centrifuge

Abstract

The present disclosure relates to a centrifuge for separating a gas-liquid mixture into a gas phase and a liquid phase. The centrifuge comprises a first separation space (6), a first separation assistant (10) arranged in the first separation space (6), a drive means (7) configured to rotate the first separation assistant (10), an inlet (16), a gas outlet (18), and a liquid outlet (20). The centrifuge further comprises a second separation space (22), a second separation assistant (24) arranged in the second separation space (22). The drive means (7) is configured to rotate the second separation assistant (24). A first passage (26) connects the inlet (16) with the first separation space (6), and a second passage (28) connects the inlet (16) with the second separation space (22). The first and second separation assistants (10, 24) are arranged along a common axis (9).

Description

[Technical Field]

[0001] The present invention relates to a centrifugal separator for separating a gas-liquid mixture into a gas phase and a liquid phase. [Background technology]

[0002] Centrifuges can be used to separate gas-liquid mixtures into gas and liquid phases. The liquid phase may contain solid particles. An example of such gas-liquid separation is separating oil and other particles from crankcase gases.

[0003] Crankcase gases are vented from the crankcase of an internal combustion engine (ICE). Instead of being vented untreated to the atmosphere, the crankcase gases can be discharged in an environmentally friendly manner. For certain types of internal combustion engines, legislation also requires that crankcase gases be disposed of in an environmentally friendly manner.

[0004] Crankcase gases may include, among other things, blow-by gases, oil, other liquid hydrocarbons, soot, and other solid combustion residues. To properly dispose of the crankcase gases, the gases are separated from the oil, soot, and other residues. The separated gases may be directed to the air intake of the internal combustion engine or may be released into the atmosphere. The oil may optionally be returned to the combustion engine's oil sump through an oil filter to remove soot and other solid residues from the oil.

[0005] Centrifuges can be used for the disposal of crankcase gas. The crankcase gas is directed into the rotor of the centrifuge, and heavy components of the crankcase gas, such as oil and soot, are separated from the purified gas phase as a liquid phase. The liquid phase is directed out of the centrifuge through a liquid outlet. The gas phase is directed out of the centrifuge through a gas outlet and can be directed to the air intake of the ICE.

[0006] One structural feature common across centrifuges configured for gas-liquid separation is that a rotor with a separation aid, for example in the form of a separation disk, is disposed within a stationary housing. That is, the rotor rotates within a stationary separation space within the housing. Separation of the gas and liquid may be parallel, i.e., both the gas and liquid move in the same direction through the rotor during separation. Alternatively, separation of the gas and liquid may be countercurrent, i.e., the gas and liquid move in opposite directions through the rotor during separation.

[0007] The structure of a liquid-liquid or liquid-solid separator differs from the aforementioned features in that it provides a fixed separation space: in a liquid-liquid or liquid-solid separator, the rotor delimits the separation space, i.e., the separation space rotates together with the separation aid. Liquid-liquid or liquid-solid separation can only be efficiently performed in countercurrent separation.

[0008] Patent Document 1 discloses a centrifugal separator for separating oil droplets from crankcase ventilation gas. The rotor includes a shaft with disks arranged one on top of the other in a disk stack. Adjacent disks define a flow gap between them. The rotor is disposed in a housing with a raw gas inlet, a purified gas outlet, and an oil outlet. The disk stack is divided axially into a first disk stack section and a second disk stack section. Gas flow flows sequentially through the two disk stack sections. The raw gas inlet opens into a radially inner region of the first disk stack section, so that during operation, gas flows in a radially outward direction. In the second disk stack section, gas flows in a radially inward direction. That is, parallel separation is performed in the first disk stack section, and countercurrent separation is performed in the second disk stack section. This arrangement of the two disk stack sections is provided to improve oil separation from gas.

[0009] In many countries, legislation regarding crankcase gas emissions from land vehicles is very strict, and therefore gas-liquid centrifuges are the standard configuration for many types of ICEs for land vehicles.

