Reducer, top reducer, air separator

Abstract

The present invention provides a modular reducer that has a simple structure and can be made compact in size. [Solution] The heat exchanger comprises a heat exchanger block 1, a steam supply header 3, a residual steam header 4, and a liquid reservoir 2. The heat exchanger block 1 is a plate fin type heat exchanger block 1 in which evaporation passages 8 and condensation distillation passages 9 are stacked. The steam supply header 3 is provided on the bottom surface of the heat exchanger block 1. The residual steam header 4 is provided on the top surface of the heat exchanger block 1. The liquid reservoir 2 is provided on at least one side surface in the width direction x perpendicular to the stacking direction z of the heat exchanger block 1, so as to define the internal space by this side surface and the inner circumferential surface of the liquid reservoir 2. The liquid reservoir 2 has a liquid supply port 6 for introducing liquid from the outside into the internal space, a steam outlet 5 for taking out steam from the internal space, and a liquid outlet 7 for taking out the liquid stored in the internal space.

Description

[[Technical Field]]

[0001] The present invention relates to a partial condenser that has a simple structure and can be reduced in size, as well as a top partial condenser and an air separation device using the same. [[Background Art]]

[0002] A partial condenser is used as a separation device or a condenser for partially condensing vapor. A plate-fin heat exchanger in which an evaporation passage and a condensing distillation passage are formed by plates and fins is applied to such a partial condenser.

[0003] In a partial condenser, a liquid is supplied as a refrigerant to the evaporation passage, and multi-component vapor is introduced from the bottom into the condensing distillation passage. The vapor introduced into the condensing distillation passage is partially liquefied by heat exchange with the refrigerant in the evaporation passage, and mass transfer is performed through countercurrent contact between the vapor and the liquid. Therefore, the vapor rises while concentrating low-boiling-point components, and the generated liquid descends while concentrating high-boiling-point components.

[0004] Conventionally, as the partial condenser as described above, for example, a partial condenser formed of a heat exchanger block including an evaporation passage and a condensing distillation passage is known (see, for example, Patent Documents 1 and 2). For example, Patent Document 1 discloses a partial condenser including, as the partial condenser, a heat exchanger block formed of an evaporation passage and a condensing distillation passage, and a pressure vessel surrounding the upper side and the entire outer peripheral side of the heat exchanger block. The pressure vessel serves as a vessel for storing the liquid that immerses the heat exchanger block and flows into the evaporation passage.

[0005] Further, for example, Patent Document 2 discloses a partial condenser, which is also referred to as a "dephlegmator" in Patent Document 2, including a heat exchanger block formed of an evaporation passage and a condensing distillation passage, and a gas-liquid separator for storing a refrigerant to be supplied to the heat exchanger block. [[Prior Art Literature]] [[Patent Documents]]

[0006] [Patent Document 1] Patent No. 7308237 [Patent Document 2] Japanese Patent Application Publication No. 11-244603 [Overview of the project] [Problems that the invention aims to solve]

[0007] The condenser described in Patent Document 1 utilizes the space between the heat exchanger block and the pressure vessel (hereinafter also simply referred to as "vessel") as a refrigerant flow storage space. For this reason, the condenser described in Patent Document 1 has openings on both sides of the lower part of the heat exchanger block and on both sides of the upper part of the heat exchanger block, making it possible to operate the refrigerant passages of the heat exchanger block in the form of a circulating evaporator by the thermal siphon effect.

[0008] However, the heat exchanger described in Patent Document 1 required a large container that could surround the heat exchanger block from above and all sides, resulting in the problem of the entire heat exchanger being large. In addition, the container surrounding the heat exchanger block required various modifications, such as passing pipes through it to extract steam from the heat exchanger block, which resulted in the container's structure becoming complex.

[0009] Furthermore, the heat exchanger described in Patent Document 2 also had the problem of requiring a gas-liquid separator and piping for supplying refrigerant from the gas-liquid separator to the heat exchanger block on the outside of the heat exchanger block, which resulted in the entire heat exchanger being made larger.

