WO1996028232A1 - Device and method for distributing liquid - Google Patents

Abstract

A liquid distribution device is provided which can improve the dispersion of liquid therein when installed in a filling tower, is of small size and make smaller a filling tower where air and liquid are brought into contact with each other and an air separation device. A liquid receiving plate is provided for receiving liquid flowing down from above for temporarily collecting at the liquid receiving plate. Liquid flowing down from the liquid receiving plate is led to a peripheral edge portion of a circular liquid receiving plate and then to the central portion thereof from the peripheral edge portion via a buffer box so as to be collected at a first liquid distribution box provided at the central portion of the circular liquid plate. A plurality of second liquid distribution boxes each having a number of holes formed in a bottom portion thereof are provided below the first liquid distribution box, whereby liquid collected in the first liquid distribution box is then discharged from those holes formed in the bottom portions of the second liquid distribution boxes, thereby making it possible not only to improve the dispersion of liquid but also to provide a smaller liquid distribution device.

Description

 Specification

Technical Field of the Invention

 The present invention relates to a liquid dispensing apparatus and method for a packed column containing a packing, and more particularly to a liquid dispensing apparatus and method suitable for reducing the column length when applied to a packed column. Background art

 With respect to a conventional liquid distribution device disposed in a packed column of a distillation column, as described in Japanese Patent Application Laid-Open No. 5-184804, an upper packing is provided between packings. A collector that collects the falling liquid, a collecting pipe that collects the liquid collected by the collector, and a number of holes that communicate with the lower end of the collecting pipe and are uniformly arranged on the section of the packed tower. In general, a dispersing tube having a dispersing pipe is provided, and the liquid is uniformly dispersed using the head of the liquid. Alternatively, as disclosed in Japanese Patent Publication No. Hei 6-777683, a device using a substantially rectangular orifice-type trough instead of the dispersion tube is also known. Further, as described in JP-A-6-285532, it has been proposed that a collector for collecting liquid and a liquid distribution box are integrated in order to keep the height of the packed tower low. ing.

 However, the prior art of the above-mentioned liquid distribution apparatus is not sufficient with respect to the structure for reducing the height of the packed tower when installed in the packed tower. Or, even though miniaturization has been achieved, it has not been sufficient for a method of uniformly distributing liquid.

For example, to fully exploit the performance of structured packing in packed towers, It is essential to perform a uniform liquid dispersion. In order to achieve this, depending on the type of packing, a liquid distributing device with several hundred downflow points per square meter of tower cross section has been proposed. However, since it is inevitable that the descending liquid flows in the middle of passing through the packing, the effective gas-liquid contact area per unit volume gradually decreases, and the rectification efficiency decreases. Therefore, in the conventional packed tower, the continuous filling height of the packing for gas-liquid contact is divided into a certain range, and the liquid is separated again between the packing and the collector (liquid collecting device). Liquid dispenser S was installed. On the other hand, the installation of the conventional collector and the liquid distributor S in the packed tower causes a considerable disadvantage to the height of the packed tower. In other words, the space required for the collector and the liquid distribution device had to be secured in the packed tower, which caused the height of the packed tower to be unnecessarily high. In an industrial-scale packed tower, the height of the air gap for installing the collector and the liquid distribution device needs to be about 2 meters.

 A first object of the present invention is to improve the dispersibility of a liquid and to provide a small liquid distribution apparatus and method.

 A second object of the present invention is to provide a liquid distributing apparatus and a method capable of downsizing a packed tower, and further downsizing an air separation device. Disclosure of the invention

The first object is to provide a liquid receiving plate for receiving liquid flowing down from above, guide the liquid flowing down from the liquid receiving plate to a circular liquid receiving plate having a solid plate provided with an opening for gas to rise, The first liquid distribution box is guided to the first liquid distribution box through an opening provided in the liquid receiving tray through which the liquid flows, and a plurality of second liquid distribution boxes having a plurality of holes provided at the bottom below the first liquid distribution box are provided. The opening of the liquid pan, the first liquid distribution box and the liquid inflow part of the second liquid distribution box are achieved by providing By providing a buffer plate made of a perforated plate or a wire mesh, the uniform dispersion of the liquid is improved. Further, preferably, the liquid receiving plate is inclined so that the liquid is guided to the outer periphery of the circular liquid receiving plate, the opening provided in the circular liquid receiving plate is provided at the center, and a plurality of * plates are provided on both sides of Iku Sekiguchi. It is desirable to provide

 The second object is achieved by providing a small liquid distribution device having good liquid dispersibility in a lower column, an upper column, and an argon column of a packed column or a double rectification column of an air separation device.

