US3739258A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detecting and sizing microscopic particles
Assignee: IIT Research Institute
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Filing: 1971-08-20
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Granted: 1973-06-12
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Expires: 1991-08-20
Abstract
Abstract Improved accuracy of size measurement and size distribution of particles in a fluid have been obtained in an electrical zone sensing apparatus by a flow control director means which directs the fluid in a more streamlined, less turbulent flow through an aperture at which the particles are electrically sensed. Also, the particles were directed and guided to flow substantially parallel to longitudinal axis for the aperture. The preferred flow control detector means comprises a contoured orifice having a smooth tapered inlet wall blended at an intersection with a central cylindrical wall defining a tubular shaped aperture.
Inventors
- 👤 R Karuhn
- 👤 R Davies
- 👤 J Clinch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:54
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/10; G01N15/1031; G01N15/12; G01N15/13
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
120 words
A method of sensing and determining the size of small particles suspended in liquid by passing the same through an aperture in a wafer, comprising the steps of: suspending the particles throughout the liquid which carries the particles through the aperture, inducing liquid flow through an aperture to carry the suspended particles through said aperture, directing the liquid upstream of said aperture into a substantially non-turbulent flow for passing into and through said aperture without substantial turbulence, directing the liquid and particles to flow along paths substantially parallel to a central axis for said aperture and in said substantially non-turbulent liquid flow through said aperture, and electrically sensing and measuring the size characteristics of the particles passing through sAid aperture.
Claim 2
Independent Claim
120 words
A method of sensing and determining the size of small particles suspended in liquid by passing the same through an aperture in a wafer, comprising the steps of: suspending the particles throughout the liquid which carries the particles through the aperture, inducing liquid flow through an aperture to carry the suspended particles through said aperture, directing the liquid upstream of said aperture into a substantially non-turbulent flow for passing into and through said aperture without substantial turbulence, directing the liquid and particles to flow along paths substantially parallel to a central axis for said aperture and in said substantially non-turbulent liquid flow through said aperture, and electrically sensing and measuring the size characteristics of the particles passing through sAid aperture.
Claim 3
Dependent Claim
37 words
A method in accordance with claim 1 in which directing the liquid into a non-turbulent flow comprises passing the liquid through a smooth, curved narrowing cross section transition zone prior to directing the liquid through said aperture.
Claim 4
Dependent Claim
213 words
In an apparatus for sensing and determining the size of small particles suspended in a liquid, the combination comprising: means for containing the liquid and suspended particles to be sensed and sized, receiving means for receiving the liquid and particles subsequent to the sensing and sizing thereof, a wafer including a wall defining an aperture interconnecting and in fluid communication with said containing means and said receiving means, means for inducing liquid flow through said aperture to carry the suspended particles through said aperture, a flow directing wall on said wafer upstream of said aperture having a converging wall smoothly blended with said wall defining said aperture for directing liquid and particles upstream of said aperture into a substantially non-turbulent flow through said aperture, said wafer having an outer upstream face wall and having a curved surface joining upstream face wall within said flowing directing wall without a sharp edge juncture to reduce turbulence in fluid flowing past said face wall to said flow directing wall, said flow directing wall directing the particles to flow along paths substantially parallel with the central axis of said aperture and in said substantially non-turbulent liquid flow through said aperture, and means for electrically sensing and measuring the size characteristics of the particles passing through said aperture.
Claim 5
Dependent Claim
213 words
In an apparatus for sensing and determining the size of small particles suspended in a liquid, the combination comprising: means for containing the liquid and suspended particles to be sensed and sized, receiving means for receiving the liquid and particles subsequent to the sensing and sizing thereof, a wafer including a wall defining an aperture interconnecting and in fluid communication with said containing means and said receiving means, means for inducing liquid flow through said aperture to carry the suspended particles through said aperture, a flow directing wall on said wafer upstream of said aperture having a converging wall smoothly blended with said wall defining said aperture for directing liquid and particles upstream of said aperture into a substantially non-turbulent flow through said aperture, said wafer having an outer upstream face wall and having a curved surface joining upstream face wall within said flowing directing wall without a sharp edge juncture to reduce turbulence in fluid flowing past said face wall to said flow directing wall, said flow directing wall directing the particles to flow along paths substantially parallel with the central axis of said aperture and in said substantially non-turbulent liquid flow through said aperture, and means for electrically sensing and measuring the size characteristics of the particles passing through said aperture.
Claim 6
Dependent Claim
22 words
An apparatus in accordance with claim 3 in which said curved wall is about 2 times the axial length of said aperture.
Claim 7
Dependent Claim
24 words
An apparatus in accordance with claim 3 in which said curved wall has a maximum diameter about 5 times the diameter of said aperture.
References Cited (Backward Citations)
US3628140A
Cited
US3638677A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |