Centrifugal separator

Abstract

The invention provides a centrifugal separator (1) for separating at least one liquid phase from a liquid feed mixture, comprising a fixed frame (2), a drive member (3) and a rotating part (4), where the drive member (3) is configured to rotate the rotating part (4) relative to the fixed frame (2) about an axis of rotation (X), and where the rotating part (4) comprises a centrifugal drum (5) enclosing a separation space (9a); wherein the centrifugal separator (1) further comprises a mechanical seal (30, 50) for sealing between the rotatable part (4) and the fixed frame (2) during operation, the mechanical seal (30, 50) comprising a rotatable sealing ring (31) connected to the rotatable part (4), a fixed sealing ring (32) connected to the fixed frame (2); wherein the rotatable sealing ring (31) comprises at least one first sealing surface (31a) and the fixed sealing ring (32) comprises at least one second sealing surface (32a), the sealing surfaces (31a, 32a) having a contact force with each other and forming at least one sealing interface (33) between the rotatable and fixed sealing rings (31, 32) during operation.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of centrifugal separators, and more specifically, to a seal for a centrifugal separator. BACKGROUND

[0002] Centrifugal separators are generally used to separate liquid and / or solids from a liquid or gas mixture. During operation, the fluid mixture to be separated is introduced into a rotating drum and due to the effect of centrifugal forces, heavy particles or liquids with a higher density, such as water, are collected at the periphery of the rotating drum, while liquids with a lower density are collected closer to the rotating axis. This allows the separated components to be collected, for example, by different outlets arranged at the periphery and close to the rotating axis, respectively.

[0003] The stationary inlet and outlet pipes of high-speed separators are sealed against the rotatable part of the separator. The seal can be an air-tight seal, such as a mechanical air-tight seal, which is used when the material to be separated in the centrifugal separator should not be exposed to or come into contact with the atmosphere. Thus, the air-tight seal reduces the risk of any substances in the atmosphere, such as oxygen or particles, contaminating the liquid feed or the separated phases.

[0004] There are challenges in keeping the air-tight seal tight due to influencing parameters in the surrounding environment. As an example, in brewery applications, separated yeast can penetrate into the crevices in the seal and replace the seal liquid. This results in a reduced sealing function.

[0005] The seal liquid is traditionally used to cool and lubricate the air-tight seal. The seal liquid exerts a certain pressure on the seal.

[0006] There is therefore a need in the art for an improved mechanical air-tight seal. SUMMARY

[0007] The main object of the present invention is to provide a centrifugal separator with an improved sealing function to adjust the contact force not only by the seal liquid, but also to be applicable when separating high-concentration fluids, such as liquids including yeast.

[0008] As a first aspect of the present invention, a centrifugal separator for separating at least one liquid phase from a liquid feed mixture is provided, comprising a stationary frame, a drive member and a rotatable part, wherein the drive member is configured to rotate the rotatable part relative to the stationary frame about a rotation axis (X), and wherein the rotatable part comprises a centrifugal bowl enclosing a separation space; wherein the centrifugal bowl further comprises an inlet for receiving the liquid feed mixture and at least one liquid outlet for discharging the separated liquid phase; wherein the centrifugal separator further comprises a mechanical seal for sealing between the rotatable part and the stationary frame during operation, the mechanical seal comprising a rotatable seal ring connected to the rotatable part, a stationary seal ring connected to the stationary frame; wherein the mechanical seal provides a seal between an inner region and an outer region, and wherein the inner region is located radially inside the seal rings and extends axially through the seal rings, and the outer region is arranged radially outside the seal rings; wherein the rotatable seal ring comprises at least one first sealing surface and the stationary seal ring comprises at least one second sealing surface, which sealing surfaces have a contact force between each other and form at least one sealing interface between the rotatable seal ring and the stationary seal ring during operation; and wherein the mechanical seal is arranged in the separator such that said contact force of the mechanical seal is actively dynamically adjustable in an essentially axial direction during operation.

[0009] The drive member can be a drive motor, such as an electric motor.

[0010] As used herein, the term "axially" denotes a direction parallel to the first rotation axis (X). Accordingly, relative terms such as "above", "upper", "top", "below", "lower" and "bottom" refer to relative positions along the first rotation axis (X). Correspondingly, the term "radially" denotes a direction extending radially from the first rotation axis (X). Thus, a "radially inner position" refers to a position closer to the first rotation axis (X) than a "radially outer position". A radial plane is a plane whose normal is parallel to the first rotation axis (X). An axial plane is a plane whose normal is perpendicular to the first rotation axis (X).

[0011] The separation space of the centrifugal bowl is where the liquid feed mixture is separated into at least one liquid phase which is discharged via the at least one liquid outlet. The liquid feed mixture can be separated into a liquid heavy phase which is discharged through one outlet, and a liquid light phase which is discharged through another outlet. Further, a solid or slurry phase can also be separated from the liquid feed mixture.

