A method and system for controlling the apex flow of a multihydrocyclone for fiber suspensions

摘要

The invention relates to a method of controlling an apex flow in a hydrocyclone unit (9), and a control system for carrying out the method. The hydrocyclone unit (9) comprises a plurality of hydrocyclone separators (10) in parallel, and further comprises an inject chamber (21, 22, 23), base chamber and apex-fraction chamber common to all separators, an inlet (1) to the inject chamber (21) and an outlet (2, 3) for the base chamber (22) and apex chamber (23) respectively. The apex flow is controlled by automatically and substantially continuously detecting at a location in or adjacent the apex outlet (1) a flow parameter of the apex fraction, and comparing this sensed flow parameter value with a set-point value, and changing the setting of a valve (15) incorporated in a conduit (14) connected to the apex outlet (2) when the sensed value deviates from the set-point value, so that the flow parameter value of the apex fraction moves towards the set-point value.