CN113941311B - Vertical tray and gas-liquid contact mass transfer equipment with same - Google Patents

Abstract

The utility model provides a vertical tray and gas-liquid contact mass transfer equipment with the vertical tray. The vertical tray includes: -a tray (5), said tray (5) having a plurality of openings (51); and a plurality of mass transfer units (4) disposed on the tray (5) corresponding to the plurality of apertures (51), at least one mass transfer unit (4) including a fixed cover (42) covering the corresponding apertures (51) and a movable portion (43) disposed on the fixed cover (42), wherein a gas-liquid outlet communicating with the corresponding apertures (51) is defined between the movable portion (43) and the fixed cover (42), the movable portion (43) being movably disposed with respect to the fixed cover (42) to be able to adjust a size of the gas-liquid outlet.

Description

Vertical tray and gas-liquid contact mass transfer equipment with same

Technical Field

The utility model relates to petrochemical production equipment, in particular to a vertical tray and gas-liquid contact mass transfer equipment with the vertical tray.

Background

The tower is an important device in the oil refining and chemical production process. The tower type can be divided into a plate tower and a packed tower. The plate tower can be divided into a sieve plate tower, a floating valve tower, a fixed valve tower and the like according to the form of the internal tower tray. In the gas-liquid mass transfer process of the plate column, the liquid phase is a continuous phase, and the gas phase is a dispersed phase. The gas presents a bubbling mass transfer mode in the liquid, and the dispersion degree of the gas in the liquid directly determines the gas-liquid mass transfer efficiency.

Many tray columns today employ vertical jet trays. The vertical jet tray is a tray with a jet hood with a certain gap between the tray and the jet hood and with jet holes on the jet hood. During operation, liquid enters the jet housing from the void below the jet housing by the lifting action of the gas. The liquid entering the jet hood is broken into tiny liquid drops under the action of pulling and tearing of the gas, and the gas-liquid phase is subjected to severe collision in the hood to realize the surface renewal of the liquid and the mass transfer process between the gas phase and the liquid phase. The gas and liquid are then ejected from the hood through the ejection orifice above the hood. Outside the jet hood, the gas and the liquid are separated under the action of gravity, wherein the liquid enters the tray of the lower layer through the downcomer, and the gas enters the tray of the upper layer through the gas lifting holes, so that the mass transfer and the heat transfer processes of the gas and the liquid are realized.

In order to improve the gas-liquid mass transfer efficiency, research on vertical jet trays in the industry has been conducted, for example, chinese patent publication (CN 2367366Y) entitled "radial side-guide jet tray" published in 3/8/2000 proposes that guide plates are installed around the jet hood and on the top cover to prevent liquid back mixing and reduce tray resistance. For another example, chinese patent utility model (CN 2475448U), entitled "solid mass transfer trays", disclosed in 2/6 of 2002, proposes to install three layers of stereoscopically arranged separation plates above the sparging hood to reduce entrainment and improve tray separation efficiency.

The vertical jet trays have the characteristic of changing the traditional liquid phase continuous phase gas phase disperse phase mass transfer mode into a gas phase continuous phase liquid phase disperse phase, and the arrangement of the separation plates also greatly reduces entrainment and improves the gas-liquid mass transfer efficiency. However, these vertical jet trays also have the following problems: the mass transfer effect of the vertical jet tray depends on the gas-liquid ratio, and the vertical jet tray is suitable for gas-liquid mass transfer processes with large gas volume, such as a dry gas amine liquid desulfurization process, a water washing cooling process and the like, and when the gas phase flow is insufficient (lower than 60% of normal load) or the gas volume fluctuates, the vertical jet tray cannot realize normal operation.

Accordingly, there is a need in the industry for a self-balancing vertical tray that can accommodate self-adjusting gas flow without liquid backmixing.

Disclosure of Invention

The utility model aims to provide a vertical tray, which can be operated in a self-balancing mode according to the gas quantity, improves the low-load operation elasticity of the tray and has no liquid back mixing.

The utility model also aims to provide a gas-liquid contact mass transfer device applying the improved vertical tray.

According to an embodiment of the present utility model, there is provided a vertical tray comprising: a tray having a plurality of openings; and a plurality of mass transfer units disposed on the tray corresponding to the plurality of apertures, at least one of the mass transfer units including a fixed cover covering the corresponding aperture and a movable portion disposed on the fixed cover, wherein a gas-liquid outlet communicating with the corresponding aperture is defined between the movable portion and the fixed cover, the movable portion being movably disposed with respect to the fixed cover to enable adjustment of the size of the gas-liquid outlet.

According to the vertical tray provided by the utility model, the movable part is constructed in the form of a floating valve capable of floating flexibly, so that the tray has high operation flexibility and high adaptability. The movable part adjusts the size of a gas-liquid outlet communicated with the opening of the tray plate through movement, thereby adjusting the flux of gas flowing through the tray. When the rising gas phasor is small, the gas rising thrust is insufficient to push the movable part open, the gas-liquid outlet is small, and the gas flux of the tray is small. When the rising gas quantity is larger, the gas pushing force is increased when the gas phase quantity is increased due to the fact that the diameter of the opening is fixed, the movable part is pushed up by the gas, the gas-liquid outlet is increased, and the gas flux of the tray is increased while the gas-liquid mass transfer efficiency is ensured. Thus, liquid jet mass transfer can be formed even under the condition of low gas quantity, and the efficient mass transfer process of the vertical tray under the condition of small gas phase quantity is realized. The vertical tray can effectively improve the low-load operation elasticity of the tray, the movable part can be automatically adjusted according to the air quantity, and liquid back mixing can be prevented. In addition, the vertical tray is convenient to install and detach, improves the working efficiency of the tray, and has remarkable effect.

In some embodiments, the stationary shroud has a slideway, and the movable portion has a leg extending into and movable along the slideway and a stop connected to the leg and disposed in the slideway. This provides a movable portion moving structure of simple structure.

In some embodiments, the ramp has one runner extending in a direction perpendicular to the tray. The support legs of the movable part extend into the sliding groove, so that the movable part can move along the sliding groove.

In some embodiments, the chute has two runners each extending in a direction perpendicular to the tray and in communication with each other, one of the two runners being closer to the tray than the other. The support leg of the movable part extends into one of the sliding grooves and can move along the sliding groove, and the movable part can also move into the other sliding groove to continue moving. The two sliding grooves are arranged in a non-flush, i.e. slightly staggered mode, which is equivalent to increasing the movement stroke of the movable part without arranging a long sliding groove. This configuration makes the slideway layout more compact, saving space.

In some embodiments, the movable portion includes a gas-liquid separation plate coupled to the leg, the gas-liquid separation plate movably covering the stationary cover to define an adjustable sized gas-liquid outlet with the stationary cover. The gas-liquid separation plate can move to adjust the gas flux of the tray and simultaneously block the back mixing of the liquid.

In some embodiments, the tray has a plurality of channel structures corresponding to the plurality of openings, each channel structure having at least one flow channel in communication with the corresponding opening and extending in a direction away from the tray, the stationary shroud is sleeved over the channel structure, and the gas-liquid outlet is in communication with the at least one flow channel, the movable portion being disposed on a side of the stationary shroud away from the channel structure. The channel structure can extend into the fixed cover, and the flow channel can directly guide ascending gas and liquid entering through the holes of the tower plate to the movable part, so that the movable part is pushed to adjust the gas flux.

In some embodiments, a void is formed between the inner peripheral wall of the stationary shroud and the outer peripheral wall of the channel structure in communication with the at least one flow passage. The void space can communicate the flow channels of the channel structure with gas external to the mass transfer unit.

In some embodiments, the vertical tray further comprises: a liquid receiving disc connected to one side of the column plate; and a vertical wall connected to the other side of the tray and defining a downcomer. The liquid receiving tray and the vertical wall can prevent liquid backmixing, and the vertical tray can be directly arranged in the existing gas-liquid contact mass transfer equipment, such as an absorption tower, a cooling tower, a water washing tower and a rectifying tower, without additional modification of the gas-liquid contact mass transfer equipment.

According to another embodiment of the present utility model, there is provided a gas-liquid contact mass transfer device comprising: a tower wall defining an interior space; and a tray connected to the column wall in the interior space; wherein, the tray is the vertical tray.

According to yet another embodiment of the present utility model, there is provided a gas-liquid contact mass transfer device comprising: a tower wall defining an interior space; and a plurality of trays disposed in the interior space in the longitudinal direction of the gas-liquid contacting mass transfer device; wherein each tray of the plurality of trays is the aforementioned vertical tray, the liquid receiving tray of the vertical tray is connected to the column wall, a downcomer is defined between the vertical wall of the vertical tray and the column wall, and the position of the liquid receiving tray of each vertical tray corresponds to the position of the vertical wall of the immediately above one of the vertical trays.

Preferred features of the utility model are described in part below and in part will be apparent from the description.

Drawings

Embodiments of the present disclosure are described in detail below with reference to the attached drawing figures, wherein:

fig. 1 is a partial schematic view of a gas-liquid contact mass transfer device according to an embodiment of the present utility model;

fig. 2 is a schematic cross-sectional view of a gas-liquid contact mass transfer device according to an embodiment of the present utility model;

fig. 3 is a schematic cross-sectional view of a gas-liquid contacting mass transfer device according to another embodiment of the utility model;

fig. 4 is an enlarged view at a of fig. 1, which schematically illustrates the structure of the mass transfer unit;

FIG. 5 is a schematic view of a stationary shroud and a movable portion according to an embodiment of the present utility model; and

fig. 6 is a schematic view of a stationary cover and a movable part according to another embodiment of the present utility model.

Detailed Description

The present utility model will be described in detail with reference to the following detailed description and the accompanying drawings, in order to make the objects, technical solutions and advantages of the present utility model more apparent. The exemplary embodiments of the present utility model and the descriptions thereof are used herein to explain the present utility model, but are not intended to limit the utility model.

Fig. 1 shows a partial schematic view of a gas-liquid contacting mass transfer device according to an embodiment of the present utility model, which may be an absorption tower, a cooling tower, a water scrubber, a rectifying tower, etc. in the petrochemical industry. As shown, the column wall 1 of the gas-liquid contacting mass transfer device can be enclosed in a generally cylindrical shape and define an interior space 11. A support ring 2 (as shown in fig. 2 and 3) may be provided on the inner peripheral wall of the tower wall 1. A plurality of layers of vertical trays 8 are disposed in the interior space 11 in the longitudinal direction of the gas-liquid contacting mass transfer device. In the embodiment shown, these vertical trays 8 are aligned generally in the longitudinal direction. The vertical trays 8 serve to control the gas flux of the gas-liquid contacting mass transfer device.

Fig. 2 shows an embodiment of a vertical tray 8. As shown, the vertical tray 8 includes a tray plate 5 disposed in an interior space 11 of the gas-liquid contacting mass transfer device and a mass transfer unit 4 disposed on the tray plate 5. A plurality of circular openings 51 for ascending gas and liquid to pass through are formed in the tray 5, and a mass transfer unit 4 is correspondingly arranged at each opening 51. One side of the tower plate 5 is connected with the tower wall 1 or is abutted against the support ring 2 through a liquid receiving disc 6, and the other side is provided with a vertical wall 3. The vertical wall 3 is spaced from the column wall 1 and forms a downcomer 31 therebetween. In some embodiments, the circular aperture 51 has a diameter of 10-100mm, such as 20-80mm.

Fig. 3 shows another embodiment of a vertical tray 8. As shown, the vertical tray 8 includes a tray plate 5 disposed in an interior space 11 of the gas-liquid contacting mass transfer device and a mass transfer unit 4 disposed on the tray plate 5. A plurality of rectangular openings 51 for ascending gas and liquid to pass through are formed in the tray 5, and a mass transfer unit 4 is correspondingly arranged at each opening 51. One side of the tower plate 5 is connected with the tower wall 1 or is abutted against the support ring 2 through a liquid receiving disc 6, and the other side is provided with a vertical wall 3. The vertical wall 3 is spaced from the column wall 1 and forms a downcomer 31 therebetween.

Those skilled in the art will appreciate that other shapes of openings may be provided, in addition to the circular openings shown in fig. 2 and the square openings shown in fig. 3, so long as a path is provided for the ascending gas and liquid to pass through. For example, the openings may also be triangular, square, diamond, oval, other polygons, etc.

In some embodiments, tray 5 is assembled from a plurality of tray sections, which may be 3-10, such as 3-8 or 3-6.

In some embodiments, each tray section has a width of 200-500mm, such as 200-400mm. The width of the tower plate section is smaller than the diameter of the manhole so as to facilitate the installation of the tower tray.

