JP4130852B2 - Liquid collection and distribution device used in packed tower of air liquefaction separation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid collection / distribution device, and more particularly, to a liquid collection / distribution device used in a packed tower filled with a packing material in an air liquefaction / separation device. The present invention relates to a liquid collection and distribution device having a function of uniformly distributing gas.
[0002]
[Prior art]
For example, the rectifying column used in the air liquefaction separation apparatus has a plate column and a packed column, and the packed column can be designed to have a smaller pressure loss than the plate column, so that a large unit of power consumption can be achieved. There is an advantage that high-purity argon can be produced by rectification or reduction. In a gas-liquid contact device using a packing material such as this packed tower, a liquid collection and distribution device is widely used as a means for uniformly distributing the liquid flowing down in the tower (flowing liquid) to the lower packing material. (See Japanese Patent No. 2516680, Japanese Patent Laid-Open No. 6-285323, Japanese Patent Publication No. 7-81781, Japanese Patent Publication No. 61-204001, etc.).
[0003]
[Problems to be solved by the invention]
However, in a rectifying column composed of a conventional liquid collection / distribution device and a packing material, for example, a regular packing material, the composition of the gas rising in the column (rising gas) is inconsistent in the radial direction. If uniform, the rectification efficiency is reduced. For example, as a problem in the packed tower, when some ascending gas does not pass through the packing material and bypasses the vicinity of the tower wall, a predetermined gas purity may not be obtained at the top of the tower. Further, due to the drift of the falling liquid, a place where there is no liquid is generated, and if the gas is bypassed without contacting the liquid, the rectification efficiency is greatly reduced.
[0004]
On the other hand, in the raw material supply stage in the packed tower as described above, a device for sufficiently homogenizing the gas has been proposed (for example, Norton Model 796 distributor / support plate References RFStrigle, Packed Tower Design and Applications, Gulf Publishing) Company, 1994), it becomes non-uniform as the filling height increases. In addition, immediately below the liquid collection and distribution device, the liquid falls on the filler at points or lines, so in the first-stage packed bed, gas-liquid contact is made only at the flow path directly below that point or line. The gas rising to the liquid collection and distribution device becomes non-uniform.
[0005]
Furthermore, when these non-uniformities occur due to sudden causes, such as sudden valve operation or changes in atmospheric pressure, fluctuations in the amount of condensate or pressure fluctuations occur in the condenser, or product gas purity decreases rapidly. This will hinder the supply of product gas. However, conventional fillers and liquid collection and distribution devices have little function to mix and redistribute ascending gas.
[0006]
In contrast to the characteristics of the packed tower as described above, the plate tower adopts a structure in which the rising gas always comes into contact with the liquid, so that the rising gas bypass does not occur as described above, and the gas purity Can be prevented. In addition, since the shelf has a large pressure loss with respect to the filler, nonuniformity in gas composition and velocity is alleviated.
[0007]
Therefore, the present invention provides a liquid collection and distribution device used in a packed tower of an air liquefaction separation apparatus, which can perform an efficient gas-liquid contact operation by combining the characteristics of the packed tower and the plate tower described above. The purpose is to do.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a liquid collection / distribution device according to the present invention is a liquid collection / distribution device used in a packed tower of an air liquefaction / separation apparatus , and is a horizontal rectifying plate that partitions the packed tower up and down. And a liquid spray box penetrating the rectifying plate in the vertical direction, the rectifying plate is provided with a vent for passing an ascending gas, and a falling liquid is provided below the bottom of the liquid spray box. In addition, a spray hole for distributing and spraying the filler layer is provided, and an inflow for holding a falling liquid at a predetermined depth on the rectifying plate and flowing into the liquid spray box at the upper part of the liquid spray box A weir is provided, and the rising gas rising from the lower filler layer is formed so as to rise to the upper filler layer through gas-liquid contact with the falling liquid on the rectifying plate via the ventilation portion. .
