JP2000111244A - Flowing-down liquid film type condensation evaporator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a manufacturing cost and effectively utilize a thermosiphon by providing a liquid distributing means having a liquid distribution expediting function for uniformly introducing evaporating fluid to an evaporating passage above a heat exchanger core separately from the core. SOLUTION: A liquid distributing means 35 is provided with a gap above separately from a heat exchanger core 34, and hence the gap can be used as an introducing passage of oxygen gas evaporated to be vaporized at an evaporating passage 33. Accordingly, at the time of once stopping the evaporator or the like, even in the case of a condensing evaporator 30 dipped in a liquefied oxygen, the oxygen gas evaporated similarly to prior art can be introduced from above, and hence a liquefied oxygen can be circulated by a thermosiphon effect, and a function as the evaporator can be performed. Thus, since a conventional low cost heat exchanger core 34 can be used, a cost of the overall evaporator can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a falling liquid film type condensing evaporator, and more particularly, to a plate-fin type heat exchanger core in which condensing passages and evaporating passages are alternately provided adjacent to each other via a partition plate. A falling-film condensing evaporator provided with a liquid distribution means for uniformly distributing and introducing an evaporating fluid to an evaporating passage, particularly a plate fin type preferably used for a distillation column of an air liquefaction separation device. And a falling film condensing evaporator.

[0002]

2. Description of the Related Art In a double distillation column of an air liquefaction / separation apparatus, liquefied oxygen in the bottom of a low pressure distillation column (hereinafter, referred to as a low pressure column) or in a vessel communicating with the low pressure column, and a high pressure distillation column (hereinafter, high pressure column) are used. Column) is indirectly heat-exchanged with the nitrogen gas at the top of the double distillation column by means of a heat exchanger provided in the middle part of the double distillation column to evaporate part of the liquefied oxygen to produce a rising gas in the low-pressure column. At the same time, nitrogen gas is condensed and liquefied to generate a reflux liquid of both distillation columns. Such a heat exchanger is generally called a condensation evaporator.

As the condensing evaporator, a condensing evaporator using a plate-fin type heat exchanger core is generally used. This plate-fin type heat exchanger core has a large number of heat exchange passages including a condensing passage and an evaporating passage which are adjacent to each other with a partition plate interposed therebetween. Indirect heat exchange with the evaporating fluid (liquefied oxygen) introduced in the above step, condensed fluid is condensed and liquefied and led out below the heat exchanger. It is formed so as to extend downward or downward and upward.

FIG. 8 shows a condensing evaporator (liquid immersion condensing evaporator) using a liquid immersion type plate fin type heat exchanger core utilizing the thermosiphon effect. The condensing evaporator 1 is used by being immersed in liquefied oxygen LO, which is an evaporating fluid stored in a liquid reservoir 2a at the bottom of the low-pressure column 2, and has a heat exchange passage (evaporating passage) on the evaporating fluid (liquefied oxygen LO) side. ) Are open at both ends (upper and lower ends), and the nitrogen gas GN at the top of the high-pressure column 3 is introduced into the condensing passage via the upper header 1a, and the liquefied nitrogen condensed and liquefied in the condensing passage is discharged to the lower portion. Derived from header 1b.

The liquefied oxygen in the evaporating passage undergoes indirect heat exchange with nitrogen gas, which is a condensed fluid in an adjacent condensing passage, whereby a part of the liquefied oxygen evaporates and becomes oxygen gas bubbles.
Ascend the evaporation passage. The liquefied oxygen LO inside and outside the condensing evaporator 1 is generated by the rising force of the oxygen gas and the density difference of the gas-liquid mixture.
A circulating flow is formed due to the thermosiphon effect. Of the oxygen in the gas-liquid mixed state derived from the evaporating passage as an ascending flow, the liquefied oxygen that has not been vaporized returns to the liquid reservoir 2a again, and the vaporized oxygen gas becomes the ascending gas in the low-pressure column 2. The part is extracted from the path 4 as a product.

