SEPARATING SYSTEM

Abstract

A separating system, for example for separating material from a suspension such as a biological suspension, is disclosed herein. The system comprises a separation vessel arranged to enable the formation of a cyclone therewithin. For example, the separation vessel may be at least partially conical in shape for enabling the formation of a cyclone therewithin. The separation vessel comprises a fluid inlet, an underflow outlet and an overflow outlet. The system also comprises at least one of an underflow outlet fluid control means for controlling the flow of fluid through the underflow outlet, and an overflow outlet fluid control means for controlling the flow of fluid through the overflow outlet. The system may further comprise an inlet fluid control means for controlling the flow of fluid through the fluid inlet.

Claims

1. A cell suspension separating system for separating material from a biological suspension, the system comprising: a separation vessel arranged to enable the formation of a cyclone therewithin, the separation vessel comprising a fluid inlet, an underflow outlet and an overflow outlet; an inlet fluid control means for controlling the flow of fluid through the inlet; and an overflow outlet fluid control means for controlling the flow of fluid through the overflow outlet; further comprising a sensor coupled to a controller and arranged to sense a parameter of the fluid flowing through at least one of the fluid inlet and the overflow outlet, and wherein the controller is configured to control at least one of the fluid control means based on sensor signals received from the sensor.

2. The system of claim 1 further comprising an underflow outlet fluid control means for controlling the flow of fluid through the underflow outlet.

3. (canceled)

4. (canceled)

5. (canceled)

6. The system of claim 1, further comprising: a first sensor coupled to a controller and arranged to sense a parameter of the fluid flowing through the fluid inlet; and a second sensor coupled to the controller and arranged to sense a parameter of the fluid flowing through at least one of: (i) the underflow outlet; (ii) the overflow outlet; and (iii) the separation vessel; and wherein the controller is configured to control the inlet fluid control means and at least one of: (iv) the underflow outlet fluid control means; and (v) the overflow outlet control means; based on sensor signals received from the sensor.

7. The system of claim 1 wherein the sensor is selected from at least one of: a turbidity sensor, a temperature sensor, a pressure sensor, a flowrate sensor, a capacitive sensor and an impedance sensor.

8. The system of claim 1, wherein at least one of the sensors is a turbidity sensor, and the controller is configured to make a determination of the density of the fluid based on sensor signals received from the turbidity sensor, and control at least one of the fluid control means based on the determined density of the fluid.

9. The system of claim 1, further comprising a feed vessel for containing a biological suspension containing material coupled to the fluid inlet, and wherein the controller is configured to control the pressure of the feed vessel for controlling the flow of fluid through the fluid inlet.

10. The system of claim 1, wherein the fluid control means are configured to adjustably vary the flow rate and/or pressure of fluid flowing through the corresponding inlet or outlet.

11. (canceled)

12. A cell suspension separating method for separating material from a biological suspension, the method comprising: feeding a biological fluid suspension containing material into a separation vessel via a fluid inlet for establishing a cyclone in the separation vessel about a longitudinal axis of the separation vessel, wherein the vessel comprises an underflow outlet and an overflow outlet and wherein the fluid is fed transverse to the longitudinal axis of the separation vessel; receiving sensor signals indicative of a parameter of the fluid; and controlling the flow of fluid through at least one of the fluid inlet and the overflow outlet to control the separation of material from the biological suspension based on the received sensor signals.

13. The method of claim 12, further comprising receiving sensor signals indicative of a parameter of the fluid flowing through at least one of: (i) the fluid inlet; (ii) the underflow outlet; (iii) the overflow outlet; (iv) the separation vessel; and controlling the flow of fluid through at least one of: (iv) the underflow outlet; and (v) the overflow outlet; to control the separation of material from the biological suspension.

14. The method of claim 12, further comprising controlling the flow of fluid into the separation vessel via the underflow outlet based on the received sensor signals.

15. (canceled)

16. The method of claim 12, further comprising controlling the flow of fluid through at least one of: (i) the fluid inlet; and (ii) the overflow outlet; based on the flow rate and/or pressure of fluid through the fluid inlet to control the separation of material from the biological suspension.

17. The method of claim 12, further comprising controlling the pressure of the biological suspension fed into the separation vessel to control the separation of material from the biological suspension in the separation vessel.

18. A cell suspension separating controller for controlling the separation of material from a biological suspension in a separation vessel having a fluid inlet, an overflow outlet and an underflow outlet, wherein the controller is configured to control the flow rate and/or pressure of fluid through at least one of: (i) the overflow outlet; and (ii) the fluid inlet; based on the flow rate and/or pressure of fluid through at least one of the fluid inlet, the underflow outlet, the overflow outlet, and inside the separation vessel to control the separation of material from the biological suspension.

19. The controller of claim 18, wherein the controller is configured to receive sensor signals indicative of a parameter of the fluid flowing through at least one of the fluid inlet, the underflow outlet, the overflow outlet, and inside the separation vessel; and wherein the controller is configured to control, based on sensor signals received from the sensor, at least one of: (i) an inlet fluid control means for controlling the flow of fluid through the inlet; and (ii) an overflow outlet fluid control means for controlling the flow of fluid through the overflow outlet.

20. The controller of claim 19 wherein the controller is further configured to control an underflow outlet fluid control means for controlling the flow of fluid through the underflow outlet based on the received sensor signals.

21. The controller of claim 18, wherein the controller is configured to determine the density of the fluid and control the flow of fluid through at least one of the fluid control means based on the determined density of the fluid.

