JP7243057B2 - Gas-liquid contactor - Google Patents

Description

The present disclosure is a gas-liquid contact that promotes mass transfer or energy transfer by gas-liquid contact, which can be used as a gas purification device, a gas separation device, or a cooling device that separates, removes, or recovers specific gas components. Regarding the device.

Conventionally, in chemical plants, thermal power plants, etc., gas separation devices have been used to separate, remove, or recover specific gases from gases to be treated, such as exhaust gases containing various types of gases, using gas-liquid contact. there is For example, in a carbon dioxide recovery system, carbon dioxide is absorbed and separated by bringing a gas containing carbon dioxide into contact with an absorption liquid such as a monoethanolamine aqueous solution, and the absorption liquid after absorption is brought into gas-liquid contact while being heated. Carbon dioxide is recovered by releasing it into the gas phase. In gas purification equipment for removing harmful gas components from exhaust gas and gas separation equipment for separating specific gas components from mixed gas, gas-liquid contact is used to absorb specific gas components with absorption liquid. done. In addition, gas-liquid contact is also used in chillers for cooling hot liquids or gases.

Patent Literature 1 listed below describes an apparatus for recovering carbon dioxide using gas-liquid contact. Patent Literature 2 below describes a carbon dioxide recovery apparatus in which an absorption tower is constructed by vertically stacking two absorption units.

In general, a device for gas-liquid contact has a filler for increasing the contact area between the liquid and the gas, and the liquid and the gas are brought into gas-liquid contact on the surface of the filler to obtain a specific gas in the gas. Absorb ingredients or heat into a liquid. Typically, a liquid distributor is placed above the packing to prevent maldistribution of the liquid to the packing and to achieve good gas-liquid contact.

Patent Document 3 below describes a liquid distributor for a packed column. In this liquid distributor, the liquid flows out from the side wall opening of the main passage to the plurality of secondary passages, and the liquid is distributed from the secondary passages to the packing material. Further, the liquid distributor described in Patent Document 4 below has an upper part pipe and a lower part pipe, and the liquid is distributed and supplied from nozzle holes of these distribution pipes.

Japanese Patent No. 6225572 Japanese Patent No. 5966565 Japanese Patent No. 4070508 Japanese Patent No. 5057372

In order to increase the gas-liquid contact efficiency, it is effective to carry out the gas-liquid contact in multiple stages to lengthen the contact time. For this reason, as in Patent Document 2, in the absorption tower and the regeneration tower, a plurality of gas-liquid contacting sections are generally stacked vertically to form a multistage structure. In such a vertical multistage absorption tower, gas flows vertically from the bottom to the top of the absorption tower. For this reason, the liquid distributor arranged above the filler is configured in a complicated shape as in Patent Documents 3 and 4 above in order to reduce pressure loss due to flow resistance when gas is supplied. Therefore, there arises a problem of labor and cost in the manufacturing process.

In addition, since the height of the column is limited based on design strength and the like, if the packing height of the packing material is limited by the liquid distributor, it is disadvantageous in improving the gas-liquid contact efficiency.

The present disclosure has been invented in view of the above-described problems, and can realize good and efficient gas-liquid contact with the liquid supplied from the liquid distributor while suppressing the pressure loss in the gas-liquid contact. An object of the present invention is to provide a gas-liquid contactor.

In order to solve the above problems, the present inventors have studied a multi-stage structure of a gas-liquid contactor and a liquid supply to a packing material, and have found that good liquid distribution and gas-liquid distribution can be achieved in a horizontal multi-stage gas-liquid contactor. A configuration capable of achieving contact was found.

According to one aspect of the present disclosure, a gas-liquid contactor includes: a gas-liquid contact portion having a plurality of flat plates arranged side by side in an upright position; a liquid supply system including a liquid distributor that supplies a liquid to the plurality of flat plates from above; and a gas-liquid contactor having a gas supply system in which gas is laterally circulated between the plurality of flat plates by supplying the gas to the gas-liquid contact portion, wherein the liquid distributor includes a plurality of sprayers. a distribution tray having holes; and a liquid inlet tube for supplying liquid to the distribution tray, the liquid inlet tube having an outlet for discharging liquid laterally toward the outer periphery within the distribution tray. is the gist.

The distribution tray has a horizontal plate-like distribution plate having the plurality of spray holes, and a side wall that surrounds the outer periphery of the distribution plate, and the outlet of the liquid inflow pipe is located on the side wall. may be configured to discharge the liquid toward the The liquid inflow pipe has a vertical introduction section that introduces the liquid from above the liquid distributor into the liquid distributor, and a discharge section that bends laterally from the introduction section and has the outlet at the end. can be configured to have Preferably, the liquid inlet tube discharges liquid horizontally from the outlet. The distribution plate may be rectangular and the liquid inlet tube may be configured to have four outlets for discharging liquid along diagonal directions of the distribution plate.

The plurality of spray holes may be configured to vertically penetrate the distribution plate to vertically spray the liquid in the distribution tray. Alternatively, the plurality of spray holes may pass through the distribution plate obliquely from the vertical direction, and the liquid in the distribution tray may be distributed in a direction inclined from the vertical direction. Further, among the plurality of spray holes, the spray holes distributed at the outer edge of the distribution plate penetrate the distribution plate at an angle from the vertical direction so that the liquid spreads outward and is sprayed. The holes may extend vertically through the distribution plate to distribute the liquid vertically.