On the other hand, the nitrogen gas introduced into the condensation passage
The liquid is condensed and liquefied into liquefied nitrogen by indirect heat exchange with the liquefied oxygen, and is discharged from the lower part of the condensing evaporator 1. The discharged liquefied nitrogen is introduced into both distillation columns as a reflux liquid, and a part thereof may be extracted as a liquefied product.

As described above, the liquid immersion type condensation evaporator 1 utilizing the thermosiphon effect is a countercurrent type heat exchanger in which the condensed fluid flows downward and the evaporated fluid flows upward. Since the entire condensing evaporator 1 is used by being immersed in liquefied oxygen, the liquefied oxygen flowing into the evaporation passage from the lower part of the condensing evaporator 1 by the liquefied oxygen liquid head is in a supercooled state.

For this reason, a certain distance is required until the boiling of the liquefied oxygen starts, that is, until the temperature of the liquefied oxygen reaches the saturation temperature by indirect heat exchange with the nitrogen on the condensing side. 20-30 height of heat exchanger
%. That is, the liquid immersion type condensing evaporator 1 does not fully utilize the heat transfer area over the entire height of the heat exchanger.

Further, the boiling point rises due to the liquid head of the liquefied oxygen which is the evaporating fluid, and as shown in FIG. 9, the temperature difference ΔT between oxygen and nitrogen becomes small (temperature pinch), and the set heat transfer In the area, the amount of exchanged heat decreases. Therefore, in order to maintain the exchanged heat, it is necessary to keep the temperature difference ΔT constant. As a method of operating this, usually, the pressure of the condensing-side nitrogen gas corresponding to the rise in the boiling point of liquefied oxygen, that is, the operation of the high-pressure column, The pressure is increased, which in turn leads to an increase in power costs.

Further, in order for the condensing evaporator 1 to function, a large amount of liquefied oxygen must be stored, so that it takes a long time to start up the apparatus, or the amount of liquefied oxygen released when the apparatus is stopped increases, resulting in a reduction in power cost. And a loss of labor costs.

In order to avoid the disadvantage of the liquid immersion type utilizing the thermosiphon effect as described above, a co-current type heat exchanger in which an evaporating fluid is evaporated and vaporized while flowing down from the upper part thereof into an evaporating passage of the heat exchanger. Has been proposed. These are commonly referred to as falling film condensing evaporators.

FIG. 10 shows a falling film condensing evaporator 5 using a plate fin type heat exchanger. The liquefied oxygen LO flowing down from the distillation section 2b of the low-pressure column 2 flows down from the upper part of the condensing evaporator 5 to the evaporation path together with the liquefied oxygen supplied by the pump 6 from the liquid reservoir 2a at the bottom of the low-pressure column. Is indirectly heat-exchanged with nitrogen gas flowing in parallel, and a part of the gas is vaporized. The vaporized oxygen gas is led out into the low-pressure tower 2 from the lower or lower part and the upper part of the evaporating passage, and the liquefied oxygen not vaporized is drawn out from the lower part of the evaporating passage and accumulates in the liquid reservoir 2a at the bottom of the low-pressure tower. It is returned to the upper part of the condensing evaporator 5 by the pump 6 and circulates. Since the nitrogen side is formed in the same manner as described above, the same reference numerals are given and the description is omitted.

As described above, the falling liquid film type condensing evaporator 5 comprises:
Since no liquid head is generated in the liquefied oxygen on the evaporation side, as shown in FIG. 11, the temperature difference ΔT is substantially uniform over the entire height of the heat exchanger, and the liquefied oxygen is evaporated in the entire heat exchanger. Therefore, the heat exchange efficiency is improved, the size and cost of the heat exchanger can be reduced, the power cost can be reduced, and the startup time can be reduced.

Various structures and configurations have been proposed for the falling liquid film type condensing evaporator. For example, Japanese Patent Publication No. Hei 5-31042 and Japanese Patent Publication No. Hei 7-3101 have been proposed.
No. 5, JP-A-8-61868 and the like. In the falling liquid film type condensing evaporator described in these, as a liquid distribution structure for evenly supplying a liquid evaporating fluid to each evaporating passage, a liquid distributing means for performing liquid distribution stepwise is proposed. I have.

For example, Japanese Patent Publication No. 5-31042 discloses a liquid distributing means for distributing liquid in a stepwise manner, comprising an orifice for a preliminary distributing section, and a distributing action of hard way fins (serrated fins). And a precision distribution unit utilizing In Japanese Patent Publication No. Hei 7-31015, a pre-distribution unit using a pipe orifice and a precision distribution unit using the distribution function of hard way fins (serrated fins) are formed. Further, Japanese Unexamined Patent Publication No.
Japanese Patent Application Laid-Open No. 61868 discloses a method in which the aperture ratio of holes of perforated fins used as hard way fins is changed stepwise. Each of the liquid distributing means disclosed in each of these patents is formed integrally with the heat exchanger core by brazing to form a condensing evaporator.

[0016]

As described above, the means for distributing the evaporating fluid of the conventional falling film condensing evaporator is all incorporated in the plate fin heat exchanger, and the liquid distributing means and the heat dissipating means are separated from each other. The exchanger core had an integral structure formed by brazing. As described above, by incorporating all of the liquid distribution means in the heat exchanger core, the structure of the heat exchanger becomes complicated, and there is a problem in that production restrictions are generated and production costs are increased.

Further, when the apparatus is temporarily stopped, the liquid held in the low-pressure column drops and accumulates at the bottom, so that the heat exchanger is immersed and the lower end of the heat exchanger is sealed. Therefore, in the above-mentioned structure in which the hard way fins are provided at the upper part of the evaporating passage, the oxygen gas evaporated in the evaporating passage is hard upper fin, and the lower part is closed by a liquid seal and cannot flow out. The function as a vessel cannot be fulfilled and operation becomes impossible. In such a case, it is necessary to discharge the liquid accumulated in the lower part of the low-pressure column or to provide a heat exchanger having a thermosiphon effect separately from the falling film heat exchanger. In the case of discharging the liquid, there is a loss of cooling of the device, the restarting time is prolonged, which leads to redundant power consumption.In addition, when the thermosiphon type and the falling liquid film type are used in combination, the falling liquid film type However, there is a problem that the characteristics of small temperature difference and effective use of the heat transfer area cannot be fully utilized.

Accordingly, an object of the present invention is to provide a falling liquid film type condensing evaporator that can reduce the manufacturing cost and can also perform heat exchange utilizing the thermosiphon effect.

[0019]

In order to achieve the above object, a falling liquid film type condensing evaporator according to the present invention comprises a plurality of condensing passages and evaporating passages which are alternately adjacently stacked via a vertical partition plate. A gaseous condensed fluid is introduced from above the condensing passage in the plate-fin type heat exchanger core, and a liquid evaporating fluid is allowed to flow down from above the evaporating passage, and both fluids are indirectly connected via the partition plate. In a falling liquid film type condensing evaporator that condenses and liquefies the condensed fluid by heat exchange and evaporates and evaporates the evaporating fluid, the evaporating fluid is uniformly distributed above the heat exchanger core and the evaporating is performed. A liquid distribution unit having a liquid distribution promoting function to be introduced into the passage is provided separately from the heat exchanger core, and is further introduced into the upper part of the evaporation passage from the liquid distribution unit. Evaporating fluid It is characterized in that a precision liquid dispensing means having a liquid distribution promoting function to precisely the liquid distribution in the.

Further, the present invention provides a liquid distributing means in which the portion having the function of promoting liquid distribution is a sintered body made of any one of copper, stainless steel, aluminum alloy, alumina, and ceramics, or having a specific surface area. 500m ² / m
Characterized in that it is formed of ^three or more ordered or irregular packings, or a perforated plate, serrated fins, hard way fins, etc.
It is characterized in that it is larger than the plane dimension of the heat exchanger core, and that the liquid distribution means and the heat exchanger core are integrated by an integrating means.