22. The controller of claim 18, wherein the controller is configured to operate in two modes: (i) an initialisation mode for establishing a cyclone in the separation vessel; and (ii) a cyclone mode for separating material from a biological suspension.

23. The controller of claim 22 wherein: in the initialisation mode the controller is configured to inhibit the flow of fluid through the overflow outlet; and in the cyclone mode the controller is configured to adjustably control the flow of fluid through at least one of (i) the overflow outlet and (ii) the underflow outlet.

24. The controller of claim 23 wherein the controller is configured to determine when to switch between the initialisation mode and the cyclone mode based on a pressure of fluid passing through at least one of (i) the underflow outlet and (ii) the overflow outlet.

25. (canceled)

Description

DRAWINGS

[0060] Embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0061] FIG. 1 shows a functional schematic view of an example separation system;

[0062] FIG. 2 shows another functional schematic view of an example separation system;

[0063] FIG. 3 shows another functional schematic view of an example separation system;

[0064] FIG. 4 shows another functional schematic view of an example separation system:

[0065] FIG. 5 shows another functional schematic view of an example separation system;

[0066] FIG. 6 shows another functional schematic view of an example separation system; and

[0067] FIG. 7 shows another functional schematic view of an example separation system.

SPECIFIC DESCRIPTION

[0068] Embodiments of the disclosure relate to a separating system, for example for separating material such as cells and/or beads from a suspension such as a cell suspension, although it will be understood that the separating system may find application in other fields of use. The system involves an adaptation of a conventional hydrocyclone system to include a flow control means that allows control of the system meaning that the system does not have to be adapted to consider Ru or Ro (or even Du or Do). The separation system can be used for any type of system, regardless of tubing or size and does not need to be carefully balanced and fine-tuned to take into account Ru or Ro, unlike the systems of the prior art.

[0069] In the cell therapy industry where yield is extremely important, the use of an optimally tuned separation device is critical and thus the presently developed hydrocyclone will be important to the industry. However, it is noted that the device could also have utility in other industries, particularly those where an increased yield would be desirable.

[0070] FIG. 1 shows an example separating system 100 of embodiments of the disclosure. The system 100 comprises a separation vessel 101 having a fluid inlet 103, an underflow outlet 107 and an overflow outlet 105. In the example shown the separation vessel 101 is conical in shape to enable the formation of a cyclone therewithin, however it will be understood that in other examples the separation vessel 101 may have another shape. The fluid inlet 103 is proximate to the overflow outlet 105 and configured to direct fluid into the vessel transverse to (for example, perpendicular to) and eccentric to a longitudinal axis of the conical separation vessel 101 such that it creates a cyclone effect in the vessel about the longitudinal axis. The fluid inlet may have a diameter between 1.0 and 4.0 mm. The underflow outlet 107 and overflow outlet 105 are coaxial with the longitudinal axis of the conical separation vessel 101. The underflow outlet 107 may have a diameter between 0.1 and 3.0 mm, preferably 0.1 to 1.0 mm, and the overflow outlet 105 may have a diameter in the range of 0.1 to 3.0 mm, or preferably 0.1 to 1.0 mm.

[0071] In the example shown in FIG. 1, the fluid inlet 103 is coupled to a feed vessel 150 via an inlet fluid control means 109. In the example shown the inlet fluid control means 109 is a continuous pump such as a rotary or peristaltic pump. If a peristaltic pump (or any other pulsatile pump) is used it may be coupled to a means to minimise pulsing, for example a flexible tube coupled to the peristaltic pump that is configured to elastically absorb the pulses in pressure in a manner similar to the “windkessel” effect). The overflow outlet 105 is coupled to a waste vessel 125 via an overflow outlet fluid control means 111 and a waste line 127. The overflow outlet fluid control means 111 is also a continuous pump such as a peristaltic pump. The underflow outlet 107 is also coupled to the feed vessel 150 via feed line 152. In the example shown the feed vessel 150 also comprises an input line 170.

[0072] In some examples the system 100 also comprises a controller (not shown, but an example of which is described below with reference to FIG. 5) for controlling the system 100, and in particular for controlling the inlet fluid control means 109 and the overflow outlet fluid control means 111.

[0073] In the example shown in FIG. 1, which may be used for example for perfusion of biological cells in cell suspensions, the waste vessel 125 can be used for removing fluid (such as cell media) or particles of lower mass, separated by a cyclone formed in the separation vessel 101. Any higher mass particles (such as cells) would separate out via the underflow outlet 107 and be recycled back into the feed vessel 150, whereas the fluid (such as the cell media) would separate out via the overflow outlet 105 and into the waste vessel 125. The input line 170 may be used to replenish any fluid (such as cell media) removed to the waste vessel 125.

[0074] The inlet fluid control means 109 is operable to control the flow of fluid though the fluid inlet 103. The overflow outlet fluid control means 111 is operable to control the flow of fluid through the overflow outlet 105. Controlling the flow of fluid through the fluid inlet 103 and the overflow outlet 105 may thus control the formation and functioning of a cyclone in the separation vessel 101.

[0075] In use, a fluid (for example a suspension containing cells) is fed into the separation vessel 101 from the feed vessel 150 via the fluid inlet 103 transverse to and eccentric to a longitudinal axis of the separation vessel 101 such that it creates a cyclone effect in the vessel 101. The inlet fluid control means 109 is operated to control the flow rate and/or pressure of fluid fed into the separation vessel 101. The flow of fluid (such as the flow rate and/or pressure) through the overflow outlet 105 is also controlled by controlling the overflow outlet fluid control means 111. Controlling the inlet fluid control means 109 and/or the overflow outlet fluid control means 111 can therefore control the formation of a cyclone and/or a cyclone in the separation vessel 101.

