Premium
Unsteady Mixing Characteristics in a Vessel with Forward‐Reverse Rotating Impeller
Author(s) -
Woziwodzki S.
Publication year - 2011
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.201000455
Subject(s) - baffle , impeller , mixing (physics) , mechanics , rushton turbine , drag , materials science , rotation (mathematics) , power (physics) , oscillation (cell signaling) , turbine , mechanical engineering , physics , chemistry , engineering , thermodynamics , mathematics , quantum mechanics , biochemistry , geometry
Usually, mixing is carried out in a vessel with four baffles and a single impeller. In some applications, however, the use of a baffled vessel is not recommended. One of the stirring methods used instead is unsteady agitation with forward‐reverse rotating impellers. The aim of this work was to characterize the agitation characteristics in a baffled and an unbaffled vessel with a turbine impeller. Mixing time and mixing power were evaluated in relation to the presence of baffles and the frequency of forward‐reverse rotation. It was found that the frequency of oscillation does not affect either the mixing time and mixing power values or the drag and added mass coefficients. Power requirements and mixing time were higher compared to the steady mixing conditions in a baffled vessel. The results showed that it is not recommended to use baffles because they have no influence on unsteady mixing.