Cross-flow assembly and method for membrane emulsification controlled droplet production

Abstract

There is described 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 (2) provided with a first inlet (3) at a first end (4); an emulsion outlet (5); and a second inlet (7), 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 (2); 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.

Claims

1. 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 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; and wherein the emulsion outlet is generally at a second end of the tubular sleeve; and wherein the inlet and outlet ends of the outer sleeve are provided with a seal assembly comprising a tubular ferrule provided with a flange at each end.

2. A cross-flow apparatus according to claim 1 wherein the membrane pores are laser drilled.

3. A cross-flow apparatus according to claim 2 wherein the membrane pores are substantially uniform in pore diameter, pore shape and pore depth.

4. A cross-flow apparatus according to claim 3 wherein the membrane pores are generally uniformly spaced.

5. A cross-flow apparatus according to claim 2 wherein the pores have a diameter of from about 1 ?m to about 100 ?m.

6. A cross-flow apparatus according to claim 2 wherein the shape of the pores is substantially tubular.

7. A cross-flow apparatus according to claim 2 wherein the interpore distance is from about 1 ?m to about 1,000 ?m.

8. A cross-flow apparatus according to claim 2 wherein the surface porosity of the membrane may be from about 0.001% to about 20% of the surface area of the membrane.

9. A cross-flow apparatus according to claim 2 wherein the pores are in a patterned arrangement.

10. A cross-flow apparatus according to claim 9 wherein the patterned arrangement is a square, triangular, linear, circular or rectangular arrangement.

11. A cross-flow apparatus according to claim 10 wherein the patterned arrangement is a square arrangement.

12. A cross-flow apparatus according to claim 1 wherein the membrane comprises a material selected from glass; ceramic; metal; polymer/plastic or silicon.

13. A cross-flow apparatus according to claim 12 wherein the membrane comprises a metal.

14. A cross-flow apparatus according to claim 13 wherein the metal is stainless steel.

15. A cross-flow apparatus according to claim 1 wherein the furcation plate is a bi-furcation plate or a tri-furcation plate.

16. A cross-flow apparatus according to claim 15 wherein the furcation plate is a tri-furcation plate.

17. A cross-flow apparatus according to claim 15 wherein the number of orifices provided in the insert is from 2 to 6.

18. A cross-flow apparatus according to claim 17 wherein the number of orifices provided in the insert is three.

19. A cross-flow apparatus according to claim 15 wherein the chamfered region on the insert comprises a shallow chamfer.

20. A cross-flow apparatus according to claim 1 wherein the apparatus is suitable for preparing droplets with a coefficient of variation of from about 5% to about 50%.

21. A cross-flow apparatus according to claim 1 wherein the apparatus is capable of a throughput of from 1 to 10.sup.6 LMH.

22. A cross-flow apparatus according to claim 1 wherein a first flange located at the end adjacent to the outer sleeve (when coupled) is provided with a circumferential internal recess which acts as a seat for an O-ring seal.

23. A cross-flow apparatus according to claim 22 wherein the O-ring seal allows a loose fit as the membrane slides through the O-ring.

24. A cross-flow apparatus according to claim 1 wherein the tubular membrane is located centrally within the outer sleeve, such that the spacing between the membrane and the sleeve comprises an annulus, of equal or substantially equal dimensions at any point around the tubular membrane.

25. A cross-flow apparatus according to claim 24 wherein the spacing is from about 0.05 to about 10 mm.

26. A cross-flow apparatus according to claim 1 wherein the insert is tapered.

27. A cross-flow apparatus according to claim 1 wherein the apparatus includes an insert and the tubular membrane is located centrally within the outer sleeve, such that the spacing between the membrane and the insert comprises an annulus, of equal or substantially equal dimensions at any point around the insert.

28. A cross-flow apparatus according to claim 1 wherein the cross-flow apparatus comprises a plurality of tubular membranes wherein the plurality of membranes is grouped as a cluster of membranes positioned alongside each other and wherein each membrane has an insert located inside it.

