Condensation particle counters and methods of use

Patent metadata

Field	Value
Publication number	US-12130222-B2
Application number	US-202217839565-A
Country	US
Kind code	B2
Filing date	Jun 14, 2022
Priority date	Jun 15, 2021
Publication date	Oct 29, 2024
Grant date	Oct 29, 2024

Abstract

Disclosed is a method for detecting and/or growing particles, comprising controlling the surface area exposed to the saturator region by monitoring at least one of a depth of the working liquid on the saturator surface, the surface area exposed to the saturator region, or a volume of the working liquid on the saturator surface. Also disclosed is an apparatus or system for detecting and/or growing particles, comprising a fluidics system configured to control the surface area exposed to the saturator region by monitoring at least one of a depth of the working liquid on the saturator surface, the surface area exposed to the saturator region, or a volume of the working liquid on the saturator surface. Certain aspects do not employ one or more porous structures for vapor generation, nor a separate carrier fluid flow or inlet comprising a carrier fluid and vaporized working liquid for combining with the sample flow in the saturator region.

First claim

We claim:

1. A method for detecting or growing particles, comprising:
providing an apparatus comprising a working liquid and a saturator region, wherein the working liquid comprises a bulk working liquid having a working liquid surface exposed to and interacting with a sample flow, the working liquid surface characterized by a surface area, and the working liquid is positioned on a saturator surface in the saturator region,
evaporating at least a portion of the working liquid to form a working liquid vapor,
directing the sample flow comprising particles into the working liquid vapor positioned in the saturator region, resulting in a mixture comprising the sample flow and the working liquid vapor, wherein the mixture is in turbulent flow,
transporting the mixture through a condenser and cooling the mixture therein, wherein at least a portion of the working liquid vapor condenses on at least a portion of the particles of the sample flow and increases the size of the particles of the sample flow, thereby generating enlarged particles,
directing the enlarged particles to a particle counter, and
controlling the surface area exposed to the saturator region by monitoring at least one of a depth of the working liquid on the saturator surface, the surface area exposed to the saturator region, or a volume of the working liquid on the saturator surface.

2. The method of claim 1 , further comprising supplying additional working liquid to maintain;
a target range of the surface area, wherein the target range of the surface area is 0.01 to 500 cm 2 ;
a target range of the depth, wherein the target range of the depth is 0.001 to 100 mm; and/or
a target range of the volume, wherein the target range of the volume is 0.001 to 5000 mL.

3. A method for detecting or growing particles, comprising:
providing an apparatus comprising a working liquid and a saturator region, wherein the working liquid comprises a bulk working liquid having a working liquid surface exposed to the saturator region characterized by a surface area, and the working liquid is positioned on a saturator surface in the saturator region,
evaporating at least a portion of the working liquid to form a working liquid vapor,
directing a sample flow comprising particles into the working liquid vapor and toward the working liquid surface, resulting in a mixture of the sample flow and the working liquid vapor, wherein the mixture is in turbulent flow, and
transporting the mixture through a condenser and cooling the mixture therein, wherein at least a portion of the working liquid vapor condenses on at least a portion of the particles of the sample flow and increases the size of the particles of the sample flow, thereby generating enlarged particles, and
directing the enlarged particles to a particle counter.

4. The method of claim 1 , wherein the working liquid comprises a pool of working liquid or a stream of working liquid.

5. The method of claim 1 , wherein the directing step causes the sample flow to travel into the working liquid vapor and/or against the working liquid surface without causing formation of bubbles of the sample flow in the bulk working liquid beneath the working liquid surface.

6. The method of claim 1 , wherein the mixture consists of the sample flow and the working liquid vapor and wherein the working liquid vapor is in contact with the working liquid surface.

7. The method of claim 1 , wherein the evaporating step is substantially free of, or does not employ, one or more porous structures configured to facilitate generation of the working liquid vapor.

8. The method of claim 1 , wherein the working liquid has a dynamic viscosity of 0.0001 to 1.0 Ns/m 2 , a boiling point of 80° C. to 230° C., a specific gravity of 0.8 to 2.0 g/mL, or any combination thereof.

9. The method of claim 1 , wherein the sample flow has substantially laminar flow prior to the directing step and during the transporting step.

10. The method of claim 1 , wherein the condenser comprises an inner wall positioned along a vertical axis of the apparatus and defining a central passageway, and an outer wall positioned along the vertical axis and encircling the inner wall, wherein a circumferential passageway is formed between the inner wall and the outer wall,
at least a portion of the inner wall that is exposed to the circumferential passageway comprises a first material,
at least a portion of the outer wall that is exposed to the circumferential passageway comprises a second material, and
the first material has a lower thermal conductivity than the second material, and
the method further comprises cooling at least a portion of the outer wall that is exposed to the circumferential passageway and flowing the sample flow through the central passageway to the directing step,
wherein the transporting is performed in the circumferential passageway, and the flowing is parallel to, but in an opposite direction of, the transporting.

11. The method of claim 1 , further comprising detecting the enlarged particles using the particle counter; wherein the particle counter is an optical particle counter based on detection of scattering, extinction, interferometry, emission, or any combination thereof or a non-optical particle counter based on Coulter method, charging/measuring charge, zeta potential, or vision based particle counting systems.

12. An apparatus for detecting or growing particles, comprising:
a saturator region comprising a saturator surface, the saturator surface configured to support a working liquid that generates a working liquid vapor, wherein the working liquid, when present, comprises a bulk working liquid having a working liquid surface exposed to the saturator region, the working liquid surface characterized by a surface area,
a fluid inlet in fluid communication with the saturator region, the fluid inlet terminating at a nozzle configured to direct a sample flow comprising particles against and/or into the working liquid vapor to produce a mixture in turbulent flow, the mixture comprising the sample flow and the working liquid vapor,
a condenser in fluid communication with the saturator region, the condenser configured to receive and cool the mixture for condensing at least a portion of the working liquid vapor onto at least a portion of the particles, thereby forming enlarged particles,
a fluid outlet in fluid communication with the condenser configured to receive the enlarged particles, and
a fluidics system configured to control the surface area exposed to the saturator region by monitoring at least one of a depth of the working liquid on the saturator surface, the surface area exposed to the saturator region, or a volume of the working liquid on the saturator surface.

13. The apparatus of claim 12 , wherein the fluidics system is configured to supply additional working liquid to maintain:
a target range of the surface area, wherein the target range of the surface area is 0.01 to 500 cm 2 ;
a target range of the depth, wherein the depth is 0.001 to 100 mm; and/or
a target range of the volume, wherein the volume is 0.001 to 5000 mL.

14. The apparatus of claim 12 , further comprising:
a vertical axis,
wherein the condenser comprises an inner wall positioned along the vertical axis and defining a central passageway, and an outer wall positioned along the vertical axis and encircling the inner wall, wherein a circumferential passageway is formed between the inner wall and the outer wall,
wherein the central passageway is in fluid communication with and positioned between the fluid inlet and the nozzle, the circumferential passageway is in fluid communication with an

Assignees

• Particle Measuring Syst

Inventors

• Yates Edward
• Hertert Cary
• Knollenberg Brian A

Classifications

• G01N2015/1024

  Counting particles by non-optical means · CPC title

• G01N15/14

  Optical investigation techniques, e.g. flow cytometry · CPC title

• G01N2015/1486

  Counting the particles · CPC title

• G01N15/10 Primary

  Investigating individual particles · CPC title

• G01N15/065 Primary

  using condensation nuclei counters · CPC title