JPH0857292A - Packed column - Google Patents

Abstract

PURPOSE: To reduce pressure loss and to widen an operation range by smoothing the flowing-down of a liquid from the corrugated groove of a packing material. CONSTITUTION: This packed column is constituted so as to have such a structure that the lower end 11 of the packing material at the lowerst part of a packed bed constituted at every block is arranged at the position being in contact with the surface 21 of the liquid present in the lower part of the column or at least immersed in the liquid. By this constitution, since the liquid continuously flows out of the lower end part of the packing material at the lowermost part of the packed bed, the packed column reduced in pressure loss and wide in an operation range can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packed column packed with a packing material, and particularly in an air separation device,
The present invention relates to a rectification column for rectifying nitrogen, argon, etc., a water washing cooling tower for cooling air from an air compressor, and a packed tower suitable for an evaporative cooling tower for cooling water of the water washing cooling tower.

[0002]

2. Description of the Related Art A packed column is widely used in the field of chemical engineering such as distillation, rectification and absorption operation. Irregular fillers such as Raschig rings and terraret are widely used as fillers because they are cheap and easy to handle, but as shown in Japanese Utility Model Publication No. 3-128281, There is a problem with the dispersibility of liquids and gases flowing through. On the other hand, the regular packing represented by Melapak (Sulzer), etc.
Since the filler itself has a certain degree of liquid and gas dispersibility, it has recently become popular in various fields.

The present invention is directed to the latter filling material. Examples of this type of device include those described in Japanese Patent Publication No. 57-36009, Japanese Patent Laid-Open No. 61-291017, and the like. These contents are related to the structure of the packing material itself, and as a structure of the packed column packed with the packing material, there is, for example, one described in JP-A-56-155601. However, in these conventional techniques, the structure of the packed column has not been taken into consideration even the flow of the liquid in the packing material.

Regarding the application of the filler in separating air, INDUSTRYAL AND ENGINEERING CHEMISTRY Vo
In l.39, No.6, we are studying nitrogen and oxygen systems.

[0005]

In a packed column containing a packing material, the efficiency of gas-liquid contact between the gas phase and the liquid phase in contact with each other affects the size of the surface area of the packing material. Especially when high separation performance is required, it is effective to have a surface area as large as possible. For this purpose, there is a method of increasing the surface area of the filler per unit volume to increase the total surface area. This method is a method of increasing the surface area per unit volume by reducing the pitch of the thin layer corrugated grooves constituting the filling material.

However, when the pitch of the thin-layer corrugated grooves is reduced, the cross-sectional area of the corrugated grooves is reduced. Since the gas and the liquid rise and fall through the corrugated groove in the filling material, the decrease in the cross-sectional area causes a considerable amount of descent liquid retention. That is, liquid surface tension, viscosity,
Due to the influence of the density and the like, the liquid does not freely flow downward from the corrugated groove at the lower end of the filling material formed for each block.
This phenomenon occurs at the lower end of the filling material, the corrugated grooves are apparently covered with a film of liquid, and the liquid partially drops. There was a problem that the pressure loss of the gas increased due to the breakage of the liquid film, and further, the Rhodig phenomenon was caused to cause unstable operation of the packed column, resulting in a narrow operating range.

An object of the present invention is to provide a packed column capable of reducing pressure loss and widening the operation range.

[0008]

In order to achieve the above object, it is necessary that the liquid flowing down from above in the filler is made to flow smoothly from the lowermost portion of the filler filled in each block, As a means therefor, it is achieved by providing a structure in which the lower end of the lowermost packing material formed for each block in the packed column is in contact with at least the liquid surface of the liquid therebelow.

