Composite structured packing for supergravity cross-flow rotating bed and application of composite structured packing

Abstract

The invention discloses composite structured packing for a supergravity cross-flow rotating bed and application of the composite structured packing, and belongs to the technical field of chemical equipment packing. According to the structure of the packing, an upper structured packing, a middle structured packing and a lower structured packing are stacked in the axial direction to form different gas-liquid phase channels, the upper-layer packing is of a demisting structure, the lower-layer packing and the middle-layer packing are each composed of a filling structure and a net-shaped structure, and the inclination directions of the filling structures in the lower-layer packing and the middle-layer packing are opposite. A circle of axial-flow type blades are embedded in the lower-layer filler close to the inner edge; the filling structure is a frame structure composed of triangular unit bodies, and the frame structure is evenly distributed in the circumferential direction and arranged in a staggered mode in the axial direction. The net-shaped structure comprises transverse wires and longitudinal wires, and the net-shaped structure and the filling structure are arranged at intervals in the radial direction. Three specific gas-liquid phase channels are designed, and the gas-liquid flowing direction is changed for multiple times, so that multiple changes of the axial speed and direction of gas and uniform distribution of the gas in the filler are effectively realized; the structured packing has a demisting function, and liquid foam entrainment is effectively reduced.

Description

Technical Field

[0001] The present invention relates to a composite structured packing for a high gravity cross-flow rotating bed and its application, belonging to the technical field of chemical equipment packing. Background Technique

[0002] Since the advent of high gravity technology, it has been favored by people due to its enhanced effect in gas-liquid mass transfer, especially in the field of chemical process intensification, and has received extensive attention. High gravity devices have achieved great success in mass transfer, separation, reaction, absorption, etc. due to their advantages such as small volume, high mass transfer efficiency, low energy consumption, environmental friendliness, and convenient installation and maintenance. The core of a high gravity device is a rotating packing bed. Compared with traditional tower equipment, the reaction in the rotating packing bed is a fast reaction, and gas-liquid contact and reaction can be completed in only a few milliseconds. The volumetric mass transfer coefficient can be increased by 1-3 orders of magnitude compared with tower equipment, and its volume is only one fortieth of that of tower equipment. High gravity technology has unique advantages in the chemical industry.

[0003] As the core component of the rotating bed, the packing is the main place where efficient mixing of materials and micro mass transfer reactions occur. The characteristics of the packing play a decisive role in the overall performance of the equipment. The structure of the packing determines the mass transfer and hydrodynamics performance of the high gravity device, as well as the stability and service life of the device. The packing can be divided into two categories: random packing and structured packing. Random packing is randomly stacked packing, which is easy to move circumferentially under the rotating action, forming a phenomenon of "sparse inside and dense outside", which is not conducive to gas-liquid mass transfer; structured packing has good uniformity and symmetry, and can still achieve the shearing and coalescence effects of gas-liquid phases during high-speed rotation. It is not difficult to see that the research and development of new structured packing is of great significance for improving the performance of the rotating packing bed. The surface modification of the packing, the structure of the packing, the manufacturing technology, and the installation method, etc. will all affect the mass transfer and hydrodynamics performance of the packing. Among them, the structure of the packing has the most obvious influence on the mass transfer and hydrodynamics performance of the rotating bed, and the performance improvement of the high gravity device can be achieved by changing the structure of the packing.

[0004] The ideal packing should have high mass transfer efficiency and low pressure drop, which can be considered from two aspects: gas phase and liquid phase. First, from the gas phase aspect: Liang Pengfei (Liang Pengfei. Research and Performance Study on 3D Printed New Structured Packings for Rotating Packed Beds [D]. Journal of North University of China, 2018.) combined the droplet dispersion performance of wire mesh packing and the advantages of low-pressure drop packing, and used 3D printing technology to construct a new structured packing with a large number of regular gas and liquid phase channels. The 3D printed new packing can achieve good mass transfer effect while significantly reducing the pressure drop. However, its structure is relatively single and the degree of disturbance to the gas phase is small. In 2021, Duan (Chemical Engineering and Processing - Process Intensification, 2021, 161.) studied the influence of the axial height and distribution of the packing stator and rotor on the gas phase volume mass transfer coefficient of a multi-stage cross-flow rotating packed bed. The results showed that in the reaction controlled by the gas film, the packing stator can enhance gas disturbance, and the gas turbulence effect region is located in the region where the gas just enters the packing layer. Therefore, increasing the number of mutations in the axial channel structure of the gas can increase the gas turbulence effect region in the packing. In 2014, Wu Yi (Wu Yi. Structural Design and Flow Field Simulation Study on Cross-Flow Rotating Packed Bed [D]. Southwest Petroleum University, 2014.) simulated and analyzed the macroscopic flow of gas-liquid two-phase flow in a cross-flow rotating packed bed by CFD simulation technology. The results showed that the gas holdup first increases and then decreases radially in the packing, and the gas holdup in the inner region first decreases and then increases with the axial height, while the opposite is true in the outer region. It can be seen that the gas distribution in the packing is not uniform, and the gas holdup in the central region of the packing is relatively low.

[0005] Secondly, in terms of the liquid phase: Wen Zhang (Chemical Engineering Science. 2022. 248: 117147.) studied the wire diameter and shape of wire mesh packing. Elliptical wires have a stronger carrying effect on liquid droplets, while diamond-shaped wires have a stronger cutting effect on liquid droplets. However, liquid droplet back-splashing is likely to occur at high rotational speeds. This is because streamline shapes can delay boundary layer separation, and surfaces with sharp corners tend to cause premature boundary layer separation. Therefore, while retaining the above advantages and increasing the surface area of the wire diameter, the specific surface area of the packing can be further increased. Zhang et al. (Chemical Engineering Journal, 2022. 427: 130874.) studied the flow patterns of liquids in three-dimensional CFD-simulated structured wire mesh packing. The research results show that most of the flow patterns at the inner edge of the packing area are film flow and pore flow, while most of the flow patterns at the outer edge are droplet flow. The contact area between the liquid and the wire mesh at the inner edge of the packing is relatively large, giving the liquid a relatively large circumferential kinetic energy and increasing the circumferential velocity of the liquid. While the liquid density at the outer edge of the packing is relatively small, and the contact probability with the wire mesh is low, so the liquid will maintain its original flow direction. It can be seen that the size of the liquid droplets in the packing gradually decreases along the radial direction, and the effect of the outer edge of the packing on liquid droplet dispersion is weaker than that of the inner edge.

[0006] On the other hand, when gases and liquids come into contact in a cross-flow rotating packed bed, it is usually accompanied by the splashing and dispersion of liquid particles. As the gas flow rate increases, these small liquid droplets will be entrained and discharged with the gas stream, affecting the purity of the gas-phase product. At the same time, in industrial applications, cross-flow rotating packed beds with high gravity usually involve the treatment of large gas and liquid flows. The entrained liquid droplets may accumulate and block in the system, resulting in unstable operation of subsequent equipment and even potential safety hazards. Combining the design ideas of gas and liquid phases, there is an urgent need to design a composite packing that can meet the requirements of high mass transfer efficiency, low pressure drop performance, and the reduction of gas entrained liquid droplets. Summary of the Invention

[0007] The present invention aims to provide a composite structured packing for a high-gravity cross-flow rotating bed and its application. In view of the special structure of the gas-liquid phase channels inside the packing, a structured packing model is designed using 3ds Max three-dimensional modeling software. Two types of structured gas channels, a liquid phase channel composed of circular wires and water droplet-shaped wires, and a unique demisting structure are constructed inside the packing; this can effectively achieve multiple changes in the axial velocity of the gas and the uniform distribution of the gas in the packing, while reducing the phenomenon of gas entrained liquid droplets and ensuring the purity of the gas product.

