A method and a system for purification of contaminated oil. The method comprising providing contaminated oil into a disc stack centrifugal separator (3). The disc stack centrifugal separator comprises a light phase outlet chamber (33) and/or a heavy phase outlet chamber (31) in which a fluid level can be controlled. Separating the contaminated oil in the disc stack centrifugal separator (3) into a light phase and a heavy phase. Measuring one or more properties in a light phase retrieved from the disc stack centrifugal separator (3), wherein said one or more properties comprise one or more of a density, a viscosity, an amount of heavy phase content and a flow rate of the light phase. Controlling a backpressure provided to a heavy phase outlet (5b) and/or a light phase outlet (5a) of the disc stack centrifugal separator (3) and hereby controlling a fluid level in the heavy phase outlet chamber (31) and/or light phase outlet chamber (33), said controlling being dependent on at least one value of said one or more measured properties.

A solid bowl centrifuge has a centrifuge bowl that can be rotated in a rotational direction about a longitudinal axis during operation. An end face of the centrifuge bowl has at least one flow-off opening for the flow-off of clarified material from the centrifuge bowl. A dam edge bounds the flow-off opening in the radially outward direction, and an energy recovery device is located on the dam edge for recovering energy of the clarified material flowing. The dam edge is pivoted toward the rotational direction at least in some sections, as viewed from the longitudinal axis.

A solid-bowl screw centrifuge has a centrifuge drum that is rotatable about a longitudinal axis, at least one outlet for discharging clarified material from the centrifuge drum, and an energy recovery device, arranged at the outlet, for recovering energy from the discharged clarified material, when the solid-bowl screw centrifuge is in operation, the centrifuge drum can rotate in a first direction of rotation and in a second direction of rotation opposite to the first direction of rotation. The energy recovery device has a first active surface, via which clarified material can flow out when the centrifuge drum is rotated in the first direction of rotation, and a second active surface, via which clarified material can flow out when the centrifuge drum is rotated in the second direction of rotation.

A decanter centrifuge with a rotating bowl is provided with at least one solids discharge port and at least one clarified liquid discharge port and a screw conveyor disposed coaxially within the rotating bowl to be rotated in the same direction with a differential rotational speed. A feed suspension to be separated is introduced into a ring shaped space formed between the rotating bowl and the screw conveyor through a central feed pipe fixed to the end of the screw conveyor and supported in at least one bearing. The feed suspension is separated by centrifugal force into a solid phase and a liquid phase so that the solid phase is discharged from the solid discharge port and the liquid phase is discharged from a clarified liquid discharging apparatus. A sealing of the feed pipe and the bowl shaft at the feed end of the feed pipe is provided as adjacent double axial sealing. A liquid phase conduit is arranged in the bowl shaft for guiding the liquid phase outside of the bearings, and a liquid phase valve is provided outside the bearing on the side facing away from the bowl and screw. In this way the liquid phase discharge valve can be varied during operation of the decanter centrifuge by a hand wheel via a transmission or by a motor.

A rotating machine has a bowl that is rotatable about an axis to generate a cylindrical pool of a feed slurry. The bowl has a heavy phase discharge port and a base plate at one longitudinal end of the bowl. There is at least one outlet opening in the base plate and a liquid phase discharge port member positioned over the outlet opening. The liquid phase discharge port member includes at least one open straight channel having a longitudinal axis that extends at an acute angle relative to the base plate. The channel has an extension in the direction of the longitudinal axis of open straight channel.

A centrifugal separator has a rotary drum that is adapted to receive a product that can be separated into a light phase, a heavy phase, and solid sediments, a first outlet for the light phase, a closing device that opens and closes a second outlet for the heavy phase. The closing device has an electromagnetic actuator having a ferromagnetic element whereon a closing plug is mounted. The electromagnetic actuator has an electromagnetic coil that creates a magnetic field so as to attract the ferromagnetic element. A spring is connected to the closing plug so as to urge the closing plug to a closed position. The closing plug, the ferromagnetic element and the spring are connected to the rotary drum.

A centrifuge, including: a flange closing off one axial end of a separation chamber; a plurality of apertures that traverse axially through the flange at a radial distance from a flange axis, wherein at least one aperture is in fluid communication with a first outlet passage; a plurality of weir inserts removably disposed within the plurality of apertures to control a flow of one or more fluids from the separation chamber; wherein at least one weir insert disposed within the at least one aperture in fluid communication with the first outlet passage is changeable to prevent or allow fluid communication between the separation chamber and the first outlet passage.

A method of producing a low-fat product from a starting material made of a fat and/or oil containing plant- or animal item includes providing the starting material at a temperature of at least 35 C. and extracting a greater part of the extractable oil and/or fat originally contained in the plant or animal item from the starting material using a first decanter centrifuge. The first decanter centrifuge leaves a residue of solids and liquids. The residue forms the low-fat product.

A solid bowl centrifuge includes a screw that rotates during operation, a solid material discharge, and at least one liquid outlet, which has a device for influencing an immersion depth in the separation chamber or the diameter of a separation zone in the separation chamber. The device includes one or more pressure chambers, into which a respective fluid supply line feeds, via which a gas pressure in the respective pressure chamber can be influenced such that, in the respective pressure chamber, the gas pressure is to be applied to at least one liquid surface of the exiting liquid phase, in order to influence the diameter, the immersion depth, and/or the diameter of the separation zone in the drum during operation. Respective pressure chambers are formed in the rotor. One or more functional discs are arranged in the region of the respective pressure chamber and all rotate along with the rotor.

A centrifugal separator includes a rotating body rotating in use around an axis. The rotating body comprises a bowl, which comprises a base at one longitudinal end of said bowl, said base defining a rear longitudinal area. An outlet passage extends through the base and an outlet housing is provided in the rear longitudinal area. The outlet housing is communicating with the outlet passage to receive liquid therefrom and the outlet housing has an outlet opening discharging in use liquid from the rotating body. The outlet opening comprises a weir edge defining in normal use a level of a surface of a liquid in the bowl. The outlet housing is rotatable around an adjustment axis and the outlet opening is placed in a side wall offset from the adjustment axis.