In some embodiments, the number of openings or mass transfer units per tray section is from 1 to 100, such as from 1 to 50.

In some embodiments, the placement of the openings in the tray sections may be staggered, parallel, triangular, etc., preferably parallel to each other.

In some embodiments, the vertical walls 3 of a vertical tray 8 are aligned with the liquid receiving tray 6 of the next vertical tray 8 immediately below it, such that liquid falling through the downcomer 31 of a vertical tray 8 can be collected by the liquid receiving tray 6 of the next vertical tray 8 immediately below it, preventing liquid from dripping elsewhere or back mixing.

Fig. 4 schematically shows the structure of the mass transfer unit 4. As shown, mass transfer unit 4 includes a stationary hood 42 that is covered at corresponding openings 51 and a movable portion 43 that is movably mounted to stationary hood 42. The fixed cover 42 is fixed to the opening 51, and an inner hole 421 communicating with the opening 51 is defined in the fixed cover 42, and the ascending gas and liquid can enter the inner hole 421 of the fixed cover 42 after passing through the opening 51, thereby pressing the movable portion 43. The movable portion 43 and the fixed cover 42 define therebetween a gas-liquid outlet through which the ascending gas-liquid passes. When the rising gas phase amount is large, the movable portion 43 can be lifted up, so that the gas-liquid outlet is increased, and the gas flux is increased. When the rising gas phasor is small, the movable part cannot be jacked up or can be jacked up only by a small extent, so that the gas-liquid outlet is reduced, and the gas flux is reduced.

In some embodiments, the height of the stationary shroud 42 is 30-150mm, such as 50-100mm.

In some embodiments, the spacing between the fixed hoods 42 of adjacent two mass transfer units 4 on tray 5 is from 10 to 200mm, such as from 20 to 200mm.

The movable part 43 can be movable in various ways. Fig. 5 shows an embodiment in which the movable part 43 and the fixed cover 42 are mated. As shown, a slide 422 is formed on the fixed cover 42, and the slide 422 is formed of a pair of slide grooves 423 parallel to each other. In the embodiment shown, each runner 423 extends from the top surface of the fixed hood 42 facing the movable portion 43 substantially in a direction perpendicular to the tray 5. The movable portion 43 includes a gas-liquid separation plate 431 and a pair of legs 432 connected to a side of the gas-liquid separation plate 431 facing the fixed hood 42, each leg 432 extending into one of the slide grooves 423, and an end of each leg 432 being provided with a stopper 433. The stopper 433 plays a limiting role and prevents the movable portion 43 from being separated from the chute 423 during movement. Although a pair of runners 423 is shown, those skilled in the art will appreciate that other configurations of runners are possible, such as providing one runner and a corresponding one leg, so long as the path and travel of the movable portion 43 can be defined.

Fig. 6 shows another embodiment in which the movable part 43 and the fixed cover 42 cooperate. As shown, a slide 422 is formed on the fixed cover 42, and the slide 422 is formed of two sets of parallel slide grooves, each set including two slide grooves 424,425 communicating with each other. In the illustrated embodiment, in each set of runners, a first runner 424 extends from a top surface of the stationary shroud 42 facing the movable portion 43 generally in a direction perpendicular to the tray 5, and a second runner 425 extends from a position offset from the top surface of the stationary shroud 42 generally in a direction perpendicular to the tray 5. The second chute 425 is slightly offset from the first chute 424 and closer to tray 5. The movable portion 43 may selectively move along the first chute 424 or along the second chute 425 depending on the actual need of the air flow. Since the two runners 424,425 are in communication with each other, the movable portion 43 can also move continuously from one runner to the other. The staggered arrangement of the two sliding grooves is equivalent to the addition of a stroke for the movable part 43, and meanwhile, a long sliding groove is not required, so that the structure is more compact.

The gas-liquid separation plate 431 is capped in some embodiments with the edges of the gas-liquid separation plate 431 beyond the periphery of the fixed hood 42 such that liquid blocked by the gas-liquid separation plate 431 does not drip back into the fixed hood 42, but falls directly onto the tray 5 and is eventually collected by the liquid receiving tray 6.

With continued reference to fig. 4, in some embodiments, a channel structure 41 is provided on tray 5 corresponding to each opening 51. As shown, the channel structure 41 is connected to the tray 5 at one end and extends away from the tray 5 at the other end, with a retaining cap 42 over the channel structure 41. A flow passage 411 through which the ascending gas-liquid passes is formed in the channel structure 41. The flow passage 411 has one end connected to the periphery of the opening 51 and the other end extending away from the tray 5, and the ascending gas-liquid passes through the opening 51, passes through the flow passage 411, and then enters the fixed cover 42 and presses the movable portion 43. The channel structure 41 is shown as having two elongated flow channels 411, but it will be appreciated by those skilled in the art that the number of flow channels 411 may be provided as desired, such as one, three or more.

In some embodiments, the cross-sectional shape of the channel structure 41 is adapted to the shape of the opening 51 in the tray 5, and may be rectangular, square, circular, oval, diamond, triangular, etc., for example.

In some embodiments, the length of the flow channel 411 may be 10-100mm, such as 10-50mm.

In some embodiments, the retaining cap 42 fits over the channel structure 41 and there is a gap between the inner peripheral wall of the retaining cap 42 and the outer peripheral wall of the channel structure 41, which may be 3-50mm, such as 3-20mm, in width. Furthermore, a gap exists between the stationary hood 42 and the tray 5, which gap may be 3-100mm, for example 3-50mm in height. In this way, the interior of the stationary cover 42 is in communication with the external environment.

In some embodiments, the cross-sectional shape of the retaining cap 42 is adapted to the shape of the channel structure 41, and may be rectangular, square, circular, oval, diamond, triangular, etc., for example.

In some embodiments, the retaining cap 42 is 1-20mm, such as 1-15mm, higher than the channel structure 41.

Examples

Comparative test data for the vertical trays of the present utility model and conventional trays are given below.

In DN600 experiment tower, air and water system are used to make cold mould experiment under normal pressure, and a layer of traditional vertical jet tower plate and a layer of vertical tower plate according to the utility model are arranged in the tower to make comparison experiment.

The parameters of the traditional vertical jet tray structure are as follows:

downcomer area/column cross-sectional area = 13.2%, tray open ratio 10% (weir length 220mm, tray cover diameter 90 mm), jet hood spacing 200mm, plate spacing 500mm, cover height 200mm, effective jet area 100mm.

The structural parameters of the vertical tray according to the utility model are as follows:

downcomer area/column cross-sectional area = 12%, for ease of comparison, the channel structure cross-section was designed to be circular and 50mm in diameter, the spacing between the channel structure and the fixed hood was 15mm, the spacing between the fixed hood and the tray was 30mm, the spacing between the top of the channel structure and the gas-liquid separation plate was 80mm, the spacing between two adjacent mass transfer units on the tray was 200mm, the tray spacing was 500mm, and the in-zone aperture ratio was 20%.

In the experimental process, the gas flow is regulated, and the liquid flow is kept to be 5m ³ And/h, measuring the plate pressure drop of the two trays under different liquid phase loads and the opening kinetic energy factors of the two trays to obtainTo the data shown in the following table:

as can be seen from the above comparative experiments, under the same operating conditions, the pressure drop of the vertical type jet tray of the present utility model is more than 30% lower than that of the conventional vertical type jet tray, and the operating flexibility is improved, and the conventional vertical type jet tray has F0 in the range of 4.5-20Pa during normal operation ^0.5 While outside this range, the vertical trays of the present utility model still perform well.

Compared with the prior art, the vertical tray provided by the utility model has the following advantages:

(1) Compared with the traditional jet-state tray, the vertical tray provided by the utility model has the advantages that the movable part of the vertical tray is self-balanced by virtue of the floating valve of the movable part, and the gas-liquid separation movable part is designed into a flexible floating mode. When the rising gas phasor is small, the gas-liquid rising thrust is insufficient to push the movable part open, and the gas flux is small. When the rising gas quantity is larger, the gas pushing force is increased when the gas phase quantity is increased due to the fact that the diameter of the opening is fixed, the movable part is pushed up by the gas liquid, and the gas flux is increased while the gas liquid mass transfer efficiency is ensured. The utility model realizes the efficient mass transfer process of the vertical jet state mass transfer tray under the condition of small gas phase quantity. The tray has high operation flexibility and high adaptability.

(2) The vertical tray can be applied to newly built gas-liquid contact mass transfer equipment, can also be directly installed in the existing gas-liquid contact mass transfer equipment, does not need additional adaptive transformation, realizes the utilization of the device and reduces the investment.

