Abstract: The present invention concerns a centrifugal separator comprising a rotor, which forms an inlet (12) for a liquid mixture, a separation chamber (5), connected to the inlet (12), for separation of components in a liquid formed mixture and a discharge chamber (10). The discharge chamber is delimited by two axially separated end walls (12, 13) and a circumferential wall (14) extending between these and has an inlet (11, 11a) connected to the separation chamber (5), an outlet in a discharge device (17) arranged in the discharge chamber (10), and means, which together with parts of the inner surfaces of the discharge chamber (10) are arranged, during operation of the rotor, to entrain into rotation a component present in the discharge chamber (10) so that this forms a rotating liquid body. This liquid body has a radially inwards directed, essentially cylindrical, free liquid surface radially inside the circumferential wall (14).

Abstract: In connection with reduction of the pressure of newly produced oil, i.e. a mixture of hydrocarbon compounds, this conventionally is performed stepwise, a momentary pressure drop occurring at each stage.According to the invention it is suggested that oil is caused to flow radially inward in a chamber (12), which is formed by a rotating vessel (1) and which is only partly filled with rotating oil, whereby the pressure drop in the oil can occur relatively slowly. A free liquid surface is maintained in the chamber (12), and a certain gas pressure is maintained in the liquid free part thereof, while evaporated hydrocarbon compounds are removed through a central gas outlet (18).

Abstract: The invention concerns a centrifugal separator with a rotor (15), in which a flexible member (28), e.g. a hose, extends a distance along the periphery of the rotor. The hose defines two parallel channels (29, 30), which form a separation chamber in the rotor and extend from the peripheral part of the rotor towards the rotor center; from there axially out of the rotor (15) at one axially directed side thereof, around the rotor to its opposite side and to a point (27) aligned with the rotor axis (C). During the operation of the rotor the hose may be rotated intermittently around its longitudinal axis relative to the rotor body, so that the radially inner and outer walls of the separation chamber are changing places.

Abstract: In a centrifuge rotor for separation of two liquids having different densities from a mixture thereof a stack of conical separation discs (21) is arranged in the separation chamber (13) with the base portions of the separation discs turned towards one end and with the apex portions of the separation discs turned towards the other end of the separation chamber. According to the invention the separation chamber (13) has an inlet for mixture situated at the end, towards which the separation discs turn their apex portions, and an outlet for separated relatively heavy liquid situated at the opposite end. The inlet for liquid mixture as well as both outlets for the separated liquids are situated at the same axial end wall of the centrifuge rotor.

Abstract: In a centrifugal rotor an annular slide (5) exposes its one side towards a separation chamber (7) and its opposite side towards an annular chamber (9). The slide (5) can be moved axially by radial displacement of the free liquid surface of liquid bodies in said chambers (7, 9).According to the invention a radial displacement of a free liquid surface in said annular chamber (9) is accomplished without liquid being discharged from the same. Instead an axial movable additional slide (6) is used, which has an axial directed surface exposed into the annular chamber (9). By means of the additional slide liquid can be displaced in the annular chamber (9) radially outwards and inwards.

Abstract: A liquid separator has a centrifuge rotor (1) with a set of conical separation discs (21) arranged coaxially in the separation chamber (13). The inlet of the separation chamber is formed as inlet passages (20) which extend radially outwards from a central inlet chamber (16) in the rotor, along that end wall of the separation chamber, towards which the apex ends of the separation discs face. The inlet passages (20) are formed between that end wall and a partition member (18, 19) situated between the rotor end wall and the separation discs (21). The outlet of the separation chamber (13) for separated liquid is formed by a number of channels (22) through the partition member (18, 19) and aligned channels through tubular members (23) bridging said inlet passages (20).

Abstract: In the rotor of a centrifugal separator a stack of conical separation discs (4) is arranged concentric with the rotor axis. The rotor has an inlet for a dispersion and an outlet for liquid having been freed from a substance dispersed therein. In each space between adjacent separation discs (4) the disc surface from which the dispersed substance moves away as a consequence of centrifugal force during rotor operation has flow influencing members, whereas the surface of the other separation disc, situated opposite to said members, is substantially smooth. The relation (L/H) where L is the distance between adjacent flow influencing members and H is the distance between the separation discs, and the relation (1/H) where 1 is the extension of each flow influencing member along the disc surface and H is the distance between the separation discs, are larger than zero but less than 2.

