Innovative structural solution for heavy loaded vibrating screens

An innovative design solution is presented in this paper; it allows the enhancement of structural resistance and the dynamic performances of a vibrating screen for inert materials. The new design does not significantly affect the geometry of the traditional screens, keeping the same global dimensions and almost the same mass value. In fact the aim of this study was to design a new vibrating screen having almost the same dimensions but that could give a much higher dynamic structural resistance at frequencies and load amplitudes much higher than the nominal ones. Numerical finite element models were generated to investigate the structural and dynamic behavior of a standard vibrating screen. These analyses allowed the modification of the geometrical parameters of the traditional screen and to design the new one. Accurate three-dimensional FE models were so generated in order to evaluate the best design solution, in terms of dynamic structural resistance, able to reduce the stress values at the most stressed area. The fatigue resistance of all the components of the new screen was checked, with particular attention to the welding joints. Experimental full scale tests on a prototype of the new screen were carried out in order to validate the numerical models and mostly to verify the structural integrity of the vibrating screen during the working conditions. Strains at the surface of the most stressed areas of the screen were measured in dynamic working conditions, at different frequencies and load amplitudes; these stress values were compared with the numerical ones in order to validate the numerical results. The new screen was patented.