Curtain flow design for optical chambers
Various embodiments include systems and apparatuses for reducing contamination levels within optical chambers of particle-detection instruments. In one embodiment, an apparatus to reduce contamination within an optical chamber of a particle-detection instrument is described. The apparatus includes a plenum chamber to at least partially surround an aerosol-focusing nozzle of the particle-detection instrument and accept a filtered gas flow. A curtain-flow concentrating nozzle is coupled to the plenum chamber to produce a curtain flow into the optical chamber to substantially surround an aerosol flow. Other methods and systems are disclosed.
1. An apparatus to reduce contamination within an optical chamber of a particle-detection instrument, the apparatus comprising:
a plenum chamber to at least partially surround an aerosol-focusing nozzle of the particle-detection instrument, the plenum chamber to accept a filtered gas flow; and
a curtain-flow concentrating nozzle coupled to an output of the plenum chamber to produce a curtain flow into the optical chamber to substantially surround an aerosol flow, the filtered gas flow being configured to be introduced tangentially into the plenum chamber to produce a swirling movement of the filtered gas flow in the plenum chamber.
2. The apparatus of claim 1 , further comprising an open area coupled to an output of the curtain-flow concentrating nozzle and at least partially surrounding the aerosol-focusing nozzle.
3. The apparatus of claim 2 , wherein a combination of the plenum chamber, the curtain-flow concentrating nozzle, and the open area are arranged to provide a clean sheath of airflow around the aerosol flow.
4. The apparatus of claim 2 , wherein a combination of the plenum chamber and the curtain-flow concentrating nozzle is to substantially equalize flow pressure such that the curtain flow is distributed substantially evenly around an upper portion of the aerosol-focusing nozzle before passing from an outlet of the curtain-flow concentrating nozzle into the open area surrounding the upper portion, through the outlet.
5. The apparatus of claim 1 , wherein the plenum chamber and the curtain-flow concentrating nozzle are at least partially annular around an upper portion of the aerosol-focusing nozzle.
6. The apparatus of claim 1 , wherein the plenum chamber and the curtain-flow concentrating nozzle have a toroidal shape.
7. The apparatus of claim 1 , wherein the curtain flow is to be supplied from the curtain-flow concentrating nozzle by a continuous single slit on an outlet of the curtain-flow concentrating nozzle.
8. The apparatus of claim 1 , wherein the curtain flow is to be supplied from the curtain-flow concentrating nozzle by a series of slits on an outlet of the curtain-flow concentrating nozzle.
9. The apparatus of claim 8 , wherein the series of slits is selected from at least one shape including circular slits and elongated slits.
10. The apparatus of claim 1 , wherein the contamination includes at least one type of contamination including particle contamination and working-fluid vapor contamination.
11. An apparatus to reduce contamination within a p article-detection instrument, the apparatus comprising a curtain-flow concentrating nozzle coupled to accept a filtered gas flow and produce a curtain flow into an optical chamber of the particle-detection instrument, the curtain flow to substantially surround a particle-laden aerosol flow within the particle-detection instrument, the curtain flow being configured to be introduced tangentially with reference to the particle-laden aerosol flow to produce a swirling movement of the curtain flow.
12. The apparatus of claim 11 , further comprising a plenum chamber coupled between the filtered gas flow and the curtain-flow concentrating nozzle.
13. The apparatus of claim 12 , wherein the plenum chamber to at least partially surround the aerosol-focusing nozzle of the particle-detection instrument.
14. The apparatus of claim 12 , wherein the tangentially-introduced curtain flow is also introduced at an angle with reference to a circumferential direction of the plenum chamber, to produce the swirling movement of the curtain flow in the plenum chamber.
15. The apparatus of claim 11 , wherein the contamination includes at least one type of contaminant selected from contaminant types including particle contamination and working fluid vapor contamination.
16. The apparatus of claim 11 , wherein the curtain flow is to be supplied from the curtain-flow concentrating nozzle by a continuous single slit on an outlet of the curtain-flow concentrating nozzle.
17. The apparatus of claim 11 , wherein the curtain flow is to be supplied from the curtain-flow concentrating nozzle by a series of slits on an outlet of the curtain-flow concentrating nozzle.
18. The apparatus of claim 17 , wherein the series of slits is selected from at least one shape including square slits, rectangular slits, and elliptical slits.
19. The apparatus of claim 11 , wherein curtain flow is further configured to at least substantially surround working-fluid vapors within the particle-detection instrument.
20. An apparatus to reduce contamination in a particle-detection instrument, the apparatus comprising:
a plenum chamber surrounding an aerosol-focusing nozzle of the particle-detection instrument, the plenum chamber to accept a filtered gas flow;
a curtain-flow concentrating nozzle coupled to an outlet of the plenum chamber to produce a curtain flow into the optical chamber to substantially surround an aerosol flow, the filtered gas flow being configured to be introduced tangentially into the plenum chamber to produce a swirling movement of the filtered gas flow in the plenum chamber; and
an open area coupled to an output of the curtain-flow concentrating nozzle and at least partially surrounding the aerosol-focusing nozzle to reduce at least one of particle contaminants and working-fluid vapors.
21. The apparatus of claim 20 , wherein the plenum chamber and the curtain-flow concentrating nozzle have a toroidal shape.
22. The apparatus of claim 20 , wherein the curtain flow is to be supplied from the curtain-flow concentrating nozzle by a continuous single slit on an outlet of the curtain-flow concentrating nozzle.
23. The apparatus of claim 20 , wherein the curtain flow is to be supplied from the curtain-flow concentrating nozzle by a series of slits on an outlet of the curtain-flow concentrating nozzle.