[0012] The mechanical seal can be a gas-tight seal, i.e. a seal which provides a gas-tight seal.

[0013] The sealing interface is the interface between the sealing surface of the rotatable sealing ring and the sealing surface of the stationary sealing member. During normal operation, the sealing interface can have an axial height of a few micrometers and can comprise a sealing liquid or a cooling liquid, which reduces the friction between the sealing surfaces. The sealing surfaces can be substantially radially aligned to have substantially the same radial extension.

[0014] That the contact force is "dynamically adjustable during operation" means that the contact force can be actively adjusted by, for example, an operator during operation to adapt to different operating conditions. As an example, the contact force can be adjusted so that the sealing surfaces of the rotatable sealing ring and the stationary sealing ring have a tight fit or a less tight fit. A tight fit means that there is a high contact force between the sealing surfaces, while there is a less tight fit when the contact force has a lower value. The contact force can be oriented mainly in the axial direction.

[0015] The first aspect of the present invention is based on the recognition that in certain applications it is advantageous to be able to adjust the contact force between the sealing rings of a mechanical seal during operation of a centrifugal separator. And the adjustment of the contact force is not only dependent on the pressure exerted by the sealing liquid. The resulting force control can be used to control the closing pressure of the mechanical seal, which in turn can greatly reduce the power consumption. And adjusting the contact force can be used to open / lift the sealing rings of the mechanical seal during operation so that the mechanical seal itself can act as an alternative outlet for the separated liquid phase.

[0016] As an example, in separators in which yeast is the solid phase to be separated, for example when the separator is used in a brewery, it is challenging to handle fluids with high concentration and high viscosity. Yeast will often infiltrate the crevices in the mechanical seal and replace the sealing liquid (such as a water film) that is needed for normal operation. However, yeast does not have the relevant properties to maintain a uniform film for sealing, so the seal will instead leak, leading to process disruption. By dynamically adjusting the contact force of the mechanical seal in the substantially axial direction, the increased downward force can counteract any upward force experienced in the mechanical seal, thereby reducing the risk of the separated yeast replacing the sealing liquid.

[0017] Thus, the inventors have found that it is advantageous to be able to adjust the force applied to the mechanical seal so that the pressure applied to the mechanical seal is at an appropriate level throughout the entire operation. The applied force can be actively dynamically adjusted during operation. "Active" means that the applied contact force can be adjusted independently of the forces experienced by the mechanical seal from the sealing liquid, the liquid feed mixture, or any separated liquid phase. "Dynamically" means that the applied contact force can be varied throughout the entire operation and thus not stationary over time during normal operation.

[0018] In an embodiment of the first aspect, the centrifugal separator further comprises a pressurizable compartment which is arranged axially relative to the sealing ring, and wherein the pressurizable compartment is arranged to transfer pressure to the stationary sealing ring such that the contact force between the sealing surfaces is actively dynamically adjustable during operation. This results in a direct control of the contact force in order to be able to adjust the contact force during operation. Furthermore, the torsion of the seal can be controlled. The pressurizable compartment can be arranged axially above the stationary sealing ring and can be a jacket capable of defining a specific pressure which can act on the stationary sealing ring.

[0019] In an embodiment of the first aspect, the liquid outlet defines an inner region and the volume outside the centrifugal drum defines an outer region. The mechanical seal can thus be an outlet seal, such as an outlet seal arranged to seal the liquid heavy phase outlet. The volume outside the centrifugal drum can be the volume under a stationary cover covering the centrifugal drum. Thereby, a seal between the separated liquid heavy phase or the separated liquid light phase and the surrounding environment can be achieved. The mechanical seal can be arranged at the top of the centrifugal drum. The pressure exerted by the pressurizable compartment on the seal can be greater than the force experienced by the mechanical seal from the inner region.

[0020] In an embodiment of the first aspect, the centrifugal drum has a first liquid outlet for discharge of a liquid heavy phase and a second liquid outlet for discharge of a liquid light phase, and wherein the second liquid outlet defines an inner region and the first liquid outlet defines an outer region. This results in a seal between the liquid heavy phase and the liquid light phase. The mechanical seal can be arranged at the top of the centrifugal drum.

[0021] In an embodiment of the first aspect, both the inner region and the outer region form part of a liquid channel, and wherein the mechanical seal is arranged such that the contact force between the sealing surfaces is dynamically adjusted to form an axial gap allowing liquid in the inner region to be discharged to the outer region through said gap. An effective cleaning of the seal can thereby be achieved. As an example, during a clean-in-place (CIP) process, liquid for cleaning can be supplied via the gap in the mechanical seal or be discharged via the gap in the mechanical seal. The axial gap formed can also be used as an alternative outlet for the liquid heavy phase or the liquid light phase.

