Separation system for separating liquid mixture

Abstract

The invention provides a separation system (120) comprising a centrifugal separator (100) for separating a liquid feed mixture, where the centrifugal separator (100) is arranged for separating the liquid feed mixture into at least one separated liquid phase and discharging the at least one separated liquid phase. The separation system (120) further comprises a flow measurement arrangement (90) arranged for receiving a measurement liquid selected from the liquid feed mixture and the separated liquid phase. The flow measurement arrangement comprises a first container (60) for holding a measurement liquid, a first device (61) for measuring a parameter relating to the weight of the measurement liquid contained in the first container (60), a second container (70) for holding a measurement liquid, second means (71) for measuring a parameter relating to the weight of the measurement liquid contained in the second container (70), in which the flow measurement arrangement (90) is further arranged to allow emptying of the measurement liquid of the first container (60) while filling a further container of the flow measurement arrangement (90) with a measurement liquid of the same type, and vice versa, and to allow emptying of the measurement liquid of the second container (70) while filling a further container of the flow measurement arrangement (90) with a measurement liquid of the same type. Thus, the first container (60) and the other container of the flow measuring arrangement (90) are allowed to be alternately filled with the same type of measuring liquid.

Description

Technical Field

[0001] The inventive concept relates to the field of centrifugal separators.

[0002] More particularly, it relates to separation systems and methods for measuring liquid flow to and / or from a centrifugal separator. Background Art

[0003] Centrifugal separators are generally used to separate liquids and / or solids from a liquid mixture or a gas mixture. During operation, the fluid mixture to be separated is introduced into a rotating drum, and due to centrifugal force, heavy particles or denser liquids (such as water) accumulate at the periphery of the rotating drum, while less dense liquids accumulate closer to the central rotation axis. This allows the separated fractions to be collected, for example by means of different outlets arranged at the periphery and close to the rotation axis, respectively.

[0004] The traditional way to measure the liquid flow of the separated liquid phase from a centrifugal separator is to use a flow sensor. Flow sensors are generally expensive, and it can be difficult to select a suitable flow sensor for a particular application, because flow sensors may rely on several different measurement principles, all of which have their own advantages and disadvantages. If one wants to measure different liquids with the same flow sensor, or if the temperature or liquid composition changes over time, measurement errors usually occur.

[0005] WO 2021 / 191023 discloses a system and method for determining the flow rate (such as mass flow) of a liquid phase discharged from a centrifugal separator. To this end, a container arranged downstream of any liquid outlet in the liquid outlet is used. In addition, there is a gauge for measuring the weight of the discharged liquid phase contained in the container. With such knowledge, the mass increase per period of time and therefore the flow rate of the discharged liquid phase can be calculated.

[0006] However, in such systems further improvements in measurement methods may be required. Summary of the invention

[0007] It is an object of the present invention to at least partially overcome one or more limitations of the prior art. In particular, it is an object to provide a separator and a method for determining the flow rate of a measurement liquid with an improved duty cycle during which a flow measurement can be performed.

[0008] As a first aspect of the present invention, a separation system is provided, the separation system comprising a centrifugal separator for separating a liquid feed mixture. The centrifugal separator is arranged to separate the liquid feed mixture into at least one separated liquid phase and discharge the at least one separated liquid phase. The separation system also comprises

[0009] A flow measurement arrangement arranged for receiving a measurement liquid selected from a liquid feed mixture and a separated liquid phase, wherein the flow measurement arrangement comprises

[0010] a first container for holding a measurement liquid;

[0011] first means for measuring a parameter related to the weight of a measurement liquid contained in said first container,

[0012] a second container for holding the measuring liquid,

[0013] second means for measuring a parameter related to the weight of a measurement liquid contained in said second container,

[0014] Therein, the flow measurement arrangement is further arranged to allow emptying of the first container of the flow measurement arrangement while filling a further container of the flow measurement arrangement with the same type of measurement liquid, and vice versa, thereby allowing alternating filling of the first container and the further container of the flow measurement arrangement with the same type of measurement liquid.

[0015] The centrifugal separator may be as disclosed in WO 2021 / 191023. Thus, the centrifugal separator may have a rotatable component arranged for multiple uses (such as a conventional stainless steel centrifuge barrel) or a rotatable component arranged for single use (such as a replaceable insert known from, for example, WO 2020 / 120357). Thus, in an embodiment of the first aspect, the rotatable component may comprise a replaceable separation insert and a rotatable component; the insert comprising a rotor housing and supported by the rotatable component. Such a replaceable separation insert may therefore be a preassembled insert mounted in a rotatable support for the insert. The replaceable insert may therefore be easily inserted into and removed from the rotatable support as a single unit.

[0016] According to an embodiment, such a replaceable separation insert is a single-use separation insert. Thus, the insert may be adapted for single use and be a disposable insert. The replaceable insert may thus be used to process one product batch (such as a single product batch in the pharmaceutical industry) and then be disposed of. The replaceable separation insert may comprise or consist of a polymer material.

[0017] The centrifugal separator may be arranged to separate the liquid feed mixture into two liquid phases, such as a liquid light phase and a liquid heavy phase, wherein the liquid heavy phase has a higher density than the liquid light phase. Thus, the centrifugal separator may include a single outlet for the discharged liquid phase or two outlets for the discharged liquid phase.