[0076] Preferably the flow of fluid through the fluid inlet 103 and the overflow outlet 105 is controlled by controlling the inlet fluid control means 109 and/or the overflow outlet flow control means 111 such that the flow rate of fluid through the underflow outlet 107 is greater than the flow rate of fluid through the overflow outlet 105.

[0077] Once a cyclone is established in the separation vessel 101, in the example of the system 100 being used for cell perfusion, cells may separate out from the separation vessel 101 via the underflow outlet 107 and be fed back (i.e. recycled) into feed vessel 150 via input line 152. Waste media may separate out from the separation vessel 101 and be extracted by the overflow outlet fluid control means 111 via the overflow outlet 105 and into waste vessel 125.

[0078] The degree to which fluid is separated out into the waste vessel 125 may be determined based on at least one of (i) a parameter of the fluid and (ii) time. For example, control of the overflow outlet fluid control means 111 may be based on a parameter of the fluid entering and/or in and/or leaving the separation vessel 101. Similarly, control of the inlet fluid control means 109 may be based on a parameter of at least one of (i) the fluid entering (ii) the fluid in and (iii) the fluid leaving the separation vessel 101.

[0079] For example, if the fluid reaches a selected threshold density (for example, as determined by turbidity), it may be determined that a selected degree of fluid should be extracted via the overflow outlet 105. Additionally or alternatively, the extraction of fluid via the overflow outlet 105 may be a continuous process, and the flow rate of fluid extracted via the overflow outlet 105 may be based on a parameter, such as the density, of fluid entering and/or in and/or leaving the separation vessel 101. In other examples, the extraction of fluid via the overflow outlet 105 may be based on at least one of: (i) levels of toxic by-products (such as lactate or ammonia) from cell metabolism reaching a selected threshold; (ii) cell phenotype changes (for example during differentiation of pluripotent cells); (iii) the size and/or mass of particles such as cells that are desired to be separated from the suspension, for examples particles with a size and/or mass above or below a selected threshold.

[0080] The parameter of the fluid may be determined based on fluid entering the fluid inlet 103, fluid passing through the underflow outlet 107 and/or fluid passing through the overflow outlet 105.

[0081] Additionally or alternatively, if a threshold time interval has passed it may be determined to extract a selected amount of fluid via the overflow outlet 105, for example where the volume of fluid extracted is determined based on a function of the time interval.

[0082] In the example shown in FIG. 1 the pressure of the fluid passing through the fluid inlet 103 may be maintained between 0.5 and 4 bar.

[0083] It will be understood that although a controller is not shown in FIG. 1, the functionality described above may be performed by a controller operable to control the inlet fluid control means 109 and the overflow outlet fluid control means 111, as described below with reference to, and as shown in, FIG. 5. It will also be understood that the system 100 may comprise sensors coupled to, for example, the fluid inlet 103, the overflow outlet 105 and/or the underflow outlet 107, for sensing the parameter of the fluid discussed above, also as described below with reference to, and as shown in, FIG. 5. In some examples there may also be a sensor inside the separation vessel 101, in the feed vessel 150 and/or waste vessel 125.

[0084] It will also be understood that in some examples the system 100 may also comprise an optional underflow outlet fluid control means, also as described below with reference to, and as shown in, FIG. 5.

[0085] In addition, while in the example shown the overflow outlet 105 is coupled to the waste vessel 125, in some examples it will be understood that overflow outlet 105 may be coupled to the feed vessel 150, for example when the system is intended to be used to remove particles such as cells from the suspension (e.g. when the desired product is in the media such as viruses and exosomes).

[0086] FIG. 2 shows another separating system 200 of embodiments of the disclosure. The system 200 of FIG. 2 is in many respects similar to the system of FIG. 1 described above with like reference numbers indicating similar or the same entities, however instead of the overflow outlet fluid control means 111 being a continuous pump such as a peristaltic pump, in the example shown in FIG. 2 the overflow outlet fluid control means 211 is non-continuous pump, and in the example shown is a syringe pump. As a result, the example shown in FIG. 2 also does not need a waste vessel.

[0087] FIG. 3 shows another separating system 300 of embodiments of the disclosure. The system 300 of FIG. 3 is in many respects similar to the system of FIGS. 1 and 2 described above with like reference numbers indicating similar or the same entities, however instead of the overflow outlet fluid control means 111 being a continuous pump such as a peristaltic pump, or a non-continuous pump, in the example shown in FIG. 3 the overflow outlet fluid control means 311 is a fluid resistor. The resistance of the fluid resistor can be adjusted to control the flow of fluid through the overflow outlet fluid control means 311. This adjustment may, for example, be a passive action (for example the tube of the fluid resistor through which the fluid flows may be configured to expand with pressure), and/or an active action (for example by operation of a proportional solenoid valve).

[0088] FIG. 4 shows another example separating system 400 of embodiments of the disclosure, and is similar to the system described above with reference to FIG. 1 with like reference numbers indicating similar or the same entities. However, the system of FIG. 4 is slightly different due to its different intended function—whereas the system of FIGS. 1 to 3 may be used, for example, for cell perfusion, the system of FIG. 4 may be configured for use, for example, for cell harvest.