[0022] The inner region can also be part of an inlet, i.e. the mechanical seal can form an inlet seal. The inner region can thus form part of an inlet and the outer region can for example form part of a liquid outlet or part of the outside of the centrifugal drum.

[0023] In an embodiment of the first aspect, the rotatable component includes a drive spindle having an inlet channel for supplying the liquid feed mixture to the inlet, wherein an inner region is the inlet channel and an outer region is a volume outside the drive spindle. This allows for a seal between the feed mixture at the inlet and the surrounding environment. The seal can be arranged at the lower part of the drum.

[0024] In an embodiment of the first aspect, the mechanical seal further includes a sealing fluid chamber located at the sealing interface, and wherein the centrifugal separator further includes a sealing fluid channel for supplying sealing fluid to the sealing fluid chamber. This ensures that the sealing fluid is properly supplied to the seal. The sealing fluid may be, for example, water, and may provide a liquid film at the interface, thereby reducing friction between the rotatable sealing ring and the fixed sealing ring. The sealing fluid chamber may be arranged in the fixed sealing ring, the rotatable sealing ring, or both. Alternatively, the sealing fluid chamber may be arranged radially outside the fixed sealing ring and / or the rotatable sealing ring.

[0025] Traditionally, mechanical seals utilize a sealing fluid and a reservoir (chamber) connected to it. Applying higher pressure to the sealing fluid allows the mechanical seal to open wider; applying lower pressure allows it to open to a smaller extent. This is the conventional method for adjusting the degree to which the seal is opened.

[0026] As an example, the sealing fluid passage is separate from the pressurized compartment and its connection to the pressure source. Therefore, the control of the force applied to the seal can be independent of the sealing fluid supply process; that is, the supply of the sealing fluid and the pressure applied to the seal are controlled independently.

[0027] In an embodiment of the first aspect, the sealing fluid chamber is arranged in the second sealing surface at the sealing interface and is radially located within the fixed sealing ring, such that the rotatable sealing ring and the fixed sealing ring form a double-contact seal. A double-contact seal means that the surface of the fixed sealing ring is "divided" by the sealing fluid chamber, creating an inner surface portion and an outer surface portion, i.e., defining two contact surfaces for the double-contact seal.

[0028] This results in a more uniform distribution of the sealant, which in turn leads to a longer lifespan for the seal.

[0029] In an embodiment of the first aspect, the fixed sealing ring includes a side surface angled to the second sealing surface, and a sealing fluid channel is arranged within the fixed sealing ring, including an inlet and an outlet to the fixed sealing ring, wherein the inlet and / or outlet are arranged in the side surface. By introducing and / or drawing the sealing fluid into and / or out of the fixed sealing ring in the side surface angled to the second sealing surface, sufficient space in the axial direction above the fixed sealing ring can be created for a closed pressurized compartment. Therefore, the sealing fluid can be directed toward or out of the fixed sealing ring in the radial direction. In an embodiment of the first aspect, the sealing fluid channel is arranged radially outward of the fixed sealing ring. This provides sufficient space for a pressurized compartment that can be axially arranged above the fixed sealing ring. In an embodiment of the first aspect, the sealing fluid channel is arranged axially outward of the fixed sealing ring. Thus, the sealing fluid can be directed toward or out of the fixed sealing ring in the axial direction, which can be achieved with a tight-sealed connection through the pressurized compartment. Due to the axial extension of the sealing fluid channel, the risk of deformation and twisting of the mechanical seal is greatly reduced.

[0030] In an embodiment of the first aspect, the centrifuge further includes a spring arranged in a force-transmitting connection with both the pressurized compartment and the fixed sealing ring, wherein the spring is arranged to move axially to adjust the contact force between the sealing surfaces. Depending on whether there is positive or negative pressure in the pressurized compartment, the spring can move axially downward or upward together with the fixed sealing ring. This results in the transmitted contact force being primarily axially oriented.

[0031] In an embodiment of the first aspect, the centrifugal separator further includes a pressure source connected to the pressurizable compartment. The pressure source can supply a pressurized medium or fluid to the pressurizable compartment, which can further transmit pressure to the fixed sealing ring.

[0032] As an example, the medium of the pressure source can be a gas or a liquid used to pressurize the compartment. The pressurizing medium can be air.

[0033] In an embodiment of the first aspect, the centrifuge further includes a negative pressure generator connected to the pressurizable compartment. The negative pressure generator may be a vacuum pump, allowing the contact force to be adjusted during operation. Therefore, applying negative pressure in the pressurizable compartment reduces the contact force between the sealing surfaces. Thus, the pressure acting on the fixed sealing ring in the axially upward direction can cause the sealing surfaces to separate, thereby increasing any axial clearance formed between the sealing surfaces.

