MEMBRANE EMULSIFICATION APPARATUS WITH REFINER AND METHOD OF PREPARING A REFINED EMULSION

Abstract

Membrane Emulsification Apparatus with Refiner There is described a membrane emulsification apparatus for dispersing a first phase in a second phase, comprising: •a membrane defining a plurality of apertures connecting a first volume on a first side of the membrane to a second volume on a second, different, side of the membrane, the apparatus being arranged to receive a first phase containing a liquid in the first volume and to receive a second phase in the second volume the apparatus being adapted to generate an emulsion through egression of the first phase into the second phase via the plurality of apertures; •the apparatus also comprising a refiner (1) arranged to receive the emulsion from the membrane; and wherein said refiner comprises an inlet (4/5) and an outlet (5/4) wherein an opening (8) adapted to converge flow of the emulsion and to break up droplets of the emulsion into a refined emulsion is located between the inlet and the outlet.

Claims

1. A membrane emulsification apparatus for dispersing a first phase in a second phase, comprising: a membrane defining a plurality of apertures connecting a first volume on a first side of the membrane to a second volume on a second, different, side of the membrane, the apparatus being arranged to receive a first phase containing a liquid in the first volume and to receive a second phase in the second volume the apparatus being adapted to generate an emulsion through egression of the first phase into the second phase via the plurality of apertures; the apparatus also comprising a refiner arranged to receive the emulsion from the membrane; and wherein said refiner comprises an inlet and an outlet wherein an opening adapted to converge flow of the emulsion and to break up droplets of the emulsion into a refined emulsion is located between the inlet and the outlet; wherein the opening is adjustable and the opening comprises adjustment means, such that the refiner is tunable by adjustment of the opening.

2.-11. (canceled)

12. Membrane emulsification apparatus according to claim 1 wherein the adjustment means in the tunable refiner comprises a differential screw.

13. Membrane emulsification apparatus according to claim 12 wherein the differential screw comprises a spindle with two external screw threads of differing thread pitch.

14. Membrane emulsification apparatus according to claim 12 wherein the differential screw comprises a spindle with two external screw threads are generally congruous.

15. Membrane emulsification apparatus according to claim 12 wherein the differential screw comprises a spindle with two external screw threads of differing handedness.

16. Membrane emulsification apparatus according to claim 12 wherein nuts are located around two external screw threads of the differential screw.

17. Membrane emulsification apparatus according to claim 13 wherein the first end of the spindle, adjacent the refiner opening, is smaller than the second end of the spindle, which is distal to the refiner opening.

18. Membrane emulsification apparatus according to claim 17 wherein the distal end of the spindle is provided with a first external thread, the diameter of which is wider than that of the end of the spindle adjacent the opening, which is provided with a second external thread.

19.-24. (canceled)

25. Membrane emulsification apparatus according to claim 1 wherein the refiner is integral to the membrane.

26. Membrane emulsification apparatus according to claim 1 wherein the adjustable opening comprises a refiner plug adjacent the opening, such that movement of the insert rod closer to the opening reduces the size of the opening.

27. Membrane emulsification apparatus according to claim 26 wherein the end of the insert rod adjacent to the opening comprises a frusto conical member with a terminal protrusion.

28. Membrane emulsification apparatus according to claim 27 wherein the terminal protrusion comprises a flat end surface.

29. Membrane emulsification apparatus according to claim 26 wherein the insert rod is adapted to simulate multiple passes of the emulsion through the opening.

30. (canceled)

31. (canceled)

32. Membrane emulsification apparatus according to claim 1 wherein the apparatus is used in a continuous mode.

33. Membrane emulsification apparatus according to claim 32 wherein the refiner comprises multiples inlets and/or multiple outlets.

34.-45. (canceled)

46. A method of preparing a refined emulsion, said method comprising using a membrane emulsification apparatus according to claim 1.

