US4672218A
Expired / Lapsed
US
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Method for determining the onset of crystallization
Assignee: Dow Chemical Co
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Filing: 1984-12-04
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Granted: 1987-06-09
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Expires: 2004-12-04
Abstract
Abstract A method for determining the onset of nucleation wherein a zone of a translucent fluid in which crystals may be formed is illuminated by a beam of light. When crystallization commences the crystals in the illuminated zone reflect and scatter light. Some of the scattered light is collected and transmitted to a light sensitive detector operable to generate a signal indicative of nucleation. Upon detection of nucleation either manual or automatic procedures may be instituted to modify the crystallization process in an appropriate manner.
Inventors
- 👤 Ray W. Chrisman
- 👤 Richard D. McLachlan
- 👤 Richard S. Harner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:56
CPC Classifications
G; G01; G01N; G01N25/00; G01N25/14; G01N25/147; B; B01; B01D; B01D9/00; B01D9/0063; G01N21/00; G01N21/17; G01N21/47; G01N21/49; G01N21/51; G01N21/84; G01N21/85; G01N21/8507
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
126 words
In a chemical process, a method of determining the presence in a translucent, continuous first phase fluid medium contained in a vessel of a discontinuous second phase having a refractive index different from that of said first phase, said method comprising: (a) inserting a probe in said vessel at such level as to be immersed in said fluid medium; (b) illuminating via said probe a zone of said fluid medium prior to the time that said second phase is present in said illuminated zone so that the presence of said second phase in said illuminated zone may scatter light; (c) collecting via said probe light scattered by said second phase present in said illuminated zone; and (d) transmitting said collected light to a light sensitive detector.
Claim 2
Dependent Claim
126 words
In a chemical process, a method of determining the presence in a translucent, continuous first phase fluid medium contained in a vessel of a discontinuous second phase having a refractive index different from that of said first phase, said method comprising: (a) inserting a probe in said vessel at such level as to be immersed in said fluid medium; (b) illuminating via said probe a zone of said fluid medium prior to the time that said second phase is present in said illuminated zone so that the presence of said second phase in said illuminated zone may scatter light; (c) collecting via said probe light scattered by said second phase present in said illuminated zone; and (d) transmitting said collected light to a light sensitive detector.
Claim 3
Dependent Claim
19 words
The method of claim 1 including treating said fluid medium in response to the detection of said scattered light.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein said second phase comprises crystals and said first phase comprises a liquid.
Claim 5
Dependent Claim
30 words
The method of claim 1 wherein said second phase comprises droplets of a first liquid and said first phase comprises a second liquid, said first and second liquids being immiscible.
Claim 6
Dependent Claim
21 words
The method of claim 1 wherein said second phase comprises droplets of a liquid and said first phase comprises a gas.
Claim 7
Dependent Claim
20 words
The method of claim 1 wherein said second phase comprises a non-crystalline solid and said first phase comprises a liquid.
Claim 8
Dependent Claim
19 words
The method of claim 1 wherein said second phase comprises gas bubbles and said first phase comprises a liquid.
Claim 9
Dependent Claim
19 words
The method of claim 1 wherein said second phase comprises solid particles and said first phase comprises a gas.
Claim 10
Dependent Claim
31 words
The method of claim 1 wherein said zone of said first phase is illuminated by light transmitted from a source thereof to said fluid medium via at least one optical fiber.
Claim 11
Dependent Claim
18 words
The method of claim 1 wherein said zone is illuminated by light emanating from a light emitting diode.
Claim 12
Dependent Claim
17 words
The method of claim 1 wherein said zone is illuminated by light emanating from a laser diode.
Claim 13
Dependent Claim
18 words
The method of claim 1 wherein said zone is illuminated by light emanating from a continuous wave laser.
Claim 14
Dependent Claim
13 words
The method of claim 1 wherein said light emanates from an incandescent lamp.
Claim 15
Dependent Claim
11 words
The method of claim 1 wherein said detector comprises a photodiode.
Claim 16
Dependent Claim
11 words
The method of claim 1 wherein said detector comprises a photomultiplier.
Claim 17
Dependent Claim
17 words
The method of claim 1 including filtering the scattered light prior to transmitting it to said detector.
Claim 18
Dependent Claim
108 words
In a crystallization process, a method of determining the formation in a translucent fluid medium contained in a vessel of light scattering crystals having a refractive index different from that of said medium, said method comprising: (a) inserting a probe in said vessel at such level as to be immersed in said fluid medium; (b) illuminating via said probe a zone of said fluid medium prior to the formation of crystals therein so that the presence of crystals in said illuminated zone may scatter light; (c) collecting via said probe light scattered by crystals present in said zone; and (d) transmitting the collected light to light detecting means.
Claim 19
Dependent Claim
108 words
In a crystallization process, a method of determining the formation in a translucent fluid medium contained in a vessel of light scattering crystals having a refractive index different from that of said medium, said method comprising: (a) inserting a probe in said vessel at such level as to be immersed in said fluid medium; (b) illuminating via said probe a zone of said fluid medium prior to the formation of crystals therein so that the presence of crystals in said illuminated zone may scatter light; (c) collecting via said probe light scattered by crystals present in said zone; and (d) transmitting the collected light to light detecting means.
Claim 20
Dependent Claim
21 words
The method of claim 17 including treating said liquid medium in a manner to cause crystals therein to traverse said zone.
Claim 21
Dependent Claim
10 words
The method of claim 18 including stirring said liquid medium.
Claim 22
Dependent Claim
10 words
The method of claim 18 including agitating said liquid medium.
Claim 23
Dependent Claim
12 words
The method of claim 18 including setting said liquid medium in motion.
Claim 24
Dependent Claim
35 words
The method of claim 17 including illuminating said zone by transmitting light to said probe via at least one optical fiber and transmitting scattered light from said probe via at least one other optical fiber.
Claim 25
Dependent Claim
19 words
The method of claim 17 including modifying said fluid medium in response to the detection of said scattered light.
References Cited (Backward Citations)
US3695763A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1990-06-08 | 1990-12-08 | 1991-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-08 | 1994-12-08 | 1995-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-08 | 1998-12-08 | 1999-06-09 | $7700.00 | Window Closed / Lapsed |