[0034] As a second aspect of the invention, a method for separating at least one liquid phase from a liquid feed mixture is provided, comprising the following steps: a) Introducing the liquid feed mixture into a centrifugal separator according to a first aspect of the invention. b) Discharge at least one liquid phase from the centrifuge; and c) Dynamically adjust the contact force between the sealing surfaces of the mechanical seal during separator operation.

[0035] This aspect generally presents the same or corresponding advantages as the first aspect. The effects and features of this second aspect are generally similar to those described above in conjunction with the first aspect. The embodiments mentioned in the first aspect are generally compatible with the second aspect.

[0036] In an embodiment of the second aspect, step c) includes introducing a pressurized gas or liquid into a pressurizable compartment, the pressurizable compartment being arranged to transmit pressure to a fixed sealing ring of the mechanical seal. The pressurized gas may be air.

[0037] In an embodiment of the second aspect, step c) includes generating a negative pressure.

[0038] In an embodiment of the second aspect, step c) includes adjusting the contact force to form an axial gap between the sealing surfaces, and step b) includes draining the liquid phase through the gap.

[0039] In a second aspect embodiment, the method further includes the following steps: d) Stop the flow of the liquid feed mixture. e) Adjust the contact force to create an axial gap between the sealing surfaces; and f) Introduce the cleaning solution into the gap.

[0040] In an embodiment of the second aspect, the liquid feed mixture includes yeast. Attached Figure Description

[0041] Figure 1 A schematic diagram of a centrifugal separator is shown.

[0042] Figure 2 A schematic diagram of a centrifugal drum with an inlet and an outlet is shown.

[0043] Figure 3a A cross-section of an embodiment of the seal at the outlet is shown.

[0044] Figure 3b A cross-section of another embodiment of the seal at the outlet is shown.

[0045] Figure 4 A cross-section of another embodiment of the seal at the outlet is shown.

[0046] Figure 5 A cross-section of another embodiment of the seal at the outlet is shown.

[0047] Figure 6 A cross-section of another embodiment of the seal at the inlet is shown. Detailed Implementation

[0048] The centrifuge according to this disclosure will be further illustrated with reference to the accompanying drawings and the following description. Figure 1 and Figure 2 The centrifugal separator and the centrifugal drum of the centrifugal separator are schematically shown.

[0049] Figure 1 A cross-section of an embodiment of a centrifuge 1 is shown. The centrifuge 1 is configured to separate a heavy phase and a light phase from a liquid feed mixture. The centrifuge 1 has a rotatable component 4, including a centrifugal drum 5 and a drive shaft 4a.

[0050] The centrifuge 1 also includes a drive motor 3. This motor 3 may include, for example, a stationary element and a rotatable element, the rotatable element surrounding and connected to the main shaft 4a, such that it transmits drive torque to the main shaft 4a during operation, and thus to the centrifugal drum 5. The drive motor 3 may be an electric motor. Alternatively, the drive motor 3 may be connected to the main shaft 4a via a transmission device (such as a drive belt or similar device), and the drive motor may alternatively be directly connected to the main shaft 4a.

[0051] Centrifugal drum 5 (in) Figure 2 (As shown in more detail below) Supported by a main shaft 4a, the main shaft 4a is rotatably arranged in a fixed frame 2 about a vertical axis of rotation (X) in the bottom bearing 22 and the top bearing 21. The fixed frame 2 surrounds the centrifugal drum 5.

[0052] exist Figure 1 In the centrifuge shown, the liquid feed mixture to be separated is supplied to the centrifugal drum 5 via a drive shaft 4a at the bottom. Therefore, in this embodiment, the drive shaft 4a is a hollow shaft, through which the feed is supplied to the centrifugal drum 5. However, in other embodiments, the liquid feed mixture to be separated is supplied from the top, such as through a fixed inlet pipe extending into the centrifugal drum 5.

[0053] After separation occurs inside the centrifugal drum 5, the separated heavy phase of liquid is discharged through the fixed outlet pipe 6a, while the separated light phase of liquid is discharged through the fixed outlet pipe 7a.

[0054] Figure 2 A more detailed view of the centrifugal drum 5 of centrifugal separator 1 is shown.

[0055] The centrifugal drum 5 forms a separation space 9a within itself and a mud space 9b located radially outside the separation space 9a. In the separation space 9a, a stack 10 of separation discs is arranged coaxially about a rotation axis (X). The stack 10 is arranged to rotate together with the centrifugal drum 5 and provide efficient separation of the liquid feed mixture to at least the light and heavy phases of the liquid. Therefore, during operation, the liquid feed mixture undergoes centrifugal separation within the separation space 9a. In this embodiment, the mud space 9b is confined between the inner surface of the centrifugal drum 5 and an axially movable operating slide 16.