[0018] The flow measurement arrangement is arranged to allow emptying of a container of measurement liquid while filling a further container of the flow measurement arrangement with the same type of measurement liquid, and vice versa. This thus allows alternately filling the first container and the further container of the flow measurement arrangement with the same type of measurement liquid. In other words, the flow measurement arrangement allows alternately filling the first container and the further container of the flow measurement arrangement with one of the separated liquid phases or a liquid feed mixture.

[0019] The flow measurement arrangement of the present disclosure may be arranged for measuring the flow rate of an inlet feed mixture.

[0020] Hence, in an embodiment of the first aspect, the flow measurement arrangement is arranged upstream of the inlet of the centrifugal separator for measuring the flow rate of the liquid feed mixture. Hence, in an embodiment, the measurement liquid is the liquid feed mixture.

[0021] Additionally or alternatively, the flow measurement arrangement of the present disclosure may be arranged to measure the flow rate of the separated liquid phase from the centrifugal separator. Thus, in an embodiment of the first aspect, the flow measurement arrangement is arranged downstream of a liquid outlet of the centrifugal separator, such as downstream of a liquid outlet for discharging the separated liquid light phase and / or downstream of a liquid outlet for discharging the separated liquid heavy phase.

[0022] The flow measurement arrangement of the present disclosure may be arranged downstream of the liquid outlet of a centrifugal separator where the centrifugal separator has a single outlet for the separated liquid phase, or may be arranged downstream of one or both of the liquid outlets of a centrifugal separator having two liquid outlets for two different separated phases.

[0023] Thus, in an embodiment, the measurement liquid is a separated liquid phase, such as a separated liquid light phase or a separated liquid heavy phase.

[0024] The first container and the second container may be suspended in the first device and the second device for measuring a parameter related to the weight of the measuring liquid, respectively.The containers may be suspended in a suspension direction substantially in the vertical direction.

[0025] A first aspect of the invention is based on the insight that having more than one container for measuring the flow of a measurement liquid is an advantage because it allows the flow rate of the measurement liquid to be determined almost continuously. With only one container, it may be difficult to determine the flow rate during the emptying of the container. When using containers and load cells to measure, for example, the mass flow of the measurement liquid, more than one container, such as two containers, therefore increases the duty cycle. Thus, one container can be used for measurements when another container, such as a second container, is off-line and / or in an emptying phase. This enables a measurement duty cycle of almost 100%.

[0026] Furthermore, the flow measurement arrangement occupies a small amount of space, ie it is an advantage to use the flow measurement arrangement in applications where a reduced footprint is useful, such as in single-use processing lines for the production of biopharmaceuticals.

[0027] A single flow measurement system is arranged upstream of the inlet or downstream of one of the liquid outlets. However, the separation system may include more than one flow measurement system. A single flow measurement system may be arranged for receiving a single measurement liquid, such as a liquid feed mixture or a separated liquid phase, during a separation process.

[0028] The flow measurement arrangement of the present disclosure may include more than two containers for alternately filling and emptying with the same type of measurement liquid. Therefore, the flow measurement arrangement of the present disclosure may include additional containers and additional devices for measuring parameters related to the weight of the measurement liquid contained in such additional containers. As an example, the flow measurement arrangement may include at least three (such as at least four) containers.

[0029] In the simplest design, the flow measurement arrangement has only a first and a second container.

[0030] Thus, in an embodiment of the first aspect, the further container of the flow measurement arrangement is a second container. Thus, the flow measurement arrangement can be arranged to allow emptying of the first container of measurement liquid while filling the second container with measurement liquid, and vice versa, thereby allowing alternating filling of the first container and the second container with the same type of measurement liquid.

[0031] In the text below, the flow measurement arrangement will mainly be discussed as having only a first and a second container. However, the skilled person will understand how to adapt and use a flow measurement arrangement with more than two containers for alternately filling the first container and the further containers of the flow measurement arrangement with the same type of measurement liquid for almost continuous determination of the flow rate of the measurement liquid.

[0032] The flow rate may be determined as a mass flow rate. The mass flow rate may be calculated by determining the weight increase (Δw) of the container during a time interval (Δt) and then estimating Δw / Δt. The volume flow rate may be determined from the mass flow rate using the density of the liquid phase entering the container.

[0033] In an embodiment of the first aspect, the flow measurement arrangement comprises a conduit arrangement for conveying the measurement liquid to and from the first container and to and from the second container.

[0034] The pipes of the pipe arrangement may be polymer pipes, such as siliconized pipes. Such pipes may have a large wall thickness. The pipe arrangement is thus arranged for receiving the measurement liquid and for allowing the measurement liquid emptied from the container to be conveyed to a processing device downstream of the separation system. Thus, the pipe arrangement is in fluid contact with the liquid outlet of the centrifugal separator and may be connected to a further pipe or tube downstream of the flow measurement arrangement.

[0035] As an example, the conduit arrangement may comprise a single inlet conduit for receiving the measuring liquid to be filled in the first container and the second container.

[0036] This may allow connectability to a liquid outlet of the centrifugal separator.

[0037] Furthermore, the conduit arrangement may comprise a first valve for directing the measuring liquid in the single inlet conduit to the first container while preventing the measuring liquid from being conveyed to the second container, and vice versa.

[0038] The first valve may thus be a three-way valve.The first valve in the flow measurement arrangement may be arranged upstream of both the first container and the second container.