According to the above configuration, the liquid that has flowed down is once collected by the liquid receiving plate, and then flows down to the circular liquid receiving plate. On the other hand, the liquid receiving plate is inclined so that the liquid is guided to the outer periphery of the liquid receiving plate. Therefore, the liquid forms a gentle liquid gradient while rotating around the relatively long separated periphery of the liquid receiving pan, and then flows into the opening provided at the center of the liquid receiving pan. If a perforated plate or a wire mesh buffer plate is provided in this opening, the liquid flows into the first liquid distribution box at a more uniform flow rate due to the orifice effect. Next, the liquid flowing from the opening holds an appropriate liquid head in the first liquid distribution box. Further, the liquid flows uniformly through holes appropriately provided at the lower end of the first liquid distribution box into a plurality of second liquid distribution boxes, and is provided at the bottom while holding an appropriate liquid head. From the plurality of holes into the packing at a uniform liquid flow rate. If a buffer plate as described above is provided at the inlet of the first liquid distribution box and the second liquid distribution box, a more uniform liquid flow rate can be achieved. On the other hand, in the liquid dispensing apparatus and method according to the present invention, since the liquid receiving plate, the liquid receiving pan, the first liquid distributing type box and the second liquid distributing box are integrated, the height of the liquid distributing apparatus is reduced. It can be lowered. Therefore, the liquid dispensing device S according to the embodiment of the present invention can avoid the disadvantages of the conventional device, improve the liquid dispersibility, and provide a small liquid dispensing device. As a result, it is possible to downsize packed towers with built-in packing. it can.

 The air separation unit rectifies and separates the raw material air using a double rectification column consisting of a high-pressure column and a low-pressure column and an argon column, utilizing the boiling point difference between nitrogen, oxygen and argon. Traditionally, rectification towers used trays, but pressure loss in rectification towers was reduced by replacing them with structured packing (ordered packing), which has a small theoretical pressure loss. It is known that it can be done. However, due to the limitation of the filling height, the collector and the liquid distribution device had to be installed in some places, and the height of the rectification column was unnecessarily increased. By providing the liquid distribution device and the method according to the present invention in a rectification tower of an air separation device, it is possible to downsize the rectification tower or the air separation device. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a structural view showing one embodiment of a liquid distribution device according to the present invention. FIG. 2 is a partial longitudinal sectional view of the liquid distribution device shown in FIG. FIG. 3 is a convenient longitudinal sectional view showing another embodiment of the liquid distribution device according to the present invention. FIG. 4 is a convenient longitudinal sectional view showing another embodiment of the liquid distribution device according to the present invention. FIG. 5 is a convenient longitudinal sectional view showing another embodiment of the liquid distribution device S according to the present invention. FIG. 6 is a structural diagram showing another embodiment of the liquid distribution device according to the present invention. FIG. 7 is a side view showing a second liquid distributor S of the liquid distributor S shown in FIG. FIG. 8 is a plan view showing another example of the second liquid distribution device. FIG. 9 is a structural diagram showing an example of the first liquid distribution device g. FIG. 10 is a flow chart showing one embodiment of an air separation apparatus to which the liquid distribution equipment according to the present invention is applied. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a liquid distribution device according to the present invention. The liquid distribution device 11 is provided in a packed column for gas-liquid contact, that is, in a packed column for performing distillation, absorption, and the like, and is used in a state in which packing materials are installed above and below. The liquid receiving plate 3 (only one side is shown) collects the liquid 1 descending from the upper filling and serves to guide the liquid 1 to the liquid receiving plate 6. The circular liquid receiving tray 6 is provided with two substantially crescent-shaped top plates 4, and the liquid receiving tray 6 is fixed to the inner wall of the packed tower by welding or the like. The liquid 1 guided to the liquid tray 6 flows along the outer peripheral surface of the plate 4 while maintaining a certain liquid head. Into the first rectangular liquid distribution box 7 via. The buffer box 5 is composed of a perforated plate or a wire net, rectifies the turbulence of the inflowing liquid, and flows into the first liquid distribution box 7! : Acts as a kind of resistor to keep constant. The liquid 1 flowing from the buffer box 5 maintains the liquid head, which is the first liquid distribution box 7, and passes through a plurality of holes 8 provided at the bottom to the cross section of the packed tower. The liquid is divided into a plurality of second liquid distribution boxes 9 provided at predetermined intervals. The second liquid distribution box 9 is formed with a number of holes 10 provided below the distribution box, and has a structure capable of performing uniform liquid dispersion while having an appropriate liquid head. I have. On the other hand, the gas 2 rising from the lower packing passes through the gap of the second liquid distribution box 9, passes through the space of the buffet 4, and rises. In the present embodiment, the liquid receiving plate 3 is shown on only one side for convenience, but two liquid receiving plates are required in an actual apparatus. That is, the gas 2 rises through the space 12 between the plate 4 and the liquid receiving plate 3. FIG. 2 shows a partial cross section of the liquid distribution device shown in FIG. The liquid distribution device 11 is provided between two packings 20 which are vertically separated from each other, and the liquid receiving tray 6 is fixed to the tower wall of the packing tower 21 by welding or the like. Ma The liquid receiving plate 3 is fixed to the broken plate 4 by providing a space 12 so that the liquid from the upper filler 20 does not directly pass to the lower filler. The projection area of the liquid receiving plate 3 needs to be slightly larger than the opening area of the plate 4.

