Particle separating apparatus and method

• US 5,819,948 A
• Filed: 08/21/1997
• Issued: 10/13/1998
• Est. Priority Date: 08/21/1997
• Status: Expired due to Term

• Current Assignee: Washington University In St Louis
• Original Assignee: Washington University In St Louis
• Inventors: Van den Engh, Gerrit J.
• Primary Examiner(s): Valenza, Joseph E.
• Assistant Examiner(s): DILLON JR, JOSEPH A
• Application Number:
  US08/918,695
• Time in Patent Office: 418 Days
• Field of Search: 73/865.5, 324/71.4, 356/441, 356/442
• US Class Current: 209/158
• CPC Class Codes: B01L 3/0268 using pulse dispensing or spraying, eg. inkjet type, piezo actuated ejection of droplets from capillaries
• CPC Class Codes: G01N 15/10 Investigating individual particles
• CPC Class Codes: Y10S 209/92 Vibratory feed conveyor
• CPC Class Codes: Y10S 209/921 Reciprocating or oscillating feed conveyor

Abstract

A disposable first tube (68) extends axially through, and is detachably connected to, an annular main body (10'"'"'). An input piezo electric element (38) is attached to a first end of the tubular main body (10'"'"'). A second, sensor piezo electric element (40) is attached to the opposite end of the main body (10'"'"'). A nozzle (20'"'"') having a nozzle passageway (110) and a discharge opening (112) is detachably secured to an outlet end of the first tube (68). A second tube (102) within the first tube (68) delivers a core liquid to the nozzle passageway (110). A sheath liquid is delivered through a space in the first tube (68) surrounding the second tube (102). The nozzle passageway (110) forms the core and sheath liquids into a small diameter jet stream. Electrical energy is delivered to the input piezo electric element (38), to vibrate the nozzle (20'"'"') and break the jet stream into droplets. The sensor element (40) determines the amplitude of vibration at the nozzle (20'"'"') and delivers this information to a control circuit that adjusts the electrical energy input to the input piezo electric element (38) for maintaining a desired amplitude of vibration at the nozzle (20'"'"'). The frequency of vibration is determined by the length of the main body (10'"'"') between the two piezo electric elements (38, 40). The first and second tubes (68, 102) are disposable and are replaced after a use rather than being cleaned and sterilized.

Claims

1. A particle separator, comprising:

an axially elongated, tubular main body including a central axial opening and first and second ends;

a nozzle at the second end of the tubular main body having a central nozzle passageway and a discharge opening;

a sheath liquid passageway connected to said nozzle passageway;

a core liquid passageway in said sheath liquid passageway, said core liquid passageway having a discharge opening discharging into the nozzle passageway; and

an annular input piezo electric element connected to the first end of said main body, about the central axial opening, and adapted to vibrate said main body when excited by electrical energy, whereby said main body will function as a mechanical oscillator, with the frequency of oscillation being a function of the length of the main body.

2. A particle separator according to claim 1 wherein the central axial opening in the main body provides the sheath liquid passageway.

3. A particle separator according to claim 1, comprising a separate tube extending axially through the central axial opening in said main body, said tube being connected to the main body and defining the sheath liquid passageway.

4. A particle separator according to claim 3, wherein the separate tube is detachably connected to the main body and is a disposable component of the separator.

5. A particle separator according to claim 4, comprising a core liquid delivery tube within said sheath liquid passageway, said tube also being a disposable component of the separator.

6. A particle separator according to claim 1, wherein the piezo electric element is a thin, annular member that is bonded to the first end of the tubular main body.

7. A particle separator according to claim 1, further comprising a second piezo electric element connected to the second end of the tubular main body.

8. A particle separator according to claim 7, wherein the second piezo electric element is a thin and annular member that and is bonded to the second end of the tubular main body.

9. A particle separator according to claim 1, wherein the tubular main body has a tapered section between its first and second ends.

10. A particle separator according to claim 9, wherein the tubular main body includes a light cylindrical portion between its first end and the tapered portion.

11. A particle separator according to claim 9, wherein the tubular main body includes a right cylindrical portion between the tapered portion and its second end.

12. A particle separator according to claim 9, further comprising a second piezo electric element connected to the tubular main body.

13. A particle separator according to claim 12, wherein the second piezo electric element is an annular member and is bonded to the second end of the tubular main body.