JP2022139461A - Partial condenser, overhead partial condenser, and air separation device - Google Patents

Abstract

To provide a partial condenser that is excellent in heat exchange efficiency and mass transfer efficiency and can improve the heat exchange efficiency and the mass transfer efficiency even when introduced steam contains non-condensable components, and to provide an overhead partial condenser using the partial condenser, and an air separation device provided with the overhead partial condenser.SOLUTION: A partial condenser 1 according to the present invention comprises a heat exchanger block 7 having evaporation passages 3 and condensation distillation passages 5, a container 9 for immersing the heat exchanger block 7 therein and storing the liquid flowing into the evaporation passages 3, a steam supply header 11 for supplying steam to the bottom of the heat exchanger block 7, and a residual steam header 13 for taking out residual steam distilled in the condensation distillation passages 5. Residual steam openings 5b serving as outlets for residual steam are provided on the top surface of the heat exchanger block 7, and the residual steam header 13 is provided on the top surface of the heat exchanger block 7. Gas-liquid two-phase flow openings 17a serving as outlets for a gas-liquid two-phase fluid from the evaporation passages 3 are provided in a region not covered with the residual steam header 13.SELECTED DRAWING: Figure 1

Description

The present invention provides a partial condenser composed of a heat exchanger block having an evaporation passage and a condensation distillation passage, an overhead partial condenser using the partial condenser, and an air separation apparatus comprising the overhead partial condenser. It is about.

Dephlegmators are used as separators or condensers to partially condense vapor. A plate-fin type heat exchanger in which plates and fins form evaporation passages and condensing distillation passages is applied to such a partial condenser.

In the partial condenser, liquid is supplied as refrigerant to the evaporation passage, and multicomponent vapor is introduced from the bottom into the condensation distillation passage. The vapor introduced into the condensing distillation passage is partially liquefied by heat exchange with the refrigerant in the evaporation passage, and the vapor and the liquid come into contact with each other in a countercurrent flow to effect mass transfer. Therefore, the steam rises while concentrating the low boiling point components, and the resulting liquid descends while concentrating the high boiling point components.

Patent Document 1 discloses that such a partial condenser (described as a "reflux condenser" in Patent Document 1 and the same applies to Patent Document 2) is used as a top condenser of a crude argon column of an air separation unit. It is
Further, Patent Document 2 describes a partial condenser with a heat exchanger block consisting of an evaporation passage and a condensation distillation passage, and discloses a means for introducing steam into the condensation distillation passage and a means for extracting steam in which low boiling point components are concentrated. It is

JP-A-2009-30966 JP 2008-39386 A

In the partial condenser disclosed in Patent Document 2, a header for introducing steam into the condensing and distillation passage is provided on the bottom surface of the heat exchanger block, and the steam in which the low boiling point components are concentrated in the condensing and distillation passage is led out. headers are provided on the upper side of the heat exchanger block.
In this case, the steam introduced into the condensation distillation passage from the bottom flows upward while condensing the low boiling point components as it condenses. must turn almost 90° to the side where the

For this reason, a distributor is provided in the condensing and distillation passage to greatly change the direction of the flow, and heat exchange and mass transfer cannot be performed sufficiently in this portion, resulting in a problem of reduced heat exchange efficiency and mass transfer efficiency. rice field.
Moreover, when the steam introduced into the condensation distillation passage contains non-condensable component gas, there is a problem that the non-condensable component gas stays in the distributor, further lowering the efficiency.

The present invention has been made to solve such problems, and is excellent in heat exchange efficiency and mass transfer efficiency, and improves heat exchange efficiency and mass transfer efficiency even when the introduced steam contains non-condensable components. It is an object of the present invention to provide a partial condenser capable of producing a partial condenser, an overhead partial condenser using the partial condenser at the top of a distillation column, and an air separation apparatus equipped with the overhead partial condenser.

