JPH10197169A - Dephlegmator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the treating capacity of gas while avoiding the deterioration of separating performance by a method wherein a distributor, in which a gas supplying passage and a condensed liquid discharging passage are formed so as to be independent from each other, is arranged at the lower side of a gas passage while feed gas is supplied into the gas passage through only the gas supplying passage. SOLUTION: Heat exchange is effected between feed gas and refrigerant in an effective unit 10 to cool the feed gas while high-boiling point constituents in the feed gas become condensed liquid on the ascending way thereof, then, flows down through a gas passage 24. In this case, an exclusive condensed liquid discharging passage 34L, different from a gas supplying passage 34G, is secured in the distributor 12 of a dephlegmators as a processed fluid passage 34, connected to the gas passage 24. Accordingly, the condensed liquid can be discharged surely through a condensed liquid outlet header from the condensed liquid discharging passage 34L even when the supplying amount of feed gas through the gas supplying passage 34G is increased whereby the supplying flow rate of feed gas can be increased while avoiding flooding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dephlegmator (districtor) for performing distillation separation by exchanging heat of a feed gas with a refrigerant.

[0002]

2. Description of the Related Art Conventionally, dephlegmators installed in ethylene plants, gas processing plants, and the like include:
The one shown in FIG. 7 is known. This dephlegmator has an effective portion 80 for effectively exchanging heat between the feed gas and the refrigerant, and a distributor 82 is provided below the effective portion 80. A feed gas inlet header 83 is connected to a lower end of the distributor 82, and a steam outlet header 84 is provided at an upper end of the distributor above the effective section 80. A refrigerant inlet header 86 is connected to an upper side surface of the distributor above the effective portion 80, and a refrigerant outlet header 88 is connected to a lower side surface.

The above-mentioned effective section 80 and distributor 82
, A plurality of gas passages 90 and refrigerant passages 92 as shown in FIG. 8 are provided alternately in the lateral direction. Passage 9
0 and 92 are partitioned by a partition plate 93, and a heat transfer fin 94 also serving as reinforcement is arranged in the passage. That is, this dephlegmator is constituted by a plate-fin type heat exchanger. The distributor 82 includes the valid part 8
This is for uniformly distributing the feed gas into each gas passage 90 just before zero.

A side bar 96 is formed on both sides of the gas passage 90 and on both sides of the refrigerant passage 92 except for a refrigerant inlet opening to which the refrigerant inlet header 86 is connected and a refrigerant outlet opening to which the refrigerant outlet header 88 is connected. The lower end of the refrigerant passage 92 is closed by a bottom bar 98, and the feed gas inlet header 82 is connected to the lower end opening of each gas passage 90 (that is, the feed gas inlet opening).

In this dephlegmator, when the feed gas is distributed upward from the feed gas inlet header 83 into each gas passage 90, and simultaneously, the refrigerant is supplied downward from the feed gas inlet header 83 into each refrigerant passage 92. By performing heat exchange between the feed gas and the refrigerant, the high-boiling components in the feed gas rising in the gas passage 90 are condensed on the way and flow down in the gas passage 90, and the refrigerant inlet header 86 And goes out of the system. On the other hand, the low-boiling components in the feed gas are discharged upward from the steam outlet header 84 without being condensed. That is, the feed gas is separated using the difference in boiling points.

[0006]

In the above dephlegmator, the condensate flows down in the direction opposite to the feed gas rising in the gas passage 90. Here, as described above, since the operating pressure of the distributor 82 is higher than that of the effective section 80, if the supply flow rate of the feed gas is increased, the gas pressure in the distributor 82 becomes extremely high.
A phenomenon (flooding) in which the condensate flowing down to 2 is blown up reversely occurs. When such flooding occurs, the smooth flow of the condensed liquid is hindered, and the high-boiling components may not be sufficiently condensed and separated. From this relationship, conventionally, the supply flow rate of the feed gas has been extremely limited, and it has been difficult to process a large amount of the feed gas with a small dephlegmator.

[0007] In view of such circumstances, an object of the present invention is to provide a dephlegmator capable of improving gas processing capacity while avoiding a decrease in separation performance due to flooding.