The plurality of spray holes are arranged along a plurality of parallel straight lines, the spray holes arranged along one straight line of the plurality of straight lines are inclined in the same direction, and two adjacent straight lines of the plurality of straight lines are arranged. It is also possible to form the plurality of spray holes such that the directions of inclination of the spray holes in a straight line are in opposite directions.

The liquid supply system further includes a detector for detecting the liquid surface level of the liquid stored in the distribution tray, and maintaining the amount of liquid stored in the distribution tray at a predetermined amount based on the detection by the detector. It may be configured to have a control device for controlling the supply of liquid to the liquid distributor as described above. Alternatively, the side wall has an overflow hole for maintaining a predetermined amount of liquid stored in the distribution tray, and the liquid supply system distributes the liquid discharged from the overflow hole through the plurality of flat plates. You may comprise so that it may collect|recover with the liquid which flowed down. Preferably, the gas-liquid contact portion has a plurality of stages arranged in a horizontal direction, and the plurality of flat plates are arranged in each of the plurality of stages. The liquid supply system can be configured to have a plurality of the liquid distributors located in each of the plurality of stages.

It is possible to provide a gas-liquid contactor that realizes good liquid distribution and gas-liquid contact while suppressing pressure loss in gas-liquid contact, and that has good energy efficiency during operation.

FIG. 2 is a vertical cross-sectional view showing an example of a liquid distributor according to the present disclosure; FIG. 4 is a vertical cross-sectional view showing another example of a liquid distributor according to the present disclosure; Horizontal sectional views (a) and (b) showing modifications of the liquid distributor. FIG. 4 is a vertical cross-sectional view showing another example of a liquid distributor according to the present disclosure; FIG. 5(a) is a vertical cross-sectional view (a) of a main part showing another example of the liquid distributor according to the present disclosure, and (b) is a cross-sectional view along the line XX in FIG. 5(a). FIG. 4 is a vertical sectional view showing an example of liquid supply in a liquid distributor; FIG. 4 is a vertical sectional view showing another example of liquid supply in the liquid distributor; 1 is a schematic configuration diagram showing an embodiment of a gas-liquid contactor according to the present disclosure; FIG.

Embodiments of the present disclosure are described below, by way of example only, with reference to the accompanying drawings. Dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present disclosure. In the specification and drawings, elements having substantially the same function and configuration are given the same reference numerals to omit redundant description, and elements that are not directly related to the present disclosure are omitted from the illustration. .

Using a flat plate (thin layer material) as a filler is effective in suppressing pressure loss due to flow resistance when gas is supplied to the gas-liquid contactor. A flat plate filling material can reduce manufacturing costs, and can be relatively easily loaded into an apparatus. In this case, a large number of vertical plates are arranged side by side, liquid is supplied from above, gas is supplied to the gaps between the plates, and the liquid flowing down on the plates is brought into contact with the gas passing through the gaps. This form of packing material is used in a vertical multi-stage structure gas-liquid contactor, but it can also be applied to a horizontal multi-stage structure. In the horizontal multistage structure, the liquid distributor arranged above the filler has little effect on the flow resistance of the gas flowing in the lateral direction, and does not need to have a complicated shape for allowing the gas to pass through.

However, when a flat plate in an upright position is used as a filler, the gas-liquid contact area tends to decrease due to insufficient wetting of the filler by the liquid. Since the liquid flowing vertically on a flat surface does not easily spread in the horizontal direction, if the distribution of the liquid is uneven, there will be a surface that is not wetted by the liquid, and the gas-liquid contact efficiency will decrease. Therefore, it is important to devise ways to fully utilize the entire surface of the filler. In the present disclosure, in a gas-liquid contactor in which a plurality of flat plates arranged side by side in an upright position are configured to have a horizontal multi-stage structure as a packing material, a liquid distributor capable of efficiently supplying liquid to the packing material is presented, and a horizontal multi-stage structure is provided. Realize good gas-liquid contact by making use of the advantages in

An embodiment of a liquid distributor applicable to a gas-liquid contactor having a horizontal multistage structure will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing one embodiment of a liquid distributor.

The liquid distributor 1 of FIG. 1 has a distribution tray 2 with a plurality of spray holes H, and two liquid inlet pipes 3 that supply liquid to the distribution tray 2. The distribution tray 2 has a thin box shape. have The liquid inflow tube 3 has an outlet 3e that discharges the liquid toward the outer circumference inside the distribution tray 2. As shown in FIG. Specifically, the liquid inflow pipe 3 has a vertical introduction portion 3i for introducing the liquid into the liquid distributor 1 from above the liquid distributor 1, and a discharge portion 3d bent laterally from the introduction portion 3i. and the liquid is discharged laterally from an outlet 3e at the end of the discharge portion 3d.

The distribution tray 2 has a horizontal plate-like distribution plate 2p and side walls 2w that surround the outer periphery of the distribution plate 2p. Accordingly, the liquid sent from the introduction portion 3i of the liquid inflow pipe 3 to the discharge portion 3d is discharged laterally from the outlet 3e toward the side wall 2w. The plurality of spray holes H are cylindrical holes that penetrate the distribution plate 2p in the vertical direction, and are provided so as to be evenly distributed on the distribution plate 2p. The liquid L discharged from the liquid inflow pipe is supplied inward from the outer peripheral side of the distribution plate 2p at the bottom of the distribution tray 2, is stored on the distribution plate 2p, and is vertically discharged from the distribution hole H of the distribution plate 2p. emitted in the direction Although FIG. 1 shows the upper surface of the liquid distributor 1 in an open state, it is preferable to cover the upper surface with a flat lid or the like to prevent contamination of the inside. In addition, when the inside of the gas-liquid contactor in which the liquid distributor is installed is pressurized, an air hole communicating between the inside and the outside of the liquid distributor is appropriately provided in the side wall or the lid of the liquid distributor, so that the pressure inside and outside the liquid distributor is reduced. differences can be eliminated. Illustrations relating to this point are omitted in the present disclosure.

