JP2787591B2 - Evaporator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to evaporation that exchanges heat between a liquid medium in a first fluid chamber and a fluid in a second fluid chamber to evaporate the liquid medium in the first fluid chamber. About the vessel.

[Conventional technology]

As an example of a conventional evaporator, a condensing evaporator is used which is connected between an upper column and a lower column of a double rectification column of an air liquefaction separator in which the fluid in the second fluid chamber is a condensing nitrogen gas. Will be explained. The condensing evaporator is divided by a number of vertically parallel partition plates, and a so-called plate fin in which two chambers of a first fluid chamber (oxygen chamber) and a second fluid chamber (nitrogen chamber) are alternately stacked adjacently. A so-called heat exchanger is often used.

The oxygen chamber of such a plate fin type condensing evaporator is
A number of vertical evaporation channels are formed by disposing a heat transfer plate in the vertical direction inside, and the upper and lower ends of the evaporation channel are opened, the lower end is used as a liquefied oxygen inlet, and the upper end is formed. The outlet for the mixed flow of oxygen gas and liquefied oxygen. The oxygen chamber is filled with liquefied oxygen by immersing the entire condensing evaporator in a liquid medium (liquefied oxygen) that accumulates in the bottom space of the upper tower. Heat exchange with nitrogen gas introduced from the lower tower, and a part thereof evaporates to become bubbles of oxygen gas, and ascends the evaporation flow path. The liquefied oxygen rises in the oxygen chamber due to the density difference between the gas-liquid mixed phase of the evaporated oxygen gas and the non-evaporated liquefied oxygen and the liquefied oxygen outside the oxygen chamber, and forms a circulating flow inside and outside the condensing evaporator.

On the other hand, in the nitrogen chamber, a vertical heat transfer plate is arranged in the same manner as in the oxygen chamber, and a large number of vertical condensation flow paths are formed in a closed chamber. It is connected to the lower tower via the provided header. Then, nitrogen gas in the upper part of the lower tower is introduced from the upper header into the condensation flow path as a downward flow, and liquefied nitrogen condensed by performing heat exchange with the liquefied oxygen in the condensation flow path is derived from the lower header. ing.

However, such a conventional condensing evaporator is entirely immersed in liquefied oxygen in the upper column bottom space, and is used unless a large amount of liquefied oxygen is stored in the space. Could not function well. For this reason, the start-up time of the apparatus is long, or the amount of liquefied oxygen released at the time of stoppage is increased, resulting in a loss of power cost. By holding more liquefied oxygen,
There are also major security issues in preparing for emergencies.

In addition, since the entire condensing evaporator is immersed in liquefied oxygen, the pressure of liquefied oxygen at the lower part of the condensing evaporator rises due to the liquid depth of the liquefied oxygen, and a boiling point rises. The liquefied oxygen flowing into the evaporation flow path is in a supercooled state. Therefore, in the lower part of the oxygen chamber, liquefied oxygen rising in the evaporation passage must be heated to the boiling start temperature by convective heat transfer having a low heat transfer efficiency, and the heat transfer efficiency of the passage is reduced, and the boiling point is increased. In order to maintain the temperature difference between the oxygen chamber and the nitrogen chamber, the lower tower pressure must be increased to increase the condensation temperature of the nitrogen chamber, so that the power required for compressing the raw material air has been increased. In particular, the required amount of liquefied oxygen stored at the bottom of the upper tower becomes larger as the size of the apparatus becomes larger, and it takes a long time to start.

In order to reduce the influence of the liquid pressure of the liquefied oxygen and the amount of liquid storage, a condensing evaporator as shown in FIG.
No. 267877. In the condensing evaporator incorporated in the double rectification column in FIG. 5, the left half of the figure shows a cross section of the oxygen chamber, and the right half of the figure shows a cross section of the nitrogen chamber.

The condensing evaporator 1 divides the vertical direction in the oxygen chamber 2 by a number of heat transfer plates 3, 3,... For each section, and moves the liquid medium flow paths 4, 4,. A liquid reservoir that is formed in multiple stages and stores liquefied oxygen LO on the inlet 4b side of the liquid medium flow path 4.
Are arranged in upper and lower tiers, and liquefied oxygen LO is supplied from the liquid distribution means 6 to the liquid reservoirs 5, 5,. , 4,..., Liquefied oxygen LO is introduced.

The liquefied oxygen LO introduced into the liquid medium flow path 4 performs heat exchange with the nitrogen gas GN flowing down the adjacent nitrogen chamber 7, and a part of the liquefied oxygen LO evaporates into oxygen gas GO bubbles. This oxygen gas
GO moves up the liquid medium flow path 4 with the liquefied oxygen LO and exits
At the 4a end, it separates from the liquefied oxygen LO and rises upward as indicated by the dashed arrow. On the other hand, liquefied oxygen LO that did not evaporate
The liquid flows down from the outlet 4a of the liquid medium flow path 4 below the condensing evaporator 1 as shown by a solid line arrow, and is lifted to a position above the condensing evaporator 1 by a liquefied oxygen pump 8 or a thermosiphon reboiler. Through the distributing means 6, the liquid reservoir 5
Circulates. Since the liquid depth of the liquefied oxygen LO at this time corresponds to the depth in the liquid reservoir 5, the effect of the liquid pressure can be reduced as compared with a condensing evaporator used by being immersed in the liquefied oxygen.

[Problems to be solved by the invention]

However, in the above-mentioned condensing evaporator 1, for example, the liquefied oxygen LO is completely evaporated in the oxygen chamber 2 and the hydrocarbon such as acetylene is not concentrated and precipitated in the liquid medium flow path 4, for example, the evaporation amount is 6 times or more the evaporation amount. Excess liquefied oxygen LO needs to be introduced into each liquid medium flow path 4. Therefore, the amount of liquefied oxygen flowing down from each liquid medium flow path 4 is large, and a large-capacity liquefied oxygen pump 8
Alternatively, a liquefied oxygen LO had to be circulated by installing a thermosiphon reboiler or the like. For this reason, these equipment costs and the power cost of the liquefied oxygen pump 8 and the like have caused a cost increase. In addition, the connecting portion between the heat transfer plate 3 and the liquid reservoir 5 has a problem in structural strength.

Therefore, an object of the present invention is to provide an evaporator that can make use of the advantages of the liquid circulation type condensing evaporator and can further reduce costs such as equipment costs and operation costs.

[Means for Solving the Problems] In order to achieve the above object, the evaporator of the present invention comprises:
The first fluid chamber and the second fluid chamber are alternately formed by a large number of vertical partition plates, and the evaporator performs heat exchange between the liquid medium in the first fluid chamber and the fluid in the second fluid chamber. Heat transfer plates are arranged in the upper and lower stages in the fluid chamber, a first flow path having an ascending gradient from one side of the evaporator to the other side, and a first flow path of the first flow path from the other side of the evaporator to one side. Forming a second flow path having an ascending gradient in a direction opposite to the gradient, a plurality of liquids communicating with each flow path at the lower end sides of the first flow path and the second flow path, and having an upper part opened; A plurality of reservoirs are provided in upper and lower stages, and a plurality of liquid receivers communicating with the respective channels and having an open upper portion are provided in upper and lower stages on the upper end sides of the two flow paths, and the liquid led out to the liquid receiver from one of the flow path ends is provided. It is characterized in that the medium is supplied to the liquid reservoir in the other flow path.

Further, the evaporator of the present invention is that the first flow path and the second flow path are collectively arranged in a first flow path group and a second flow path group, and the heat transfer plate disposed in the first fluid chamber. At predetermined intervals, a plurality of partitioning rods are arranged in parallel with the heat transfer plate, and the partitioning rods are used to divide the flow path into a flow path block including a plurality of upper and lower flow paths, and each of the flow path groups A liquid reservoir and a liquid receiver are provided for each of the flow path blocks, and a bottom plate of the liquid reservoir and the liquid receiver is connected to an end of the partition bar; A liquid supply pipe is disposed along at least one of the liquid supply pipes, and the liquid supply pipe and each liquid reservoir or liquid receiver are communicated with each other by a liquid medium supply hole provided on a side wall of the liquid reservoir or liquid receiver. It is characterized by.