47. A method of preparing a refined emulsion according to claim 46 wherein the method comprises providing a first phase to the first volume of the apparatus; providing a second phase to the second volume of the apparatus; causing the egression of the first phase into the second phase via a plurality of apertures in a membrane to preparing an emulsion; passing the emulsion through an inlet of a refiner and converging the flow of the emulsion through an adjustable opening to break up droplets of the emulsion into a refined emulsion.

48. A method of preparing a refined emulsion according to claim 46 wherein the membrane emulsification apparatus for dispersing a first phase in a second phase, comprises: a membrane defining a plurality of apertures connecting a first volume on a first side of the membrane to a second volume on a second, different, side of the membrane, the apparatus being arranged to receive a first phase containing a liquid in the first volume and to receive a second phase in the second volume the apparatus being adapted to generate an emulsion through egression of the first phase into the second phase via the plurality of apertures; the apparatus also comprising a tunable refiner arranged to receive the emulsion from the membrane; and wherein said refiner comprises an inlet and an outlet wherein an adjustable opening adapted to converge flow of the emulsion and to break up droplets of the emulsion into a refined emulsion is located between the inlet and the outlet.

49.-53. (canceled)

54. A method of preparing a refined emulsion according to claim 46 wherein the apparatus is arranged to receive a first phase containing a liquid in the first volume and to receive a second phase in the second volume; the apparatus being adapted to generate an emulsion through egression of the first phase into the second phase via the plurality of apertures.

55. A method of preparing a refined emulsion according to claim 46 wherein the apparatus is arranged so that flow of the second phase in the second volume creates a shear field at the area of egression of the first phase, the shear field being in a direction substantially perpendicular to the direction of egression of the first phase.

56. A method of preparing a refined emulsion according to claim 46 wherein the membrane is tubular in shape and comprises a first end and a second end; wherein the first end is for receiving the second phase; and the refiner is coupled to the second end.

57.-78. (canceled)

79. A method of preparing a refined emulsion according to claim 46 wherein the apparatus is used in a continuous mode.

80. A method of preparing a refined emulsion according to claim 79 wherein the refiner comprises multiples inlets and/or multiple outlets.

81.-88. (canceled)

89. A method of preparing a refined emulsion, said method comprising using a membrane emulsification apparatus for dispersing a first phase in a second phase, wherein the membrane emulsification apparatus comprises a cross-flow apparatus for producing an emulsion or dispersion by dispersing a first phase in a second phase; said cross-flow apparatus comprising: an outer tubular sleeve provided with a first inlet at a first end; an emulsion outlet; and a second inlet, distal from and inclined relative to the first inlet; a tubular membrane provided with a plurality of pores and adapted to be positioned inside the tubular sleeve; and optionally an insert adapted to be located inside the tubular membrane, said insert comprising an inlet end and an outlet end, each of the inlet end and an outlet end being provided with chamfered region; the chamfered region is provided with a plurality of orifices and a furcation plate; the apparatus also comprising a refiner arranged to receive the emulsion from the membrane and wherein said refiner comprises an inlet and an outlet wherein an opening adapted to converge flow of the emulsion and to break up droplets of the emulsion into a refined emulsion is located between the inlet and the outlet; wherein the refiner is an adjustable refiner.

90.-95. (canceled)

Description

[0059] The present invention will now be described by way of example only, with reference to the accompanying figures in which:

[0060] FIG. 1(a)-(c) illustrates the membrane emulsification apparatus refiner of the invention;

[0061] FIG. 2(a)-(c) illustrates a refiner plug;

[0062] FIGS. 3(a) and (b) illustrates an adjustment means, as a differential screw;

[0063] FIG. 4(a)-(e) illustrates refined emulsions formed according to the invention;

[0064] FIG. 5(a) illustrates refined emulsions formed at 5 bar with 1 pass at 3 L/min;

[0065] FIG. 5(b) is an overlay plot of Differential Volume (volume v particle diameter) (measured by LS Particle Size Analyser);

