SELF-CLEANING OPTICAL SENSOR

• US 20130293881A1
• Filed: 05/04/2012
• Published: 11/07/2013
• Est. Priority Date: 05/04/2012
• Status: Active Grant

• Current Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Original Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Inventors: TOKHTUEV, Eugene, OWEN, Christopher J., CHRISTENSEN, William M., SKIRDA, Anatoly
• Granted Patent: US 9,001,319 B2
• Time in Patent Office: Days
• US Class Current: 356/246
• CPC Class Codes: B08B 3/02 Cleaning by the force of jets or sprays
• CPC Class Codes: B08B 5/02 Cleaning by the force of jets, e.g. blowing-out cavities airguns or nozzles per se B05B1/005
• CPC Class Codes: G01N 2021/151 Gas blown
• CPC Class Codes: G01N 2021/6478 Special lenses
• CPC Class Codes: G01N 2021/6482 Sample cells, cuvettes
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/15 Preventing contamination of the components of the optical system or obstruction of the light path
• CPC Class Codes: G01N 21/645 Specially adapted constructive features of fluorimeters
• CPC Class Codes: G01N 21/85 Investigating moving fluids or granular solids
• CPC Class Codes: G01N 2201/0639 Sphere lens
• CPC Class Codes: G02B 27/0006 with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation G02B1/18 takes precedence; cleaning in general B08B

Abstract

An optical sensor may include a sensor head that has an optical window for directing light into a flow of fluid and/or receiving optical energy from the fluid. The optical sensor may also include a flow chamber that includes a housing defining a cavity into which the sensor head can be inserted. In some examples, the flow chamber includes an inlet port defining a flow nozzle that is configured to direct fluid entering the flow chamber against the optical window of the sensor head. In operation, the force of the incoming fluid impacting the optical window may prevent fouling materials from accumulating on the optical window.

Claims

1. An optical sensor comprising:

a sensor head that includes a first optical window, a second optical window, at least one light source, and at least one detector, wherein the at least one light source is configured to emit light through the first optical window into a flow of fluid and the at least one detector is configured to detect fluorescent emissions through the second optical window from the flow of fluid;

a flow chamber that includes a housing defining a cavity into which the sensor head is inserted, an inlet port configured to communicate the flow of fluid from outside of the cavity to an interior of the cavity, and an outlet port configured to communicate the flow of fluid from the interior of the cavity to back outside of the cavity,

wherein the inlet port defines a first fluid nozzle configured to direct a portion of the flow of fluid against the first optical window and a second fluid nozzle configured to direct a portion of the flow of fluid against the second optical window.

2. The optical sensor of claim 1, wherein the first optical window and the second optical window are positioned within a same plane, and the first fluid nozzle and the second fluid nozzle are positioned within the same plane as the first optical window and the second optical window.

3. The optical system of claim 1, wherein the first fluid nozzle defines a first fluid axis extending through a center of the first fluid nozzle, the second fluid nozzle defines a second fluid axis extending through a center of the second fluid nozzle, and the first fluid axis intersects approximately a center of the first optical window and the second fluid axis intersects approximately a center of the second optical window.

4. The optical sensor of claim 1, wherein the sensor head includes a sensor housing extending from a proximal end to a distal end, the sensor housing including an angular cutout defined by a first planar surface that intersects a second planar surface, wherein the first optical window is positioned in the first planar surface and the second optical window is positioned on the second planar surface.

5. The optical sensor of claim 4, wherein the first planar surface intersects the second planar surface to define an approximately 90 degree angle, the first optical window and the second optical window are positioned within a same plane between the proximal end and the distal end of the sensor housing, and the first fluid nozzle and the second fluid nozzle are positioned within the same plane as the first optical window and the second optical window.

6. The optical sensor of claim 4, wherein the first fluid nozzle and the second fluid nozzle project away from a wall of the flow chamber into the angular cutout.

7. The optical sensor of claim 6, wherein the first optical window is configured to project light from the at least one light source into a first region of the angular cutout, the second optical window is configured to receive optical energy from a second region of the angular cutout and direct the optical energy on the at least one photodetector, and the first fluid nozzle and the second fluid nozzle project into a third region of the angular cutout between the first region and the second region.

8. The optical sensor of claim 7, wherein the first optical window and the second optical window each comprise a ball lens.

9. A method comprising:

directing fluid through a first fluid nozzle of a flow chamber against a first optical window of a sensor head; and

directing fluid through a second fluid nozzle of the flow chamber against a second optical window of the sensor head,

wherein the sensor head includes at least one light source configured to emit light through the first optical window into a flow of fluid and at least one detector configured to receive optical energy through the second optical window from the flow of fluid.

10. The method of claim 9, wherein the first optical window and the second optical window are positioned within a same plane, and directing fluid through the first fluid nozzle comprises directing fluid within the same plane as the first optical window, and directing fluid through the second fluid nozzle comprises directing fluid within the same plane as the second optical window.

11. The method of claim 9, wherein the first fluid nozzle defines a first fluid axis extending through a center of the first fluid nozzle, the second fluid nozzle defines a second fluid axis extending through a center of the second fluid nozzle, and directing fluid through the first fluid nozzle comprises directing fluid so the first fluid axis intersects approximately a center of the first optical window, and directing fluid through the second fluid nozzle comprises directing fluid so the second fluid axis intersects approximately a center of the second optical window.

12. The method of claim 9, wherein the sensor head includes a sensor housing extending from a proximal end to a distal end, the sensor housing including an angular cutout defined by a first planar surface that intersects a second planar surface, wherein the first optical window is positioned in the first planar surface and the second optical window is positioned on the second planar surface.

13. The method of claim 12, wherein the first fluid nozzle and the second fluid nozzle project away from a wall of the flow chamber into the angular cutout.

