Study on noise characteristics of a novel equal-thickness screen

As the key unit in coal preparation and utilization, equal-thickness screens characterized by a large capacity and high efficiency have been extensively applied in coal preparation plants. Recently, the noise pollution caused by the screening of coal has become more and more serious. Reducing the noise of vibrating screens is the key to control the noise of coal preparation plants. In this article, the noise test system was used to measure three-dimensional (3D) sound intensity of the equal-thickness screen. According to the analysis of sound intensity distribution and spectral coherence, the main sources of noise were identified. The main sources of noise of equal-thickness screen were vibration motors, side panel, screen surface and damping supports. A displacement model was fitted to the experimental data, and the kinematics of the sieve body was studied. The results showed that the amplitude of the sieve body decreased as the distance from the feeding end (towards the discharge end). Similarly, the intensity of the noise decreased about 2 dB in the same direction (from the feeding end to discharge end). However, in the direction perpendicular to the movement of the material, the noise distribution was symmetrical. Finally, various noise reduction measures were also put forth. It could be seen that when the composite spring was adopted as the damping support and the structures of vibration motors, screen surface and side panel were changed, the noise could be effectively reduced.