[0066] FIG. 6(a) illustrates refined emulsions formed at 5 bar with 1 pass at 200 mL/min;

[0067] FIG. 6(b) is an overlay plot of Differential Volume (volume v particle diameter) (measured by LS Particle Size Analyser);

[0068] FIG. 7(a) illustrates refined emulsions formed at 30 bar with 3 passes at 3 L/min;

[0069] FIG. 7(b) is an overlay plot of Differential Volume (volume v particle diameter) (measured by LS Particle Size Analyser);

[0070] FIG. 8(a) illustrates refined emulsions formed at 30 bar with 1 pass at 200 mL/min;

[0071] FIG. 8(b) is an overlay plot of Differential Volume (volume v particle diameter) (measured by LS Particle Size Analyser);

[0072] FIGS. 9(a)-(d) illustrate a fixed refiner with multiple stages;

[0073] FIGS. 10(a) and (b) are cross-sections of a fixed refiner with multiple stages;

[0074] FIGS. 11(a)-(c) illustrate a single inlet/outlet port for use with a fixed refiner; FIGS. 12(a)-(c) illustrate a multiple inlet/outlet port for use with a fixed refiner;

[0075] FIG. 13 illustrates the change of particle diameters using multiple passes of a refiner at 5 bar input pressure at a flow rate of 3 Litres/min.;

[0076] FIG. 14 illustrates the change of particle diameters using multiple passes of a refiner at 5 bar input pressure at a flow rate of 200 ml/min.;

[0077] FIG. 15 illustrates the change of particle diameters using multiple passes of a refiner at 30 bar input pressure at a flow rate of 200 ml/min.; and

[0078] FIG. 16 illustrates the change of particle diameters using multiple passes of a refiner at 30 bar input pressure at a flow rate of 3 Litres/min.

[0079] In the figures herein the following numbering has been used:

TABLE-US-00001  1 membrane emulsification refiner apparatus  2 tunable refiner  3 first end  4 outlet/inlet  5 inlet/outlet  6 refiner plug  7 differential screw  8 opening  9 refiner plug body  9a and 9b circumferential grooves 10 first end of refiner plug body 11 frusto conical member 12 terminal protrusion 13 flat end surface 14 second end of refiner plug 15 internal longitudinal chamber 16 internal screw thread 17 second end of tunable refiner 17a internal longitudinal chamber 18 internal screw thread 19 differential screw body 20 spindle 21 body external screw thread 22 spindle external screw thread 23 screw turn handle 24 fixed refiner 24(a) sanitary gasket groove 25(c-e) multiple stages 26 inlet/outlet 27 single inlet/outlet orifice 28 outlet/inlet 29 single outlet/inlet orifice 30 stage inlet/outlet 31 stage opening/gap 31(a-c) stage plug 32(a-c) stage outlet/inlet 33 refiner single inlet/outlet port 34 refiner single orifice 35 refiner inlet/outlet port 36 radially space orifices

[0080] Referring to FIGS. 1(a)-(c), 2(a)-(c), 3(a) and 3(b); membrane emulsification apparatus 1 comprises a membrane emulsifier (not shown) and a tunable refiner 2. At a first end 3, the tunable refiner 2 comprises an inlet 5, an outlet 4, a refiner plug 6 and a differential screw 7. Between the inlet 5 and outlet 4 an opening 8 is located.

[0081] The refiner plug 6 comprises a body 9; which at a first end 10, adjacent the opening 8, comprises a frusto conical member 11 with a terminal protrusion 12. The terminal protrusion 12 comprises a flat end surface 13, such that the flat end surface 13 substantially abuts the opening 8. The body 9 of the refiner plug 6 may be provided with one or more circumferential grooves 9a and 9b. The one or more circumferential grooves 9a and 9b are each adapted to house a seal, e.g. in the form of an O-ring (not shown).