Further, the precise liquid distributing means comprises a serrated fin or a hard way fin,
It is characterized in that the upper part of the precision liquid distribution means is composed of fins having a function of guiding the evaporated fluid flowing down from the liquid distribution means, and the lower part is composed of hardway fins having a function of promoting liquid distribution.

In particular, the falling film condensing evaporator according to the present invention comprises:
The condensed fluid is nitrogen gas at the top of the high-pressure distillation column of the double distillation column in the air liquefaction separation device, and the evaporating fluid is
It is characterized by liquefied oxygen at the lower part of the low pressure distillation column of the double distillation column in the air liquefaction separation device.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a system diagram showing an example in which a falling film condensing evaporator of the present invention is applied to a double distillation column of an air liquefaction / separation apparatus. The falling liquid film type condensing evaporator (hereinafter, referred to as condensing evaporator) 11 is provided at an intermediate portion between the high pressure column 12 and the low pressure column 13 of the double distillation column. The air serving as the raw material gas is compressed, purified after removing impurities such as carbon dioxide and water, and then purified through the main heat exchanger.
2 is introduced from the path 14 at the lower part. The raw material air introduced into the high-pressure column 12 is separated into nitrogen gas at the top of the column and oxygen-enriched liquefied air at the bottom of the column by a known low-temperature distillation operation in the high-pressure column 12.

The nitrogen gas at the top of the high pressure column 12
And is introduced from the upper header 11a of the condensing evaporator 11 to the upper part of the condensing passage, performs indirect heat exchange with liquefied oxygen flowing in the adjacent evaporating passage in parallel, and is condensed and liquefied to the passage 16 from the lower header 11b. A part thereof is introduced as a reflux liquid into the upper part of the high-pressure column 12, and the remaining part is introduced into the upper part of the low-pressure column 13 through the passage 17 and the valve 18.

On the other hand, liquefied oxygen flowing down the distillation section of the low-pressure column 13 is extracted from the bottom of the low-pressure column 13,
Along with the liquefied oxygen sent by the above, it is separated from the heat exchanger core 20 constituting the condensing evaporator 11 and introduced into a liquid distribution means 21 provided above the core. The liquefied oxygen introduced into the liquid distribution means 21 is subjected to liquid distribution at a portion (bottom part) of the liquid distribution means 21 having substantially the function of promoting liquid distribution.
Precision liquid distributing means 2 provided above heat exchanger core 20
The liquid is further uniformly distributed in 2 and flows down to the upper part of the evaporation passage of the heat exchanger core 20.

A part of the liquefied oxygen flowing down the evaporating passage is vaporized by indirect heat exchange with nitrogen gas flowing concurrently in the adjacent condensing passage, and is discharged from below, below and above the condensing evaporator 11. The liquefied oxygen that has not been evaporated is led out from below the condensing evaporator 11. The oxygen gas derived by evaporating becomes the rising gas of the low-pressure column 13,
A part thereof is extracted from the lower passage 23 of the low-pressure column 13 as product oxygen gas. In addition, the liquefied oxygen derived without being vaporized is collected at the bottom of the low-pressure column 13 and then re-introduced to the liquid distribution means 21 by the pump 19 and circulated.

FIG. 2 is a sectional perspective view of a main part showing a first embodiment of the falling film condensing evaporator of the present invention. The condensing evaporator 30 is connected to a condensing passage 32 through a plurality of partition plates 31.
Fin type heat exchanger core 34 in which a large number of heat exchanger cores 34 are alternately stacked adjacent to each other.
And liquid distributing means 35 provided above.

The upper and lower ends of the condensing passage 32 are sealed by side bars 36, and the sides thereof communicate with the header. The upper and lower ends of the evaporating passage 33 are
Is opened so that liquefied oxygen from the gas flows in and vaporized oxygen gas flows out.