[0008] The present invention designs a packing model using 3ds Max software and prints out a solid packing using 3D printing technology. The printed packing has specific gas-liquid channels and disturbance structures, and meets the requirements of high mass transfer efficiency, low pressure drop performance, and the ability to reduce the phenomenon of gas entraining liquid droplets. The packing design is considered from two aspects: gas phase and liquid phase. In terms of the gas phase, the turbulent effect area of the gas is concentrated in the lower part of the packing where the gas just enters, because the relative slip velocity between the gas and the packing is large, and the turbulent effect area is beneficial to improving the mass transfer efficiency. Based on this, in the present invention, three different packings of upper, middle, and lower are axially stacked, and when the gas passes through the packing body axially from bottom to top, it will experience different degrees of disturbance every time it passes through a kind of packing, increasing the turbulent effect area in the packing. In the cross-flow rotating packing, the gas holdup at the outer edge is higher than that at the inner edge, and the gas distribution is not uniform. Based on this, the present invention embeds an axial-flow fan structure at the inner edge of the lower layer of the packing, which has a pressurizing effect on the gas during rotation, reduces the gas phase pressure drop, avoids the need for an additional fan, and at the same time the gas is more likely to enter from the inner edge of the packing, and the gas distribution is more uniform. In terms of the liquid phase, the liquid distributor evenly sprays the liquid at the inner edge of the center of the packing layer. The high-speed rotating packing brings a strong shearing force, and the liquid is sheared and dispersed into fine micro-elements in the packing. Its dispersion effect determines the gas-liquid contact area and time, thus affecting the mass transfer performance. However, when constructing the liquid phase flow channel, the flow characteristics of the gas phase fluid in the equipment should be considered. Based on this, the present invention installs a mesh structure and a filling structure in the lower and middle layer packings. The gas spirally ascends along the filling structure, and the staggered arrangement between the filling structure layers causes the gas to be dispersed and coalesced multiple times. The liquid collides with the mesh structure, and different wire diameter combinations enhance the radial dispersion of the liquid. The centrifugal force causes some liquid to collide with the filling structure unit body, realizing multiple rapid dispersions-coalescences-dispersions of the liquid, increasing the gas-liquid contact area and time. However, in the cross-flow rotating packing bed, there is usually a phenomenon of gas entraining liquid droplets, which affects the purity of the gas phase product; at the same time, the untreated liquid droplets may accumulate and block the subsequent equipment and pipelines in the system, resulting in unstable operation of the equipment and even potential safety hazards; based on this, the upper layer packing of the present invention is a demisting structure, and no liquid is sprayed on this layer, that is, there is no need to consider the liquid phase channel. When the gas passes through this layer of packing axially, due to inertia, the water mist in the gas impacts the baffle surface and coalesces and aggregates in the tiles. Then, due to the action of centrifugal force, the liquid droplets are thrown out radially outward, and gradually grow and converge on the cylinder wall and flow into the middle packing layer for secondary reaction, reducing the liquid droplet entrainment and ensuring the gas phase purity and equipment safety.

[0009] The present invention provides a composite structured packing for a high-gravity cross-flow rotating bed, which includes upper, middle, and lower packing layers. That is, the packing design changes from an integral structure to a layered structure, with three different structured packings, namely upper, middle, and lower ones, axially superimposed to form different gas-liquid channels. The upper-layer packing is a demisting structure, and the lower-layer packing and the middle-layer packing are composed of a filling structure and a mesh structure. The inclination directions of the filling structures in the lower and middle layers are opposite, and an axial-flow blade structure is inlaid in a circle at the inner edge of the lower-layer packing, which has a pressurizing effect, reduces the gas-phase pressure drop, and avoids the need for an additional fan.

[0010] The filling structure is composed of a frame structure formed by triangular unit bodies, which are superimposed up and down at an inclination of 30° to 60°, evenly distributed in the circumferential direction and staggered in the axial direction.

[0011] The horizontal and vertical filaments of the mesh structure are respectively composed of circular-section filaments (horizontal filaments) and water-drop-shaped filaments (vertical filaments), and are arranged at intervals in the radial direction with the filling structure.

[0012] The axial-flow blade structure is inlaid in the lower-layer packing at the inner edge of the packing. In the filling structure with the axial-flow blades added, the spacing between triangular unit bodies is twice that in other circles (i.e., the axial-flow blades are inserted into the filling structure).

[0013] The upper-layer packing is a demisting structure and does not spray liquid. It is composed of inclined baffles, a cylinder, and tile structure plates. The cylinder has 3 to 20 circles and is arranged in a concentric circle manner. The inclined baffle is a fan-shaped structure, with two straight sides and one arc side. The inclined baffles are installed in the same radial direction. The intersection of the two straight sides (the apex angle of the fan-shaped structure) is connected to the inner cylinder, and the arc side is connected to the outer cylinder. They are evenly distributed at intervals of 12° to 36° in the circumferential direction. The included angle between the inclined baffle and the horizontal plane is 40° to 60°, and its circumferential inclination direction is the same as the rotor rotation direction. Tile structure plates are installed alternately on the upper and lower sides of the inclined baffle, so that the baffle structures between adjacent inclined baffles do not affect each other and are evenly arranged. The tile thickness is 1 to 3 mm, the length is less than that of the inclined baffle, and the height is 1 / 2 of the inclined baffle spacing. One of its sides is inserted into the inclined baffle structure, and the formed groove direction is opposite to the gas flow direction (the gas flow direction is from bottom to top). The groove width is about 6 mm, and the installation direction is the same as the packing radial direction.

[0014] A composite structured packing for a high gravity cross-flow rotating bed provided by the present invention designs a structured packing model using 3ds Max 3D modeling software. In the gas phase direction, gas enters from below the packing and flows out from above. In the liquid phase direction, liquid flows out radially from the inner side of the center of the packing to the outside, and is dispersed and coalesced by the packing multiple times during the process of passing through the packing. For the gas phase direction, two channels spiraling upward in opposite directions are constructed inside the packing, and an axial flow blade structure is added to pressurize the gas, reduce the gas phase pressure drop, avoid the need for an additional fan, and at the same time make the gas flow evenly distributed in the packing. For the liquid phase direction, a network structure with the cross-sectional shapes of the horizontal and vertical filaments being circular filaments (horizontal filaments) and water droplet-shaped filaments (vertical filaments) respectively is constructed, which forms multiple rapid and violent dispersions and coalescences of the liquid phase with the upward-spiraling channel structure in the gas phase direction. And a unique demisting structure is constructed to efficiently capture fine liquid droplets and mist in the gas phase, thereby improving the purity of the gas product and the operation safety of the equipment.