[0089] The system 400 comprises a separation vessel 401 having a fluid inlet 403, an underflow outlet 407 and an overflow outlet 405. The separation vessel 401 is conical in shape to enable the formation of a cyclone therewithin. The fluid inlet 403 is proximate to the overflow outlet 405 and configured to direct fluid into the vessel transverse to (for example, perpendicular to) and eccentric to the longitudinal axis of the conical separation vessel 401. The underflow outlet 407 and overflow outlet 105 are coaxial with the longitudinal axis of the conical separation vessel 401.

[0090] In the example shown in FIG. 4, the fluid inlet 403 is coupled to a feed vessel 450 via an inlet fluid control means 409. In the example shown the inlet fluid control means 409 is a continuous pump such as a peristaltic pump. The overflow outlet 405 is coupled to a waste vessel 425 via an overflow outlet fluid control means 411 and a waste line 427. The overflow outlet fluid control means 411 is also a continuous pump such as a peristaltic pump. The underflow outlet 407 is coupled to a harvest vessel 408 via a harvest line 452.

[0091] In some examples the system 400 also comprises a controller (not shown, but an example of which is described below with reference to FIG. 5) for controlling the system 400, and in particular for controlling the inlet fluid control means 409 and the overflow outlet fluid control means 411.

[0092] In the example shown in FIG. 4, which as noted above, may be used for example for cell harvest, the waste vessel 425 can be used for removing less dense fluid (such as cell media) separated by a cyclone formed in the separation vessel 401. Any higher density particles (such as cells) would separate out via the underflow outlet 407 into harvest vessel 408.

[0093] The inlet fluid control means 409 is operable to control the flow of fluid though the fluid inlet 403. The overflow outlet fluid control means 411 is operable to control the flow of fluid through the overflow outlet 105. Controlling the flow of fluid through the fluid inlet 403 and the overflow outlet 405 may thus control the formation and functioning of a cyclone in the separation vessel 401.

[0094] In use a fluid (for example a biological suspension containing cells) is fed into the separation vessel 401 transverse to and eccentric to the longitudinal axis of the separation vessel 401 from the feed vessel 450 via the fluid inlet 403. The inlet fluid control means 409 is controlled to control the flow rate and/or pressure of fluid fed into the separation vessel 401. The flow of fluid (such as the flow rate and/or pressure) through the overflow outlet 405 is also controlled by controlling the overflow outlet fluid control means 411. Controlling the inlet fluid control means 409 and/or the overflow outlet fluid control means 411 can therefore control the formation of the cyclone in the separation vessel 401.

[0095] Preferably the flow of fluid through the fluid inlet 403 and the overflow outlet 405 is controlled by controlling the inlet fluid control means 409 and/or the overflow outlet flow control means 411 such that the flow rate of fluid through the underflow outlet 407 is greater than the flow rate of fluid through the overflow outlet 405.

[0096] Once a cyclone is established in the separation vessel 401, in the example of the system 400 being used for cell harvest, cells may separate out from the separation vessel 401 via the underflow outlet 407 and into harvest vessel 408. Cell media may separate out from the separation vessel 401 and be extracted by the overflow outlet fluid control means 411 via the overflow outlet 405 and into waste vessel 425.

[0097] The degree to which fluid is separated out into the waste vessel 425 may be determined based on a parameter of the fluid and/or time. For example, control of the overflow outlet fluid control means 411 may be based on a parameter of the fluid entering and/or in and/or leaving the separation vessel 401. Similarly, control of the inlet fluid control means 409 may be based on a parameter of the fluid entering and/or in and/or leaving the separation vessel 401. The parameter of the fluid may be determined based on fluid entering the fluid inlet 403, fluid passing through the underflow outlet 407 and/or fluid passing through the overflow outlet 405.

[0098] It will be understood that although a controller is not shown in FIG. 4, the functionality described above may be performed by a controller operable to control the inlet fluid control means 409 and the overflow outlet fluid control means 411. It will also be understood that the system 100 may comprise sensors coupled to, for example, the fluid inlet 403, the overflow outlet 405 and/or the underflow outlet 407, for sensing the parameter of the fluid discussed above. In some examples there may also be a sensor inside the separation vessel 401, in the feed vessel 450, in the harvest vessel 408 and/or waste vessel 425.

[0099] FIG. 5 shows another example separating system 500 of embodiments of the disclosure, and is similar to the system described above with reference to FIGS. 1 to 4 with like reference numbers indicating similar or the same entities. However, the system of FIG. 5 also has an optional controller 550 for controlling operation of the system 500.

[0100] As with the system of FIG. 1, the system 500 shown in FIG. 5 comprises a separation vessel 501 having a fluid inlet 503, an underflow outlet 507 and an overflow outlet 505. The separation vessel 501 is conical in shape to enable the formation of a cyclone therewithin. The fluid inlet 503 is proximate to the overflow outlet 505 and configured to direct fluid into the separation vessel 501 transverse to and eccentric to the longitudinal axis of the conical vessel 501. The underflow outlet 507 and overflow outlet 505 are coaxial with the longitudinal axis of the conical separation vessel 501.

[0101] In the example shown in FIG. 1, the fluid inlet 503 is coupled to a feed vessel 550 via an inlet fluid control means 509. In the example shown the inlet fluid control means 509 is a continuous pump such as a peristaltic pump. The overflow outlet 505 is coupled to a waste vessel 525 via an overflow outlet fluid control means 511 and a waste line 527. The overflow outlet fluid control means 511 is also a continuous pump such as a peristaltic pump. The underflow outlet 507 is also coupled to the feed vessel 550 via an underflow outlet fluid control means 557 and a feed line 552. In the example shown the feed vessel 550 also comprises an input line 570 and a valve 590.

