Through many years equipment practice and many accident analysis experience, there are four main reasons of the vibrating screen beam and box broken:

1) The excessive production load cause the equipment overload operation, so the equipment cann't support, it will cause the screen beam and box broken;

2) The screen mesh or other spare parts are loose when we installed, it will cause resonance, the beam and box resonance with vibrating screen will make the screen broken;

3) The equipment itself is weak because of the design reasons, and the design of the screen box steel beam is too thin to adapt to the worse production environment, resulting in cracking of the equipment; 

4) Deflective vibration of the screen makes it broken.

Combine above four reasons with the production practice, we can take below measures to solve these problems:

1) Modification of equipment failure caused by production overload 

We are considering production capacity requirements and the safety factors when we choose the equipment style to meet the production. Why is overload happening? Details are as follows:

(1) The effect of material properties

Because of the high viscosity of material, it is difficult to screen and the material will form a thick layer on the screen surface, which makes the upper layer material in the particle size cann’t be timely screening and resulting in the equipment broken. 

For this reason, we increase the inclination angle α of the vibrating screen, the material velocity V=V*sinα along the sieve surface increases with the angle α increases, and the material speed along the screen surface increases, so that the screen surface material thickness decreases, it will ensure the particle size easily passing through the sieve pore, and finally reduce the screen actual load.

(2) The influence of sieve mesh selection

In the large mining, we commonly choose the polyurethane sieve plate which include plate sieve and bar sieve. Plate sieve has long life, so many companies choose it when the material has a good property. If the material property is not good, the material will be difficult to sieve, and it is easy to cause the pore blocked, the screen beam and box broken. Because bar screen is cylindrical, the pore size is bigger than the plate sieve, so the material will be much easier to pass than the plate sieve. The overload problem of equipment caused by this factor will be solved by changing the original screen sieve plate to bar sieve plate.