[0039] Furthermore, the pipeline arrangement may comprise a second valve arranged for allowing the first container to be emptied of measuring liquid while the second container is filled with measuring liquid, and a third valve arranged for allowing the second container to be emptied of measuring liquid while the first container is filled with measuring liquid.

[0040] The second valve can thus be arranged between the first valve and the first container. The third valve can be arranged between the first valve and the second container. The second valve and the third valve can also be three-way valves. The second valve and the third valve can be arranged to empty the container into a pipeline arranged downstream of the first container and the second container, respectively.

[0041] Furthermore, the conduit arrangement may comprise a single outlet conduit, which is arranged for conveying measurement liquid emptied from the first container and the second container out of the flow measurement arrangement.

[0042] A single outlet conduit may thus be arranged for conveying all of the liquid phase emptied from the vessel to downstream processing equipment.

[0043] Furthermore, the conduit arrangement may comprise a fourth valve for allowing measurement liquid emptied from said first and second containers to be conveyed out of the measurement arrangement via said single outlet conduit.

[0044] The fourth valve can therefore be arranged downstream of the first container and the second container and connected to a single outlet pipe. The fourth valve can therefore be a three-way valve. The measured liquid emptied from the first container can therefore be guided to the fourth valve via the second valve and to a single outlet pipe via the fourth valve. Similarly, the measured liquid emptied from the second container can therefore be guided to the fourth valve via the third valve and to a single outlet pipe via the fourth valve.

[0045] In an embodiment of the first aspect, the separation system further comprises a control unit for controlling the alternating filling of the first container and the second container with the same type of measuring liquid.

[0046] The control unit may thus comprise a processor and a communication interface for communicating with the first, second, third and / or fourth valves. The control unit may thus be configured to send an operation request to the first, second, third and / or fourth valves. For this purpose, the control unit may comprise a device with processing capabilities in the form of a processing unit, such as a central processing unit, configured to execute computer code instructions, which may be stored, for example, on a memory. The processing unit may alternatively be in the form of a hardware component.

[0047] In an embodiment of the first aspect, the first container and / or the second container is a flexible bag.

[0048] The first container and / or the second container may thus be a polymer bag suspended in, for example, a gauge.

[0049] The first container and / or the second container may comprise a liquid inlet and a liquid outlet. These may be separate connectors, such as separate connectors arranged at separate locations on the container. The liquid outlet may be a pipeline arranged in the liquid inlet, or vice versa.

[0050] However, in an embodiment of the first aspect, the liquid inlet is also the liquid outlet of the container. Thus, the container can be filled and emptied using the same connector for the liquid, wherein the connector serves as both the liquid inlet and outlet.

[0051] In an embodiment of the first aspect, the first container and / or the second container comprises a liquid inlet for receiving the measurement liquid and a liquid outlet for emptying the liquid phase from the container.

[0052] In an embodiment of the first aspect, the liquid inlet and / or the liquid outlet of the container is arranged in a lower part of the container.

[0053] The first and second containers may be arranged for periodic filling and emptying, and during filling of the containers and when no liquid leaves the containers, the weight gain over time may be evaluated and the liquid flow rate (eg volumetric flow or mass flow) may be determined.

[0054] In an embodiment of the first aspect, the first device for measuring a parameter related to the weight of the measuring liquid contained in the first container and / or the second device for measuring a parameter related to the weight of the measuring liquid contained in the second container is a scale, such as a hanging scale.

[0055] In an embodiment of the first aspect, the hanging direction is a vertical direction. Thus, the container can be hung in a device for measuring a parameter related to the weight of the measuring liquid in a vertical direction. The device can thus be a hanging scale, i.e. the container can be hung from the scale instead of resting on it.

[0056] The scale may include a load cell. Such a load cell may thus be a force transducer that converts a force (such as tension, compression, pressure or torque) into a measurable electrical signal. The load cell may thus be a strain gauge load cell. Such a load cell may include a body that deforms slightly when a load is applied. This in turn may cause a change in the resistance of the strain gauge, which may be measured as a voltage change proportional to the amount of weight applied.

[0057] However, the device for measuring a parameter related to the weight of the measuring liquid may also be a device for measuring a parameter proportional to the weight of the measuring liquid, such as a device for measuring the volume of the measuring liquid in a container.

[0058] The mass flow rate can be calculated by determining the weight increase (Δw) of the container during a time interval (Δt) and then estimating Δw / Δt. The volume flow rate can be determined from the mass flow rate using the density of the liquid phase entering the container.

[0059] The rest of the separation system may be as disclosed in WO 2021 / 191023.

[0060] The centrifugal separator may comprise a fixed frame, a rotatable assembly and a drive unit for rotating the rotatable assembly relative to the frame about a rotation axis (X). The centrifugal separator may further comprise a feed inlet for receiving a liquid feed mixture to be separated, at least one liquid outlet for discharging the separated liquid phase, wherein the rotatable assembly comprises a rotor housing enclosing a separation space in which separation of the liquid feed mixture occurs during operation, and wherein the separation space is arranged for receiving the liquid feed mixture from the feed inlet.

[0061] The stationary frame of the centrifugal separator is the non-rotating part and the rotatable assembly is supported within the frame, for example by means of at least one bearing, such as a ball bearing.

[0062] The centrifugal separator may further comprise a drive unit arranged to rotate the rotatable component and may comprise an electric motor or be arranged to rotate the rotatable component by a suitable transmission such as a belt or gear transmission. Thus, the drive unit may be arranged to drive the rotatable component directly or indirectly via a transmission.