[0102] Sensors are also coupled to the input and outputs of the separation vessel 501. An inlet sensor 551 is coupled to the fluid inlet 503, an overflow sensor 553 is coupled to the overflow outlet 503 and an underflow sensor 555 is coupled to the underflow outlet 507. The sensors 551, 553, 555 may be selected from at least one of: a turbidity sensor, a temperature sensor, a pressure sensor, a capacitive sensor and an impedance sensor.

[0103] The system 500 also comprises a controller 550 for controlling the system 500. The controller 550 is coupled to the inlet fluid control means 509, the overflow outlet fluid control means 511 and the underflow outlet fluid control means 557. The controller 550 is also coupled to the inlet sensor 551, the overflow sensor 553 and the underflow sensor 555. The controller is also coupled to valve 590.

[0104] In the example shown in FIG. 5, which may be used for example for perfusion of biological cells in cell suspensions, the waste vessel 525 can be used for removing less dense fluid (such as cell media) separated by a cyclone formed in the separation vessel 501. Any higher density particles (such as cells) would separate out via the underflow outlet 507 and be recycled back into the feed vessel 550, whereas the less dense fluid (such as the cell media) would separate out via the overflow outlet 505 and into the waste vessel 525. The input line 570 may be used to replenish any fluid (such as cell media) removed to the waste vessel 525.

[0105] The inlet fluid control means 509 is operable to control the flow of fluid though the fluid inlet 103. The overflow outlet fluid control means 511 is operable to control the flow of fluid through the overflow outlet 105. The underflow outlet fluid control means 557 is operable to control the flow of fluid through the underflow outlet 557. The valve 590 may be controlled to control the pressure in the feed vessel 550, and thus the pressure of fluid flowing into the separation vessel 501.

[0106] The inlet sensor 551 is operable to sense a parameter of the fluid flowing through the fluid inlet 503. The overflow sensor 553 is operable to sense a parameter of fluid flowing through the overflow outlet 505. The underflow sensor 555 is operable to sense a parameter of fluid flowing through the underflow outlet 507.

[0107] The controller 550 is operable to control the inlet fluid control means 509, the overflow outlet fluid control means 511, the underflow outlet fluid control means 557 and optionally valve 590 to control the flow of fluid into and out of the separation vessel 501. The valve 590 may be operable to control the pressure in the feed vessel 590 and therefore the pressure of fluid flowing into the separation vessel 501, for example by introducing a fluid such as a gas into the feed vessel 590, or allowing a pressurised fluid such as a gas to escape the feed vessel 590. It will be understood that in some examples the harvest vessel and/or waste vessel (if present) may also comprise a similar valve.

[0108] The controller 550 is also operable to control to the inlet sensor 551, the overflow sensor 553 and the underflow sensor 555. The inlet sensor 551, the overflow sensor 553 and the underflow sensor 555 are configured to send sensor signals indicative of a parameter of the fluid to the controller 550. The controller 550 is configured to make a determination of a parameter of the fluid based on the received sensor signals.

[0109] In use a fluid (for example a biological suspension containing cells) is fed into the separation vessel 501 transverse to and eccentric to the longitudinal axis of the separation vessel 501 from the feed vessel 550 via the fluid inlet 503. The inlet fluid control means 509 is controlled by the controller 550 to control the flow rate and/or pressure of fluid fed into the separation vessel 501. The flow of fluid (such as the flow rate and/or pressure) through the overflow outlet 505 is also controlled by the controller 550 by controlling the overflow outlet fluid control means 511 and/or the underflow outlet fluid control means 557. Controlling the inlet fluid control means 509 and/or the overflow outlet fluid control means 511 and/or underflow outlet fluid control means 557 can therefore control the formation of the cyclone in the separation vessel 501.

[0110] Preferably the flow of fluid through the fluid inlet 503 and the overflow outlet 505 is controlled by controlling the inlet fluid control means 509 and/or the overflow outlet flow control means 511 such that the flow rate of fluid through the underflow outlet 507 is greater than the flow rate of fluid through the overflow outlet 505.

[0111] Once a cyclone is established in the separation vessel 501, in the example of the system 500 being used for cell perfusion, cells may separate out from the separation vessel 501 via the underflow outlet 507 and be fed back (i.e. recycled) into feed vessel 550 via input line 552. Waste media may separate out from the separation vessel 501 and be extracted by the overflow outlet fluid control means 511 via the overflow outlet 505 and into waste vessel 525.

[0112] In the example shown in FIG. 5, control of the fluid control means, such as the inlet fluid control means 509, the overflow outlet fluid control means 511 and/or the underflow outlet fluid control means 557 is based on a parameter of the fluid entering and/or in and/or leaving the separation vessel 501. Control of the valve 590 may also be based on a parameter of the fluid entering and/or in and/or leaving the separation vessel 501. This is done by the controller 550 controlling operation of the inlet sensor 551, the overflow sensor 553 and the underflow sensor 555 to receive sensor signals indicative of a parameter of the fluid at those points. The controller 550 makes a determination of a parameter of the fluid based on the received sensor signals, and determines what control of the inlet fluid control means 509, the overflow outlet fluid control means 511, the underflow outlet fluid control means 557 and/or valve 590 is needed based on the determined parameters of the fluid.

