News & Updation
VIBRATION ANAYSIS OF A VIBRATORY SCREENING MACHINE
Oriaku, E.C. *, Agulanna, C. N, Ibeagha D. C, Adizue, U.L, Madubuko, E. C.
A vibratory system is a dynamic system for which the variables such as excitations (inputs) and responses (outputs) are time dependent. The response of a vibrating system generally depends on the initial conditions as well as the external excitation. Most practical vibratory systems are very complex, and it is impossible to consider all the details for a mathematical analysis. Only the most important features are considered in the analysis to predict the behavior under specified input conditions. Often, the overall behavior of the system can be determined by considering even a simple model of a complex physical system. In this work, a vibratory screening machine with two distinct sieve sizes of 0.25mm and 0.5mm was designed and fabricated. The average efficiency of the two sieve sizes under the same load condition was found to be 95% respectively. The responses of a forced, damped harmonic vibration with double degree of freedom (Vibration of Screen and frame) in the vertical direction of the designed vibratory screening machine were analyzed. The governing equations are derived, solved and results interpreted. The inputs into the system include the following; Mass of the machine frame (M1) = 35kg; mass of the vibratory screen with load M2 ranging from [20-30] kg at incremental intervals of 2kg; Equivalent Spring Constant for frame K1 = 25000N/m and Screen K2 = 16350N/m; Damping Constant, C2 = 20Ns/m; Static deflection force Fo = 2409.8N. The responses monitored are as follows: Particle discharge time through the sieve (t) ranged (1032 – 1744 secs); Particle flow rate through the sieve ranged from (0.896 ×10-4- 2.8 ×10-4) kg/sec; Phase Angle ? ranged = (0.0150 – 0.10); frequency ratio w/wn ranged from 9.3 -9.87, Amplitude of vibration (X) = 8.57×10-4 – 5.71 ×10-4m. These determinedparameters affect the efficiency of screening and can act as basis for the optimization of the system for other various load conditions.[Full Text Article]