Device for separating air by cryogenic distillation

Abstract

A device for separating air by cryogenic distillation, comprising a first module containing a main air compressor, a second module, a third module containing a purification unit, a fourth module containing a heat exchanger and a system of columns comprising at least one distillation column that is or is not contained in the fifth module, the second module containing a connection for connecting the compressor of the first module to the purification unit of the third module in order to send compressed air from the compressor to the purification unit and also containing a connection for connecting the purification unit to the heat exchanger of the fourth module in order to send purified air in the purification unit to the heat exchanger.

Claims

1. A device for separating air by cryogenic distillation, the device comprising: a first module configured to contain a main air compressor, a third module having a total length, a fourth module containing a purification unit, a fifth module configured to contain a heat exchanger, and a system of columns comprising at least one distillation column, wherein the fifth module is connected to said at least one distillation column of the system of columns by at least two fluid connections such that the device is configured to send the air to be separated to the heat exchanger and to the at least one distillation column of the system of columns, and to allow at least one fluid separated in the system of columns to be heated within the heat exchanger, wherein the third module is a horizontally oriented structural module arranged on the ground and configured to provide direct structural support from an upper surface of the third module to a lower surface of the fourth module, such that the fourth module is positioned directly on top of and supported by the upper surface of the third module, wherein the third module defines a central piping connection zone along the total length of the third module, said central piping connection zone having a length corresponding to between one-fifth and two-thirds of the total length of the third module, said central piping connection zone being distinct from end portions of the third module, wherein the first module is fluidically connected via piping to interfaces located within said central piping connection zone of the third module to supply compressed air to the interfaces, wherein the fifth module is fluidically connected via piping through a sidewall of the third module to interfaces located within said central piping connection zone of the third module to exchange process fluids therewith, and wherein said at least one of the first module and the fifth module so connected is located facing said central piping connection zone of the third module, and, wherein at least one of said end portions of the third module, located outside said central piping connection zone, houses at least one non-cryogenic operational component selected from the group consisting of: an electrical cabinet, an instrumentation cabinet, a control cabinet, an analysis device, a regeneration gas heater, and combinations thereof.

2. The device as claimed in claim 1, wherein the third module contains an element that is a heat exchanger that is configured to cool the air coming from the first module destined for the fourth module.

3. The device as claimed in claim 1, wherein the third module contains an element that is an electrical cabinet.

4. The device as claimed in claim 1, wherein the third module contains an element that is an instrumentation/monitoring and control cabinet.

5. The device as claimed in claim 1, wherein the third module contains an element that is an analysis device.

6. The device as claimed in claim 1, wherein the third module contains an element that is a heat exchanger for heating a residual gas coming from a column and/or from the fifth module destined for the purification unit of the fourth module.

7. The device as claimed in claim 1, wherein the third module contains an element that is a heat exchanger for cooling the air downstream of a compression stage of an air compressor.

8. The device as claimed in claim 1, wherein the third module contains an element that is an air cooling heat exchanger connected to a cooling water circuit and optionally to a cooling water pump.

9. The device as claimed in claim 1, wherein the length of the central piping connection zone is between one fifth and two thirds of the total length of the third module.

10. The device as claimed in claim 9, wherein an element selected from the group consisting of a first heat exchanger configured to cool air from the first module, an electrical cabinet, analysis device, a second heat exchanger configured to heat a residual gas coming from a column and/or from the fifth module, a third heat exchanger configured to cool air downstream of a compression stage of an air compressor, an air cooling heat exchanger connected to a cooling water circuit, and combinations thereof, is arranged in the third module but outside the central part.

11. The device as claimed in claim 9, wherein an element, which is selected from the group consisting of a first heat exchanger configured to cool air from the first module, an electrical cabinet, analysis device, a second heat exchanger configured to heat a residual gas coming from a column and/or from the fifth module, a third heat exchanger configured to cool air downstream of a compression stage of an air compressor, an air cooling heat exchanger connected to a cooling water circuit, and combinations thereof, is arranged in the third module but outside the central part at a first end of the third module and at least a second element, which is selected from the group consisting of the first heat exchanger configured to cool air from the first module, an electrical cabinet, analysis device, the second heat exchanger configured to heat the residual gas coming from the column and/or from the fifth module, the third heat exchanger configured to cool air downstream of the compression stage of an air compressor, an air cooling heat exchanger connected to the cooling water circuit, and combinations thereof, is arranged in the third module but outside the central part at the second end of the third module.

