US3815376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and system for the production and purification of helium
Assignee: Airco Inc
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Filing: 1969-07-31
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Granted: 1974-06-11
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Expires: 1989-07-31
Abstract
Abstract An overall process comprising a series of three successive operations for deriving helium from natural gas and purifying it to 99.9969 mol percent, minimum. In the initial operation, the natural gas feed, containing 15 to 40 mol percent of helium, is cooled and flashed in two stages. Both the crude helium product and the vaporized condensate from the flash stages serve to refrigerate the feed stream. The condensate by-product provides commercial grade fuel gas. In the intermediate operation, an input stream having a helium content from 60 to 80 mol percent is enriched to a purity of 85 to 97 mol percent by cooling it to below liquid nitrogen temperature, and passing it through a helium separator. The effluent helium-rich vapor is optionally reheated, then work expanded, and used as a refrigerant for the feed stream. Dissolved helium is removed from the condensate in the helium separator by auxiliary flashing, and returned to the recycle stream, the condensate from the latter stage ultimately serving as a refrigerant. In the final operation, the enriched helium undergoes purification by catalytic action to remove hydrogen. It is then dried, compressed, cooled, passed through several stages of flashing and additional cooling, and through carbon adsorbers to remove the balance of nitrogen. The cold, nearly pure product is finally heat exchanged with a feed stream prior to storage. Condensate from the flashing stages, and liquid from an auxiliary nitrogen system provide refrigeration for the final purification operation.
Inventors
- 👤 A Lofredo
- 👤 A Surowiec
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 00:39
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/08; F25J3/02; F25J3/0204; F25J3/0209; F25J3/0228; F25J3/0257; F25J3/028; F25J3/029; F25J2205/00; F25J2205/40; F25J2205/60; F25J2215/00; F25J2215/30; F25J2270/00; F25J2270/14; F25J2270/42; F25J2270/90; F25J2270/904
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
72 words
A process in accordance with claim 1 comprising three successive operations wherein: said natural gas contains between about 15 and 40 mol percent of helium, said crude helium product contains between about 60 and 80 mol percent of helium, said enriched helium product contains between about 85 and 97 mol percent of helium, and said grade A helium product has an impurity content which is less than about 30 parts per million.
Claim 2
Dependent Claim
75 words
The process in accordance with claim 1 wherein in the second of said operations, the enriched helium vapor from said one flashing stage is passed through a reheating step prior to said work-expansion step for warming up said vapor to a temperature exceeding the condensation temperature of the components of said vapor by more than the expected temperature reduction during said work-expansion step whereby no liquid is formed in said vapor during said work-expansion step.
Claim 3
Dependent Claim
62 words
A process in accordance with claim 1 wherein in the second of said operations said cooling is carried out in two steps: the first said step comprising a heat exchange with multiple streams, including returning enriched helium product and recycle streams, and the second said step comprising a subcooling step in a heat exchange with only the work-expanded enriched helium product stream.
Claim 4
Dependent Claim
76 words
A process in accordance with the first of said operations set forth in claim 1 wherein said by-product condensed hydrocarbons are separated out as one or more streams employed to cool said feed gas stream, each of which hydrocarbon streams may optionally be returned for recycling with said partially helium vapor, wherein said by-product condensed hydrocarbons consist of commercial grade fuel having a heating capacity of between 850 and 950 British Thermal Units per cubic foot.
Claim 5
Dependent Claim
64 words
A process in accordance with claim 1 wherein refrigeration for the cooling Steps in each of said operations is furnished entirely by condensate from the flashing stages and from work expansion in the said operation, with the exception of the final said operation wherein supplementary refrigeration for the cooling steps including refrigeration of said carbon desorbing means is furnished from an auxiliary nitrogen source.
Claim 6
Dependent Claim
30 words
A process in accordance with claim 1 wherein condensate comprising waste nitrogen from said first and second operations is optionally returned with the recycle stream in each of said operations.
Claim 7
Dependent Claim
56 words
A process in accordance with claim 6 wherein the liquid condensate from the additional stage of said second operation and from the later stages of said third operation is nitrogen having a purity in excess of 96 mol percent; and wherein said nitrogen is employed for reactivating (airpurifying) adsorbers in the final one of said operations.
Claim 8
Dependent Claim
82 words
A process in accordance with claim 1 wherein in the final one of said operations said enriched helium feed stream is heated up to a temperature in excess of 200*F prior to dehydrogenation in the presence of a catalyst, the step of deriving fuel gas from the separated stream of condensed hydrocarbons in siad first operation for heating up said feed stream in the preliminary stages of said third operation during the initial period or when said feed stream is hydrogen deficient.
Claim 9
Dependent Claim
269 words
A process for deriving crude helium from natural gas which comprises the steps of: compressing a feed stream comprising said natural gas to about 30 atmospheres pressure, cooling said compressed feed gas stream to below the condensation point of a major portion of hydrocarbons in said feed stream by heat exchange with returning crude helium product and condensate streams, separating out a first stream of condensed hydrocarbons from said feed stream in at least one flashing step and utilizing said condensed hydrocarbons for cooling said feed gas stream, subcooling the vapor from said flashing step to at least about the condensation point of nitrogen in a further heat exchange with returning crude vapor product and condensate streams, stripping the subcooled feed gas stream of helium by flashing in a plurality of successive stripping stages at progressively lower pressures to produce crude helium product vapor from the first of said flash stages and partially helium vapor from the remainder of said flash stages, separating out a stream of condensed hydrocarbons from the last of said successive stripping stages, returning said crude helium product vapor through said heat exchange steps for warming said crude helium vapor, and cooling said compressed feed gas stream, returning and recycling the partially helium vapor obtained from the remainder of said flashing stages, and vaporizing and utilizing the said streams of hydrocarbon condensate from said flashing and stripping stages to provide refrigeration for said heat exchange steps, said streams of returning crude helium, partial helium and hydrocarbon condensate providing adequate internal refrigeration for said crude helium derivation process without the use of an auxiliary refrigeration cycle.
Claim 10
Dependent Claim
237 words
A process in accordance with claim 10 for deriving a crude product containing between 60 and 80 mol percent of helium from natural gas containing between 15 and 40 mol percent of helium wherein: said compressed feed stream is cooled to about -140*F by heat exchange with returning crude helium product and condensate streams, said first stream of condensed hydrocarbons is separated from said feed stream by a pair of successive flashing steps, the first at about 30 atmospheres pressure and the second at about 13.5 atmospheres pressure, the said stream from said second flashing stage is utilized for cooling said feed gas stream, the vapor from said first flashing step is subcooled to a temperature of -254*F in a further heaT exchange with returning crude vapor product and condensate streams, the subcooled feed gas stream is stripped of helium by flashing in a plurality of successive stages in which: the first of said stages is at a pressure of 30 atmospheres, the second of said stages which receives the liquid condensate from the first of said stages is at a pressure just in excess of 13 atmospheres, the third of said stages which receives the condensate from the second of said stages is at a pressure of just in excess of 5 atmospheres, and said second stream of condensed hydrocarbons is separated out from the last of said successive stripping stages at about 5.3 atmospheres pressure.
Claim 11
Dependent Claim
182 words
A process for enriching a crude helium feed stream which comprises the steps of: compressing said feed stream of crude helium to about 80 atmospheres pressure, cooling said feed stream in a heat exchange with enriched helium vapor product, liquid condensate, and recycle streams to at least about the condensation temperature of nitrogen, directing the said feed stream through at least one flashing stage for separating out enriched helium vapor from liquid condensate, work-expanding the said enriched helium vapor from said one flashing stage, directing the work-expanded enriched helium vapor through at least one heat exchange step with said feed stream to provide an enriched helium product stream at a temperature above 0*F, directing the condensate from said one flashing stage through at least one additional flashing stage for stripping the helium from said condensate, directing the vapor product of said additional flashing stage through at least one heat exchange step for cooling said feed stream, subsequently recompressing said last-named vapor product for recycling with said feed stream, and utilizing the condensate from said additional flashing stage for refrigerating said feed stream.
Claim 12
Dependent Claim
71 words
A process in accordance with claim 12 wherein the enriched helium vapor from said one flashing step is passed through a reheat step prior to said work-expansion step for warming up the said vapor to a temperature exceeding the condensation temperature of the components of said vapor by more than the expected reduction in temperature in said workexpansion process, whereby no liquid is formed in said vapor during said work-expansion step.
Claim 13
Dependent Claim
54 words
A process in accordance with claim 12 wherein said cooling is carried out in two steps: the first said step comprising a heat exchange with multiple streams including returning product and recycle streams, and the second said step comprising a subcooling step in a heat exchange with only the work-expanded enriched helium product stream.
Claim 14
Dependent Claim
483 words
In a process for enriching a crude helium feed stream containing between about 60 and 80 mol percent of helium to an enriched product containing between 85 and 97 mol percent helium which comprises the steps of: compressing said feed stream of crude helium to about 80 atmospheres pressure at near ambient temperature, cooling said feed stream in a heat exchange with enriched helium vapor product, liquid condensate, and recycle streams to at least about the condensation temperature of nitrogen, and directing said feed stream through one high pressure flashing stage for separating out enriched helium vapor from liquid condensate, and directing the condensate from said high pressure flashing stage comprising nearly 96 mol percent nitrogen and small amounts of hydrogen and methane through at least one additional low pressure flashing operation including a reboiling operation for stripping helium from said condensate: during said cooling step dividing said feed stream into two components, a major component comprising at least about 95 percent by volume of the flow, and a minor component comprising less than about 5 percent by volume of the flow, coolinG said major component in a heat exchange with returning product and waste streams to at least about the condensation temperature of nitrogen, partially cooling said minor component in a heat exchange with a returning recycle stream, and subsequently further cooling said minor component in a heat exchange with evaporating liquid condensate in said reboiling operation in said additional flashing stage to at least about the condensation temperature of liquid nitrogen, the two said cooled component streams being combined at about said last-named temperature and directed as a combined stream to said high pressure flashing stage in which said enriched helium vapor is separated out, reheating said enriched helium vapor from said high pressure flashing stage to a temperature at least above the boiling point of the highest boiling component thereof in a heat exchange within the major component of said feed stream for substantially eliminating liquid therefrom, subsequently work expanding said enriched helium vapor to about 60 atmospheres pressure at a temperature of about -320*F, directing said work-expanded enriched helium vapor through at least one heat exchange with the major component of said feed stream in which said enriched vapor is warmed with a slight reduction in pressure to provide a product having a near ambient temperature, directing the vapor product from said additional flashing operation, containing about 30 mol percent of helium, and a balance of nitrogen, hydrogen, and trace hydrocarbons through at least one heat exchange step with a component of said feed stream prior to passing for recompression and recycling in said system, utilizing the condensate consisting of more than 96 mol percent nitrogen derived from said additional flashing operation for refrigerating said feed stream, and optionally merging the said condensate with the vapor product from said additional flashing operation for recompression and recycling in said system.
