US4539019A — Control system for air fractionation by selective…

Claim 1

Independent Claim 124 words

In the operation of a cyclic system for recovery of an enriched-oxygen effluent product by selective adsorption of nitrogen from an ambient air feed stream, wherein said ambient air previously freed of contained water and CO 2 is passed through a bed of solid adsorbent selective in retention of nitrogen as opposed to oxygen, with resulting production of an oxygen-enriched gaseous effluent which is withdrawn from said bed and collected in a receiver; and wherein the resulting nitrogen-loaded adsorbent is desorbed by application of vacuum thereto, followed by repressuring of the adsorbent bed with a portion of said oxygen-enriched gaseous effluent; the improvement which comprises automatically controlling the duration of the air feed step by monitoring the inventory of oxygen-enriched gas in said receiver.

Claim 2

Dependent Claim 124 words

In the operation of a cyclic system for recovery of an enriched-oxygen effluent product by selective adsorption of nitrogen from an ambient air feed stream, wherein said ambient air previously freed of contained water and CO 2 is passed through a bed of solid adsorbent selective in retention of nitrogen as opposed to oxygen, with resulting production of an oxygen-enriched gaseous effluent which is withdrawn from said bed and collected in a receiver; and wherein the resulting nitrogen-loaded adsorbent is desorbed by application of vacuum thereto, followed by repressuring of the adsorbent bed with a portion of said oxygen-enriched gaseous effluent; the improvement which comprises automatically controlling the duration of the air feed step by monitoring the inventory of oxygen-enriched gas in said receiver.

Claim 3

Dependent Claim 47 words

The improvement as defined in claim 1 in which said receiver is expansible and wherein said feeding of air is continued until said expansible receiver has been filled to a sensed preset height level, at which time further feeding of air to said bed is automatically discontinued.

Claim 4

Dependent Claim 45 words

The improvement as defined in claim 1 wherein said feeding of air is continued until a preset gas pressure level is detected in said receiver, at which time further feeding of air to said bed is automatically discontinued and vacuum desorption of said bed initiated.

Claim 5

Dependent Claim 45 words

The improvement as defined in claim 1 as applied to a cyclic system wherein the ambient air is freed of contained water and CO 2 by being passed through an adsorbent bed in series with said bed of solid adsorbent selective in retention of nitrogen.

Claim 6

Dependent Claim 129 words

In the fractionation of air by a vacuum swing adsorption process comprising the sequential steps of (1) introducing the air, freed of water and CO 2 , into a bed of adsorbent selective in retention of nitrogen and collecting the unadsorbed oxygen-enriched effluent in a first receiver; thereafter (2) rinsing the nitrogen-laden bed with a stream of high purity nitrogen gas withdrawn from storage in a second receiver; (3) desorbing the nitrogen-laden bed by application of vacuum thereto and passing the desorbed nitrogen effluent into said second receiver; and (4) repressuring said adsorbent bed by admission of oxygen-enriched gas therein withdrawn from said first receiver; the improvement which comprises controlling the duration of steps (1) and/or (2) respectively by monitoring the gas inventory in said first and/or second receivers.

Claim 7

Dependent Claim 129 words

In the fractionation of air by a vacuum swing adsorption process comprising the sequential steps of (1) introducing the air, freed of water and CO 2 , into a bed of adsorbent selective in retention of nitrogen and collecting the unadsorbed oxygen-enriched effluent in a first receiver; thereafter (2) rinsing the nitrogen-laden bed with a stream of high purity nitrogen gas withdrawn from storage in a second receiver; (3) desorbing the nitrogen-laden bed by application of vacuum thereto and passing the desorbed nitrogen effluent into said second receiver; and (4) repressuring said adsorbent bed by admission of oxygen-enriched gas therein withdrawn from said first receiver; the improvement which comprises controlling the duration of steps (1) and/or (2) respectively by monitoring the gas inventory in said first and/or second receivers.

Claim 8

Dependent Claim 38 words

The improvement as defined in claim 5 in which said first receiver is expansible and wherein the duration of step (1) is automatically terminated following actuation of a height level sensing means associated with said first expansible receiver.

Claim 9

Dependent Claim 42 words

The improvement as defined in claim 6 wherein following actuation of said height level sensing means the introduction of air and collection of the oxygen-enriched effluent is continued for a preset fixed time period after initial actuation of said level sensing means.

Claim 10

Dependent Claim 27 words

The improvement as defined in claim 5 wherein the duration of step (1) is automatically terminated after a preset pressure level is attained is said first receiver.

Claim 11

Dependent Claim 43 words

The improvement as defined in claim 8 wherein after said preset pressure level is attained in said first receiver the introduction of air and collection of the oxygen-enriched effluent is permitted to continue for a fixed time period before termination of step (1).

Claim 12

Dependent Claim 38 words

The improvement as defined in claim 5 in which said second receiver is expansible and wherein the duration of step (2) is automatically terminated following actuation of a height level sensing means associated with said second expansible receiver.

Claim 13

Dependent Claim 34 words

The improvement as defined in claim 10 wherein following actuation of said height level sensing means step (2) is continued for a preset fixed time period after initial actuation of said level sensing means.

Claim 14

Dependent Claim 27 words

The improvement as defined in claim 5 wherein the duration of step (2) is automatically terminated after a preset pressure level is attained in said second receiver.

Claim 15

Dependent Claim 39 words

The improvement as defined in claim 12 wherein after said preset pressure level is attained in said second receiver the operation of step (2) is permitted to continue for a fixed time period before the termination of step (2).

Claim 16

Dependent Claim 26 words

The improvement as defined in claim 5 wherein the vacuum desorption step (3) is continued until a preset vacuum level is attained in said adsorbent bed.

