Modeling, simulation and stabilizing H∞-control of an oscillating continuous crystallizer with fines dissolution

Motz, S.; Mitrović, Aleksandra; Gilles, E. D.; Vollmer, Ulrich; Raisch, Jörg

doi:10.1016/s0009-2509(03)00199-4

Cited by 15 publications

(4 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Processes for continuous particle formation often show highly dynamic behavior: continuous crystallization processes with classifying product removal are one example in a solid/liquid environment (Lei et al, 1971;Motz et al, 2003;Vollmer and Raisch, 2002). There, small crystals are dissolved and re-fed as supersaturated solution to increase the size of the product crystals.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation of process stability of continuous spray fluidized bed layering with external product separation

Schmidt

Rieck

Bück

et al. 2015

Chemical Engineering Science

View full text Add to dashboard Cite

Experimental investigation of dynamics in continuous layering with external classification. Proof of oscillations in particle size distribution (stable limit cycle). Similar periodic behavior for significant variation in mean diameter of milled particles. Milling behavior determined as key process influence. a b s t r a c tThe present work investigates experimentally continuous spray fluidized bed layering with external product separation. In this process configuration, growing particles are continuously withdrawn and classified externally by two sieves into product fraction, undersize and oversize fraction. The oversize fraction is milled and fed back to the fluidized bed alongside with the undersized fraction. New seed particles for the layering process are provided by recycling of milled particles and agglomeration of dust particles, formed by dried droplets (overspray) and attrition. Until now, this process configuration has been investigated by simulations only. For certain parameter regimes, these models predict oscillations of the particle size distribution. Based on these predictions, even theoretical controllers have already been developed to diminish these oscillations. An experimental investigation of these oscillations of the particle size has not yet been published. Our work presents a systematic study of the process and proves the existence of oscillations of the particle size distribution in the fluidized bed.

show abstract

Section: Introductionmentioning

confidence: 99%

Experimental investigation of process stability of continuous spray fluidized bed layering with external product separation

Schmidt

Rieck

Bück

et al. 2015

Chemical Engineering Science

View full text Add to dashboard Cite

show abstract

“…In order to control a particulate process with regard to size distribution, model-based techniques have been developed [6][7][8]. Also for the quantitative understanding of crystallization processes a sufficiently detailed model is required [9].…”

Section: Introductionmentioning

confidence: 99%

Crystal Aggregation in a Flow Tube: Image‐Based Observation

Borchert

Sundmacher

2011

Chem Eng & Technol

View full text Add to dashboard Cite

The aggregation of crystals within a flow tube was observed based on data extracted from images of the bypassing population. The experiments were conducted under different conditions, namely the flow rate and the particle concentration have been varied simultaneously and two different solvents were used in which the aggregation extent was found to be different under otherwise constant conditions. The analysis of images of bypassing crystals allows for the acquisition of rich datasets both in terms of the variety of shape descriptors and number of particles. This amount of data enables the determination of at least bivariate number distributions of high accuracy with simple histograms. The interpretation of the data is further improved with kernel histograms with which also higher-dimensional volume distributions can be obtained in good quality based on relatively few data points. Indeed, the isosurfaces of 3D distributions turned out to be helpful for inspection of the acquired data.

show abstract

“…Eek, Pouw, and Bosgra (1995) investigate the use of proportional-only feedback control. Vollmer and Raisch (2002) and Motz, Mitrović, Gilles, Vollmer, and Raisch (2003) consider H ∞ control. Christofides and coworkers (Chiu & Christofides, 1999;Chiu & Christofides, 2000;El-Farra, Chiu, & Christofides, 2001;Shi, El-Farra, Li, Mhaskar, & Christofides, 2006) have applied a variety of advanced control methodologies to crystallization processes, including robust nonlinear control and predictive control.…”

Section: Introductionmentioning

confidence: 99%