Patent US4784677A successfully refreshed from Google Patents.
US4784677A
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Process and apparatus for controlling argon column feedstreams
Assignee: Messer LLC
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Filing: 1987-07-16
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Granted: 1988-11-15
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Expires: 2007-07-16
Abstract
Abstract The present invention relates to methods and apparatus for controlling a process for the separation of air to obtain oxygen, argon, and nitrogen products, and more particularly for controlling the composition of the feedstream to a column for producing crude argon. The nitrogen content of the feedstream is directly analyzed in real time and maintained within a preselected range. The results of the analysis is used to control the operation of the process, for example, by adjusting the reflux or product withdrawal rates. Argon production is thereby maximized without risking a dumping phenomenon in the crude argon column.
Inventors
- 👤 Ismael Al-Chalabi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:26
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/04; F25J3/04763; F25J3/04769; F25J3/04793; F25J3/048; F25J3/04406; F25J3/04412; F25J3/04642; F25J3/04648; F25J3/04654; F25J3/04666; F25J3/04672; F25J3/04678; F25J3/04848; F25J2290/00; F25J2290/10; Y; Y10; Y10S; Y10S62/00; Y10S62/923; Y10S62/924
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
114 words
A process for separation of air by low temperature rectification capable of producing an oxygen, argon and nitrogen product which comprises: subjecting air to a two-stage rectification wherein a nitrogen rich reflux liquid from a first rectification stage is introduced into a secomd rectification stage to wash the rising vapor at the top poriton of said second rectification stage and withdrawing from a zone of the second rectification stage where the argon content is high, a feedstream which is passed to a crude argon rectification stage, the improvement comprising analyzing in real time the nitrogen content of said feedstream and controlling the operation of said process in response to the results of said analysis.
Claim 2
Dependent Claim
114 words
A process for separation of air by low temperature rectification capable of producing an oxygen, argon and nitrogen product which comprises: subjecting air to a two-stage rectification wherein a nitrogen rich reflux liquid from a first rectification stage is introduced into a secomd rectification stage to wash the rising vapor at the top poriton of said second rectification stage and withdrawing from a zone of the second rectification stage where the argon content is high, a feedstream which is passed to a crude argon rectification stage, the improvement comprising analyzing in real time the nitrogen content of said feedstream and controlling the operation of said process in response to the results of said analysis.
Claim 3
Dependent Claim
21 words
The process of claim 1, wherein in response to the nitrogen content analysis, one or more product withdrawal rates are adjusted.
Claim 4
Dependent Claim
20 words
The process of claim 2, wherein in response to the nitrogen content analysis, the oxygen product withdrawal rate is adjusted.
Claim 5
Dependent Claim
18 words
The process of claim 2, wherein in response to the nitrogen content analysis, the argon production is adjusted.
Claim 6
Dependent Claim
24 words
The process of claim 1, wherein in response to the nitrogen content analysis, the reflux flow rate to the second stage rectification is adjusted.
Claim 7
Dependent Claim
25 words
The process of claim 1, additionally including the step of measuring the oxygen content of a waste nitrogen stream produced in said second rectification stage.
Claim 8
Dependent Claim
68 words
The process of claim 6, wherein a first controller means is associated with an analyzer means for determining said nitrogen content and a second controller means is associated with an analyzer means for determining the oxygen content of a waste nitrogen stream exiting said second rectification stage and wherein the controllers are cascaded, the first controller being the master controller and the second controller being the slave controller.
Claim 9
Dependent Claim
27 words
The process of claim 7, wherein the second controller maintains a predetermined operating line in the low pressure column, said line being determined by the first controller.
Claim 10
Dependent Claim
28 words
The process of claim 7, wherein said nitrogen content, the rate of change thereof and an integrated history of the nitrogen content are inputed into said first controller.
Claim 11
Dependent Claim
24 words
The process of claim 7, wherein the output of said first controller is used as a set point with respect to said second controller.
Claim 12
Dependent Claim
28 words
The process of claim 1, wherein said analysis is utilized to maintain the nitrogen content in the feedstream to the crude argon rectification stage within a preselected range.
Claim 13
Dependent Claim
14 words
The process of claim 11, wherein said preselected range is below about 10,000 ppm.
Claim 14
Dependent Claim
15 words
The process of claim 12, wherein said preselected range is between 10 and 7000 ppm.