[0010] For larger ICEs than land vehicle ICEs, larger gas-liquid centrifuges are required to handle the corresponding larger flow of crankcase gases.

[0011] More generally, the greater the flow of gas-liquid mixture to be separated, the higher the separation capacity is required for separation equipment for gas-liquid mixtures.

[0012] Gas-liquid centrifuges, which have a rotor equipped with a separation aid, such as a stack of separating discs, are designed for a specific flow rate of the gas-liquid mixture. Commonly, the gas-liquid mixture is introduced at the center of the rotor and separated as it flows radially outward through the separation aid. The rotor is disposed within a housing that defines a separation space.

[0013] The increased size of centrifuges for separating gas-liquid mixtures poses certain problems.

[0014] The centrifuge for separating the gas-liquid mixture also acts as a pump to draw the gas-liquid mixture through a conduit that introduces the gas-liquid mixture into the centrifuge.

[0015] For example, if the gas-liquid mixture is crankcase gas from an ICE, the crankcase gas ventilation of the ICE should not be limited by high resistance pressure from the crankcase gas scrubbing means. Long conduits cause high pressure drops. Therefore, the centrifuge, acting as a pump, compensates for the pressure drop in the conduits leading to the centrifuge. [Prior art documents] [Patent documents]

[0016] [Patent Document 1] International Publication No. 2019 / 175079 Brochure Summary of the Invention [Problem to be solved by the invention]

[0017] Gas flow rates greater than the centrifuge's design flow rate initially cause an undesirably high pressure drop in the gas / liquid separator due to the size of the central gas passage in the rotor and the size of the gap between the rotor and the housing.

[0018] To maintain adequate pumping capacity for centrifuges designed for high flow rates, this pressure drop must be reduced or eliminated. Redesigning the dimensions of centrifuges for gas-liquid mixtures requires reducing or eliminating the pressure drop. Such designs require increasing the inner diameter of the rotor for gas-liquid mixtures. If the outer diameter of the rotor is not increased, the separation capacity decreases. Therefore, larger diameter rotors and / or longer rotors are required. Furthermore, such redesigns require larger diameter housings to increase the distance between the rotor and the housing to reduce or eliminate the pressure drop. Such an increased distance between the rotor and the housing increases the risk of remixing of the separated liquid phase with the purified gas phase before the separated liquid phase is deposited on the inner surface of the housing. Therefore, redesigns to increase flow rates at low pressure drops lead to at least larger diameter housings for centrifuges. [Means for solving the problem]

[0019] It would be advantageous to achieve a centrifuge that is entirely configured to handle large flow rates of gas-liquid mixtures. In particular, it is desirable for a gas-liquid mixture centrifuge to be designed in such a way that it is possible to handle large flow rates of gas-liquid mixtures while having small dimensions, at least in the radial direction of the centrifuge axis. In order to better address one or more of these concerns, a centrifuge is provided having the features defined in the independent claims.

[0020] According to an aspect of the present invention, there is provided a centrifuge for separating a gas-liquid mixture into a gas phase and a liquid phase. The centrifuge includes a housing, a first separation space at least partially defined by the housing, a first separation aid disposed within the first separation space for separating the liquid phase from the gas phase, a drive means configured to rotate the first separation aid, an inlet for the gas-liquid mixture, a gas outlet for the separated gas phase, a liquid outlet for the separated liquid phase, a second separation space at least partially defined by the housing, and a second separation aid disposed within the second separation space for separating the liquid phase from the gas phase. The drive means is configured to rotate the second separation aid. A first passage connects the inlet with the first separation space, and a second passage connects the inlet with the second separation space. The first and second separation aids are further arranged along a common axis.

[0021] The drive means may be used to rotate both the first and second separation assistants. As an example, the drive means may be used to rotate both the first and second separation assistants about a common axis of rotation.

