Research Of Solids Conveying Of Single Screw Extruders Using The Discrete Element Method

The movement of particle system can be studied by a kind of numericalmethod which is called discrete element method (DEM). In this method, everyparticle is an analysis object, and DEM could obtain particles' movement atdifferent time. In the single screw extruder's solid conveying section, most ofsolid conveying theories of solid conveying section treat particles as a solidplug or several solid plugs which have mutual movement among them, andthese hypotheses disagree with reality of the movement of particles in solidconveying section. Using DEM can overcome the defect of plug solidconveying theory.In this paper, the solid conveying section of single screw extruders wassimulated by EDEM and the DEM program which was developed by thepresent author, compared with experiment results and the results obtainedfrom plug solids method validated the effectiveness of discrete elementmethod; the results obtained through changing the diameter of particles insimulations exhibited that there was an suited diameter of particle for thesingle screw extruder optimal output. effects of friction coefficient on outputwas studied by changing friction coefficient between particles and barrel. Velocity distribution of particles revealed that these was several layers ofvelocity along the radial; through changing the screw speed, effects of screwspeed on output were studied, and the velocity distribution in width directionwas also observed; trajectory was studied by several tracers signed bydifferent color, and some factors were also studied which affected the outputstability.