Discussion On Double-Frequency Composed Vibration Sieve Method

Vibration screen is a sort of sieving machine which is widely applied to roadbuilding, coal, metallurgy, petroleum, grain, etc. Most of their vibrations are periodical and forced by the centrifugal inertia force produced by the rotating excitation shaft with the eccentric block. So far as the twin-shaft vibration screen is concerned. According to operating frequency of the exciting shaft, twin-shaft vibration screen is classified as single frequency vibration screen and multi-frequency vibration screen. The double-frequency vibration screen works with two force excitation frequency. This exciting mode can enable the screening material to obtain the full caper on the entire screening surface. So it can enhance the screening efficiency. Through studying on the double-frequency composed vibration sieve method, this dissertation believe that it has the vital practical significance to enhance the performance of screening device, obtain the high grade screening product and design redundant reliability, market competitive power product.With the double-frequency vibration screen as the object of study, this dissertation has finished the following research work.1,Taking installing, disassembling conveniently parts and adjusting parameters, in order to gain parameter of the best screening efficiency as the essential target, the double-frequency composed vibration screening experiment prototype has been made, and the parameters, such as low-frequency, rate of frequency, low-amplitude, rate of amplitude and phase difference of two frequencies etc. were optimized by orthogonal test against different size material. And the major structual parameters are obtained.2,Based on the optimization of parameters parameters, the contrast test using different exciting and the discharge speed test against different dip-angle are finished, and further has been understood about the advantage and disadvantage of the double-frequency excitation mode and the choice scope of the screening surface inclination angle. Some good results are obtained.3,The dynamic model with three degrees of freedom is made and the model is solved. According to the result, analysis and simulation of moving locus for different dynamics parameters are simulated. Moving locuses of the horizontal and direction are obtained. The result shows that when the rate of frequency is 1:1, the moving locus of vibration organism center is an ellipse. This practice is consistent with the theory of twin-shaft balanced elliptical vibration screen.