[0022] The first and second separation aids may be formed in sequence along the same common axis of rotation.

[0023] Because the centrifuge housing separates the first and second separation spaces and includes first and second separation aids, respectively, within the first and second separation spaces, and because the first passage connects the inlet to the first separation space and the second passage connects the inlet to the second separation space, the centrifuge is configured to distribute the incoming gas-liquid mixture between the two separation sections of the centrifuge. Therefore, only a portion of the total flow rate of the gas-liquid mixture flows through each of the first and second separation spaces and the separation aids. This results in a relatively low overall pressure drop within the centrifuge, particularly in the small radial dimensions of the first and second separation aids.

[0024] More specifically, the present invention is realized by dividing the flow of a gas-liquid mixture between two parallel flow paths through a centrifuge, so that the pressure drop affecting the gas-liquid mixture and the separated gas phase is reduced as it passes through the separator. More specifically, the flow rate in each flow path is reduced, for example, to half the incoming flow rate. According to the basic pipe fluid flow rate formula, gas / gas phase pressure drop, for turbulent flow, is approximately proportional to the square of the gas velocity, i.e., the ratio of flow rate to cross-sectional area, so it can be understood that doubling the cross-sectional area using two separation aids can reduce pressure drop by a factor of four. Thus, a centrifuge can be compactly sized while still achieving a lower pressure drop at a nominal flow rate through the centrifuge.

[0025] For example, when a centrifuge is used to separate a liquid phase from a gas-liquid mixture in the form of crankcase gas, a low pressure drop can be advantageous, as it translates into a low resistance pressure for ventilation of the crankcase of an associated internal combustion engine, or ICE.

[0026] Thus, a centrifuge may be provided for cleaning crankcase gases from an ICE, which may be, for example, a large diesel engine configured for propelling a ship or for driving a generator in a power plant.

[0027] Crankcase gases, also referred to as blow-by gases, may be vented from the crankcase of an ICE through a crankcase gas ventilation system, of which a centrifuge may form part.

[0028] Crankcase gases are generated when high pressure within the cylinders of the ICE pushes some of the combustion gases and liquid and solid residue past the piston rings down into the crankcase of the ICE. If not vented, the increased pressure within the crankcase can cause engine oil to leak outside the ICE, and the liquid and solid residue can contaminate and / or dilute the engine oil.

[0029] Thus, the gas-liquid mixture may be crankcase gas, and the centrifuge may be configured to separate heavier components of the crankcase gas, such as oil, other liquid hydrocarbons, soot, and other solid combustion residues, from the crankcase gas as a liquid phase.

[0030] However, centrifuges may alternatively be used in other gas-liquid separation applications, such as separating metal cutting cooling liquid mist.

[0031] In operation of the centrifuge, the gas-liquid mixture is directed through the inlet and the first and second passages into the first and second separation spaces and the first and second separation aids.

[0032] Thus, during use of the centrifuge, the flow of the gas-liquid mixture through the inlet is split into two parallel flow paths within the centrifuge: a first flow path into the first separation aid and first separation space, and a second flow path into the second separation aid and second separation space.

[0033] The first separation aid and the first separation space are approximately the same size and structure as the second separation aid and the second separation space, and in this configuration, the two parallel flow paths provide approximately the same resistance, and the first and second flow paths have the same flow rate.

[0034] The gas-liquid mixture can enter each separation assistant from its center. When the first and second separation assistants rotate, the liquid and additionally heavy components such as particles are deposited on the radially inward-facing and / or forward-facing (in the direction of rotation) surfaces of the separation assistants. The heavy components are thus separated and form droplets that flow along these surfaces. At the outer periphery of each separation assistant, the droplets are propelled against the inner wall surfaces that delimit the individual separation spaces. The droplets form a separated liquid phase that flows along the inner wall surfaces to the liquid outlet where it is guided to the outside of the centrifuge. The purified gas, i.e., the gas phase, from which all or almost all heavy components of the gas-liquid mixture have been removed, is guided to the outside of the centrifuge through the gas outlet.