As shown in FIG. 1, the liquid inflow pipe that discharges the liquid laterally toward the outer circumference is advantageous in constructing a thin liquid distributor that distributes the liquid at a large flow rate. In the case of a liquid inflow pipe that discharges liquid in the vertical direction, the flow pressure of the liquid tends to concentrate on the spray hole directly below the liquid inflow pipe. It must be installed in a high position away from the hole. In comparison, when the liquid is discharged toward the outer circumference as shown in FIG. 1, the fluid pressure from the liquid inflow pipe does not directly act on some of the spray holes, and the liquid spreads evenly on the distribution plate 2p. It is discharged from the spray hole H.

The direction in which the liquid is discharged from the outlet 3e of the liquid inflow tube 3, that is, the direction in which the discharge portion 3d extends is optimally horizontal, but may be inclined upward or downward. In this case, the inclination of the discharge portion 3d affects the repair frequency of the liquid inflow pipe, the inflow pressure of the liquid, and the like, so these factors should be considered in the design.

A liquid distributor 1 in FIG. 1 has a plurality (two) of liquid inlet pipes 3 . However, it is also possible to integrate a plurality of liquid inlet tubes into one, for example as shown in FIG. In the liquid distributor 1A of FIG. 2, the liquid inflow pipe 3A is composed of one vertical introduction portion 3i and a plurality of (two in FIG. 2) discharge portions 3d branching horizontally from the introduction portion 3i. . That is, the introduction part of the liquid inflow pipe is integrated. In the liquid distributor 1 shown in FIG. 1, such integration of the introduction section may be performed outside the distribution tray 2, that is, above.

The liquid inflow tube can be variously modified with respect to the number of discharge portions 3d and outlets 3e, and the direction in which liquid is discharged. FIG. 3 shows a variation in the liquid inlet pipe branching from one inlet as in FIG. 2 to a plurality of outlets. It should be noted that illustration of spray holes is omitted in FIG.

FIG. 3(a) describes a liquid distributor 1B using a liquid inflow tube 3B having four discharge sections 3d branched from one introduction section 3i. The four discharge portions 3d of the liquid inflow pipe extend along the diagonal direction of the rectangular distribution plate 2p and discharge the liquid diagonally from the four outlets 3e toward the four corners. That is, the liquid is supplied toward the farthest corner from the center of the distribution plate 2p.

FIG. 3(b) describes a liquid distributor 1C using a liquid inflow pipe 3C in which discharge sections 3d extending from one introduction section 3i are branched at a plurality of locations. A discharge portion 3d of the liquid inflow pipe 3C has eight outlets 3e by branching at three points, and discharges the liquid from each outlet 3e perpendicularly to the side wall 2w. By increasing the number of branches of the discharge portion 3d of the liquid inflow pipe 3C in this manner, the number of outlets 3e, that is, the number of liquid discharge points can be increased. Although the number of outlets 3e may be one, increasing the number of outlets 3e facilitates uniform supply of liquid. In the structure of the discharge part 3d as shown in FIG. 3(a), a branching form as shown in FIG. 3(b) may be used, and the number of outlets 3e can be increased by branching. It is preferable that the discharge part 3d and the outlet 3e are arranged symmetrically.

In FIGS. 1 and 2, the distribution holes H vertically penetrate the distribution plate 2p to vertically distribute the liquid in the distribution tray. By having the cylindrical sprinkling hole H have a certain length or more, the liquid can be discharged in a straight line. Therefore, the distribution plate 2p should preferably have a thickness of about 8 mm or more. Alternatively, if the thickness is less than this, nozzles projecting downward from the distribution plate 2p may be formed to extend the length of the spray holes. Further, from the viewpoint of uniform distribution of the liquid, the distribution holes H are preferably arranged at regular intervals. If the interval between spray holes (distance between openings) is small, the liquids discharged from a plurality of adjacent spray holes are likely to be integrated.

In FIGS. 1 and 2, all the distribution holes H are configured to penetrate the distribution plate 2p in the vertical direction so that the liquid L in the distribution tray 2 is distributed in the vertical direction. However, the spray holes may not be vertical. For example, part or all of the spray holes may be formed so as to be inclined from the vertical direction. FIG. 4 shows an embodiment of a liquid distributor with sparge holes slanted from the vertical. A liquid distributor 1D in FIG. 4 has a distribution tray 2D in which a portion of the spray hole H is inclined from the vertical direction. Specifically, among the many spray holes, the spray holes H′ distributed on the outer edge of the distribution plate 2p penetrate the distribution plate 2p at an angle from the vertical direction so that the liquid L spreads outward and is sprayed. do. The remaining spray holes H vertically penetrate the distribution plate 2p so as to spray the liquid L vertically. Such a configuration is advantageous in supplying liquid to all of the flat plates arranged in parallel below the liquid distributor, and can prevent insufficient wetting of the outermost flat plates. In addition, the liquid spread outwardly from the liquid distributor can reflect the inner surface of the side wall of the gas-liquid contactor and wet the flat plate.