(1) The partial condenser according to the present invention has an evaporation passage through which the liquid to evaporate flows and a condensation distillation passage through which the vapor for condensing and distilling the liquid flowing through the evaporation passage flows by exchanging heat. an exchanger block, a container for immersing the heat exchanger block and storing the liquid flowing into the evaporation passage, and a container provided on the bottom surface of the heat exchanger block for supplying the vapor to the condensing distillation passage. and a residual vapor header for removing residual vapor distilled in the condensing distillation passage,
A residual steam opening serving as an outlet for the residual steam is provided on the top surface of the heat exchanger block, and the residual steam header is provided on the top surface of the heat exchanger block so as to cover the residual steam opening. and a gas-liquid two-phase flow opening serving as an outlet for the gas-liquid two-phase fluid from the evaporation passage is provided in a region not covered with the residual steam header.

(2) Further, in the apparatus described in (1) above, the residual steam header is provided so as to cover the entire top surface of the heat exchanger block, and the gas-liquid two-phase flow opening is the heat exchanger block. It is characterized by being provided on the upper side surface of the.

(3) Further, in the apparatus described in (1) above, the heat exchanger block has fins for concentrating the residual steam on a part of the top surface of the heat exchanger block, and the residual steam opening is provided at a portion concentrated by the fins, and the gas-liquid two-phase flow opening is provided in a region of the top surface not covered with the residual steam header.

(4) Further, the overhead partial condenser according to the present invention is provided at the top of the distillation column,
The partial condenser according to any one of the above (1) to (3), a bottom plate connected to the steam supply header of the partial condenser and connected to the wall of the distillation column, and the steam supply header. and a liquid collector for collecting liquid flowing down through.

(5) Further, an air separation apparatus according to the present invention is an air separation apparatus comprising a double rectification system for extracting nitrogen, oxygen, and argon from air, wherein the overhead partial condenser described in (4) above is used. It is characterized by being provided as an overhead partial condenser of an argon column.

In the partial condenser according to the present invention, a residual steam opening serving as an outlet for residual steam is provided on the top surface of the heat exchanger block, and the residual steam header covers the heat exchanger block so as to cover the residual steam opening. Since it is provided on the top surface of the condensing distillation passage, heat exchange and mass transfer can be performed over the entire length of the condensing distillation passage without the need to provide a distributor or the like that greatly changes the flow direction in the condensing distillation passage. Therefore, the heat exchange efficiency and the mass transfer efficiency are excellent, and the heat exchange efficiency and the mass transfer efficiency can be improved even when the introduced steam contains the non-condensable component gas.

FIG. 2 is an explanatory diagram of a dephlegmator according to one embodiment of the present invention; FIG. 2 is an explanatory diagram of a condensation distillation passage (a) and an evaporation passage (b) of the partial condenser shown in FIG. 1; FIG. 2 is an explanatory diagram when the partial condenser shown in FIG. 1 is used as a top partial condenser provided at the top of a distillation column. It is explanatory drawing of another aspect of a condensation distillation passage (a) and an evaporation passage (b). FIG. 5 is an explanatory diagram when the partial condenser having the condensation distillation passage and the evaporation passage shown in FIG. 4 is used as a top partial condenser provided at the top of the distillation column. FIG. 5 is an explanatory view when the overhead partial condenser shown in FIG. 4 is applied to an air separation device;

As shown in FIG. 1, the partial condenser 1 according to the present embodiment includes an evaporation passage 3 through which a liquid to evaporate flows, and a vapor that exchanges heat with the liquid flowing through the evaporation passage 3 and is condensed and distilled. a container 9 for immersing the heat exchanger block 7 and storing the liquid flowing into the evaporation passage 3; It comprises a steam feed header 11 for supplying steam to the condensing distillation passage 5 and a residual steam header 13 for removing residual steam distilled in the condensing distillation passage 5.
Each configuration will be described in detail below.
The arrows in FIG. 1 indicate the direction of fluid flow. Further, V attached to the arrow indicates vapor, and L indicates liquid. W attached to V and L indicates that the fluid is warm, and c indicates that it is cold. Furthermore, i attached to w and c indicates that the fluid is in, and o indicates that the fluid is out.

<Heat exchanger block>
The heat exchanger block 7 is composed of plates and fins, and has an evaporation passage 3 through which the liquid to evaporate flows and a condensation distillation passage 5 through which the vapor for condensing and distilling the liquid flowing through the evaporation passage 3 flows. have.

