A centrifugal separator includes a frame and a drive member configured to rotate a rotating part in relation to the frame around an axis of rotation. The rotating part includes a spindle and a centrifuge rotor enclosing a separation space. The rotating part is supported by the frame by at least one bearing device. The centrifugal separator further includes a system for detecting rotation of the rotating part. The system includes at least one first type of sector each occupying a first length of the perimeter of a member arranged for rotation with the rotating part, and at least one second type of sector each occupying a second length of the perimeter of the member arranged for rotation. The at least one second type of sector is spaced apart from the at least one first type of sector. The second length is different compared to the first length. The at least one first and second types of sectors are irregularly spaced around the perimeter of the member arranged for rotation. The system further includes an inductive sensor arranged to detect the at least one first and second types of sectors and give rise to a binary pulse sequence upon rotation of the member arranged for rotation. The temporal widths of the binary pulses correspond to the lengths of the at least one first and the at least one second types of sectors, respectively.

A centrifugal separator includes a frame and a drive member configured to rotate a rotating part in relation to the frame around an axis of rotation. The rotating part includes a spindle and a centrifuge rotor enclosing a separation space. The rotating part is supported by the frame by at least one bearing device. The centrifugal separator further includes a system for detecting rotation of the rotating part. The system includes at least one first type of sector each occupying a first length of the perimeter of a member arranged for rotation with the rotating part, and at least one second type of sector each occupying a second length of the perimeter of the member arranged for rotation. The at least one second type of sector is spaced apart from the at least one first type of sector. The second length is different compared to the first length. The at least one first and second types of sectors are irregularly spaced around the perimeter of the member arranged for rotation. The system further includes an inductive sensor arranged to detect the at least one first and second types of sectors and give rise to a binary pulse sequence upon rotation of the member arranged for rotation. The temporal widths of the binary pulses correspond to the lengths of the at least one first and the at least one second types of sectors, respectively.

Accurate measurement of acceleration caused by imbalance in the balance of a rotor is realized even in high-speed rotation with an acceleration sensor which has a processing speed required in low-speed rotation and a control unit. A centrifuge according to the present invention includes a rotor, a drive source for rotating the rotor, a rotating shaft for coupling the rotor and the drive source, an acceleration sensor, and a control unit. The acceleration sensor outputs values indicating acceleration in two different directions which are perpendicular to an axial direction of the rotating shaft. The control unit obtains an acceleration corresponding value, which is a value corresponding to acceleration in a direction perpendicular to the axial direction of the rotating shaft, based on values indicating acceleration in the two different directions and stops rotation of the rotor in a case where the acceleration corresponding value satisfies a determination criteria.

Accurate measurement of acceleration caused by imbalance in the balance of a rotor is realized even in high-speed rotation with an acceleration sensor which has a processing speed required in low-speed rotation and a control unit. A centrifuge according to the present invention includes a rotor, a drive source for rotating the rotor, a rotating shaft for coupling the rotor and the drive source, an acceleration sensor, and a control unit. The acceleration sensor outputs values indicating acceleration in two different directions which are perpendicular to an axial direction of the rotating shaft. The control unit obtains an acceleration corresponding value, which is a value corresponding to acceleration in a direction perpendicular to the axial direction of the rotating shaft, based on values indicating acceleration in the two different directions and stops rotation of the rotor in a case where the acceleration corresponding value satisfies a determination criteria.

A control method for a centrifuge is performed by a motor drive unit to drive a motor of the centrifuge using pulses from an angle sensor. The method has a start phase, a regulated acceleration phase, a holding phase, a regulated deceleration phase, a regulated gentle deceleration phase, and a position adjustment phase.

A control method for a centrifuge is performed by a motor drive unit to drive a motor of the centrifuge using pulses from an angle sensor. The method has a start phase, a regulated acceleration phase, a holding phase, a regulated deceleration phase, a regulated gentle deceleration phase, and a position adjustment phase.

A centrifugal separator includes a housing and a rotary vessel having an axis and being attached to the housing for rotation relative to the housing about the axis. Either: a) the rotary vessel has one or more magnetisable regions and the housing has one or more electromagnetic windings; or b) the rotary vessel has one or more electromagnetic windings and the housing has one or more magnetisable regions. The electromagnetic windings are selectively energisable to create a magnetic field to cause rotation of the rotary vessel.

A centrifugal separator includes a housing and a rotary vessel having an axis and being attached to the housing for rotation relative to the housing about the axis. Either: a) the rotary vessel has one or more magnetisable regions and the housing has one or more electromagnetic windings; or b) the rotary vessel has one or more electromagnetic windings and the housing has one or more magnetisable regions. The electromagnetic windings are selectively energisable to create a magnetic field to cause rotation of the rotary vessel.

A centrifugal separator includes a rotor arrangement and a drive arrangement. A user of electric energy is arranged in the rotor arrangement. The centrifugal separator includes a rotary transformer, the rotary transformer including a transformer stator and a transformer rotor. The transformer stator and the transformer rotor are arranged adjacent to each other with an airgap therebetween. The transformer rotor includes a secondary coil and is rotatable together with the rotor arrangement. The secondary coil is electrically connected to the user of electric energy arranged in the rotor arrangement for providing the user of electric energy with an electric current. The user of electric energy may be an actuator, and/or a sensor, and/or a control unit.

A vertical cuttings dryer (VCD) can be used to separate solid particulate from entrained liquid. In some examples, the VCD includes a screen mounted coaxially with an internal wiper housing that carriers a wiper sweeping out an annular space between the screen and wiper housing. The VCD may have a first motor connected through drive shaft to the screen and a second motor connect through a separate drive shaft to the wiper housing. A controller can independently control the speed of the first motor and the second motor to independently a magnitude of centrifugal force applied to material being processed as well as a residence time of the material being processed in the annular space.