[0008]

As means for solving the above-mentioned problems, the present invention provides a plurality of gas passages through which feed gas flows upward and a plurality of refrigerant passages through which refrigerant flows vertically. Are arranged alternately, and the feed gas flowing in each gas passage exchanges heat with the refrigerant flowing in each refrigerant passage, so that a high boiling point component in the feed gas is condensed and flows down in the gas passage. Wherein a gas supply passage for supplying a feed gas to each gas passage and a condensate discharge passage for discharging condensate from each gas passage are formed independently of each other below the gas passage. A viewer is arranged so that feed gas is supplied into the gas passage only through the gas supply passage.

According to this dephlegmator, a condensed liquid discharge passage is secured below each gas passage in addition to a gas supply passage for supplying a feed gas into the gas passage. Even if the feed gas supply flow rate is increased, the condensed liquid can be reliably discharged from the condensed liquid discharge passage by avoiding blowing up of the condensed liquid by the feed gas.

In order to supply the feed gas only from the gas supply passages, for example, the feed gas inlets of the respective gas supply passages are gathered in a specific area and opened in a common feed gas inlet header, and the condensate discharge passages are opened. The condensate outlets may be assembled in a region different from the specific region and opened in a common condensate outlet header.

The opening direction of the feed gas inlet and the condensate outlet is not particularly limited, but if one of the feed gas inlet and the condensate outlet is opened downward and the other is opened laterally, the dephlegmator can be used. The surface area can be used efficiently, and both the feed gas inlet area and the condensate outlet area can be secured large.

[0012]

FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIG.

The dephlegmator shown in FIG. 1 has an effective portion 10 for effectively exchanging heat between a feed gas and a refrigerant, and a distributor 12 is provided below the effective portion 10. A feed gas supply header 14 is connected to a lower end of the distributor 12, a condensate outlet header 16 is connected to a side portion, and a vapor outlet header 1 is connected to an upper end of the effective portion 10.
8 are provided. Further, a refrigerant inlet header 20 is connected to an upper side surface of the effective portion 10, and a refrigerant outlet header 22 is connected to a lower side surface.

FIGS. 2 and 3 (a)
A plurality of gas passages 24 and refrigerant passages 26 as shown in FIG. The passages 24 and 26 are separated from each other by a partition plate 28, and a heat transfer fin 30 also serving as reinforcement is arranged in each passage 24 and 26. Both sides of the gas passage 24 and portions (not shown) of the refrigerant passage 26 except for the refrigerant inlet opening to which the refrigerant inlet header 20 is connected are closed by side bars 32. That is, the effective portion 10 is constituted by a plate-fin type heat exchanger.

The distributor 12 is provided with a plurality of processing fluid passages 34 and a refrigerant discharge passage 36 as shown in FIGS. 2 and 3B, which are alternately arranged in the horizontal direction. The passages 34 and 36 are separated from each other by a partition plate 28 that is continuous from the effective portion 10, and heat transfer fins 30 are arranged in each of the refrigerant passages 36 as described above. It communicates with the refrigerant outlet header 22 on the side. The upper end opening of the processing fluid passage 34 is
The upper end opening of the refrigerant discharge passage 36 matches the lower end opening (feed gas inlet opening) of the gas passage 24 in the effective portion 1.
Distributor 12 is arranged to coincide with the lower end opening of refrigerant passage 26 at zero.

Further, as a feature of the distributor 12, the processing fluid passage 34 is divided into a gas supply passage 34G and a condensate discharge passage 34L by a partition plate 38 dedicated to the distributor parallel to the partition plate 28. The same heat transfer fins 30 as described above are provided in each of the passages 34G and 34L.

Each gas supply passage 34G extends vertically. The upper end opens at a part of the lower end opening of the gas passage 24, and the lower end (feed gas inlet end) opens into the common feed gas inlet header 14. Both sides are closed by sidebars 42 dedicated to distributors.

Each of the condensed liquid discharge passages 34L extends obliquely from the upper end to the side. The upper end is connected to the other portion of the lower end opening of each gas passage 24 (gas supply passage 34).
The upper end of G is open at a portion other than the open portion, and the side end (condensate outlet end) is open in the common condensate outlet header 16.