The liquid distributing means 35 is formed as a box-shaped container having an opening at the top by setting up a weir plate 38 around a bottom plate portion 37 which is a part having a liquid distribution accelerating function. The liquefied oxygen flows down from the bottom plate 37 toward the heat exchanger core 34 while being uniformly distributed. The liquefied oxygen that has flowed down from the liquid distribution means 35 is directly or
After hitting 6, it flows down into the evaporation passage 33.

The liquid distribution means 35 and the heat exchanger core 34 are separately manufactured, and a required gap is provided between the lower surface of the liquid distribution means 35 and the upper surface of the heat exchanger core 34. Can be installed. in this way,
By providing the liquid distribution means 35 separated from the heat exchanger core 34 with a gap above the core, this gap is
It can be used as an outlet path for the oxygen gas evaporated and vaporized in the evaporation passage 33. Therefore, even when the condensing evaporator 30 is immersed in liquefied oxygen due to, for example, a temporary stop of the apparatus, the evaporated oxygen gas can be led out from above, similarly to the conventional liquid immersion condensing evaporator. Therefore, liquefied oxygen can be circulated by the thermosiphon effect, and the function as a condensing evaporator can be exhibited.

Thus, even when the apparatus is stopped and restarted, it is not necessary to release the liquefied oxygen at the bottom of the low-pressure column, so that no refrigeration loss occurs and the restart can be performed easily. Reboot time can be reduced. Further, since a conventional low-cost heat exchanger core can be used as the heat exchanger core 34 as it is, the cost of the entire condensing evaporator can be reduced.

The liquid distributing means 35 and the heat exchanger core 34 can be integrally formed by flanges 39a and 39b provided around the liquid distributing means 35, and can be bolted to each other via a suitable spacer between the flanges. The gap can be easily and reliably formed. Further, an integrated structure can be formed by means of integral connection such as bolt connection between flanges, brazing or welding. If no gap is provided, the oxygen gas evaporated and vaporized in the evaporation passage 33 is
Heat exchanger core 34 with liquefied oxygen not vaporized
From below. In this way, by integrating the liquid distribution means 35 and the heat exchanger core 34, the work of incorporating the condensing evaporator 30 into the low-pressure column becomes easy.

As described above, the liquid distribution means 35 is formed by the weir plate 38 for generating a liquid depth for liquid distribution and the bottom plate 37 having a function of accelerating liquid distribution. For the bottom plate portion 37, for example, a sintered body can be used. When a sintered body is used, the liquefied oxygen in the liquid distribution unit 35 is uniformly distributed by passing through the fine holes of the sintered body, and flows down to the evaporation passage 33 of the heat exchanger core 34 below the liquid oxygen. . At this time, the liquefied oxygen can move down the sintered body due to the capillary phenomenon and flow down. However, oxygen gas generated by evaporating and evaporating in the evaporation passage 33 has a large flow resistance of the sintered body. It cannot pass and rise, and there is no fear that the liquid distribution function of the sintered body is hindered by the rising gas. For such a sintered body, an inorganic substance such as alumina or ceramic can be used in addition to metals such as copper, stainless steel, and aluminum alloy.

The portion (bottom plate portion 37) of the liquid distributing means 35 having substantially the liquid distributing function is a regular or irregular filler having the same liquid distributing accelerating function in addition to the sintered body. A perforated plate or the like can be used. The packing material having a large specific surface area is excellent in a liquid distribution promoting function, and a packing material having a specific surface area of 500 m ² / m ³ or more is preferable. As the perforated plate, one kind may be used alone, but one kind or two or more kinds may be used as a multilayer. Furthermore, it can also be configured using serrated fins.

Since these fillers, perforated plates or serrated fins can pass the vaporized vaporized fluid, even when the liquid distribution means 35 and the heat exchanger core 34 are integrated, the thermosiphon can be used. The restart can be easily performed using the effect.