Therefore, according to the present embodiment, the liquid 1 that has flowed down is once collected by the liquid receiving plate, and then flows down to the circular liquid receiving tray 3. Next, the liquid 1 forms a gentle liquid gradient while swirling around a relatively long remote periphery, and then flows into an opening provided in the center of the liquid receiving tray. If a buffer box 5 made of a perforated plate or a wire mesh is provided in this opening, the liquid flows into the first liquid distribution box 7 at a uniform flow rate by the orifice effect. The liquid flowing from the buffer box 5 holds an appropriate liquid head in the first liquid distribution box 7. Further, the liquid flows uniformly through holes appropriately provided at the lower end of the first liquid distribution box 7 into the plurality of second liquid distribution boxes 9 and is provided at the bottom while holding an appropriate liquid head. The liquid flows down to the packing 20 from a plurality of holes at a uniform liquid flow rate. On the other hand, the liquid distribution device 11 shown in this embodiment has a liquid receiving plate 3, a liquid receiving plate 6, a first liquid distribution box 7 and a second liquid distribution box 9, so that the liquid distribution The height of the device can be reduced. The height of the liquid distribution device 11 in an industrial scale is about lm. Therefore, the liquid dispensing device 11 of the present embodiment can avoid the drawbacks of the conventional device, improve the dispersibility of the liquid, and provide a small liquid dispensing device. As a result, there is an effect that downsizing of the packed tower containing the packed material can be achieved. FIG. 3 shows another embodiment of the present invention. The description of the same reference numerals as in FIG. 2 is omitted. In the present embodiment, the liquid 1 flowing down from the filler 20 is collected on the inclined liquid receiving plate 3, and most of the liquid 1 flows along the inclined plate 3, and once on the outer periphery of the liquid receiving plate 6. Collected. Thereafter, the liquid 1 flows along the * plate 4 along the relatively long remote periphery of the liquid receiving pan 6. Because this distance exists, to the liquid The head becomes a gorgeous one, and flows into the first liquid distribution box 7 through a rectangular loose mouth box 5 formed of a buffer plate provided at the center of the liquid receiving pan 6. The filter box 5 is a kind of resistor for rectifying the turbulence of the liquid flowing in and keeping the flow rate of the liquid flowing into the first liquid distribution box 7 constant. In the case where the inner diameter of the packed tower is large, the buffer box 5 having a plurality of buffer towers is more uniform in the head of the first liquid distribution box.