[0015] The filling structure is installed in the middle and lower layers of the packing. The frame structure composed of triangular unit bodies is evenly distributed in the circumferential direction and staggered in the axial direction. Moreover, the inclination directions of the filling structures in the lower and middle layers of the packing are opposite, increasing the probability of liquid droplet dispersion and coalescence while constructing a spiral gas channel, increasing the gas turbulence, and improving the turbulent effect area in the packing. The frame structure composed of triangular unit bodies is formed by superimposing two "×"-shaped structures inclined at a certain angle up and down, and the included angle with the horizontal direction is between 30° and 60°. Its six vertices are embedded in the horizontal filaments of the network structure for fixation, and are evenly arranged at intervals of 4 mm to 10 mm in the circumferential direction, and then each layer is staggered in the axial direction to form the same height as the network structure.

[0016] The horizontal and vertical filaments of the network structure are respectively composed of circular filaments (horizontal filaments) and water droplet-shaped filaments (vertical filaments) with cross-sectional shapes, increasing the cutting effect on liquid droplets and at the same time increasing the specific surface area of the packing. The diameter of the water droplet-shaped filament is composed of an isosceles triangle and an arc, and the two equal sides in the triangle are tangent to the arc. The length and width of the water droplet-shaped filament and the diameter of the circular filament have a difference of no more than 5 mm and are not less than 1 / 2 of the diameter of the circular filament.

[0017] The axial flow blade structure forms a low-pressure area at the inner edge of the packing when the packing rotates, and the gas will be sucked in and then enter the packing along the axis, making the gas evenly distributed in the packing and at the same time increasing the coalescence efficiency of liquid droplets in the packing. For the axial flow blade structure, the length, width, and height of the cube occupied by the whole fan blade are 10 - 30 mm, and they are evenly distributed in the circumferential direction, with 9 - 27 pieces. The axial flow blade structure is inlaid in the lower layer of the packing, and the position is in the 3rd to 10th circles counted from the inside to the outside in the radial direction. The distance between the triangular unit bodies in the filling structure between the blades is twice that in other circles.

[0018] The construction method of the above structured packing is as follows: First, use 3ds Max software to design a structured packing model. Utilize the freedom of the software design to design the mesh structure, filling structure, axial flow blade structure, and demisting structure required for the three-dimensional packing model. Based on the mesh structure and filling structure as basic units, construct the lower-layer packing and the middle-layer packing, and set the axial flow blade structure in the lower-layer packing. Finally, construct the upper-layer packing structure. Stack the three types of packings axially to form a complete packing structure, and use 3D printing technology to print out the solid packing.

[0019] The technical solution adopted by the present invention to solve its technical problems is that the lower-layer packing and the middle-layer packing are composed of a filling structure and a mesh structure. The filling structure consists of a frame structure composed of inclined triangular unit bodies, which are evenly distributed circumferentially and staggered axially. Moreover, the inclination directions of the filling structures in the lower layer and the middle layer are opposite, thereby increasing the number of sudden changes in the gas flow direction. The mesh structure is composed of circular wires and water-drop-shaped wires, increasing the specific surface area of the wire diameter and the liquid droplet dispersion effect. A ring of axial flow blade structures is inlaid at the inner edge of the lower-layer packing, which has a pressurizing effect on the gas, reduces the gas-phase pressure drop, avoids the need for an additional fan, and at the same time, the gas is more likely to enter from the inner edge of the packing, and the gas distribution is more uniform. The upper-layer packing is a demisting structure, without liquid spraying, and is composed of an inclined baffle structure, a cylinder, and a tile structure plate. The two rings of inclined baffle structures are fixed by two rings of cylinders, and the tile structure plates are installed staggered above and below the inclined baffle, so that the baffle structures in the gaps between adjacent inclined baffles do not affect each other and are evenly arranged. The gas passes through the first two types of packings axially, mixes in the gaps and then enters the upper-layer packing. Due to inertia, the water mist in the gas impacts the baffle surface and is collected in the tile structure plate. Then, due to the action of centrifugal force, the liquid droplets are thrown out radially along the blade surface of the baffle, and gradually grow while being thrown out. After hitting the wall of the cross-flow rotating packing bed or the cylinder wall, they flow down into the middle-layer packing, thereby reducing the liquid droplet entrainment phenomenon. After the model is constructed, use 3D printing technology to print out the solid model. The composite structured packing described in the present invention can effectively realize multiple changes in the axial velocity and direction of the gas, as well as the uniform distribution of the gas in the packing, while reducing the gas entrainment of liquid droplets and ensuring the purity of the gas-phase product.

[0020] The present invention provides the application of the above composite structured packing for a high-gravity cross-flow rotating bed in a rotating packing bed:

[0021] This structured packing is applied in a cross-flow rotating packing bed device, which includes a fan, a cross-flow rotating packing bed, a motor, a recycled liquid storage tank, a raw material liquid storage tank, and a centrifugal pump. The bottom side of the cross-flow rotating packing bed is provided with a gas inlet, and the top is provided with a liquid inlet. A liquid distributor is provided at the bottom of the liquid inlet pipe, and the outlet of the liquid distributor is arranged facing the packing rotor. The bottom of the packing rotor is connected to the motor. One side of the top of the cross-flow rotating packing bed is provided with a gas outlet, and one side of the bottom is provided with a liquid outlet, and the liquid outlet is connected to the recycled liquid storage tank. The gas-liquid contact process is as follows: The gas phase enters from the gas inlet at the bottom of the packing and axially passes through the packing from bottom to top; the liquid phase enters from the liquid inlet and radially passes through the packing from inside to outside through the liquid distributor, and the gas-liquid two phases are in staggered contact, mixing and reacting in the packing. After the reaction is completed, the gas-liquid two phases are discharged from the gas outlet and the liquid outlet respectively.

[0022] The axial-flow blades are structures for disturbing, entraining gas and coalescing liquid in the packing and are present in the lower layer of the packing. The gas enters from the gas inlet. Due to the characteristics of the axial-flow blades, they have a pressure-boosting effect on the gas during rotation, reducing the gas-phase pressure drop and avoiding the need for an additional fan. At the same time, the gas is more likely to enter from the inner edge of the packing, and the gas distribution is more uniform. The liquid is dispersed radially into the packing layer under the action of the distributor and is divided into tiny liquid films, liquid filaments and liquid droplets due to the centrifugal force, and then is aggregated by the packing and the blades.

[0023] The mesh structure and the filling structure are structures for dispersing and coalescing the gas-liquid two phases in the packing and are present in the lower and middle layers of the packing. The gas entering from the gas inlet at the bottom of the packing first contacts the lower layer of the packing. The inclination direction of the filling structure is the same as the rotation direction of the rotating packing bed, which is beneficial to the gas entering the packing. In the filling structure inlaid with axial-flow blades, the spacing between the triangular unit bodies is twice that in other layers, making it easier for the gas to enter from the inner edge of the packing and evenly distributing the gas in the packing. The channels in the filling layer are inclined and staggered between layers, causing the gas to be shunted and mixed with the gas in the channels of the adjacent lower filling layer, having a blocking and mixing effect. Macroscopically, the gas spirally rises along the channels, and the gas flow direction suddenly changes at the junction of the two packings, and the gas turbulence degree increases. The liquid enters the packing radially under the action of the distributor and first enters the mesh structure. The structure with different wire diameter combinations increases the degree of liquid dispersion in the radial direction. After the liquid droplets pass through the mesh structure, due to the centrifugal force of the rotating bed, part of the liquid moves in a circular motion under the centrifugal force and will collide with the triangular unit bodies of the filling structure in the circumferential direction again, further dispersing the liquid in the circumferential direction, increasing the number of times of liquid dispersion in the circumferential direction and the residence time of the liquid in the packing layer.