12. The device as claimed in claim 1, wherein the fourth module has a central part comprising between one fifth and two thirds of a total length of the fourth module, two adsorbent recipients being arranged on either side of the central part.

13. The device as claimed in claim 1, wherein the third and/or the fourth module has the dimensions of a standardized container in accordance with ISO 668 standards.

14. The device as claimed in claim 1, wherein for the third and/or fourth module, the ratio between the length of the module and its width is greater than three.

15. The device as claimed in claim 1, wherein for the third and/or fourth module, the ratio between the length of the module and its height is greater than three.

16. The device as claimed in claim 1, further comprising a second module containing a booster air compressor.

17. The device as claimed in claim 1, wherein the third module does not provide load-bearing support for any modules other than the fourth module.

18. The device as claimed in claim 1, wherein the third module has an inner volume in which both the central piping zone and the at least one non-cryogenic operational component are disposed.

19. A device for separating air by cryogenic distillation, the device comprising: a first module configured to contain a main air compressor; a third module having a total length; a fourth module containing a purification unit wherein the purification unit comprises a first adsorbent container and a second adsorbent container; a fifth module configured to contain a heat exchanger; and a system of columns comprising at least one distillation column, wherein the third module comprises fluid transport means that are configured to fluidly connect the other modules together, wherein the fifth module is connected to said at least one distillation column of the system of columns by at least two fluid connections such that the device is configured to send the air to be separated to the heat exchanger and to the at least one distillation column of the system of columns, and to allow at least one fluid separated in the system of columns to be heated within the heat exchanger, wherein the third module is arranged on the ground and provides structural support for the fourth module, wherein the third module has a central part corresponding to between two thirds and one fifth of its length, wherein the first and the fifth module is connected to this central part and located facing this central part, wherein the first adsorbent container is disposed at a first horizontal end of the fourth module and the second adsorbent container is disposed at a second horizontal end of the fourth module, such that the first adsorbent container and the second adsorbent container are located outside a central section of the fourth module, wherein a majority of valves of the purification unit are disposed in the central section of the fourth module between the first and second adsorbent containers, wherein the central section of the fourth module is located above the central part of the third module, wherein the fifth module is fluidically connected via piping through a sidewall of the third module to interfaces located within said central piping connection zone of the third module to exchange process fluids therewith.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further features, advantages and possible applications of the invention are apparent from the following description of working and numerical examples and from the drawings. All described and/or depicted features on their own or in any desired combination form the subject matter of the invention, irrespective of the way in which they are combined in the claims or the way in which said claims refer back to one another.

(2) FIG. 1, FIG. 2 and FIG. 3 show devices according to certain embodiments of the invention.

(3) FIG. 1 illustrates a side view of device according to certain embodiments of the invention.

(4) FIG. 2 illustrates a top view of the same device.

(5) FIG. 3 illustrates a cross-section of two modules of certain embodiments of the device along their main axis.

DETAILED DESCRIPTION OF THE INVENTION

(6) As can be seen in FIG. 1, the device comprises six modules preferably arranged on the ground S, with the exception of the fourth module 4. The first module 1 contains a main air compressor (MACFIG. 2) for compressing all of the air for distillation. The second module 2 is optional and contains a booster air compressor (BACFIG. 2). The fourth module 4 contains an air purification unit (CFIG. 3) for purifying the air for distillation into water and into carbon dioxide and secondary impurities of air, in particular two adsorbent recipients at the ends of the module separated by piping and regulating valves. The third module 3 contains at least means making it possible to connect other modules to each other. The fifth module contains a heat exchanger (HXFIG. 2) at least the cold end of which is designed to operate at a temperature below 50 C., or even at a cryogenic temperature, and a distillation column (COLFIG. 2). The sixth module 6, which is optional, contains a refrigeration unit (60FIG. 2) for cooling the compressed air upstream of the purification unit, directly or via a chilled water circuit.

(7) The third module 3 and the fourth module 4 are arranged one on top of the other with the fourth module above the third module, so that the third module supports the fourth module and is arranged on the ground S.

(8) The third and fourth modules are preferably the same length and the same width, so that the two modules 3, 4 form a block that is the same length as each module 3, 4 and the same width as each module 3, 4. The modules 3, 4 are not necessarily identical in height.