[0063] The rotatable assembly includes a rotor housing in which separation occurs. The rotor housing can therefore be a centrifuge barrel. The rotor housing surrounds a separation space in which separation of a fluid mixture (such as a cell culture mixture) occurs. The rotor housing can be a non-voided rotor housing, and there is no additional outlet for the separated phase. Therefore, the non-voided rotor housing can be non-voided because it does not have any peripheral ports for discharging, for example, the sludge phase accumulated at the periphery of the separation space. However, in an embodiment, the rotor housing includes a peripheral port for discharging the separated phase intermittently or continuously from the periphery of the separation space.

[0064] The rotor housing may be arranged for multiple uses or be a replaceable insert arranged for single use.

[0065] The feed inlet is used for receiving the liquid feed mixture to be separated and for conducting the feed to the separation space.

[0066] The separation space may comprise a stack of separation discs arranged centrally around the axis of rotation.The stack may comprise frustoconical separation discs.

[0067] The separation disc may thus have a frustoconical shape, which refers to a shape having a frustum of a cone (this shape is the shape of a cone with the narrow end or tip removed). The frustoconical shape thus has an imaginary vertex, at which the tip or vertex of the corresponding conical shape is located. The axis of the frustoconical shape is axially aligned with the axis of rotation of the rotor housing without a gap. The axis of the frustoconical portion is the direction of the height of the corresponding conical shape or the direction of the axis through the vertex of the corresponding conical shape.

[0068] The separation discs may alternatively be axial discs arranged around the axis of rotation.

[0069] The separation disc may for example comprise or be of a metal material, such as stainless steel.The separation disc may also comprise or be of a plastic material.

[0070] The centrifugal separator may be arranged to separate the liquid feed mixture into at least one liquid phase, such as into at least a first and a second liquid phase. The separated liquid phases may be discharged via a first liquid outlet and a second liquid outlet. The first liquid outlet (also denoted as liquid light outlet) is used to discharge the separated liquid phase of lower density, while the second liquid outlet (also referred to as liquid heavy outlet) is used to separate a phase of higher density than the liquid phase discharged via the first liquid outlet.

[0071] The flow measurement arrangement may be arranged downstream of the first liquid outlet and / or downstream of the second liquid outlet.In an embodiment, there is a flow measurement arrangement arranged downstream of both liquid outlets.

[0072] The first container and the second container may be arranged for filling and emptying, for example in a cyclical manner.Thus, in embodiments of the first aspect, the first container and / or the second container are not storage containers for long-term storage of any separated liquid phase.

[0073] Hence, in an embodiment of the first aspect, the separation system comprises a tank for receiving the liquid phase emptied from the flow measurement arrangement.

[0074] The tank may be arranged to store the separated liquid phase for a long time. The tank may therefore have a volume greater than the volume of the first and second containers. The tank may have a volume at least five times (such as at least ten times, such as at least 25 times) the volume of the first and second containers. The tank may, for example, be stainless steel.

[0075] In an embodiment, the container is arranged to hold a volume of at least 100 mL, such as at least 500 mL. In addition, the container may have a maximum volume of less than 5000 mL, such as less than 2500 mL, such as less than 1500 mL, such as 1000 mL or less.

[0076] In an embodiment of the first aspect of the invention, the separation system further comprises a control unit configured to determine the weight increase of the first container and the second container over time. Such a control unit may be the same as the control unit for controlling the alternating filling of the first container and the second container with the same type of measuring liquid.

[0077] The control unit may be further configured to determine or calculate the flow rate of the liquid phase discharged to the container based on the measured weight increase over time.

[0078] The control unit may comprise a computer program product configured for determining the weight gain over time.The control unit may thus comprise a processor and a communication interface for communicating with the scale.

[0079] For this purpose, the control unit may comprise means with processing capabilities in the form of a processing unit, such as a central processing unit, configured to execute computer code instructions, which may for example be stored on a memory.The processing unit may alternatively be in the form of a hardware component.

[0080] As an example, the control unit may be further configured for determining a flow rate of the measurement liquid based on the measured weight increase of the first container and the second container over time.The flow rate may be a mass flow rate or a volume flow rate.

[0081] Thus, the increase in weight of the container can be measured when the container is not emptied (ie, when the container is only filled).

[0082] The use of the flow measurement arrangement for measuring a parameter related to the weight of the measured liquid allows to omit the use of an additional flow sensor, since the liquid flow rate can be determined from the measured weight increase. Thus, in embodiments of the first aspect, the separation system may be free of any flow sensor arranged downstream of the liquid outlet at or downstream of which the flow measurement arrangement is arranged. That is, the centrifugal separator may be free of any additional flow sensor, apart from the flow measurement arrangement arranged downstream of one or more relevant liquid outlets.

[0083] As a second aspect of the present invention, there is provided a method for measuring the flow rate of a measuring liquid in a separation system comprising a centrifugal separator, the measuring liquid being selected from a liquid feed mixture and a separated liquid phase, the method comprising the following steps

[0084] a) filling a first container with the measuring liquid;

[0085] b) measuring how a parameter related to the weight of the measurement liquid in said first container changes over time during step a);

[0086] c) filling a second container with the same type of measuring liquid as in step a);

[0087] d) measuring how a parameter related to the weight of the measurement liquid in the second container changes over time during step c); and

[0088] e) Determining said flow rate of the measurement liquid based on the measurements of step b) and / or step c).