[0009]

By allowing the lower end of the lowermost packing material in the packed column to contact the liquid surface of the lower liquid, the liquid flowing out of the lowermost packing material is apparently continuous with the lower liquid. The liquid smoothly flows downward due to the continuous action of the liquid. Therefore, the corrugated groove at the bottom of the packing material is not covered with the liquid film, and as a result, the phenomenon of increase in pressure loss is also eliminated, and as a result, a compact packed column having a wide operating range can be provided.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a vertical sectional view of a packed tower of the present invention.
The packed column 100 will be described by taking a rectification column that separates oxygen, nitrogen, argon, etc. from air as an example. In the main rectification column used in the air separation device, an upper column 1 operated at a low pressure, a lower column 2 operated at a high pressure, and liquid oxygen 3 are evaporated to condense nitrogen gas 4 from the upper part of the lower column. It is composed of the main condenser 5. Fillers 6 to 8 are installed in the upper tower 1 in a stacked manner in the axial direction of each block for each block. Each of the fillers, for example, the fillers 6 and 7 is installed in the column axis direction by being shifted by 90 degrees with respect to the thin layer element which is a constituent element of the filler. Further, the thin layer element surface has minute corrugated grooves 9. Each of the fillers 6 to 8 is integrally fixed by a band 10 wound around the outer periphery thereof, and the tip of the band 10 is bent and fixed to the upper tower 1.

The method of installing the lowermost block of the packing material installed in each block, which is a feature of the present invention, is that in the case of this example, the packing material 6 has a lower end 11 of liquid oxygen 3 below it. It is configured to be in contact with the liquid surface 21 or to be buried therein. Of course, the filling material 6 at the bottom is the casing 12 of the upper tower.
Therefore, it is supported by, for example, reinforcement (not shown). As shown in FIG. 1, the liquid 20 flowing down from above the upper tower 1 of the rectification tower flows down in the order of the packing materials 8, 7 and 6, and the rising gas 30 vaporizes the liquid oxygen 3 by the main condenser 5. By doing so, it rises from the space 31 and flows into the filling material 6 from at least the side surface of the filling material 6 of each block and rises.
Gas-liquid contact is performed on the surface of the filling material to separate liquid and gas. Nitrogen gas 4 that exchanged heat with liquid oxygen 3 in the main condenser 5
Becomes liquid nitrogen 40 and is introduced into the lower tower 2 as a reflux liquid.

As described above, in order to improve the separating performance of the packing material, when the cross-sectional area of the corrugated groove of the packing material is made small and the surface area per unit volume is made large, if the amount of liquid from above increases The liquid may not be able to flow smoothly from the lower end of the filling material 6 due to the influence of the surface tension, viscosity, density, and the like.

In the present invention, the lower end 11 of the filling material 6 is in contact with the liquid surface of the liquid oxygen 3 located below the filling material 6 or is buried therein. Therefore, the liquid flowing out from the filling material 6 is continuous. Can flow into the liquid oxygen 3. Therefore, since the corrugated groove below the packing material 6 is apparently not covered with the liquid film, an increase in pressure loss or a loading phenomenon can be prevented, and further, the operation range of the packed column can be widened. can do.

FIG. 2 shows a vertical sectional view of a packed column which is a second embodiment of the present invention. In this embodiment, below the filler 6 in the lowermost block of the filler installed for each block,
A liquid receiving tray 51 having a large number of small holes 50 and an opening at the top is installed. The liquid receiving tray 51 is the lower end 1 of the filling material 6.
It is installed so as to be in contact with 1 or have a gap 52. The liquid 20 from above reaches the lower end 11 of the packed tower 6 and flows into the liquid receiving tray 51. The liquid 20 has at least the liquid surface 22 in the liquid receiving tray 51, and flows out downward through the small holes 50. Therefore, the lower end of the filling material 6 is in contact with the liquid surface of the liquid or is buried therein. As a result, the state of the lower portion of the filling material 6 is the same as that of the first embodiment, and the filling of the lowermost portion is performed. Liquid can be continuously and smoothly discharged from the lower end of the material. Further, compared with the first embodiment, the space can be effectively used, the pressure loss can be prevented from increasing and the loading phenomenon can be prevented by a simple method, and further, the operation range of the packed column can be widened.

In this embodiment, the small hole 5 of the liquid receiving tray 51
When it does not have 0, the liquid 20 overflows the side plate 53 that constitutes the liquid receiving tray 51 and flows out downward. Also in this example,
The same effect as that of the first embodiment can be obtained.