Claim 15
Dependent Claim
71 words
The combination in accordance with claim 15 wherein the level of condensate in said reboiler is maintained at a preselected level by syphoning the said condensate from the bottom of the reboiler through a syphon providing a liquid head slightly above the said preselected liquid level in said reboiler; and wherein the pressure at the head of said syphon is regulated in accordance with the output vapor pressure from said reboiler.
Claim 16
Dependent Claim
290 words
A process for enriching a crude helium stream containing between 60 and 80 mol percent of helium to an enriched product containing between 85 and 97 mol percent of helium which comprises the steps of: compressing said crude helium feed stream to about 80 atmospheres pressure at near ambient temperature, cooling said crude helium feed stream in a heat exchange with returning enriched helium vapor product, liquid condensate and recycle streams to at least about the condensation temperature of nitrogen, subsequently directing said cooled feed stream through a high pressure flashing stage where enriched helium vapor which consists of at least 95 mol percent of the helium is separated from liquid condensate, reheating said vapor from said high pressure flashing stage to a temperature at least above the boiling point of the highest boiling component thereof, turbo-expanding said reheated enriched helium vapor to about 60 atmospheres pressure, heating said turbo-expanded enriched helium vapor in said heat exchange with said feed stream to provide an enriched helium product at near ambient temperature, further flashing the liquid condensate comprising about 95 mol percent nitrogen derived from said high pressure flashing stage in a helium stripper at about 1 1/2 atmospheres pressure for stripping the helium from said condensate, and passing the condensate from said further flashing stage consisting of about 97 mol percent nitrogen Through heat exchange means for cooling said feed stream and out to the atmosphere at near ambient temperature, passing the said stream of vapor derived from said helium stripper comprising about 30 mol percent helium in heat exchange for cooling said feed stream and warming said vapor to near ambient temperature at near atmospheric pressure, and subsequently recompressing said last-named vapor product for recycling with said feed stream.
Claim 17
Dependent Claim
43 words
The process in accordance with claim 17 wherein said liquid condensate from said further flashing stage consisting of about 97 mol percent nitrogen is optionally combined with said stream of vapor derived from said helium stripper for recompression and recycling in said system.
Claim 18
Dependent Claim
51 words
The process in accordance with claim 17 wherein: said feed stream is cooled to -316*F in at least two heat exchange steps, the first said step is a heat exchange with returning product and recycle streams, and the second said step is a heat exchange with an expanded returning product stream.
Claim 19
Dependent Claim
758 words
A process for preparing grade A helium from an enriched helium feed stream containing 85 to 95 mol percent of helium comprising in combination the following steps: deriving said feed stream at about 60 atmospheres pressure and ambient temperature, heating said enriched helium feed stream to above 220*F prior to partly dehydrogenating said feed stream together with a recycle stream including at most about 20 mol percent oxygen in the presence of a catalyst to convert all but a small excess of the hydrogen in said stream to water vapor, passing said partly dehydrogenated stream through a bed containing a reducing agent for removing the remaining hydrogen from said stream, drying and compressing said dehydrogenated stream to 185 atmospheres, separating said compressed stream into two components, each of said components being cooled by heat exchange with returning product and recycle streams to about -280*F, alternately flashing and further cooling said compressed dehydrogenated helium stream through a plurality of flashing and cooling stages in heat exchange with boiling liquid nitrogen for condensing nitrogen and hydrocarbon impurities from said stream, said stages comprising: passing said partially cooled feed stream through a first high pressure flashing stage, deriving helium vapor between about 92 and 96 mol percent pure from said first flashing stage, cooling said helium vapor from said first flashing stage to about -315*F in a heat exchange with returning vapor and product streams, and a further heat exchange in boiling liquid nitrogen in a first liquid nitrogen stage, passing said cooled partially purified helium through a second high pressure flashing stage at about -315*F, deriving from said second flashing stage a helium vapor having a purity in excess of 98 mol percent, containing less than about 2 mol percent nitrogen impurity, cooling the helium vapor stream from said second flashing stage to a temperature of about -340*F in a heat exchange with reheating vapor from a third high pressure flashing stage and boiling liquid nitrogen in a second liquid nitrogen stage, passing said stream through said third high pressure flashing stage at a temperature of -340*F, deriving helium vapor from said third flashing stage which exceeds 99 mol percent purity containing less than one mol percent nitrogen, reheating the purified vapor from said third flashing stage up to a temperature of about -320*F in a heat exchange with cooling vapor from said second flashing stage, recooling said vapor with boiling liquid nitrogen in a repass through said first liquid nitrogen stage, directing said reheated vapor at a pressure of at least about 82 atmospheres through an on-cycle one of a plurality of vessels comprising carbon adsorbing means, where trace amounts of hydrogen, nitrogen, and hydrocarbons are adsorbed, said adsorbing means assuming on-cycle and off-cycle connections in alternation, deriving a product stream of nearly 100 mol percent pure helium from said carbon adsorbing means, passing said product stream through a heat exchange with feed streams being cooled wherein said product stream is warmed up to a temperature of about 80*F at a pressure of about 182 atmospheres, deriving condensates from said first high pressure flashing stage and flashing said condensates through a fourth flashing stage at 1 1/2 atmospheres pressure and -320*F, wherein the condensate from said fourth flashing stage includes in excess of 95 mol percent nitrogen, passing the condensate from said fourth flashing stage in heat exchange with said feed stream for cooling said feed stream and vaporizing and heating said condensate up to about 80*F prior to venting said vaporized condensate, deriving condensates from said second and third flashing stages containing in excess of 96 mol percent of nitrogen with more than 2 mol percent helium and less than 0.5 mol percent methane, directing the condensates from said second and third flashing stages to a fifth stage flash vessel employed as a helium stripper maintained at a pressure of about 1 1/2 atmospheres, returning the vapor from said helium stripper containing in excess of 20 mol percent of helium through heat exchange with said feed stream for recycling through said system, deriving the condensate from said helium stripper (fifth stage) including in excess of 99 mol percent of liquid nitrogen and less than 0.5 mol percent methane, and passing said condensate in heat exchange with feed streams undergoing cooling, deriving nitrogen from an ancillary off-site source at a pressure of about 41 atmospheres and a temperature above ambient, and liquefying and using said nitrogen stream for refrigerating the on-cycle one of said adsorbers, and for refrigerating the vapor streams from said first, second and third flashing stages.