Claim 15
Dependent Claim
16 words
The process of claim 13, wherein said preselected range is between about 100 to 2000 ppm.
Claim 16
Dependent Claim
31 words
The process of claim 1, wherein the nitrogen content is determined by a real time analyzer means selected from the group consisting of visible emission spectroscopy, laser spectroscopy and absorption spectroscopy.
Claim 17
Dependent Claim
15 words
The process of claim 15, wherein the nitrogen content is determined by visible emission spectroscopy.
Claim 18
Dependent Claim
17 words
The process of claim 15, wherein the response time of the analyzer is under about 5 minutes.
Claim 19
Dependent Claim
14 words
The process of claim 7, wherein the response time is under about 1 minute.
Claim 20
Dependent Claim
14 words
The process of claim 18, wherein the response time is 0.01 to 15 seconds.
Claim 21
Dependent Claim
19 words
The process of claim 1, additionally including the step of determining the argon and oxygen content of the feedstream.
Claim 22
Dependent Claim
18 words
The process of claim 1, wherein the second rectification stage is controlled by adjusting the reflux ratio thereto.
Claim 23
Dependent Claim
14 words
The process of claim 1, wherein an oxygen and a nitrogen product are formed.
Claim 24
Dependent Claim
15 words
The method of claim 1, wherein said feedstream is comprised mainly of oxygen and argon.
Claim 25
Dependent Claim
19 words
The process of claim 1, wherein in response to the nitrogen content analysis, the feedstream flow rate is adjusted.
Claim 26
Independent Claim
181 words
A system for controlling the separation of air by low temperature rectification to obtain argon and at least one of oxygen and nitrogen wherein air is subjected to a two-stage rectification in which a nitrogen rich reflux fluid is passed from a first rectification column to a second rectification column for washing the rising vapor of the said second rectification column and wherien a sidestream is withdrawn from said second rectification column and introduced for further rectification into a third column for the production of crude argon comprising: (i) a first analyzer means for on-line sensing in real time of the nitrogen content of said sidestream passing from said second rectification column to said third column; and (ii) a second analyzer means for sensing the oxygen content of a waste nitrogen stream of said second rectification column; and (iii) a means for controlling the operating line of the second rectification column, based on the inputs of said first and second analyzer means, by controlling the reflux flow of nitrogen rich fluid from said first rectification column to said second rectification column.
Claim 27
Independent Claim
181 words
A system for controlling the separation of air by low temperature rectification to obtain argon and at least one of oxygen and nitrogen wherein air is subjected to a two-stage rectification in which a nitrogen rich reflux fluid is passed from a first rectification column to a second rectification column for washing the rising vapor of the said second rectification column and wherien a sidestream is withdrawn from said second rectification column and introduced for further rectification into a third column for the production of crude argon comprising: (i) a first analyzer means for on-line sensing in real time of the nitrogen content of said sidestream passing from said second rectification column to said third column; and (ii) a second analyzer means for sensing the oxygen content of a waste nitrogen stream of said second rectification column; and (iii) a means for controlling the operating line of the second rectification column, based on the inputs of said first and second analyzer means, by controlling the reflux flow of nitrogen rich fluid from said first rectification column to said second rectification column.
Claim 28
Dependent Claim
18 words
The system of claim 25, wherein the response time of the analyzer means is under about 5 minutes.
Claim 29
Dependent Claim
14 words
The system of claim 25, wherein the response time is under about 1 minute.
Claim 30
Dependent Claim
14 words
The system of claim 25, wherein the response time is 0.01 to 15 seconds.
Claim 31
Dependent Claim
49 words
The system of claim 25, wherein said controller means comprises a first controller means associated with said first analyzer means and a second controller means associated with said second analyzer means, said controller means being cascaded, the first controller means being primary and the second controller means being secondary.
Claim 32
Dependent Claim
32 words
The system of claim 29, wherein said second controller means is adapted to maintain a predetermined operating line in the low pressure column, said line being determined by the first controller means.
Claim 33
Dependent Claim
30 words
The system of claim 25, further comprising a means for adjusting an additional operating parameter of said air separation process based on the inputs of said first and second analyzer.
Claim 34
Dependent Claim
15 words
The system of claim 31, further comprising a means for adjusting a product withdrawal rate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-15 | 1992-05-16 | 1992-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-15 | 1996-05-16 | 1996-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-15 | 2000-05-16 | 2000-11-15 | $7700.00 | Window Closed / Lapsed |