Next, the operation of the dephlegmator will be described.

When the feed gas is supplied upward from the feed gas inlet header 12, the feed gas is distributed to each gas supply passage 34 G of the distributor 12 and rises in each gas passage 24 of the effective part 10. On the other hand, from the refrigerant inlet header 20 above the dephlegmator, the effective portion 1
The refrigerant is distributed in each of the refrigerant passages 26, and the refrigerant is discharged from the refrigerant outlet header 22 on the side of the distributor 12. Then, the feed gas and the refrigerant exchange heat with each other in the effective portion 10, whereby the feed gas is cooled, and the high-boiling components in the feed gas become condensed liquid during the ascent, and flow down in the gas passage 24. .

Here, conventionally, the gas supply passage of the distributor has been used as the condensate discharge passage as it is.
When the supply flow rate of the feed gas is increased, the upward gas pressure in the gas supply passage is increased, so that the condensate is blown up (flooding). However, in the distributor 12 of the dephlegmator shown in FIGS. 1 to 3, the gas supply passage 34 is connected to the gas supply passage 34 as the processing fluid passage 34 connected to the gas passage 24.
Since a dedicated condensate discharge passage 34L is secured separately from G, even if the feed gas supply flow rate through the gas supply passage 34G is increased, the condensate can be reliably discharged from the condensate discharge passage 34L through the condensate outlet header 16. Can be discharged. That is, according to the dephlegmator, the feed gas supply flow rate can be increased while avoiding flooding. In other words, the entire dephlegmator can be made smaller than before while securing a constant feed gas processing capacity.

FIG. 4 shows the supply flow rate of the feed gas when the feed gas containing the high boiling point component is treated,
5 is a graph showing a relationship between a high boiling point component and an outflow loss at a dephlegmator upper outlet (that is, an upper end opening of a gas passage 24). This outflow loss is obtained by dividing the flow rate at which high-boiling components that should not be discharged from the upper outlet of the dephlegmator are discharged from the upper outlet, by the total steam flow rate (that is, the total discharge flow rate from the upper outlet of the dephlegmator). Therefore, it can be said that the lower the outflow loss, the higher the separation performance.

As shown in the figure, in a region where the feed gas supply flow rate is small, the outflow loss decreases as the feed gas supply flow rate increases, and when the supply flow rate reaches the point P, the outflow loss becomes minimum. Here, since the conventional dephlegmator has a configuration in which flooding is very likely to occur as described above, after the point P, the outflow loss immediately increases due to the occurrence of flooding (curve C1 in the drawing), and the point indicated by the cross mark Then, the dephlegmator hardly functions. On the other hand, in the dephlegmator according to the present invention, by securing the condensed liquid discharge passage 34L,
Even after the point P, flooding hardly occurs for a while (curve C2), and it can function up to the point marked *. That is, according to the dephlegmator according to the present invention, the minimum outflow loss region can be expanded by the width A as compared with the conventional dephlegmator, and the feed gas supply flow rate can be increased by the width A.

FIGS. 5 and 6 show a second embodiment.
Here, the gas supply passage 34G in the distributor 12 extends obliquely downward and leftward in FIGS. 5 and 6 from the lower end of each gas passage 24, and the lower end is opened downward in the left half of FIG. Are connected to a common feed gas inlet header 14. On the other hand, the condensate discharge passage 34L extends obliquely downward to the right in FIGS. 5 and 6 from the lower end of each gas passage 24, and the lower end opens downward in the right half of the drawing.
A common condensate outlet header 16 is connected to these openings. That is, in this embodiment, the feed gas inlet header 14 and the condensed liquid outlet header 16 are arranged side by side at the lower end of the distributor 12 as shown in FIG.

In such a dephlegmator as well, since the condensed liquid discharge passage 34L is secured separately from the gas supply passage 34G, the condensed liquid can be condensed without inconvenience while increasing the feed gas supply flow rate from the feed gas inlet header 14. The liquid can be discharged through the liquid discharge passage 34L. However, compared to the second embodiment, in the first embodiment, the outlet area of the condensed liquid discharge passage 34L and the gas supply passage 34G can be secured larger by effectively utilizing the area of the dephlegmator side. Therefore, the advantage that the flow resistance can be reduced correspondingly is obtained. This advantage can be similarly obtained by, for example, opening the condensate outlet of the condensate discharge passage 34L downward and opening the feed gas inlet of the gas supply passage 34G to the side.