[0010] Therefore, the present invention aims to provide a condenser with a simple structure and a compact size, a tower top condenser using the same, and an air separation device. [Means for solving the problem]

[0011] To achieve the above objective, the present invention provides the following means. [1] A heat exchanger block having an evaporation passage through which a liquid to be evaporated flows, and a condensation distillation passage through which vapor for condensation distillation, which exchanges heat with the liquid flowing through the evaporation passage, A steam supply header for supplying the steam to the condensation distillation passage, A residual vapor header for extracting the residual vapor distilled in the aforementioned condensation distillation passage, It comprises a liquid reservoir having an internal space for storing the liquid supplied to the evaporation passage and the liquid that has flowed out of the evaporation passage, The heat exchanger block is a plate-fin type heat exchanger block in which the evaporation passages and condensation distillation passages, which consist of plates and fins, are alternately stacked. The steam supply header is provided on the bottom surface of the heat exchanger block, The residual steam header is provided on the top surface of the heat exchanger block, The liquid reservoir is provided on at least one side surface in the width direction perpendicular to the stacking direction of the heat exchanger block, covering both an opening for supplying liquid to the evaporation passage provided on that side surface and an opening for discharging the gas-liquid two-phase flow from the evaporation passage, and the internal space is defined by the side surface and the inner circumferential surface of the liquid reservoir. The liquid reservoir is characterized by having a liquid supply port for introducing liquid from the outside into the internal space, a steam outlet for removing steam from the internal space, and a liquid outlet for removing the liquid stored in the internal space. [2] The heat exchanger block is provided with one side and the other side in the width direction, respectively, and is provided with a connecting pipe for circulating the liquid in the two liquid reservoirs provided on the one side and the other side, as described in [1]. [3] A top condenser provided at the top of a distillation column, comprising: a condenser according to [1] or [2]; an introduction section having a communication section that connects the vapor supply header of the condenser to the top of the distillation column; and a liquid collector for collecting the liquid flowing down through the condensation distillation passage to the introduction section. [4] An air separation device comprising a double rectification system for extracting nitrogen, oxygen and argon from air, wherein the overhead partial condenser according to [3] is provided as an overhead partial condenser of an argon column. [Effects of the Invention]

[0012] According to the present invention, there can be provided a partial condenser having a simple structure and capable of being reduced in size, an overhead partial condenser using the same, and an air separation device. In particular, in the partial condenser of the present invention, since the liquid reservoir provided on the side surface of the heat exchanger block serves as a liquid reservoir container for a coolant, a compact and simple structure in which the heat exchanger block and the liquid reservoir container are integrated is achieved. [Brief Description of Drawings]

[0013] [Figure 1] It is a partially see-through perspective view that schematically shows a schematic configuration of the partial condenser according to the first embodiment of the present invention. [Figure 2] It is a plan view that schematically shows the partial condenser shown in FIG. 1. [Figure 3] It is an explanatory diagram for explaining the configuration of an evaporation passage in the partial condenser shown in FIG. 1. [Figure 4] It is an explanatory diagram for explaining the configuration of a condensing distillation passage in the partial condenser shown in FIG. 1. [Figure 5] It is a plan view that schematically shows the partial condenser according to the second embodiment of the present invention. [Figure 6] It is a plan view that schematically shows the overhead partial condenser according to the third embodiment of the present invention. [Figure 7] It is a diagram that schematically explains the air separation device according to the fourth embodiment of the present invention, and is a system diagram showing a schematic configuration of the entire air separation device. [Figure 8] It is a diagram that schematically explains an air separation device using a conventional partial condenser as an overhead partial condenser of an argon column, and is a system diagram showing a schematic configuration of a part of the air separation device. [Mode for Carrying Out the Invention]

[0014] Hereinafter, the present invention will be described based on preferred embodiments.

[0015] <First Embodiment> Figure 1 is a partially see-through perspective view schematically showing the schematic configuration of the fractionating condenser according to the first embodiment, and Figure 2 is a plan view schematically showing the fractionating condenser shown in Figure 1. As shown in Figure 1 and Figure 2, the fractionating condenser 10A of the present embodiment is a fractionating condenser 10A including a heat exchanger block 1, a vapor supply header 3, a residual vapor header 4, and a liquid reservoir 2.

[0016] The heat exchanger block 1 has an evaporation passage 8 through which an evaporating liquid flows, and a condensing distillation passage 9 through which vapor for condensing distillation by exchanging heat with the liquid flowing through the evaporation passage 8 flows. The vapor supply header 3 is for supplying vapor to the condensing distillation passage 9. The residual vapor header 4 is for taking out residual vapor distilled in the condensing distillation passage 9. The liquid reservoir 2 is for storing the liquid supplied to the evaporation passage 8 and the liquid flowing out from the evaporation passage 8.