In FIG. 4, the spray holes H' inclined from the vertical direction are arranged in a line on the outermost periphery of the distribution plate 2p. However, the slanted distribution holes need not be limited to only one row on the outermost periphery, and several or more rows of slanted distribution holes may be provided. In this case, the inclination angle may be different between the outermost periphery spray hole and the inner spray hole. The inclination angle of the spray holes with respect to the vertical direction can be appropriately set as necessary. In general, when the inclination angle is in the range of about 0 to 30 degrees, drilling is relatively easy, and good consistency is obtained between the design angle and the actual spray angle.

FIG. 5 shows an embodiment of a liquid distributor configured such that all of the distribution holes are inclined from the vertical direction and pass through the distribution plate 2p. In the liquid distributor 1E shown in FIG. 5, the spray holes Ha and Hb are arranged along a plurality of straight lines parallel to each other at regular intervals and perpendicular to the flat plate P arranged below. The spray holes Ha and Hb are arranged such that the spray holes arranged along one straight line out of the plurality of straight lines are inclined in the same direction, and the directions of inclination of the spray holes on two adjacent straight lines are opposite to each other. is formed. Specifically, the distribution holes Ha arranged on one straight line pass through the distribution plate 2p along the vertical plane including the straight line, and are inclined in the same direction at the same angle with respect to the vertical direction. The distribution holes Hb arranged on the adjacent straight line pass through the distribution plate 2p along the vertical plane including the straight line, and are inclined in the opposite direction to the distribution holes Ha at the same angle with respect to the vertical direction. Therefore, the spray holes Ha and Hb of the distribution tray 2E spray the liquid L alternately on one flat plate P from opposite directions. In other words, this configuration is advantageous for evenly distributing the liquid from both sides of the flat plate P to both sides. In this configuration, if the pitch (the number of holes per distance) of the spray holes arranged on one straight line is designed to match the pitch of the lower flat plates P arranged side by side, the spray efficiency will be good.

As described above, the distribution trays and the liquid inflow pipes that constitute the liquid distributor are capable of various applications and modifications, and the liquid distributor may be configured by combinations other than those shown in the drawings. For example, in each of the liquid distributors 1D and 1E shown in FIGS. 4 and 5, the liquid inflow pipe 3A may be replaced with any one of the liquid inflow pipes 3, 3B and 3C shown in FIGS. good too.

In the liquid distributor shown in FIGS. 1 to 5, the opening area of the spray holes is determined by setting the number and diameter of the spray holes formed in the distribution plate 2p. The spraying speed of the liquid L from the liquid distributor can be adjusted by the opening area of the spraying holes. In addition, in such a liquid distributor, the minimum flow rate at which the liquid can be evenly sprayed from all the spray holes (the flow rate at which the liquid flows evenly with a constant head pressure in all the spray holes), and the processable There is a maximum flow rate. The minimum and maximum flow rates are determined by the open area of the spray holes. Taking these factors into consideration, the liquid can be suitably sprayed continuously by adjusting the flow rate of the liquid supplied from the liquid inflow pipe so that a constant amount of liquid is stored in the distribution tray. A configuration for performing such liquid supply will be described below.

FIG. 6 is a vertical cross-sectional view perpendicular to the longitudinal direction of the gas-liquid contactor 10 and describes one of the stages of the gas-liquid contactor 11 . The gas-liquid contact part 11 is configured inside a long and narrow substantially rectangular container 12, and a plurality of stages are allocated so as to be arranged in the horizontal direction along the longitudinal direction. A plurality of flat plates P are arranged in parallel in an upright position on each of the plurality of stages of the gas-liquid contact portion 11 . A liquid supply system that supplies liquid to the gas-liquid contact portion 11 is configured using a plurality of liquid distributors as described above. Although the liquid distributor 1A of FIG. 2 is used in the embodiment of FIG. 6, other liquid distributors may of course be used. A plurality of liquid distributors 1A (only one is shown in this figure) are arranged above the plate P in each of the plurality of stages. The liquid distributor 1A supplies the liquid L to the plurality of flat plates P from above.

The liquid L flowing down along the flat plate P is stored at the bottom of the container 12 . A discharge port 13 provided at the center of the bottom of the container 12 is connected to the liquid inlet pipe 3A of the liquid distributor 1A by a return path 14, and a pump 15 is installed in the return path 14. As shown in FIG. By driving the pump 15, the liquid L stored in the bottom of the container 12 is returned to the liquid inflow pipe 3A of the liquid distributor 1A through the return path 14. FIG. The liquid L supplied from the discharge section 3d to the distribution tray 2 is again distributed to the flat plate P from the liquid distributor 1A.

In order to keep the amount of liquid L stored in the distribution tray 2 at a predetermined amount, the liquid supply system includes a detector 16 that detects the liquid surface level and a controller that controls the liquid supply to the liquid distributor 1A. have Specifically, a detector 16 for detecting the liquid surface level of the liquid stored in the distribution tray 2 is installed on the side wall 2w. A connected adjustment path 17 is provided. Flow rate control valves 18 and 19 are installed in the return path 14 and the adjustment path 17 , and the flow rate control valves 18 and 19 are electrically connected to the detector 16 .