Abstract: In a previously known centrifugal separator the separation chamber (4) of the centrifuge rotor has an inlet (9) for a mixture of two liquids and relatively heavy solids, a central outlet (23a) for separated light liquid and a periphery outlet (12) for separated solids. A third outlet (35) from the separation chamber (4), situated radially between the first said two outlets (23a, 12), communicates with a recirculation channel, which extends partly through a stationary structure and through which liquid may be conducted from the separation chamber (4) through a sensing device (38) and back to said inlet (9) for mixture. The sensing device (38) is arranged to initiate opening of the periphery outlet (12), when a certain amount of heavy liquid has been separated in the separation chamber (4). A throttle is arranged for limiting of the flow through the recirculation channel.

Abstract: A centrifugal separator comprises a rotor having two separate coaxial rotor parts, means for axially interlocking these parts, and means arranged for discharging liquid from the separation chamber of the rotor so that the liquid pressure in the separation chamber varies. The separator is specifically characterized in that one of the rotor parts comprises two separate coaxial walls, an inner wall and an outer wall, that the inner wall is supported axially against the other rotor part, that the axially interlocking means connects the outer wall with the other rotor part, that a space is formed between the two walls, and that means are arranged to provide a force of substantially constant magnitude in the space between the walls during operation of the separator, which force acts to axially separate the walls.

Abstract: The present invention concerns a method of sensing and indicating errors in a dosing circuit, in which a pumping device (1) pumps a fluid via a conduit system out to at least one dosing device (3) located nearby a dosing place. The dosing device (3) measures and discharges intermittently a predetermined volume of the fluid through a pressure controlled non-return valve (16) to the dosing place, when the pressure in the conduit system is increased from a low pressure to a high pressure during a certain limited time.

Abstract: In a centrifugal separator a flexible member for the transport of liquid to or from a centrifuge rotor is arranged to rotate around a rotating rotor in the same direction as the rotor but with only half of its rotational speed. By such rotation the flexible member may be firmly connected with both the rotor and a stationary member without being twisted. According to the invention the flexible member has a high torsional stiffness, good tensile strength and an outside having good wear resistance. The casing comprises interplaited threads which may be metal or plastic, some of which extend helically with a certain pitch around the flexible member and others of which extend helically with an opposite pitch around the member. The interplaiting of the threads is such that the casing per se is axially compressible and expandable under radial expansion and compression, respectively. As mounted, the casing is axially expanded so that through radial compression it is in frictional engagement with the flexible member.

Abstract: In connection with recirculation of separated sludge to the separation chamber of a centrifuge separator there are normally flow restricting nozzles in the sludge outlets of the separation chamber. Only after all separated sludge has passed through these nozzles it is divided into one discharge flow and one recirculation flow.The invention concerns a centrifugal separator with a recirculation circuit (27, 28, 33, 39, 41, 43, 32, 30, 29) for separated sludge, which is completely free of flow restricting nozzles. The amount of separated sludge, that is allowed to leave the centrifugal separator through the outlet conduit (39) without being recirculated, is determined by setting of valves (22, 40) in the stationary outlet conduits (21, 39) for sludge and clarified liquid, respectively.

Abstract: The invention resides in the provision of a sludge recirculation controlled in this manner within the centrifuge rotor itself. For this reason there has been arranged centrally in the rotor, apart from a previously known reception chamber (10) for separated sludge, a recirculation chamber (14) to which sludge is transferred from the reception chamber (10). An overflow outlet (15) maintains a free liquid surface in the recirculation chamber (14) at a predetermined radial level. Recirculation channels (16), which are formed so that the flow therethrough will automatically be controlled depending upon the viscosity of the separated sludge, will conduct such sludge from the recirculation chamber (14) back to the radially outermost parts of the separation chamber (5).