Various embodiments of the utility model are described herein, but for brevity, description of each embodiment is not exhaustive and identical and similar features or parts between each embodiment may be omitted. The particular features, structures, materials, or characteristics of the embodiments may be combined in any suitable manner in any one or more embodiments or examples herein. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

In this document, the terms "comprises," "comprising," or any variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed.

The exemplary systems and methods of the present utility model have been particularly shown and described with reference to the foregoing embodiments, which are merely examples of the best modes for carrying out the systems and methods. It will be appreciated by those skilled in the art that various changes may be made to the embodiments of the systems and methods described herein in practicing the systems and/or methods without departing from the spirit and scope of the utility model as defined in the following claims. The following claims are intended to define the scope of the systems and methods and systems and methods within the scope of these claims and their equivalents are contemplated. The above description of the present system and method should be understood to include all novel and non-obvious combinations of elements described herein, and claims may be presented in this or a later application to any novel and non-obvious combination of elements. Furthermore, the foregoing embodiments are illustrative, and no single feature or element is essential to all possible combinations that may be claimed in this or a later application.

Claims (7)

1. A vertical tray comprising:

-a tray (5), said tray (5) having a plurality of openings (51); and

a plurality of mass transfer units (4) disposed on the tray (5) in correspondence with the plurality of apertures (51), at least one mass transfer unit (4) comprising a fixed hood (42) covering the respective aperture (51) and a movable portion (43) disposed on the fixed hood (42), wherein a gas-liquid outlet communicating with the respective aperture (51) is defined between the movable portion (43) and the fixed hood (42), the movable portion (43) being movably disposed with respect to the fixed hood (42) to be able to adjust the size of the gas-liquid outlet,

wherein the fixed cover (42) has a slide (422), the movable part (43) has a leg (432) which extends into the slide (422) and can move along the slide (422) and a stopper (433) which is connected to the leg (432) and is provided in the slide (422),

the chute (422) has two runners (424, 425) each extending in a direction perpendicular to the tray (5) and communicating with each other, one of the two runners (424, 425) being closer to the tray (5) than the other.

2. The vertical tray according to claim 1, wherein said movable portion (43) comprises a gas-liquid separation plate (431) connected to said legs (432), said gas-liquid separation plate (431) being movably capped on said fixed cover (42) to define with said fixed cover (42) said gas-liquid outlet of adjustable size.

3. Vertical tray according to claim 1 or 2, characterized in that the deck (5) has a plurality of channel structures (41) corresponding to the plurality of openings (51), each channel structure (41) having at least one flow channel (411) communicating with the corresponding opening (51) and extending in a direction away from the deck (5), the stationary cover (42) being arranged over the channel structure (41) and the gas-liquid outlet communicating with the at least one flow channel (411), the movable part (43) being arranged on the side of the stationary cover (42) facing away from the channel structure (41).

4. A vertical tray according to claim 3, characterized in that a void (7) communicating with said at least one flow channel (411) is formed between the inner peripheral wall of said fixed cover (42) and the outer peripheral wall of said channel structure (41).

5. The vertical tray according to claim 1 or 2, characterized in that the vertical tray (8) further comprises:

a liquid receiving disc (6) connected to one side of the column plate (5); and

a vertical wall (3) connected to the other side of the tray (5) and defining a downcomer (31).

6. A gas-liquid contact mass transfer device comprising:

a tower wall (1) defining an interior space (11); and

-trays connected to the column wall (1) in the inner space (11);

characterized in that the tray is a vertical tray (8) according to any one of claims 1 to 5.

7. A gas-liquid contact mass transfer device comprising:

a tower wall (1) defining an interior space (11); and

a plurality of trays disposed in said interior space (11) in the longitudinal direction of said vapor-liquid contacting mass transfer device;

characterized in that each tray of the plurality of trays is a vertical tray (8) according to claim 5, a liquid receiving tray (6) of the vertical tray (8) is connected to the column wall (1), a downcomer (31) is defined between the vertical wall (3) of the vertical tray (8) and the column wall (1), and the position of the liquid receiving tray (6) of each vertical tray (8) corresponds to the position of the vertical wall (3) of the immediately above vertical tray (8) of the vertical tray (8).