Patent US4284498A successfully refreshed from Google Patents.
US4284498A
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Apparatus for field flow fractionation
Assignee: EIDP Inc
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Filing: 1980-02-29
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Granted: 1981-08-18
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Expires: 2000-02-29
Abstract
Abstract A long, thin annular belt-like channel is designed for use in sedimentation field flow fractionation. This channel, which may be contained in the rotor of a centrifuge, has a generally rectangular cross-section. It has an inlet positioned to introduce particulates (includes particles and/or macromolecules) approximately at the radial distance from the outer wall that is the equilibrium distance resulting from the average force field exerted on each particulate by the centrifugal force field and by the opposing normal diffusion forces due to Brownian motion. An outlet for the channel is similarly located. A modified design tapers the inlet and outlet.
Inventors
- 👤 John W. Grant
- 👤 Joseph J. Kirkland
- 👤 Wallace W. Yau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:38
CPC Classifications
B; B04; B04B; B04B5/00; B04B5/04; B03; B03B; B03B5/00; B04B5/0442; B04B2005/045; G; G01; G01N; G01N30/00; G01N30/0005; G01N2030/0015; G01N2030/002
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
135 words
An apparatus for separating particulates suspended in a fluid medium according to their effective masses, said apparatus having an annular cylindrical channel with a cylinder axis, means for rotating said channel about said axis, means for passing said fluid medium circumferentially through said channel, and means for introducing a sample of said particulates into said medium for passage through said channel, the improvement wherein said channel is generally rectangular in cross section, having radially inner and outer walls and inlet and outlet ends, and has an inlet positioned to introduce said particulates approximately at the radial distance 1 inwardly from the outer wall, where 1 is the point of equilibrium between the average force field exerted on each particulate by the rotational centrifugal force and by the normal opposing diffusion forces due to Brownian motion.
Claim 2
Independent Claim
135 words
An apparatus for separating particulates suspended in a fluid medium according to their effective masses, said apparatus having an annular cylindrical channel with a cylinder axis, means for rotating said channel about said axis, means for passing said fluid medium circumferentially through said channel, and means for introducing a sample of said particulates into said medium for passage through said channel, the improvement wherein said channel is generally rectangular in cross section, having radially inner and outer walls and inlet and outlet ends, and has an inlet positioned to introduce said particulates approximately at the radial distance 1 inwardly from the outer wall, where 1 is the point of equilibrium between the average force field exerted on each particulate by the rotational centrifugal force and by the normal opposing diffusion forces due to Brownian motion.
Claim 3
Dependent Claim
19 words
An apparatus of claim 1 wherein said channel also has an outlet positioned approximately at said radial distance 1.
Claim 4
Dependent Claim
27 words
An apparatus of claim 1 or 2 wherein said inlet is in the form of a radially oriented tube directed through the inner wall of said channel.
Claim 5
Dependent Claim
25 words
An apparatus of claim 2 wherein said outlet is in the form of a radially oriented tube directed through the inner wall of said channel.
Claim 6
Dependent Claim
48 words
An apparatus of claim 1 or 2 wherein said inlet is in the form of a radially oriented tube directed through the inner wall of said channel or wherein said outlet is in the form of a radially oriented tube directed through the inner wall of said channel.
Claim 7
Dependent Claim
35 words
An apparatus of claim 1 wherein said inlet is defined by the inner wall of said channel being tapered toward said outer wall whereby the radial thickness of said channel is reduced at said inlet.
Claim 8
Dependent Claim
17 words
An apparatus of claim 6 wherein said radial thickness is reduced by a factor of about 10.
Claim 9
Dependent Claim
35 words
An apparatus of claim 6 wherein said outlet is defined by the inner wall of said channel being tapered toward said outer wall whereby the radial thickness of said channel is reduced at said outlet.
Claim 10
Dependent Claim
35 words
An apparatus of claim 1 wherein said outlet is defined by the inner wall of said channel being tapered toward said outer wall whereby the radial thickness of said channel is reduced at said outlet.
Claim 11
Dependent Claim
17 words
An apparatus of claim 9 wherein said radial thickness is reduced by a factor of about 10.
Claim 12
Dependent Claim
24 words
An apparatus of claim 1 wherein 1 is in the range of 0.1 to 0.5 W, where W is the thickness of said channel.
References Cited (Backward Citations)
US4010894A
Cited
DE2821056A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-17 | 1985-02-16 | 1985-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-17 | 1989-02-16 | 1989-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-17 | 1993-02-16 | 1993-08-18 | $7700.00 | Window Closed / Lapsed |