Centrifugal separator and method for determining suitable moment for removal of heavy phase content

Abstract

A centrifugal separator for separating a fluid mixture into components, including a non-rotating part, a rotor which is attached to a shaft which is rotatably supported in the non-rotating part around a rotational axis, which rotor forms within itself a separation space delimited by a rotor wall. The separator includes an inlet extending into the rotor for supply of a fluid mixture to be separated in the separation space, at least one sensor measuring unbalance conditions in the frame; a level determining arrangement including two or more space defining elements of arbitrary form arranged on the interior surface of, or close to, the rotor wall, where each space defining element defines a space which communicates with the separation space or another of the space defining elements through at least one inlet opening arranged at a certain radius from the rotational axis and not outside that radius and where that certain radii of the space defining elements are different. Methods for determining when a predetermined amount of heavy phase fluid (purification) or sludge (clarification) has been separated are also disclosed. The separator and methods make it possible to determine when the level of separated heavy phase fluid or sludge is high enough for emptying or discharge of the separator.