(9) Each of the third and fourth modules comprises an enclosure in the form of a right rectangular prism, or even a right square prism. At least one of the third and fourth modules can be a standardized container. Otherwise, the framework of the third and/or of the fourth module can have the dimensions of a standardized container and be provided with standardized handling systems in the corners, for example standardized corners, for example in accordance with ISO 668. Otherwise, the framework of the third and/or of the fourth module can have dimensions that allow it to fit into a standardized container.

(10) Preferably for the third and/or fourth module, the ratio between the length of the module and its width is greater than three and the ratio between the length of the module and its height is greater than three.

(11) The third and fourth modules 3, 4 are arranged with their length extending horizontally and are in the form of a right cuboid.

(12) The fourth module 4 comprises one or more enclosures containing a purification unit and preferably does not comprise a compressor.

(13) The fourth module 4 is connected to the first module 1 through the third module, the means for transporting the air from the compressor of the first module to the purification unit passing through the third module 3 before arriving at the purification unit.

(14) The fourth module 4 is also connected to the heat exchanger of the fifth module 5, the means for transporting the air purified in the purification unit of the fourth module passing through the third module 3 before arriving at the heat exchanger of the fifth module.

(15) The fifth module 5 comprises an enclosure in the form of a right rectangular prism, or even a right square prism. The enclosure is preferably a standardized container or an identical size to a standardized container, and is provided with standardized handling systems in the corners. Alternatively, the fifth module comprises a cylindrical enclosure.

(16) The fifth module 5 is arranged with its length extending vertically. It contains a distillation column preferably arranged above the heat exchanger. The hot end of the heat exchanger is preferably positioned low down. The distillation column produces at least one fluid rich in a component of air that is heated in the exchanger and is then sent to the third module 3 to be sent into the atmosphere or to a client from this third module 3.

(17) The base of the fifth module is facing the third module in order to facilitate this transfer.

(18) The fifth module 5 can contain an air expansion turbine for supplying cold energy of the method but other means for keeping cold can be envisaged, for example liquid nitrogen feeding. It can also comprise at least one heat exchanger for supercooling the air destined for the column or a liquid coming from the distillation system. The fifth module will be insulated in order to allow the elements that it contains to operate at below-ambient or even cryogenic temperatures, preferably by means of vacuum insulation.

(19) The air compressed in the first module can optionally be sent to a refrigeration unit in a sixth module 6, the air passing from the first to the sixth module through the third module 3.

(20) As a result, it is recommended that the first module 1 be arranged facing the sixth module 6 in order to make the device more compact.

(21) Alternatively, chilled water can be sent from a refrigeration unit in a sixth module 6 to the third module 3 in order to cool the air in an exchanger.

(22) The air cooled directly or indirectly by the refrigeration unit is then sent to the fourth module, passing through the third module.

(23) The device can optionally comprise a booster compressor in a second module 2.

(24) The air compressed in the first module and purified in the fourth module can be sent to a booster compressor in the second module 2, the purified air passing from the fourth to the second module through the third module 3.

(25) The air compressed in the second module is then sent to the fifth module 5 to be cooled, passing through the third module 3.

(26) It will be easily understood that there can be a plurality of second modules containing booster compressors, or the second module can contain a plurality of booster compressors.

(27) As all of the fluids passing through the third module are at least at ambient temperature, it is not necessary to insulate the third module 3 by filling the module with loose-fill insulation. However, it is desirable to insulate certain elements of the third module 3 by cladding them with insulation. For example, the air cooled by the refrigeration unit of the module 6 must circulate in a pipe clad with a layer of insulation in order to limit heating. Likewise, the heater of the third module is insulated in order to protect personnel and limit heat losses.

(28) The third module 3 does not contain a distillation column and preferably does not contain any compressors. It can contain: A heat exchanger, for example for cooling the air coming from the first module destined for the fourth module, and/or An electrical cabinet, and/or An instrumentation/monitoring and control cabinet, and/or An analysis device, and/or A heat exchanger for heating a residual gas coming from a column and/or from the fifth module destined for the purification unit of the fourth module, and/or A heat exchanger for cooling the air downstream of a compression stage of an air compressor, and/or An air cooling heat exchanger connected to a cooling water circuit.

(29) The third module preferably does not contain any elements operating at cryogenic temperatures, or even at temperatures below 0 C.

(30) A residual gas produced by distillation must be sent to the purification unit for the regeneration of the purification unit. This flow will be heated, preferably in the heat exchanger of the third module, and sent to the fourth module where it can be heated again by a dedicated heat exchanger present in the fourth module.