When the liquid level detected by the detector 16 exceeds a predetermined level (or the upper limit of the predetermined range), the opening degree of the flow control valve 18 decreases and the opening degree of the flow control valve 19 increases based on the detection signal. , the flow rate of the liquid L returned from the regulating passage 17 to the upstream side of the pump 15 increases. This reduces the flow rate of the liquid supplied to the liquid distributor 1A. When the liquid level is less than the predetermined level (or the lower limit of the predetermined range), the opening degree of the flow rate adjusting valve 18 increases and the opening degree of the flow rate adjusting valve 19 decreases, thereby decreasing the flow rate of the liquid supplied to the liquid distributor 1A. increases. In this way, the opening degrees of the flow control valves 18 and 19 are adjusted, and the flow rate of the returned liquid is controlled so that the liquid level in the liquid distributor 1A is maintained constant (or within a predetermined range). can be done. In this manner, the control device can be constructed using the adjustment path 17 and the flow rate adjustment valves 18 and 19, and the amount of liquid stored in the distribution tray 2 is maintained at a predetermined amount.

Another configuration example for controlling the amount of liquid stored in the distribution tray to be constant is shown in FIG. In the gas-liquid contactor 10' of FIG. 7, an overflow hole 21 is provided in the side wall 2w of the liquid distributor 1A instead of the detector for detecting the liquid level. The overflow hole 21 is provided at a position that maintains the liquid level, and the outlet pipe 22 and the discharge path 23 are connected to the overflow hole 21 . Similar to the gas-liquid contactor 10 of FIG. 6, the gas-liquid contactor 10' is provided with a return path 14 and an adjustment path 17 for supplying the liquid L stored at the bottom of the liquid distributor to the liquid distributor. can be adjusted by flow control valves 18 and 19. The discharge path 23 is connected to the adjustment path 17 , and the amount of liquid exceeding the position of the overflow hole in the liquid distributor is supplied from the outlet pipe 22 through the discharge path 23 to the adjustment path 17 . Therefore, the liquid discharged from the overflow hole is recovered together with the liquid stored at the bottom and supplied to the liquid distributor again.

6 and 7, the liquid distribution from the liquid distributor to the flat plate P of the gas-liquid contact portion 11 is repeated in one stage of the gas-liquid contact portion. Based on such a configuration of each stage, the gas-liquid contactor can be constructed so that the liquid can be sequentially supplied to adjacent stages as a whole apparatus. Specifically, the gas-liquid contactor is configured so that, at the boundary of a plurality of stages of the gas-liquid contacting section, when the liquid stored at the bottom exceeds a certain amount, it overflows into the adjacent stage (see FIG. 8 for details). (discussed below with reference to ). This allows a gradual transfer of liquid from the upstream stage to the downstream stage by liquid replenishment. Therefore, the liquid can be spread over the flat plate P and circulated sequentially through a plurality of stages. Alternatively, the return path 14 in FIGS. 6 and 7 is not connected to the liquid distributor 1A of the same stage, but is connected to the liquid distributor of the downstream stage, whereby all the liquid stored at the bottom is transferred to the adjacent stage. It is also possible to configure so as to sequentially supply to each of the liquid distributors. Alternatively, the return path 14 may be branched and connected to both the liquid distributor 1A in the same stage and the liquid distributor in the downstream stage.

FIG. 8 is a vertical cross-sectional view along the longitudinal direction for explaining the overall configuration of the gas-liquid contactor 10 based on the liquid distribution configuration of FIG. 1 is an embodiment of a gas-liquid contactor. In the gas-liquid contactor 10 shown in FIG. 8, a structure is used in which the liquid surface level of the liquid stored at the bottom can be maintained at a desired level by setting the height of the partition wall 24 provided at the boundary of a plurality of stages. . In other words, when the liquid surface level reaches the height of the partition wall 24, the liquid flows from the upstream stage to the downstream stage by utilizing the property that the liquid overflows due to the increase in the amount of liquid and moves to the next stage. step-by-step. In FIG. 8, illustration of electrical connections with the detector 16 and the flow control valves 18 and 19 shown in FIG. 6 is omitted.

The gas-liquid contact device 10 has a horizontally elongated container 12 , and a gas-liquid contact section 11 having a plurality of steps is constructed inside the container 12 . The container 12 has a top plate 12t, a bottom plate 12b and a pair of side plates 12s along the longitudinal direction, and end walls 12a and 12d at both ends in the longitudinal direction. The shape of the container 12 is a substantially quadrangular prism shape (see FIG. 6) with a substantially rectangular cross section perpendicular to the longitudinal direction. A plurality of stages of the gas-liquid contact portions 11 are allocated along the longitudinal direction of the container 12 so as to be arranged in the lateral direction. A plurality of flat plates P are installed side by side in an upright position on each of the plurality of stages. In this embodiment, four stages are assigned to the gas-liquid contact portion 11, but the number of stages to be allocated may be any number of two or more. Allocated to the appropriate number of stages. Also, in this embodiment, the plurality of stages are substantially evenly distributed, and flat plates P of the same size are used as fillers, but if necessary, the longitudinal length of each stage is different. It can also be changed.

The liquid supply system of the gas-liquid contactor 10 has a plurality of liquid distributors 1A each arranged in a plurality of stages of the gas-liquid contact section 11, and each of the plurality of liquid distributors 1A is supplied through a piping system. A plurality of flat plates P are supplied with the liquid L from above. The piping system is composed of an introduction path 25 , a return path 14 and an outlet path 26 . The introduction path 25 is connected to the liquid distributor 1A in the most upstream stage to which the liquid is first supplied, and the liquid supplied from the liquid distributor 1A to the plate P flows down to the bottom of that stage. The bottom plate 12b of the container 12 is formed in a concave shape inclined so that the center is the lowest for each stage, and the discharge port 13 is connected to the bottom of the concave shape. Accordingly, the liquid supplied to the liquid distributor 1A flows down along the surface of the flat plate P from the liquid distributor 1A, is accumulated at the bottom, and is discharged from the discharge port 13 to the return path 14. FIG.