[0089] This aspect may generally present the same or corresponding advantages as the previous aspect. The effects and features of this second aspect are largely similar to those described above in conjunction with the first aspect. The embodiments mentioned in relation to the first aspect are largely compatible with the second aspect.

[0090] Step a) of filling the first container may also comprise stopping any outflow of measuring liquid from the first container. Similarly, step c) of filling the second container may comprise stopping any outflow of measuring liquid from the second container.

[0091] The parameter of steps b) and / or d) may be weight. The weight may be measured using a scale, such as a hanging scale. The mass flow rate may be calculated by determining the weight increase (Δw) of the container during a time interval (Δt) and then estimating Δw / Δt. The volume flow rate may be determined from the mass flow rate using the density of the liquid phase entering the container.

[0092] In an embodiment of the second aspect, step c) is performed while emptying the first container of the measurement liquid.

[0093] Hence, in an embodiment of the second aspect, the parameter related to the weight of the measurement liquid is the weight of the measurement liquid measured by the scale.

[0094] Step e) of determining the flow rate may be performed at discrete points in time, such as once per second. Step e) may be performed simultaneously with the execution of steps b) and / or d).

[0095] In an embodiment of the second aspect, the method further comprises the following steps

[0096] f) Refilling the first container with the measuring liquid while simultaneously emptying the second container of the measuring liquid.

[0097] Steps a) and f) may be part of a first filling cycle and thus part of a first measuring cycle.

[0098] Step c) can thus be part of a second filling cycle and thus part of a second measuring cycle.

[0099] In an embodiment, the first measurement cycle comprises step f) and the second measurement cycle comprises step c).

[0100] In an embodiment of the second aspect, the method comprises repeating the first measurement cycle after the second measurement cycle, and repeating the second measurement cycle after the first measurement cycle. Thus, the method may comprise performing the first measurement cycle, thereafter performing the second measurement cycle, thereafter performing the first measurement cycle, and so on.

[0101] In an embodiment of the second aspect, the separation system is a separation system according to any embodiment described above with respect to the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0102] The above and additional objects, features and advantages of the inventive concept will be better understood through the following illustrative and non-limiting detailed description with reference to the accompanying drawings. In the drawings, like reference numerals will be used for like elements unless otherwise stated.

[0103] Figure 1 is a schematic diagram of a separation system of the present disclosure, wherein a flow measurement arrangement is arranged downstream of a first liquid outlet.

[0104] Figure 2 It also includes a control unit Figure 1 Schematic diagram of the separation system.

[0105] Figure 3is a schematic diagram of a separation system of the present disclosure, wherein a flow measurement arrangement is arranged downstream of the second liquid outlet.

[0106] Figure 4 is a schematic illustration of a separation system for separating a cell culture mixture.

[0107] Figure 5 is a schematic illustration of a flow measurement arrangement according to an embodiment of the present disclosure that may be used in a separation system.

[0108] Figure 6 A first measurement cycle of the flow measurement arrangement is shown.

[0109] Figure 7 A second measurement cycle of the flow measurement arrangement is shown.

[0110] Figure 8 The different steps of the method of the present disclosure are schematically shown. DETAILED DESCRIPTION

[0111] Figure 1-4 generally describes the separation system as a whole, while Figure 5-7 Details of the flow measurement arrangement are shown. Figure 1-4 In the embodiment, the flow measurement arrangement 90 is arranged downstream of one of the liquid outlets of the centrifugal separator, i.e. the measuring liquid is the separated liquid phase. However, the flow measurement arrangement can also be arranged upstream of the inlet of the centrifugal separator, i.e. so that the measuring liquid is the liquid feed mixture.

[0112] Figure 1 A separation system 120 according to an embodiment of the present disclosure is schematically shown. For reasons of clarity, only the exterior of the rotatable assembly 101 of the centrifugal separator 100 is shown.

[0113] As discussed above, the centrifugal separator may be as disclosed in WO 2021 / 191023. Thus, the centrifugal separator may have a rotatable component arranged for multiple uses (such as a conventional stainless steel centrifuge barrel) or a rotatable component arranged for single use (such as a replaceable insert known from, for example, WO 2020 / 120357).

[0114] exist Figure 1 In the centrifugal separator 100 of FIG. 1 , the liquid feed mixture to be separated is supplied to the rotatable assembly 101 via the fixed inlet pipe 7 by means of a feed pump 204. In this example, the liquid feed mixture is separated into a liquid light phase and a liquid heavy phase.

[0115] After separation in the separation space of the rotatable assembly, the separated liquid light phase is discharged through the first liquid outlet to the first fixed outlet pipe 9 , while the separated heavy phase is discharged via the second liquid outlet to the second fixed outlet pipe 8 .

[0116] The first fixed outlet pipe 9 and the second fixed outlet pipe 8 may be flexible pipes.

[0117] Downstream of the second liquid outlet there is a peristaltic pump 50a arranged for facilitating the discharge of the second liquid phase. The peristaltic pump 50a also acts as a regulating valve and can thus be used to regulate the flow of the separated heavy phase discharged in the fixed pipe 8 or to shut off this flow.

[0118] Downstream of the first liquid outlet there is a regulating valve 52a for regulating the discharge of the separated liquid light phase in the fixed outlet pipe 9. Downstream of the regulating valve there is a flow measurement arrangement 90 arranged for receiving the discharged liquid light phase and for measuring the flow rate of the discharged liquid phase. Figure 5-8 The flow measurement arrangement 90 is described in further detail.