[0017] In the fractionating condenser 10A of the present embodiment, the evaporating liquid flowing through the evaporation passage 8 receives heat from the vapor flowing through the condensing distillation passage 9, and a part thereof evaporates. The liquid flowing through such an evaporation passage 8 functions as a refrigerant in the fractionating condenser 10A. The "evaporating liquid" flowing through the evaporation passage 8 may be referred to as "liquid as a refrigerant" or simply "refrigerant". In the fractionating condenser 10A of the present embodiment, the liquid reservoir 2 for storing the liquid as a refrigerant is directly provided to the heat exchanger block 1, and a compact and simple structure in which the heat exchanger block 1 and the liquid reservoir container for storing the refrigerant are integrated is realized.

[0018] The following describes each component in detail. In Figures 1 and 2, the arrows labeled V and L indicate the direction of fluid flow. The V attached to the arrow indicates that the fluid is vapor. The L attached to the arrow indicates that the fluid is liquid. The W attached to V and L indicates that the fluid is warm. The c attached to V and L indicates that the fluid is cold. When attached to w or c, i indicates that the fluid is coming in, and o indicates that the fluid is going out.

[0019] In Figure 1, the arrow denoted by z indicates the direction in which the evaporation passages 8 and condensation / distillation passages 9, consisting of plates and fins, are alternately stacked in the heat exchanger block 1. The direction indicated by the arrow denoted by z is called the stacking direction z. The arrow denoted by y indicates the vertical direction (up and down direction) defined by the bottom and top surfaces of the heat exchanger block 1. Here, the vertical direction of the heat exchanger block 1 is the direction parallel to the main steam flow direction in the condensation / distillation passages. The direction indicated by the arrow denoted by y is called the vertical direction y. In the condenser 10A of this embodiment, the stacking direction z and the vertical direction y are orthogonal. The arrow denoted by x indicates a direction orthogonal to both the vertical direction y and the stacking direction z. The direction indicated by the arrow denoted by x is called the width direction x of the heat exchanger block 1. The width direction x of the heat exchanger block 1 is sometimes simply referred to as "width direction x".

[0020] <Heat exchanger block> The heat exchanger block 1 is composed of plates and fins and has an evaporation passage 8 through which a liquid refrigerant flows, and a condensation distillation passage 9 through which vapor flows for condensation distillation by exchanging heat with the refrigerant flowing through the evaporation passage 8. The heat exchanger block 1 is a plate-fin type heat exchanger block.

[0021] As shown in Figures 1 and 2, the evaporation passage 8 is provided extending from the lower to the upper part of the heat exchanger block 1. On the lower side of the evaporation passage 8, as shown in Figure 3, a liquid introduction passage 15 is provided for introducing the liquid (refrigerant) from the liquid reservoir 2, and a liquid introduction opening 15a is provided at the inlet of the liquid introduction passage 15. Here, Figure 3 is an explanatory diagram illustrating the configuration of the evaporation passage 8 in the condenser 10A shown in Figure 1.

[0022] Furthermore, a gas-liquid two-phase fluid outlet passage 17 is provided on the upper side of the evaporation passage 8 for discharging the gas-liquid two-phase fluid, and a gas-liquid two-phase flow opening 17a is provided at the outlet of the gas-liquid two-phase fluid outlet passage 17. Here, although the details will be described later, the gas-liquid two-phase fluid is a fluid that contains vapor obtained when the liquid introduced into the evaporation passage 8 receives heat from the fluid flowing through the condensation distillation passage 9, and a portion of it evaporates.

[0023] The liquid inlet passage 15 and the gas-liquid two-phase fluid outlet passage 17 of the evaporation passage 8 are formed by orienting fins laterally, as shown in Figure 3. Note that the direction of the lines indicated on the evaporation passage 8 in Figure 3 represents the orientation of the fins provided in the evaporation passage 8.

[0024] As shown in Figures 1 and 2, the condensing distillation passage 9 is provided extending from the lower end to the upper end of the heat exchanger block 1. As shown in Figure 4, the lower end of the condensing distillation passage 9 is a steam introduction opening 9a for introducing steam, and the upper end is a residual steam opening 9b for dischargering residual steam. Here, the condensing distillation passage 9 shown in Figure 4 has a convergence passage 39 at the top of the condensing distillation passage 9 for concentrating the condensing distillation passage 9 to the center in the width direction x, and a central passage 41 communicating with the convergence passage 39. However, the condensing distillation passage 9 does not necessarily have such a convergence passage 39 and a central passage 41. If there is no convergence passage 39 and a central passage 41, although not shown in the figure, the entire upper end of the condensing distillation passage 9 becomes a residual steam opening 9b for dischargering residual steam. Here, Figure 4 is an explanatory diagram for explaining the configuration of the condensing distillation passage 9 in the condenser 10A shown in Figure 1. As with Figure 3, the direction of the lines indicated in Figure 4 for the condensation distillation passage 9 indicates the direction of the fins provided in the condensation distillation passage 9.

