The effect of rotational speed on granular flow in a vertical bladed mixer
Identifikátory výsledku
Kód výsledku v IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F44555601%3A13440%2F15%3A43886673" target="_blank" >RIV/44555601:13440/15:43886673 - isvavai.cz</a>
Nalezeny alternativní kódy
RIV/67985858:_____/15:00451672 RIV/60461373:22340/15:43899859
Výsledek na webu
<a href="http://dx.doi.org/10.1016/j.powtec.2015.04.035" target="_blank" >http://dx.doi.org/10.1016/j.powtec.2015.04.035</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.powtec.2015.04.035" target="_blank" >10.1016/j.powtec.2015.04.035</a>
Alternativní jazyky
Jazyk výsledku
angličtina
Název v původním jazyce
The effect of rotational speed on granular flow in a vertical bladed mixer
Popis výsledku v původním jazyce
Granular mixing is an important unit operation used to ensure the uniformity of mixture properties. Unfortunately, the mechanisms of particles' motion and the role of operation parameters remain poorly understood. In this work, granular mixing is studied using computer simulations via DEM (discrete element method). The examined process is the mixing of approximately 42 thousand glass spherical particles with a 2. mm diameter in a vertical cylindrical mixer with two opposed flat blades with a 45o rake angle. The effect of different blade rotational speeds (varying from 0.1. rpm to 960. rpm) on the formation and evolution of flow patterns is investigated. Examining individual particle trajectories shows that the particles exhibit two basic types of periodic movements. The first one, characterized by a higher frequency, is related to the motion of the stirrer. The second one (lower frequency) is associated with recirculations in the vertical plane. A methodology for their detection is proposed. The observed recirculation zones are the secondary flow commonly occurring in liquid mixing cases and also the mechanism of their emergence is similar. Unlike liquids, the mixing of granular systems exhibits a greater diversity of recirculation zones. The tangential motion does not create complex structures in the angular direction, because the height of the granular layer is several times greater than the height of the blade. For this reason, we have focused only on the tangential velocity distribution in the radial and axial directions. Three global particle transport characteristics describing the mixing process in the tangential, axial and radial directions were proposed. Significant changes in the behavior of these variables were used to distinguish six dynamical regimes of granular mixing depending on the blade rotational speed. These regimes are characterized by different flow patterns.
Název v anglickém jazyce
The effect of rotational speed on granular flow in a vertical bladed mixer
Popis výsledku anglicky
Granular mixing is an important unit operation used to ensure the uniformity of mixture properties. Unfortunately, the mechanisms of particles' motion and the role of operation parameters remain poorly understood. In this work, granular mixing is studied using computer simulations via DEM (discrete element method). The examined process is the mixing of approximately 42 thousand glass spherical particles with a 2. mm diameter in a vertical cylindrical mixer with two opposed flat blades with a 45o rake angle. The effect of different blade rotational speeds (varying from 0.1. rpm to 960. rpm) on the formation and evolution of flow patterns is investigated. Examining individual particle trajectories shows that the particles exhibit two basic types of periodic movements. The first one, characterized by a higher frequency, is related to the motion of the stirrer. The second one (lower frequency) is associated with recirculations in the vertical plane. A methodology for their detection is proposed. The observed recirculation zones are the secondary flow commonly occurring in liquid mixing cases and also the mechanism of their emergence is similar. Unlike liquids, the mixing of granular systems exhibits a greater diversity of recirculation zones. The tangential motion does not create complex structures in the angular direction, because the height of the granular layer is several times greater than the height of the blade. For this reason, we have focused only on the tangential velocity distribution in the radial and axial directions. Three global particle transport characteristics describing the mixing process in the tangential, axial and radial directions were proposed. Significant changes in the behavior of these variables were used to distinguish six dynamical regimes of granular mixing depending on the blade rotational speed. These regimes are characterized by different flow patterns.
Klasifikace
Druh
J<sub>x</sub> - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)
CEP obor
CI - Průmyslová chemie a chemické inženýrství
OECD FORD obor
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Návaznosti výsledku
Projekt
<a href="/cs/project/GAP105%2F12%2F0664" target="_blank" >GAP105/12/0664: Hydromechanické interakce v soustavě tuhá fáze - tekutina</a><br>
Návaznosti
S - Specificky vyzkum na vysokych skolach
Ostatní
Rok uplatnění
2015
Kód důvěrnosti údajů
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Údaje specifické pro druh výsledku
Název periodika
Powder Technology
ISSN
0032-5910
e-ISSN
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Svazek periodika
280
Číslo periodika v rámci svazku
August 01, 2015
Stát vydavatele periodika
NL - Nizozemsko
Počet stran výsledku
11
Strana od-do
180-190
Kód UT WoS článku
000356208700020
EID výsledku v databázi Scopus
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