[0024] The demisting structure is the upper packing, which reduces the liquid entrainment phenomenon. The gas passes through the first two packings axially, mixes in the gap and then enters the upper packing. The inclined baffle changes the gas velocity and direction, increasing the gas turbulence degree. No liquid is sprayed in this layer. The gas carrying water mist enters the baffle gap after hitting the surface of the inclined baffle axially from bottom to top due to inertia. The liquid droplets will gather inside the staggered tile-shaped structure and flow down to the middle packing layer after being thrown out along the radial blade surface. In this process, the small liquid droplets slowly coalesce into larger ones, thus greatly reducing the entrainment of liquid droplets and liquid foams and ensuring the purity of the gas-phase product and the operation safety of the equipment.

[0025] Advantages of the present invention:

[0026] (1) In the present invention, the research and development of the packing is changed from the overall structure modification to the fine design of the gas-liquid phase channels inside the packing. By designing three specific gas-liquid phase channels and changing the gas-liquid flow directions multiple times, the multiple changes of the axial velocity and direction of the gas and the uniform distribution of the gas in the packing can be effectively realized.

[0027] (2) The structured packing of the present invention has a demisting function, which can effectively reduce the phenomenon of gas entraining liquid foam in the cross-flow rotating packed bed and ensure the purity of the gas-phase product.

[0028] (3) By using 3D modeling software and 3D printing technology, the limitations in the traditional array-type packing design are broken, providing a new idea and direction for the design and development of new packings, and further promoting the development of the supergravity technology. Description of the Drawings

[0029] Figure 1 It is a schematic diagram of the shape of the mesh structure; A is the cross-sectional shape of the circular wire, B is the cross-sectional shape of the water-drop-shaped wire, C is the combined structure of several horizontal wires, D is the mesh structure (single ring structure) formed by the combination of horizontal and vertical wires, and E is the combined schematic diagram of multiple mesh structures (multiple cylindrical structures);

[0030] Figure 2 It is a schematic diagram of the filling structure unit and its arrangement; A is the frame formed by connecting the triangular vertices and sides in sequence as the filling structure unit, B is the filling structure formed by combining multiple units (rotating counterclockwise); C is the filling structure with the opposite inclination direction to B;

[0031] Figure 3 It is a schematic diagram of the axial-flow blade structure and its installation position; A is the single blade structure, B is the structure formed by multiple blades surrounding a circle, C is the combined schematic diagram of the blade and the filling structure; D is the schematic diagram of the filling structure of a single cylinder with a large spacing (leaving space for the axial-flow blade structure);

[0032] Figure 4Schematic three-dimensional structure diagram of a single inclined baffle and a cylinder;

[0033] Figure 5 Schematic structure diagram of the upper packing;

[0034] Figure 6 Top view schematic diagram of the upper packing;

[0035] Figure 7 Schematic diagram of the actual shape and calculation method of the inclined baffle;

[0036] Figure 8 Schematic diagram of the morphology and installation position of the tile structure plate; A is the tile structure plate, B is the combined plate structure of the tile structure plate and the inclined baffle, C is the structure diagram of two adjacent combined plates; D is the three-dimensional structure diagram of the upper packing;

[0037] Figure 9 Schematic diagram of the complete three-dimensional composite structured packing;

[0038] Figure 10 Schematic diagram of the structured packing applied to the cross-flow rotating packing bed.

[0039] In the figure, 1 is the fan, 2 is the gas inlet, 3 is the cross-flow rotating packing bed, 4 is the liquid inlet, 5 is the liquid distributor, 6 is the packing rotor, 7 is the gas outlet, 8 is the liquid outlet, 9 is the motor, 10 is the recovered liquid storage tank, 11 is the centrifugal pump, and 12 is the raw material liquid storage tank. Detailed implementation manners

[0040] The present invention will be further described below through embodiments, but is not limited to the following embodiments.

[0041] Embodiment 1:

[0042] This embodiment provides a composite structured packing for a high-gravity cross-flow rotating bed, as Figures 1 - 10 shown, including upper, middle, and lower three packing layers, that is, the packing design changes from an integral structure to a layered structure, and three different structured packings of upper, middle, and lower are axially stacked to form different gas-liquid channels. The upper packing is a demisting structure, and the lower packing and the middle packing are composed of a filling structure and a mesh structure. The inclination directions of the filling structures in the lower and middle packings are opposite, and an axial flow blade structure is inlaid in a circle at the inner edge of the lower packing, which has the function of boosting pressure, reducing the gas-phase pressure drop, and avoiding the need for an additional fan.

[0043] The filling structure is a frame structure composed of triangular unit bodies, which are stacked up and down at an inclination of 30° to 60°, and are evenly distributed in the circumferential direction and staggered in the axial direction. The filling structure unit body and its arrangement are as Figure 2As shown in the figure; A is a frame formed by connecting the top angles and sides of triangles in a top-angle-to-top-angle and side-to-side sequence as a filling structural unit body, B is a filling structure composed of multiple unit bodies (rotated counterclockwise); C is a filling structure with an inclination direction opposite to that of B.

[0044] The horizontal and vertical filaments of the mesh structure are respectively composed of circular filaments (horizontal filaments) and water-drop-shaped filaments (vertical filaments) in terms of cross-sectional shape, and are arranged at a radial interval from the filling structure. The mesh structure is shown in Figure 1 the figure; A is the cross-sectional shape of the circular filament, B is the cross-sectional shape of the water-drop-shaped filament, C is the combined structure of several horizontal filaments, D is the mesh structure composed of horizontal and vertical filaments (a single ring structure), E is the combined schematic diagram of multiple mesh structures (multiple cylindrical structures);

[0045] The axial-flow blade structure is embedded in the lower filler, and the position is at the inner edge of the filler. In the filling structure with the axial-flow blade added, the spacing between triangular unit bodies is twice that in other layers (i.e., the axial-flow blade is inserted into the filling structure). The axial-flow blade structure and the installation position are as shown in Figure 3 the figure; A is a single axial-flow blade structure, B is the structure formed by multiple blades enclosing a circle, C is the combined schematic diagram of the blade and the filling structure; D is the schematic diagram of the filling structure of a single cylinder with a large spacing (leaving space for the axial-flow blade structure);

[0046] The upper filler is a demisting structure and does not spray liquid, and is composed of inclined baffles, cylinders, and tile structure plates. There are 3 to 20 circles of cylinders, arranged in a concentric circle manner. The inclined baffle is a fan-shaped structure, with two straight sides and one arc side. The inclined baffles have the same installation direction in the radial direction. The intersection of the two straight sides (the top angle of the fan-shaped structure) is connected to the inner cylinder, and the arc side is connected to the outer cylinder. They are evenly distributed at a circumferential interval of 12° to 36°. The angle between the inclined baffle and the horizontal plane is 40° to 60°, and its circumferential inclination direction is the same as the rotation direction of the rotating packing bed. Tile structure plates are installed staggeredly on the upper and lower sides of the inclined baffle, so that the baffle structures between adjacent inclined baffles do not affect each other and are evenly arranged. The tile thickness is 1 to 3 mm, the length is less than the length of the inclined baffle, and the height is 1 / 2 of the spacing between the inclined baffles. One of its sides is inserted into the inclined baffle structure, and the formed groove direction is opposite to the air flow direction (the air flow direction is from bottom to top), and the groove width is about 6 mm, and the installation direction is the same as the radial direction of the filler. The morphology and installation position of the tile structure plate are as shown in Figure 8 the figure; A is the tile structure plate, B is the combined plate structure of the tile structure plate and the inclined baffle, C is the combined structure diagram of two adjacent combined plates; D is the three-dimensional structure schematic diagram of the upper filler.

[0047] A composite structured packing for a high-gravity cross-flow rotating bed provided by the present invention designs a structured packing model using 3ds Max 3D modeling software. In the gas phase direction, gas enters from below the packing and flows out from above. In the liquid phase direction, liquid flows out radially from the inner side of the center of the packing to the outside, and is dispersed and coalesced by the packing multiple times during the process of passing through the packing. For the gas phase direction, two channels spiraling upward and in opposite spiral directions are constructed inside the packing, and an axial flow blade structure is added to pressurize the gas, reduce the gas phase pressure drop, avoid the need for an additional fan, and at the same time make the gas flow evenly distributed in the packing. For the liquid phase direction, a network structure with the cross-sectional shapes of the horizontal and vertical filaments being circular filaments (horizontal filaments) and water droplet-shaped filaments (vertical filaments) respectively is constructed, which forms multiple rapid and intense dispersions and coalescences of the liquid phase with the upward spiral channel structure in the gas phase direction. And a unique demisting structure is constructed to efficiently capture fine liquid droplets and mist in the gas phase, thereby improving the purity of the gas product and the operation safety of the equipment.

[0048] The filling structure is installed in the middle and lower layers of the packing. The frame structure composed of triangular unit bodies is evenly distributed in the circumferential direction and staggered in the axial direction. Moreover, the inclination directions of the filling structures in the lower layer and the middle layer of the packing are opposite, increasing the probability of liquid droplet dispersion and coalescence while constructing a gas phase spiral channel, increasing the gas turbulence, and improving the turbulent effect area in the packing. The frame structure composed of triangular unit bodies is formed by superimposing two "×"-shaped structures inclined at a certain angle up and down, and the angle with the horizontal direction is between 30° and 60°. Its six vertices are embedded in the horizontal filaments of the network structure for fixation, and are evenly arranged at intervals of 4 mm to 10 mm in the circumferential direction, and then each layer is staggered in the axial direction to form the same height as the network structure.

[0049] The horizontal and vertical filaments of the network structure are respectively composed of circular filaments (horizontal filaments) and water droplet-shaped filaments (vertical filaments) with cross-sectional shapes, increasing the cutting effect on liquid droplets and at the same time increasing the specific surface area of the packing. The diameter of the water droplet-shaped filament is composed of an isosceles triangle and an arc, and the two equal sides in the triangle are tangent to the arc. The length and width of the water droplet-shaped filament and the diameter of the circular filament have a difference of no more than 5 mm and are not less than 1 / 2 of the diameter of the circular filament.

[0050] The axial flow blade structure forms a low-pressure area at the inner edge of the packing when the packing rotates, and the gas will be sucked in and then enter the packing axially, making the gas evenly distributed in the packing and at the same time increasing the coalescence efficiency of liquid droplets in the packing. For the axial flow blade structure, the length, width, and height of the cube occupied by the whole fan blade are 10 - 30 mm, and they are evenly distributed in the circumferential direction, with 9 - 27 pieces. The axial flow blade structure is embedded in the lower layer of the packing, and the position is in the 3rd to 10th circles counted from the inside to the outside in the radial direction. The distance between the triangular unit bodies in the filling structure between the blades is twice that in other circles.

[0051] The specific construction method of the above composite structured packing is as follows:

[0052] Use 3ds Max 3D modeling software to construct structured packing. The net-like structural unit is composed of circular wires and water-drop-shaped wires. Different combinations of wire diameters increase the radial dispersion degree of the liquid. The diameter d of the circular wire is 0.5 - 2 mm, as shown in Figure 1 A, and the diameter of the water-drop-shaped wire is as shown in Figure 1 B. The approximate dimensions (described with a triangle at the top and an arc at the bottom) are: composed of an isosceles triangle with a base angle of 53° and a vertex angle of 74° and an arc with a diameter of 1.2d. Among them, the two equal sides in the triangle are tangent to the arc, forming a water-drop-shaped wire diameter with a length of (1.6 - 2)d and a width of (1.2 - 1.6)d. The horizontal wires are circular wires, and the radius of the innermost circle is (30 - 50)d. They are arranged at an axial interval of (2 - 6)d, with a total of 18 layers, as shown in Figure 1 C; the vertical wires are water-drop-shaped wires, and the vertices of the triangles face the center of the circle (the liquid droplet incident direction) and are evenly distributed at a certain circumferential interval. The combination of horizontal wires and vertical wires forms a frame structure with square holes, forming a single-loop net-like structure, as shown in Figure 1 D. Then they are arranged at a consistent radial interval, with an interval of (3 - 8)d, as shown in Figure 1 E, with a total of 11 loops. The intervals between the vertical wires of the single-loop net-like structure are (3 - 6)d for the first three loops from the inside to the outside in the radial direction, (4 - 6)d for the middle four loops, and (2 - 4)d for the outermost four loops, finally forming the overall net-like structure as shown in Figure 1 E.

[0053] The filling structure is composed of a frame structure formed by triangular unit bodies, which are inclined at 30° - 60° and evenly distributed in the circumferential direction, and are arranged staggeredly in the axial direction, forming a spiral gas phase channel macroscopically (the gas flows in the gaps between the triangular unit bodies). Among them, the frame structure composed of triangular unit bodies is composed of two "×"-shaped structures tilted at a certain angle and superimposed up and down, as shown in Figure 2 A. The overall width occupied by the three-dimensional space is (3 - 8)d, and the length is (6 - 12)d. The angle between this structure and the radial plane is about 34°, and a1 - c2 are fixed by three layers of circular wires (horizontal wires). Then they are arranged at a circumferential interval of (5 - 10)d, as shown in Figure 2As shown in B and C, a ring-shaped filling structure is formed, and the inclination directions of B and C are opposite. The filling structures are staggered in each axial layer, with a total of 8 layers, forming the same height as the mesh structure. The mesh structure and the filling structure are arranged at intervals in the radial direction. For the liquid phase, after the liquid droplets pass through the mesh structure, due to the centrifugal force of the rotating bed, part of the liquid moves in a circular motion under the action of the centrifugal force and will collide again with the triangular unit structure of the filling structure in the circumferential direction, further dispersing the liquid in the circumferential direction and increasing the number of times of liquid dispersion in the circumferential direction and the residence time in the packing layer. For the gas phase, the filling structures are staggered in the axial direction, forming a spiral gas channel macroscopically, causing the gas to be shunted and mixed with the gas in the adjacent lower filling structure, having the effects of blocking and mixing. The inclination directions of the filling structure unit bodies in the middle packing and the lower packing are opposite, such as Figure 2 B and C in the figure, B is located in the middle packing, and C is located in the lower packing.

[0054] The axial flow blade structure, such as Figure 3 shown in A in the figure, the length, width and height of the cube occupied by the whole blade are all (20 - 50)d, evenly distributed in the circumferential direction, with a total of 12, forming an axial flow fan-like structure, such as Figure 3 shown in B in the figure. This axial flow blade structure is embedded in the mesh structure and the filling structure, in the 3rd to 7th circles counted from the inside to the outside in the radial direction, such as Figure 3 shown in C in the figure. In the 4 circles of filling structure occupied by the axial flow blade structure, the interval distance of the frame structure composed of triangular unit bodies is twice that in other circles, such as Figure 3 shown in C in the figure. Due to the characteristics of the axial flow blade, a low-pressure area is formed at the inner edge of the packing when the packing rotates, and the gas will be sucked in and then enter the packing along the axis, making the gas evenly distributed in the packing and increasing the coalescence times of the liquid droplets in the packing.

[0055] The inclination directions of the frame structures composed of triangular unit bodies in the filling structures of the lower packing and the middle packing are different. The filling structure of the lower packing is in the same rotation direction as the rotating bed, such as Figure 2 shown in B in the figure, and the filling structure of the middle packing is opposite to it, such as Figure 2As shown in C. Macroscopically, the gas spirally ascends along the channel. At the junction of the two packings, the gas flow direction suddenly changes, intensifying the gas turbulence and expanding the turbulent effect area in the packing. An axial flow blade structure is set in the lower packing. The gas enters from the gas inlet. Due to the characteristics of the axial flow blades, the gas is more likely to enter from the center of the packing when entering the packing, making the gas distribution more uniform, giving the gas axial kinetic energy, and increasing the gas-phase disturbance. The liquid enters the packing radially under the action of the distributor and is dispersed into tiny liquid films, liquid filaments, and liquid droplets due to the centrifugal force. Since the axial flow blade structure is similar to a baffle structure, it can increase the coalescence times of the liquid in the packing. In the 3 - 7 turns of the structure occupied by the axial flow blade structure, the spacing distance of the frame structure composed of triangular unit bodies in the filling structure is twice that of other filling structures (as shown in Figure 3 D). This makes it easier for the gas to enter from the inner edge of the packing, and the gas is more evenly distributed in the packing. The height of the lower packing is 30 mm, the height of the middle packing layer is 40 mm, the inner diameters are all 70 mm, and the outer diameters are all 195 mm.

[0056] The demisting structure is composed of an inclined baffle, a cylinder, and a tile structure plate. No liquid is sprayed in this layer. The gas passes through the first two packings axially, mixes in the gap between the upper packing and the middle packing, and then enters the upper packing. The inclined baffle changes the gas velocity and direction. Due to inertia, the water mist in the gas impacts the surface of the inclined baffle and is collected in the groove formed by the tile structure plate and the inclined baffle. Then, due to the centrifugal force, the liquid droplets are radially thrown outwards. During this process, the small liquid droplets slowly coalesce into larger liquid droplets, flow down after hitting the wall of the ring fixing plate, thereby reducing the phenomenon of liquid entrainment and ensuring the purity of the gas-phase product.

[0057] Description of the cylinder structure: Figure 4 It is a schematic diagram of the installation method of only one inclined baffle structure (the fan-shaped structure formed by points A, B, and C) in the upper packing in the cylinder. There are three cylinders, which are numbered 1, 2, and 3 from the inside to the outside radially. The inner and outer sides are thinner, and the middle layer is thicker (for fixing the upper packing), and the height is equal to the axial height of the upper packing. Figure 6 It is the dimension diagram (top view) of the cylinder. The dotted line in the figure is the thickness center line of the annular cylinder, and the solid line is the inner and outer edges of the cylinder structure. As shown in Figure 6 , the inner diameter of the first circle of the cylinder is D 1 , the outer diameter is D 2 , the thickness is a 1 , the thickness of the second circle of the cylinder is a 2 , the inner diameter of the thickness center line of the second circle of the cylinder is D 3 , that is, the inner diameter is D 3 - a 2 , the outer diameter is D 3 + a 2, the outer diameter of the third circle of cylinders is D 4 ; in this embodiment, D 1 is taken as 65 mm. The inner diameter of the first circle of cylinders is the inner diameter of the upper packing. The radial thickness of the first circle of cylinders is a 1 = 2 mm, and the outer diameter of the first circle of cylinders is D 2 = 2a 1 + D 1 . The radial thickness of the second circle of cylinders is a 2 = 12 mm, and the outer diameter D of the third circle of cylinders 4 = 200 mm, and the thickness is 2 mm (the same as a 1 ). The second inclined baffle is located between the second circle of cylinders and the third circle of cylinders; the first inclined baffle is located between the second circle of cylinders and the first circle of cylinders; the second circle of cylinders is located at the middle position of the two circles of inclined baffle structures.

[0058] After determining the cylinder dimensions, determine the dimensions of the inclined baffle structure and the installation method.

[0059] Description of the inclined baffle structure: The inclined baffle structure is a fan-shaped structure, with two straight sides and one arc side. For example Figure 4 the fan ABC in the figure, which is installed in the middle of the two circles of inclined baffle structures. Point C is inlaid in the inner cylinder and is tangent to the inner edge of the inner cylinder. The other arc AB is embedded in the outer cylinder. After this structure rotates upward by a certain angle with side AC as the base side, it is arrayed at a certain angular interval along the inner edge of the inner cylinder in the circumferential direction to form a circle of inclined baffle structures. The sizes of the inclined baffle structures are all the same, the height does not exceed the overall height of the upper packing, and it is ensured that the gap between the bottom of the inclined baffle and the middle packing is between 8 mm and 15 mm.

[0060] The specific construction method of the inclined baffle structure is as follows:

[0061] As Figure 6 shown, in the radial horizontal plane, draw a horizontal auxiliary line through the center of the circle O (i.e., the center point of the packing and also the center point of the cylinder) to intersect the outer edge of the inclined baffle at point A. Rotate AO counterclockwise with point A as the center of the circle by a certain angle and be tangent to the inner edge of the first circle of cylinders at point C. AC is one side of the inclined baffle. Let β be the included angle between side AO and AC. Connect OC. Then the calculation method of angle β is as follows:

[0062]

[0063] Figure 5 and Figure 6 the L shown in 1 is the width occupied by the inclined baffle in the top view state. Suppose the number of inclined baffles in one circle in the circumferential direction is m = 16 pieces. Then the calculation method of L 1 is as follows:

[0064]

[0065] Draw a perpendicular line to AC, intersecting the ring where D is located at point B, and make the length of the perpendicular line equal to L 3 Connect BC. The structure composed of the sector ABC is the horizontal plane projection of the inclined baffle 1 , that is, the structure composed of the sector ABC is the horizontal plane projection of the inclined baffle

[0066] As Figure 5 shown, it is a schematic structural diagram of the upper packing. The structure composed of ABC in the figure is the vertical plane projection of the inclined baffle. L 2 is the actual width of the inclined baffle. The angle formed with the plane after rotating a certain angle upward with the AC side as the base side is denoted as α = 45°, then L 2 The calculation method is as follows

[0067]

[0068] The thickness of the inclined baffle is b = 2mm. H 1 is the height of the upper packing (the same as the height of the cylinder), H 2 is the height of the packing of the inclined baffle, and H 1 > H 2 , the calculation method is as follows

