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Mixing of powders, particles and/or granules obtains an economic importance in various technologies, and in the food, pharmaceutical and chemical industries. In many cases, the mixing process greatly influences the quality of the final product. The parameters of the mixing process and the design of equipment have a strong impact on the mixing efficiency, and the quality and the price of the intermediate or final product. In this study, the discrete element method (DEM) is used for modeling of granular flow in various multiple Komax and Ross mixing applications. Computational fluid dynamic (CFD) method was used for modeling of fluid flow through the Eulerian multiphase model. Coupling of these two methods provides reliable, sufficiently correct and adequate results of the proposed model compared to experimental measurements. The objective of this paper is to predict the behavior of particles in different static mixer configurations. The results of the numerical simulation are compared with appropriate experimental results. Application of this model provides the optimization of the geometry and parameters of mixing systems taking into account the quality of the mixing process and the cost of the final product. (C) 2014 Elsevier B.V. All rights reserved.

peer-reviewed, DEM/CFD (Discrete Element Method/Computational Fluid Dynamic) approach was used to develop a three dimensional model of fluid flow and mixing process of solid particles within the revolving static mixer, type Komax. Static mixers are widely used in process industry, food industry, pharmaceutical and chemical industry. Mixing process adds significant value to the final product and it can be regarded as a key process. The quality and the price of the product often depend on mixing efficiency. Both design and operation of the mixing unit itself have a strong influence on the quality produced. In this paper, DEM is used for modeling granular flow of zeolite spheres in the revolving Komax static mixer and CFD method was used for modeling fluid flow through the Eulerian multiphase model. Coupling of these two methods provides reliable analysis of particle motion and flow pattern of the working fluid. The objective of this paper is to predict the behavior of particles after several rotations of the revolving static mixer. This type of device is used for premixing action before the main mixing process, for significant reduction of mixing time and energy consumption. This type of premixing action is not investigated in detail in the open literature. The results of the numerical simulation are compared with appropriate experimental results. The special design revolving static mixer, made of transparent Plexiglas was used for this experiment. Mixing quality was examined by RSD (relative standard deviation) criterion. Application of this model provides the optimization of the number of revolutions and geometrical parameters of mixing process taking into account the quality of the mixing process., This work was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia grant TR31055.

Mixing of powders, particles and/or granules obtain an economic importance of various technologies, food industry, pharmaceutical and chemical industry. Mixing process greatly influence on quality and the price of the final product. In this study, discrete element method (DEM) is used for modeling granular flow in various multiple Komax and Ross mixing applications. The aim of this paper is to predict behavior of particles in various static mixers. The results of the numerical simulation are compared with appropriate experimental results. Quality of the mixing process is analyzed using relative standard deviation (RSD) criteria. Application of this model provide the optimization of the geometry and parameters of mixing systems taking into account the quality of the mixing process and the cost of the final product.

The mixing process greatly influence the mixing efficiency, as well as the quality and the price of the intermediate and/or the final product. Static mixer is used for premixing action before the main mixing process, for significant reduction of mixing time and energy consumption. This type of premixing action is not investigated in detail in the open literature. In this article, the novel numerical approach called Discrete Element Method is used for modelling of granular flow in multiple static mixer applications (1 - 3 Komax or Ross mixing elements were utilized), while the Computational Fluid Dynamic method was chosen for fluid flow modelling, using the Eulerian multiphase model. The main aim of this article is to predict the behaviour of granules being gravitationally transported in different mixer configuration and to choose the best configuration of the mixer taking into account the total particle path, the number of mixing elements and the quality of the obtained mixture. The results of the numerical simulations in the static mixers were compared to experimental results, the mixing quality is examined by RSD (relative standard deviation) criterion, and the effects on the mixer type and the number of mixing elements on mixing process were studied. The effects of the mixer type and the number of mixing elements on mixing process were studied using analysis of variance (ANOVA). Mathematical modelling is used for optimization of number of Ross and Komax segments in mixer in order to gain desirable mixing results. [Projekat Ministarstva nauke Republike Srbije, br. TR31055]

The mixing process greatly influence the quality of the intermediate and/or the final product, moreover, the parameters of the mixing process and the design of used equipment have a strong impact on mixing efficiency, the quality and the price of the product. In this article, Discrete Element Method is used for modeling of granular flow in multiple static mixer applications (Komax and Ross configurations were utilized). Computational Fluid Dynamic method was chosen for fluid flow modeling, using Eulerian multiphase model. Coupling of these two methods provides reliable, sufficiently correct and adequate results of proposed model compared to experimental measurements. The aim of this article is to predict the behavior of granules in different mixer configuration and to optimize parameters of the mixing process taking into account the duration of the mixing process and the quality of mixture, as well as the price of final product. Proces mešanja veoma utiče na kvalitet krajnjeg poluproizvoda i/ili krajnjeg proizvoda, a parametri procesa mešanja i dizajn opreme veoma utiču na efikasnost mešanja, kvalitet proizvoda i cenu proizvoda. U ovom radu, prikazana je upotreba metode diskretnih elemenata (engl. Discrete Element Method - DEM) na modelovanje mešanja granula u različitim konfiguracijama statičkih mešača (korišćene su različite Komax i Ross konfiguracije za mešanje). Za modelovanje protoka fluida primenjena je metoda računske dinamike fluida (engl. Computational Fluid Dynamic - CFD), korišćenjem Ojlerovog višefaznog modela. Povezivanjem rezultata ove dve metode dobija se pouzdan, dovoljno tačan i adekvatan model koji daje rezultate koji odgovaraju eksperimentalnim merenjima. Praćene su i analizirane trajektorije, brzine i ubrzanja čestica, u cilju procene kvaliteta procesa mešanja. Dobro poznati kriterijum za kvalitet mešanja, pod nazivom relativna standardna devijacija (RSD) je korišćen za ovu svrhu. Optimizacija dimenzija i parametara mešanja u statičkoj mešalici je izvedena korišćenjem matematičkog modeliranja. Cilj ovog rada je bio da se predvidi ponašanje granulamog materijala u različitim konfiguracijama mešalica i da optimizuje parametre procesa uzimajući u obzir trajanje procesa mešanja, kvalitet mešavine i cenu finalnog proizvoda mešanja. U istraživanju je primećeno da su Komax elementi primenljiviji, u poređenju sa Ross elementima, posebno kada je visina instalacije mala. Međutim, upotreba Ross je finansijski prihvatljivija, zbog njegove jednostavnije geometrije. Dodatna pregrada sa kvadratnim otvorima, koja se postavlja na izlazu iz statičke mešalice, koristi se da bi se umirilo kretanje granula na obodu cevi, kao i da smanji segregaciju granula.