[0035] Each of the first and second separation assistants has a rotation axis about which the respective separation assistant is rotated. An axial direction extends along each rotation axis, and a radial direction extends perpendicular to each rotation axis. A central portion of the separation assistant is closer to the rotation axis than a peripheral portion of the separation assistant. A circumferential direction extends around the rotation axis and / or around the separation assistant.

[0036] Each of the first and second separation aids forms a rotor or a main part of a rotor that is driven by a drive means.

[0037] Each separation aid may be rotationally symmetric.

[0038] The first and second separation aids ensure consistent separation of the liquid from the gas-liquid mixture. More specifically, the separation aids include a plurality of separation elements that improve separation of heavy components from the gas-liquid mixture. Such separation elements can be, for example, axially extending blades oriented radially from the rotor shaft or stacked frustoconical separation disks. As the rotor rotates, the heavy components are forced against the faces of the separation elements, where they form droplets and move along the separation elements toward the periphery of each separation aid.

[0039] The centrifuge housing is stationary relative to, for example, the ICE, whose crankcase gases are purified by the centrifuge.

[0040] The first and second separation assistants are arranged to rotate relative to the housing when the centrifuge is in use, and therefore the housing is stationary relative to the first and second separation assistants when the centrifuge is in use, and therefore the first and second separation spaces are also stationary relative to the housing when the centrifuge is in use.

[0041] When the centrifuge is in use, the rotating first and second separation aids accelerate the gas-liquid mixture in the circumferential direction. The separated liquid and gas phases rotate within the separation aids. Within the first and second separation spaces between each separation aid and the inner wall surface, the gas phase continues to flow in the circumferential direction at various rates and toward the gas outlet.

[0042] According to embodiments, the centrifuge may be configured to separate the gas-liquid mixture into gas and liquid phases by parallel separation, i.e., the separated phases move in the same direction, radially outward, through respective first and second separation aids.

[0043] More specifically, the centrifuge may be configured to separate the gas-liquid mixture into a gas phase and a liquid phase by parallel separation in each of the first and second separation aids.

[0044] As mentioned above, the liquid phase can move from the center of each separation aid towards their periphery, as can the other separated phase, the gas phase, which can move from the center of each separation aid towards their periphery while the heavy components are separated from the gas.

[0045] According to an embodiment, the inlet may be disposed between the first and second separation spaces. In this manner, the gas-liquid mixture may be introduced into the centrifuge from the center. Therefore, the first and second passages leading to the first and second separation spaces have approximately the same length, which promotes even distribution of the gas-liquid mixture between the first and second separation spaces.

[0046] According to an embodiment, the first and second passages may extend in opposite directions from the inlet, in this manner the gas-liquid mixture may be guided in opposite directions from the inlet to the respective first and second separation aids and separation spaces.

[0047] According to an embodiment, the radially outer portions of the first and second separation spaces may be in fluid communication with the gas outlet, in this manner the gas outlet may be provided as a common gas outlet for both the first and second separation spaces.

[0048] According to an embodiment, the radially outer portions of the first and second separation spaces may be in fluid communication with the liquid outlet, in this manner the liquid outlet may be provided as a common liquid outlet for both the first and second separation spaces.

[0049] According to an embodiment, the first and second separation aids may be arranged along a common axis. In this manner, the first and second separation aids may be aligned along a common axis. Thus, the aforementioned provisions regarding the compact radial dimensions of the centrifuge may be utilized to achieve a relatively small diameter centrifuge.

[0050] According to an embodiment, in the use position of the centrifuge, the common axis may extend substantially horizontally. In this manner, gravity equally affects the flow of the gas-liquid mixture and the separated phases in the first and second separation spaces. Therefore, the flow conditions in the first and second separation spaces may be substantially similar.