It is preferable that the liquid distribution means 35 has a plane size larger than the plane size of the heat exchanger core 34 in order to capture the liquid flowing down from above. Further, the shape can be the same square planar shape as the heat exchanger core 34, or it can be circular according to the shape of the low pressure column.

Further, as another form having the function of promoting liquid distribution, a hard way fin can be used. FIG. 3 shows a second embodiment of the present invention.
5 shows an example in which a hard way fin 40 is used for a portion (bottom plate portion) 37 having a liquid distribution promoting function. In the following description, the same components as those in the above-described embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted.

The bottom plate portion 37 of the liquid distribution means 35 is formed by alternately stacking a large number of liquid distribution passages 41 and dummy passages 42 through which fluid does not flow. It is formed in the same rectangular shape as the planar shape. The liquid distribution passage 41 has a liquid guide fin 43 having a function of guiding the flow of liquefied oxygen at an upper part, a hard way fin 40 having a liquid distribution promoting function at a middle part, and a lower part at a lower part. And the serrated fins 44 that distribute the liquefied oxygen evenly distributed by the hard way fins 40 more densely and lead out. The liquid guide fin 43 and the serrated fin 4
Reference numeral 4 has a function for ensuring brazing at the time of manufacturing, in addition to a liquid guiding function and a liquid distributing function.

As shown in FIG. 4, the hard way fins 40 are fins arranged so as to impose a maximum flow resistance in the flow direction. The hard way fins 40 are liquefied oxygen flowing downward in the vertical direction. Is a hard way fin 40
As shown by arrows in the figure, the liquid flows down while forming a horizontal zigzag flow perpendicular to the vertical main flow, and the liquid is evenly distributed between the vertical main flow and the surface 40a. . Further, the hard way fins 40 can be formed using appropriate fins selected according to the purpose of use, such as serrated fins and perforated fins.

The liquefied oxygen thus formed and densely distributed in liquid by the middle hard way fins 40 and the lower serrated fins 44 flows out from the lower end of the liquid distribution passage 41 to the liquid distribution means 35, where heat exchange is performed. Passage 3 of vessel core 34
3 is introduced.

The liquid distribution passage 41 can be formed only by the hard way fins 40.
Any one can be used according to the state of use.
Further, a portion of the dummy passage may be formed as the liquid distribution passage 41, and the entire liquid distribution means 35 may be formed by the liquid distribution passage.

FIG. 5 shows a third embodiment of the present invention, in which a precision liquid distribution means 50 having a function of promoting liquid distribution is provided above the evaporating passage 33 of the heat exchanger core 34. ing. This precision liquid distributing means 50 is
It has a function of further promoting the liquid distribution of the liquefied oxygen flowing down from 5, and is formed by serrated fins 51.

A portion (bottom plate portion) of the liquid distribution means 35 having a liquid distribution promoting function, such as a sintered body or a hard way fin.
The liquefied oxygen distributed at 37 and flowing down to the heat exchanger core 34 flows down to the serrated fin 51 provided integrally with the upper part of the evaporating passage 33, and
Due to the liquid distribution promoting function of 1, the liquid is uniformly distributed more precisely and introduced into the evaporation passage 33. Since the serrated fins 51 used here are a kind of fins used in a conventional heat exchanger, the heat exchanger core 34 can be manufactured at low cost in the same manner as in the related art.

FIG. 6 shows a modification of the third embodiment. That is, the precise liquid distribution means 50 using the hard way fins 52 is provided above the evaporating passage 33 of the heat exchanger core 34. Hard way fins 52
It has a liquid distribution function as described above, and can be formed of serrated fins, perforated fins, or the like in the same manner as described above.