[0113] For example, if the fluid entering the separation vessel 501 reaches a selected threshold density (for example, as determined by inlet sensor 551 which may be a turbidity sensor), it may be determined by the controller that fluid should be extracted via the overflow outlet 505. The amount of fluid that is extracted may be based on the determined density of the fluid, for example the amount of fluid extracted may be proportional to the difference between the measured density and the threshold density. This may be done by controlling operation of the overflow outlet control means 511 and/or the underflow outlet control means 557.

[0114] Additionally or alternatively, the extraction of fluid via the overflow outlet 505 may be a continuous process, and the flow rate of fluid extracted via the overflow outlet 505 may be based on a parameter, such as the density, of fluid entering and/or in and/or leaving the separation vessel 501. For example, the controller may have a feedback control loop that continuously monitors a parameter of the fluid (such as the density) and controls operation of the overflow outlet control means 511 as a continuous process based on the feedback control loop.

[0115] Additionally or alternatively, if a threshold time interval has passed it may be determined to extract a selected amount of fluid via the overflow outlet 505, for example where the volume of fluid extracted is determined based on a function of the time interval. For example, the controller 550 may extract a selected amount of fluid repeatedly at a selected time interval via the overflow outlet 505 by controlling the overflow outlet fluid control means 511.

[0116] It will be understood that although the system 500 shown in FIG. 5 comprises an inlet fluid control means 509, an overflow outlet fluid control means 511 and an underflow outlet fluid control means 557, it will be understood that in some examples the system 500 may not comprise all three control means. In addition, although the system 500 shown in FIG. 5 comprises an inlet sensor 551, an overflow sensor 553 and an underflow sensor 555, in some examples the system 500 may only comprise two or even only one sensor. In addition, it will be understood that the valve 590 is optional.

[0117] The controller 550 may be configured to operate in two modes: [0118] (i) an initialisation mode for establishing a cyclone in the separation vessel; and [0119] (ii) a cyclone mode for separating material from suspensions, e.g. cells from a suspension.

[0120] In the initialisation mode the controller 550 may be configured to inhibit the flow of fluid through the overflow outlet 505, but only, for example, through the fluid inlet 503 and/or the underflow outlet 507. In some examples, in the initialisation mode the controller 550 may be configured to control the flow of fluid through the overflow outlet 505 such that no fluid flows through the overflow outlet 505 (for example, so that it is blocked).

[0121] In the cyclone mode the controller 550 may be configured to adjustably control the flow of fluid through at least one of (i) the overflow outlet 505 and (ii) the underflow outlet 507. The controller 550 may be configured to determine when to switch between the initialisation mode and the cyclone mode based on a parameter, such as the speed and/or pressure, of the fluid passing through at least one of (i) the underflow outlet 507 and (ii) the overflow outlet 505. Preferably the controller 550 is configured to switch between the initialisation mode and the cyclone mode based on a parameter of the fluid passing through the overflow outlet 505. When the controller 550 switches between the initialisation mode and the cyclone mode, the controller 550 may be configured to gradually increase or ramp up the flow rate of the flow of fluid through the overflow outlet 505 to a selected rate, for example from a flow rate of zero (i.e. blocked) to the selected flow rate. This may be desirable so as not to create any sudden/destabilising perturbations to the system which may result in the cyclone collapsing.

[0122] FIG. 6 shows another example separating system 600 of embodiments of the disclosure, and is similar to the system described above with reference to FIG. 1 with like reference numbers indicating similar or the same entities. FIG. 6 shows an example separating system 600 of embodiments of the disclosure. The system 600 comprises a separation vessel 601 having a fluid inlet 603, an underflow outlet 607 and an overflow outlet 605. The separation vessel 601 is conical in shape to enable the formation of a cyclone therewithin. The fluid inlet 603 is proximate to the overflow outlet 605 and configured to direct fluid into the separation vessel transverse to and eccentric to the longitudinal axis of the conical separation vessel 601. The underflow outlet 607 and overflow outlet 605 are coaxial with the longitudinal axis of the conical separation vessel 601.

[0123] In the example shown in FIG. 6, the fluid inlet 603 is coupled to a feed vessel 650. The overflow outlet 605 is coupled to a waste vessel 625 via an overflow outlet fluid control means 611 and a waste line 627. The overflow outlet fluid control means 611 is a fluid resistor. The underflow outlet 607 is also coupled to the feed vessel 650 via feed line 652. In the example shown the feed vessel 650 also comprises an input line 670 and optional valve 690. The feed vessel 650 also comprises compressed gas feed 609, which the skilled person may consider to be a fluid inlet control means as it is operable to control the flow of fluid through the fluid inlet 603.

[0124] In some examples the system 600 also comprises a controller (not shown, but an example of which is described above with reference to FIG. 5) for controlling the system 600, and in particular for controlling the compressed gas feed 609 and the overflow outlet fluid control means 611.

[0125] In the example shown in FIG. 6, which may be used for example for perfusion of biological cells in cell suspensions, the waste vessel 625 can be used for removing less dense fluid (such as cell media) separated by a cyclone formed in the separation vessel 601. Any higher density particles (such as cells) would separate out via the underflow outlet 607 and be recycled back into the feed vessel 650, whereas the less dense fluid (such as the cell media) would separate out via the overflow outlet 605 and into the waste vessel 625. The input line 670 may be used to replenish any fluid (such as cell media) removed to the waste vessel 625.

