JPS59209606A - Gas-liquid contact apparatus - Google Patents

Abstract

PURPOSE:To contrive to reduce pressure loss in a perforated plate and to enlarge a driving operation range, by utilizing the core metal in a tray tower as a flooding pipe while connecting the flooding pipe provided to the outer peripheral side of the perforated plate and the core metal by a trough. CONSTITUTION:A liquid falling into the core metal 3 mounted in a perforated plate tray tower 1 is flowed onto a perforated plate 8 while flooded over an inlet weir 5 from the outflow port 10 provided to the outer periphery of the core metal 3 and subjected to gas-separation contact with gas rising from the perforations 9 of the perforated plate 8. In the next step, the mass transfer received liquid is flowed into the flooding pipes 2 and again flowed into the core metal 3 through troughs 4. Each trough 4 is attached between the perforated plates 8 and connects each flooding pipe 2 and the core metal 3. Subsequetly, the liquid flowed into the core metal 3 for use with the flooding pipes 2 is again flowed through the next stage perforated plate to be subjected to mass transfer.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a gas-liquid contact device used for operations such as rectification, distillation, and absorption, and particularly relates to a perforated plate tray built into the gas-liquid contact device. It's about configuration.

[Background of the invention]

A gas-liquid contact device composed of perforated plate trays has high rectification performance and has a simple structure, so it is used in a wide range of gas-liquid contact operations. In order to fully utilize the capabilities of the perforated plate tray, it is necessary to optimize the flow state of gas and liquid on the perforated plate. Furthermore, the pressure loss in the perforated plate has a direct effect on the power consumption of the compressor, etc., so it must be kept to a minimum. In order to reduce the pressure loss, there is a method of reducing the amount of rising gas and reducing the gas velocity passing through the holes in the perforated plate, but this method is not a good idea due to conflicts with weaving, partial foaming, and column diameter.

Pressure loss is given by the sum of dry pressure loss, wet pressure loss, and pressure loss due to surface tension. However, if the physical properties of the target fluid and the throughput are the same, the dry pressure loss and the pressure due to surface tension are the same among the above pressure losses. Although the loss is the same, the wet pressure loss differs depending on the structure of the perforated plate. Wet pressure loss is determined by the product of the physical property liquid density and the static liquid depth on the perforated plate.

Since the flow of liquid on a perforated plate with overflow pipes is a natural flow, the static liquid depth is determined by the structure and flow resistance of the outlet weir of the perforated plate. Additionally, flow resistance is determined by the distance that the liquid traverses over the perforated plate. Therefore, no problem is found in small columns with a small throughput, but as the throughput increases and the column diameter becomes large, the flow resistance naturally increases and the static liquid depth increases. In addition, in the structure of a perforated plate plate tower, as a result of various experiments conducted on the flow state of liquid on the perforated plate, the static liquid depth on the perforated plate is h-K (Q
/b) 2/3 ('K: constant, Q: flow rate, b: outlet length increase). Therefore, with perforated plates having the same structure, as the column diameter is gradually increased, the depth of static liquid on the perforated plate becomes larger than necessary, causing an increase in pressure loss. Further, if the static liquid depth becomes large, it may cause weaving and partial foaming, which may lead to a decrease in efficiency. Therefore, if the perforation speed is increased to eliminate these factors, the pressure loss will also increase, creating a vicious cycle, resulting in an increase in power consumption, resulting in an expensive perforated plate tray tower.

In order to minimize the depth of static liquid on the perforated plate, the outlet weir should be made longer according to the above equation. In the conventional technology, in order to lengthen the outlet weir, one method is to use two-way flow and multi-directional flow, but when using multi-directional flow, the effective area for actually performing gas-liquid contact on the perforated plate becomes multi-directional. This is not a good idea as it will cause the increase in column diameter and decrease in efficiency due to uneven flow. Therefore, it is an important challenge to fabricate and operate gas-liquid contact devices that avoid these problems.

1 to 4 show the structure of a conventional perforated plate.

The perforated plate structure is structurally divided into swirl flow and cross flow. Also, depending on the number of channels of liquid flowing on a perforated plate, they are called one-way flow, two-way flow, and four-way flow, and many of these are used in practical use.
Here, we will explain a two-way flow in which there are two liquid flow paths on a perforated plate. In the figure, the liquid falling from the overflow pipe 2 provided in the tray column l seals the overflow pipe 2 with the inlet weir 5, and then flows over the inlet weir 5 onto the perforated plate 8. The inflowing liquid crosses the porous plate 8 from the inlet weir 5 toward the outlet weir 6 while coming into gas-liquid contact with the gas rising through the holes 9 of the porous plate 8. The liquid that has passed through the outlet weir 6 falls again into the next overflow pipe 2 and undergoes operations such as rectification, distillation, and absorption through the same process as above. 3 is the deposit.

As mentioned above, the static liquid depth on the perforated plate is h=K(Q/b)
2', and for the same conditions, the larger the outlet length, the smaller the static liquid depth and the smaller the pressure loss. However, in perforated tray towers with large throughput and large column diameter, the conventional techniques of swirl flow and cross flow have a limit to the length of the outlet weir, and it is unavoidable to adopt a static liquid depth greater than necessary. I don't get it. Furthermore, if multidirectional flow is used to increase the length of the outlet, the proportion of overflow pipes on the perforated plate will increase, resulting in an increase in the column diameter.