FIG. 7 shows still another modification of the third embodiment. That is, the evaporation passage 33 of the heat exchanger core 34
The liquid guide fins 53 having the function of guiding the liquefied oxygen flowing down from the liquid distribution means 35 are provided above the precision liquid distribution means 50 comprising the hard way fins 51 provided above the liquid distribution fins 51. The liquid guide fins 53 not only have a liquid guiding function, but also have a function of ensuring brazing at the upper end of the heat exchanger core 34 when the heat exchanger core 34 is manufactured.

As described above, by providing the precise liquid distribution means 50 above the evaporating passage 33, the liquefied oxygen introduced into the evaporating passage 33 can be made more uniform, and heat exchange with nitrogen gas as a condensed fluid can be achieved. Can be performed more efficiently.

In each of the above embodiments, the case where the falling film type condensing evaporator of the present invention is used as the condensing evaporator provided in the intermediate portion of the double distillation column of the air liquefaction separation apparatus has been described. However, the present invention is not limited to this, and may be used for a condensing evaporator provided at the upper part of a single distillation column, and various condensing evaporators for indirect heat exchange between a condensed fluid and an evaporated fluid.

[0048]

As described above, according to the falling film condensing evaporator of the present invention, the temperature difference between the two fluids can be reduced, the heat exchange efficiency is high, the size can be reduced, and the power cost can be reduced. In addition to having the advantages of a falling liquid film type, such as the liquid distribution means and the heat exchanger core formed separately, the heat exchanger core adopts the same structure as the conventional immersion type. This is advantageous in that the manufacturing cost of the heat exchanger core and the like can be reduced, and that heat exchange utilizing the thermosiphon effect is also possible.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an example in which a falling liquid film condensing evaporator of the present invention is applied to a double distillation column of an air liquefaction / separation apparatus.

FIG. 2 is a sectional perspective view of a main part showing a first embodiment of a falling liquid film type condensation evaporator of the present invention.

FIG. 3 is a sectional perspective view of a main part showing a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a liquid flow in a hard way fin.

FIG. 5 is a sectional perspective view of a main part showing a third embodiment of the present invention.

FIG. 6 is a sectional perspective view of a main part showing a modification of the third embodiment of the present invention.

FIG. 7 is a sectional perspective view of a main part showing still another modified example of the third embodiment of the present invention.

FIG. 8 is a system diagram showing an example of a liquid immersion type condensation evaporator.

FIG. 9 is a view schematically showing a temperature distribution in a liquid immersion type condensation evaporator.

FIG. 10 is a system diagram showing an example of a falling liquid film type condensing evaporator.

FIG. 11 is a diagram schematically showing a temperature distribution in a falling liquid film type condensing evaporator.

[Explanation of symbols]

11: condensation evaporator, 12: high pressure column, 13: low pressure column, 20
... heat exchanger core, 21 ... liquid distribution means, 22 ... precision liquid distribution means, 30 ... condensation evaporator, 31 ... partition plate, 32 ... condensation passage, 33 ... evaporation passage, 34 ... heat exchanger core, 35 ... liquid Distributing means, 36 ... side bar, 37 ... bottom plate, 38 ... weir plate, 39a, 39b ... flange, 40 ... hardway fin, 41 ... liquid distribution passage, 42 ... dummy passage, 43 ... liquid guide fin, 44 ... cell Ted fin, 50: precision liquid distributing means, 51: serrated fin, 52: hard way fin, 53: liquid guide fin

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideyuki Hashimoto 1-16-7 Nishi-Shimbashi, Minato-ku, Tokyo Nippon Sanso Corporation (72) Inventor Shigeru Hayashida 1-16-7, Nishi-Shimbashi, Minato-ku, Tokyo Japan Oxygen Co., Ltd. (72) Inventor Hiroshi Kawakami 1-16-7 Nishi-Shimbashi, Minato-ku, Tokyo Nippon Oxygen Co., Ltd. (72) Inventor Junichi Oya 1-10 Fuso-cho, Amagasaki-shi, Hyogo Sumitomo Precision Industries Inside (72) Inventor Koichiro Kasano 1-10 Fuso-cho, Amagasaki-shi, Hyogo Sumitomo Precision Industries, Ltd. F-term (reference) 4D047 AA08 AB01 AB02 DA06 DA17 DB05