Abstract: In a centrifuge having a rotor, an inlet structure has a stack of annular discs and a conduit supplying liquid to a receiving chamber formed centrally in the disc stack. The liquid mixture to be separated is caused to flow in thin layers in the passages between the discs, and by friction with the discs is accelerated to the rotational speed of the rotor. Liquid is supplied to the receiving chamber in such a way that a continuous liquid phase is maintained between the mixture in the supply conduit and in the receiving chamber.

Abstract: In a centrifugal separator for instance for purifying oil from water and solids there is a central outlet for separated water, comprising an overflow outlet maintaining a free water surface at a certain level in the door. According to the present invention this central outlet may be closed by means of an axially movable slide (23), which is rotatable together with the rotor. The rotor also has a further overflow outlet (22a) situated radially inside said predetermined level (20) such that upon supply of a so called displacement liquid to the rotor--in connection with the opening of periphery outlets (21) from the separation chamber for discharge of separated solids--separated water cannot leave the rotor through its outlet (12, 15) for separated oil.

Abstract: A centrifugal separator has a rotor with an inlet device comprising means forming a receiving chamber that surrounds a stationary inlet tube extending into the rotor. The inlet tube opens into a receiving compartment of the receiving chamber. The receiving chamber also has an induction compartment which surrounds the inlet tube at some distance from its opening.A deflecting member separates the receiving compartment from the induction compartment and leaves a passage between itself and the inlet tube. Induction members connected with the rotor are operable to induce liquid rotation in the induction chamber radially outside the level of said passage between the deflecting member and the inlet tube, whereas no substantial induction of rotation should take place in the receiving compartment.

Abstract: In a centrifuge rotor, the separation chamber (21) of which contains a set of conical separation discs (10), these are guided radially by means of guiding means (11) extending axially through the discs. At their ends, the guiding means (11) are fixed relative to the rotor body (1,2) in its periphery direction and radially. The rotor body has an upper part (1) and a lower part (2), which are held axially together at their peripheral portions. A distributor has a base portion (7) on which the separation discs (10) rest, and a neck portion (6) which extends centrally up through the disc set. The distributor is radially guided relative to the lower part and the upper part, respectively, of the rotor body. Cylindrical guiding surfaces (9) are present between the neck portion (6) and the upper rotor part (1) and, possibly, also between the base portion (7) and the lower rotor part (2).

Abstract: The present invention relates to a centrifugal separator of the kind comprising a rotor (1), which is supported by a vertical driving shaft (2), a stationary casing (3), which surrounds the rotor (1) and has a bottom opening (5) through which the driving shaft (2) extends, a frame (4) which supports the casing (3) and is arranged to support radially in a resilient manner a radial bearing (6) for the driving shaft (2), and a mechanical seal with two sealing rings abutting axially against each other, one rotatable (11) and one non-rotatable (13), to seal the interior of the casing (3) from connection with the space surrounding the radial bearing (6) via the opening (5) in the bottom of the casing (3).

Abstract: A centrifugal rotor has (a) an axially movable primary slide (5) for closing or opening peripheral outlets (11) and bordering a closing chamber (14) having inlet (15) and outlet (16) for a closing liquid, and (b) an axially movable secondary slide (20) for allowing or stopping flow through said closing liquid outlet (16), the secondary slide (20) having opposite sides bordering an opening chamber (22) and a closing chamber (21). An axially movable part is located radially outside said closing liquid outlet (16) and forms a partition (12) between the closing chambers (14 and 21) of the primary and secondary slides; the secondary slide's closing chamber (21) is closed radially inwards by an annular seal (24) between the secondary slide (20) and part (12a) of said partition (12); and the secondary slide (20) when opening uncovers an annular opening for passage of a closing liquid from the primary slide's closing chamber (14) to the secondary slide's opening chamber (22).

Abstract: In order to subject a valve within the rotor of a centrifugal separator to a certain liquid pressure, the rotor being supported by a vertical drive shaft (13), a liquid surface is maintained during operation of the rotor very close to the axis of the rotor, this surface being formed within a central channel (12) through said drive shaft (13). The lower end of the drive shaft, in which the channel (12) opens axially through an orifice (31) having its surrounding edge at the desired radial level for the liquid surface, is rotated in a liquid body which is kept in a container (25) below the drive shaft (13).