14. The method of claim 13, further comprising directing light from the at least one light source through the first optical window into a first region of the angular cutout and receiving optical energy through the second optical window from a second region of the angular cutout, wherein the first fluid nozzle and the second fluid nozzle project into a third region of the angular cutout between the first region and the second region.

15. An optical sensor system comprising:

an optical sensor that comprises

a sensor head that includes an optical window, at least one light source configured to emit light through the optical window into a flow of fluid, and at least one detector configured to detect fluorescent emissions through the optical window from the flow of fluid; and

a flow chamber that includes a housing defining a cavity into which the sensor head is inserted, an inlet port configured to communicate the flow of fluid from outside of the cavity to an interior of the cavity, and an outlet port configured to communicate the flow of fluid from the interior of the cavity to back outside of the cavity, the inlet port defining a fluid nozzle configured to direct the flow of fluid against the optical window;

a liquid source configured to supply the flow of fluid communicating through the inlet port;

a gas source configured to supply the flow of fluid communicating through the inlet port; and

a controller configured to control the gas source to place the gas source in fluid communication with the flow chamber so as to evacuate the flow chamber of liquid, and control the liquid source so as to place the liquid source in fluid communication with the flow chamber so as to direct liquid through the fluid nozzle, through a space of the flow chamber evacuated of liquid, and against the optical window.

16. The optical sensor system of claim 15, wherein the optical window of the sensor head comprises a first optical window and a second optical window, the at least one light source being configured to emit light through the first optical window and the at least one detector being configured to detect fluorescent emissions through the second optical window, and the fluid nozzle of the flow chamber comprises a first fluid nozzle and a second fluid nozzle, the first fluid nozzle being configured to direct a portion of the flow of fluid against the first optical window and the second fluid nozzle being configured to direct a portion of the flow of fluid against the second optical window.

17. The optical sensor system of claim 16, wherein the first fluid nozzle defines a first fluid axis extending through a center of the first fluid nozzle, the second fluid nozzle defines a second fluid axis extending through a center of the second fluid nozzle, and the first fluid axis intersects approximately a center of the first optical window and the second fluid axis intersects approximately a center of the second optical window.

18. The optical sensor system of claim 16, wherein the sensor head includes a sensor housing extending from a proximal end to a distal end, the sensor housing including an angular cutout defined by a first planar surface that intersects a second planar surface, wherein the first optical window is positioned in the first planar surface and the second optical window is positioned on the second planar surface.

19. The optical sensor of claim 18, wherein the first planar surface intersects the second planar surface to define an approximately 90 degree angle, the first optical window and the second optical window are positioned within a same plane between the proximal end and the distal end of the sensor housing, and the first fluid nozzle and the second fluid nozzle are positioned within the same plane as the first optical window and the second optical window.

20. The optical sensor of claim 18, wherein the first fluid nozzle and the second fluid nozzle project away from a wall of the flow chamber into the angular cutout.

21. The optical sensor of claim 15, wherein the gas source is atmospheric air.

22. The optical sensor of claim 15, further comprising a first valve positioned between the gas source and the flow chamber and a second valve positioned between the liquid source and the flow chamber, wherein the controller is configured to control the liquid source so as to place the liquid source in fluid communication with the flow chamber by opening the second valve, and the controller is further configured to control the gas source to place the gas source in fluid communication with the flow chamber by opening the first valve.

23. A method comprising:

evacuating a flow chamber of an optical sensor of liquid, wherein the optical sensor includes a sensor head having an optical window that is inserted into the flow chamber, and the flow chamber includes an inlet port defining a fluid nozzle configured to direct fluid against the optical window;

flowing liquid through the inlet port of the flow chamber so as to direct liquid through the fluid nozzle, through a space of the flow chamber evacuated of liquid, and against the optical window.

24. The method of claim 23, wherein evacuating the flow chamber comprises controlling a gas source to place the gas source in fluid communication with the flow chamber, and flowing liquid through the inlet port comprises controlling a liquid source so as to place the liquid source in fluid communication with the flow chamber.

25. The method of claim 24, wherein the gas source is atmospheric air.

26. The method of claim 24, wherein controlling the gas source comprises controlling a first valve positioned between the gas source and the flow chamber, and controlling the liquid source comprises controlling a second valve positioned between the liquid source and the flow chamber.

27. The method of claim 23, wherein the optical window of the sensor head comprises a first optical window and a second optical window and the optical sensor further comprises at least one light source configured to emit light through the first optical window and at least one detector configured to detect fluorescent emissions through the second optical window, and wherein the fluid nozzle of the flow chamber comprises a first fluid nozzle and a second fluid nozzle, the first fluid nozzle being configured to direct fluid against the first optical window and the second fluid nozzle being configured to direct fluid against the second optical window.

28. The method of claim 27, wherein the first fluid nozzle defines a first fluid axis extending through a center of the first fluid nozzle, the second fluid nozzle defines a second fluid axis extending through a center of the second fluid nozzle, and the first fluid axis intersects approximately a center of the first optical window and the second fluid axis intersects approximately a center of the second optical window.

29. The method of claim 27, wherein the sensor head includes a sensor housing extending from a proximal end to a distal end, the sensor housing including an angular cutout defined by a first planar surface that intersects a second planar surface, wherein the first optical window is positioned in the first planar surface and the second optical window is positioned on the second planar surface.

30. The method of claim 29, wherein the first planar surface intersects the second planar surface to define an approximately 90 degree angle, the first optical window and the second optical window are positioned within a same plane between the proximal end and the distal end of the sensor housing, and the first fluid nozzle and the second fluid nozzle are positioned within the same plane as the first optical window and the second optical window.