The automatic sludge discharge is controlled via a timer. During the sludge discharge cycle the machine tool need not be stopped. The dirty liquid is accumulated in the dirty fluid tank 2). The feed pump is switched off, and the rotor is braked until special rotor valves open. Excess process fluid leaves the rotor via these valves in the rotor wall and flows back to the dirty fluid tank.
After a quick dry spinning of the sludge, the rotor is completely stopped. A high torque gear drive scraping mechanism 6) peels the sludge off the rotor wall. The sludge falls through the open rotor bottom into a container 8). After scraping, the feed pump 3) is switched on briefly to rinse sludge remnants from the inside of the rotor. The rotor returns to its nominal speed, and the feed pump is switched on. The dirty fluid cleaning process begins again.
The feed pumps feed rate is slightly higher than the centrifuges nominal capacity thus working down the accumulated dirty liquid within the next few minutes of the processing cycle.