The return path 14 connects the plurality of liquid distributors 1A and the plurality of discharge ports 13 so that the discharge port 13 and the liquid distributor 1A in each stage communicate with each other. Accordingly, when the pump 15 on the return path 14 is driven, the liquid recovered from the discharge port 13 is returned to the liquid distributor 1A and repeatedly supplied to the flat plates P of each stage. As described with reference to FIG. 6, the level of the liquid stored in the liquid distributor 1A is maintained by the action of the detector (not shown in FIG. 8) and the flow control valves 18 and 19. FIG. Therefore, it is possible to maintain the liquid spray from the liquid distributor 1A in a suitable state, and to evenly spray the liquid onto the flat plate P at a constant flow rate.

A partition wall 24 is erected at the bottom of the container 12 at the boundary of each step in the gas-liquid contact portion 11 . Due to the liquid supply from the introduction passage 25, the amount of liquid stored at the bottom of the most upstream stage (with respect to the liquid flow direction) increases, and when the height of the partition wall 24 is reached, the amount corresponding to the new supply amount increases. Liquid overflows from the bottom of this step onto the next step. Therefore, the amount of liquid retained in each stage is regulated to a predetermined amount, and when this is exceeded, the excess liquid is fed to the bottom of the downstream stage. In this manner, liquid is supplied sequentially from upstream stages to downstream stages. The amount of liquid stored in the bottom of each stage can be adjusted by adjusting the height of the partition wall 24 . Therefore, the ratio of the liquid supplied from the bottom of each stage to the downstream stage and the liquid returning to the original stage can be set and changed by the height of the partition wall 24 .

The gas-liquid contactor 10 has a liquid recovery port 27 between the end wall 12d of the vessel 12 and the most downstream stage, and a partition wall 24' is also provided at the boundary between the liquid recovery port 27 and the most downstream stage. be done. A lead-out path 26 is connected to the liquid recovery port 27 . Therefore, when the liquid stored at the bottom of the most downstream stage overflows over the partition wall 24', it is discharged from the liquid recovery port 27 through the lead-out path 26. Although the liquid recovery port 27 is provided at the bottom of the container 12 in FIG. 8, it may be provided at the side plate 12s or the end wall 12d of the container. In this case, the height of the liquid recovery port 27 should be set so that the amount of liquid exceeding the desired liquid level overflows from the liquid recovery port 27 at the bottom of the most downstream stage. Thereby, the partition wall 24' can be omitted and the longitudinal length of the device can be shortened.

On the other hand, the gas-liquid contactor 10 has a tubular gas inlet 28 and gas outlet 29 as a gas supply system. A gas inlet 28 is provided in the center of the end wall 12d, and a gas outlet 29 is provided in the center of the opposite end wall 12a. The gas inlet 28 communicates with the most downstream stage through which the liquid flows last, and the gas outlet 29 communicates with the most upstream stage through which the liquid first circulates. Therefore, by supplying the gas G from the gas introduction port 28, the gas G supplied to the gas-liquid contact portion 11 sequentially circulates along the arrangement of the plurality of stages in the direction opposite to the liquid flow direction. That is, the gas-liquid contactor 10 is configured to perform countercurrent gas-liquid contact. Of course, by arranging the gas inlet 28 and the gas outlet 29 in reverse, it is possible to modify to implement co-current gas-liquid contact. In the embodiment of FIG. 8, the gas supply system supplies the gas G using the flow pressure of the gas G supplied from the outside, and the power source for gas supply is not particularly described, but if necessary, Alternatively, an air delivery means such as a pump or fan may be used.

A demister 30 is installed near the gas outlet 29 to prevent fine droplets from being accompanied by the gas G' discharged from the gas outlet 29 . As the demister 30, a mesh-like or porous member such as a wire mesh or a perforated plate can be used, and one having a suitable opening size can be selected from those generally used as demisters. Moreover, a partition plate 31 bridging between the side plates 12 s of the container 12 is provided on the upper side at the boundary of each stage in the gas-liquid contact portion 11 . The partition plate 31 is designed so that its upper end contacts the lower surface of the liquid distributor 1A and its lower end reaches the upper end of the flat plate P, and is installed so as to contact the corner of the flat plate P. In other words, the space above the flat plate P is cut off at the boundary of each stage of the gas-liquid contact portion. Therefore, the partition plate 31 serves to prevent the gas G from flowing above the space between the flat plates P. Since the partition plate 31 having an excessive height increases the flow resistance of the gas G, the partition plate 31 should be designed with an appropriate height in consideration of this point.

Therefore, the gas G supplied from the gas inlet port 28 flows laterally in the space between the flat plates P at each stage of the gas-liquid contact portion, and passes through each stage in sequence along the longitudinal direction of the device to reach the gas. It is discharged from the discharge port 29 . In such a horizontal multistage structure, it is possible to prevent the gas G flowing through the gas-liquid contact portion 11 from flowing into the liquid distributor 1A.

In addition, when using a spacer for appropriately fixing the distance between the flat plates P, the spacer may be installed using the partition wall 24 or the partition plate 31 . Alternatively, if a shallow vertical groove having a width capable of fitting the side end of the flat plate P is formed in the side surface of the partition wall 24 and the partition plate 31, the side end of the flat plate P can be held and positioned in the groove. It is possible and acts as a spacer.