(Operation)

With the configuration as described above, the liquid medium that is derived from the outlet end and flows down without evaporating in the first flow path is received by the liquid receiver provided at the outlet end of the flow path, and The liquid medium can be supplied to the liquid reservoir, and the liquid medium, which has conventionally been drawn out from the evaporator and flowed downward, can be introduced into the second flow path and used again for evaporation. Also, the liquid medium that has not evaporated in the second flow path is supplied from the liquid receiver in the second flow path to the liquid reservoir in the first flow path, so that the liquid medium is circulated through the first and second flow paths. It is possible to evaporate, and it is possible to reduce the amount of the liquid medium flowing down by leading out the evaporator.

In addition, by forming the first flow path and the second flow path in each group and forming them collectively, the formation of each flow path, the formation of a liquid reservoir and the liquid receiver, and the assembly can be easily performed. Further, by connecting the partition bar to the bottom of the liquid reservoir and the liquid receiver, the structural strength can be improved, and the liquid reservoir and the liquid receiver can be securely attached, and the liquid leakage from the bottom is reduced. be able to.

Then, a liquid supply pipe is provided along the liquid reservoir or the liquid receiver, and the liquid medium supply holes provided on the side walls of the liquid reservoir or the liquid receiver are connected to each other to supply the liquid medium to each liquid reservoir or the liquid receiver. In addition to facilitating the production, the production can be facilitated.

〔Example〕

Although the present invention does not limit the fluid in the second fluid chamber to the condensed nitrogen gas, the present invention will hereinafter be described by condensing the liquid medium evaporating in the second fluid chamber with liquefied oxygen and the second fluid chamber. An example in which the fluid is nitrogen gas will be described in more detail with reference to FIGS. The liquid flow direction is indicated by a solid arrow, and the gas flow direction is indicated by a dashed arrow.

1 to 4, a condensing evaporator 10, which is a kind of evaporator, has a large number of partition plates 1 provided in parallel in a vertical direction.
The number of first fluid chambers (oxygen chambers) 12,12,…
And second fluid chambers (nitrogen chambers) 13, 13,... Are alternately stacked.

In the oxygen chamber 12, heat transfer plates 14, 14,... Are arranged in upper and lower stages, and a large number of liquid medium flow paths 15a, 15b are formed in the vertical direction. The liquid medium flow paths 15a and 15b are formed by a first flow path 15a having a gradient that goes up from one side to the other side of the condensing evaporator 10.
And a second flow path 15b having an ascending gradient in a direction opposite to the gradient of the first flow path 15a from the other side of the condensation evaporator 10 to one side, and the thickness direction of the condensation evaporator 10 On one side (vertical direction in FIG. 2) (lower half in FIG. 2),
In FIG. 1, the first flow paths 15a having an upward slope in FIG. 1 are collectively arranged. On the other side (the upper half in FIG. 2), the second flow paths 15b having an upward slope in FIG. Are located. These liquid medium passages 15a and 15b are usually formed by arranging the corrugated heat transfer fins at an angle, and a part of the liquid medium passages 15a and 15b is transferred at appropriate intervals. Partition bars 16,16, ... slightly thicker than the hot plate 14.
Are arranged.

A plurality of liquid reservoirs 17, 17,... Communicating with the liquid medium flow paths 15a, 15b and liquid receivers 18, 1, are provided at the end of the oxygen chamber 12 thus formed.
8, ... are provided in upper and lower tiers. The liquid reservoir 17 has an opening on one side communicating with the lower end of the gradient of the liquid medium flow paths 15a and 15b, and supplies the liquefied oxygen LO supplied to each liquid reservoir 17 to each liquid medium flow path 15a and 15b. The upper part is opened to release the pressure, and the liquid depth in each liquid reservoir 17 is reduced to reduce the influence of the liquid pressure of the liquefied oxygen LO.

One of the liquid receivers 18 has an opening on one side, the liquid medium flow paths 15a, 15b.
The upper end of each liquid medium flow path 15a, 15b communicates with the upper end of the gradient, and receives liquefied oxygen LO derived from the end of each liquid medium flow path 15a, 15b. Evaporated oxygen gas GO
Is separated from the liquefied oxygen LO and rises above the condensing evaporator 10.