[0009]
Furthermore, the liquid collection and distribution device of the present invention is characterized in that the rectifying plate is a perforated plate tray, a bubble bell tray or a valve tray, and the liquid spraying box flows down from the upper filler layer. Is provided with a top plate that prevents the liquid from directly flowing into the liquid spray box, and the top plate is provided in a horizontal direction or at an angle. A communication pipe for making the same is provided between the liquid spray boxes.
[0010]
In addition, a liquid collecting part provided with an ascending passage of the ascending gas and a cover plate for preventing the falling liquid from flowing down in the ascending passage is provided above the rectifying plate, and the liquid collecting part And a liquid downcomer pipe for allowing the falling liquid collected in step (b) to flow into the liquid held on the rectifying plate.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view showing a first embodiment of the liquid collection and distribution device of the present invention. The liquid collection and distribution device 1 includes a horizontal rectifying plate 3 that partitions the packed tower 2 up and down, and a plurality of liquid spraying boxes 4 that penetrate the rectifying plate 3 in the vertical direction. The rectifying plate 3 is formed of a perforated plate tray having a large number of through holes 3a that serve as ventilation portions for passing the rising gas, and is attached to the inner peripheral surface of the packed tower 2 in an airtight manner.
[0013]
The liquid spray box 4 is a rectangular parallelepiped made up of a top plate 4a, a bottom plate 4b, and four side plates 4c. The bottom plate 4b receives the falling liquid flowing into the liquid spray box 4 below. A number of spray holes 5 for distributing and spraying toward the filler layer are provided, and an inflow weir 6 having a predetermined height is provided on the upper part of the pair of short side plates 4c. The inflow weir 6 is provided on the rectifying plate 3 to hold the falling liquid at a predetermined depth, and the falling liquid flowing down from the upper filler layer is predetermined on the rectifying plate 3. A liquid layer having a depth is formed and flows into the liquid spray box 4 over the inflow weir 6. Further, since the top plate 4a covering the upper part of the liquid spraying box 4 is provided, the falling liquid flowing down from the filler layer does not flow directly into the liquid spraying box 4, so that the flow rate and composition of the falling liquid are not good. Even if it is uniform, it is temporarily stored on the rectifying plate 3 and mixed, so that it can flow into each liquid spray box 4 in a uniform state.
[0014]
On the other hand, the rising gas rising from the lower filler layer temporarily stays on the lower surface of the rectifying plate 3 due to the passage resistance of the rectifying plate 3, and then passes through the through hole 3a of the rectifying plate 3. Then, the liquid is ejected into the liquid layer on the rectifying plate 3, where it comes into gas-liquid contact with the falling liquid and then rises to the upper filler layer. Therefore, since the rectifying plate 3 functions as a gas collecting / distributing device, nonuniformity of the composition of the rising gas is alleviated, and the rising gas always passes through the liquid collecting / distributing device 1 in contact with the falling liquid. Therefore, a rapid concentration fluctuation of the rising gas can be suppressed.
[0015]
That is, the liquid collection and distribution device 1 provided in the packed tower 2 has the function of a plate in a normal plate column, so that not only the falling liquid but also the rising gas can be collected and distributed. It is possible to reduce the unevenness of the composition and speed in the rising gas, and an efficient gas-liquid contact operation such as a rectification operation can be performed.
[0016]
Further, since the gas-liquid contact is performed in the liquid collecting / distributing device 1 portion, the filling height of the filler can be lowered. Further, since the L / V in the radial direction of the packed tower 2 is constant and predetermined gas-liquid contact can be reliably performed, composition management on the order of ppm is possible, and a high-purity product can be obtained. .