 Therefore, according to the present embodiment, in addition to the above-described effects, the liquid can be swirled over a longer distance on the liquid receiving tray, so that the liquid in the first liquid distribution box and the second liquid distribution box can be moved. This has the effect of making the liquid uniform, and has the effect of further improving the dispersibility of the liquid.

 FIG. 4 shows another embodiment of the present invention. The description of the same reference numerals as in FIG. 2 is omitted. In the present embodiment, the liquid 1 flowing down from the filling 20 is collected by the inclined liquid receiving plate 3, and the liquid 1 flows along the swash plate 3, and is collected by the liquid receiving plate 6. The liquid 1 is collected on the outer periphery, and flows along the outer periphery 4 of the liquid pan 6 over a relatively long distance. Therefore, in the present embodiment, the liquid 1 flowing down from the packing 20 directly flows into the buffer box 5 and does not disturb the liquid head in the first liquid distribution box 7. According to this embodiment, in addition to the above-described effects, the liquid heads of the first liquid distribution box and the second liquid distribution box can be made more uniform, and the dispersibility of the liquid is further improved. There is an effect that can be done.

FIG. 5 shows another embodiment of the present invention. The description of the same reference numerals as in FIG. 4 is omitted. In this embodiment, first and second liquid distribution boxes 7 and 9 are provided with buffer plates 30 and 31 made of a perforated plate or a wire mesh at portions where the liquid flows, respectively. The buffer plates 30 and 31 have the same operation as the above-described buffer box 5, that is, have the function of making the flow rate of the liquid uniform by the orifice action. The liquid 1 flowing from the shock absorber 5 is rectified by the buffer plate 30 and Keep the liquid head in liquid distribution box 7 in 1 constant. Next, the liquid flowing down from the hole provided in the first liquid distribution box 7 is further rectified by the cladding board 31 so that the liquid head of the second liquid distribution box 9 is kept constant. Therefore, according to the present embodiment, in addition to the above effects, the effect that the liquid head of the second liquid distribution box can be maintained more evenly, and the effect that the liquid separation property can be further improved can be improved. There is.

 FIG. 6 shows another embodiment of the liquid distribution device according to the present invention. The liquid dispensing apparatus described so far has a structure suitable for a case where the liquid amount is relatively large, but in the case of the present embodiment, it is particularly suitable for a case where the liquid amount is small. That is, when the amount of the liquid is small, the liquid head held on the liquid receiving tray 6 is small, and the disturbance of the liquid is small. For this reason, the liquid head required for the second liquid distribution box described so far is not necessary, and a plurality of tubes 40 can be formed only by the liquid head of the first liquid distribution box 7. The liquid can be distributed uniformly by the large number of holes 10 provided in the holes. The description of the same reference numerals as in FIG. 1 is omitted. Therefore, according to the present embodiment, there is an effect of improving the dispersibility of the liquid with a simple structure, and the height of the liquid distribution device can be further reduced. As a result, there is an effect that downsizing of the packed tower using the packed material can be achieved.

7 and 8 show an embodiment of the liquid distribution box. FIG. 7 is a convenient side view of the first liquid distribution box 7 and the second liquid distribution box 41, and FIG. 8 is a convenient plan view seen from below, from the side where the liquid flows down. In the present embodiment, the second liquid distribution box has an annular shape, and a number of holes are provided at the bottom of the second liquid distribution box 50. The first liquid distribution box is provided with a hole 8 at the bottom as in the previous embodiments. The liquid flow method is the same, but it is structurally possible to provide a large number of holes 10 where the diameter of the packing is large. This means that the density of the falling point per cross-sectional area of the packing can be made uniform, which is advantageous for fully exploiting the performance of the packing. Therefore, according to the present embodiment, In addition to the above effects, there is an effect that the height of the liquid distribution device can be reduced. Although not shown, the configuration of the liquid receiving plate, the liquid receiving plate, and the like can be combined with those of the embodiment of the present invention.

