Research Of Vibratory Feeder’s Particle Motion And Correction Scheme In Eccentric State

In the rotary hearth furnace direct (RHF) reduction process, the thickness and distribution of carbon pellets on the furnace has a direct impact on the quality and productivity of sponge iron. Scholars designed a new type of vibratory feeder, which could make pellets distribute with equal thickness on the furnace along circumferential and radial direction. But in practice, the vibratory feeder can’t distribute pellets with a constant thickness in eccentric state, and can’t reach the process requirements of RHF. So the problem of uneven distribution caused by eccentric was studied; the mechanisms of this phenomenon were explored and the correction schemes of vibratory feeder were looking for from the characteristics of eccentric vibration and particle motion in this paper.On the basis of the in-depth analysis on the structure, principle and vibration characteristics of the vibratory feeder, the phenomenon that the center of mass and the exciting force line don’t overlap was defined as the eccentric. Then a coupled vibration model with five degree of freedom was constructed; the steady-state response to different eccentric state was solved by mode superposition method; the relation curves between eccentricity and steady-state amplitude were obtained by numerical computation using MATLAB; the influence of eccentric on vibration characteristics of vibratory feeder was analyzed.The kinetic theory of the material particle in vibratory feeder was deduced in the linear vibration conditions. Then a friction model which is suitable for the simulation of particle motion was established; the motion of a particle in complex vibration conditions were simulated after the friction model was embedded into the ADAMS by user subroutine written in FORTRAN77; the influence of vibration caused by eccentric on the motion of the material particle in vibratory feeder was analyzed.Combining eccentric vibration characteristics of vibratory feeder and movement of pellet, the influence of eccentric on the effect of pellet distribution was analyzed; and the phenomenon of uneven distribution caused by vibratory feeder eccentric was explained. Then the multi-particle motion simulation of vibratory feeder in different eccentric state was performed; the relations between the distribution of pellets and eccentric were found; and two correction schemes which would be tested subsequently were proposed.The results show that, horizontal eccentric is the root cause of the phenomenon of uneven distribution; and the distribution of pellets is significantly improved after correction, which proves the correctness of the theoretical analysis.