[0056] The disk stack 10 is arranged below the top disk 23 and is also supported by the distributor 11 at its axial lowest point. The distributor 11 includes: an annular conical base arranged to guide the liquid mixture from the central inlet 14 of the centrifugal drum 5 to a predetermined radial level in the separation space 9a; and a central neck extending upward from the base.

[0057] The centrifugal drum 5 also includes an inlet 14, which takes the form of a central inlet chamber formed within or below the distributor 11. The inlet 14 is arranged to receive the liquid feed mixture and is therefore in fluid communication with the hollow interior 4b of the main shaft 4a through which the liquid feed is supplied to the centrifugal drum 5.

[0058] Inlet 14 communicates with separation space 9a via channel 17 formed in the base of distributor 11. Channel 17 can be arranged such that the liquid mixture is conveyed to a radial level corresponding to the radial level of the cut 25 provided in the separation discs of stack 10. Cut 25 forms an axial channel within the disc stack and distributes the liquid feed mixture through the disc stack 10.

[0059] The radial outer side of the disk stack 10 is connected to the first liquid outlet chamber 6 via channel 24 so as to axially discharge the heavy phase of liquid above the top disk 23.

[0060] The radial interior of the disc stack 10 is connected to a second outlet chamber 7 for separating the light phase of the liquid feed mixture. The second outlet chamber 7 of the centrifugal drum 5 is connected to a fixed outlet pipe 7a for discharging the separated light liquid phase from the centrifugal drum 5.

[0061] Mechanical seals 30 and 50 seal the first outlet chamber 6 and the second outlet chamber 7, respectively. Another embodiment of mechanical seal 40 seals the inlet 14. The mechanical seals will be discussed further below with reference to Figures 3-6. Because they are hermetically sealed, they are often referred to as hermetically sealed seals. The inlet passage 4b ​​is also sealed at the lower end of the hollow spindle 4a, thereby preventing communication between the inlet passage 4b ​​and the surrounding environment. Figure 2 The mechanical seal at the inlet is not shown in the image.

[0062] The centrifugal drum 5 also has outlets 15 at its radially outer periphery of the mud space 9b. These outlets 15 are evenly distributed around the rotor axis (X) and arranged to intermittently discharge mud components from the liquid feed mixture. The mud components include dense particles that form the mud phase. The opening of the outlets 15 is controlled by an operating slide 16, which is driven by an operating water channel below the operating slide 16, as is known in the art. In the position shown in the figure, the operating slide 16 seals against the upper part of the centrifugal drum 5 at its outer periphery, thereby closing the mud space 9b and disconnecting it from the outlets 15 extending through the centrifugal drum 5. The centrifugal drum 5 is defined by a surrounding outer wall 13.

[0063] like Figure 1 and Figure 2 As shown, during separator operation, drive motor 3 starts the centrifugal drum 5 to rotate. The liquid feed mixture to be separated enters the separation space 9a via spindle 4a, as indicated by arrow "A". Depending on density, different phases in the liquid feed mixture are separated between the separation discs of stack 10. Heavier components, such as the heavy liquid phase and slurry phase, move radially outward between the separation discs of stack 10 into the slurry space 9b; while the lowest density phase, such as the light liquid phase, moves radially inward between the separation discs of stack 10 and is forced through the second outlet chamber 7 into the outlet pipe 7a, as indicated by arrow "C". The higher density liquid, on the other hand, is discharged via discharge channel 24 above the top disc 23 into the first outlet chamber 6 and further discharged via the fixed outlet pipe 6a, as indicated by arrow "B". Thus, during separation, an intermediate phase between the lower and higher density liquids is formed in the centrifugal drum 5, such as radially within the stack of separation discs. Solids or slurry accumulate at the periphery of the slurry space 9b and are intermittently emptied from the centrifugal drum through the open slurry outlet 15. Subsequently, the slurry and a certain amount of fluid are discharged from the separation chamber by centrifugal force, as indicated by arrow "D". However, slurry discharge can also occur continuously, in which case the slurry outlet is in the form of an open nozzle, and a certain flow rate of slurry and / or heavy phase is continuously discharged by centrifugal force.

[0064] Figure 3a A mechanical seal 30 is shown, arranged at the top of the centrifugal drum 5 and connected to the outlet chambers 6 and 7. The mechanical seal 30 includes a rotatable sealing ring 31 connected to the rotatable component 4 (see [link to documentation]). Figure 1 and 2 ) and the fixed sealing ring 32 connected to the fixed frame 2 (see Figure 1 and 2The seal is arranged to seal between an inner region iz defined by outlet chamber 6 and an outer region oz defined by volume 8 outside drum 5. The inner region is located radially inside sealing rings 31 and 32 and extends axially through sealing rings 31 and 32, while the outer region is arranged radially outside sealing rings 31 and 32. Higher density liquid (indicated by arrow "B") is discharged via the first outlet chamber 6, and lower density liquid (indicated by arrow "C") is discharged via the second outlet chamber 7. Figure 1 and Figure 2 In centrifuge 1, the liquid feed mixture to be separated is fed from the bottom. However, it should be understood that seal 30 can also be used in a top-feed separator. In this arrangement, the inlet feed mixture is supplied via channel 7, as... Figure 3a As shown, and therefore the arrow "C" will point in the opposite direction.