[0051] According to an embodiment, the drive means may comprise a rotor shaft extending along a common axis through the first and second separation spaces. The first and second separation aids may be connected to the rotor shaft. In this manner, the first and second separation aids may be conveniently rotated through the common axis and thus through a common drive unit connected to the rotor shaft.

[0052] Further features and advantages of the present invention will become apparent from a review of the appended claims and the following detailed description.

[0053] Various aspects and / or embodiments of the present invention, particularly its features and advantages, will be readily understood from the following detailed description and the exemplary embodiments described in the accompanying drawings. [Brief explanation of the drawings]

[0054] [Figure 1] FIG. 1 is a schematic diagram of a centrifuge according to an embodiment. [Figure 2a] FIG. 1 is a schematic diagram illustrating a cross section through a centrifuge according to an embodiment. [Figure 2b] FIG. 1 is a schematic diagram illustrating a cross section through a centrifuge according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0055] Aspects and / or embodiments of the present invention will now be more fully described. Like numbers refer to like elements throughout. Well-known functions or constructions need not be described in detail for the sake of brevity and / or clarity.

[0056] FIG. 1 is a schematic view of a centrifuge 2 according to an embodiment.

[0057] The centrifuge 2 is configured to separate a gas-liquid mixture into a gas phase and a liquid phase, which may be crankcase gas from an internal combustion engine or a gas-liquid mixture from a metal cutting machine that uses a coolant.

[0058] The centrifuge 2 includes a housing 4 that at least partially separates a first separation space and a second separation space therein. The first separation aid is disposed within the first separation space, and the second separation aid is disposed within the second separation space. The housing 4 can be formed from one or more parts.

[0059] The centrifuge 2 comprises a drive means 7 configured to rotate the first and second separation aids about a common axis 9 .

[0060] In the illustrated embodiment, the drive means 7 comprises a drive unit in the form of one electric motor arranged to rotate the first and second separating aids. In an alternative embodiment, the drive means may comprise two separate electric motors, one electric motor capable of rotating each of the first and second separating aids about a common axis or about separate axes.

[0061] As an alternative to one or more electric motors, the drive means may comprise one or more drive units such as air motors, hydraulic motors, turbine wheels, gear wheels, pulleys, belt drives, and the like.

[0062] The centrifuge 2 further comprises an inlet 16 for the gas-liquid mixture, a gas outlet 18 for the separated gas phase, and a liquid outlet 20 for the separated liquid phase.

[0063] 2a and 2b show schematic cross sections through a centrifuge according to an embodiment, the cross sections extending perpendicular to each other. In the use position of the centrifuge 2, the cross section in FIG. 2a extends in a horizontal plane, and the cross section in FIG. 2b extends in a vertical plane.

[0064] Again, the centrifuge 2 is configured to separate the gas-liquid mixture into a gas phase and a liquid phase. The centrifuge 2 may be similar to the centrifuge 2 previously discussed with reference to Figure 1. Again, the gas-liquid mixture may be crankcase gases from an internal combustion engine or mist from a metal cutting machine that uses a coolant.

[0065] Again, the centrifuge 2 comprises a housing 4, within which a first separation space 6 is at least partially defined, in which a first separation aid 10 for separating a liquid phase from a gas phase is arranged, and within which a second separation space 22 is at least partially defined, in which a second separation aid 24 for separating a liquid phase from a gas phase is arranged.

[0066] The housing 4 may be in the form of one or more parts. For example, the housing 4 may have a circumferentially extending first inner wall surface 34, which partially bounds the first separation space 6. Similarly, the housing 4 may have a circumferentially extending second inner wall surface 36, which partially bounds the second separation space 22.