[0025] <Steam supply header> The steam supply header 3 is provided on the bottom surface of the heat exchanger block 1 to supply steam to the condensation distillation passages 9. As shown in Figures 1 and 2, the steam supply header 3 is provided so as to cover the entire bottom surface of the heat exchanger block 1 and is configured to communicate with all of the condensation distillation passages 9 formed in the heat exchanger block 1.

[0026] <Residual Steam Header> The residual vapor header 4 is for removing the residual vapor distilled in the condensation distillation passage 9, and is provided on the top surface of the heat exchanger block 1 so as to cover the residual vapor opening 9b. In the condenser 10A of this embodiment, as shown in Figures 1, 2, and 4, the residual steam opening 9b is configured to open in a part of the top surface of the heat exchanger block 1. Therefore, the residual steam header 4 is provided in a part of the width direction x of the top surface of the heat exchanger block 1 so as to cover the area where the residual steam opening 9b is open. However, as described above, if the condensation distillation passage 9 does not have a concentration passage 39 and a central passage 41, and the entire upper end of the condensation distillation passage 9 becomes the residual steam opening 9b for discharge of residual steam, the residual steam header 4 may be provided so as to cover the entire top surface of the heat exchanger block 1, although this is not shown in the figures.

[0027] <Liquid reservoir section> The liquid reservoir section 2 has an internal space for storing the liquid supplied to the evaporation passage 8 and the liquid that flows out of the evaporation passage 8.

[0028] The liquid reservoir 2 is provided on at least one side surface of the heat exchanger block 1 in the width direction x (i.e., the direction perpendicular to the stacking direction z), such that the internal space is defined by the side surface and the inner circumferential surface of the liquid reservoir 2. The liquid reservoir 2 only needs to be provided on at least one side surface of the heat exchanger block 1 in the width direction x, but it is preferable that one is provided on each of the two sides of the heat exchanger block 1 in the width direction x, as shown in Figures 1 and 2.

[0029] The liquid reservoir 2 shown in Figures 1 and 2 is provided to cover the entire area of ​​each side surface in the width direction x of the heat exchanger block 1. However, for example, if both the area where the liquid inlet opening 15a and the gas-liquid two-phase flow opening 17a of the evaporation passage 8 are provided on the side surface in the width direction x of the heat exchanger block 1 are included within the internal space of the liquid reservoir 2, the liquid reservoir 2 may be provided to cover only a part of the width direction x of the heat exchanger block 1. In other words, the liquid reservoir 2 only needs to be provided to cover both the liquid inlet opening 15a for supplying liquid to the evaporation passage 8 provided on the side surface in the width direction x of the heat exchanger block 1 and the gas-liquid two-phase flow opening 17a for discharging the gas-liquid two-phase flow from the evaporation passage 8.

[0030] There are no particular restrictions on the shape of the liquid reservoir 2. For example, it can be installed on one side of the heat exchanger block 1 in the width direction x, and the internal space for storing the liquid supplied to the evaporation passage 8 can be defined by the side and the inner surface of the liquid reservoir 2. Figures 1 and 2 show examples in which hollow semi-cylindrical liquid reservoirs 2 are provided on one side and the other side of the heat exchanger block 1, respectively.

[0031] The liquid reservoir 2 has a liquid supply port 6 for introducing liquid from the outside into the internal space of the liquid reservoir 2, a steam outlet 5 for removing steam from the internal space of the liquid reservoir 2, and a liquid outlet 7 for removing the liquid stored in the internal space of the liquid reservoir 2. As shown in Figures 1 and 2, the steam outlet 5 for removing steam from the internal space of the liquid reservoir 2 is provided at the top of the liquid reservoir 2, and the liquid outlet 7 for removing the liquid stored in the internal space of the liquid reservoir 2 is provided at the bottom of the liquid reservoir 2. The liquid supply port 6 for introducing liquid from the outside into the internal space of the liquid reservoir 2 is provided on the side of the liquid reservoir 2.

[0032] [Operation Description] Next, the operation of the fractional reducer 10A of this embodiment, configured as described above, will be explained with reference to Figures 1 to 4.

[0033] First, a refrigerant liquid (Lc) is stored in the internal space of the liquid reservoir 2 (hereinafter sometimes simply referred to as "inside the liquid reservoir 2"). The liquid (Lc) stored in the liquid reservoir 2 is introduced into the evaporation passage 8 through the liquid inlet opening 15a of the heat exchanger block 1 and the liquid inlet passage 15.