Claim 20
Dependent Claim
81 words
The process in accordance with claim 20 wherein the method of purging the carbon bed of an off-cycle one of said adsorbing vessels of impurities adsorbed during said on-cycle connection which comprises: deriving a small component of hot compressed feed stream prior to after cooling, passing said component through the carbon bed of said off-cycle vessel, and subsequently passing the purged gases into the stream under purification for at least a partial repass through said process for preparing grade A helium.
Claim 21
Dependent Claim
246 words
In the process in accordance with claim 20 providing refrigerant for the refrigeration coil of the on-cycle vessel of said plurality, and the coils of said boiling liquid nitrogen stages by the steps of: deriving high pressure gaseous nitrogen from an off-cycle source at about 41 atmospheres pressure, cooling the said high pressure nitrogen streams in two components in heat exchange with returning low pressure nitrogen streams, the major said high pressure component being cooled in said heat exchange operation to about -170*F and subsequently work-expanded to a temperature of about -310*F at just above atmospheric pressure prior to returning in said heat exchange with said cooling high pressure streams, the minor said high pressure component being cooled to about -275*F in said heat exchange with returning low pressure streams, adiabatically expanding said cooled high pressure minor component to about atmospheric pressure and a temperature of about -310*F in a pressure-controlled valve, subsequently flashing said cooled minor component to separate the liquid from the vapor, the vapor from said Flashing step returning in said heat exchange operation and merging with other returning low pressure streams, and the liquid from said flashing step passing for evaporation in the refrigeration coils of said on-cycle carbon adsorber, and the coils of said boiling liquid nitrogen stages, the resultant nitrogen vapor being returned for heat exchange with said high pressure nitrogen streams prior to being optionally returned to said off-cycle nitrogen source for refrigeration in other parts of said system.
Claim 22
Independent Claim
1226 words
A system for converting a feed stream comprising natural gas to grade A purity helium which comprises in combination: a first unit for converting a feed stream comprising natural gas to crude helium which comprises in combination: means for compressing said natural gas feed stream to about 30 atmospheres pressure, a first heat exchanger for cooling said natural gas feed stream in a heat exchange with returning product and recycle streams and condensed liquid streams, means for separating out the condensed hydrocarbons from said natural gas feed stream comprising a flash drum having a plurality of stages at progressively lower pressures, a second heat exchanger connected to receive vapor from the first flash stage of said plurality of flashing stages for subcooling said vapor in a heat exchange with returning product and recycle streams, means comprising a helium stripper having a first stage at high pressure, and a plurality of subsequent stages at progressively lower pressures for separating a major portion of the helium vapor from said subcooled vapor, means for deriving crude helium product vapor from said first stage of said helium stripper and for returning said crude product vapor through said heat exchangers to means for transferring said crude helium product to the second unit of said system, means for deriving recycle vapor including a substantial component of helium from said subsequent stages of said helium stripper and for returning said recycle vapor through said heat exchangers, means for compressing said recycle vapor and returning said vapor to said feed stream, means for deriving condensed hydrocarbons from said plurality of flashing stages and returning a stream of said condensed hydrocarbons through said first heat exchanger for refrigeration by vaporization, and to storage, and means for deriving a stream comprising a high percentage of condensed hydrocarbons from the stages of said helium stripper and returning said stream through said first and second heat exchangers for refrigerating said heat exchangers; a second unit for converting said feed stream comprising crude helium to enriched helium, which comprises in combination: means for deriving a crude helium feed stream compressed to a pressure of about 80 atmospheres, heat exchanger means for cooling said crude helium feed stream to a temperature below the condensation point of liquid nitrogen, helium separation means connected to receive the cooled crude helium feed stream from said heat exchanger means for separating out enriched helium vapor from said feed stream, work-expansion means connected to receive and workexpand the enriched helium vapor from said helium separator, a system of conduits connected to receive the workexpanded enriched helium vapor from said work expansion means and to direct said enriched helium vapor product to return through said heat exchanger means for cooling said crude helium feed stream, and means for transferring said enriched helium product to the third unit of said system, a conduit connected to the bottom of said helium separator for deriving liquid condensate therefrom, auxiliary separation means connected to receive the liquid condensate from said helium separator, means for deriving the partly helium vapor from said auxiliary separation means and returning said vapor through said heat exchanger means for cooling said crude helium feEd stream, compressing means connected to said heat exchanger means for compressing and returning said partly helium vapor to said crude helium feed stream for recycling in said system, and means for deriving the primarily liquid condensate from said auxiliary separation means and for directing said condensate to pass through said heat exchanger means for evaporation therein to cool said crude helium feed stream; and a third unit for converting a feed stream comprising enriched helium to helium of grade A purity, which comprises in combination: means for deriving an enriched helium feed stream compressed to a pressure of about 60 atmospheres, means comprising a first heat exchanger for heating said feed stream up to a temperature in excess of 220*F, a source of a stream containing about 20 mol percent of oxygen for combining with said helium enriched feed stream, means comprising a catalytic dehydrogenator connected to receive said enriched feed stream in combination with said oxygen-containing stream for converting a major portion of the hydrogen in said feed stream to water vapor, means for receiving the output of said dehydrogenator comprising a chemical hydrogen adsorber, said first heat exchanger connected to cool the output of said adsorber in a heat exchange with the enriched helium feed stream entering said dehydrogenator, means for drying said dehydrogenated