Centrifugal separator and method of operating the same

A centrifugal separator comprising a rotor having a separating chamber and an inlet for supplying said chamber with a mixture of light and heavy liquids, the rotor being operable to form in said chamber an interface layer between separated light and heavy liquids of said mixture, first and second outlet means for discharge of separated light and heavy liquids, respectively, from said separating chamber, said second outlet means including a channel extending radially inward from an inlet opening of the channel located in the radially outer part of the separating chamber, control means for initiating dishcarge through said second outlet means in response to movement of said interface layer radially inward to an inner level in the separating chamber, said layer moving radially outward when heavy liquid is discharged through said second outlets means, and a control unit operable to stop said discharge through the second outlet means when the outwardly-moving interface layer reaches an outer level located radially inward of said inlet opening of said channel.

The separator of claim 16, in which said control unit is operable to close the valve a predetermined period of time after it is opened.

In the operation of a centrifugal separator having a rotor with a separating chamber and an inlet to said chamber for a mixture of light and heavy liquids to be separated, and first and second outlet means for discharge of separated light and heavy liquids, respectively, from said chamber, said second outlet means including a channel extending radially inward from an inlet opening of the channel located in the radially outer part of the separating chamber, the method which comprises feeding the mixture through said inlet while driving the rotor to maintain in said chamber an interface layer between separated light and heavy liquids and while discharging separated light liquid through said first outlet means, initiating discharge through said second outlet means when said interface layer moves radially inward to a predetermined inner level in the separating chamber, allowing the interface layer to move radially outward during said discharge through the second outlet means when a predetermined amount of heavy liquid has left the separating chamber through the second outlet means.

In the operation of a centrifugal separator having a rotor with a separating chamber and an inlet to said chamber for a mixture of light and heavy liquids to be separated, and first and second outlet means for discharge of separated light and heavy liquids, respectively, from said chamber, said second outlet means including a channel extending radially inward from an inlet opening of the channel located in the radially outer part of the separating chamber, the method which comprises feeding the mixture through said inlet while driving the rotor to maintain in said chamber an interface layer between separated light and heavy liquids and while discharging separated light liquid through said first outlet means, initiating discharge through said second outlet means when said interface layer moves radially inward to a predetermined inner level in the separating chamber, allowing the interface layer to move radially outward during said discharge through the second outlet means, and stopping said discharge through the second outlet means when the outwardly moving interface layer reaches an outer level located radially inward of said inlet opening of the channel.