Problems with centrifugal separators

The separation efficiency of a settler-sedimentator is influenced by factors such as the inlet linear velocity of the sedimentator, the inlet concentration, the rotation radius, particle density, particle distribution, and gas viscosity. When the inlet linear velocity is between 15 m/s and 25 m/s, the separation efficiency is highest; however, when it exceeds 30 m/s, the pressure drop in the centrifuge increases, leading to an increase in negative pressure in the ash hopper. Excessive negative pressure in the ash hopper hinders the particles that have been recovered from entering the hopper, causing those particles to be carried up again. Since the linear velocity at the outlet of the riser reactor determines that of the inlet to the centrifuge, if this velocity is too low, the centrifuge is unable to generate sufficient centrifugal force. This can also lead to clogging in the riser reactor, interruptions in catalyst delivery, and abnormal fluidization, thereby posing a threat to safe operation. Therefore, either too high or too low a linear velocity in the riser reactor reduces the efficiency of the centrifuge.

Either too high or too low a linear velocity in the riser reactor can affect the separation efficiency of the settler and centrifuge; the optimal separation efficiency is achieved when the linear velocity at the inlet of the centrifuge is between 15 m/s and 25 m/s.