[0067] More specifically, the housing 4 may include circumferential inner wall surfaces 34, 36 that receive the liquid phase. The circumferential inner wall surfaces 34, 36 are circumferential in the sense that they extend circumferentially around the respective first and second separation spaces 6, 22. The inner wall surfaces 34, 36 are configured to receive droplets of the separated liquid phase thereon and are therefore liquid phase-receiving walls.

[0068] In other words, the circumferentially extending inner wall surfaces 34 , 36 of the housing 4 may form receiving surfaces for the separate liquid phases in the first and second separation spaces 6 , 22 .

[0069] In the illustrated embodiment, the first and second separation spaces 6, 22 are each further separated in the axial direction by an axial end disk 5, 5' connected to the rotor shaft 8 of the centrifuge 2. Alternatively or additionally, the first and second separation spaces 6, 22 may each be separated in the axial direction by a portion of the housing 4.

[0070] The centrifuge 2 further comprises a drive means 7 configured to rotate the first separation assistant 10 and the second separation assistant 24 .

[0071] The drive means 7 may comprise at least a first drive unit 11 configured to rotate the first separation aid 10 .

[0072] In the illustrated embodiment, the drive means 7 is configured to rotate the first and second separation auxiliaries 10, 24 about a common axis 9. Thus, the first drive unit 11 may be configured to rotate the first and second separation auxiliaries 10, 24.

[0073] In the illustrated embodiment, the drive unit 11 is an electric motor configured to rotate the rotor shaft 8, although the drive unit 11 may be of any of the alternative types discussed above.

[0074] Therefore, the first and second separation aids 10, 24 are arranged along the common axis 9. Consequently, the first and second separation spaces 6, 22 are also aligned along the common axis 9. This means that the dimensions of the first and second separation spaces 6, 22 can contribute to determining the outer dimensions of the centrifuge 2. Therefore, the centrifuge 2 can have compact dimensions along the common axis 9.

[0075] The drive means 7 comprises a rotor shaft 8. The rotor shaft 8 extends along a common axis 9 through the first and second separation spaces 6, 22. First and second separation aids 10, 24 are connected to the rotor shaft 8.

[0076] The rotor shaft 8 may be received at its axial ends within the housing 4 in any suitable manner. In the illustrated embodiment, a bearing 13 is disposed at each end of the rotor shaft 8. The bearings 13 may be one or more of, for example, ball bearings, roller bearings, or plain bearings.

[0077] The centrifuge 2 further comprises an inlet 16 for the gas-liquid mixture, a gas outlet 18 for the separated gas phase seen in Figure 2a, and a liquid outlet 20 for the separated liquid phase seen in Figure 2b.

[0078] A first passage 26 connects the inlet 16 with the first separation space 6. A second passage 28 connects the inlet 16 with the second separation space 22.

[0079] Thus, during use of the centrifuge 2, the flow of the gas-liquid mixture through the inlet 16 is split into two parallel flow paths within the centrifuge, one along each of the first and second passages 26, 28.

[0080] Thus, upstream of the first separation space 6, the first separation space is in fluid communication with the inlet 16 through the first passage 26. Downstream of the first separation space 6, the first separation space is in fluid communication with the gas outlet 18 and the liquid outlet 20. Similarly, upstream of the second separation space 22, the second separation space is in fluid communication with the inlet 16 through the second passage. Downstream of the second separation space 22, the second separation space is in fluid communication with the gas outlet 18 and the liquid outlet 20.

[0081] More specifically, the radially outer portions of the first and second separation spaces 6, 22 are in fluid communication with the gas outlet 20. Furthermore, the radially outer portions of the first and second separation spaces 6, 22 are in fluid communication with the liquid outlet 18.

[0082] The first and second separation spaces 6,22 have a common inlet 16 and a common outlet 18,20.

[0083] The first passage 26 leads to the radial center of the first separation space 6 , and the second passage 28 leads to the radial center of the second separation space 22 .

[0084] Furthermore, the first passage 26 leads to the radial center of the first separation aid 10 , and the second passage 28 leads to the radial center of the second separation aid 24 .