As shown in FIGS. 3 and 4, the liquid reservoir 17 and the liquid receiver 18 are provided with a plurality of upper and lower liquid medium flow paths 15a and 15b as one flow path block. One bottom plate 19 bent and formed to be disposed;
And a wall plate 20 provided so as to surround the three sides. The liquid reservoir 17 and the liquid receiver 18 communicate with each other on the upper surface of the bottom plate 19. By arranging the liquid receiver 18 of the bottom plate 19 higher than the liquid reservoir 17, the liquefied liquid flowing down into the liquid receiver 18 is formed. Oxygen LO
Are made to flow down to the liquid reservoir 17 in the same stage.

The flow path block is defined by the partition rods 16, and connects the liquid reservoir 17 and the bottom plate 19 of the liquid receiver 18 to the ends of the respective partition rods 16. As described above, the partition bar 16 is used to partition the liquid into a flow path block including a plurality of upper and lower flow paths.
By connecting the bottom plate 19 of the liquid receiver 18 to the partition bar 16 thicker than the heat transfer plate 14, the structural strength can be improved, and the adhesion between the flow path end and the bottom plate end can be improved. In addition, it is possible to reduce liquid leakage from the connection portion.

Further, in the present embodiment, both side edges of the side plates 21, 21 arranged on both sides of the condensing evaporator main body in parallel with the partition plate 11 are extended, and the walls on both sides of the liquid reservoir 17 and the liquid receiver 18 are provided. It is a plate.

A liquid supply pipe 22 for supplying liquefied oxygen LO to each liquid reservoir 17
Are provided along one side of the liquid reservoirs 17 provided on the first flow path 15a side, to equalize the amount of liquefied oxygen LO in each of the liquid reservoirs 17, and to carbonize acetylene or the like in the oxygen chamber 12. In order to prevent the concentration of hydrogen, a weir 23 for causing a predetermined amount of liquefied oxygen LO to flow downward is cut out above the liquid receiver 18. The liquid supply pipe 22 and the liquid reservoir 17 communicate with each other by a liquid supply hole 24 formed in a wall plate of the liquid reservoir 17 on the liquid supply pipe 22 side, and the liquefied oxygen LO flowing down the liquid supply pipe 22 is The liquid is supplied into the liquid reservoir 17 from the liquid supply hole 24 of the liquid reservoir 17. Further, the liquid supply hole 24 is provided with a liquid reservoir.
Each of the liquid reservoirs 17 is formed so as to supply a predetermined amount of liquefied oxygen LO. In addition, the liquid supply pipe 22 is installed on the liquid receiver 18 side, and the liquid supply hole 24 is provided.
, The liquefied oxygen LO can be supplied to the liquid receiver 18 and further supplied to the liquid reservoir 17.

Liquefied oxygen introduced into the oxygen chamber 12 thus formed
LO is supplied from the liquid supply pipe 22 to the first flow path 15a through the liquid supply hole 24.
Is supplied to the liquid reservoir 17 on the side, and flows into the first flow path 15a. The liquefied oxygen LO in each first flow path 15a is divided into a heat transfer plate 14 and a partition plate 11
The heat exchange is performed with the nitrogen gas GN flowing in the adjacent nitrogen chamber 13 through the gas chamber, and a part of the gas is evaporated to become bubbles of the oxygen gas GO.
The bubbles of the oxygen gas GO form the liquefied oxygen LO in the first flow path 15a.
At the same time, after rising in the first flow path 15a, it separates from the liquefied oxygen LO at the outlet end and rises upward from the condensing evaporator 10 through the gap between the upper and lower liquid receivers 18,18.

On the other hand, the liquefied oxygen LO that did not evaporate in the first flow path 15a is:
The gas flows out of the outlet end of the first flow path 15a together with the oxygen gas GO, and flows down to the liquid receiver 18 provided at the end of the first flow path 15a. The liquefied oxygen LO flowing down to the liquid receiver 18 of the first flow path 15a
Flows on the bottom plate 19, flows down into the liquid reservoir 17 of the adjacent second channel 15b, and is introduced from the liquid reservoir 17 into the second channel 15b. At this time, a part of the liquefied oxygen LO overflows from the weir 23 and flows down below the lower liquid reservoir 17, the liquid receiver 18, or the condensing evaporator 10.

That is, the liquefied oxygen LO supplied from the liquid supply pipe 22 to the liquid reservoir 17
Is introduced into the first flow path 15a from the liquid reservoir 17 and reaches a liquid receiver 18 while a part thereof evaporates, flows down from the liquid receiver 18 to the liquid reservoir 17 of the second flow path 15b, and flows into the second flow path 15b. And the second flow path 15b
Circulates in a path from the liquid receiver 18 of the
Liquefied oxygen LO is supplied to the liquid reservoir 17 from the liquid supply pipe 22 in an amount corresponding to the amount evaporated in the a and 15b and the amount overflowing from the weir 23.

As described above, the liquefied oxygen LO circulates in the liquid medium flow paths 15a and 15b of the same stage via the liquid receiver 18 and the liquid reservoir 17 while a part of the liquid medium flow path 15a and 15b evaporates. For the condensation evaporator 10
The amount of liquefied oxygen flowing down the space can be greatly reduced. That is, the amount of liquefied oxygen flowing down from the oxygen chamber 12 below the condensing evaporator 10 may be an amount that can prevent hydrocarbons such as acetylene from being concentrated in the liquefied oxygen LO in the oxygen chamber 12; It is sufficient to make the amount slightly larger than the amount of liquefied oxygen evaporated in the condensing evaporator 10, and the liquid medium flow paths 15a, 15
The amount of liquefied oxygen supplied to b can be maintained at about the same level as before, preventing the concentration and precipitation of hydrocarbons such as acetylene, and reducing the amount of liquefied oxygen flowing down the condensing evaporator 10. As a result, the amount of liquefied oxygen to be lifted by a liquefied oxygen pump, a thermosiphon reboiler, or the like can be greatly reduced, so that these devices can be downsized, and the power cost thereof can be reduced in addition to equipment costs. Further, the liquefied oxygen that has flowed down can be led out of the system without being circulated and recovered as liquefied oxygen and / or oxygen gas. The liquefied oxygen pumped by the lifting means can remove hydrocarbons such as acetylene by an adsorber (not shown) on the way.

The inclination angles of the liquid medium flow paths 15a and 15b are appropriately selected depending on the depth of the liquid reservoir 17 to be connected, the length of the liquid medium flow paths 15a and 15b, and the like. Although it is possible to provide the horizontal line 15b, it is more preferable to provide the liquid with a higher gradient than the horizontal line because the bubbles of the oxygen gas GO generated by evaporation will have a floating force.
Since the liquefied oxygen LO is easily sandwiched between the bubbles of the oxygen gas GO and is entrained, the flow can be promoted and the heat transfer coefficient can be increased. That is, as in the above-described embodiment, the liquid medium flow paths 15a and 15b are formed to have an ascending gradient, so that the bubbles of the evaporated oxygen gas GO promote the flow of the liquefied oxygen LO by the buoyancy thereof, and the liquid medium flow paths Since the liquefied oxygen LO flows out and circulates from the outlet ends of 15a and 15b, the liquefied oxygen LO is effectively evaporated, and there is no stagnation of the evaporated oxygen gas GO, so that the heat exchange efficiency of the condensation evaporator 10 can be improved. .

In addition, the upper and lower pitches of the heat transfer plates 14 forming the liquid medium flow paths 15a and 15b are set to a pitch suitable for the oxygen gas GO to accompany the liquefied oxygen LO, and this pitch is too large. Oxygen gas GO slips through, and it becomes difficult to entrain liquefied oxygen LO with bubbles of oxygen gas GO.
LO circulation is reduced, contributing to the concentration of hydrocarbons.

Further, in the present embodiment, the upper and lower liquid reservoirs 17 and the liquid receivers 18 have the same size, and the adjacent liquid reservoirs 17 and the liquid receivers 18 communicate with each other on the bottom plate 19. The size of 18 may be changed in the vertical direction, or the liquid reservoir 17 and the liquid receiver 18 may be formed in independent boxes, and both may be connected by a gutter or a pipe serving as a communication passage for liquid supply.