[0082] A second end 14 of the refiner plug 6, distal from the opening 8, is provided with an internal longitudinal chamber 15. The internal longitudinal chamber 15 is provided with an internal screw thread 16.

[0083] A second end 17, the tunable refiner 2 is provided with an internal longitudinal chamber 17a. The internal longitudinal chamber 17a is provided with an internal screw thread 18.

[0084] The differential screw 7 comprises a body 19 and a spindle 20. The body 19 is provided with an external screw thread 21; and the spindle 20 is provided with an external screw thread 22.

[0085] External screw thread 21 of the differential screw body 19 is adapted to engage with internal screw thread 18 of the tunable refiner 2; and external screw thread 22 of the spindle 20 is adapted to engage with internal screw thread 16 of the refiner plug 6.

[0086] The differential screw 7 is provided with a turn handle 23.

[0087] In operation the opening 8 is adjustable by fine movement of the refiner plug 6 with the terminal protrusion 12 and the flat end surface 13 which substantially abuts the opening 8. A rotation of the handle 23 of the differential screw 7 translates to a fine movement of the flat end surface 13 of the terminal protrusion 12; and a fine adjustment of the opening 8.

[0088] Referring to FIG. 4 an emulsion formed by a membrane without a refiner s illustrated in FIG. 4(a). FIGS. 4(b)-4(e) illustrate refined emulsions formed from a single pass of the emulsion through the refiner. Pressure was increased by closing the gap in the opening. FIG. 4(b) illustrates a refined emulsion at 5 bar (5×10.sup.5 Pa) (refiner inlet pressure); FIG. 4(c) illustrates a refined emulsion at 11 bar (11×10.sup.5 Pa) (refiner inlet pressure); FIG. 4(d) illustrates a refined emulsion at 20 bar (2×10.sup.6 Pa) (refiner inlet pressure); and FIG. 4(e) illustrates a refined emulsion at 28 bar (2.8×10.sup.6 Pa) (refiner inlet pressure).

[0089] Referring to FIGS. 9(a)-(d), 10(a) and (b); a fixed refiner 24 is provided with multiple stages 25(c-e). The fixed refiner 24 is provided with an inlet 26, with a single orifice 27, and an outlet 28 with a single orifice 29. Each stage is provided with an annular groove or a pair of annular grooves 24(a) adapted for housing a sanitary gasket. The refiner illustrated comprises three refiner stages. However, it will be understood that the number of refiner stages may be varied and therefore the number illustrated should not be considered to be limiting.

[0090] The inlet 26 connects with a first stage 25(c) of the refiner 24 and the outlet 28 connects with a third stage 25(e) of the refiner 24. Each of stages 25(a), (b) and (c) is provided with an inlet 30 (a), (b) and (c) respectively, an opening 31 (a), (b) and (c) adjacent to plug 31 (a), and an outlet 32 (a), (b) and (c).

[0091] FIG. 10 (b) illustrates how the how the refiner can be configured to different size openings 31 are progressively larger, 0.05 mm, 0.10 mm and 0.20 mm, relative to plugs 31 (a-c). Such that, in use, an emulsion to be refined (not shown) will pass through the refiner with suitably configured stages from stage (a) to stage (c) (or from stage (c) to stage (a)) and consequently the emulsion droplets will be progressively refined. It is within the scope of the present invention for stages (a-c) to be varied. For example, if a broader size distribution is desirable then the configuration of stages (a-c) may be altered, or more or fewer stages may be included, or the size of the openings and/or the plugs may be varied.

[0092] An important aspect of the multiple stage refiner s the diameter of the inlet orifice (which may affect the velocity of an emulsion); the gap/opening adjacent the plug and/or the plug diameter (which may affect the pressure differential/velocity/shear).

[0093] Referring to FIGS. 11(a)-(c); a single inlet/outlet port 33 for use with a fixed refiner (not shown). The single inlet/outlet port 33 is provided with a single, substantially central, orifice 34.