Claim 17

Dependent Claim 120 words

In a cyclic system for fractionation of air wherein during an on-stream period nitrogen is selectively adsorbed from the feed air in an adsorption column while collecting and storing in a surge vessel the oxygen-enriched primary gas effluent discharged from said adsorption column, and wherein the column laden with adsorbed nitrogen is subsequently desorbed under vacuum; means for controlling the duration of said on-stream air feed period comprising inventory monitoring means associated with said effluent storing surge vessel, said monitoring means being actuated when the sensed pressure level or the sensed height level of collected gas in said surge vessel attains a preset value, said monitoring means being operatively arranged to initiate valve closure terminating said on-stream air feed period.

Claim 18

Dependent Claim 120 words

In a cyclic system for fractionation of air wherein during an on-stream period nitrogen is selectively adsorbed from the feed air in an adsorption column while collecting and storing in a surge vessel the oxygen-enriched primary gas effluent discharged from said adsorption column, and wherein the column laden with adsorbed nitrogen is subsequently desorbed under vacuum; means for controlling the duration of said on-stream air feed period comprising inventory monitoring means associated with said effluent storing surge vessel, said monitoring means being actuated when the sensed pressure level or the sensed height level of collected gas in said surge vessel attains a preset value, said monitoring means being operatively arranged to initiate valve closure terminating said on-stream air feed period.

Claim 19

Dependent Claim 121 words

A cyclic system as defined in claim 15 further comprising a second surge vessel for storing the nitrogen gas desorbed from said nitrogen-laden column, means for withdrawing a portion of the stored nitrogen from said second surge vessel and flowing the same through said nitrogen-laden column to rinse said column after the termination of said onstream air feed period, and means to control the duration of said nitrogen rinse; said last-named means comprising inventory monitoring means associated with said second surge vessel, said monitoring means being actuated when the pressure level or the height level of nitrogen gas in said second surge vessel attains a preset value; said monitoring means being operatively arranged to initiate valve closure terminating said nitrogen rinsing.

Claim 20

Dependent Claim 55 words

A cyclic system as defined in claim 16 wherein said inventory monitoring means associated with said second surge vessel further includes a time-delay device for extending the duration of said nitrogen rinse period for a preset time period after actuation of said monitoring means, during which extended time period the defined valve closure is delayed.

Claim 21

Dependent Claim 57 words

A cyclic system as defined in claim 16 wherein said inventory monitoring means associated with said effluent-storing purge vessel further includes a time delay device for extending the duration of said on-stream air feed period for a preset time period following actuating of said monitoring means, during which extended time period the defined valve closure is delayed.

Claim 22

Dependent Claim 55 words

A cyclic system as defined in claim 15 wherein said inventory monitoring means associated with said effluent-storing surge vessel further includes a time delay device for extending the duration of said on-stream air feed period for a preset time period following actuation of said monitoring means, during which extended time period valve closure is delayed.

Claim 23

Dependent Claim 37 words

A cyclic system as defined in claim 15 further comprising means for controlling the duration of the recited vacuum desorption step, said control means comprising a vacuum level sensing switch operatively associated with the nitrogen adsorption column.

Claim 24

Dependent Claim 178 words

In a vacuum swing adsorption system for the fractionation of air wherein air free of water and carbon dioxide is introduced into a column of adsorbent selective in retention of nitrogen and the unadsorbed oxygen-enriched effluent is collected in a first surge vessel, the nitrogen-laden column is rinsed with a stream of high purity nitrogen gas withdrawn from a second surge vessel, the nitrogen-laden column is desorbed by application of vacuum thereto with the desorbed nitrogen effluent passing to said second surge vessel and repressurizing said column by admission of oxygen-enriched gas withdrawn from said first surge vessel; the improvement comprising means for controlling the duration of said air introduction and/or said rinsing of said nitrogen laden bed including an inventory monitoring means associated with said first and/or second surge vessels, said monitoring means being actuated when the sensed pressure level or the sensed height level of collected gas in the respective surge vessels attains a preset value, said monitoring means being operatively arranged to initiate valve closure terminating said air introduction period and/or said nitrogen rinse period.

Claim 25

Dependent Claim 178 words

In a vacuum swing adsorption system for the fractionation of air wherein air free of water and carbon dioxide is introduced into a column of adsorbent selective in retention of nitrogen and the unadsorbed oxygen-enriched effluent is collected in a first surge vessel, the nitrogen-laden column is rinsed with a stream of high purity nitrogen gas withdrawn from a second surge vessel, the nitrogen-laden column is desorbed by application of vacuum thereto with the desorbed nitrogen effluent passing to said second surge vessel and repressurizing said column by admission of oxygen-enriched gas withdrawn from said first surge vessel; the improvement comprising means for controlling the duration of said air introduction and/or said rinsing of said nitrogen laden bed including an inventory monitoring means associated with said first and/or second surge vessels, said monitoring means being actuated when the sensed pressure level or the sensed height level of collected gas in the respective surge vessels attains a preset value, said monitoring means being operatively arranged to initiate valve closure terminating said air introduction period and/or said nitrogen rinse period.

Claim 26

Dependent Claim 14 words

A system as defined in claim 21 wherein said first surge vessel is expansible.

Claim 27

Dependent Claim 14 words

A system as defined in claim 21 wherein said second surge vessel is expansible.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1988-09-02	1989-03-04	1989-09-03	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1992-09-02	1993-03-04	1993-09-03	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1996-09-02	1997-03-04	1997-09-03	$7700.00	Window Closed / Lapsed

Control system for air fractionation by selective adsorption

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag