Gas-liquid redistributor for small packed tower

Abstract

The utility model relates to the technical field of gas-liquid redistributors, and discloses a gas-liquid redistributor for a small packed tower, which comprises a distribution plate, gas uniform distribution holes and liquid uniform distribution holes are arranged on the distribution plate and are arranged on different circles taking the center of the distribution plate as the center, and the gas uniform distribution holes and the liquid uniform distribution holes are arranged on each circle. The gas uniform distribution holes and the liquid uniform distribution holes are alternately distributed, the distances between two adjacent circles are equal, and the liquid distribution holes of the two adjacent circles are distributed in a staggered manner; a gas distribution pipe and a liquid distribution pipe are respectively arranged above and below the distribution disc, the gas distribution pipe is connected with the gas uniform distribution holes, and the liquid distribution pipe is connected with the liquid uniform distribution holes. The gas-liquid redistributor disclosed by the utility model is suitable for being used in a small-sized gas-liquid mass transfer packed tower, has a simple structure, cuts a gas phase into smaller gas flows, uniformly distributes liquid into smaller liquid drops, and increases the contact area between the liquid and the gas, thereby improving the mass transfer efficiency.

Description

Technical Field

[0001] The utility model belongs to the technical field of gas-liquid redistributors, and in particular relates to a gas-liquid redistributor for a small packed tower. Background Art

[0002] Packed towers are commonly used mass transfer equipment in chemical separation operations. Their operating principle is to utilize the large specific surface area of the packing. When the packing surface is wetted, the liquid automatically spreads along the packing surface, flowing downward in a thin film. Gas flows upward from the lower part of the tower through the pores between the packing, thereby creating a larger contact area between the gas and liquid, and achieving sufficient material exchange between the gas and liquid. Within a packed tower, as the absorbent liquid flows downward through the packing layers, it tends to gradually flow toward the tower walls, which is very likely to cause wall flow. As the absorbent flows along the tower walls, the liquid gradually concentrates, increasing the flow rate. This poor dispersion within the packing layers significantly reduces the efficiency of the packed tower.

[0003] When the ratio of packing layer height to tower diameter exceeds a certain value, it needs to be stratified. To avoid wall flow, a gas-liquid redistributor is installed between packing layers to collect liquid from the previous packing layer and evenly distribute it to the next packing layer. This ensures that the packing layer maintains a high mass transfer efficiency. At the same time, the gas flows evenly through the redistributor, reducing pressure drop and avoiding flooding.

[0004] Common industrial redistributors, such as trough-plate and inclined-plate types, are complex and large in size, making them unsuitable for small experimental setups. Chinese patent CN 117942860 A discloses a small gas-liquid redistributor that can enhance the mass transfer efficiency of packed towers. However, due to the thick downcomers, the droplets flowing down the downcomers are large, making it unsuitable for towers with low spray density. CN 116036991 A discloses a liquid distributor suitable for low spray density and multiple distribution points. This distributor improves distribution uniformity and reduces non-ideal flow conditions in the equipment, but lacks gas circulation and redistribution capabilities.

[0005] A small packed tower refers to a packed tower used in laboratories, and its inner diameter is generally less than 150 mm. Utility Model Content

[0006] The technical problem to be solved by the utility model is to provide a small-sized packed tower gas-liquid redistributor which has a simple structure, is easy to use and is suitable for low spray density.

[0007] In order to solve the above technical problems, the utility model provides a gas-liquid redistributor for a small packed tower, comprising a distribution plate, the distribution plate being provided with gas uniform distribution holes and liquid uniform distribution holes, the aperture of the gas uniform distribution holes being larger than the aperture of the liquid uniform distribution holes;

[0008] The gas uniform distribution holes and liquid uniform distribution holes are arranged on different circles with the center of the distribution plate as the center. On each circle, the gas uniform distribution holes and liquid uniform distribution holes are alternately distributed, the distance between adjacent circles is equal, and the liquid distribution holes in adjacent circles are staggered.

[0009] A gas distribution pipe is provided above the distribution plate. A gas uniform distribution hole is connected to a gas distribution pipe, and the bottom end of the gas distribution pipe is fixedly connected to the top surface of the distribution plate.

[0010] A liquid distribution pipe is provided under the distribution plate, and a liquid uniform distribution hole is connected to a liquid distribution pipe. The liquid distribution pipe includes an upper big head and a lower drainage pipe. The upper big head and the drainage pipe are integrally formed. The upper big head is fixedly connected to the bottom surface of the distribution plate, and the inner diameter of the drainage pipe is smaller than the aperture of the liquid uniform distribution hole.

[0011] As an improvement of a gas-liquid redistributor for a small packed tower of the utility model:

[0012] A flow baffle is provided at the upper end of the gas distribution pipe, and a symmetrically distributed vent hole is provided on the side wall of the flow baffle, and the vent hole is rectangular.

[0013] As a further improvement of the gas-liquid redistributor for a small packed tower of the utility model:

[0014] The distance between the center of the gas uniform distribution hole in the outer ring and the center of the distribution plate is 70-85% of the radius of the distribution plate, the number of the gas uniform distribution holes is at least 4, and the aperture of the gas uniform distribution holes is 7-23% of the inner diameter of the packed tower.

[0015] As a further improvement of the gas-liquid redistributor for a small packed tower of the utility model:

[0016] The diameter of the liquid uniform distribution holes is 1 to 10 mm, and the number of the holes is at least 4.

[0017] As a further improvement of the gas-liquid redistributor for a small packed tower of the utility model:

[0018] The outer diameter of the upper end is 1 to 10 mm, the thickness is 0.2 to 3 mm, and the length is 5 to 30 mm. The outer diameter of the upper end is larger than the outer diameter of the drainage tube.

[0019] The drainage tube has an inner diameter of 0.5 to 2 mm, a thickness of 0.1 to 0.5 mm, and a length of 5 to 20 mm.

[0020] As a further improvement of the gas-liquid redistributor for a small packed tower of the utility model:

[0021] The area of the ventilation holes is 1.2 times or more greater than the cross-sectional area of the gas uniformly distributed holes.

[0022] As a further improvement of the gas-liquid redistributor for a small packed tower of the utility model:

[0023] The outer circumference of the distribution plate is provided with a circle of grooves, and the rubber ring is sleeved in the grooves; a circle of liquid retaining grooves is provided around the top edge of the distribution plate, and the liquid retaining grooves are fixedly connected to the distribution plate, and the height of the liquid retaining grooves is less than the height of the gas distribution pipe.

[0024] As a further improvement of the gas-liquid redistributor for a small packed tower of the utility model:

[0025] The baffle on the outer ring of the gas distribution pipe is provided with a support ear, which is located at the upper end of the baffle and is fixedly connected to the side wall of the baffle.

[0026] The beneficial effects of the present invention are mainly reflected in:

[0027] (1) The gas-liquid redistributor of the present invention is suitable for use in a small gas-liquid mass transfer packed tower, has a reasonable structural design, is simple to manufacture and has low cost.

[0028] (2) In a small gas-liquid mass transfer packed tower, the gas-liquid redistributor greatly reduces the gas-liquid deviation phenomenon, the gas phase flow area is larger, the pressure drop is lowered, the gas phase is cut into smaller airflows, and the liquid is evenly distributed into smaller droplets, which increases the contact area between the liquid and the gas, thereby increasing the mass transfer efficiency.

[0029] (3) When the spray density of the utility model is low, the flow rate of the liquid in the drainage tube is slow, the flow rate at the outlet of each drainage tube is stable, and the droplets are evenly distributed. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The specific implementation of the present invention is further described in detail below with reference to the accompanying drawings.

[0031] Figure 1 This is a schematic structural diagram of a gas-liquid redistributor for a small packed tower according to Example 1;

[0032] Figure 2 for Figure 1 Top view of the central distribution plate.

[0033] Figure 3 This is a schematic structural diagram of a gas-liquid redistributor for a small packed tower according to Example 2.

[0034] Figure 4 for Figure 1 Schematic diagram of the explosion structure of the gas-liquid redistributor. DETAILED DESCRIPTION

[0035] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto:

[0036] Example 1: A gas-liquid redistributor for a small packed tower, such as Figure 1 、 Figure 2 and Figure 4 As shown, it includes a distribution plate 1, a gas distribution pipe 4, a liquid distribution pipe 5 and a flow baffle 6.

[0037] The inner diameter of the distribution plate 1 is 0.2 mm smaller than the inner diameter of the packed tower. When installing the gas-liquid redistributor, it is horizontally and coaxially arranged within the tower, relative to the plane of the distribution plate 1. The distribution plate 1 is equipped with two types of uniformly distributed holes: large gas-distributing holes 3 and small liquid-distributing holes 2. As the gas flows upward from the lower packing layer in the tower, it is redistributed by the 12 gas-distributing holes 3, splitting it into smaller streams. The inner diameter of the gas-distributing holes 3 is 17% of the inner diameter of the packed tower, and the gas flow area is 25% of the packed tower cross-section. A larger gas flow area reduces flow resistance and pressure drop, thus preventing flooding at higher spray densities and significantly reducing costs. The liquid-distributing holes 2 have a diameter of 1.5 mm, providing a certain flow resistance. As the liquid flows downward from the upper packing layer in the tower, it is intercepted by the distribution plate 1, forming a liquid film. As the spray density increases, the liquid gradually accumulates on the surface of the distribution plate 1, forming a layer of liquid, which is then redistributed by the 13 liquid-distributing holes 2.

[0038] In order to facilitate the opening of holes and the uniform distribution of gas and liquid, the gas uniform distribution holes 3 and the liquid uniform distribution holes 2 are arranged in a circle with the center of the distribution plate 1 as the base point. The centers of the uniform distribution holes in each circle (the centers of the gas uniform distribution holes 3 and the liquid uniform distribution holes 2) are on the same circle, i.e. coaxial. The gas uniform distribution holes 3 and the liquid uniform distribution holes 2 are distributed alternately, and the spacing between adjacent circles of uniform distribution holes is fixed. Figure 2 As shown, the distribution plate 1 is provided with two circles of gas uniform distribution holes 3 and liquid uniform distribution holes 2, the outer circle is evenly spaced with 8 gas uniform distribution holes 3 and 8 liquid uniform distribution holes 2, the inner circle is evenly spaced with 4 gas uniform distribution holes 3 and 4 liquid uniform distribution holes 2, and the center of the distribution plate 1 is provided with a liquid uniform distribution hole 2, a total of 12 gas uniform distribution holes 3 and 13 liquid uniform distribution holes 2, so that the gas and liquid can be evenly distributed on the surface of the packing layer. At the same time, the outermost circle of liquid uniform distribution holes 2 is 12 mm away from the edge of the distribution plate 1, and the liquid distribution holes 2 on the outer circle and the liquid distribution holes 2 on the inner circle are staggered, so that the liquid is evenly distributed on the lower layer of packing, effectively avoiding the increase in liquid flow rate after re-concentration after expansion on the packing surface.

[0039] There are 12 gas distribution pipes 4 above the distribution plate 1 (that is, a gas distribution pipe 4 is provided on each gas uniform distribution hole 3). The bottom end of the gas distribution pipe 4 is fixedly connected to the distribution plate 1 by welding or other means, so that the gas distribution pipe 4 is connected to the gas uniform distribution hole 4. The distance from the center of the outer ring of gas uniform distribution holes 4 to the base point (the center of the distribution plate 1) is 85% of the radius of the distribution plate 1, which prevents the liquid on the tower wall from contacting the gas distribution pipe 4, and at the same time leaves space for the thickness of the gas distribution pipe 4. The thickness of the gas distribution pipe 4 is 0.5mm. The inner diameter of the gas distribution pipe 4 is equal to the inner diameter of the gas uniform distribution hole 3. A flow baffle 6 is provided at the upper end of the gas distribution pipe 4 to prevent the liquid from flowing into the gas distribution pipe 4 when flowing downward from the upper layer of filler in the tower. The sidewall of the flow baffle 6 is equipped with four symmetrically distributed vent holes 7. The area of these vent holes 7 is larger than the cross-sectional area of the gas distribution holes 3 to reduce gas flow resistance. Therefore, the larger the vent holes 7, the better. The area of all vent holes 7 is 1.25 times the cross-sectional area of the gas distribution holes 3 to reduce gas flow resistance. To maximize the area of the vent holes 7, they are rectangular, with a length-to-inner-diameter ratio of 0.7:1 and a height of 10 mm. In this embodiment, the gas distribution tube 4 and flow baffle 6 are integrally formed.

[0040] Thirteen liquid distribution pipes 5 are provided beneath the distribution plate 1, with one connected to each liquid distribution hole 2. The liquid distribution pipes 5 are cylindrical, with a larger outer diameter at the top than at the bottom. The thicker portion at the top is the upper end 51, while the thinner portion at the bottom is the drainage tube 52. The upper end 51 and the drainage tube 52 are integrally formed, with different wall thicknesses. The upper end 51 has an outer diameter of 5 mm, a thickness of 1.8 mm, and a length of 10 mm. The upper end 51 is fixedly connected to the bottom surface of the distribution plate 1 and communicates with the liquid distribution holes 2. Because the diameter of the liquid distribution holes 2 is too small, errors are inevitable when drilling. Therefore, the upper end 51 is used as a fixed end for connection to the liquid distribution holes 2 on the bottom surface of the distribution plate 1. It should be noted that the small end is a drainage tube 52, which has a thickness of 0.3 mm and an inner diameter of 1.4 mm. The inner diameter of the drainage tube 52 is smaller than the aperture of the liquid uniform distribution hole 2, and the length of the drainage tube 52 is 10 mm. By setting a reasonable number of drainage tubes 52, the liquid droplets are kept stable and evenly distributed. At low spray density, the liquid forms a liquid layer of a certain height on the upper part of the drainage tube 52 and on the surface of the distribution plate 1. The static pressure difference is used as the driving force to overcome the flow resistance within the drainage tube 52 and flow out of the outlet of the drainage tube 52. The inner diameter of the drainage tube 52 is very small, and the liquid flows slowly within the drainage tube 52. The flow rate at the outlet of each drainage tube 52 is stable and has little difference, thus achieving uniform distribution. The inner diameter of the drainage tube 52 is the key to uniform distribution of the liquid. When the inner diameter of the drainage tube 52 is too large, the liquid flow resistance is small and only part of the drainage tube 52 will have liquid flowing out, resulting in uneven liquid distribution. The smaller the inner diameter, the greater the resistance, the thicker the liquid layer formed, and the higher the redistributor height. This problem can be avoided by setting a reasonable number of drainage tubes 52, while maintaining stable and uniform distribution of droplets.

[0041] The gas-liquid redistributor of the utility model is applicable to a wide range of spraying densities, has a simple connection structure, high structural stability and low manufacturing cost.

[0042] Example 2: A gas-liquid redistributor for a small packed tower, such as Figure 3 As shown, it includes a distribution plate 1, a rubber ring 11, a gas distribution pipe 4, a liquid distribution pipe 5, a flow baffle 6, a liquid retaining groove 8 and a support ear 9.

[0043] The diameter of the distribution plate 1 in this embodiment is 0.5 mm smaller than the inner diameter of the packed tower. When installing the gas-liquid redistributor, it is horizontally and coaxially arranged in the tower with the plane of the distribution plate 1 as a reference.

[0044] To facilitate securing distribution plate 1 within the packed tower, a groove is provided around its outer circumference. A rubber ring 11 is secured within the groove. Rubber ring 11 fits over distribution plate 1 and within the groove, where it remains secure due to its elasticity. Once secured, the outer diameter of rubber ring 1 is slightly larger than the diameter of the plate, facilitating securement of the plate within the packed tower while preventing liquid from leaking through the gap between the plate and the packed tower.

[0045] In order to prevent liquid from leaking from the gap between the distribution plate 1 and the packing tower, a circle of liquid retaining grooves 8 is provided around the top edge of the distribution plate 1. The bottom of the liquid retaining grooves 8 is fixedly connected to the top edge of the distribution plate 1 by welding or other means. The height of the liquid retaining grooves 8 is less than the height of the gas distribution pipe 4, which is 40 mm, to accommodate a higher liquid layer.

[0046] The distribution plate 1 is equipped with two types of uniformly distributed holes: large holes for gas distribution 3 and small holes for liquid distribution 2. The arrangement of the gas and liquid distribution holes 3 and 2 on the distribution plate 1 is the same as in Example 1. The inner diameter of the gas distribution holes 3 is 20% of the inner diameter of the packed tower, and the gas flow area is 38% of the packed tower cross-section. The holes are 5 mm from the edge of the distribution plate 1 to prevent liquid from the tower wall from contacting the gas distribution pipe 4 and to allow for the thickness of the gas distribution pipe 4. The diameter of the liquid distribution holes 2 is 3 mm.

[0047] The gas distribution pipe 4, liquid distribution pipe 5, and flow baffles 6 are the same as those in Example 1. Unlike Example 1, each flow baffle 6 in the outermost ring is further provided with a lug 9 at the upper end of the outer wall. The lug 9 is fixedly connected to the flow baffle 6 and can also be installed as a support point on the corresponding lug of the packed tower. There are eight lugs 9, further improving installation convenience.

[0048] Finally, it should be noted that the above examples are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above examples and is subject to numerous variations. All variations that can be directly derived or conceived by a person skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A gas-liquid redistributor for a small packed tower, characterized in that: The distribution plate (1) comprises a gas uniform distribution hole (3) and a liquid uniform distribution hole (2), wherein the gas uniform distribution hole (3) has a larger aperture than the liquid uniform distribution hole (2); The gas uniform distribution holes (3) and the liquid uniform distribution holes (2) are arranged on different circles with the center of the distribution plate (1) as the center. On each circle, the gas uniform distribution holes (3) and the liquid uniform distribution holes (2) are alternately distributed, the spacing between two adjacent circles is equal, and the liquid uniform distribution holes (2) in two adjacent circles are staggered. A gas distribution pipe (4) is provided above the distribution plate (1), one gas uniform distribution hole (3) is connected to a gas distribution pipe (4), and the bottom end of the gas distribution pipe (4) is fixedly connected to the top surface of the distribution plate (1); A liquid distribution pipe (5) is provided below the distribution plate (1), and a liquid uniform distribution hole (2) is connected to a liquid distribution pipe (5). The liquid distribution pipe (5) comprises an upper end cap (51) and a lower drainage pipe (52). The upper end cap (51) and the drainage pipe (52) are integrally formed. The upper end cap (51) is fixedly connected to the bottom surface of the distribution plate (1), and the inner diameter of the drainage pipe (52) is smaller than the aperture of the liquid uniform distribution hole (2).

2. A gas-liquid redistributor for a small packed tower according to claim 1, characterized in that: A flow baffle (6) is provided at the upper end of the gas distribution pipe (4), and four symmetrically distributed vent holes (7) are provided on the side wall of the flow baffle (6), and the vent holes (7) are rectangular.

3. A gas-liquid redistributor for a small packed tower according to claim 2, characterized in that: The distance between the center of the gas uniform distribution hole (3) in the outer ring and the center of the distribution plate (1) is 70-85% of the radius of the distribution plate, the number of the gas uniform distribution holes (3) is at least 4, and the aperture of the gas uniform distribution hole (3) is 7-23% of the inner diameter of the packing tower.

4. A gas-liquid redistributor for a small packed tower according to claim 3, characterized in that: The diameter of the liquid uniform distribution holes (2) is 1 to 10 mm, and the number of the holes is at least 4.

5. The gas-liquid redistributor for a small packed tower according to claim 4, characterized in that: The outer diameter of the upper end (51) is 1 to 10 mm, the thickness is 0.2 to 3 mm, and the length is 5 to 30 mm. The outer diameter of the upper end (51) is larger than the inner diameter of the drainage tube (52). The drainage tube (52) has an inner diameter of 0.5 to 2 mm, a thickness of 0.1 to 0.5 mm, and a length of 5 to 20 mm.

6. The gas-liquid redistributor for a small packed tower according to claim 5, characterized in that: The area of the vent hole (7) is greater than or equal to 1.2 times the cross-sectional area of the gas distribution hole (3).

7. A gas-liquid redistributor for a small packed tower according to any one of claims 1 to 6, characterized in that: The distribution plate (1) is provided with a circle of grooves on its outer circumference, and the rubber ring (11) is sleeved in the grooves; a circle of liquid retaining grooves (8) is provided around the edge of the top surface of the distribution plate (1), and the liquid retaining grooves (8) are fixedly connected to the distribution plate (1), and the height of the liquid retaining grooves (8) is less than the height of the gas distribution pipe (4).

8. The gas-liquid redistributor for a small packed tower according to claim 7, characterized in that: The baffle (6) on the outer ring of the gas distribution pipe (4) is provided with a support ear (9), which is located at the upper end of the baffle (6) and fixedly connected to the side wall of the baffle (6).

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