[0085] The centrifuge 2 is therefore configured for parallel separation of the gas-liquid mixture into gas and liquid phases, i.e. the separated phases proceed in the same direction radially outward from the centres of the first and second separation spaces 6, 22, respectively, through the first and second separation aids 10, 24.

[0086] In the illustrated embodiment, the inlet 16 is arranged between the first separation space 6 and the second separation space 22. This means that the gas-liquid mixture can be introduced into the centrifuge 2 from the center.

[0087] Furthermore, the inlet 16 may be configured so that the flow direction of the gas-liquid mixture enters the centrifuge 2 perpendicular to the common axis 9. Thus, the first and second passages 26, 28 may be substantially identical in size and may provide the same flow resistance to the gas-liquid mixture, which may promote equal distribution of the gas-liquid mixture between the first separation space 6 and the second separation space 22.

[0088] As in the illustrated embodiment, the gas outlet 18 is also located between the first separation space 6 and the second separation space 22. This may facilitate equalizing the flow resistance in the first and second separation spaces 6, 22, thereby facilitating equal distribution of the gas-liquid mixture between the first separation space 6 and the second separation space 22.

[0089] The first and second passages 26 , 28 extend in opposite directions and are perpendicular to the inlet 16 .

[0090] As in the illustrated embodiment, the gas outlet 18 may be arranged to provide a flow direction for the gas phase leaving the centrifuge 2 perpendicular to the common axis 9. Thus, the flow paths for the gas phase from each of the first and second separation spaces 6, 22 may be approximately the same size and may provide the same resistance to the gas phase. This may promote equal distribution of the gas-liquid mixture between the first separation space 6 and the second separation space 22.

[0091] In the use position of the centrifuge 2, the common axis 9 may extend substantially horizontally, as shown in Figure 2b. In this manner, gravity equally influences the flow of the gas-liquid mixture and the separated phases into, through and out of the first and second separation spaces 6, 22, respectively.

[0092] In the use position of the centrifuge 2, as shown in Figure 2b, the liquid outlet 20 may be located at the bottom of the centrifuge 2. In this manner, the liquid phases separated in the first and second separation spaces 6, 22 may be at least partially conveyed by gravity towards and / or through the liquid outlet 20.

[0093] The flow of the gas-liquid mixture, gas phase, and liquid phase through the centrifuge 2 is indicated by arrows in Figures 2a and 2b.

[0094] Each of the first and second separation aids 10, 24 may comprise a stack 30, 30' of separation discs 32, 32'. In this manner, efficient separation of the gas-liquid mixture may be provided by each of the first and second separation aids 10, 24.

[0095] Each of the separating discs 32, 32' may have a frustoconical shape. Spaces are formed between the separating discs 32, 32' in each stack 30, 30', into which the gas-liquid mixture is guided from the center of each stack 30, 30'.

[0096] The gas-liquid mixture moves from the inner periphery to the outer periphery of the discs 32, 32' while being separated into liquid and gas phases as the individual stacks 30, 30' rotate. In Figures 2a and 2b, only some of the separating discs 32, 32' are shown.

[0097] By way of example only, each stack 30, 30' of separating discs 32, 32' may comprise more than 50 separating discs, for example up to 100 separating discs, up to 200 separating discs or more.

[0098] In the illustrated embodiment, the frustoconical separating disks 32, 32' are stacked with their large diameter ends facing axially outward within the individual stacks 30, 30'. In an alternative embodiment, the frustoconical separating disks may be stacked with their large diameter ends facing radially inward within the individual stacks.

[0099] The housing 4 is arranged stationary relative to the first and second separation aids 10, 24. That is, the first and second separation aids 10, 24 are arranged to rotate relative to the housing 4.

[0100] The housing 4 may also be stationary relative to a larger structure, such as an ICE, that produces the gas-liquid mixture to be separated in the centrifuge 2 .

