EP0088905A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Adsorbent fractionator with automatic temperature-sensing cycle control and process
Assignee: Pall Corp
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Filing: 1983-02-18
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Granted: —
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Expires: 2003-02-18
Abstract
Abstract A method and apparatus are provided for adsorbing water vapor or other first gas from a mixture thereof with a second gas to reduce the water vapor or first gas concentration in the mixture to below a permissible maximum concentration, in which the advance of the leading edge of the adsorption front in a sorbent bed is detected by sensing the advance of the temperature front that precedes the adsorption front, and this advance is detected by sensing the temperature of the sorbent bed sufficiently far from the end of the bed to prevent the temperature front from leaving the bed, using a temperature sampling probe; when the temperature front reaches this point, the adsorption front is still a distance away, since it follows the temperature front, and the adsorption cycle is discontinued, and the bed regenerated; the regeneration cycle can similarly be controlled independently, to be terminated when regeneration is complete, as detected by advance of the temperature front in the opposite direction.
Inventors
- 👤 Donald H. White, Jr.
- 👤 Conrad Christel, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 18:00
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/02; B01D53/04; B01D53/0454; B01D53/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
262 words
A process for reducing the concentration of a first gas, for example, water vapor, in a mixture thereof with a second gas to below a limiting maximum concentration thereof in the second gas, which comprises passing the mixture in contact with and from one end to another end of bed of a sorbent having a preferential affinity for the first gas; such as water vapor; adsorbing first gas thereon to form a gaseous effluent having a concentration thereof below the maximum, and forming a concentration gradient of first gas in the bed progressively decreasing from one end to the other end as the adsorption continues, and an increasing concentration of first gas in the second gas defining a concentration front progressively advancing in the bed from the one end to the other end as sorbent capacity therefor decreases; and forming a temperature front in the sorbent bed in which the temperature of the bed is changing, progressively increasing while adsorption of first gas in the bed continues, and then leveling off and progressively decreasing when adsorption of first gas in the bed ceases; detecting the advance of the temperature front in the bed; and then, when the change in the temperature of the bed has reached a predetermined value corresponding to a selected degree of saturation of the bed with respect to first gas, discontinuing passing the gaseous mixture in contact with the bed before either the temperature front or the concentration front can leave the bed, and the limiting maximum concentration of first gas in the second gas can be exceeded.
Claim 2
Dependent Claim
262 words
A process for reducing the concentration of a first gas, for example, water vapor, in a mixture thereof with a second gas to below a limiting maximum concentration thereof in the second gas, which comprises passing the mixture in contact with and from one end to another end of bed of a sorbent having a preferential affinity for the first gas; such as water vapor; adsorbing first gas thereon to form a gaseous effluent having a concentration thereof below the maximum, and forming a concentration gradient of first gas in the bed progressively decreasing from one end to the other end as the adsorption continues, and an increasing concentration of first gas in the second gas defining a concentration front progressively advancing in the bed from the one end to the other end as sorbent capacity therefor decreases; and forming a temperature front in the sorbent bed in which the temperature of the bed is changing, progressively increasing while adsorption of first gas in the bed continues, and then leveling off and progressively decreasing when adsorption of first gas in the bed ceases; detecting the advance of the temperature front in the bed; and then, when the change in the temperature of the bed has reached a predetermined value corresponding to a selected degree of saturation of the bed with respect to first gas, discontinuing passing the gaseous mixture in contact with the bed before either the temperature front or the concentration front can leave the bed, and the limiting maximum concentration of first gas in the second gas can be exceeded.
Claim 3
Dependent Claim
68 words
A process in accordance with claim 1 which comprises desorbing first gas from the bed by passing purge flow of gas low in concentration of said first gas in contact with the bed and subjecting the bed to an elevated temperature sufficient to desorb said first gas, and/or a pressure below the pressure at which adsorption is effected, and then repeating the adsorption and desorption cycles in sequence.
Claim 4
Dependent Claim
35 words
A process in accordance with claim 1 in which the passing of the gaseous mixture in contact with the bed is discontinued automatically when the temperature front has traveled a predetermined distance through the bed.
Claim 5
Dependent Claim
173 words
Apparatus for reducing the concentration of first gas for example, water vapor, in a mixture thereof with a second gas to below a limiting maximum concentration thereof in the second gas, comprising, in combination, a vessel; a chamber therein for a bed of sorbent having a preferential affinity for the first gas such as water vapor; a line for delivering influent gas at an inlet end of said bed; a line for delivering effluent gas from an outlet end of said bed; temperature sensing means in the bed in a position to sense the temperature thereof to detect the advance of the temperature front at a predetermined point sufficiently far from the end of the bed to prevent the leading edge of the temperature front from leaving the bed; means for giving a signal in response to the reaching of a predetermined temperature change in the bed correlated with the advance of the temperature front through the bed; and means for closing off the influent flow of gas in response to the signal.
Claim 6
Dependent Claim
173 words
Apparatus for reducing the concentration of first gas for example, water vapor, in a mixture thereof with a second gas to below a limiting maximum concentration thereof in the second gas, comprising, in combination, a vessel; a chamber therein for a bed of sorbent having a preferential affinity for the first gas such as water vapor; a line for delivering influent gas at an inlet end of said bed; a line for delivering effluent gas from an outlet end of said bed; temperature sensing means in the bed in a position to sense the temperature thereof to detect the advance of the temperature front at a predetermined point sufficiently far from the end of the bed to prevent the leading edge of the temperature front from leaving the bed; means for giving a signal in response to the reaching of a predetermined temperature change in the bed correlated with the advance of the temperature front through the bed; and means for closing off the influent flow of gas in response to the signal.
Claim 7
Dependent Claim
31 words
Apparatus in accordance with claim 4, wherein the temperature sensor is selected from a thermistor; an integrated circuit temperature transducer; a platinum resistance thermistor; a thermocouple; and a bimetallic temperature switch.
Claim 8
Dependent Claim
42 words
Apparatus in accordance with claim 4 having four temperature transducers in the sorbent bed, one transducer adjacent the top of the sorbent bed, one transducer in the middle of the bed, and the remaining two transducers evenly spaced intermediate these two sensors.
Claim 9
Dependent Claim
72 words
Apparatus in accordance with claim 4 comprising at least two temperature transducers providing input to an analog circuit comprising operational amplifiers and resistors, one output of the analog circuit being a voltage that is proportional to T 2 - , and a second output being proportional to T3 - , a change in slope corresponding to the temperature front at the transducers being shown by comparing the temperatures of the two transducers.
Claim 10
Dependent Claim
29 words
Apparatus in accordance with claim 7, in which the two voltage outputs are compared to preset limits and used to drive simple logic gates to control the gas fractionator.
Claim 11
Dependent Claim
24 words
Apparatus in accordance with claim 7, in which the two voltage outputs are compared to preset limits and used in combination with a microprocessor.
References Cited (Backward Citations)
No citation records indexed.
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