The evaporation passage 3 is provided from the bottom to the top of the heat exchanger block 7 as shown in FIGS. 1 and 2(b). As shown in FIG. 2(b), the lower end of the evaporation passage 3 is provided with a liquid introduction passage 15 for introducing the liquid in the container 9, and the entrance of the liquid introduction passage 15 is provided with a liquid introduction opening 15a. It is
A gas-liquid two-phase fluid lead-out passage 17 for leading out a gas-liquid two-phase fluid is provided at the upper end of the evaporation passage 3, and an opening 17a for gas-liquid two-phase flow is provided at the outlet of the gas-liquid two-phase fluid lead-out passage 17. is provided. The area where the gas-liquid two-phase flow openings 17 a are provided is the area of the upper side surface of the heat exchanger block 7 that is not covered with the residual steam header 13 .
As shown in FIG. 2B, the liquid introduction path 15 and the gas-liquid two-phase fluid outlet path 17 of the evaporation passage 3 are formed by turning the fins sideways. The direction of the line drawn in each passage in FIG. 2 indicates the direction of the fins provided in the passage.

The condensation distillation passage 5 is provided from the lower end to the upper end of the heat exchanger block 7, as shown in FIGS. 1 and 2(a). The lower end of the condensation distillation passage 5 serves as a steam introduction opening 5a for introducing steam, and the upper end serves as a residual steam opening 5b for leading out residual steam. Residual steam openings 5 b are located on the top surface of heat exchanger block 7 .

In this embodiment, since the residual steam opening 5b is provided on the top surface of the heat exchanger block 7, it is necessary to change the direction of the steam flowing through the condensation distillation passage 5 as shown in FIG. 2(a). Therefore, there is no need to provide a distributor or the like. Therefore, there is no adverse effect on heat exchange or mass transfer caused by providing a distributor or the like. Further, even if the steam introduced into the condensation distillation passage 5 contains non-condensable component gas, the non-condensable component gas does not stay in the distributor or the like, so there is a problem that the efficiency is lowered. do not do.

<Container>
The container 9 is for immersing the heat exchanger block 7 and storing the liquid flowing into the evaporation passage 3 . A gas discharge pipe 19 for discharging the gas in the container 9 is provided on the upper part of the container 9 . A liquid supply pipe 20 for supplying liquid into the container 9 is also provided.

<Steam supply header>
A steam supply header 11 is provided on the bottom surface of the heat exchanger block 7 to supply steam to the condensing distillation passage 5 . As shown in FIG. 1, the steam supply header 11 is provided so as to cover the entire bottom surface of the heat exchanger block 7, and is provided so as to communicate with all the condensation distillation passages 5 formed in the heat exchanger block 7. ing.

<Residual steam header>
The residual steam header 13 is for taking out the residual steam distilled in the condensing distillation passage 5, and is provided on the top surface of the heat exchanger block 7 so as to cover the residual steam opening 5b.
In the example shown in FIG. 1, the residual steam header 13 is provided so as to cover the entire top surface of the heat exchanger block 7, and the residual steam header 13 is provided with a residual steam extraction pipe 21 for extracting the residual steam to the outside. ing.

[Description of operation]
Next, the operation of the dephlegmator 1 according to the present embodiment configured as described above will be described with reference to FIG.
A liquid (Lc) serving as a refrigerant is stored in the container 9 , and this liquid (Lc) passes through the liquid introduction passage 15 from the liquid introduction opening 15 a of the heat exchanger block 7 and is introduced into the evaporation passage 3 .
On the other hand, the multi-component vapor (Vw) to be condensed and distilled is introduced from the outside into the condensed distillation passage 5 via the vapor supply header 11 .
The liquid (Lc) introduced into the evaporation passage 3 receives heat from the fluid flowing through the condensation distillation passage 5 and is partially evaporated. Due to the evaporation, the density of the fluid flowing through the evaporation passage 3 becomes lower than the density of the liquid stored in the container 9, causing an upward flow, and the gas-liquid two-phase fluid lead-out passage 17 of the heat exchanger block 7. is returned to the container 9 as a gas-liquid two-phase fluid (Lc+Vc) from the gas-liquid two-phase flow opening 17a. The gas (Vc) discharged from the gas-liquid two-phase flow opening 17a is discharged outside from the gas discharge pipe 19 of the container 9, and the liquid (Lc) is stored in the container 9 again.