[0119] If also Figure 1 , the liquid light phase emptied from the flow measurement arrangement 90 is collected in a tank 205. The tank 205 has a larger volume than the container of the flow measurement arrangement 90. The tank 205 can be used for intermediate storage or long-term storage before further processing of the discharged liquid light phase. The tank 205 can have a volume of at least five times (such as at least ten times) the volume of the container of the flow measurement arrangement 90.

[0120] Figure 2 An embodiment of a separation system 120 is shown. The system 120 has Figure 1 , with the addition of a flow measurement arrangement 90 having a control unit 53 configured to determine the flow rate based on input of the weighing of the containers 60, 70 from the flow measurement arrangement 90. Thus, the control unit 53 is configured to receive (e.g. continuously or at discrete points in time) measurement data of the weight of the container 60. This is Figure 2 ” is indicated by arrow “Z1” in the figure. Moreover, the control unit 53 is further configured for determining the flow rate of the discharged separated liquid phase based on the measured weight increase of the containers 60, 70 as a function of time. The control unit 53 is also connected to the shut-off valve 52b in this embodiment, as indicated by arrow “Z2”. The control unit 53 comprises a communication interface, such as a transmitter / receiver, via which it can receive weight data from the gauges 61, 71 of the flow measurement arrangement 90. The control unit 53 is thus configured for receiving information on the weight of the containers 60, 70 of the flow measurement arrangement 90 as a function of time.

[0121] The control unit 53 may further be configured to determine the flow rate of the discharged liquid light phase using the measured weight of the containers 60, 70 as a function of time. For this purpose, the control unit 53 may include a device having processing capabilities in the form of a processing unit, such as a central processing unit, configured to execute computer code instructions, which may be stored, for example, on a memory. The processing unit may alternatively be in the form of a hardware component, such as an application specific integrated circuit, a field programmable gate array, etc.

[0122] The control unit 53 is also configured in this example for regulating the liquid flow through the shut-off valve 52b. For this purpose, the processing unit of the control unit 53 may also comprise computer code instructions for sending an operation request to the shut-off valve 52b.

[0123] It will be appreciated that a flow measurement arrangement 90 for measuring the weight of the measurement liquid may also be arranged downstream of the second liquid outlet and may therefore be used to measure the flow rate of the discharged liquid heavy phase. Figure 3 Thus, the separation system 120 may include a flow measurement arrangement 90 for measuring the weight of the measurement liquid downstream of either or both of the liquid outlets.

[0124] Figure 4 1 is a schematic illustration of a separation system 120 for separating a cell culture mixture. System 120 includes a fermenter 200 configured to contain a cell culture mixture. Fermenter 200 has an axially upper portion and an axially lower portion 200a. Fermentation in fermenter 200 can be used, for example, to express extracellular biomolecules, such as antibodies, from a mammalian cell culture mixture. After fermentation, the cell culture mixture is separated in centrifugal separator 100. As in Figure 4 As seen in FIG. 2 , the bottom of the fermenter 200 is connected to the bottom of the separator 100 via a connection 201 to the inlet conduit 7 of the separator. However, the cell culture mixture can also be supplied from the top of the centrifugal separator 100.

[0125] The connection 201 may be a direct connection or a connection via any other processing equipment, such as a tank. Thus, the connection 201 allows the cell culture mixture to be supplied from the axially lower portion 200a of the fermenter 200 to the inlet of the centrifugal separator 100, as indicated by arrow "A". There is a feed pump 204, which is arranged to pump the feed (i.e., the cell culture mixture from the fermenter 200) to the inlet of the separator 100.

[0126] After separation, the higher density separated cell phase is discharged to the fixed outlet conduit 8 via the second liquid outlet at the top of the separator, while the lower density separated liquid light phase (including expressed biomolecules) is discharged to the fixed outlet conduit 9 via the liquid light phase outlet at the bottom of the separator 100.

[0127] The flow rate of the separated liquid light phase discharged via the fixed outlet conduit 9 is determined by a flow measurement arrangement 90 (described further below).

[0128] The positive displacement pumps 50a, 50b can provide suction to the measurement liquid, thus allowing a lower feed pressure to be used by the feed pump 204, which thus promotes gentler handling of the cells in the separator 100. As an alternative, the feed pump 204 can be omitted entirely, and the cells can be drawn into the separator 100 using only the suction generated by the positive displacement pumps 50a, 50b.

[0129] The separated cell phase may be discharged to tank 203 for reuse in a subsequent fermentation process, such as in fermentor 200. The separated cell phase may be further recycled to the feed inlet of separator 100, as indicated by connection 202. The separated liquid light phase may be discharged via outlet conduit 9 to a further tank 205 or other processing equipment for subsequent purification of the expressed biomolecules.

[0130] Figure 4 A more detailed view of an embodiment of a flow measurement arrangement 90 is shown, which may be arranged downstream or upstream of a centrifugal separator 100 and is arranged for receiving a measurement liquid, such as a liquid feed mixture or a discharged liquid phase.

[0131] The flow measurement arrangement 90 comprises a first container 60 for holding a measurement liquid, which is suspended in a first suspended scale 61 for measuring the weight of the measurement liquid contained in the first container 60 .