Claims (14)

[Claims] 1. A gaseous condensed fluid is introduced from an upper part of a condensing passage in a plate-fin type heat exchanger core in which a large number of condensing passages and evaporating passages are alternately stacked via a vertical partition plate. A falling liquid that condenses and liquefies the condensed fluid by indirectly exchanging heat between the two fluids through the partition plate while allowing the liquid evaporating fluid to flow down from above the evaporating passage. In the membrane-type condensing evaporator, a liquid distribution unit having a liquid distribution promoting function of uniformly distributing the evaporating fluid and introducing the evaporating fluid into the evaporation passage is provided above the heat exchanger core, A falling liquid film type condensing evaporator, which is provided separately. 2. A gaseous condensed fluid is introduced from above the condensing passage in a plate-fin type heat exchanger core in which a large number of condensing passages and evaporating passages are alternately stacked adjacently via a vertical partition plate. A falling liquid that condenses and liquefies the condensed fluid by indirectly exchanging heat between the two fluids through the partition plate while allowing the liquid evaporating fluid to flow down from above the evaporating passage. In the membrane-type condensing evaporator, a liquid distribution unit having a liquid distribution promoting function of uniformly distributing the evaporating fluid and introducing the evaporating fluid into the evaporation passage is provided above the heat exchanger core, A separate liquid dispensing means having a function of accelerating the liquid distribution for distributing the evaporating fluid introduced from the liquid dispensing means more precisely, provided separately from the evaporating passage; Membrane condensation evaporator. 3. The falling liquid film type condensing evaporator according to claim 1, wherein the portion of the liquid distribution means having the function of promoting liquid distribution is made of a sintered body. 4. The flowing liquid according to claim 3, wherein the sintered body is formed of any one of metals such as copper, stainless steel, and aluminum alloy, and any one of inorganic substances such as alumina and ceramics. Membrane condensation evaporator. 5. The liquid distributing means of the liquid distributing means, which has a function of promoting liquid distribution, comprises a structured packing or a random packing having a specific surface area of 500 m ² / m ³ or more.
Or the falling film condensing evaporator according to item 2. 6. The falling liquid film type condensing evaporator according to claim 1, wherein the portion having the liquid distribution promoting function of the liquid distribution means is formed of a perforated plate. 7. The falling liquid film type condensing evaporator according to claim 1, wherein the portion of the liquid distribution means having a liquid distribution promoting function is formed of a serrated fin. 8. The falling liquid film type condensing evaporator according to claim 1, wherein the portion having the liquid distribution promoting function of the liquid distribution means is made of a hard way fin. 9. The falling liquid film type condensing evaporator according to claim 1, wherein a plane dimension of the liquid distribution means is larger than a plane dimension of the heat exchanger core. 10. The falling liquid film condensing evaporator according to claim 1, wherein said liquid distribution means and said heat exchanger core are integrated by an integrating means. 11. A falling liquid film type condensing evaporator according to claim 2, wherein said precision liquid distribution means comprises a serrated fin. 12. The falling liquid film type condensing evaporator according to claim 2, wherein said precise liquid distributing means comprises a hard way fin. 13. The precision liquid distributing means has an upper part,
The flowing liquid film according to claim 2, wherein the liquid film is formed of fins having a function of guiding an evaporating fluid flowing down from the liquid distribution means, and a lower portion thereof is formed of a hardway fin having a function of promoting liquid distribution. Type condensing evaporator. 14. The condensed fluid is nitrogen gas at the top of a high-pressure distillation column of a double distillation column in an air liquefaction separation device,
3. The falling film condensing evaporator according to claim 1, wherein the evaporating fluid is liquefied oxygen at the lower part of the low pressure distillation column of the double distillation column in the air liquefaction separation device.