Also, in the embodiment of FIG. 8, a plurality of flat plates P are individually arranged in each of the plurality of stages. However, since the tiers communicate laterally with each other, modifications such as using a common flat plate in multiple tiers are possible. That is, even if a plurality of flat plates having a length equal to the length in the longitudinal direction of the gas-liquid contact portion 11 (=the sum of the lengths in the longitudinal direction of the plurality of stages) are arranged side by side so as to penetrate the plurality of stages. good. Therefore, as each of the plurality of vertical flat plates P, it is possible to use a horizontally elongated flat plate that is integrally continuous through a plurality of steps. At this time, if necessary, notches for fitting the partition wall 24 and the partition plate 31 can be formed in the upper and lower ends of each flat plate for better installation. Alternatively, a plurality of notches may be formed in the lower end of the partition plate 31 and the upper end of the partition wall 24, and a flat plate may be fitted into the notches. In this case, the partition wall 24, the partition plate 31 and the notch can also act as positioning means for the flat plate.

When the gas-liquid contactor 10 is used as an absorber, the liquid L sprayed on the flat plate P flows down along the surfaces of the vertically erected flat plates, while flowing laterally in the space between the flat plates. contact with gas G; During this gas-liquid contact, the liquid L forms a liquid film on the flat plate P and absorbs specific components in the gas G, for example. The gas G' from which the specific component has been removed is discharged from the gas outlet 29 to the outside. The liquid L sprayed onto the flat plate P in each stage gradually moves from the upstream stage to the downstream stage. The liquid L′ that has functioned as the absorbing liquid is recovered through a lead-out path 26 connected to the liquid recovery port 27 of the container 12 . A heat exchanger 32 is installed in the reflux path 14, and the temperature of the liquid can be adjusted according to the temperature change of the liquid due to the reaction during the gas-liquid contact. In the absorption reaction of carbon dioxide by the absorption liquid, the temperature of the liquid rises due to heat generation.

The wetted area per unit volume (gas-liquid contact area), gas flow rate, and gas flow resistance change depending on the thickness and spacing of the flat plates P. number is set. The arrangement of the spray holes of the liquid distributor is also appropriately determined in consideration of the thickness and spacing of the flat plate P. The interval between the flat plates can be fixed by interposing spacers, for example. The size and installation position of the spacer may be appropriately adjusted so as not to hinder the flow of gas and liquid. In the gas-liquid contactor 10, the space in which the gas G and the liquid L flow is the gap between the parallel flat plates P having a straight and simple shape, so that the flow resistance is low. The gas-liquid contactor as described above is advantageous in terms of operating costs, etc., since the flow resistance of the gas when the gas and the liquid are brought into contact with each other affects the energy consumption during operation. In addition, manufacturing costs can be kept low. Therefore, it is useful as a gas-liquid contactor that requires large-capacity treatment and high-speed treatment.

When a thin flat plate is used to increase the gas-liquid contact area per unit volume, a reinforcing means may be used to supplement the strength of the thin flat plate, if necessary. Examples of reinforcing means include a mode in which ribs are attached to both sides of a flat plate, and a mode in which a clip or the like is used to support and fix the plate, but any known means may be appropriately selected and applied. A reinforcing effect may be obtained by devising the arrangement of spacers.

The flow of the liquid L flowing down the surface of the flat plate is difficult to spread laterally, and the wetted area (gas-liquid contact area) tends to decrease. In order to suppress the reduction of the wetted area, it is effective to distribute the liquid as evenly as possible on the horizontal upper surface formed by the upper ends of the flat plates. Liquid distributors such as those described in FIGS. 1-5 are capable of uniformly supplying liquid over the entire top surface of the flat plate P regardless of the size and shape of the top surface, without affecting the liquid distribution. In addition, it is easy to change the design corresponding to the dimension of the filling space of the flat plate P. A drip point density of 500 points/m ² or more in the liquid distributor is effective for improving gas-liquid contact performance, and a drip point density of 1000 to 3000 points/m ² is efficient.

Examples of the gas G treated by the gas-liquid contactor described above include waste gas (exhaust gas) and reaction gas generated in facilities such as chemical plants and thermal power plants, and often carbon dioxide and nitrogen. Acid gases such as oxides and sulfur oxides are treated as specific components. Depending on the specific component to be removed from the gas G, the liquid L used as the absorption liquid is selected. For example, for the recovery and removal of carbon dioxide, aqueous solutions of alkaline agents such as cyclic amine compounds, alkanol-based amines, phenol-based amines, and alkali metal salts are often used. For removal of sulfur oxides, aqueous solutions of alkaline agents such as calcium compounds and magnesium compounds are generally used. In a monoethanolamine (MEA) aqueous solution, which is often used in the recovery of carbon dioxide, carbamate/amine salt (carbamate), carbonate, bicarbonate, etc. are produced by reaction with carbon dioxide.

For this reason, each part constituting the gas-liquid contactor is made of a material that is resistant to the components of the gas G and chemical agents contained in the liquid L as described above. Examples of such materials include metals such as stainless steel, aluminum, nickel, titanium, carbon steel, brass, copper, monel, silver, tin, and niobium, and resins such as polyethylene, polypropylene, and PTFE. At least the surface of the flat plate constituting the gas-liquid contact portion as the filling material is also made of a corrosion-resistant material that does not react (corrode) with the gas G to be processed and the liquid L to be used, as described above. The material may have surface roughness by forming minute irregularities on the surface by surface treatment such as sandblasting, ultraviolet ozone treatment, plasma treatment, or the like. Moreover, it may be a material prepared to meet the above conditions of use by surface modification such as coating.