[0101] It should be understood that the foregoing illustrates examples of various embodiments, and that the present invention is defined solely by the appended claims. Those skilled in the art will appreciate that the exemplary embodiments may be modified and that various features of the exemplary embodiments may be combined to create embodiments other than those individually described without departing from the invention as defined by the appended claims. [Explanation of symbols]

[0102] 2. Centrifuge 4. Housing 5, 5´ Shaft end disc 7. Driving means 8 Rotor shaft 9...Common axis 10 First separation aid 11 First drive unit 13 Bearings 16...Entrance 18 Gas outlet 20...liquid outlet 22 Second Separation Space 24 Second separation aid 26 First Passage 28 Second Passage 30, 30´ stack 32, 32´ Separation disc 34 First inner wall surface 36 Second inner wall surface

Claims

1. A centrifuge (2) for separating a gas-liquid mixture into a gas phase and a liquid phase, the centrifuge (2) comprising: a housing (4); a first separation space (6) at least partially bounded by the housing (4); a first separation aid (10) disposed in the first separation space (6) for separating the liquid phase from the gas phase; a drive means (7) configured to rotate the first separation aid (10); an inlet (16) for said gas-liquid mixture; a gas outlet (18) for the separated gas phase; a liquid outlet (20) for the separated liquid phase; a second separation space (22) at least partially bounded by said housing (4); a second separation aid (24) disposed in the second separation space (22) for separating the liquid phase from the gas phase; Equipped with the drive means (7) is configured to rotate the second separation assistant (24); a first passage (26) connecting the inlet (16) with the first separation space (22); a second passage (28) connecting the inlet (16) with the second separation space (22); A centrifuge (2), wherein the first and second separation aids (10, 24) are arranged along a common axis (9).

2. 2. The centrifuge of claim 1, wherein the inlet is located between the first separation space (6) and the second separation space (22).

3. 2. The centrifuge of claim 1, wherein radially outer portions of the first and second separation spaces (6, 22) are in fluid communication with the gas outlet (18).

4. 2. The centrifuge of claim 1, wherein radially outer portions of the first and second separation spaces (6, 22) are in fluid communication with the liquid outlet (20).

5. 2. A centrifuge according to claim 1, wherein in the position of use of the centrifuge (2), the common axis (9) extends substantially horizontally.

6. 6. The centrifuge of claim 5, wherein the drive means (7) comprises a rotor shaft (8) extending along the common axis (9) through the first and second separation spaces (6, 22), and the first and second separation aids are connected to the rotor shaft (8).

7. 2. The centrifuge of claim 1, wherein the inlet (16) is arranged to provide a flow direction of the gas-liquid mixture entering the centrifuge (2) perpendicular to the common axis (9).

8. 2. The centrifuge of claim 1, wherein the gas outlet (18) is arranged to provide a flow direction of the gas phase leaving the centrifuge (2) perpendicular to the common axis (9).

9. 2. The centrifuge according to claim 1, wherein the drive means (7) comprises at least a first drive unit (11) configured to rotate the first separation aid (10).

10. 2. The centrifuge according to claim 1, wherein in the position of use of the centrifuge (2), the liquid outlet (20) is located in the lower part of the centrifuge (2).

11. 2. The centrifuge of claim 1, wherein each of the first and second separation aids (10, 24) comprises a stack (30, 30') of separation discs (32, 32').

12. 2. The centrifuge according to claim 1, wherein the first passage (26) leads to a radial center of the first separation space (6), and the second passage (28) leads to a radial center of the second separation space (22).

13. 2. The centrifuge of claim 1, wherein the centrifuge (2) is configured to separate the gas-liquid mixture into a gas phase and a liquid phase by parallel separation.

14. The centrifugal separator according to any one of claims 1 to 13, wherein the housing (4) is arranged so as to be stationary relative to the first and second separation aids (10, 24).

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