[0132] Furthermore, the flow measurement arrangement 90 comprises a second container 70 for holding the measuring liquid, which is suspended in a second suspended scale 71 for measuring the weight of the measuring liquid contained in the second container 60 .

[0133] The first container 60 and the second container 70 are arranged in a parallel connection so that the three-way valve 81 can be used to determine to which container the measurement liquid is to be directed.

[0134] Furthermore, the flow measurement arrangement 90 is arranged to allow the first container 60 to be emptied of the measurement liquid while the second container 7 is being filled with the measurement liquid, and vice versa. This is accomplished by means of a pipe arrangement 95 and by changing the valves 82, 83 and 84 (as described below with respect to Figure 6 and Figure 7In this way, the flow measurement arrangement 90 allows alternate filling of the first container 60 and the second container 70 with the same type of measurement liquid, so that the measurement of the discharge flow can be performed without interruption or with little interruption.

[0135] The first container 60 and the second container 70 are flexible bags, each having a container inlet for receiving the discharged separated liquid light phase and a container outlet for draining the liquid phase from the container. In this embodiment, the inlet and outlet are the same conduits, i.e., conduit 11 for the first container 60 and conduit 14 for the second container 70. Thus, filling and emptying of the containers are performed via the same conduit.

[0136] The first container 60 and the second container 70 are two flexible bags each suspended in a scale. Therefore, the suspended scale 61 is configured to measure the weight of the container 60, while the suspended scale 71 is configured to measure the weight of the container 70.

[0137] The measured weight of the separated liquid light phase in the vessel is therefore a measure of the amount of liquid light phase discharged, and such measurement of the weight of the scale can be used to calculate the discharge flow rate of the separated liquid light phase.

[0138] The control unit 88 may also be part of the flow measurement arrangement 90. The unit receives the weight value from the first suspended scale 61 (as indicated by arrow "Z3") and the weight value from the second suspended scale 71 (as indicated by arrow "Z4") and calculates the flow rate therefrom, for example by measuring the mass flow rate (which determines the weight increase over time). The flow rate may be determined at discrete points in time, such as once per second. The control unit 88 may be the same control unit 53 used in the system 120 (for example, for controlling other regulating valves).

[0139] The pipe arrangement 95 is used to enable the measurement liquid to be conveyed to and from the first container 6 and to and from the second container 70. The pipe arrangement 95 comprises a single inlet pipe 9a for receiving the measurement liquid to be filled in the containers 60 and 70, and a first valve 81 for guiding the received measurement liquid in the pipe 10 into the first container 60 while preventing the measurement liquid from being conveyed in the pipe 13 to the second container 70 and vice versa.

[0140] Furthermore, the pipe arrangement 95 comprises a second valve 82 arranged on the pipe between the first valve 81 and the first container 60. This three-way valve 82 can be used to empty the first container 60 into the downstream pipe 12 with measuring liquid while the second container 70 is filled with measuring liquid.

[0141] Similarly, the pipe arrangement 95 comprises a third valve 83 arranged on the pipe between the first valve 81 and the second container 70. The three-way valve 83 can be used to empty the second container 70 into the downstream pipe 15 while filling the first container 60 with the measuring liquid.

[0142] Furthermore, the pipe arrangement 95 comprises: a single outlet pipe 16 downstream of the pipes 12 and 15, the pipe 12 being downstream of the first container 60 and the pipe 15 being downstream of the second container 70; and a fourth valve 84 for allowing the measurement liquid emptied from the first container 60 and the second container 70 to be conveyed out of the measurement arrangement 90 via the single outlet pipe 16. The liquid leaving the flow measurement arrangement 90 via the single outlet pipe 16 can be conveyed to a tank (such as, Figure 2 The tank 205 shown in FIG. 2 is a tube or pipe in contact with the fluid.

[0143] Figure 6 and Figure 7 Two filling and measuring cycles are shown. The path of the liquid is Figure 6 and Figure 7 Indicated by bold arrows.

[0144] exist Figure 6 In the first measurement cycle, the first valve 81 and the second valve 82 are used to direct the incoming measurement liquid in the single inlet pipe 9a to the first container 60. Therefore, the liquid level 97 of the first container 60 rises, and the increased weight of the first container 60 is measured by the gauge 61, so that the flow rate of the measurement liquid can be determined. At the same time, the third valve 83 and the fourth valve 84 are used to empty any liquid in the second container 70 from the second container 70 to the single outlet pipe 16. Therefore, the liquid level 98 of the second container decreases. The path of the liquid in Figure 6 Indicated by bold arrows.

[0145] exist Figure 7 In the second measuring cycle, the first valve 81 and the third valve 83 are used to direct the incoming measuring liquid in the single inlet pipe 9a to the second container 70. Therefore, the liquid level 98 of the second container 70 rises, and the increased weight of the second container 70 is measured by the gauge 71, so that the flow rate of the measuring liquid can be determined. At the same time, the second valve 82 and the fourth valve 84 are used to empty any liquid in the first container 60 from the first container 60 to the single outlet pipe 16. Therefore, the liquid level 97 of the first container 60 decreases.

[0146] With the first measuring cycle and the second measuring cycle the flow rate of the measuring liquid from the centrifugal separator can be determined almost continuously.