On the other hand, the vapor (Vw) introduced into the condensation distillation passage 5 rises in the passage, and as it rises, it exchanges heat with the fluid flowing through the evaporation passage 3, and part of it condenses to produce a descending liquid. As a result, countercurrent contact occurs between the ascending gas and the descending liquid, and as the vapor rises, the low-boiling point components are concentrated. 9 is taken out.
On the other hand, the liquid condensed in the condensing distillation passage 5 is condensed in high boiling point components as it descends, and is discharged through the vapor supply header 11 at the bottom.

As shown in FIG. 2(a), the condensing and distillation passage 5 at this time does not change the flow direction, so that the gas-liquid can efficiently come into contact with the entire height of the heat exchanger block 7, and the flow can be controlled. Since it is smooth, even if non-condensable components are contained, the component gas can be discharged without being retained. The efficiency improvement corresponds to, for example, reducing the heat transfer area by 10% or more, and can contribute to the size reduction of the heat exchanger block 7 .

The partial condenser 1 configured as described above can be used, for example, as a top partial condenser 23 provided at the top of a distillation column, as shown in FIG. A specific configuration when used as the overhead partial condenser 23 will be described with reference to FIG. In FIG. 3, the same parts as in FIG. 1 are denoted by the same reference numerals.

In the case of the overhead partial condenser 23 , the vapor feed header 11 is fixed to the bottom plate 25 of the vessel 9 , and a liquid collector 27 is provided below the bottom plate 25 for collecting the liquid flowing down through the vapor feed header 11 . The liquid collector 27 includes, for example, a liquid collection path 29 for collecting the liquid that has flowed down, an umbrella 31 for guiding the liquid that has flowed down to the liquid collection path 29, and a passage for the vapor in the column to pass through and rise. , a circuit 35 provided in the tower wall and connected to the liquid collecting passage 29, and a liquid take-out pipe 37 connected to the circuit 35 for taking out the liquid.

In the overhead partial condenser 23 configured as described above, the liquid (Lw) flowing down through the vapor supply header 11 is guided by the umbrella 31 and collected in the liquid collecting passages 29. From each liquid collecting passage 29, It is led to the peripheral path 35 and taken out by a liquid take-out pipe 37 connected to the peripheral path 35 .

In the above-described embodiment, the residual steam header 13 is provided over the entire area of the top surface of the heat exchanger block 7, and the gas-liquid two-phase flow openings 17a are provided on the upper side surface of the heat exchanger block 7. Alternatively, the residual steam header 13 may be provided on a portion of the top surface of the heat exchanger block 7, and the gas-liquid two-phase flow opening 17a may be provided in a region of the top surface where the residual steam header 13 is not provided.

An example of the configuration of the condensation distillation passage 5 and the evaporation passage 3 in this case is shown in FIG. As shown in FIG. 4( a ), the condensing distillation passage 5 has a central passage 39 for centralizing the condensing distillation passages 5 and a central passage 41 communicating with the central passage 39 .
As shown in FIG. 4B, the evaporation passage 3 is provided with branch passages 43 on both sides of the top surface of the heat exchanger block 7 so as to avoid the central portion of the top surface of the heat exchanger block 7 . A branch passage 43 is connected to the gas-liquid two-phase fluid lead-out passage 17 .
Even in such a mode, the same effects as those shown in FIGS. 1 and 2 can be obtained.

FIG. 5 shows an example in which the overhead partial condenser 23 is used instead of the partial condenser 1 in which the condensation distillation passage 5 and the evaporation passage 3 are arranged as shown in FIG. In FIG. 5, the same reference numerals are given to the same parts as in FIG. 3 and the corresponding parts.

