Apparatus and methods for a gas dynamic virtual nozzle

Patent metadata

Field	Value
Publication number	US-9289787-B2
Application number	US-201213680255-A
Country	US
Kind code	B2
Filing date	Nov 19, 2012
Priority date	May 28, 2010
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A nozzle for producing a liquid jet or a single-file stream of droplets of a fluid, methods using the nozzle, and an injector comprising the nozzle of the invention for providing the liquid jet or single-file stream of a fluid to a vacuum system are described.

First claim

We claim:

1. A nozzle assembly comprising:
a housing, wherein a distal end of the housing defines an outlet channel;
a capillary tube disposed within the housing, wherein a distal end of the capillary tube is tapered;
at least one bore defined by the capillary tube, wherein the at least one bore defines a capillary outlet on a side surface of the tapered distal end; and
an asperity defined substantially on an apex of the tapered distal end; wherein one of the following is true:
(a) the at least one bore comprises a single bore aligned with the central axis of the capillary tube, wherein the single bore diverges from the capillary tube's central axis; or
(b) the at least one bore is parallel to but spaced apart from the central axis of the capillary tube.

2. The nozzle assembly of claim 1 , wherein the capillary tube is substantially aligned along the axis of the outlet channel.

3. The nozzle assembly of claim 1 , wherein the at least one bore comprises a single bore aligned with the central axis of the capillary tube wherein the single bore diverges from the capillary tube's central axis.

4. The nozzle assembly of claim 1 , wherein the at least one bore is parallel to but spaced apart from the central axis of the capillary tube.

5. The nozzle assembly of claim 1 , wherein the capillary tube's tapered end is substantially conical.

6. The nozzle assembly of claim 1 , wherein the capillary tube's tapered end is substantially conical and beveled.

7. The nozzle assembly of claim 1 , wherein the capillary tube's tapered end defines a plurality of planar flats.

8. The nozzle assembly of claim 1 , wherein the capillary tube's tapered end is received in the outlet channel.

9. The nozzle assembly of claim 1 , wherein the capillary tube's tapered end is positioned upstream of the outlet channel.

10. The nozzle assembly of claim 1 , wherein the inner diameter of the housing is greater than the outer diameter of the capillary tube such that there is a coaxial space between the housing's inner wall and the capillary tube's external wall.

11. The nozzle assembly of claim 1 , wherein the housing defines a square internal cross-section.

12. A method for manufacturing the capillary tube of claim 1 :
heating the distal end of the capillary tube;
bending the distal end to a predetermined radius of curvature;
cutting the distal end at a desired distance along the radius of curvature; and
grinding a symmetrical cone onto the remaining portion of the distal end.

13. A method for manufacturing the capillary tube of claim 1 :
heating the distal end of the capillary tube until closure;
grinding the distal end into a cone; and
cutting at least one bevel into the cone.

14. A method for producing a liquid jet comprising:
providing a nozzle assembly according to claim 1 ;
injecting a first fluid into the proximal end of the housing; and
injecting a second fluid into the proximal end of the capillary tube.

15. An injector comprising:
(i) a chamber comprising a vacuum orifice and an injector orifice, wherein the chamber is adapted for use with a vacuum analysis system; and
(ii) a nozzle assembly comprising
(A) a housing, wherein a distal end of the housing defines an outlet channel;
(B) a capillary tube disposed within the housing, wherein a distal end of the capillary tube is tapered;
(C) at least one bore defined by the capillary tube, wherein the at least one bore defines a capillary outlet on a side surface of the tapered distal end; and
(D) an asperity defined substantially on an apex of the tapered distal end, wherein the outlet channel of the nozzle outputs to the chamber and is essentially aligned with the injector orifice.

16. The injector of claim 15 , wherein the chamber is adapted for use with a transmission electron microscope.

17. A nozzle assembly comprising:
a housing, wherein the housing defines a cavity enclosed on all sides with an inlet opening at a proximal end and a de Laval Nozzle at a distal end, wherein the de Laval Nozzle defines a converging-diverging channel, and wherein a housing outlet is defined within the de Laval Nozzle at the point where the converging-diverging channel is constricted;
a capillary tube disposed within the cavity of the housing such that there is a coaxial space maintained between the capillary tube and the housing, wherein a distal end of the capillary tube is optionally tapered;
at least one bore defined by the capillary tube, wherein a proximal end of the at least one bore defines a capillary inlet and a distal end of the at least one bore defines a capillary outlet, wherein the capillary outlet does not extend beyond the housing outlet; and
a first switching channel defined in the housing on a first side of a diverging section of the converging-diverging channel and a second switching channel defined in the housing on the second side of the diverging section of the converging-diverging channel, wherein the first and second switching channels are each in fluid communication with the diverging section of the converging-diverging channel;
wherein the housing further defines a first propelling channel and a second propelling channel, wherein the first and second propelling channels are each disposed substantially perpendicular to the coaxial space and are in fluid communication with the coaxial space.

18. The nozzle assembly of claim 17 , wherein the housing outlet has a rectangular cross-section.

19. The nozzle assembly of claim 17 , wherein the first propelling channel and the second propelling channel are on opposing sides of the housing.

20. A method for producing a liquid jet comprising:
providing a nozzle assembly according to claim 17 ;
injecting a first fluid into the first and the second propelling channels; and
injecting a second fluid into the capillary inlet.

21. The method for producing a liquid jet of claim 20 , further comprising:
operating at subsonic flow by maintaining an upstream-to-downstream pressure ratio in the converging-diverging channel in the range of about 1.03 to about 1.89.

22. The method for producing a liquid jet of claim 20 , wherein the first fluid is helium gas.

23. The method for producing a liquid jet of claim 20 , further comprising:
producing a liquid jet following a boundary layer of a first side of a diverging section of a converging-diverging channel;
injecting a first puff of air into a first switching channel; and
in response to the first puff of air, switching the liquid jet to a boundary layer of a second side of the diverging section of the converging-diverging channel.

24. The method for producing a liquid jet of claim 23 , further comprising:
injecting a second puff of air into a second switching channel; and
in response to the second puff of air, switching the liquid jet to the boundary layer of the first side of the diverging section of the converging-diverging channel.

25. The method for producing a liquid jet of claim 20 , wherein the diverging section of the converging-diverging channel is maintained at atmospheric pressure.

26. The method for producing a liquid jet of claim 20 , further comprising:
operating the diverging section of the converging-diverging channel under vacuum; and
in response to operating under vacuum, producing a liquid jet substantially centered between the first side and the second side of the diverging section of the converging-diverging chann

Assignees

• Univ Arizona

Inventors

• Doak R Bruce
• Spence John
• Weierstall Uwe
• Deponte Daniel P

Classifications

• B01L2300/0838

  Capillaries · CPC title

• B01L2200/12

  Specific details about manufacturing devices · CPC title

• G01N23/2204

  Specimen supports therefor; Sample conveying means therefore · CPC title

• B05B7/04

  with arrangements for mixing liquids or other fluent materials before discharge (mixing in general B01F, e.g. B01F25/00; mixing valves F16K11/00) · CPC title

• H01J49/165

  Electrospray ionisation · CPC title