Research on the New Drive of a Laboratory Screen with Rectilinear Vibrations in Transient States

Abstract

The paper presents the results of research on the vibrating motion of a laboratory screen with a rectilinear (segmental) trajectory of vibrations during its start-up and braking. The investigations were carried out on a modernized stand equipped with a system of two vibrating motors applied in newer solutions of industrial screens, which are mounted directly on the riddle. The tests were carried out for three different frequencies using three-axis acceleration sensors. The analysed parameter was the increase in the amplitude of vibrations in transient states compared to the amplitude during the stable operation of the device. The maximum multiplication of the vibration amplitude of the classic drive system during start-up was 9.7 (mm/mm) in the vertical direction and 5.7 (mm/mm) for the new system. During braking, the maximum multiplication of the vibration amplitude of the classic drive system was 6.9 (mm/mm) vertically, while for the drive system with vibration motors, it was 11.4 (mm/mm). The absence of flexible couplings in the drive system reduces the damping of vibrations and increases the value of amplitude during the start-up and free braking of the machine. This does not have a major influence on the correct operation of the machine in a steady state. However, the use of the new drive system resulted in a significant reduction in power demand and shortened the start-up time, which has a positive effect on the operating costs of the machine.

The Impact of Vibrating Screen Startup Time on Vibration Amplitude and Energy Consumption in Transient State

“…During startup, this amplitude will be higher and dependent on damping and primarily on the time and manner of passing through resonance. Amplitude studies during startup are presented in the article [16], although they did not account for the startup time and its impact on electrical power consumption. As seen from Figure 3, at the resonance frequency, the amplitude of the screen's vibrations tends toward infinity, and beyond this frequency, it rapidly decreases and approaches a constant value.…”

“…During startup, this amplitude will be higher and dependent on damping and primarily on the time and manner of passing through resonance. Amplitude studies during startup are presented in the article [16], although they did not account for the startup time and its impact on electrical power consumption.…”

“…Elastic support systems are employed to reduce dynamic effects on the foundation [14]. The vibrating motion of the sieve frame is driven by a drive system, typically consisting of an electric motor, flexible couplings, and an inertia vibrator or vibratory motors [15,16], occasionally electromagnetic ones [17]. In super resonant screens in which an inertial vibrator generates vibrations, the value of the vibration amplitude depends on the mass of elements (weights) attached to the vibrator shafts (or unbalanced masses in the vibration motor).…”

“…The operation of a screening machine can be divided into three stages: startup [16], steady-state operation [15], and shutdown. The startup phase refers to the period from the drive initiation until the rated vibration frequency is reached and the parameters of the sieve frame vibrations stabilize.…”

Comparative Analysis of Dust and Noise Emission in Aggregate Production Systems

“…This is due to the nature of the operational characteristics of crushing and screening devices. Both crushers and screens consist of a number of movable parts and components that rotate with a considerable speed, often with eccentric movement, which may contribute to intense vibrations [7,8]. In general, crushing and screening operations are of a high negative impact both on the environment and humans, and due to their high energy consumption they indirectly contribute to higher emission of carbon dioxide CO 2 and other nuisances [9][10][11].…”