(31) The walls of the third and/or of the fourth module 3, 4 can be clad with metal sheets or otherwise can be virtual walls.

(32) The connections between the third and fourth modules 3, 4 pass through the roof or top or the base or bottom of the third module (here the roof or top, as the third module is below the fourth module). These connections are thus made inside the common block formed by the two modules.

(33) The connections to the first module and to the fifth module will be made in side walls of the third module.

(34) The fourth module 4 is a framework, which can be enclosed by metal sheeting, containing at least one, or even at least two purification recipients, for example a cylinder. One recipient is preferably arranged at one end of the fourth module and another at the other end of the fourth module. Between the two recipients are the pipes connecting the recipients to each other, to the air inlet and to the purified air outlet, and to the regeneration gas.

(35) The fourth module 4 does not contain a distillation column and preferably does not contain any compressors.

(36) The third and fourth modules each comprise a top or roof, a bottom or base and four side walls. For the fourth module, the connection to the third module passes through the roof or top of the third module and the base or bottom of the fourth module. If the framework is not clad with metal sheets, the walls, roof and base are represented by the sides of the framework.

(37) For the third module comprising a roof, a base and four side walls, the at least two connections to the fifth module pass through a side wall.

(38) The at least two connections from the third module to the fifth module 5 pass through a side wall facing the side wall through which the connection to the second module 2 passes.

(39) The first module 1 is arranged beside the stacked third and fourth modules 3, 4. A second module 2 can also be arranged on the same side of the stacked modules 3, 4 as the first module 1.

(40) The fifth module 5 is preferably located on the other side of the stacked third and fourth modules 3, 4 from the first and optionally second modules 1, 2.

(41) The sixth module 6, if present, is preferably arranged on the same side as the fifth module 5.

(42) The device can comprise at least one distillation column outside the fifth module 5 and the fifth module 5 can contain no distillation columns.

(43) The main axis of the first, second or sixth module 1, 2, 6 is perpendicular to the common main axis of the third and fourth modules 3, 4.

(44) At least one of the first, second, third, fourth and fifth modules 1, 2, 3, 4, 5 comprises a framework, optionally at least partially enclosed.

(45) The third and fourth modules can be placed or fastened on the third module in order to form an element for transporting, and this element has the dimensions of a standardized container or can fit inside a standardized container.

(46) Each of the modules can be mounted on a skid to facilitate the transportation thereof. The height of a module does not exceed 3 m, or even 2 m, for this reason.

(47) The third module 3 is a piping module for the device for separating air by cryogenic distillation, making it possible to connect an air compressor 1, 2, a purification unit 4, and a heat exchanger 5.

(48) The compressor 1, the purification unit 4 and the heat exchanger 5 are connected to each other and the exchanger is connected to a system of columns for separating air.

(49) It comprises a first compressed air coupling in a first wall on the main compressor side capable of being coupled to a fluid pipe coming from the main compressor, two auxiliary couplings in a second wall on the purification unit side, including a first auxiliary coupling capable of being coupled to a fluid pipe destined for the purification unit and a second auxiliary coupling capable of being coupled to a pipe for fluid purified in the purification unit, and at least one additional coupling in a third wall on the heat exchanger side capable of being coupled to the heat exchanger 5. The first coupling is connected to the first auxiliary coupling by means arranged in the module and the second auxiliary coupling is connected to an additional coupling by means arranged in the module. The compressor, the heat exchanger and the purification unit are thus grouped around the module 3. One of the three elements can be arranged on the third module 3 with the other two placed on the ground like the third module.

(50) The module 3 comprises at least two couplings on the heat exchanger side, including one capable of being coupled to a pipe for purified fluid destined for the heat exchanger and at least one capable of being coupled to a pipe for fluid heated in the heat exchanger.

(51) Preferably, the first wall is facing the third wall and the second wall is perpendicular to the first and third walls. The second wall can form a roof of the module 3 or an end of the module 3.

(52) If the exchanger comprises n exchange bodies, the module comprises at least 2n couplings on the heat exchanger side.

(53) If the purification unit comprises n adsorbent recipients and at least 2n auxiliary couplings in a second wall on the purification unit side, including at least n first auxiliary couplings capable of being coupled to a fluid pipe destined for the purification unit and at least n second auxiliary couplings capable of being coupled to a pipe for fluid purified in the purification unit.

(54) The first, second and third walls each have two edges formed by the length of the module 3.