[0065] The rotatable sealing ring 31 has a first sealing surface 31a, which faces a second sealing surface 32a of the fixed sealing ring 32. The sealing surfaces 31a and 32a have contact force with each other. A sealing interface 33 is formed between the rotatable sealing ring 31 and the fixed sealing ring 32.

[0066] A pressurizable compartment 60 is arranged to transmit pressure to the fixed sealing ring 32. The compartment 60 is positioned above and in close contact with the fixed sealing ring 32. This achieves contact force between the sealing surfaces 31a and 32a, and the contact force can be actively and dynamically adjusted during operation. The fixed sealing ring 32 has a side surface 32b that forms an angle with the second sealing surface 32a.

[0067] A pressure source 70 is connected to the pressurized compartment 60 via a connecting line 71 leading to an inlet 61. The pressure source 70 may be arranged radially outside the pressurized compartment 60. The pressure source 70 contains a medium, which may be gas or liquid, to pressurize the compartment 60. Typically, the medium is air.

[0068] The sealing fluid chamber 90 is arranged at the second sealing surface 32a, at the sealing interface 33 and radially located within the fixed sealing ring 32, such that a double contact seal is formed by the rotatable sealing ring 31 and the fixed sealing ring 32, and wherein the chamber 90 is connected to the sealing fluid channel 80.

[0069] A sealing fluid passage 80 is arranged within a fixed sealing ring 32 and includes an inlet 81 and an outlet 82 leading to the fixed sealing ring 32, wherein the inlet and outlet are radially arranged in a side surface 32b. The inlet 81 has a connection 83 to a sealing fluid reservoir 85. Sealing fluid and its reservoir are conventionally used in mechanical seals. By applying higher pressure from the sealing fluid, the mechanical seal is opened wider; and by applying lower pressure from the sealing fluid, the mechanical seal is opened to a smaller extent.

[0070] Alternatively, the pressure source 70 can be a negative pressure generator, such that the pressurizable compartment 60 includes a vacuum. This generates a "negative" pressure, causing the resulting force to move in the opposite direction, forcing the sealing surfaces 31a and 32a apart, thereby creating a gap between the sealing surfaces 31a and 32a.

[0071] A spring 62 is arranged in compartment 60.

[0072] Figure 3b Mechanical seal 30 is shown, arranged at the top of centrifugal drum 5 to connect to outlet chambers 6, 7. In another embodiment, sealing fluid passage 80 extends axially, such that an inlet passes through pressurized compartment 60 and fixed sealing ring 32. Inlet 81 of sealing fluid passage 80 has a connection 83 to sealing fluid reservoir 85. Sealing fluid passage 80 provides a tight, sealed connection between sealing fluid reservoir 85 and fixed sealing ring 32, leaving no connection to pressurized compartment 60 or its pressure source 70.

[0073] The pressurizable compartment 60 is arranged to transmit pressure to the fixed sealing ring 32. (See also: ...) Figure 3a As described, compartment 60 is arranged above and in close contact with the fixed sealing ring 32. This creates a contact force between sealing surfaces 31a and 32a, and the contact force can be actively and dynamically adjusted during operation. The fixed sealing ring 32 has a side surface 32b that forms an angle with the second sealing surface 32a.

[0074] Figure 3b The other components are related to Figure 3a The components in [the text] correspond to those components. Furthermore, they have the same function, and therefore [are related to] [the text]. Figure 3a The description also applies to Figure 3b .

[0075] Figure 4 A mechanical seal 30 is shown for use as an outlet, such that a liquid passage is formed between sealing surfaces 31a and 32a, and is arranged to connect to outlet chambers 6 and 7 at the top of the centrifugal drum 5. (As shown in...) Figure 3a and 3bIn this configuration, a seal is arranged between an inner region iz defined by outlet chambers 6 and 7 and an outer region oz defined by a volume 8 outside the drum 5. The inner region is located radially inside and extends axially through sealing rings 31 and 32, while the outer region is arranged radially outside the sealing rings 31 and 32, wherein both the inner region iz and the outer region oz form part of a liquid passage. The higher-density liquid, indicated by arrow "B", is discharged via the first outlet chamber 6 and further discharged to the outer region through the interface between the rotatable sealing ring 31 and the fixed sealing ring 32.

[0076] The contact force between sealing surfaces 31a and 32a is dynamically adjusted to create an axial clearance that allows liquid in the inner region to flow to the outer region. The adjustment of the contact force is controlled by the pressurized compartment 60, in relation to... Figure 3a and 3b Similar to what has been discussed. Furthermore, the sealed liquid chamber 85 and its associated components have similar characteristics to those discussed above. Figure 3a The corresponding functions described.

[0077] Figure 5 A mechanical seal 50 is disclosed, arranged at the top of a centrifugal drum 5 and connected to outlet chambers 6 and 7. The seal is arranged between an inner region iz defined by outlet chamber 7 (for lower density liquids) and an outer region oz defined by outlet chamber 6 (for higher density liquids). The inner region is located radially inside sealing rings 31 and 32 and extends axially through them; while the outer region is arranged radially outside sealing rings 31 and 32. Figure 3a and 3b In the mechanical seal 50, there are a rotatable sealing ring 31 connected to the rotatable component 4 and a fixed sealing ring 32 connected to the fixed frame 2.

[0078] The rotatable sealing ring 31 has a first sealing surface 31a, which faces a second sealing surface 32a of the fixed sealing ring 32. The sealing surfaces 31a and 32a have contact force with each other. A sealing interface 33 is formed between the rotatable sealing ring 31 and the fixed sealing ring 32.

[0079] A pressurizable compartment 60 is arranged to transmit pressure to a fixed sealing ring 32. The compartment 60 is axially positioned above and in close contact with the fixed sealing ring 32. This achieves contact force between the sealing surfaces 31a and 32a, and the contact force can be dynamically adjusted during operation.

[0080] The pressure source 70 for pressurizing the compartment 60 can be arranged axially above the pressurizable compartment 60.

[0081] The sealing fluid chamber 90 is arranged at the second sealing surface 32a, at the sealing interface 33 and radially within the fixed sealing ring 32, and the chamber 90 is connected to the sealing fluid channel 80.

[0082] The sealing fluid channel 80 is arranged within the fixed sealing ring 32 and includes an inlet 81 and an outlet 82 to the fixed sealing ring 32, wherein the inlet and outlet are arranged in the axial direction.

[0083] Figure 6 A mechanical seal 40 is shown, arranged at the lower part of the centrifugal drum 5 and connected to the inlet 14. The seal is arranged between an inner region iz defined by the inlet 14 (receiving the liquid feed mixture) and an outer region oz defined by the outer volume 8 of the drum 5. As shown in the figure described above, the mechanical seal 40 includes a rotatable sealing ring 31 connected to the rotatable component 4 and a fixed sealing ring 32 connected to the fixed frame 2.

[0084] The rotatable sealing ring 31 has a first sealing surface 31a, which faces a second sealing surface 32a of the fixed sealing ring 32. The sealing surfaces 31a and 32a have contact force with each other. A sealing interface 33 is formed between the rotatable sealing ring 31 and the fixed sealing ring 32.

[0085] A pressurizable compartment 60 is arranged to transmit pressure to a fixed sealing ring 32. The compartment 60 is axially positioned below and in close contact with the fixed sealing ring 32. This achieves contact force between the sealing surfaces 31a and 32a, and the contact force can be dynamically adjusted during operation.

[0086] The pressure source 70 for the pressurized compartment 60 can be arranged axially below the pressurized compartment 60.

[0087] The sealing fluid chamber 90 is arranged at the second sealing surface 32a, at the sealing interface 33 and radially within the fixed sealing ring 32, and the chamber 90 is connected to the sealing fluid channel 80.

[0088] The sealing fluid channel 80 is arranged within the fixed sealing ring 32 and includes an inlet 81 and an outlet 82 to the fixed sealing ring 32, wherein the inlet and outlet are arranged in the axial direction.

[0089] In addition, for Figure 5 and Figure 6 The sealing fluid chamber 85 and related components of the sealing fluid have relevant information. Figure 3a The corresponding functions described.

[0090] Alternatively, the sealing fluid chamber 90 can be arranged radially outside the fixed sealing ring 32 (not shown in the figure).

[0091] This invention is not limited to the disclosed embodiments, but can be varied and modified within the scope of the claims set forth below. The invention is not limited to the type of separator shown in the figures. The term "centrifugal separator" also includes centrifugal separators with a substantially horizontally oriented axis of rotation and separators with a single liquid outlet.

