Vibration reduction measures for mine vibrating screen | circular vibrating screen

Vibrating screen | circular vibrating screen will generate high-frequency vibration during the working process, and it will also be accompanied by noise, which is unavoidable. Considering each aspect, here is a summary from the structural design to the adoption of some measures to reduce vibration.

1 Vibration isolation

If an elastic pad (vibration isolator) is arranged between the vibration equipment and the supporting structure, only part of the disturbance force is transmitted to the structural member through the vibration isolator. The vibration isolation effect is measured by the vibration isolation coefficient. The smaller the vibration isolation coefficient, the better the vibration isolation effect. To obtain a better vibration isolation effect, the natural frequency of the system is required to be small, so a material with better elasticity must be used as the vibration isolation pad, such as a soft spring or rubber vibration isolation pad.

2 Reasonable selection of structural stiffness

The common method to increase the structural stiffness is to shorten the length of the member, increase the cross-sectional size, and strengthen the end connection of the member. For example, the beam end supporting the mine vibrating screen/circular vibrating screen is rigidly connected directly to the retaining wall, so that the vibration of the floor slab is significantly reduced. Considering the combined effect of beam and slab stiffness in the design, the design thickness of the floor slab should be increased.

3 Reasonable arrangement of equipment

Since the natural vibration frequency of the system decreases with the increase of the static displacement of the structure, if the mining vibrating screen/circular vibrating screen is placed at the place where the maximum displacement occurs, the natural vibration frequency is the smallest and the period is the largest, which is the most favorable. The layout should be conducive to the direction of the disturbance force. Most of the screening buildings in the coal industry are multi-layer single-span reinforced concrete frame structures. The span is generally 5m or 6m, and the lateral horizontal rigidity of the frame is poor. When installing a mining vibrating screen/circular vibrating screen, the direction of movement of the screen should be adjusted parallel to the longitudinal direction of the structure. The heavier mining vibrating screen/circular vibrating screen should be placed in the lower layer of the structure as much as possible. For the floor structure with multiple mine vibrating screens/circular vibrating screens, the influence of the synthetic vibration of the floor structure shall be considered.

4 Structural Design

The structural design should consider the possibility of changing the natural vibration frequency to adapt to the product development of the workshop and the renovation of machinery and equipment.

5 Using damping force to limit the effect of structural vibration

The damping force is beneficial to the attenuation of the system vibration, and sometimes it is necessary to try to increase the damping to accelerate the attenuation of the vibration.

6 Other structural measures

The supporting members should bear a simple, reasonable, and regular appearance, and try to adopt rectangular cross-section; the midpoint static deflection of the longitudinal and transverse beams supporting the vibration equipment should be as close as possible to avoid eccentric loads as much as possible to reduce the torsional force on the beams. The design of structural components should be compared with multiple schemes. The steel bar material should be hot-rolled deformed steel bar as far as possible, cold-rolled steel bar should not be used, and welded joints should be avoided in the vibration-affected parts.