(55) In this example, the first, second, third, fifth, and sixth modules are arranged on the ground. As explained above, it is possible that at least one of these modules be arranged on intermediate means placed on the ground for reasons of stability and to facilitate the civil engineering.

(56) The first and optionally the second module cannot be located at a level above the highest of the third and fourth modules as one aim of the invention is to reduce the length of the connections and/or to reduce the footprint of the device as a whole.

(57) The invention aims to reduce the distance between the first module and the block formed by the third and fourth modules and/or the distance between the fifth module and the block formed by the third and fourth modules.

(58) In the example, the fourth module is arranged on the ground and acts as a support for the third module, but as a variant the third module is arranged on the ground and acts as a support for the fourth module.

(59) As each of the first and fifth modules must be connected to the third module, the decision to position the fourth module on the ground or on the third module itself positioned on the ground depends on the dimensions of the first (or fifth) module. For example, if the first module is relatively low, it will be connected to the fourth module placed on the ground, and if the first module is relatively high, it will be connected to the fourth module placed on the third module, itself arranged on the ground.

(60) FIG. 3 illustrates the arrangement of the elements in the third and fourth modules. The fourth module 4 placed on the third module comprises two adsorbent recipients C placed on either side of a central part T occupied by the piping and the regulating valves of the purification unit. At least some, preferably at least most, of the valves of the purification unit are arranged in the central part of the fourth module. At least most of the valves of the purification unit are arranged between the two recipients of the fourth module. The central part T of the fourth module 4 is located above the central part W of the third module in order to facilitate the connections between the compressor and the heat exchanger of the cold box and reduce the pressure drops.

(61) This piping and these valves are connected to the recipients C and, through the base of the fourth module and the roof of the third, pass through the third module to the first and fifth modules, for example. The connecting piping is located in the central part W of the third module 3. At one end of the third module is at least one element X, which can be: A heat exchanger, for example for cooling the air coming from the first module destined for the fourth module, and/or An electrical cabinet, and/or An instrumentation/monitoring and control cabinet, and/or An analysis device, and/or A heat exchanger for heating a residual gas coming from a column and/or from the fifth module destined for the purification unit of the fourth module, and/or A heat exchanger for cooling the air downstream of a compression stage of an air compressor, and/or An air cooling heat exchanger connected to a cooling water circuit. At the other end of the third module is at least one element Y A heat exchanger, for example for cooling the air coming from the first module destined for the fourth module, and/or An electrical cabinet, and/or An instrumentation/monitoring and control cabinet, and/or An analysis device, and/or A heat exchanger for heating a residual gas coming from a column and/or from the fifth module destined for the purification unit of the fourth module, and/or A heat exchanger for cooling the air downstream of a compression stage of an air compressor, and/or An air cooling heat exchanger connected to a cooling water circuit, and/or A cooling water pump of the cooling water circuit.

(62) Although it is possible to duplicate a particular element, the element(s) X at one end will not be the same as the element(s) Y at the other end.

(63) For example, an air cooling heat exchanger connected to a cooling water circuit can be arranged at one end, perhaps with at least one water pump, and an element other than an air cooling heat exchanger connected to a cooling water circuit can be arranged at the other end, for example a heat exchanger for heating a residual gas coming from a column and/or from the fifth module, destined for the purification unit of the fourth module.

(64) The proposed modules thus make it possible to arrange a large number of elements connected to the purification unit while reducing the footprint. Access for users is facilitated, as the elements that must be easy to access are at ground level.

(65) For the third and/or fourth modules 3, 4, the ratio between the length of the module and its width is greater than three, and/or the ratio between the length of the module and its height is greater than three.

(66) While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. The present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. Furthermore, if there is language referring to order, such as first and second, it should be understood in an exemplary sense and not in a limiting sense. For example, it can be recognized by those skilled in the art that certain steps can be combined into a single step.

(67) The singular forms a, an and the include plural referents, unless the context clearly dictates otherwise.

(68) Comprising in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing (i.e., anything else may be additionally included and remain within the scope of comprising). Comprising as used herein may be replaced by the more limited transitional terms consisting essentially of and consisting of unless otherwise indicated herein.

(69) Providing in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actor in the absence of express language in the claim to the contrary.

(70) Optional or optionally means that the subsequently described event or circumstances may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.

(71) Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.

(72) All references identified herein are each hereby incorporated by reference into this application in their entireties, as well as for the specific information for which each is cited.