stream, compressing means connected to compress said dried stream to about 185 atmospheres pressure, means comprising an aftercooler connected to said compressing means, a second and third heat exchanger connected in tandem to receive said compressed dehydrogenated enriched helium stream in two components and to cool said stream components to below the condensation temperature of liquid nitrogen in a heat exchange with returning purified helium product, recycle, and condensate streams, flashing means comprising a first stage flash drum, for flashing the recombined components of said cooled enriched compressed dehydrogenated helium stream through a plurality of stages to separate out higher boiling liquid condensates from the helium containing vapor in said stream, means for deriving the nearly purified helium vapor from said first stage flash drum and directing said helium vapor for a partial repass through said second and third heat exchangers, a first liquid nitrogen boiler connected to receive and further cool the merged streams derived from repass of said second and third heat exchangers, means comprising a second stage flash drum connected to receive the output from said first nitrogen boiler and to separate the partially purified helium vapor from the condensate in said stream, a fourth heat exchanger for receiving and slightly cooling the helium vapor from said second stage flash drum, a second liquid nitrogen boiler connected to receive the slightly cooled helium vapor from said fourth heat exchanger and to further cool said vapor to a temperature of about -340*F, a third stage flash drum including means for separating the liquid condensate from helium vapor at a temperature of about -340*F, means including said fourth heat exchanger for slightly reheating the output of said third stage flash drum, nitrogen adsorbing means comprising a plurality of vessels each equipped with a bed of comminuted carbon connectable in alternation in respective on-cycle and off-cycle positions wherein said on-cycle vessel is connected to receive the nearly purified vapor from said third stage flash drum and said liquid nitrogen boiler for adsorbing residual impurities in said vapor including nitrogen, means for deriving the helium product vapor of grade A purity from said nitrogen adsorber and directing said purified product vapor through said second and third heat exchangers in tandem to the output of said system, auxiliary to the principal purificatIon system, said fourth stage flash drum maintained at a pressure of slightly over one atmosphere and at a temperature not exceeding about -320*F for receiving and flashing the liquid condensate from said first stage flash drum, means for deriving liquid condensate containing in excess of about 95 mol percent of nitrogen from said fourth stage flash drum and passing said liquid condensate through said second heat exchanger means for evaporation and heat exchange cooling said compressed enriched helium feed stream, wherein said condensate is heated up to above ambient temperature, venting means connected to said second heat exchanger for venting said vaporized condensate from said
Claim 23
Dependent Claim
119 words
The combination in accordance with claim 23 wherein said first unit is designed to convert a feed stream of natural gas containing between 15 and 40 mol percent of helium to crude helium containing between 60 and 80 mol percent of helium; wherein said second unit is designed to convert a feed stream of crude helium containing between 60 and 80 mol percent of helium and to enriched helium containing between 85 and 97 mol percent of helium, and wherein said third unit is designed to convert a feed stream of enriched helium containing between 85 and 97 mol percent of helium to helIum of grade A purity having an impurity content not exceeding about 30 parts per million.
Claim 24
Dependent Claim
100 words
The combination in accordance with claim 23 wherein the stream of condensed hydrocarbons in said first unit has a heating capacity of between about 850 and 950 British Thermal Units per hour, and wherein in said third unit for preparing grade A helium, said means for heating said enriched helium feed stream to in excess of 220*F includes a heater for application to said enriched helium feed stream before said first heat exchanger is warmed up, said heater including means for deriving a fuel comprising at least a portion of the stream of said condensed hydrocarbons from said first unit.
Claim 25
Dependent Claim
56 words
The combination in accordance with claim 23 wherein said source of a stream containing about 20 mol percent of oxygen includes adsorbing means for adsorbing water vapor and carbon dioxide from said stream, and means for reactivating said adsorbing means comprising a stream of waste nitrogen which is a by-product of said second or third units.
Claim 26
Dependent Claim
31 words
The combination in accordance with claim 23 comprising means for optionally returning waste nitrogen from said first and second operations in combination with the recycle stream in each of said operations.
Claim 27
Independent Claim
284 words
A system for converting a feed stream comprising natural gas to crude helium without auxiliary means for providing internal refrigeration, which comprises, in combination: means for compressing said feed stream to about 30 atmospheres pressure, a first heat exchanger for cooling said feed stream in a heat exchange with returning product, recycle, and condensed liquid streams, means for separating out the condensed hydrocarbons from said feed stream comprising a flash drum having a plurality of stages at progressively lower pressures, a second heat exchanger connected to receive vapor from the first flash stage of said plurality of flashing stages for subcooling said vapor in a heat exchange with returning product and recycle streams, means comprising a helium stripper having a first stage at high pressure, and a plurality of subsequent stages at progressively lower pressures for separating a major portion of the helium vapor from said subcooled vapor, means for deriving crude helium vapor from said first stage of said helium stripper and for returning said vapor through said heat exchangers to storage, means for deriving recycle vapor including a substantial component of helium from said subsequent stages of said helium stripper and for returning said recycle vapor through said heat exchangers, means for compressing said recycle vapor and returning said vapor to said feed stream, means for deriving a first stream comprising hydrocarbon condensate from said plurality of flashing stages and returning said first stream of condensate through said first heat exchanger for refrigeration and to storage, and means for deriving a second stream of hydrocarbon condensate from the stages of said helium stripper and returning said second stream of condensate through said first and second heat exchangers for refrigerating said heat exchangers.