[0147] Figure 8The steps of a method 300 for measuring the flow rate of a measuring liquid in a separation system including a centrifugal separator are shown. The separation system may be a separation system as discussed above herein. The method 300 comprises the following steps

[0148] a) filling 301 a first container 60 with the measuring liquid;

[0149] b) measuring 302 how a parameter related to the weight of the measurement liquid in said first container 6 changes over time during step a);

[0150] c) filling 303 the second container 70 with the measuring liquid. This step can be performed while emptying the first container 60 of the measuring liquid;

[0151] d) measuring 304 how a parameter related to the weight of the measurement liquid in the second container 70 changes over time during step c); and

[0152] e) Determining 305 said flow rate of the measurement liquid based on the measurements of step b) and / or step c).

[0153] In this example, method 300 further includes the following steps:

[0154] f) Refilling 306 the first container 60 with the measuring liquid while simultaneously emptying the second container 70 of the measuring liquid.

[0155] As discussed herein above, the parameter related to the weight of the measuring liquid may be the weight of the measuring liquid measured by the scale.

[0156] In the above, the inventive concept has mainly been described with reference to a limited number of examples. However, as is readily appreciated by a person skilled in the art, other examples than those disclosed above are equally possible within the scope of the inventive concept as defined by the appended claims.

Claims

1. A separation system (120), comprising a centrifugal separator (100) for separating a liquid feed mixture, wherein: The centrifugal separator (100) is arranged for separating the liquid feed mixture into at least one separated liquid phase and discharging the at least one separated liquid phase, And further, wherein the separation system (120) comprises a flow measurement arrangement (90) arranged for receiving a measurement liquid selected from the liquid feed mixture and the separated liquid phase, wherein the flow measurement arrangement comprises a first container (60) for holding a measurement liquid, first means (61) for measuring a parameter related to the weight of a measurement liquid contained in said first container (60), a second container (70) for holding a measurement liquid, second means (71) for measuring a parameter related to the weight of a measurement liquid contained in said second container (70), The flow measurement arrangement (90) is further arranged to allow the measuring liquid of the first container (60) to be emptied while another container of the flow measurement arrangement (90) is filled with the same type of measuring liquid, and vice versa, thereby allowing the first container (60) and another container of the flow measurement arrangement (90) to be alternately filled with the same type of measuring liquid.

2. The separation system (120) according to claim 1, wherein: The further container of the flow measurement arrangement (90) is the second container (70).

3. The separation system (120) according to claim 2, wherein: The flow measurement arrangement (90) comprises a conduit arrangement (95) for conveying a measurement liquid to and from the first container (60) and to and from the second container (70).

4. The separation system (120) according to claim 3, wherein: The conduit arrangement (95) comprises a single inlet conduit (9a) for receiving the measuring liquid to be filled in the first container (60) and the second container (70).

5. The separation system (120) according to claim 4, wherein: The conduit arrangement (95) comprises a first valve (81) for directing the measurement liquid in the single inlet conduit to the first container (60) while preventing the measurement liquid from being conveyed to the second container (70), and vice versa.

6. The separation system (120) according to claim 5, wherein: The conduit arrangement (95) comprises a second valve (82) and a third valve (83), wherein the second valve (82) is arranged to allow the first container (60) to be emptied of the measuring liquid while the second container (70) is filled with the measuring liquid, and the third valve (83) is arranged to allow the second container (70) to be emptied of the measuring liquid while the first container (60) is filled with the measuring liquid.

7. The separation system (120) according to any one of claims 3 to 6, wherein: The conduit arrangement (95) comprises a single outlet conduit (16) arranged for conveying the measurement liquid emptied from the first container (60) and the second container (70) out of the flow measurement arrangement (90).

8. The separation system (120) according to claim 7, wherein: The conduit arrangement (95) comprises a fourth valve (84) for allowing the measurement liquid emptied from the first container (60) and the second container (70) to be conveyed out of the measurement arrangement (90) via the single outlet conduit (16).

9. The separation system (120) according to any of the preceding claims, further comprising a control unit for controlling the alternating filling of the first container (60) and the second container (70) with the same type of measuring liquid.

10. The separation system (120) according to any preceding claim, wherein: The first container (60) and / or the second container (70) is a flexible bag.

11. The separation system (120) according to any preceding claim, wherein: The first device (61) for measuring a parameter related to the weight of the measuring liquid contained in the first container (60) and / or the second device (71) for measuring a parameter related to the weight of the measuring liquid contained in the second container (70) is a scale, such as a hanging scale.

12. A method (300) for measuring the flow rate of a measuring liquid in a separation system comprising a centrifugal separator, the measuring liquid being selected from a liquid feed mixture to be separated and a separated liquid phase, the method comprising the following steps a) filling (301) a first container (60) with the measuring liquid; b) measuring (302) how a parameter related to the weight of the measurement liquid in the first container (60) changes over time during step a); c) filling (303) a second container (70) with the same type of measuring liquid as in step a); d) measuring (304) how a parameter related to the weight of the measurement liquid in the second container (70) changes over time during step c); and e) determining ( 305 ) said flow rate of the measurement liquid based on the measurements of step b) and / or step c).

13. The method (300) of claim 12, wherein: Step c) is performed while the first container (60) is emptied of the measurement liquid.

14. The method (300) of claim 13, wherein: The method further comprises the following steps f) refilling (306) the first container (60) with the measuring liquid while simultaneously emptying the second container (70) of the measuring liquid.

15. The method (300) according to any one of claims 12 to 14, wherein: The separation system is a separation system according to any one of claims 1-11.

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