[0017]
In addition, the liquid collecting / distributing device can be bent, riveted, welded or vacuum brazed, as appropriate, to a metal plate that can be used under extremely low temperature conditions such as aluminum and stainless steel. It can be made by doing. Further, the size and pitch of the through holes provided in the rectifying plate can be arbitrarily set according to the flow rate and pressure of the rising gas, the amount of the falling liquid retained on the rectifying plate, and the like. Further, the rectifying plate is not limited to the perforated plate tray in which the through holes as shown in the above-described embodiment are formed, but the bubble bell tray 7 as shown in FIG. 2 and the valve tray 8 as shown in FIG. 3 are used. The optimum rectifying plate can be selected according to the flow rate of the falling liquid and the rising gas, the ratio thereof, the tower diameter, and the like.
[0018]
On the other hand, the size, shape, and number of installations of the liquid spray box are arbitrary, and may be set so as to be in an optimum state according to the diameter of the packed tower, the flow rate of the falling liquid and the rising gas, and the like. Similarly, the height, width, and shape (for example, a V notch) of the inflow weir can be set according to various conditions such as the flow rate of the falling liquid.
[0019]
FIG. 4 is a perspective view showing a second embodiment of the present invention, in which the substantially entire circumference of the upper edge of the side plate 4c of the liquid spraying box 4 is used as the inflow weir 6, and the width dimension of the inflow weir 6 is enlarged. The top plate 11 covering the upper opening of the liquid spray box 4 is supported in the horizontal direction by the column member 12 provided at the upper edge corner of the side plate 4c. FIG. 5 is a longitudinal sectional view showing a third embodiment of the present invention, in which a top plate 13 covering the upper opening of the liquid spraying box 4 is inclined in the same direction.
[0020]
Thus, the shape, size, support structure, installation angle, etc. of the top plates 4a, 11, 13 are the dimensions of the inflow weir 6 depending on the size (tower diameter) of the liquid collection and distribution device 1 and the amount of falling liquid. It is possible to select appropriately according to. Further, the size of the top plate is increased within a range that does not impede the flow of ascending gas, or the whole or a part of the top plate is tilted and wrapped in the vertical direction so that the falling liquid flows on the rectifying plate 3. The liquid can be prevented from falling directly on the liquid layer portion and generating a wave on the liquid surface of the stored liquid, and a uniform liquid surface suitable for gas-liquid contact can be formed.
[0021]
FIG. 6 is a partially cutaway longitudinal sectional view showing a fourth embodiment of the present invention, in which a communication pipe 21 for making the liquid depth in the plurality of liquid spraying boxes 4 the same is provided in each liquid spraying box 4. It is provided in between. By providing the communication pipe 21 in this way, even when a difference occurs in the amount of liquid flowing into each liquid spray box 4, the liquid depth in each liquid spray box 4 can be kept the same via the communication pipe 21. And the liquid can be uniformly sprayed on the lower filler layer.
[0022]
FIG. 7 is a perspective view showing a fifth embodiment of the present invention, in which there is no filler layer above and a portion for injecting liquid from an inflow pipe 31 connected to the side wall of the tower, for example, the top of the packed tower 2 is shown. 3 shows an example of the shape of a liquid collection and distribution device suitable for installation. In this case, since the falling liquid does not flow from the upper side of the liquid collection and distribution device 1, it is not necessary to provide a top plate in the liquid spraying box 4, and the entire upper edge of the liquid spraying box 4 is used as the inflow weir 6. Can do. Thus, by providing the liquid collection and distribution device 1 having a shelf function at the top of the tower, it is possible to prevent a sudden change in the purity of the gas extracted from the top of the tower.
[0023]
FIG. 8 is a schematic longitudinal sectional view showing a sixth embodiment of the present invention, and shows an example in which a liquid collection device 41 is provided above the liquid collection and distribution device 1. The liquid collection device 41 includes a liquid collection unit 44 including an ascending passage 42 for the ascending gas, and a cover plate 43 for collecting liquid that prevents the falling liquid from flowing into the ascending passage 42. It has a liquid downcomer 45 for letting the falling liquid collected by the liquid collecting part 44 flow down into the liquid held by the rectifying plate 3, and has a well-known structure similar to the conventional liquid collecting and distributing apparatus. Can be used. In this case, the liquid spray box 4 of the liquid collection / distribution device 1 may be the one without the top plate as in the fifth embodiment. This configuration is suitable for portions where liquid enters and exits and where gas enters and exits.
