.
► Very efficient method which avoids the use of optimisation algorithms.
► Suited to simulations requiring large numbers of reconstructions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Powder Technology - Volume 222, May 2012, Pages 8–14
نویسندگان
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