Claims

1. A centrifugal separator (1) for separating at least one liquid phase from a liquid feed mixture, comprising: The components consist of a fixed frame (2), a driving component (3), and a rotating component (4). The drive member (3) is configured to rotate the rotatable component (4) about the rotation axis (X) relative to the fixed frame (2), and The rotatable component (4) includes a centrifugal drum (5) that encloses the separation space (9a); The centrifugal drum (5) further includes an inlet (14) for receiving the liquid feed mixture and at least one liquid outlet (6, 7) for discharging the separated liquid phase; The centrifuge (1) further includes mechanical seals (30, 50) for sealing the rotatable component (4) and the fixed frame (2) during operation, the mechanical seals (30, 50) comprising... A rotatable sealing ring (31) is connected to the rotatable component (4). A fixing sealing ring (32) is connected to the fixing frame (2); The mechanical seals (30, 50) provide a seal between an inner region (iz) and an outer region (oz), wherein the inner region is located radially inside the sealing rings (31, 32) and extends axially through the sealing rings (31, 32), and the outer region is arranged radially outside the sealing rings (31, 32). in, The rotatable sealing ring (31) includes at least one first sealing surface (31a), and the fixed sealing ring (32) includes at least one second sealing surface (32a). The sealing surfaces (31a, 32a) have contact forces with each other and form at least one sealing interface (33) between the rotatable sealing ring and the fixed sealing ring (31, 32) during operation; and The mechanical seals (30, 50) are arranged in the separator such that the contact force of the mechanical seals (30, 50) is actively and dynamically adjustable in the fundamental axial direction during operation.

2. The centrifuge (1) according to claim 1 further includes a pressurizable compartment (60) arranged axially relative to the sealing rings (31, 32), wherein the pressurizable compartment (60) is arranged to transmit pressure to the fixed sealing ring (32) such that the contact force between the sealing surfaces (31a, 32a) is actively and dynamically adjustable during operation.

3. The centrifuge (1) according to claim 1 or 2, wherein, The liquid outlet (6) defines the inner region (iz), and the volume (8) outside the centrifugal drum (5) defines the outer region (oz).

4. The centrifugal separator (1) according to any one of claims 1 or 2, wherein, The centrifugal drum (5) has a first liquid outlet (6) for discharging the heavy phase (B) and a second liquid outlet (7) for discharging the light phase (C), wherein the second liquid outlet (7) defines the inner region (iz) and the first liquid outlet (6) defines the outer region (oz).

5. The centrifugal separator (1) according to any one of the preceding claims, wherein, The inner region (iz) and the outer region (oz) together form part of a liquid channel, and the mechanical seal (30) is arranged such that the contact force between the sealing surfaces (31a, 32a) is dynamically adjusted to form an axial gap, thereby allowing liquid in the inner region (iz) to drain through the gap to the outer region (oz).

6. The centrifugal separator (1) according to any one of claims 1 or 2, wherein, The rotatable component (4) includes a drive spindle (4a) having an inlet channel (4b) for supplying the liquid feed mixture to the inlet (14), wherein the inner region (iz) is the inlet channel (4b) and the outer region (oz) is the volume (8) outside the drive spindle (4a).

7. The centrifugal separator (1) according to any one of the preceding claims, wherein, The mechanical seals (30, 50) further include a sealing fluid chamber (90) at the sealing interface (33), and the centrifugal separator (1) further includes a sealing fluid channel (80) for supplying sealing fluid to the sealing fluid chamber (90), and the sealing fluid channel (80) is disconnected from the pressurizable compartment (60) and its connection to the pressure source (70).

8. The centrifuge (1) according to claim 7, wherein, The sealing fluid chamber (90) is arranged in the second sealing surface (32a) at the sealing interface (33) and radially arranged within the fixed sealing ring (32), such that a double contact seal is formed by the rotatable sealing ring and the fixed sealing ring (31, 32).

9. The centrifugal separator (1) according to any one of claims 7 to 8, wherein, The fixed sealing ring (32) includes a side surface (32b) that forms an angle with the second sealing surface (32a), and wherein the sealing fluid channel (80) is arranged within the fixed sealing ring (32) and includes an inlet (81) and an outlet (82) to the fixed sealing ring (32), and wherein the inlet (81) and / or the outlet (82) are arranged in the side surface (32b).

10. The centrifuge (1) according to claim 7, wherein, The sealing fluid channel (80) is arranged radially outside the fixed sealing ring (32).

11. The centrifuge (1) according to claim 7, wherein, The sealing fluid channel (80) is arranged on the axial outside of the fixed sealing ring (32).

12. The centrifuge (1) according to any one of the preceding claims further includes a spring (62) arranged to be force-transmittingly connected to both the pressurizable compartment (60) and the fixed sealing ring (32), wherein the spring (62) is arranged to move in an axial direction to adjust the contact force between the sealing surfaces.

13. The centrifugal separator (1) according to any one of the preceding claims further includes a pressure source (70) connected to the pressurizable compartment (60).

14. The centrifugal separator (1) according to any one of the preceding claims, wherein, The medium of the pressure source (70) is a gas or liquid used to pressurize the compartment (60).

15. The centrifugal separator (1) according to any one of claims 2 to 12 further includes a negative pressure generator connected to the pressurizable compartment (60).

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