 FIG. 9 shows another embodiment of the liquid distribution box of the present invention. The second liquid distribution box is a rectangle having a large number of holes 10, while the first liquid distribution box 60 is formed of an annular liquid distribution box having two openings. In the case of this embodiment, the volume can be made larger than that of the rectangular first liquid distribution box. That is, in the liquid distribution device S having the same liquid amount, the height a of the first liquid distribution box can be reduced. Further, structurally, the liquid from the first liquid distribution box 60 can flow down not only in the center of the second liquid distribution box 9 but also outside. Therefore, according to the present embodiment, it is possible to provide a liquid dispensing device having an effect of maintaining the liquid head of the second liquid distribution box more favorably and a lower height. Although not shown in the drawings, the same configurations as those of the embodiment of the present invention can be combined for the configuration of the liquid receiving plate, the liquid receiving plate, and the like.

FIG. 10 shows an embodiment in which the liquid distribution device according to the present invention is applied to an air separation device. A typical example of an air separation system is a three-column distillation system consisting of a low-pressure column, a high-pressure column, and a crude argon column. The compressed, purified and cooled raw material air 43 is introduced into the bottom of the high-pressure tower 22 located at the bottom of the double sheathed tower. The gas that has risen in the high-pressure column 22 is condensed in the heat exchanger 23 and becomes a reflux liquid in the column. Liquid nitrogen 46 from the top, impure liquid nitrogen 45 from the middle stage, and oxygen-rich liquid air 44 from the bottom are sent to the upper low-pressure column 24 via a subcooler provided separately. A part of the liquid air is branched on the way from 47 and sent through 50 to the condenser 26 of the crude argon column. Liquid nitrogen 49, impure liquid nitrogen 48, and liquid air 51 are provided separately from the high-pressure column 22 as liquid flowing through the low-pressure column 24 installed at the top of the double column. Introduced via a cooler. The air fed to the turbine by extruding a part of the raw air is cooled, passed through 52, and introduced into the low-pressure column 24 together with the air 56 evaporated in the condenser 26 of the crude argon column. The liquid that has descended in the low-pressure column 24 evaporates by exchanging heat with the nitrogen in the high-pressure column in the heat exchanger 23 and becomes a rising gas in the column. Product oxygen gas 59 from the upper part of the liquid reservoir at the bottom of the low pressure column 24, product nitrogen gas 57 from the top, and impure nitrogen gas 58 from the middle stage are rectified and separated in the low pressure column 24 and discharged outside. You. Oxygen gas containing a small amount of argon is removed from the middle stage of the low-pressure column 24 and sent to the bottom of the crude argon column 25 through 54. The gas that has risen in the crude argon column 25 exchanges heat with liquid air in the condenser 26 and contracts to become a liquid flowing in the column. Part of the ascending gas is sent as crude argon gas through 61 to the argon purification process. The liquid that has descended in the crude argon column 25 is returned to the low-pressure column 24 via 55 from the bottom. Such towers and connecting pipes are provided by filling a cooling material called perlite in a cooling container 62. The packed packing for gas-liquid contact as a rectification element can be applied to any of the high-pressure column 22, the low-pressure column 2 and the crude argon column 25, but in this embodiment, the packed packing is applied to each column. 20 built-in. Further, the liquid distributor 11 of the present invention is incorporated in each of the towers into which the liquid flows or merges. In particular, in the upper tower 24, the rectification region is divided into five from the process due to the process. For this purpose, five liquid distribution devices 11 are provided. Since the height of the liquid distribution apparatus of the present invention is about half (about lm) of the conventional example, the height of the upper tower can be kept low by about 5 m. Since the height of the upper tower of an industrial-scale air separation device is about 30 to 40 m, it is very effective in reducing the height of the rectification tower. In the case of the crude argon tower 25, the number of theoretical plates required for distillation reaches 40 to a maximum of 200. For gas separation in air separation equipment The height of the HETP of the structured packing, that is, the theoretical plate is about 200 mm, which is known. In the case where 200 theoretical stages are provided, the height of the packing reaches 40 meters. It has a great effect on reducing the height of the tower. Furthermore, a reduction in the amount of piping material and a reduction in the height of the cooling tank have a great effect on miniaturization of the entire air separation device.