[0094] Referring to FIGS. 12(a)-(c); an inlet/outlet port 35 is provided with a plurality of radially spaced orifices 36. The plurality of radially spaced orifices 36 ensures that flow distributes evenly around circumference of the plug 31(a-c) and the opening/gap 31.

EXAMPLE 1

[0095] Using a Beckman Coulter LS particle size analyser droplet production was carried out, starting from a large primary emulsion, varying the flow rate and the size of the adjustable opening of the refiner body and the refiner plug. The results are illustrated in Table 1.

TABLE-US-00002 TABLE 1 Flow Rate Pressure Distance (mL/min) (bar) (um) 500 5 17 500 30 7 3000 5 99 3000 30 41 7500 5 238 7500 30 101

EXAMPLE 2

[0096] Using multiple passes of a refiner at 5 bar input pressure at a flow rate of 3 Litres/min., the change of the diameter of the particles was measured using a Beckman Coulter LS particle size analyser. The results are illustrated in Table 2 and FIG. 13.

TABLE-US-00003 TABLE 2 % % % Pass D10 Change D25 D50 Change D75 D90 Change 1 1.371 2.623 6.843 15.92 24.32 2 2.381 73.66885 3.69 6.514 −4.80783 11.69 16.79 −30.9622 3 2.209 −7.22386 3.383 5.621 −13.7089 9.653 14.02 −16.4979 4 2.585 17.02128 4.052 6.972 24.03487 11.19 14.97 6.776034 5 2.627 1.624758 4.09 6.86 −1.60643 10.69 14.1 −5.81162

EXAMPLE 3

[0097] Using multiple passes of a refiner at 5 bar input pressure at a flow rate of 200 ml/min., the change of the diameter of the particles was measured using a Beckman Coulter LS particle size analyser. The results are illustrated in Table 3 and FIG. 14.

TABLE-US-00004 TABLE 3 % % % Pass D10 Change D25 D50 Change D75 D90 Change 1 1.786 4.114 11.94 21.03 30.26 — 2 2.868 60.58231 4.726 8.658 −27.4874 14 19.1 −36.8804 3 2.667 −7.00837 4.15 6.988 −19.2885 11.01 14.68 −23.1414 4 2.498 −6.33671 3.832 6.23 −10.8472 9.761 13.23 −9.87738 5 2.378 −4.80384 3.609 5.699 −8.52327 8.792 12.03 −9.07029

EXAMPLE 4

[0098] Using multiple passes of a refiner at 30 bar input pressure at a flow rate of 200 ml/min., the change of the diameter of the particles was measured using a Beckman Coulter LS particle size analyser. The results are illustrated in Table 4 and FIG. 15.

TABLE-US-00005 TABLE 4 % % % Pass D10 Change D25 D50 Change D75 D90 Change 1 0.799 1.772 3.178 5.062 7.728 2 0.754 −5.63204 1.522 2.52 −20.7048 3.696 4.844 −37.3188 3 0.66  −12.4668 1.452 2.431 −3.53175 3.567 4.687 −3.24112 4 0.774 17.27273 1.538 2.411 −0.82271 3.421 4.413 −5.84596

EXAMPLE 5

[0099] Using multiple passes of a refiner at 30 bar input pressure at a flow rate of 3 Litres/min, the change of the diameter of the particles was measured using a Beckman Coulter LS particle size analyser. The results are illustrated in Table 5 and FIG. 16.

TABLE-US-00006 TABLE 5 % % % Pass D10 Change D25 D50 Change D75 D90 Change 1 0.595 1.213 2.286 3.728 5.231 2 0.521 −12.437 1.161 2.087 −8.70516 3.163 4.206 −19.5947 3 0.481 −7.67754 1.064 1.93 −7.52276 2.857 3.74 −11.0794 4 0.451 −6.23701 1.043 1.869 −3.16062 2.726 3.524 −5.7754 5 0.433 −3.99113 1.002 1.801 −3.63831 2.603 3.344 −5.10783