Claim 28
Dependent Claim
57 words
A system for converting natural gas into crude helium in accordance with claim 28 which comprises means for optionally combining said first and second streams of hydrocarbon condensate in said first heat exchanger into a by-product stream consisting of commercial grade fuel having a heating capacity of between 850 and 950 British Thermal Units per cubic foot.
Claim 29
Dependent Claim
34 words
A system for converting natural gas into crude helium in accordance with claim 29 which comprises means for optionally combining and returning one or both of said streams of hydrocarbon with said recycle vapor.
Claim 30
Dependent Claim
155 words
A system in accordance with claim 28 for converting a feed stream comprising natural gas including between 15 and 40 mol percent of helium to crude helium having a purity of 60 to 80 moL percent wherein said flash drum has at least two stages, the first of said stages being maintained at a pressure of about 30 atmospheres and a temperature of about -148*F, and the second of said stages being maintained at a pressure slightly in excess of 13 atmospheres at a temperature below -169*F; and wherein said helium stripper comprises at least three stages, the first stage being maintained at a pressure of about 30 atmospheres and a temperature of about -258*F, the second said stage being maintained at a pressure slightly in excess of 13 atmospheres at said temperature, and the third said stage being maintained at a pressure slightly in excess of 5 atmospheres at a temperature of about -264*F.
Claim 31
Independent Claim
251 words
A system for converting a feed stream comprising crude helium to enriched helium which comprises in combination: means for deriving a crude helium feed stream compressed to a pressure of in excess of about 80 atmospheres, heat exchanger means for cooling said crude helium feed stream to a temperature below the condensation point of liquid nitrogen, means comprising a helium separator connected to receive the cooled crude helium feed stream from said heat exchanger means for separating out enriched helium vapor from said feed stream, work-expansion means connected to receive and work-expand the enriched helium vapor from said helium separator, a system of conduits connected to receive the work-expanded enriched helium vapor from said work expansion means and direct said enriched helium vapor to return through said heat-exchanger means for cooling said crude helium feed stream, a conduit connected to the bottom of said helium separator for deriving liquid condensate therefrom, auxiliary separation means connected to receive the liquid condensate from said helium separator, means for deriving the partly helium vapor from said auxiliary separation means and returning said vapor through said heat exchanger means for cooling said feed stream, compressing means connected to said heat exchanger means for compressing and returning said partly helium vapor to said feed stream for recycling in said system, and means for deriving said liquid condensate comprising primarily nitrogen from said auxiliary separation means and directing said condensate to pass through said heat exchanger means for evaporation therein to cool said crude helium feed stream.
Claim 32
Dependent Claim
33 words
The combination in accordance with claim 32 which comprises means for optionally returning the evaporated condensate comprising primarily nitrogen from said suxiliary separation means through said compression means for recycling in said system.
Claim 33
Dependent Claim
79 words
The combination in accordance with claim 32 wherein a reheat cycle is connected ahead of said work-expansion means, said reheat cycle including a portion of said heat exchanger means for receiving the enriched helium vapor from said helium separator and reheating said vapor to a temperature exceeding the condensation temperature of any of the components of said vapor by more than the expected reduction in temperature in said work-expansion means, whereby no liquid is formed in said work-expansion means.
Claim 34
Independent Claim
526 words
A system for converting a feed stream comprising crude helium having a purity of 60 to 80 mol percent to enriched helium having a purity of between 85 and 97 mol percent which comprises in combination: means for deriving a crude helium feed stream compressed to in excess of about 80 atmospheres at an initial temperature in excess of about 40*F, conduit means for dividing said compressed crude helium feed stream into two components, one said component comprising in excess of about 95 percent by volume and the other said component comprising less than about 5 percent by volume, heat exchanger means for cooling said crude helium feed Stream to a temperature below the condensation temperature of liquid nitrogen, said heat exchanger means comprising: a first heat exchanger connected to receive and cool said minor component in a heat exchange with a returning recycle stream, means connected in series with said first heat exchanger comprising a reboiler coil interposed in the bottom of a helium stripper, a second heat exchanger connected to receive and cool said major component in a heat exchange with returning enriched helium product and condensate streams, means for combining the respective two crude helium components from said reboiler coil and said second heat exchanger at a temperature of about -316*F, means comprising said helium separator connected to receive the combined cooled crude helium feed stream from said heat exchanger means for separating out enriched helium vapor from said crude feed stream, work-expansion means comprising a turbo-expander connected to receive the enriched helium vapor from said helium separator and to work expand said vapor, a system of conduits connected to receive the work-expanded enriched helium vapor from said work expansion means and direct said enriched helium vapor to return through said heat exchanger means for cooling said crude helium feed stream, a conduit connected to the bottom of said helium separator for deriving liquid condensate therefrom, auxiliary separation means connected to receive the liquid condensate from said helium separator, wherein said auxiliary separation means comprises: a first auxiliary flash drum maintained at about 2 atmospheres pressure, a second auxiliary flash drum maintained at slightly above atmospheric pressure and serving as said helium stripper connected to receive the liquid condensate from said first auxiliary flash drum for boiling in heat exchange with the cooled feed stream in said reboiler coil to separate out any vapor including helium vapor therefrom, means for deriving a partly helium vapor from said auxiliary flashing separation means comprising conduit means connected between the tops of said first and second auxiliary flash drums and said first heat exchanger for supplying refrigeration to said heat exchanger, compressing means connected to said heat exchanger means for compressing and returning said partly helium vapor to said feed stream for recycling in said system, and means for deriving said primarily liquid condensate comprising primarily nitrogen from said auxiliary separation means and directing said condensate to pass through said heat exchanger means for evaporation to cool said crude helium stream, said means comprising conduit means connected between the bottom of said second auxiliary flash drum and said second heat exchange means for supplying refrigeration thereto.