[0024]
【The invention's effect】
As described above, according to the liquid collection and distribution device of the present invention, not only the falling liquid collection and distribution similar to the conventional case, but also the collection and distribution of the rising gas can be performed. The non-uniformity of the speed is alleviated and an efficient gas-liquid contact operation (rectification) can be performed. In addition, since rectification is also performed in the liquid collection and distribution device, it is possible to reduce the packing height of the packing material, and to reduce the size and cost of the packed tower.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a first embodiment of a liquid collection and distribution device of the present invention.
FIG. 2 is an explanatory diagram of a bubble bell tray.
FIG. 3 is an explanatory diagram of a valve tray.
FIG. 4 is a perspective view of a liquid collection and distribution device showing a second embodiment.
FIG. 5 is a longitudinal sectional view of a liquid collection and distribution device showing a third embodiment.
FIG. 6 is a partially cutaway longitudinal sectional view of a liquid collection and distribution device showing a fourth embodiment.
FIG. 7 is a perspective view of a liquid collection and distribution device showing a fifth embodiment.
FIG. 8 is a schematic longitudinal sectional view of a liquid collection and distribution device showing a sixth embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Liquid collection and distribution apparatus, 2 ... Packing tower, 3 ... Rectification plate, 3a ... Through-hole, 4 ... Liquid spraying box, 4a ... Top plate, 4b ... Bottom plate, 4c ... Side plate, 5 ... Spraying hole, 6 ... Inflow weir, 7 ... bubble bell tray, 8 ... valve tray, 11 ... top plate, 12 ... column member, 13 ... top plate, 21 ... communication pipe, 31 ... inflow pipe, 41 ... liquid collecting device, 42 ... ascending passage , 43 ... Cover plate, 44 ... Liquid collection part, 45 ... Liquid downcomer

Claims (5)

A liquid collection and distribution device used in a packed tower of an air liquefaction separation apparatus, comprising: a horizontal rectifying plate for vertically dividing the packed tower; and a liquid spray box penetrating the rectifying plate in the vertical direction. The rectifying plate is provided with a ventilation part for passing ascending gas, and at the bottom part of the liquid spraying box is provided with spraying holes for distributing and spraying the falling liquid to the lower filler layer, and the liquid spraying An inflow weir for holding the falling liquid at a predetermined depth on the rectifying plate and allowing it to flow into the liquid spraying box is provided at the upper part of the box, and the rising gas rising from the lower filler layer is vented A liquid collecting / distributing device, wherein the liquid collecting / distributing device is formed so as to come into gas-liquid contact with the falling liquid on the rectifying plate and to rise to the upper filler layer. 2. The liquid collection and distribution device according to claim 1, wherein the rectifying plate is a perforated plate tray, a bubble bell tray, or a valve tray . The liquid spray box includes a top plate that prevents the falling liquid flowing down from the upper filler layer from directly flowing into the liquid spray box, and the top plate is horizontally or above the liquid spray box. 3. The liquid collection and distribution device according to claim 1, wherein the liquid collection and distribution device is provided so as to be inclined above the liquid spray box . Provided with a plurality of said liquid spraying box, one connecting pipe for the same liquid depth in said plurality of liquid spray box according to claim 1 to 3, characterized in that provided between the liquid spray box one wherein a liquid collecting dispensing apparatus according. Above the rectifying plate, there is provided a liquid collecting part having an ascending passage for the ascending gas and a cover plate for preventing the falling liquid from flowing down into the ascending passage. liquid collecting dispensing apparatus collecting the falling liquid to any one of claims 1 to 4, characterized in that a liquid downcomer to flow down into the liquid held in the rectification plate.

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