Strength And Vibration Analysis Of Screw Conveyor Of Decanter Centrifuge

In a decanter centrifuge, the screw conveyor is the key component whose structure, materials and parameters determine the throughput, separation efficiency and working life of the centrifuge. So it is significant to analyze the strength, deformation and vibration of screw conveyor.In this thesis, a parameterized 3-D finite element model of the screw conveyor is established by Solid45 elements of ANSYS. With the model, both static and modal analyses are carried out and the influence of the structural parameters on the stress intensity and deformation of the conveyor is analyzed.Under normal operation conditions, there are three types of loadings applied on the screw conveyor, namely normal pressure, frictional force and the centrifugal force. Stress and displacement fields induced by those loadings are obtained by performing static analysis. The strength of screw conveyor is checked with referring to the code for pressure vessel design by analysis. Both axial and radial displacements are also compared with the allowable values.The natural frequencies and corresponding vibration modals of the screw conveyor are obtained by performing modal analysis. Based on theresults it is concluded that resonance of the centrifuge will not happen in the normal rotational speed range.By changing the value of the blade thickness, cone angle, lead and height of fillet weld, influences of these parameters on the strength and displacement of the screw conveyor are investigated which form the base for optimization of the conveyor structure.