A centrifugal separation container which is revolved around a rotation axis, includes: a separation part which includes a distal region which is disposed on a distal side than a liquid-to-be-treated supply port and a proximal region which is disposed on a proximal side than the liquid-to-be-treated supply port, with respect to the rotation axis, and in which a liquid-to-be-treated discharge port is provided in the proximal region; and a recovery part which is disposed on a distal side than the distal region with respect to the rotation axis, communicates with a distal end portion of the distal region through a communication path, and is filled with a recovery liquid for dispersing dispersoids that are to be centrifuged in a liquid to be treated.

A centrifugal separation container which is revolved around a rotation axis, includes: a separation part which includes a distal region which is disposed on a distal side than a liquid-to-be-treated supply port and a proximal region which is disposed on a proximal side than the liquid-to-be-treated supply port, with respect to the rotation axis, and in which a liquid-to-be-treated discharge port is provided in the proximal region; and a recovery part which is disposed on a distal side than the distal region with respect to the rotation axis, communicates with a distal end portion of the distal region through a communication path, and is filled with a recovery liquid for dispersing dispersoids that are to be centrifuged in a liquid to be treated.

A method for cleaning fuel oil for a diesel engine includes providing a fuel oil to be cleaned, supplying said fuel oil to be cleaned to a centrifugal separator, and cleaning said fuel oil in the centrifugal separator to provide a clean oil phase. The method further includes measuring the viscosity of the fuel oil to be cleaned before cleaning in said centrifugal separator or the viscosity of the clean oil phase, and regulating the temperature of the fuel oil to be cleaned based on said measured viscosity.

A method for cleaning fuel oil for a diesel engine includes providing a fuel oil to be cleaned, supplying said fuel oil to be cleaned to a centrifugal separator, and cleaning said fuel oil in the centrifugal separator to provide a clean oil phase. The method further includes measuring the viscosity of the fuel oil to be cleaned before cleaning in said centrifugal separator or the viscosity of the clean oil phase, and regulating the temperature of the fuel oil to be cleaned based on said measured viscosity.

A system for extracting nutrients from raw manure comprises: a manure pump for transferring manure from a reception pit to a rotary cutter configured to cut fibers of the raw manure to a desired length to generate a manure slurry. The manure slurry is transferred to a preprocessing tank having an agitator for agitating the manure slurry. An infeed pump transfers the manure slurry from the preprocessing tank to a decanter centrifuge, the centrifuge having at least one solid outlet and at least one liquid outlet. A control system controls a flow of the raw manure from the manure pump to the rotary cutter, and from the rotary cutter to the preprocessing tank, the infeed pump and the decanter centrifuge, and also controls each of these elements of the system. A nutrient content of the resulting liquid centrate is reduced by at least 50% as compared to the raw manure.

A system for extracting nutrients from raw manure comprises: a manure pump for transferring manure from a reception pit to a rotary cutter configured to cut fibers of the raw manure to a desired length to generate a manure slurry. The manure slurry is transferred to a preprocessing tank having an agitator for agitating the manure slurry. An infeed pump transfers the manure slurry from the preprocessing tank to a decanter centrifuge, the centrifuge having at least one solid outlet and at least one liquid outlet. A control system controls a flow of the raw manure from the manure pump to the rotary cutter, and from the rotary cutter to the preprocessing tank, the infeed pump and the decanter centrifuge, and also controls each of these elements of the system. A nutrient content of the resulting liquid centrate is reduced by at least 50% as compared to the raw manure.

A method for determining if air is trapped within a centrifugal separator, the separator including a stationary frame, a rotatable assembly, a drive unit for rotating the rotatable assembly relative the frame around an axis of rotation, a feed inlet for supply of a liquid mixture to be separated, a first liquid outlet for discharge of a separated liquid phase and a second liquid outlet for discharge of a heavy phase having a density that is higher than said liquid phase. The rotatable assembly includes a rotor casing enclosing a separation space in which a stack of separation discs is arranged to rotate around a vertical axis of rotation. The method includes closing one of the first and second liquid outlets and restricting the flow from the other outlet; supplying feed to the feed inlet and measuring the flow to the feed inlet and the flow from the restricted outlet; comparing the flow as a function of time between feed inlet and the restricted outlet; and determining that air is trapped within the centrifugal separator if the measured flow as a function of time flow deviates between feed inlet and the restricted outlet.

A method for determining if air is trapped within a centrifugal separator, the separator including a stationary frame, a rotatable assembly, a drive unit for rotating the rotatable assembly relative the frame around an axis of rotation, a feed inlet for supply of a liquid mixture to be separated, a first liquid outlet for discharge of a separated liquid phase and a second liquid outlet for discharge of a heavy phase having a density that is higher than said liquid phase. The rotatable assembly includes a rotor casing enclosing a separation space in which a stack of separation discs is arranged to rotate around a vertical axis of rotation. The method includes closing one of the first and second liquid outlets and restricting the flow from the other outlet; supplying feed to the feed inlet and measuring the flow to the feed inlet and the flow from the restricted outlet; comparing the flow as a function of time between feed inlet and the restricted outlet; and determining that air is trapped within the centrifugal separator if the measured flow as a function of time flow deviates between feed inlet and the restricted outlet.

A fluid separation device includes a centrifuge in which a fluid is separated into at least two components, with an interface therebetween. At least a portion of one of the separated fluid components is removed from the centrifuge and flows through a vessel. Light is reflected off of the separated fluid component in the vessel and received and analyzed to determine its main wavelength. If the main wavelength is higher than a maximum value, a target location of the interface is changed. If the main wavelength is less than the maximum value, then the location of the interface is compared to the target location. When the interface is sufficiently close to the target location, the optical density of the separated fluid component in the vessel is compared to a minimum value. If the optical density is less than the minimum value, the target location of the interface is changed.

A fluid separation device includes a centrifuge in which a fluid is separated into at least two components, with an interface therebetween. At least a portion of one of the separated fluid components is removed from the centrifuge and flows through a vessel. Light is reflected off of the separated fluid component in the vessel and received and analyzed to determine its main wavelength. If the main wavelength is higher than a maximum value, a target location of the interface is changed. If the main wavelength is less than the maximum value, then the location of the interface is compared to the target location. When the interface is sufficiently close to the target location, the optical density of the separated fluid component in the vessel is compared to a minimum value. If the optical density is less than the minimum value, the target location of the interface is changed.