The flat plate is a flat plate or a thin layer material with a uniform thickness, and the material and thickness can be appropriately selected according to the conditions for gas-liquid contact so that suitable strength can be maintained. Wire nets using metal wires, perforated metal plates, expanded metal plates, and other mesh plates are plate materials that can reduce weight while maintaining strength to the extent that they can stand on their own. It exhibits excellent properties. Therefore, if the mesh is extremely fine, it can be handled in the same manner as a flat plate, and may be used to constitute a packing material for a gas-liquid contactor.

The gas-liquid contactor is not limited to the gas-liquid contactor for absorbing, separating, and removing specific components as described above, but is used for cooling, heating, diffusion, etc. included in various chemical plant processes. It can also be applied to equipment (cooling tower, heating tower, diffusion tower (regeneration tower), etc.).

A gas-liquid contactor with good energy efficiency during operation is provided, and good gas-liquid contact and efficient component migration can be realized while suppressing pressure loss. Therefore, it is possible to contribute to the prevention of environmental pollution by improving the efficiency in chemical treatment and manufacturing processing, and the spread of treatment of exhaust gas such as combustion gas by generalization based on the improvement of economic efficiency. In addition, it is possible to contribute to the effective use of resources by reducing the weight of the device and reducing the manufacturing and processing costs.

Reference Signs List 1, 1A, 1B, 1C, 1D, 1E Liquid distributor 2, 2D, 2E Distribution tray 3, 3A, 3B, 3C Liquid inflow pipe 10, 10' Gas-liquid contact device 11 Gas-liquid contact part 12 Container 13 Outlet 14 Return channel 15 Pump 16 Detector 17 Adjustment channel 18, 19 Flow control valve 21 Overflow hole 24 Partition wall 25 Introduction channel 26 Lead-out channel 27 Liquid recovery port 28 Gas introduction port 29 Gas discharge port 30 Demister 31 Partition plate L, L' Liquid G, G' gas

Claims (11)

a gas-liquid contact part having a plurality of flat plates arranged in parallel in an upright position;
a liquid supply system having a liquid distributor that supplies liquid to the plurality of flat plates from above; and
A gas-liquid contactor having a gas supply system in which gas is laterally circulated between the plurality of flat plates by supplying the gas to the gas-liquid contact portion,
The liquid distributor is
a distribution tray having a plurality of spray holes; and
having a liquid inflow tube that supplies liquid to the distribution tray;
the liquid inlet tube has an outlet for discharging the liquid laterally toward the outer periphery inside the distribution tray;
The distribution tray has a horizontal plate-like distribution plate having the plurality of spray holes, and a side wall that surrounds the outer periphery of the distribution plate, and the outlet of the liquid inflow pipe is located on the side wall. eject liquid towards
the outlet of the liquid inflow tube opens in the lateral direction;
The liquid inlet tube and the outlet of the liquid inlet tube are spaced apart from the distribution plate of the distribution tray.
Gas-liquid contact device. The liquid inflow pipe has a vertical introduction section that introduces the liquid from above the liquid distributor into the liquid distributor, and a discharge section that bends laterally from the introduction section and has the outlet at the end. The gas-liquid contactor according to claim 1, comprising: 3. The gas-liquid contactor according to claim 1, wherein the liquid inflow pipe discharges the liquid horizontally from the outlet. 2. The gas-liquid contactor according to claim 1, wherein said distribution plate is rectangular, and said liquid inlet pipe has four outlets for discharging liquid along diagonal directions of said distribution plate. 2. The gas-liquid contactor according to claim 1, wherein the plurality of spraying holes penetrate the distribution plate in the vertical direction to spray the liquid in the distribution tray in the vertical direction. Among the plurality of spray holes, the spray holes distributed along the outer edge of the distribution plate pass through the distribution plate at an angle from the vertical direction so that the liquid spreads outward and is sprayed. 2. The gas-liquid contactor of claim 1, vertically penetrating the distribution plate so as to vertically distribute the liquid. 2. The gas-liquid contactor according to claim 1, wherein said plurality of spray holes penetrate said distribution plate obliquely from the vertical direction, and spray the liquid on said distribution tray in a direction inclined from the vertical direction. The plurality of spray holes are arranged along a plurality of parallel straight lines, the spray holes arranged along one straight line of the plurality of straight lines are inclined in the same direction, and two adjacent straight lines of the plurality of straight lines are arranged. 8. The gas-liquid contactor according to claim 7, wherein the plurality of spray holes are formed such that the inclination directions of the spray holes in the straight line are opposite directions. The liquid supply system further comprises:
a detector for detecting the liquid surface level of the liquid stored in the distribution tray; and
2. The gas-liquid according to claim 1, further comprising a control device for controlling supply of liquid to said liquid distributor so as to maintain a predetermined amount of liquid stored in said distribution tray based on detection by said detector. contact device. the side wall has an overflow hole for maintaining a predetermined amount of liquid stored in the distribution tray;
2. The gas-liquid contactor according to claim 1, wherein the liquid supply system recovers the liquid discharged from the overflow hole together with the liquid flowing down the plurality of flat plates. The gas-liquid contact part has a plurality of stages that are allocated to be arranged in a lateral direction, the plurality of flat plates are arranged in each of the plurality of stages, and the liquid supply system includes a plurality of the liquid distributors. 11. The gas-liquid contactor according to any one of claims 1 to 10, wherein the gas-liquid contactor according to any one of claims 1 to 10 is arranged in each of said plurality of stages.

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