 As described above, according to the present invention, it is possible to avoid the drawbacks of the conventional device, to improve the separability of liquid, and to provide a small liquid distribution device. As a result, there is an effect that a compact packed tower having a built-in packing can be achieved. Further, by providing the packed column of this embodiment in an air separation device, there is an effect that the device can be reduced in size and cost. Industrial applicability

 According to the present invention, the falling liquid can be collected and uniformly dispersed while allowing the ascending gas to pass therethrough, so that it can be used for a gas-liquid contact device (rectification column) such as an air separation device. Moreover, according to the present invention, it is possible to collect and uniformly disperse the falling liquid by using a device whose height is significantly reduced as compared with the conventional one. Can be greatly reduced.

Claims

The scope of the claims 1. Liquid distribution that is installed above the packing material or in the middle of the packing material, collects the liquid flowing from above and distributes the liquid to the packing material below, and allows the gas from below to pass upward. In the apparatus, a liquid receiving plate for receiving the liquid, a circular liquid receiving plate having a weir plate provided with at least one opening, and a liquid flowing down from at least one opening of the liquid receiving plate are collected, and the liquid is collected. A first liquid distribution box having a hole at the bottom for distributing, and a plurality of second liquid distribution boxes having a plurality of holes at the bottom provided below the first liquid distribution box. Liquid dispensing device. 2. At least one buffer plate is provided at an opening of the liquid receiving tray, a liquid inflow portion of the first liquid distribution box, and a liquid inflow portion of the second liquid distribution box. Liquid distribution device.  3. The liquid distribution device according to claim 2, wherein the buffer plate is made of a perforated plate or a wire mesh. 4. The liquid distribution device according to any one of claims 1 to 3, wherein the receiving plate is inclined so that the liquid flowing down is guided to the outer periphery of the circular liquid receiving tray.  5. The at least one opening provided in the circular liquid receiving tray is provided in the center, and has a plurality of weir plates on both sides of the opening. The liquid dispensing device according to any one of the above.  6. The liquid distribution apparatus according to any one of claims 1 to 5, wherein each of the first liquid distribution box and the second liquid distribution box is rectangular. 7. The method according to any one of claims 1 to 5, wherein the first liquid distribution box is rectangular, and the second liquid distribution box is composed of a plurality of annular groups. A liquid dispensing device according to any of the preceding claims.  8. The method according to claim 1, wherein the first liquid distribution box is rectangular, and the second liquid distribution box is composed of a plurality of tubes. Liquid dispensing equipment. 9. The first liquid distribution box is constituted by an annular liquid distribution box having a plurality of openings for allowing gas from below to pass upward, and the second liquid distribution box is rectangular. The liquid distribution device according to any one of claims 1 to 5, wherein:  10. A rectification column for separating at least one liquid component, wherein the rectification column is provided with a gas-liquid through a packing between 10 which is an ascending flow and a liquid which is a downflow. A rectification column for contacting, wherein the rectification column is provided with at least one liquid distribution device according to any one of claims 1 to 9, wherein the packed column is provided. .  11. An air separation device comprising at least a column comprising the packed column according to claim 10.  12. An air separation apparatus comprising a double rectification column comprising a high pressure column and a low pressure column and an argon column for rectifying argon, wherein the low pressure column and the argon column are described in claim 10. An air separation device comprising a packed tower.  13. An air separation apparatus provided with a double rectification column comprising a high pressure column and a low pressure column and an argon column for rectifying argon, wherein the high pressure column, the low pressure column, and the argon column are claimed in claim 10. An air separation device comprising the packed tower described in (1). 14. When collecting and distributing liquid flowing down from above, the liquid is received by a liquid receiving plate, and there is a weir plate provided with at least one opening. The received liquid is guided to the outer peripheral edge of the circular liquid receiving tray, and the liquid is guided from the outer peripheral edge of the liquid receiving tray to the at least one opening. The first liquid distribution box having a hole at the bottom is used for the at least one liquid. The liquid flowing down from the two openings is collected, and the liquid is distributed from the holes of the first liquid distribution box to the second liquid distribution box having a large number of holes at the bottom). A liquid dispensing method characterized by performing liquid dispersion from a large number of holes.  15. The liquid distribution method according to claim 14, wherein the at least one opening is provided at a central portion of the liquid receiving tray.