How a decanter centrifuge works

Measures to deal with the vibration balance of the decanter centrifuge: After summarizing the actual maintenance experience on site, it is found that the main reason for the large vibration value of the horizontal screw centrifuge is the unbalanced vibration of the rotating parts caused by the wear of the inner wall of the drum. After taking corresponding measures, the problem of large vibration of the unit is completely solved, and the reliable and stable operation of the unit is ensured.

The working principle of the decanter centrifuge: when the suspension to be separated is fed into the drum from the hollow shaft, the basic structure of the decanter centrifuge is under the action of the centrifugal force generated by the high-speed rotation.

Immediately throw it into the drum cavity; the high-speed rotating drum generates a strong centrifugal force, and the solid phase particles higher than the liquid phase density are placed on the inner wall of the drum to form a solid layer (due to the ring, also known as the solid ring layer); due to the small density, the centrifugal force is small, The liquid layer can only be formed in the solid ring layer, which is called the liquid ring layer; due to the different speeds of the spiral and the drum, both have relative motion (that is, the speed difference), using the relative motion of the spiral and the drum, the solid ring layer is The sludge is slowly pushed to the cone end of the drum, and after passing through the drying area, the outlet distributed around the drum is continuously discharged; the liquid in the liquid ring layer is continuously overflowed from the weir mouth by gravity and discharged to the outside of the drum to form a separation liquid. How the horizontal screw centrifuge works

The main reasons for the vibration of the decanter centrifuge:

There are many reasons for the large vibration of the decanter centrifuge. Combined with the maintenance experience of the decanter centrifuge on site, the following aspects are obtained:

1. The rotor dynamic balance is poor.

The root cause of the poor dynamic balance of the decanter centrifuge rotor is the rotor quality deviation. The manufacturer's unit data requires the rotor dynamic balance deviation to be 3g, and the actual verification is within 2g or even mg. If the mass deviation of a certain point on the drum is 4g, the rated speed is 4500r/min, and the diameter of the drum is 600mm, the eccentric force (F) is 266.21kg. See (1) for the calculation formula. It can be seen that small mass deviations on the rotor generate large eccentric forces. This eccentric force is the root cause of the large vibration of the decanter.

2. The drum is blocked inside.

If the inner wall of the bowl of the centrifuge is not cleaned, the aggregate in the bowl will slowly deposit on one side of the bowl, and when it is restarted, it will generate a lot of vibration, and even alarm and stop. If the downtime is too long, the material is denatured and bonded, and it can only be disassembled and cleaned. The feed chamber should also be cleaned when the feed chamber of the auger accumulates more material when the drum is disassembled.

If the viscosity of the material is too large, the fluidity is poor, or the feeding amount is too large, the material cannot be discharged in time, and the material will accumulate along the spiral path, which will also cause a certain eccentric force.