[0126] The compressed gas feed 609 is operable to control the flow of fluid into the separation vessel 601 though the fluid inlet 603. The overflow outlet fluid control means 611 is operable to control the flow of fluid through the overflow outlet 605. Controlling the flow of fluid through the fluid inlet 603 and the overflow outlet 605 may thus control the formation and functioning of a cyclone in the separation vessel 601.

[0127] In use, a fluid (for example a cell suspension containing viable cells) is fed into the separation vessel 601 transverse to and eccentric to the longitudinal axis of the separation vessel 601 from the feed vessel 650 via the fluid inlet 603. The compressed gas feed 609 is controlled to control the pressure (and thereby flow rate) of fluid fed into the separation vessel 601. The flow of fluid (such as the flow rate and/or pressure) through the overflow outlet 605 is also controlled by operating the overflow outlet fluid control means 611. Controlling the compressed gas feed 609 and/or the overflow outlet fluid control means 611 can therefore control the formation of the cyclone in the separation vessel 601.

[0128] Preferably the flow of fluid through the fluid inlet 603 and the overflow outlet 605 is controlled by controlling the compressed gas feed 609 and/or the overflow outlet flow control means 611 such that the flow rate of fluid through the underflow outlet 607 is greater than the flow rate of fluid through the overflow outlet 605.

[0129] Once a cyclone is established in the separation vessel 601, in the example of the system 600 being used for cell perfusion, cells may separate out from the separation vessel 601 via the underflow outlet 607 and be fed back (i.e. recycled) into feed vessel 650 via input line 652. Waste media may separate out from the separation vessel 601 and be extracted by the overflow outlet fluid control means 611 via the overflow outlet 605 and into waste vessel 625.

[0130] As with the other examples described above, the degree to which fluid is separated out into the waste vessel 625 may be determined based on a parameter of the fluid and/or time. For example, operation of the overflow outlet fluid control means 611 may be based on a parameter of the fluid entering and/or in and/or leaving the separation vessel 601. Similarly, control of the inlet fluid control means 609 may be based on a parameter of the fluid entering and/or in and/or leaving the separation vessel 601. However, it will also be understood that the degree to which fluid is separated out from the separation vessel 601 may be based on other factors, for example at least one of: (i) levels of toxic by-products (such as lactate or ammonia) from cell metabolism reaching a selected threshold; and (ii) cell phenotype changes (for example during differentiation of pluripotent cells).

[0131] For example, if the fluid reaches a selected threshold density, such as density of cells within the fluid, (for example, as determined by turbidity), it may be determined that a selected degree of fluid should be extracted via the overflow outlet 605. Additionally or alternatively, the extraction of fluid via the overflow outlet 605 may be a continuous process, and the flow rate of fluid extracted via the overflow outlet 605 may be based on a parameter, such as the density, of fluid entering and/or in and/or leaving the separation vessel 601.

[0132] The parameter of the fluid may be determined based on fluid entering the fluid inlet 603, fluid passing through the underflow outlet 107 and/or fluid passing through the overflow outlet 605.

[0133] Additionally or alternatively, if a threshold time interval has passed it may be determined to extract a selected amount of fluid via the overflow outlet 605, for example where the volume of fluid extracted is determined based on a function of the time interval.

[0134] It will be understood that although a controller is not shown in FIG. 6, the functionality described above may be performed by a controller operable to control the compressed gas feed 609 and the overflow outlet fluid control means 611 (and also optionally valve 690). It will also be understood that the system 600 may comprise sensors coupled to, for example, the fluid inlet 603, the overflow outlet 605 and/or the underflow outlet 607, as described above with reference to FIG. 5, for sensing the parameter of the fluid discussed above. In some examples there may also be a sensor inside the separation vessel 601, in the feed vessel 650 and/or waste vessel 625.

[0135] It will also be understood that in some examples the system 600 may also comprise an optional underflow outlet fluid control means, as described above with reference to, and as shown in, FIG. 5. It will also be understood that in some examples the system 600 may only comprise one fluid control means.

[0136] The examples described above and as shown in FIGS. 1 to 6 only have one fluid inlet, however, it will be understood that in other examples the separation vessel may have a plurality of fluid inlets. Each of the plurality of fluid inlets may have a respective fluid inlet control means. Having a plurality of fluid inlets each with a respective fluid inlet control means may allow the formation of a cyclone in the separation vessel to be more easily controlled. For example, the separation vessel may have a first fluid inlet configured to feed fluid in a first direction transverse to, and eccentric to the longitudinal axis of the separation vessel on one side of the separation vessel, and a second fluid inlet configured to feed fluid in a second direction opposite to the first direction and transverse to, and eccentric to the longitudinal axis of the separation vessel on an opposing side of the separation vessel. This may be beneficial as it may reduce the asymmetry of energy input at the top of the cyclone formed in the separation vessel, which may increase the speed at which a cyclone forms in the separation vessel, and the stability of a cyclone formed in the separation vessel.

[0137] As noted above, it will also be understood that the separation vessel may comprise a plurality of underflow and/or overflow outlets (optionally with respective fluid control means) and each coupled to a tube or line with a corresponding bore or diameter matching that of the respective outlet. In some examples the plurality of underflow and/or overflow outlets may have differing diameters and may be concentric with each other—for example, if there are two overflow outlets, one with a larger bore or diameter than the other, the two overflow outlets may be concentric with each other (for example such that one sits inside the other).