Further, in each of the above embodiments, the feed gas inlets of all the gas supply passages 34G are gathered in a specific area, and the feed gas inlet headers 14 are connected thereto, and the feed gas inlets of all the condensate discharge passages 34L are connected. Are gathered in a specific area and the condensate outlet header 16 is connected to the specific area. However, for example, the feed gas inlets may be dispersed and opened in a plurality of directions, and the feed gas inlet headers may be connected to the respective ports.

[0027]

As described above, according to the present invention, a distributor in which a gas supply passage and a condensate discharge passage are formed independently of each other below a gas passage for feed gas decompression is provided. Since the feed gas is supplied into the gas passage only through the supply passage, the gas treatment capacity can be improved while avoiding a decrease in separation performance due to flooding, and the gas treatment capacity can be kept at a certain level. There is an effect that the size of the entire dephlegmator can be reduced while being held.

Here, the feed gas inlets of the respective gas supply passages are gathered in a specific area and opened in a common feed gas inlet header, and the condensate outlet of each condensate discharge passage is set in a different area from the specific area. When assembled and opened in a common condensate outlet header, each gas passage is passed only through the gas supply passage with a simple configuration in which only a single feed gas inlet header and condensate outlet header are connected. The effect of being able to supply the feed gas to is obtained.

Further, by opening one of the feed gas inlet and the condensate outlet downward and opening the other in the lateral direction, the surface area of the dephlegmator can be effectively used, and the feed gas inlet area and the condensate outlet area can be effectively used. The effect that both can be largely secured is obtained.

[Brief description of the drawings]

FIG. 1 is an overall flowchart of a dephlegmator according to a first embodiment of the present invention.

FIG. 2 is a partially broken perspective view showing a lower portion of the dephlegmator shown in FIG.

3A is a sectional plan view of an effective portion of the dephlegmator shown in FIG. 1, and FIG. 3B is a partial sectional plan view showing an upper end opening of a distributor in the dephlegmator.

4 is a graph showing the relationship between the feed gas supply flow rate and the outflow loss of high boiling point components at the upper outlet of the dephlegmator in the conventional dephlegmator and the dephlegmator shown in FIG.

FIG. 5 is an overall flowchart of a dephlegmator according to a second embodiment of the present invention.

6 is a partially broken perspective view showing a lower portion of the dephlegmator shown in FIG.

FIG. 7 is an overall flowchart of a conventional dephlegmator.

8 is a perspective view showing a lower portion of the dephlegmator shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Effective part 12 Distributor 14 Feed gas inlet header 16 Condensate outlet header 24 Gas passage 26 Refrigerant passage 34 Processing fluid passage 34G Gas supply passage 34L Condensate discharge passage

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenichiro Mitsuhashi 2-3-1, Shinhama, Arai-machi, Takasago-shi, Hyogo Inside Kobe Steel, Ltd. Takasago Works

Claims (3)

[Claims] 1. A plurality of gas passages through which a feed gas flows upward from the bottom and a plurality of refrigerant passages through which a refrigerant flows in an up-down direction are alternately arranged. In a dephlegmator configured so that high-boiling components in the feed gas condense and flow down in the gas passage by exchanging heat with the refrigerant flowing through the gas passage, the feed gas is supplied to each gas passage below the gas passage. And a condensate discharge passage for discharging condensate from each gas passage is arranged independently of each other, and the feed gas is supplied into the gas passage only through the gas supply passage. A dephlegmator characterized in that it is supplied. 2. The dephlegmator according to claim 1, wherein the feed gas inlets of the respective gas supply passages are gathered in a specific area and opened in a common feed gas inlet header, and the condensate outlets of the respective condensate discharge passages are connected. A dephlegmator characterized by being gathered in an area different from the specific area and opened in a common condensate outlet header. 3. The dephlegmator according to claim 2, wherein one of the feed gas inlet and the condensate outlet is opened downward and the other is opened laterally.