[0034] On the other hand, the multi-component vapor (Vw) to be subjected to condensate distillation is introduced into the condensate distillation passage 9 from an external source via the vapor supply header 3.

[0035] The liquid (Lc) introduced into the evaporation passage 8 receives heat from the fluid flowing through the condensation and distillation passage 9, and a portion of it evaporates. Due to this evaporation, the density of the fluid flowing through the evaporation passage 8 becomes less than the density of the liquid stored in the liquid reservoir 2, creating an upward flow. This flow is then returned to the liquid reservoir 2 as a gas-liquid two-phase fluid (Lc + Vc) through the gas-liquid two-phase fluid outlet 17 of the heat exchanger block 1 via the gas-liquid two-phase fluid outlet 17a. The gas (Vc) discharged from the gas-liquid two-phase fluid outlet 17a is discharged to the outside through the vapor outlet 5 of the liquid reservoir 2, and the liquid (Lc) is stored again in the liquid reservoir 2.

[0036] Meanwhile, the vapor (Vw) introduced into the condensation distillation passage 9 rises within the passage, and as it rises, a portion of it condenses due to heat exchange with the fluid flowing through the evaporation passage 8, producing a descending liquid. Thus, countercurrent contact occurs between the rising gas and the descending liquid, and as the vapor rises, the low-boiling point components become concentrated and are removed to the outside through the residual vapor opening 9b and the residual vapor header 4 at the top.

[0037] On the other hand, the liquid produced by condensation in the condensation distillation passage 9 becomes concentrated with high-boiling-point components as it descends, and is discharged via the steam supply header 3 at the bottom.

[0038] In the fractional condenser 10A of this embodiment, as described above, the liquid reservoir 2 for storing the liquid (Lc) introduced into the evaporation passage 8 is provided on at least one side of the heat exchanger block 1 in the width direction x. Therefore, it is not necessary to house the entire heat exchanger block 1 in a pressure vessel for storing the liquid (Lc), as is the case with conventional fractional condensers. As a result, the fractional condenser 10A of this embodiment can have a smaller footprint compared to conventional fractional condensers in which the entire heat exchanger block 1 is housed in a pressure vessel. For example, the fractional condenser 10A of this embodiment can reduce the area required for installation (i.e., footprint) by about 20% compared to the conventional fractional condenser described above, realizing a compact fractional condenser 10A in which the heat exchanger block 1 and the liquid reservoir 2 as a liquid reservoir container for the refrigerant are integrated.

[0039] Furthermore, while the piping for extracting steam from the residual steam header of the condenser 10A had to pass through the pressure vessel in the prior art, this is no longer necessary, resulting in a simpler design.

[0040] <Second Embodiment> Next, a fractional reducer according to a second embodiment of the present invention will be described with reference to Figure 5. Figure 5 is a schematic plan view showing the fractional reducer of the second embodiment. In this second embodiment, the same reference numerals are used for parts that are the same as those in the first embodiment, and their descriptions may be omitted.

[0041] As shown in Figure 5, the condenser 10B of the second embodiment is a condenser 10B that, like the condenser 10A of the first embodiment (see Figure 2), is equipped with a heat exchanger block 1, a steam supply header 3, a residual steam header 4, and a liquid reservoir 2.

[0042] In the second embodiment of the condenser 10B, liquid reservoirs 2 are provided on one side and the other side of the heat exchanger block 1 in the width direction x. The condenser 10B is equipped with a connecting pipe 13 for circulating the liquid (Lc) in the two liquid reservoirs 2 provided on one side and the other side of the heat exchanger block 1.

[0043] As in the second embodiment of the condenser 10B, by providing a connecting pipe 13 for circulating the liquid (Lc) in the two liquid reservoirs 2, the liquid level heights of the liquid (Lc) stored in the two liquid reservoirs 2 can be made equal. For example, if the liquid level heights of the liquid (Lc) stored in the liquid reservoir 2 provided on one side of the heat exchanger block 1 and the liquid reservoir 2 provided on the other side of the heat exchanger block 1 are different, a pressure difference will occur at the liquid inlet opening 15a and the gas-liquid two-phase flow opening 17a of the heat exchanger block 1, which may cause the flow in the evaporation passage 8 to become uneven. If the uneven flow in the evaporation passage 8 becomes extremely severe, the liquid may completely evaporate in a part of the evaporation passage 8, causing solidified impurity components in the gas-liquid two-phase fluid to accumulate and block the flow path. When the above-mentioned problems occur, the flow becomes uneven and the heat transfer performance deteriorates. By providing a connecting pipe 13 for circulating the liquid (Lc) in the two liquid reservoirs 2, the flow in the evaporation passage 8 becomes uniform, effectively suppressing the occurrence of the problems described above, and enabling more efficient operation of the condenser 10B.