[0138] Although all of the examples shown above with reference to FIGS. 1 to 6 show some form of inlet fluid control means and an outlet fluid control means, it will be understood that in some examples an inlet fluid control means is not essential. For example, a fluid suspension may be into the separation vessel under gravity if the feed vessel is positioned above the separation vessel.

[0139] FIG. 7 shows another example separating system 700 of embodiments of the disclosure, and is similar to the system described above with reference to FIG. 1 with like reference numbers indicating similar or the same entities. FIG. 7 shows an example separating system 700 of embodiments of the disclosure. The system 700 comprises a separation vessel 701 having a fluid inlet 703, an underflow outlet 707 and an overflow outlet 705. The separation vessel 701 is conical in shape to enable the formation of a cyclone therewithin. The separation vessel 701 therefore has a longitudinal axis about an axis of symmetry of the cone. It will also be appreciated that in some examples the entire shape of the separation vessel 701 need not be conical, for example a portion of the separation vessel may be conical and another portion (such as the portion into which the fluid inlet 703 is couple) may be cylindrical.

[0140] The underflow outlet 707 is located at the bottom or apex of the conical shape of the separation vessel, at a proximal end of the longitudinal axis of the separation vessel 701 (although it will be understood that in other examples the underflow outlet 707 does not need to be at an end of the separation vessel 701, for example the underflow outlet 707 may be inset distally from the end of the separation vessel 701). The fluid inlet 703 is near the top of the conical shape of the separation vessel 701 towards a distal end of the longitudinal axis of the separation vessel 701.

[0141] In the example shown in FIG. 7, the overflow outlet 705 is coupled to a tube 710 that extends through the bottom of, or proximal end of, the separation vessel 701 coaxial with the underflow outlet 707 and up inside the separation vessel 701 parallel with and coaxial with the longitudinal axis of the separation vessel 701 (although it will be understood that in other examples the tube 710 coupled to the overflow outlet 705 need not extend coaxial with the longitudinal axis of the separation vessel 701 but may be eccentric to or offset from the longitudinal axis of the separation vessel 701 such that it is configured to extract fluid from a different radial location relative to the longitudinal axis compared to the radial location at which the underflow outlet 707 is configured to extract fluid/material). The tube 710 supports the overflow outlet 705 such that it is located between the fluid inlet 703 and the underflow outlet 707 along the longitudinal axis of the separation vessel 701, yet nearer the fluid inlet 703 along the longitudinal axis than to the underflow outlet 707. The underflow outlet 707 and overflow outlet 705 are therefore coaxial with the longitudinal axis of the conical separation vessel 701.

[0142] In the example shown in FIG. 7, the fluid inlet 703 is coupled to a feed vessel 750. The overflow outlet 705 is coupled to a waste vessel 725 via the tube 710 coupled to an overflow outlet fluid control means 711 and a waste line 727. The overflow outlet fluid control means 711 is a pump. The underflow outlet 707 is also coupled to the feed vessel 750 via feed line 752. In the example shown the feed vessel 750 also comprises an input line 770.

[0143] In some examples the system 700 also comprises a controller (not shown, but an example of which is described above with reference to FIG. 5) for controlling the system 700, for example for controlling the overflow outlet fluid control means 711.

[0144] The fluid inlet 703 is configured to direct fluid into the separation vessel 701 transverse to and eccentric to the longitudinal axis of the conical separation vessel 701. The overflow outlet 705 is positioned within the separation vessel 701 so as to draw fluid from a region, in use, proximal to the top of a cyclone formed in the separation vessel 701 (wherein the top of the cyclone may be defined as the portion of the cyclone with the greatest diameter).

[0145] The example system shown in FIG. 7, similar to the example shown in FIG. 1, may be used for example for perfusion of biological cells in cell suspensions. In this example, the waste vessel 725 can be used for removing fluid (such as cell media) or particles of lower mass, separated by a cyclone formed in the separation vessel 701. Any higher mass particles (such as cells) would separate out via the underfloor outlet 707 and be recycled back into the feed vessel 750, whereas the fluid (such as the cell media) would separate out via the overflow outlet 705 and into the waste vessel 725. The input line 770 may be used to replenish any fluid (such as cell media) removed to the waste vessel 725.

[0146] The inlet fluid control means 709 is operable to control the flow of fluid though the fluid inlet 703. The overflow outlet fluid control means 711 is operable to control the flow of fluid through the overflow outlet 105. Controlling the flow of fluid through the fluid inlet 703 and the overflow outlet 705 may thus control the formation and functioning of a cyclone in the separation vessel 701.

[0147] In use, a fluid (for example a cell suspension containing viable cells) is fed into the separation vessel 701 transverse to and eccentric to the longitudinal axis of the separation vessel 701 from the feed vessel 750 via the fluid inlet 703. The flow of fluid (such as the flow rate and/or pressure) through the overflow outlet 705 is also controlled by operating the overflow outlet fluid control means 711. Controlling the inlet fluid control means 709 and/or the overflow outlet fluid control means 711 can therefore control the formation of the cyclone in the separation vessel 701.

[0148] It will be appreciated that in the context of the examples described above the fluid is a liquid comprising biological material suspended in a suspension. However, it will be appreciated that embodiments described herein may be used for removing small or powdered solids from air, water, or other gases or liquids by centrifugal force.

[0149] It will be appreciated from the discussion above that the embodiments shown in the Figures are merely exemplary, and include features which may be generalised, removed or replaced as described herein and as set out in the claims. In the context of the present disclosure other examples and variations of the apparatus and methods described herein will be apparent to a person of skill in the art.