[0069] H 2 = L 1 tanα + bcosα

[0070] The installation position of the bottom of the inclined baffle is the same as the height where the auxiliary line M is located in Figure 5 , that is, the installation height of points A and C in the vertical direction of the cylinder, which is 8.47mm different from the bottom of the upper packing (H 1 - H 2＝ 8.47mm). B' is the projection of point B on the radial plane where the auxiliary line M is located

[0071] Given the above parameters, the installation method and size of the inclined baffle have been determined. Next, construct the inclined baffle itself. As Figure 7 shown, it is the actual shape diagram of the inclined baffle (the plan view of the sector ABC). The dimension calculation method in the figure is as follows

[0072] 1. First, find the major semi-axes of this group of ellipses, which are in turn The minor semi-axes, which are in turn The three ellipses in the figure are ellipse 1, ellipse 2, and ellipse 3 respectively. Their major axes coincide with the y-axis, and their minor axes coincide with the x-axis. The original coordinate is point O

[0073] 2. The intersection of ellipse 1 and the y-axis is P, and the intersection of ellipse 2 and the y-axis is S. With point P as the center and L 2Draw a circle with a radius to intersect the y-axis at point E. Draw two parallel lines to the x-axis through point P and point E, which intersect the ellipse 3 at points A and B respectively.

[0074] 3. Connect BS and extend it to intersect the ellipse 1 at point C. Connect ABC, which is the true shape of the inclined baffle.

[0075] 4. Thicken the inclined baffle with a thickness of b. Using the AC point as the base side, rotate the inclined baffle upward by an angle of α = 45° with the radial plane.

[0076] Arrange the inclined baffle structure according to the Figure 5 、 6 shown position. Then, with point O as the center and D 1 as the diameter, rotate the inclined baffle circumferentially by m = 16, and the rotation angle is 360° / m to form the first circle of inclined baffles.

[0077] The drawing method of the second circle of inclined baffles is the same as that of the first circle of inclined baffles. During the construction process of the second circle of inclined baffle structure, the second and third circles of cylinders are regarded as the first and second circles of cylinders in the construction process of the inclined baffle structure respectively. And the number m of the second circle of inclined baffles is determined according to the actual situation. If there are more cylinder layers, it can be deduced by analogy.

[0078] Description of the tile structure plate: The tile structure is as shown in A of Figure 8 . The tile thickness is 2mm, the length does not exceed the size of the inclined baffle, and the height is 1 / 2 of the inclined baffle spacing, about 8mm. As shown in B of Figure 8 , one of its sides is inserted into the inclined baffle structure, and the formed groove direction is opposite to the air flow direction (the air flow direction is from bottom to top). The groove width is about 6mm, and the installation direction is the same as the packing diameter direction. The tile structure plates are arranged staggered above and below the inclined baffle, so that the tile structure plates between adjacent inclined baffles do not affect each other and are evenly arranged, as shown in C of Figure 8 .

[0079] As shown in D of Figure 8 is the final structure schematic diagram of the demisting layer.

[0080] The three kinds of packings are finally stacked axially to form a composite structured packing, as shown in Figure 9 , with an inner diameter of 65mm, an outer diameter of 200mm, and a height of 100mm.

[0081] As shown in Figure 10As shown in the figure, the above structured packing is applied to a cross-flow rotating packed bed device, which includes a fan 1, a cross-flow rotating packed bed 3, a motor 9, a recovered liquid storage tank 10, a raw material liquid storage tank 12, and a centrifugal pump 11. The bottom side of the cross-flow rotating packed bed is provided with a gas inlet 2, and the top is provided with a liquid inlet 4. The bottom of the liquid inlet pipe is provided with a liquid distributor 5, and the outlet of the liquid distributor 5 is arranged facing the packing rotor 6. One side of the top of the cross-flow rotating packed bed is provided with a gas outlet 7, and one side of the bottom is provided with a liquid outlet 8. The liquid outlet 8 is connected to the recovered liquid storage tank 10. The gas-liquid contact process is as follows: The gas phase enters from the gas inlet at the bottom of the packing and axially passes through the packing from bottom to top; the liquid phase enters from the liquid inlet and radially passes through the packing from inside to outside through the liquid distributor. The gas and liquid phases are in staggered contact, mixing and reacting inside the packing. After the reaction, the gas and liquid phases are discharged from the gas outlet and the liquid outlet respectively.

[0082] The operating mode of the described cross-flow rotating packed bed device is as follows:

[0083] (1) The gas enters from the gas inlet. The axial-flow blades in the lower layer of the packing have the functions of disturbing, entraining gas and coalescing liquid in the packing. Due to the characteristics of the axial-flow blades, they have a pressurizing effect on the gas during rotation, reducing the gas-phase pressure drop and avoiding the need for an additional fan; at the same time, the gas is more likely to enter from the inner edge of the packing, and the gas distribution is more uniform; the liquid is dispersed radially into the packing layer under the action of the distributor and is divided into tiny liquid films, liquid filaments and liquid droplets due to the centrifugal force, and then is aggregated by the packing and the blades.

[0084] (2) The reticular structure and the packing structure are the structures for dispersing and coalescing the gas and liquid phases in the packing, and they exist in the lower and middle layers of the packing. The gas entering from the gas inlet at the bottom of the packing first contacts the lower layer of the packing. The inclination direction of the packing structure is the same as the rotation direction of the cross-flow rotating packed bed, which is beneficial for the gas to enter the packing. In the packing structure inlaid with axial-flow blades, the spacing between the triangular unit bodies is twice that in other layers, making it easier for the gas to enter from the inner edge of the packing and evenly distributing the gas in the packing. The channels in the packing layer are inclined and staggered between layers, causing the gas to be shunted while mixing with the gas in the channels of the adjacent lower packing layer, having a blocking and mixing effect. Macroscopically, the gas spirally rises along the channels, and the gas flow direction suddenly changes at the junction of the two packings, increasing the gas turbulence degree. The liquid enters the packing radially under the action of the distributor and first enters the reticular structure. The structure with different wire diameter combinations increases the dispersion degree of the liquid in the radial direction. After the liquid droplets pass through the reticular structure, due to the centrifugal force of the rotating bed, some of the liquid moves in a circular motion under the centrifugal force and will collide again with the triangular unit bodies of the circumferential packing structure, further dispersing the liquid in the circumferential direction, increasing the number of times of liquid dispersion in the circumferential direction and the residence time of the liquid in the packing layer.

[0085] (3) The gas passes axially through the following two layers of packing, mixes in the gap and then enters the upper packing layer. The inclined baffle changes the gas velocity and direction, increasing the gas turbulence degree. The demisting structure layer does not spray liquid, reducing the liquid entrainment phenomenon. The gas carrying water mist passes axially from bottom to top. Due to inertia, it impacts the surface of the inclined baffle and then enters the baffle gap. The liquid droplets will gather inside the staggered tile-shaped structure and slowly coagulate into larger droplets during the process of being thrown out along the radial blade surface. After being thrown onto the concentric circle wall, they flow downward into the middle packing layer for secondary reaction, thus greatly reducing the entrainment of liquid droplets and liquid foams and ensuring the purity of the gas-phase product and the operation safety of the equipment.

[0086] The three packing layers are axially superposed, changing the gas-liquid flow direction multiple times, effectively realizing multiple changes in the axial velocity and direction of the gas, and increasing the turbulent effect area in the packing.