[0044] As shown in Figure 5, the connecting pipe 13 for circulating the liquid (Lc) in the two liquid reservoirs 2 is connected to the bottom surface of each liquid reservoir 2 and is composed of piping that connects the two liquid reservoirs 2. In the second embodiment of the condenser 10B, a liquid outlet 7 for taking out the liquid (Lc) from the liquid reservoirs 2 is provided in the middle of the connecting pipe 13 that connects the two liquid reservoirs 2. Therefore, when taking out the liquid (Lc) from the liquid outlet 7, the liquid (Lc) can be taken out simultaneously from both liquid reservoirs 2 via the connecting pipe 13. Therefore, when taking out the liquid (Lc) from the liquid outlet 7, the liquid level of the liquid (Lc) stored in the two liquid reservoirs 2 can be made equal.

[0045] <Third Embodiment> Next, a top-mounted reducer according to a third embodiment of the present invention will be described with reference to Figure 6. Figure 6 is a schematic plan view showing a top-mounted reducer according to a third embodiment of the present invention. In this third embodiment, the same reference numerals are used for parts that are the same as those in the first embodiment, and their descriptions may be omitted.

[0046] As shown in Figure 6, the top condenser 110 of the third embodiment is a top condenser 110 provided at the top 31 of the distillation column for generating reflux liquid. The top condenser 110 comprises the condenser 10A of the first embodiment shown in Figure 1, an introduction section 12A having a communication section 12 that connects the vapor supply header 3 of the condenser 10A to the top 31 of the distillation column, and a liquid collector 20 for collecting the liquid flowing down the introduction section 12A through the condensation distillation passage 9.

[0047] In the top condenser 110 configured as described above, the steam supplied from the top 31 of the distillation column to the condenser 10A passes through the steam rise path 23 of the liquid collector 20, through the communication section 12 and the steam supply header 3, and is supplied to the heat exchanger block 1. The liquid flowing down from the heat exchanger block 1 is collected in the liquid collector 20 after passing through the steam supply header 3 and the communication section 12.

[0048] The liquid collector 20 consists of, for example, a liquid collection channel 21 for collecting the flowing liquid, an umbrella 22 for guiding the flowing liquid into the liquid collection channel 21, a steam rise channel 23 which serves as a passage for steam inside the tower to pass through and rise, a circumferential channel 24 provided on the tower wall 30 and connected to the liquid collection channel 21, and a liquid extraction pipe 25 connected to the circumferential channel 24 for extracting the liquid.

[0049] In the tower top reducer 110 configured as described above, the liquid that flows down through the steam supply header 3 is collected in the liquid collection path 21 by the umbrella 22, collected from each liquid collection path 21 in the peripheral path 24, and extracted from the liquid extraction pipe 25 connected to the peripheral path 24.

[0050] <Fourth Embodiment> Next, an air separation device according to a fourth embodiment of the present invention will be described with reference to Figure 7. Figure 7 is a schematic diagram illustrating the air separation device of the fourth embodiment and is a system diagram showing the overall configuration of the air separation device. In this fourth embodiment, the same reference numerals are used for parts that are the same as those in the third embodiment, and their descriptions may be omitted.

[0051] As shown in Figure 7, the air separation apparatus 200 of the fourth embodiment is an air separation apparatus consisting of a double rectification system that extracts nitrogen, oxygen, and argon from air. The air separation apparatus of the fourth embodiment is equipped with the top condenser 110 of the third embodiment shown in Figure 6 as the top condenser of the argon column.

[0052] The air separation apparatus 200 of the fourth embodiment is a device for extracting nitrogen, oxygen, and argon from air, and its main components include an air compressor 40, a main heat exchanger 50, a distillation column consisting of a high-pressure column 60, a low-pressure column 80, a crude argon column 90, and a deoxidation column 100, a main condenser 70, a top condenser 110, pumps 81 and 101, and an outer tank 120. In the air separation apparatus 200 shown in Figure 7, the argon column is divided into a crude argon column 90 and a deoxidation column 100, and the top condenser 110 of the third embodiment described above is provided at the top of the deoxidation column 100.