In addition, the supply of liquefied oxygen LO to each
The liquid supply pipe 22 may be connected to the liquid supply pipe 17, but the liquefied oxygen LO is supplied only to the uppermost liquid reservoir 17 without providing the liquid supply pipe 22, and an overflow pipe or liquid is supplied from the upper liquid reservoir 17 or the liquid receiver 18. It is also possible to adopt a structure in which the liquefied oxygen LO flows down sequentially to the liquid reservoir 17 or the liquid receiver 18 at the lower stage by the overflow weir.
The liquid supply pipe 22 and the liquid reservoir 17 or the liquid
18 may be connected by a gutter or a pipe. Adjustment of the supply amount of the liquefied oxygen LO to each liquid reservoir 17 is performed by providing a flow rate adjusting mechanism, or by adjusting the diameter of the liquid supply hole 24, the position and size of the weir 23, or the diameter and mounting position of the overflow pipe. It can be done by adjusting.

On the other hand, the nitrogen chamber 13 corresponding to the oxygen chamber 12 can be formed in the same manner as that conventionally used in this type of plate-fin type condensing evaporator, and is not within the scope of the present invention. For example, the heat transfer plate 25 is disposed vertically in the nitrogen chamber 13 to form a vertical flow path, and headers (not shown) are connected to the upper and lower sides of the nitrogen chamber 13 so that nitrogen can be transferred from the upper header. Gas can be introduced to draw condensed liquefied nitrogen from the lower header.

As described above, by using the evaporator of the present invention for heat exchange between liquefied oxygen and nitrogen gas in the condensing evaporator of the air liquefaction / separation apparatus, the pressure is released in each of the liquid reservoirs and liquid receivers, so that liquefaction is performed. Compared to a condensing evaporator that is immersed in oxygen, the pressure rise due to the liquefied oxygen liquid depth is reduced, and the influence of the liquefied oxygen liquid depth can be reduced. The difference can be reduced to a minimum, and heat exchange is possible even at a temperature difference of 0.3 ° C., which is significantly reduced as compared with a temperature difference of a conventional evaporator of 1 to 2 ° C. Therefore, the liquefied oxygen and the nitrogen gas can be efficiently heat-exchanged, the heat exchange efficiency of the condensation evaporator is improved, and when the fluid in the second fluid chamber is the condensed nitrogen gas, the condensation temperature is reduced. Since the operating pressure of the lower rectification column can be reduced by lowering the power, the power cost of the entire apparatus can be reduced.

In addition, since there is no influence of the liquid pressure, there is no limitation on the shape of the evaporator in the height direction. By increasing the height, the processing capacity can be greatly increased, and the installation area of the evaporator is limited. In such a case, since the height of the evaporator can be increased and the installation area can be reduced, the evaporator can be easily incorporated into a rectification tower for a large air separation device, and the rectification tower can be manufactured in a vertically integrated structure. . Further, since it is not necessary to immerse the liquid medium in the liquid medium, the operation can be performed with a small amount of the liquid medium, the start-up time can be shortened, and the security problem is reduced.

In addition, the evaporator of the present invention is not limited to evaporation and condensation by heat exchange between liquefied oxygen and nitrogen gas in air liquefaction separation, but also to evaporation of other liquid medium and heat exchange with a fluid (not limited to condensed fluid). It is needless to say that the same operation and effect can be obtained when used, and that it can be applied as an energy-saving evaporator to a small temperature difference evaporator in a process other than the air separation device.

〔The invention's effect〕

As described above, the condensing evaporator of the present invention forms a pair of liquid medium flow paths having an ascending gradient in mutually opposite directions in the first fluid chamber for evaporating the liquid medium, and forms a liquid reservoir on the lower end side of the gradient. A liquid medium is supplied to the second fluid chamber from the second fluid chamber, and heat exchange is performed with the fluid in the second fluid chamber to partially evaporate the liquid medium. Since it is configured to receive the liquid in the liquid receiver and supply it to the liquid reservoir in the other liquid medium flow path, conventionally, it flows down from the liquid medium flow path outlet end to below the evaporator and is circulated by other lifting means. The liquid medium can be circulated by itself in the evaporator. As a result, the amount of the liquid medium flowing down the condensing evaporator can be reduced, the size of the lifting means and the like can be reduced, and the equipment cost and the operating power cost can be significantly reduced. In addition, since the pressure is released at each of the liquid reservoir and the liquid receiving portion, the influence of the liquid depth of the liquid medium is reduced, and the temperature difference between the two fluid chambers can be minimized. Can efficiently exchange heat with
Since the heat exchange efficiency of the evaporator is improved and there is no influence of the liquid pressure, there is no limit on the shape of the evaporator in the height direction,
Processing capacity can be greatly increased. Furthermore, since it is not necessary to immerse the liquid medium in the liquid medium, the operation can be performed with a small amount of the liquid medium, and the start-up time can be reduced.