Claim 35
Dependent Claim
80 words
The combination in accordance with claim 35 wherein means comprising a syphon is connected to the bottom of said second auxiliary flash drum serving as said helium stripper, said syphon constructed and arranged to maintain a preselected liquid level in said helium stripper-reboiler, a pressure-actuated valve being connected between the vapor output of said helium stripper and the head of said syphon for regulating the pressure in said syphon in accordance with the output vapor pressure of said helium stripper.
Claim 36
Dependent Claim
86 words
The combination in accordance with claim 35 wherein: a three-way valve is connected to receive streams from the cold ends of each of said first and second heat exchangers and to supply a merged stream to the input of said helium separator, and means for controlling the ratio of the streams received from the path including said first heat exchanger and said reboiler coil, and the path including said second heat exchanger in accordance with the temperature differential between the warm ends of said heat exchangers.
Claim 37
Dependent Claim
73 words
The combination in accordance with claim 35 wherein a reheat cycle is connected aHead of said turboexpander, said reheat cycle being connected through a portion of said second heat exchanger for receiving the enriched helium vapor from said helium separator and reheating said vapor to a temperature exceeding the condensation temperature of any of the components of said vapor by more than the expected reduction in temperature of said vapor in said turboexpander.
Claim 38
Dependent Claim
183 words
A system in accordance with claim 38 for converting crude helium having a purity of 60 to 80 mol percent to enriched helium having a purity of between 85 and 97 mol percent: wherein said heat exchanger means is constructed to cool said feed stream to a temperature of about -315*F in heat exchange with returning enriched helium product, recycle, and condensate streams, wherein said work expansion means comprises a turboexpander for work expanding said enriched helium product to about 60 atmospheres pressure, wherein said auxiliary separation means comprises a single helium stripper connected to receive the condensate from said helium separator, said stripper maintained at an internal pressure of slightly above 5 atmospheres and including packing means for separating liquid from vapor in said stripper, said stripper including a bayonet heater connected to a source of energizing power for reboiling liquid condensate collected in the bottom of said stripper, and means for separately returning the liquid condensate and partially helium vapor from said helium stripper through said heat exchanger means, and for returning said partially helium vapor to said compressor for recycle.
Claim 39
Dependent Claim
68 words
The combination in accordance with claim 35 wherein said heat exchanger means comprises a single heat exchanger for cooling said feed stream in heat exchange with enriched helium product vapor, partly helium vapor, and liquid condensate from said helium stripper, wherein the said single heat exchanger includes a reheat coil connected to receive and partly reheat said enriched product vapor from said helium separator ahead of said turboexpander.
Claim 40
Dependent Claim
74 words
A system in accordance with claim 35 wherein said heat exchanger means comprises a first heat exchanger for cooling said crude helium feed stream in heat exchange with expanded enriched helium product vapor and a second heat exchanger interposed between said first heat exchanger and said helium separator in the path of said cooled feed stream for subcooling said crude helium feed stream in a heat exchange with enriched helium product from said turboexpander.
Claim 41
Independent Claim
1016 words
A system for preparing grade A helium from an enriched helium feed stream which comprises in combination: means for deriving an enriched helium feed stream compressed to a pressure of about 60 atmospheres, means comprising a first heat exchanger for heating said feed stream up to a temperature in excess of 220*F, a source of a stream containing about 20 mol percent of oxygen for combining with said helium enriched feed stream, means comprising a catalytic dehydrogenator connected to receive said enriched feed stream in combination with said oxygen containing stream for converting a major portion of the hydrogen in said feed stream to water vapor, means for receiving the output of said dehydrogenator comprising a chemical hydrogen adsorber, said first heat exchanger connected to cool the output of said adsorber in a heat exchange with the enriched helium feed stream entering said dehydrogenator, means for drying said dehydrogenated stream, compressing means connected to compress said dried stream to about 185 atmospheres pressure, means comprising an aftercooler following said compressing means, a second and third heat exchanger connected in tandem to receive said compressed dehydrogenated enriched helium stream in two components and to cool said stream components to below the condensation temperature of liquid nitrogen in a heat exchange with returning purifiEd helium product, recycle, and condensate streams, flashing means, comprising a first stage flash drum, for flashing the recombined components of said cooled enriched compressed dehydrogenated helium stream through a plurality of stages to separate out higher boiling liquid condensates from the helium-containing vapor in said stream, means for deriving the nearly purified helium vapor from said first stage flash drum and directing said helium vapor for a partial repass through said second and third heat exchangers, a first liquid nitrogen boiler connected to receive and further cool the merged streams derived from repass of said second and third heat exchangers, means comprising a second stage flash drum connected to receive the output from said first nitrogen boiler and to separate the partially purified helium vapor from the condensate in said stream, a fourth heat exchanger for receiving and slightly cooling the helium vapor from said second stage flash drum, a second liquid nitrogen boiler connected to receive the slightly cooled helium vapor from said fourth heat exchanger, and to further cool said vapor to a temperature of about -340*F, a third stage flash drum including means for separating the liquid condensate from helium vapor at a temperature of about -340*F, means including said fourth heat exchanger for slightly reheating the output of said third stage flash drum, nitrogen adsorbing means comprising a plurality of vessels each equipped with a bed of comminuted carbon connectable in alternation in respective on-cycle and off-cycle positions, wherein said on-cycle vessel is connected to receive the nearly purified vapor from