[0053] Here, the main heat exchanger 50 is for exchanging heat with the raw air. The main condenser 70 is for exchanging heat between the bottom liquid of the low-pressure column 80 and the steam supplied from the top of the high-pressure column 60. The outer tank 120 is for keeping the distillation columns and heat exchangers that make up the air separation unit 200 cool, and the outer tank 120 may be, for example, one that has an insulating material.

[0054] In the air separation unit 200 shown in Figure 7, for example, nitrogen is recovered from the main heat exchanger 50 as low-pressure nitrogen gas (LPGN) and medium-pressure nitrogen gas (MPGN). Oxygen is recovered as oxygen gas (GO). In addition, liquefied oxygen (LO) is recovered from the main condenser 70.

[0055] In the air separation unit 200, first, the raw air is compressed by the air compressor 40, and the compressed raw air is introduced into the high-pressure column 60 and the low-pressure column 80 for distillation. Then, the argon-enriched flow is taken from the low-pressure column 80 and sent to the crude argon column 90. The top of the crude argon column 90 is in communication with the bottom of the deoxidation column 100, and the liquid accumulated at the bottom of the deoxidation column 100 is supplied to the top of the crude argon column 90 by the pump 101. In addition, a top condenser 110 for generating reflux liquid is provided at the top of the deoxidation column 100.

[0056] In the crude argon column 90 and the deoxidation column 100, oxygen, a high-boiling-point component, concentrates at the bottom, while argon, a low-boiling-point component, concentrates towards the top. In the top condenser 110 located at the top of the deoxidation column 100, vapor from the deoxidation column 100 is introduced into the condensation distillation passage 9 (see Figure 6, hereafter the same) of the heat exchanger block 1 through the liquid collector 20 (see Figure 6, hereafter the same). The vapor introduced into the condensation distillation passage 9 is partially liquefied as heat is removed by the refrigerant passing through the evaporation passage 8 (see Figure 6, hereafter the same) of the heat exchanger block 1, and then comes into contact with the liquid in a countercurrent. As a result, in the heat exchanger block 1, nitrogen, the impurity component with the lowest boiling point, concentrates at the top, while argon, a high-boiling-point component, concentrates at the bottom. The concentrated nitrogen vapor (PG) at the top of heat exchanger block 1 is discharged from the top of heat exchanger block 1, and high-purity liquid argon (LAr) is extracted from the bottom of heat exchanger block 1.

[0057] Liquid air supplied from the bottom of the high-pressure tower 60 is used as the refrigerant for the top condenser 110. Specifically, liquid air is supplied to the top condenser 110 from the bottom of the high-pressure tower 60 and stored in a liquid reservoir 2 located on the side of the heat exchanger block 1. The stored liquid air flows into the evaporation passage 8, receives heat, and a portion of it evaporates. The vapor generated by evaporation is removed from a vapor outlet 5 (see Figure 6, hereafter the same) located in the liquid reservoir 2 and supplied to the low-pressure tower 80. In addition, liquid air stored in the liquid reservoir 2 is removed from a liquid outlet 7 (see Figure 6, hereafter the same) located at the bottom of the liquid reservoir 2 and supplied to the low-pressure tower 80 in the same way as the vapor removed from the vapor outlet 5.

[0058] Here, for comparison with the air separation apparatus 200 of the fourth embodiment, an example of an air separation apparatus using a conventional partial condenser as a top partial condenser of an argon column will be described with reference to Figure 8. Figure 8 is a schematic diagram illustrating an air separation apparatus using a conventional partial condenser as a top partial condenser of an argon column, and is a system diagram showing the general configuration of a part of the air separation apparatus. The air separation apparatus 300 shown in Figure 8 is a comparative example in which a partial condenser configured in the same way as the partial condenser described in Patent Document 1 (Japanese Patent No. 7308237) is applied as the top partial condenser 310 of an argon column (more specifically, a deoxidation column 100 as an argon column).

[0059] The top condenser 310 in the air separation device 300 shown in Figure 8 comprises a heat exchanger block 301, a container 311 surrounding the top and all sides of the heat exchanger block 301, and a gas-liquid separation section 312. In the top condenser 310, steam from the deoxidation tower 100 is introduced into the heat exchanger block 301 through the gas-liquid separation section 312. The steam introduced into the heat exchanger block 301 is partially liquefied within the heat exchanger block 301, with low-boiling-point nitrogen concentrated at the top and high-boiling-point argon concentrated at the bottom. As a result, nitrogen-concentrated steam is extracted from the top and sides of the heat exchanger block 301, and high-purity liquid argon is extracted from the bottom of the heat exchanger block 301.