[Purpose of the invention]

The present invention was made in view of the above-mentioned problems of the prior art, and its purpose is to reduce pressure loss,
An object of the present invention is to provide a gas-liquid contact device in a perforated plate column having an excellent overflow pipe with a wide range of operation.

[Summary of the invention]

The present invention utilizes a mandrel provided in the column as a part of the overflow pipe, and attaches a gutter between the perforated plates to connect the overflow pipe and the mandrel provided on the outer periphery side. It consists of board shelves.

[Embodiments of the invention]

Hereinafter, one embodiment of the liquid contact device according to the present invention will be described in fifth and sixth embodiments.
This will be explained in detail using figures. In the figure, l denotes a perforated plate tray tower, which has a mandrel 3 in its center and houses a plurality of perforated plates 8. Reference numeral 5 denotes an inlet weir, which serves to liquid-seal the mandrel 3, which also serves as an overflow pipe. Reference numeral 4 connects the overflow pipes 2, which are provided in an appropriate number on the outer periphery of the perforated plate tower l, with the mandrel 3, and 6, 6 installed between the perforated plates 8 and 8 is an outlet weir. , 7 is a partition plate, 9 is a hole in the perforated plate 8, and lO is an outlet.

The liquid that has fallen into the mandrel 3 flows over the inlet weir 5 and onto the perforated plate 8 from several outlets 10 on the outer periphery of the mandrel 3. On the porous plate 8, gas-liquid contact occurs with the gas rising from the holes 9 of the porous plate 8, and mass transfer occurs. The liquid that has crossed the perforated plate 8 flows into the overflow pipe 2 via the outlet weir 6. Furthermore, the overflow pipe 2 and the mandrel 3 are connected through a gutter 4, which allows the water to flow into the mandrel 3 again. The mandrel 3 also serves as an overflow pipe, and the liquid that has flowed into the mandrel 3 flows again into the next-stage perforated plate 8 in the same manner as described above, thereby performing mass transfer.

The configuration and operation described above can provide the following effects. That is, since the length of the exit weir can be structurally increased compared to the conventional next flow and cross flow, the depth of static liquid on the perforated plate can be made as small as possible.

By reducing the depth of the static liquid on the perforated plate, the pressure loss is reduced and the factors of weaving and partial foaming of the perforated plate are also reduced. In other words, the pressure loss is low and the operating range can be widened. In addition, since the thorns are installed between the perforated plates, gas-liquid contact can be carried out effectively without losing the effective area on the perforated plates. On the other hand, as the tower diameter increases, the problem of the strength of the perforated plate becomes a big problem, but since this structure has a mandrel in the center of the tower, the mandrel becomes part of the reinforcement, and the large perforated plate Optical strength can be maintained by simply adding reinforcement in a few places.

Other embodiments of the present invention are shown in FIGS. 7 and 8. In this embodiment, an overflow pipe 2 is arranged along the outer periphery of a perforated tray column 1. According to this embodiment, the length of the outlet weir 6 can be further increased compared to the embodiments shown in FIGS. 5 and 6.
This has the effect that the area of the overflow pipe 2 can also be increased.

In particular, in the perforated plate structure shown in FIG.
are installed along the entire outer periphery, and partition plates 11 are provided according to the number of gutters 4, so that the outlet weir 6 can be sufficiently long, and when the tower diameter is particularly large, or This is particularly useful when the static liquid depth needs to be very small. In the embodiments of the present invention, the number of troughs is three, but the present invention includes variations in the number of troughs.

〔Effect of the invention〕

As described above, according to the present invention, the pressure loss is small, the operating range can be widened, and gas-liquid contact can be carried out effectively.

[Brief explanation of the drawing]

Figures 1.2 and 3 and 4 are explanatory diagrams showing perforated plate structures for swirl flow and cross flow, respectively, which are conventional techniques, and Figure 5.
The figure is a plan view showing one embodiment of the gas-liquid contact device according to the present invention, FIG. 6 is a longitudinal sectional front view thereof, and FIGS. 7 and 8 are plan views showing other embodiments of the gas-liquid contact device according to the present invention. It is a diagram. 1... Perforated plate plate tower, 2... Overflow pipe,
３・・・・・・Single money, ４・・・・・・, ５．・・・
...Inlet weir, 6...Outlet weir, 7...Partition plate, 8...Perforated plate, 9...Perforated plate hole, -2" 1 evil figure 2 figure figure 3Z 迩'5 figure O 6 figure off figure

Claims (1)

[Scope of Claims] 1. It has a plurality of perforated plate shelves inside, and allows liquid to flow down from above and gas to rise from below, thereby bringing the gas and liquid into contact on the perforated plate plates. In a gas-liquid contact device, it is a part of the mandrel overflow pipe in the tray column, and connects the overflow pipe provided on the outer periphery of at least one or more perforated plate with at least one or more mandrel. A gas-liquid contact device characterized in that a trough is attached between perforated plates. 2. The gas-liquid contact device according to claim 1, wherein the overflow pipe is partially installed along the outer periphery of the plate column. 3.r: The gas-liquid contact device according to claim 1, wherein the overflow pipe is installed all around the outer periphery of the plate column.