said third stage flash drum and said liquid nitrogen boiler for adsorbing residual impurities in said vapor including nitrogen, means for deriving the purified helium product vapor from said nitrogen adsorber and directing said purified product vapor through said second and third heat exchangers in tandem to the output of said system, auxiliary to the principal purification system, said fourth stage flash drum maintained at a pressure of slightly over one atmosphere at a temperature of about -320*F for receiving and flashing the liquid condensate from said first stage flash drum, means for deriving liquid condensate containing in excess of about 95 mol percent of nitrogen from said fourth stage flash drum and passing said liquid condensate through said second heat exchanger means for evaporation to cool said compressed enriched helium feed stream, wherein said condensate is heated up to near ambient temperature, venting means connected to said second heat exchanger for venting said vaporized condensate from said system, means for deriving the condensates from said second and third stage flash drums containing in excess of about 96 mol percent of nitrogen and more than 2 mol percent of helium, means including a fifth-stage vessel functioning as a helium stripper for receiving said condensates from said second and third flashing stages, said helium stripper maintained at slightly over one atmosphere pressure at a temperature of less than about -320*F for stripping the remaining helium from said condensates, means connected to said helium stripper for returning the partially helium vapor from said helium stripper through said second heat exchanger for recycling through said system, and means for deriving the condensate from said helium stripper consisting of about 99 mol percent of liquid nitrogen and passing said condensate through said third heat exchanger for evaporation to cool one component of said cooling compressed helium feed stream, wherein said condensate is heated up to near ambient temperature, means for deriving any condensate from said fourth stage flash drum consisting of at least about 95 mol percent of liquid nitrogen and such condensate from said heliuM stripper as is required for heat balance in said second heat exchanger, and passing said condensate through said second heat exchanger for evaporation and heat exchange with the other component of said cooling compressed helium feed stream, wherein said condensate is heated up to about ambient temperature, venting means connected to receive the evaporated condensate from said second heat exchanger for venting said last-named evaporated condensate consisting of nitrogen having a purity of at least about 95 mol percent, an off-site source of nitrogen maintained at a pressure of about 41 atmospheres, means comprising a nitrogen liquefaction circuit for deriving a stream of nitrogen gas from said off-site source at said last-named pressure at near ambient temperature and converting said stream to liquid nitrogen and means for directing the said liquefied nitrogen to the coil of said on-cycle adsorbing means for refrigerating said means at least during the on-cycle connection thereof, and to said liquid nitrogen boilers for refrigerating the partially purified helium stream, and means connected to receive the evaporated condensate from said third heat exchanger for returning at least a part of the evaporated condensate consisting of nitrogen having a purity of about 99 mol percent to said off-site nitrogen source to make up losses.
Claim 42
Dependent Claim
139 words
In a system in accordance with claim 42 for preparing grade A helium having an impurity content not exceeding about 30 parts per million from an enriched helium feed stream containing between 85 and 97 mol percent helium, means for purging the carbon bed of an off-cycle one of said carbon adsorbing means which comprises in combination a purge connection to said compressing means ahead of said aftercooler for deriving from said compressing means a small component of hot compressed feed stream, a system of valves for alternatively connecting said purge connection to the off-cycle one of said carbon adsorbing means, and means simultaneously connectable to said off-cycle adsorbing means for venting the purged gases into said compressed feed stream for at least a partial repass through said system commencing just ahead of said second and third heat exchangers.
Claim 43
Dependent Claim
353 words
In a system in accordance with claim 42 wherein said nitrogen liquefaction system comprises in combination: a heat exchanger connected to said off-site source to receive a high pressure stream of nitrogen gas from said off-site source, at a pressure of about 41 atmospheres at least at ambient temperature, and to cool said stream in two components in heat exchange with low pressure nitrogen streams returning through said heat exchanger, means comprising a turboexpansion device connected to receive the major component of said high pressure nitrogen stream after partial cooling in said heat exchanger to about -170*F, and to expand said stream to about atmospheric pressure, and to further cool said component to a temperature of about -310*F, conduit means for returning said cooled low pressure major stream through said heat exchanger for cooling said high pressure streams, means comprising a pressure-controlled expansion valve for receiving the minor high pressure component of said stream cooled to about -275*F at a pressure of about 40 atmospheres and expanding said component to a pressure just above atmospheric pressure at a temperature of about -310*F, a flash drum connected to said valve to receive said minor stream after expansion and separate the vapor phase from the liquid phase in said stream, conduit means connected between the upper portion of said flash drum and said conduit means for returning said major stream for returning the vapor portion of said minor component through said heat exchanger, conduit means connected between the lower end of said flash drum and the refrigeration coils of at least the on-Cycle one of said carbon adsorbers for supplying refrigerant to said coils, conduit means connected between the lower end of said flash drum and the coils of said liquid nitrogen boilers for supplying refrigerant to said boilers, conduit means connected to the refrigeration coils of said carbon adsorber and to the refrigeration coils of said nitrogen boilers for returning the evaporated nitrogen from said coils through said heat exchanger, and means for optionally returning said evaporated nitrogen to said off-cycle nitrogen source or to said system for recycle with the stream under purification.
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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) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |