CN1677040A - Process and apparatus for the cryogenic separation of air - Google Patents
Process and apparatus for the cryogenic separation of air Download PDFInfo
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- CN1677040A CN1677040A CN200510068588.5A CN200510068588A CN1677040A CN 1677040 A CN1677040 A CN 1677040A CN 200510068588 A CN200510068588 A CN 200510068588A CN 1677040 A CN1677040 A CN 1677040A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04406—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system
- F25J3/04418—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system with thermally overlapping high and low pressure columns
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
- F25J3/04254—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using the cold stored in external cryogenic fluids
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
- F25J3/04254—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using the cold stored in external cryogenic fluids
- F25J3/0426—The cryogenic component does not participate in the fractionation
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04406—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system
- F25J3/04424—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system without thermally coupled high and low pressure columns, i.e. a so-called split columns
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2200/00—Processes or apparatus using separation by rectification
- F25J2200/50—Processes or apparatus using separation by rectification using multiple (re-)boiler-condensers at different heights of the column
- F25J2200/54—Processes or apparatus using separation by rectification using multiple (re-)boiler-condensers at different heights of the column in the low pressure column of a double pressure main column system
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2210/00—Processes characterised by the type or other details of the feed stream
- F25J2210/42—Nitrogen
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2210/00—Processes characterised by the type or other details of the feed stream
- F25J2210/50—Oxygen
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Separation By Low-Temperature Treatments (AREA)
Abstract
Air is separated in a cryogenic distillation system operating a dual reboiler/condenser cycle. Refrigeration for the system is usually provided by expanding a process stream. In the present invention, refrigeration is provided by introducing from an external source at least one refrigerant.
Description
Technical field
The present invention relates generally to air low temperature is separated into gaseous nitrogen (" GAN ") and gaseous oxygen (" GOX "), and, particularly relate to but might not only limit to the GOX of production low pressure and low-purity.
Background technology
For low-purity, for example 80 to 98vol%, low pressure, and for example the GOX of 1.5 to 5.0 crust absolute pressure (0.15 to 0.5MPa) has sizable market, especially in glass and metallurgical industry.GOX needing to be used for the technology of oxygen-enriched combusting, and the oxygen pressure that needs when wherein using is near atmospheric pressure.
Oxygen becomes vacuum suction method (" VSA ") and needing in the application of 90 to 93vol% oxygen to be generally used for.Yet, usually need can not provide so high purity economically by the VSA method up to the GOX of 98vol% oxygen.Cryogenic distillation method all is economical for the oxygen demand of low and higher degree.Formerly disclose and many air has been carried out the method that low temperature distillation is produced the GOX product.Many disclosed methods use the liquid refrigerant from external source to provide to the small part cooling load for this method.
US-A-5408831 (Guillard etc.) and US-A-5505052 (Ekins etc.) all disclose the single-stage reboiler/condensor circulation that is used to produce GOX, and what wherein this method was required is to be provided by at least a cold-producing medium from external source to the small part cooling load.For example, in the invention of Guillard etc., both use liquid oxygen (" LOX "), used liquid nitrogen (" LIN ") again; In the invention of Ekins etc., both used LOX, use liquid argon (" LAR ") again.Another kind of single-stage reboiler/condensor circulation is disclosed in US-A-2003/0110796.
US-A-6539748 (Prentice etc.) discloses in the single-stage reboiler/condensor round-robin method that is used for producing low pure GOX and has used the LOX from external source that refrigeration is provided.One LOX refrigerant stream from external source is injected in the main heat exchanger, and its pressure is higher than the pressure of LOX when Distallation systm enters main heat exchanger.In an exemplary embodiment, the vaporization that obtains the LOX cold-producing medium with the vaporization of taking from Distallation systm LOX mix the GOX product that obtains mixing.
Low pressure GOX can be produced by the secondary low temperature distillation Tower System that uses the circulation of secondary reboiler/condensor.The example of existing secondary reboiler/condensor round-robin method is disclosed in US-A-3210951 (Gaumer), US-A-4410343 (Ziemer) and US-A-4702757 (Kleinberg).Wherein every piece of document disclosed method is all by the processing medium swell refrigeration.
Fig. 1 has described an example of existing system.In air compressor 10, air is compressed generation compressed air stream 12, then it is purified the compressed air stream 16 that is purified in alternating temperature adsorption cleaning device 14.Then air stream 16 is divided into two parts.First 18 is further compression in compressor 20, then as the warm endfeed of logistics 21 to main heat exchanger 22, therein by the condensation with the LOX indirect heat exchange of vaporization, produces liquid air stream 24 (" LAIR ").Follow low pressure (" LP ") tower 26 chargings of LAIR, and be separated into the nitrogen and the LOX of cat head therein to Distallation systm.Shift out one LOX stream 28, make its cold junction that enters main heat exchanger 22,, obtain low pressure GOX stream 30 therein by vaporizing with the raw air indirect heat exchange.Make second portion 32 enter the warm end of main heat exchanger 22, cool off by LOX indirect heat exchange therein, produce the compression raw air stream 34 of cooling with vaporization.Remove one gaseous nitrogen (" GAN ") air-flow 35 from LP tower 26, and heating in main heat exchanger 22, useless GAN stream 37 produced.
The intermediate point of logistics 34 in main heat exchanger 22 punished into two parts, and first 36 is divided into two secondary logistics.First level logistics 38 enters high pressure (" the HP ") tower 40 of distillation column system, and this tower is under high pressure operated, and is separated into rich nitrogen overhead vapours and thick liquid oxygen (" CLOX ").Second subprime logistics 42 produces the air stream 46 of one partial condensation in first reboiler/condensor, 44 partial condensations of the hopper that is arranged in LP tower 26, then makes it enter the bottom of HP tower 40.
Rich nitrogen vapor stream of top of the tower 48 condensation with the vaporization CLOX heat exchange of shifting out in second reboiler/condensor 50 from HP tower 40 by logistics 52 from HP tower 40.The rich nitrogen overhead product of condensation enters the backflow that HP tower 40 separates with conduct in the LP tower 26 respectively as logistics 54 and 56.The CLOX of vaporization enters LP tower 26 by logistics 58.
Provide refrigeration by expansion turbine 60 for this method, the compressed-air actuated second portion 62 of cooling is introduced decompressor 60, and the acting of expanding there, produce expanded air stream 64, and be introduced into LP tower 26.Because decompressor is directly sent part middle pressure air into LP tower 26, just reduced the air stream that can enter the HP tower 40 and second reboiler/condensor 50.Inevitably, distillation is owing to the boiling of LOX in the hopper of LP tower 26 reduces and weakens along the minimizing of the backflow under the LP tower 26.
Use the example of secondary reboiler/condensor circulation of external refrigerant and expansion turbine refrigeration open in US-A-4668260 at the cryogenic air separation process that is used for producing high pure nitrogen.
The benefit of secondary reboiler/condensor circulation is that pressure-air is in the pressure lower than regular circulation, because the LOX in the LP tower 26 is vaporized by condensation air rather than nitrogen.This difference of air pressure causes power to reduce, unless be used to produce the air velocity increase of set GOX flow velocity.As if the result who weakens distillation is that air velocity increases, and therefore, the secondary reboiler/condensor circulation that has decompressor is compared with regular circulation, and its power advantage is very little, is not enough to offset extra complexity of this circulation and cost.The inventor does not find any instruction in the prior art, if promptly use external refrigerant to replace decompressor to satisfy the refrigeration requirement of this method, then the remarkable power advantage of secondary reboiler/condensor round-robin method can almost completely realize.
Summary of the invention
One of purpose of the preferred embodiment of the invention is the low pressure GOX for production low pressure GOX, especially low-purity, and providing a kind of needn't significantly increase the method and apparatus that any cost of investment just can reduce power consumption (and therefore reducing running cost).
According to a first aspect of the invention, provide a kind of in a low temperature distillation system method of low temperature air separating, this system comprises a high pressure (" HP ") destilling tower and a low-pressure distillation column (" LP "), one first reboiler/condensor, one second reboiler/condensor and heat-exchanger rig, described method comprises:
In the HP tower, raw air is separated into rich nitrogen overhead vapours and thick liquid oxygen (" CLOX ");
Described CLOX of at least a portion or consequent thick oxygen steam are separated in the LP tower, produce the overhead vapours and the liquid oxygen (" LOX ") of nitrogen;
By in described first reboiler/condensor with the LOX indirect heat exchange partial condensation air at least, produce the oxygen steam and the air of partial condensation at least;
By in described second reboiler/condensor with the oxygen enriched liquid indirect heat exchange the described rich nitrogen overhead vapours of partial condensation at least a portion at least, produce the oxygen-rich steam and the rich nitrogen overhead vapours of partial condensation at least;
By in described heat-exchanger rig, the LOX from described LP tower being vaporized, produce the compressed air of gaseous oxygen (" GOX ") and cooling with the compressed air indirect heat exchange; And
The air of the rich nitrogen overhead vapours of the described partial condensation at least of use at least a portion and/or the described partial condensation at least of at least a portion is as backflow in Distallation systm;
Wherein provide this method required cooling load by to Distallation systm, introducing at least a cold-producing medium from external source.This or at least a cold-producing medium are preferably selected from liquid nitrogen (" LIN ") or LOX.
An advantage of the invention is to provide refrigeration to this method by the expansion of processing medium.Use decompressor can cause tangible capital cost and running cost, and increase energy consumption.Do not need the expansion of processing medium just can satisfy the required overall refrigerating effect of this method, therefore, eliminated these unfavorable factors of cost and energy consumption aspect.Compare with the technology that has decompressor in the prior art, flow velocity and steam flow rate in the HP tower all increase.For given GOX flow velocity, compare with the air velocity in the conventional single-stage reboiler/condensor circulation, the increase of air velocity is zero substantially among the present invention.Therefore, use external cold-producing medium, provide the power advantage of the secondary reboiler/condensor circulation that the use decompressor of the secondary reboiler/condensor recycle ratio routine of refrigeration provides refrigeration big as LIN and/or LOX.Additional complexity and the cost of this power dominant foot to offset this circulation.
Can with should or every kind of cold-producing medium introducing device in any correct position in the low-temperature space.At this or at least a cold-producing medium is under the situation of LOX, can by make from the LOX of external source to the hopper charging of LP tower provide this method required to the small part cooling load.Perhaps, can by make LOX from external source in heat-exchanger rig with the vaporization of compressed air indirect heat exchange with the cooling agent of the compressed air that obtains cooling off and vaporization provide this method required to the small part cooling load.Also can be by providing to the small part cooling load in conjunction with carrying out this several steps.Under the situation that the LOX cold-producing medium is vaporized in the main heat exchange device, the GOX that obtains can with mix from the GOX that the LOX of LP tower obtains by vaporization, obtain mixing the GOX product.
At this or at least a cold-producing medium is under the situation of LIN, can be in the position of high nitrogen concentration introducing distillation column system from the LIN of external source.For example, can make the top that is fed into the LP tower from the LIN of external source, the top of the top of HP tower or these two towers.
LIN and LOX from external source can use simultaneously to provide this method required at least a portion cooling load.Yet, in preferred embodiments, only use a kind of cold-producing medium.
First reboiler/condensor is usually located in the hopper of LP tower.In such embodiments, this method comprise by with partial condensation air from the LOX indirect heat exchange of LP tower and at least, produce described oxygen steam and the described air of partial condensation at least.
Second reboiler/condensor can be arranged on the centre position of LP tower, in this case, this method comprise by with the rich nitrogen overhead vapours of partial condensation along the oxygen enriched liquid indirect heat exchange under the LP tower and at least, produce the rich nitrogen overhead vapours of described oxygen-rich steam and described partial condensation at least.Perhaps, second reboiler/condensor can be arranged on the outside of LP tower.In this case, this method comprise by with the rich nitrogen overhead vapours of partial condensation from the CLOX indirect heat exchange of HP tower and at least, produce the rich nitrogen overhead vapours of described thick oxygen steam and described partial condensation at least.
In the methods of the invention, not using processing medium to expand freezes.The advantage of these methods is that if do not expand gas-turbine in the system, the capital cost and the running cost of the circulation of secondary reboiler/condensor will reduce.
Raw air can comprise the compressed air of at least a portion cooling.Another selection or additionally be that raw air can comprise at least a portion air of partial condensation at least.Enter the compressed air that the raw air of HP tower preferably cools off, and make LAIR enter the LP tower.Yet in other embodiment, the compression raw air of all coolings partial condensation at least in first reboiler/condensor then enters the HP tower.And LAIR can enter the HP tower or distribute between HP tower and LP tower.
The backflow of LP tower and HP tower can be provided by any suitable liquid stream in the method.Especially, the rich nitrogen overhead vapours of HP tower and all available partial condensation at least of LP tower refluxes.
In preferred embodiments, the GOX of production low-purity is about 80 to 98vol.% as oxygen concentration, preferably the GOX of about 95vol.%.The pressure of GOX is preferably about 1.5 to about 5.0 crust absolute pressure (0.15 to 0.5MPa).Preferably, this pressure is about 1.7 to 2.3 crust absolute pressure (0.17 to 0.23MPa).The nitrogen overhead vapours can be removed from the HP tower, in main heat exchanger, be heated and collect as the GAN product.
According to a second aspect of the invention, provide a kind of equipment that is used for low temperature air separating, comprising:
A HP destilling tower that is used for raw air is separated into rich nitrogen overhead vapours and CLOX;
One flows with described HP tower fluid and to be connected and to be used for the described CLOX of at least a portion or consequent thick oxygen steam are separated LP destilling tower with generation nitrogen overhead vapours and LOX;
One be used for by with the LOX indirect heat exchange at least in part condensation air produce oxygen steam and first reboiler/condensor of the air of partial condensation at least;
One flows with described HP tower fluid and to be connected and to be used for by producing oxygen-rich steam and second reboiler/condensor of the rich nitrogen overhead vapours of partial condensation at least with the described rich nitrogen overhead vapours of oxygen enriched liquid indirect heat exchange condensation at least a portion at least in part;
Be connected and be used for producing the compressed-air actuated heat-exchanger rig of GOX and cooling from the LOX of LP tower with described LP tower fluid is mobile by vaporizing with the compressed air indirect heat exchange;
At least one flows with described HP tower and/or described LP tower fluid and is connected and is used for rich nitrogen overhead vapours with the air of the described partial condensation at least of at least a portion and/or the described partial condensation at least of at least a portion as the return duct device of backflow to the Distallation systm charging; With
At least one flows with described Distallation systm fluid and is connected and is used at least a cold-producing medium from the refrigerant pipe duct device of external source to described Distallation systm charging,
Wherein this equipment does not use the expansion gas-turbine that processing medium is expanded refrigeration is provided.
This equipment goes for and/or is configured to can be according to above-mentioned any method for optimizing operation.
Especially, be under the situation of LOX at this or at least a cold-producing medium, this or at least one refrigerant pipe duct device are used to transport LOX, and preferably are connected with the hopper fluid of LP tower is mobile.Additionally or as another select, this or at least a refrigerant pipe duct device can flow with the cold side fluid of heat transmission equipment and be connected.In this embodiment, this equipment also further comprises and is used for GOX that the vaporization from the LOX of LP tower is obtained and the GOX plumbing installation that the GOX that the LOX refrigerants vaporize obtains is mixed.
At this kind or at least a cold-producing medium is under the situation of LIN, should or at least a refrigerant pipe duct device be applicable to and transport LIN, and preferably with Distallation systm in have a high nitrogen concentration the position fluid flow and be connected.The suitable example of such position comprises the top of LP tower and the top of HP tower.
First reboiler/condensor is usually located in the hopper of LP tower.Second reboiler/condensor can be positioned at the middle part or the outside of LP tower.Under latter event, this device can further include and is used for thick oxygen steam from the plumbing installation of second reboiler/condensor to the charging of LP tower.
This equipment can comprise further that also the air that is used at least a portion partial condensation is as the plumbing installation of raw air to the charging of HP tower.As another selection or additionally, this equipment can comprise further that also the compressed air that is used at least a portion cooling is as the plumbing installation of raw air to the charging of HP tower.
Description of drawings
Below be the explanation of the preferred embodiment of the invention, as just example, and with reference to the accompanying drawings.In the accompanying drawings:
Fig. 1 is the flow chart that is used for the existing secondary reboiler/condensor round-robin method of production low-purity GOX;
Fig. 2 is that the present invention uses the flow chart of LOX as an embodiment of external refrigerant, and wherein second reboiler/condensor is positioned at the outside of LP tower;
Fig. 3 is that the present invention uses the flow chart of LOX as another embodiment of external refrigerant, and wherein second reboiler/condensor is positioned at the middle part of LP tower;
Fig. 4 is the flow chart of the use LOX shown in Fig. 2 as a kind of different structure of an embodiment of external refrigerant;
Fig. 5 is the flow chart of the use LIN shown in Fig. 2 as a kind of different structure of an embodiment of external refrigerant;
Fig. 6 is the flow chart of the use LIN shown in Fig. 5 as a kind of different structure of an embodiment of external refrigerant.
The specific embodiment
The represented method of Fig. 1 was above being discussed.
Flow chart shown in Fig. 2-6 and flow chart shown in Figure 1 have many common features.Used Reference numeral is used for representing same feature among Fig. 1 in Fig. 2 to 6.Part identical in the flow chart of Fig. 2 to 6 and the flow chart shown in Figure 1 was above being discussed in the discussion to Fig. 1.Hereinafter only limit to the difference in the method for the represented method of Fig. 1 and Fig. 2 to 6 expression is discussed.
In the flow chart that Fig. 2 represents, do not resemble among Fig. 1 expansion by processing medium refrigeration is provided.On the contrary, a small gangs of LOX is flowed the low-temperature zone of 66 introducing devices.LOX stream 66 by vaporizing with compressed air stream 32 and 21 indirect heat exchanges,, then mixes GOX stream 68 the GOX product stream 70 that obtains mixing to obtain GOX stream 68 with GOX stream 30 in main heat exchanger 22.Compressed air stream 36 is cooled to dew point, and flows 28 from the LOX that LP tower 26 shifts out by hydrostatic head or the compression of use pump (not shown).
In flow chart shown in Figure 3, second reboiler/condensor 50 is positioned at the centre position of LP tower 26, rather than is positioned at the outside of LP tower 26 resembling in the embodiment shown in Figure 2.Therefore, CLOX directly enters the LP tower as fluid 72.Not to resemble that the expansion by processing medium provides refrigeration Fig. 1.On the contrary, in Fig. 2, LOX is flowed the low-temperature zone of 66 introducing devices, LOX stream 66 by vaporizing with compressed air stream 32 and 21 indirect heat exchanges, obtains GOX stream 68 in main heat exchanger 22, then GOX stream 68 is mixed with GOX stream 30, obtains mixing the GOX product and flows 70.As shown in Figure 2, compressed air stream 36 is cooled to dew point, and flows 28 from the LOX that LP tower 26 shifts out by hydrostatic head or the compression of use pump (not shown).
In flow chart shown in Figure 4, will introduce in the hopper of LP towers 26 but not in the main heat exchanger 22, from the LOX of external source stream 66 for this method provides refrigeration.
In flow chart shown in Figure 5, will come to provide refrigeration from the top that the LIN stream 74 of external source is introduced HP tower 40, rather than in Fig. 2, will introduce in the main heat exchanger 22 from the LOX of external source for this method.
In flow chart shown in Figure 6, make LIN stream 74 come to provide refrigeration for this method from the top that external source enters LP tower 26.
Various external refrigerant as shown in Fig. 4 to 6 also can be used for the embodiment of method shown in Figure 3.
Embodiment
Having carried out computer simulation compares known single-stage reboiler/condensor circulation (S1-S4) and secondary reboiler/condensor circulation (D1-D3).Simulation is with 3500Nm
3/ h (containing) speed is produced 95vol%O
2The basis on carry out.The results are shown in the table 1.
| Circulation | ????S1 | ????S2 | ????S3 | ????S4 | ??D1 | ??D2 | ??D3 |
| Total condensation HP air stream in MHE | Do not carry out | Carry out | Carry out | Carry out | Carry out | Carry out | Carry out |
| Air transformer | Do not have | Have | Have | Have | Have | Have | Have |
| Decompressor | Do not have | Do not have | Have | Have | Do not have | Have | Have |
| Vacuum tank | Have | Have | Have | Do not have | Have | Have | Do not have |
| Condensation air in | Do not carry out | Do not carry out | Do not carry out | Do not carry out | Partial condensation * | Partial condensation * | Partial condensation * |
| O 2The rate of recovery | ????0.207 | ????0.208 | ????0.208 | ????0.207 | ??0.207 | ??0.205 | ??0.204 |
| MAC/ pressure regulator power (kW) | ????1423 | ????1397 | ????1464 | ????1441 | ??1244 | ??1326 | ??1344 |
| ％ | ????100 | ????98.2 | ????102.9 | ????101.3 | ??87.4 | ??93.2 | ??94.4 |
(
*Partial cond. represents partial condensation)
Table 1
Circulation S2 is a single reboiler circulation (that is, not having decompressor) of using outside LOX to freeze.Except using decompressor rather than outside LOX freeze, circulation S3 is identical with circulation S2.MAC/ pressure regulator power increases above 4%.
Circulation D2 is the secondary reboiler circulation of the use expander refrigeration of a routine.Among the MAC/ pressure regulator power ratio circulation S2 of this circulation low about 5%.Circulation D1 be one according to secondary reboiler of the present invention circulation (that is, using outside LOX rather than decompressor to freeze).Low about 11% among the MAC/ pressure regulator power ratio circulation S2 of this circulation is than low about 6% among the secondary reboiler circulation D2 of routine.
The result shows, compares with standard single-stage reboiler/condensor circulation (S1), uses the secondary reboiler/condensor circulation (D1) that has the LOX refrigeration to reduce by about 13% MAC/ pressure regulator power consumption.This reduction to power consumption is significant, because it has reduced the totle drilling cost that GOX produces significantly.The capital cost of estimation D2 and D3 method and the single-stage reboiler/condensor circulation S1's of standard is roughly the same.Yet the capital cost of estimating the D1 method is than lacking of S1 about 2%.Therefore, the preferred embodiments of the invention have not only reduced the production cost of GOX, have also reduced capital cost.
In whole specification, the term " device " in " realizing the device of certain function " this phrase means at least a device that is applicable to and/or is configured to realize this function.
Be understandable that the present invention is not limited in above with reference to the described details of preferred embodiment, in the spirit and scope of the present invention that claim limited that do not depart from subsequently, can also carry out multiple modification and variation.
Claims (34)
1. method of in low temperature distillation system, air being carried out cryogenic separation, this system comprises a high pressure (" HP ") destilling tower and a low pressure (" LP ") destilling tower, one first reboiler/condensor, one second reboiler/condensor and heat-exchanger rig, described method comprises:
Raw air in the HP tower is separated into rich nitrogen overhead vapours and thick liquid oxygen (" CLOX ");
Described CLOX of near small part or consequent thick oxygen steam separate in the LP tower, produce nitrogen overhead vapours and liquid oxygen (" LOX ");
By in described first reboiler/condensor, making air partial condensation at least, produce the oxygen steam and the air of partial condensation at least with the LOX indirect heat exchange;
By in described second reboiler/condensor, making the described rich nitrogen overhead vapours of at least a portion partial condensation at least, produce the oxygen-rich steam and the rich nitrogen overhead vapours of partial condensation at least with the oxygen enriched liquid indirect heat exchange;
By in described heat-exchanger rig, the LOX from the LP tower being vaporized, produce the compressed air of gaseous oxygen (" GOX ") and cooling with the compressed air indirect heat exchange; And
In Distallation systm, the rich nitrogen overhead vapours of the described partial condensation at least of use at least a portion and/or the air of the described partial condensation at least of at least a portion are as backflow;
Wherein, the required cooling load of this method provides by at least a cold-producing medium is introduced Distallation systm from external source.
2. method according to claim 1 wherein is somebody's turn to do or at least a cold-producing medium is selected from liquid nitrogen (" LIN ") or LOX.
3. method according to claim 1 wherein is somebody's turn to do or at least a cold-producing medium is LOX.
4. method according to claim 3, wherein the required at least a portion cooling load of this method is by providing from LOX charging in the hopper of LP tower of external source.
5. method according to claim 1, wherein the required at least a portion cooling load of this method is to carry out indirect heat exchange from the LOX of external source and compressed air and vaporize by making in heat-exchanger rig, and the LOX cold-producing medium of the compressed air of cooling and vaporization provides thereby produce.
6. method according to claim 5, also comprise with the LOX cold-producing medium of the described vaporization of at least a portion with mix the GOX product that obtains mixing by the described GOX that will obtain from the LOX vaporization of LP tower.
7. method according to claim 1 wherein is somebody's turn to do or at least a cold-producing medium is LIN.
8. method according to claim 7 wherein will be introduced Distallation systm from the LIN of external source in the position with high nitrogen concentration.
9. method according to claim 7 wherein will be introduced Distallation systm from the LIN of external source at the top of LP tower.
10. method according to claim 7 wherein will be introduced Distallation systm from the LIN of external source at the top of HP tower.
11. method according to claim 1, wherein first reboiler/condensor is arranged in the hopper of LP tower, described method comprise by with the LP tower in the LOX indirect heat exchange that produces and partial condensation air at least, produce the air of described oxygen steam and described partial condensation at least.
12. method according to claim 1, wherein second reboiler/condensor is arranged in the centre position of LP tower, described method comprise by with the LP tower in descending oxygen enriched liquid indirect heat exchange and the described rich nitrogen overhead vapours of partial condensation at least, produce the rich nitrogen overhead vapours of described oxygen-rich steam and described partial condensation at least.
13. method according to claim 1, wherein second reboiler/condensor is positioned at the outside of LP tower, described method comprise by with the HP tower in the CLOX indirect heat exchange that produces and the described rich nitrogen overhead vapours of partial condensation at least, produce the rich nitrogen overhead vapours of described thick oxygen steam and described partial condensation at least.
14. method according to claim 1, wherein said raw air comprises the compressed air of the described cooling of at least a portion.
15. method according to claim 1, wherein said raw air comprises the air of the described partial condensation at least of at least a portion.
16. method according to claim 1 is used to produce GOX.
17. method according to claim 1, wherein the GOX purity of Sheng Chaning is about 80-98vol%.
18. method according to claim 1, wherein the GOX pressure of Sheng Chaning is that about 0.15MPa is to about 0.5MPa.
19. method according to claim 1, wherein the expansion without processing medium provides refrigeration.
20. method according to claim 1 comprises the backflow as HP tower and/or LP tower of the air that uses partial condensation at least.
21. method according to claim 1 comprises the rich nitrogen overhead vapours that the uses condensation overhead reflux as the HP tower.
22. be used for air is carried out the equipment of cryogenic separation, comprise:
A HP destilling tower that is used for raw air is separated into rich nitrogen overhead vapours and CLOX;
A LP destilling tower that flows and to be connected and to be used for the described CLOX of at least a portion or consequent thick oxygen steam are separated generation nitrogen overhead vapours and LOX with described HP tower fluid;
One is used for by producing oxygen steam and first reboiler/condensor of the air of partial condensation at least with the LOX indirect heat exchange with condensation air at least in part;
One flows with described HP tower fluid and to be connected and to be used for by producing oxygen-rich steam and second reboiler/condensor of the rich nitrogen overhead vapours of partial condensation at least with the oxygen enriched liquid indirect heat exchange with the described rich nitrogen overhead vapours of condensation at least a portion at least in part;
Be connected and be used for producing the compressed-air actuated heat-exchanger rig of GOX and cooling from the LOX of LP tower with described LP tower fluid is mobile by vaporizing with the compressed air indirect heat exchange;
At least one flows with described HP tower and/or described LP tower fluid and is connected and is used for rich nitrogen overhead vapours with the air of the described partial condensation at least of at least a portion and/or the described partial condensation at least of at least a portion as the return duct device of backflow to the Distallation systm charging; With
At least one flows with described Distallation systm fluid and is connected and is used at least a cold-producing medium from the refrigerant pipe duct device of external source to described Distallation systm charging,
Wherein this equipment does not use the expansion gas-turbine that processing medium is expanded refrigeration is provided.
23. equipment according to claim 22 wherein is somebody's turn to do or at least one refrigerant pipe duct device is used to transport LOX, and is connected with the hopper fluid of LP tower is mobile.
24. equipment according to claim 22 wherein is somebody's turn to do or at least one refrigerant pipe duct device is used to transport LOX, and is connected with the cold side fluid of heat-exchanger rig is mobile.
25. equipment according to claim 24 also comprises the GOX plumbing installation that is used for vaporization produces from the LOX of LP tower described GOX is mixed with the GOX that makes described LOX refrigerants vaporize generation.
26. equipment according to claim 22, wherein should or at least one refrigerant pipe duct device be used to transport LIN, and with Distallation systm in have a high nitrogen concentration the position fluid flow and to be connected.
27. equipment according to claim 26 wherein is somebody's turn to do or at least one refrigerant pipe duct device is connected with LP top of tower fluid is mobile.
28. equipment according to claim 26 wherein is somebody's turn to do or at least one refrigerant pipe duct device is connected with HP top of tower fluid is mobile.
29. equipment according to claim 22, wherein first reboiler/condensor is arranged in the hopper of described LP tower.
30. equipment according to claim 22, wherein second reboiler/condensor is positioned at the centre position of described LP tower.
31. equipment according to claim 22, wherein second reboiler/condensor is positioned at the outside of described LP tower.
32. equipment according to claim 31 also comprises being used for thick oxygen steam from the plumbing installation of described second reboiler/condensor to the charging of described LP tower.
33. equipment according to claim 22 comprises that also the air that is used for the described partial condensation of at least a portion is as the plumbing installation of raw air to the charging of described HP tower.
34. equipment according to claim 22 comprises that also the compressed air that is used for the described cooling of at least a portion is as the plumbing installation of raw air to the charging of described HP tower.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP04251844A EP1582830A1 (en) | 2004-03-29 | 2004-03-29 | Process and apparatus for the cryogenic separation of air |
| EP04251844.9 | 2004-03-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1677040A true CN1677040A (en) | 2005-10-05 |
Family
ID=34878317
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200510068588.5A Pending CN1677040A (en) | 2004-03-29 | 2005-03-29 | Process and apparatus for the cryogenic separation of air |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US20050210916A1 (en) |
| EP (1) | EP1582830A1 (en) |
| CN (1) | CN1677040A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11815309B2 (en) * | 2018-11-07 | 2023-11-14 | L'Air Liquide, Société Anonyme pour l'Etude et l'Exploitation des Procédés Georges Claude | Integration of hydrogen liquefaction with gas processing units |
| US20230074304A1 (en) * | 2021-09-07 | 2023-03-09 | Uop Llc | Vapor distribution system in a concentric reboiler |
| CN113750797A (en) * | 2021-09-15 | 2021-12-07 | 黑龙江豪运药业有限公司 | Device and method for separating high-abundance isotope boron 11 boron trifluoride by low-temperature vacuum rectification boron trifluoride |
Family Cites Families (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3210951A (en) * | 1960-08-25 | 1965-10-12 | Air Prod & Chem | Method for low temperature separation of gaseous mixtures |
| US4410343A (en) * | 1981-12-24 | 1983-10-18 | Union Carbide Corporation | Air boiling process to produce low purity oxygen |
| GB2125949B (en) * | 1982-08-24 | 1985-09-11 | Air Prod & Chem | Plant for producing gaseous oxygen |
| JPS6124967A (en) * | 1984-07-13 | 1986-02-03 | 大同酸素株式会社 | Production unit for high-purity nitrogen gas |
| US4702757A (en) * | 1986-08-20 | 1987-10-27 | Air Products And Chemicals, Inc. | Dual air pressure cycle to produce low purity oxygen |
| US4842625A (en) * | 1988-04-29 | 1989-06-27 | Air Products And Chemicals, Inc. | Control method to maximize argon recovery from cryogenic air separation units |
| US5006137A (en) * | 1990-03-09 | 1991-04-09 | Air Products And Chemicals, Inc. | Nitrogen generator with dual reboiler/condensers in the low pressure distillation column |
| FR2699992B1 (en) * | 1992-12-30 | 1995-02-10 | Air Liquide | Process and installation for producing gaseous oxygen under pressure. |
| FR2706195B1 (en) * | 1993-06-07 | 1995-07-28 | Air Liquide | Method and unit for supplying pressurized gas to an installation consuming an air component. |
| JPH09184681A (en) * | 1995-11-02 | 1997-07-15 | Teisan Kk | Method for manufacturing super high-purity oxygen and nitrogen |
| US5761927A (en) * | 1997-04-29 | 1998-06-09 | Air Products And Chemicals, Inc. | Process to produce nitrogen using a double column and three reboiler/condensers |
| US6009723A (en) * | 1998-01-22 | 2000-01-04 | Air Products And Chemicals, Inc. | Elevated pressure air separation process with use of waste expansion for compression of a process stream |
| DE19815885A1 (en) * | 1998-04-08 | 1999-10-14 | Linde Ag | Air separation method producing gas, or gas and liquid e.g. for steel plant |
| EP1207362A1 (en) * | 2000-10-23 | 2002-05-22 | Air Products And Chemicals, Inc. | Process and apparatus for the production of low pressure gaseous oxygen |
| DE10161584A1 (en) * | 2001-12-14 | 2003-06-26 | Linde Ag | Device and method for generating gaseous oxygen under increased pressure |
-
2004
- 2004-03-29 EP EP04251844A patent/EP1582830A1/en not_active Ceased
-
2005
- 2005-03-18 US US11/083,451 patent/US20050210916A1/en not_active Abandoned
- 2005-03-29 CN CN200510068588.5A patent/CN1677040A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| US20050210916A1 (en) | 2005-09-29 |
| EP1582830A1 (en) | 2005-10-05 |
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