[0087] The above embodiments are only partial embodiments of the present invention and are not intended to limit the embodiments of the present invention. For other different forms of changes or variations in the relevant art, any obvious changes derived from the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. A composite structured packing for a high gravity cross-flow rotating bed, characterized in that: It includes three packing layers: upper, middle and lower. Three different regular packings are stacked axially to form different gas-liquid phase channels. The upper packing is a demisting structure. The lower and middle packings are composed of a filling structure and a mesh structure. The filling structures in the lower and middle packings are inclined in opposite directions. A circle of axial flow blades is inlaid at the inner edge of the lower packing. The filling structure is a frame structure composed of triangular units, which are stacked up and down at an angle of 30° to 60°, evenly distributed in the circumferential direction and staggered in the axial direction; The mesh structure comprises transverse wires and longitudinal wires. The cross-section shape of the transverse wires is circular wires, and the cross-section shape of the longitudinal wires is teardrop-shaped wires. The mesh structure and the filling structure are arranged at intervals in the radial direction.

2. The composite structured packing for the high gravity cross-flow rotating bed according to claim 1, characterized in that: The length, width and height of the rectangular block occupied by the axial flow blades are 10 to 30 mm respectively, and 9 to 27 are evenly distributed in the circumferential direction; the axial flow blade structure is embedded in the lower layer of filler at the inner edge of the filler, and the spacing between the triangular units in the filling structure with the axial flow blades added is twice that in other layers.

3. The composite structured packing for the high gravity cross-flow rotating bed according to claim 1, characterized in that: The upper filler is a demisting structure that does not spray liquid, and is composed of an inclined baffle, a cylinder, and a tile structure plate; the cylinder is provided with 3 to 20 circles, which are arranged in a concentric circle manner, in order to collect condensate; the inclined baffle is a fan-shaped structure, with two straight sides and one arc side; the inclined baffles are installed in the same radial direction, the intersection of the two straight sides is connected to the inner cylinder, and the arc side is connected to the outer cylinder, and are evenly distributed at intervals of 12° to 36° in the circumferential direction, and the angle between the inclined baffle and the horizontal plane is 40° to 60°, and the circumferential inclination direction is the same as the rotation direction of the rotor; Tile structure plates are staggeredly installed on the upper and lower sides of the inclined baffles, so that the baffle structures between adjacent inclined baffles do not affect each other and are evenly arranged.

4. The composite structured packing for the high gravity cross-flow rotating bed according to claim 3, characterized in that: The thickness of the tile structure plate is 1~3mm and the length is less than the length of the inclined baffle. The tile height is 1 / 2 of the inclined baffle spacing. One of its edges is inserted into the inclined baffle structure. The direction of the groove formed by the tile is opposite to the airflow direction, and the installation direction is the same as the radial direction of the filler.

5. The composite structured packing for the high gravity cross-flow rotating bed according to claim 1, characterized in that: The filling structure is installed in the middle and lower layers of fillers, and the frame structure composed of triangular units is evenly distributed in the circumferential direction and staggered in the axial direction. The filling structures in the lower and middle layers of fillers are tilted in opposite directions, which increases the probability of droplet dispersion and aggregation while constructing a gas phase spiral channel, increases gas turbulence, and improves the turbulence effect area in the filler; the frame structure composed of triangular units is composed of two "×"-shaped structures stacked up and down, with an angle of 30° to 60° with the horizontal direction, and its six vertices are embedded in the horizontal wires of the mesh structure for fixation, and are evenly arranged at intervals of 4mm to 10mm in the circumferential direction, and then each layer is staggered in the axial direction to form the same height as the mesh structure.

6. The composite structured packing for the high gravity cross-flow rotating bed according to claim 1, characterized in that: The horizontal and vertical wires of the mesh structure increase the cutting effect on the droplets and increase the specific surface area of ​​the filler; the teardrop-shaped wire diameter is composed of an isosceles triangle and an arc, wherein two equal sides of the triangle are tangent to the arc; the length and width of the teardrop-shaped wire differ from the diameter of the circular wire by no more than 5 mm and are not less than 1 / 2 of the diameter of the circular wire.

7. A method for constructing a composite structured packing for a high gravity cross-flow rotating bed according to any one of claims 1 to 6, characterized in that: Firstly, the regular packing model is designed using 3ds Max software. The freedom of software design is used to design the mesh structure, filling structure, axial flow blade structure and demisting structure required for the three-dimensional packing model. The lower and middle packings are constructed based on the mesh structure and filling structure, and the axial flow blade structure is set in the lower packing. Finally, the upper packing structure is constructed. The three types of packings are stacked axially to form a complete packing structure, and the solid packing is printed out using 3D printing technology.

8. A cross-flow rotating packed bed device made of the composite structured packing for supergravity cross-flow rotating bed according to any one of claims 1 to 6.

9. The cross-flow rotating packed bed device according to claim 8, characterized in that: The cross-flow rotating packed bed device comprises a fan, a cross-flow rotating packed bed, a motor, a recovery liquid storage tank, a raw liquid storage tank, and a centrifugal pump; wherein a gas inlet is provided at the bottom side of the cross-flow rotating packed bed, a liquid inlet is provided at the top, a liquid distributor is provided at the bottom of the liquid inlet pipe, the outlet of the liquid distributor faces the packing rotor, the bottom of the packing rotor is connected to the motor, a gas outlet is provided at one side of the top of the cross-flow rotating packed bed, a liquid outlet is provided at one side of the bottom, and the liquid outlet is connected to the recovery liquid storage tank; The gas-liquid contact process is as follows: the gas phase enters from the gas inlet at the bottom of the packing and passes through the packing axially from bottom to top; the liquid phase enters from the liquid inlet and passes through the packing radially from the inside to the outside through the liquid distributor. The gas and liquid phases contact, mix and react alternately in the packing; after the reaction is completed, the gas and liquid phases are discharged from the gas outlet and liquid outlet respectively.

10. The cross-flow rotating packed bed device according to claim 8, characterized in that: The operation mode is: (1) The gas enters the packing from bottom to top. The axial flow blades in the lower packing have a pressurizing effect on the gas when rotating, reducing the gas phase pressure drop and avoiding the need for an additional fan. At the same time, the gas is easier to enter from the inner edge of the packing, and the gas distribution is more uniform. (2) The gas spirals up along the filling structure, and the staggered arrangement of the filling structure layers causes the gas to disperse and coalesce multiple times; the liquid collides with the mesh structure, and the combination of different wire diameters enhances the radial dispersion of the liquid; the centrifugal force causes part of the liquid to collide with the filling structure unit body, achieving multiple rapid dispersion-coagulation-dispersion of the liquid, increasing the gas-liquid contact area and time; (3) The demisting structure does not spray liquid. When the gas passes through this layer of packing along the axial direction, the water mist in the inertial gas hits the baffle surface and gathers and aggregates in the tiles; then due to the action of centrifugal force, the droplets are thrown outward radially, and gradually grow and gather on the cylinder wall, flowing into the middle packing layer for secondary reaction, reducing liquid foam entrainment and ensuring gas phase purity and equipment safety; The three packing layers are axially superimposed, changing the gas-liquid flow direction multiple times, effectively realizing multiple changes in the gas axial velocity and direction, and increasing the turbulence effect area in the packing.

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