US5369033A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Supercritical fluid contamination monitor
Assignee: Raytheon Co
•
Filing: 1992-01-24
•
Granted: 1994-11-29
•
Expires: 2012-01-24
Abstract
Abstract A system for monitoring changes in the amount of contaminants present in a flowing stream of supercritical fluid. A sample stream is removed from a flowing stream of supercritical fluid and subjected to reduced pressure. The supercritical fluid turns into gas at the reduced pressure with the contaminants remaining in a non-gaseous form. A quartz crystal microbalance system measures changes in the amount of non-gaseous contaminants present in the sample stream. The system is useful in monitoring both cleaning processes and extraction processes utilizing supercritical fluids.
Inventors
- 👤 Edward S. Di Milia
- 👤 Darrell A. Gleichauf
- 👤 Thomas E. Whiting
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:19
CPC Classifications
G; G01; G01N; G01N30/00; G01N5/00; G01N5/04; G01N1/00; G01N1/02; G01N1/10; G01N1/20; G01N1/2035
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
174 words
A system for monitoring contaminants present in a flowing stream of supercritical fluid wherein the amount of said contaminants decreases with time, said system comprising: a tube for containing said flowing stream of supercritical fluid; a contaminant measurement zone connected to said tube; sampling means for removing at least a portion of supercritical fluid from said flowing stream and introducing said portion of supercritical fluid into said contaminant measurement zone as a sample stream; pressure release means connected to said measurement zone for maintaining the pressure within said measurement zone at or below the level required to convert said sample stream into a gas wherein said contaminants present in said sample stream remain in a non-gaseous form in said measurement zone; a quartz crystal microbalance system in said measurement zone, on which said contaminants deposit in non-gaseous form for measuring changes in the amount of contaminants introduced into said measurement zone by said sample stream to thereby provide for monitoring of decreases in the amount of contaminants in said flowing stream of supercritical fluid.
Claim 2
Independent Claim
174 words
A system for monitoring contaminants present in a flowing stream of supercritical fluid wherein the amount of said contaminants decreases with time, said system comprising: a tube for containing said flowing stream of supercritical fluid; a contaminant measurement zone connected to said tube; sampling means for removing at least a portion of supercritical fluid from said flowing stream and introducing said portion of supercritical fluid into said contaminant measurement zone as a sample stream; pressure release means connected to said measurement zone for maintaining the pressure within said measurement zone at or below the level required to convert said sample stream into a gas wherein said contaminants present in said sample stream remain in a non-gaseous form in said measurement zone; a quartz crystal microbalance system in said measurement zone, on which said contaminants deposit in non-gaseous form for measuring changes in the amount of contaminants introduced into said measurement zone by said sample stream to thereby provide for monitoring of decreases in the amount of contaminants in said flowing stream of supercritical fluid.
Claim 3
Dependent Claim
60 words
A system for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 1 wherein said sampling means comprises a capillary sampling tube having an inlet connected to said tube containing said flowing stream of supercritical fluid and an outlet located within said contaminant measurement zone through which said sample stream is introduced into said measurement zone.
Claim 4
Dependent Claim
41 words
A system for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 2 wherein said sampling means includes a sampling valve operable between open and closed positions for controllably introducing said sample stream into said measurement zone.
Claim 5
Dependent Claim
55 words
A system for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 2 wherein said sampling means includes means located in said measuring zone adjacent to said outlet of said capillary tube for controllably removing contaminants from said sample stream as said sample streams exits said capillary tube through said outlet.
Claim 6
Dependent Claim
72 words
A system for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 4 wherein said means for controllably removing contaminants from said sample stream comprises a shutter located adjacent to said capillary tube outlet, said shutter being operable between an open position wherein contaminants are not captured by said shutter and a closed position wherein said contaminants are captured by said shutter and removed from said sample stream.
Claim 7
Dependent Claim
61 words
A system for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 1 wherein said measurement zone is located within a measurement vessel and wherein said pressure release means comprises a pressure relief opening in said vessel to allow escape of gas from said vessel to maintain the pressure in said measurement zone at an ambient level.
Claim 8
Dependent Claim
66 words
A system for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 1 wherein said quartz crystal microbalance system comprises a quartz crystal microbalance detector located within said measurement zone wherein said detector comprises a quartz crystal wafer which is exposed to said contaminants which deposit thereon, said system further including means for periodically cleaning said contaminants from said quartz crystal wafer.
Claim 9
Dependent Claim
52 words
A system for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 7 wherein said pressure release means further comprises a pressure valve connected to said pressure relief opening, said pressure valve being operable between a closed position to provide pressurization of said vessel and an open position.
Claim 10
Dependent Claim
74 words
A system for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 7 wherein said means for periodically cleaning deposited contaminants from said quartz crystal wafer comprises: a cleaning fluid inlet in said vessel; means for introducing cleaning fluid into contact with said quartz crystal wafer to produce used cleaning fluid containing contaminants removed from said quartz crystal wafer; and means for removing said used cleaning fluid from said vessel.
Claim 11
Dependent Claim
69 words
A system for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 7 wherein said quartz crystal microbalance system comprises a quartz crystal microbalance reference and means for establishing a beat frequency between said quartz crystal microbalance detector and said quartz crystal microbalance reference wherein changes in said beat frequency provide an indication of changes in the amount of contaminants introduced into said measurement zone.
Claim 12
Independent Claim
134 words
A method for monitoring contaminants present in a flowing stream of supercritical fluid comprising the steps of: removing at least a portion of supercritical fluid from said flowing stream and introducing said portion of supercritical fluid into a contaminant measurement zone as a sample stream; maintaining the pressure within said measurement zone at or below the level required to convert said sample stream into a gas wherein said contaminants present in said sample stream remain in a non-gaseous form; using a quartz crystal microbalance system in said measurement zone to measure changes in the amount of contaminants introduced into said measurement zone by said sample stream wherein contaminants deposit on said quartz crystal microbalance system to thereby provide for monitoring of changes in the amount of contaminants in said flowing stream of supercritical fluid.
Claim 13
Independent Claim
134 words
A method for monitoring contaminants present in a flowing stream of supercritical fluid comprising the steps of: removing at least a portion of supercritical fluid from said flowing stream and introducing said portion of supercritical fluid into a contaminant measurement zone as a sample stream; maintaining the pressure within said measurement zone at or below the level required to convert said sample stream into a gas wherein said contaminants present in said sample stream remain in a non-gaseous form; using a quartz crystal microbalance system in said measurement zone to measure changes in the amount of contaminants introduced into said measurement zone by said sample stream wherein contaminants deposit on said quartz crystal microbalance system to thereby provide for monitoring of changes in the amount of contaminants in said flowing stream of supercritical fluid.
Claim 14
Dependent Claim
32 words
A method for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 11 wherein said sample stream is introduced into said measurement zone through a capillary sampling tube.
Claim 15
Dependent Claim
42 words
A method for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 12 wherein said sample stream is removed from said flowing stream and introduced into said measurement zone only after a preselected amount of time has elapsed.
Claim 16
Dependent Claim
43 words
A method for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 13 wherein contaminants present in said sample stream are removed to prevent measurement by said quartz crystal microbalance system until a preselected amount of time has elapsed.
Claim 17
Dependent Claim
63 words
A method for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 14 wherein said contaminants are selectively removed from said sample stream by a shutter which is operable between an open position wherein contaminants are not captured by said shutter and a close position wherein said contaminants are captured by said shutter and removed from said sample stream.
Claim 18
Dependent Claim
30 words
A method for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 11 wherein said pressure in said measurement zone is maintained at approximately ambient pressure.
Claim 19
Dependent Claim
69 words
A method for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 11 wherein said quartz crystal microbalance system comprises a quartz crystal microbalance detector located within said measurement zone wherein said detector comprises a quartz crystal detector wafer which is exposed to said contaminants which deposit thereon, said method further including the step of periodically cleaning said contaminants from said quartz crystal detector wafer.
Claim 20
Dependent Claim
37 words
A method for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 17 wherein said step of periodically cleaning said quartz crystal detector wafer is accomplished by cleaning said wafer with supercritical fluid.
Claim 21
Dependent Claim
41 words
A method for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 17 wherein said step of periodically cleaning said quartz crystal detector wafer is accomplished by cleaning said wafer at ambient pressure with a cleaning fluid.
Claim 22
Dependent Claim
75 words
A method for monitoring contaminants present in a flowing stream of supercritical fluid according to claim 17 wherein said method includes the step of providing a quartz crystal microbalance reference which comprises a quartz crystal reference wafer and establishing a beat frequency between said quartz crystal detector wafer and said quartz crystal reference wafer, wherein changes in said beat frequency provide an indication of changes in the amount of contaminants introduced into said measurement zone.
References Cited (Backward Citations)
US3863495A
Cited
US4124528A
Cited
US4434028A
Cited
US4597943A
Cited
US4735081A
Cited
US4917499A
Cited
US4872316A
Cited
US5056355A
Cited
EP0444946A2
Cited
US5009746A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-11-28 | 1998-05-30 | 1998-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-28 | 2002-05-30 | 2002-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-28 | 2006-05-30 | 2006-11-29 | $7700.00 | Window Closed / Lapsed |