Next, the air separation apparatus provided with the overhead partial condenser 23 will be described with reference to FIG. In FIG. 6, the same parts as in FIG. 3 are denoted by the same reference numerals.
The air separation unit 45 consists of a double rectification system for extracting nitrogen, oxygen, and argon from air, and is mainly composed of a high pressure column 47, a low pressure column 49, and a main condenser disposed below the low pressure column 49. A vessel 51 and an argon column 53 are provided. A top partial condenser 23 is provided at the top of the argon column 53 .

In the air separation unit 45 as described above, the feed air is sent to the bottom of the high pressure column 47 and distilled to be separated into nitrogen gas and oxygen-rich liquid air (oxygen-enriched liquid air). From the central portion of the low-pressure column 49, a raw material gas (argon-containing oxygen gas) composed mainly of oxygen, containing 5 to 15% argon and a small amount of nitrogen is extracted and introduced into the bottom of the argon column 53. .

The argon-containing oxygen gas introduced into the argon column 53 rises in the argon column 53 to concentrate the argon and is introduced into the partial condenser 1 .
The argon-enriched gas introduced into the partial condenser 1 evaporates the oxygen-enriched liquid air flowing through the evaporation passage 3, rises while condensing in the condensation distillation passage 5, reduces the high-boiling-point component oxygen, and reduces the Nitrogen, which is a boiling point component, is condensed and discharged from the residual vapor header 13 of the partial condenser 1 as argon gas (impurity gas).
On the other hand, the liquid condensed and descended in the condensing distillation passage 5 passes through the liquid collector 27 and is partially taken out as liquid argon as a product.

1 partial condenser 3 evaporation passage 5 condensation distillation passage 5a vapor introduction opening 5b residual vapor opening 7 heat exchanger block 9 vessel 11 vapor supply header 13 residual vapor header 15 liquid introduction passage 15a liquid introduction opening 17 gas-liquid two-phase fluid Lead-out passage 17a Gas-liquid two-phase flow opening 19 Gas discharge pipe 20 Liquid supply pipe 21 Residual vapor withdrawal pipe 23 Top partial condenser 25 Bottom plate 27 Liquid collector 29 Liquid collection passage 31 Umbrella 33 Vapor rise passage 35 Circuit 37 Liquid withdrawal Pipe 39 Collective Passage 41 Central Passage 43 Branch Passage 45 Air Separator 47 High Pressure Column 49 Low Pressure Column 51 Main Condenser 53 Argon Column

Claims (5)

A heat exchanger block having an evaporation passage through which a liquid to evaporate flows and a condensation distillation passage through which vapor for condensing and distilling the liquid flowing through the evaporation passage by exchanging heat with the vapor flows; and the heat exchanger block being immersed. a container for storing the liquid flowing into the evaporation passage while causing the vaporization, a steam supply header provided on the bottom surface of the heat exchanger block for supplying the steam to the condensation distillation passage, and the condensation distillation passage a residual vapor header for removing residual vapor distilled in the
A residual steam opening serving as an outlet for the residual steam is provided on the top surface of the heat exchanger block, and the residual steam header is provided on the top surface of the heat exchanger block so as to cover the residual steam opening. 2. A dephlegmator, wherein a gas-liquid two-phase flow opening serving as an outlet port for the gas-liquid two-phase fluid from said evaporation passage is provided in a region not covered by said residual steam header. 3. The residual steam header is provided to cover the entire top surface of the heat exchanger block, and the gas-liquid two-phase flow opening is provided on the upper side surface of the heat exchanger block. 1. The dephlegmator according to claim 1. The heat exchanger block has fins for concentrating the residual steam on a part of the top surface of the heat exchanger block, and the residual vapor opening is provided in the portion concentrated by the fins. 2. The dephlegmator of claim 1, wherein two-phase flow openings are provided in areas of said top surface not covered by said residual steam header. A top partial condenser provided at the top of a distillation column,
The partial condenser according to any one of claims 1 to 3, a bottom plate connected to the steam supply header of the partial condenser and connected to the column wall of the distillation column, and the steam flowing down through the steam supply header. and a liquid collector for collecting liquid. An air separation apparatus comprising a double rectification system for extracting nitrogen, oxygen and argon from air, wherein the overhead partial condenser according to claim 4 is provided as the overhead partial condenser of an argon column. separation device.

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