| Triangle arrayed triple-screw extruder (hereinafter to be referred astriple-screw extruder, TTSE for short), as the one of mixing equipments,is received more and more attention. At present, the studies of the mixingperformance of TTSE still lack systematic analysis, some simulatedstudies are just based on steady-state flow fields, and lack experimentalverification. This thesis tried to set up a relationship of contrast betweennumerical and experimental results that obtained under the sameconditions to verify the reliability of the simulation, and then comparedthe mixing performances between TTSE and TSE, and then studied theinfluences of different factors on TTSE. Using this method from point toline and then from line to surface, and to system finally, an integratedsystem was established to evaluate the mixing performance oftriple-screw extruder, which has a certain guiding significance. The maincontents in the thesis are as follows: 1. This thesis carried out axial pressure and RTD testing experimentsunder different conditions, and then made the comparison betweensimulated and experimental results, the reliabilities of simulationswere proved.2. This thesis simulated the steady-state and time-dependent flow fieldsof TTSE and TSE. The results show that: backflow ratio of TTSE is2.4times that of TSE, and the average residence time of TTSE is1.6times that of TSE; the average shear rate of TTSE is a little more thanTSE, but the average stretching rate is1.5times that of TSE; theaverage number of particles that flow through the kneading zone ofTTSE is1.55times that of TSE, the nubmer of particles in TTSE thatexperience maximum shear stress and maximum mixing index is morethan that of TSE.3. This thesis first simulated steady-state flow fields of different factors(screw elements’ type, kneading block’ geometric parameters andscrew element combination), Combining with the above work, anintegrated system was initially established to evaluate the mixingperformance of triple-screw extruder. |
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