29. A cross-flow apparatus according to claim 28 wherein each membrane has an insert located inside it.

30. A cross-flow apparatus according to claim 28 wherein a plurality of membranes is grouped as a cluster of membranes positioned alongside each other.

31. A cross-flow apparatus according to claim 1 wherein the seal assembly on the inlet and outlet ends of the outer sleeve are the same.

Description

(1) The present invention will now be described by way of example only, with reference to the accompanying figures in which:

(2) FIG. 1(a) is a cross-sectional view of a tubular sleeve and FIG. 1(b) is a plan view of the sleeve;

(3) FIG. 2 is a perspective view of an insert;

(4) FIG. 3 is a cross-sectional view along line B-B;

(5) FIG. 4 is a close-up view of an end of the insert;

(6) FIG. 5(a) is a perspective view of a seal ferrule and FIG. 5(b) is a cross-sectional view of a seal ferrule;

(7) FIG. 6 is a perspective view of a disassembled cross-flow apparatus;

(8) FIG. 7 is a cross-sectional view of a tubular sleeve with a membrane and insert in situ; and

(9) FIG. 8 is a close-up view of an end of the tubular sleeve with a membrane and insert in situ.

(10) Referring to FIGS. 1(a) and 1(b), a cross-flow apparatus 1 for, producing an emulsion or dispersion, comprises an outer tubular sleeve 2 provided with a first inlet 3 at a first end 4, an emulsion outlet 5 at a second end 6; and a second inlet 7 distal from and inclined relative to the first inlet 3. Each of the ends 4 and 6 is provided with a flange 8 and 9.

(11) Referring to FIGS. 2 to 4, an insert 10 comprises a longitudinal rod 11 with first and second hollow chamfered ends 12 and 13. Each of the chamfered ends 12 and 13 comprises a chamfered surface 14 and 15 and each chamfered surface is provided with three orifices 16a and 16b (16c not shown); and 17a, 17b and 17c. Internally each chamfered 12 and 13 end is provided with a trifurcation plate 18a (not shown) and 18b which comprises fins 19a, 19b and 19c.

(12) Referring to FIGS. 5(a) and 5(b), a seal ferrule 20, is adapted to be positioned at each end 4 and 6 of the tubular sleeve 2. The seal ferrule 20 comprises a cylinder 21 with a flange 22 at one end 23 and a protrusion 24 which acts a seat for an O-ring seal 25 (not shown). In use the flange 23 is adapted to mate with flanges 8 and 9 of the sleeve 2.

(13) Referring to FIG. 6, a disassembled cross-flow apparatus 1 comprises an outer tubular sleeve 2, a membrane 26 and an insert 10. Each end 4 and 6 of the sleeve 2 is provided with a seal ferrule 20 and 20a and an O-ring seal 25 and 25a.

(14) Referring to FIGS. 7 and 8, an assembled cross-flow apparatus 1 comprises an outer sleeve 2, with a membrane 26 located inside the sleeve 2; and an insert 10 located inside the membrane 26. The insert 10 is located centrally within membrane 26 and each end 26a and 26b of the membrane 26 is sealed by an O-ring seal 25 and 25a which is compressed by the seal ferrule 20 and 20a .

(15) In use, in the embodiment shown, a continuous phase will pass through the orifices 16a and 16b (16c not shown) at the inlet end 4 of the sleeve 2 and through a gap 27 between the insert 2 and the membrane 26. A disperse phase will pass through the branched second inlet 7 and through the membrane 26 into gap 27 to contact with the continuous phase to form an emulsion or dispersion. Said emulsion or dispersion will flow out of the cross-flow apparatus 1 at the outlet end 6.

(16) It will be understood by the person skilled in the art that this is one embodiment of the present invention. Although not illustrated here, it will be understood that the flow may be may be in the opposite direction to the described, for example the disperse phase can be introduced at inlet end of the sleeve and the continuous phase introduced at the second branched inlet. Such additional embodiments should be deemed to be within the scope of the present invention.