[0060] Liquid air supplied from the bottom of the high-pressure tower 60 is used as the refrigerant for the top condenser 310. The liquid air used as the refrigerant is supplied to and stored in a container 311 surrounding the heat exchanger block 301. Some of the liquid air stored in the container 311 evaporates as it passes through the heat exchanger block 301. The resulting vapor is then extracted from the top of the container 311, and the liquid air is extracted from the bottom of the container 311. The vapor and liquid air extracted from the container 311 are supplied to the low-pressure tower 80.

[0061] In a conventional top-of-the-column condenser 310 using a condenser as shown in Figure 8, the entire heat exchanger block 301 is housed in a pressure vessel 311, resulting in a larger condenser size. Furthermore, when the entire heat exchanger block 301 is housed in the vessel 311, complex processing such as passing piping through the vessel 311 is required, increasing the manufacturing cost.

[0062] On the other hand, in the fourth embodiment of the air separation device 200 of the present invention, as shown in Figure 7, the top condenser 110 has a liquid reservoir 2 on the side of the heat exchanger block 1, which allows for a smaller condenser size. Furthermore, the top condenser 110 shown in Figure 7 does not require complex processing such as passing piping through the liquid reservoir 2, thus reducing the manufacturing cost of the top condenser 110 and the outer tank 120. [Explanation of Symbols]

[0063] 1…Heat exchanger block, 2…Liquid reservoir, 3…Steam supply header, 4…Residual steam header, 5…Steam outlet, 6…Liquid supply port, 7…Liquid outlet, 8…Evaporation passage, 9…Condensing and distillation passage, 9a…Steam inlet opening, 9b…Residual steam opening, 10A, 10B…Collapser, 12…Communication section, 12A…Inlet section, 13…Communication pipe, 15…Liquid inlet passage, 15a…Liquid inlet opening, 17…Gas-liquid two-phase fluid outlet passage, 17a…Gas-liquid two-phase flow opening 17a, 20…Liquid collector, 21…Liquid collection passage, 22… Umbrella, 23...Steam rising path, 24...Circular path, 25...Liquid outlet pipe, 30...Column wall, 31...Column top, 39...Collection passage, 41...Central passage, 40...Air compressor, 50...Main heat exchanger, 60...High pressure column, 70...Main condenser, 80...Low pressure column, 81, 101...Pumps, 90...Crude argon column, 100...Deoxidation column, 110...Column top condenser, 120...Outer tank, 200...Air separation device, 300...Air separation device, 301...Heat exchanger block, 310...Column top condenser, 311...Container, 312...Gas-liquid separation section.

Claims

1. A heat exchanger block having an evaporation passage through which a liquid to be evaporated flows, and a condensation distillation passage through which vapor for condensation distillation, which exchanges heat with the liquid flowing through the evaporation passage, A steam supply header for supplying the steam to the condensation distillation passage, A residual vapor header for extracting the residual vapor distilled in the aforementioned condensation distillation passage, It comprises a liquid reservoir having an internal space for storing the liquid supplied to the evaporation passage and the liquid that has flowed out of the evaporation passage, The heat exchanger block is a plate-fin type heat exchanger block in which the evaporation passages and condensation distillation passages, which consist of plates and fins, are alternately stacked. The steam supply header is provided on the bottom surface of the heat exchanger block, The residual steam header is provided on the top surface of the heat exchanger block, The liquid reservoir is provided on at least one side surface in the width direction perpendicular to the stacking direction of the heat exchanger block, covering both an opening for supplying liquid to the evaporation passage provided on that side surface and an opening for discharging the gas-liquid two-phase flow from the evaporation passage, and the internal space is defined by the side surface and the inner circumferential surface of the liquid reservoir. The liquid reservoir is characterized by having a liquid supply port for introducing liquid from the outside into the internal space, a steam outlet for removing steam from the internal space, and a liquid outlet for removing the liquid stored in the internal space.

2. The heat exchanger block is provided with liquid reservoirs on one side and the other side in the width direction, and is provided with a connecting pipe for circulating the liquid in the two liquid reservoirs provided on the one side and the other side, as described in claim 1.

3. A top condenser provided at the top of a distillation column, comprising: a condenser according to claim 1 or 2; an introduction section having a communication section that connects the vapor supply header of the condenser to the top of the distillation column; and a liquid collector for collecting the liquid flowing down through the condensation distillation passage to the introduction section.

4. An air separation apparatus comprising a double rectification system for extracting nitrogen, oxygen, and argon from air, characterized in that the top condenser described in claim 3 is provided as the top condenser of the argon column.

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