FIG. 3 shows a vertical sectional view of a packed tower which is a third embodiment of the present invention. In this embodiment, the structure of the second embodiment is applied to another place of the packed column 100.
The packing material in the packed tower 100 is stacked for each block in a dozen or more stages to form a continuous packing material, and these are combined to form a packed tower. Therefore, the lowermost packing material configured for each block is present in several places in the packed tower 100. A liquid 20 that has flowed down the packing materials 7 and 6 installed in the packed tower 100 from above the packed tower 100.
Reaches the lower end 11 of the filling material 6 and flows into the liquid receiving tray 51. The liquid 20 is placed on the liquid pan 51 at least on the liquid surface 22.
And flows downward through the small hole 50. Therefore, the lower end of the filling material 6 comes into contact with the liquid surface 22 of the liquid or is buried therein, and flows into the lower filling materials 60 and 70 through the liquid receiving tray 51 and the small holes 50. Therefore, the liquid can be continuously and smoothly discharged from the lower end of the lowermost filler. Therefore, as compared with the first embodiment, the space can be effectively used, the pressure loss can be increased and the loading phenomenon can be prevented by a simple method, and further, the operation range of the packed column can be widened. The liquid tray 51 is
It also acts as a liquid distributor that causes the liquid 20 to be dispersed downward through the small holes 50 and flows out. However, in order to further enhance the distribution ability, a liquid distributor may be provided between the liquid receiving tray 51 and the filling material 60 as needed. Etc. are installed. Further, the housing 12 of this embodiment has a space 31 and has a structure large enough to raise the rising gas 30. Ascending gas 30 from below is space 31
Rises through at least the side surface of the filler 6 of each block, flows into the filler, and rises. In this embodiment, the structure of the second embodiment is applied to another place of the packed column, and the same effect as that of the first and second embodiments can be obtained.

[0017]

According to the present invention, the liquid from above is packed by contacting at least the lower end of the lowermost packing material for each block in the packed tower with the liquid surface of the liquid below. It is possible to smoothly flow out from the corrugated groove of the lowermost filling material. As a result, there is an effect that a packed column with a small pressure loss and a wide operation range can be provided.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a packed tower showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of a packed tower showing a second embodiment of the present invention.

FIG. 3 is a vertical sectional view of a packed tower showing a third embodiment of the present invention.

[Explanation of symbols]

6, 7, 8, 60, 70 ... Filler, 21 ... Liquid level, 11 ...
The lower end of the packing material, 20 ... Liquid, 30 ... Ascending gas, 50 ... Small hole, 51 ... Liquid pan, 100 ... Packing tower.

Claims (3)

[Claims] 1. A plurality of packing materials are installed in multiple stages in the axial direction, each packing material is constituted by a plurality of thin layer products having corrugated grooves arranged in parallel in a packed column, and adjacent thin layer products are A gas in which the corrugated grooves are arranged so as to intersect with each other, and the thin layered article has rows of small holes arranged at intervals so that the liquid flows down from the upper part and rises from the liquid and the lower part. In a gas-liquid contacting packed column for making a direct alternating current contact with each other, the lower end of the filler in the lowermost block of the filler composed of a plurality of blocks is in contact with the liquid surface of the liquid thereunder, or A packed tower characterized by having a structure installed at a position to be buried. 2. A plurality of packing materials are installed in multiple stages in the axial direction, and each packing material is constituted by a plurality of laminating materials having corrugated grooves arranged in parallel in a packed column, and adjacent laminating materials are A gas in which the corrugated grooves are arranged so as to intersect with each other, and the thin layered article has rows of small holes arranged at intervals so that the liquid flows down from the upper part and rises from the liquid and the lower part. In a packed column for gas-liquid contact for making a direct alternating current contact with each other, below the filler of the lowermost block of the filler composed of a plurality of blocks, a liquid tray having a large number of small holes is installed,
The lower end of the filling material contacts the liquid tray, or
A packed tower characterized by having a structure installed with a gap. 3. The packed column according to claim 1, wherein the packed column is a rectification column for air separation.