In addition, by forming the first flow path and the second flow path in each group and forming them collectively, in addition to the formation of each flow path, the formation and assembly of a liquid reservoir and a liquid receiver can be easily performed, and Cost can be reduced.

Furthermore, by connecting the end of the partition bar provided in the first fluid chamber to the bottom of the liquid reservoir and the liquid receiver, the structural strength can be improved, and the liquid reservoir and the liquid receiver can be securely connected. The evaporator can be attached, so that liquid leakage from the connection part can be prevented, and the amount of liquid medium flowing down the evaporator can be further reduced.

In addition, a liquid supply pipe is provided along the liquid reservoir or the liquid receiver, and a liquid medium supply hole provided in a side wall of the liquid reservoir or the liquid receiver communicates with the liquid supply pipe to supply the liquid medium to each liquid reservoir. In addition to making it easier, the evaporator can be easily manufactured as compared with the case in which the liquid supply unit is separately provided. The workability of assembling can also be improved.

[Brief description of the drawings]

1 to 4 show an embodiment of the evaporator according to the present invention. FIG. 1 is a sectional view taken along line II of FIG. Is the first liquid medium flow path II- in FIG.
Fig. 2 is a sectional plan view, Fig. 3 is a partially cut left side view, Fig. 4 is a partially cut right side view, and Fig. 5 is a double rectification column. FIG. 4 is a cross-sectional view showing a conventional condensing evaporator incorporated in the conventional evaporator. 10 ... condensing evaporator, 11 ... partition plate, 12 ... first fluid chamber (oxygen chamber), 13 ... second fluid chamber (nitrogen chamber), 14 ... heat transfer plate,
15a, 15b: Liquid medium flow path, 16: Partition rod, 17: Liquid reservoir, 18
... Liquid receiver, 22 ... Liquid supply pipe, 24 ... Liquid supply hole, GO ... Oxygen gas, LO ... Liquefied oxygen

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-60-17601 (JP, A) JP-A-60-253782 (JP, A) JP-A-63-267877 (JP, A) JP-A-2- 97885 (JP, A) JP-A-2-233985 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F25J 5/00 F28D 9/00-9/04 F28F 3/00 311 F28F 3/08 311

Claims (4)

(57) [Claims] An evaporator in which a first fluid chamber and a second fluid chamber are alternately formed by a number of vertical partition plates, and heat exchange is performed between a liquid medium in the first fluid chamber and a fluid in the second fluid chamber. In the first fluid chamber, heat transfer plates are arranged in upper and lower stages, and a first flow path having an ascending gradient from one side of the evaporator to the other side, and from the other side of the evaporator toward one side. Form a second flow path having a gradient that is the reverse of the gradient of the first flow path, at the lower end of each of the first flow path and the second flow path, communicating with each flow path,
A plurality of liquid reservoirs having an open upper part are provided in upper and lower multi-stages, and a plurality of liquid receivers having an upper part opened are provided in upper and lower multi-stages at the upper ends of both flow paths. An evaporator characterized in that a liquid medium led out from one end to the liquid receiver is supplied to a liquid reservoir in the other flow path. 2. The evaporator according to claim 1, wherein the first flow path and the second flow path are collectively arranged in a first flow path group and a second flow path group. 3. A plurality of partition rods are arranged in parallel with the heat transfer plate at predetermined intervals of the heat transfer plate arranged in the first fluid chamber,
The partition bar divides the flow path into a flow path block including a plurality of upper and lower flow paths, and a liquid reservoir and a liquid receiver are provided for each of the flow path blocks in each of the flow path groups. 3. The evaporator according to claim 2, wherein the bottom plate is connected to an end of the partition bar. 4. A liquid supply pipe is provided along at least one of the liquid reservoirs and the liquid receivers arranged in the upper and lower multi-stages, and the liquid supply pipe and each of the liquid reservoirs or the liquid receivers are connected to the liquid reservoirs. 2. The evaporator according to claim 1, wherein the evaporator communicates with a liquid medium supply hole provided in a side wall of the liquid receiver.