A gas-liquid mixing device

Abstract

The application provides a gas-liquid mixing device, which comprises a shell, a filter core assembly in the shell, a top cover sealingly connected to one end of the shell, a center rod with a hole structure and a diffusion layer in a folded shape around the outer periphery of the center rod, a first inlet for a first fluid to fill the center rod, a second inlet for a second fluid to fill the space between the diffusion layer and the shell, the first fluid and the second fluid being in different phases, the folded diffusion layer forming a plurality of folds, the valleys of the folds being close to the center rod, and the diffusion zones for fluid diffusion being provided between the valleys of adjacent two folds, wherein the diffusion coefficient K of the diffusion zone is K=H*C / M, M is the number of the diffusion zones, C is the outer periphery circumference of the center rod, and H is the average value of the fold height; the range of K is 5-35, the range of H is 5-30 mm, and the diffusion coefficient K is 5-35. The device has high gas-liquid mixing efficiency, and the prepared solution has more uniform concentration.

Description

Technical Field

[0001] This invention relates to the field of gas-liquid mixing, and in particular to a gas-liquid mixing device. Background Technology

[0002] In the process of solution preparation, if the gas-liquid mixture is not uniform enough, the local solution concentration may be too high and reach saturation. In this case, the gas is not easy to dissolve in the liquid and exists in the solution in the form of bubbles. Therefore, the prepared solution concentration is uneven, which affects the solution preparation.

[0003] Chinese patent application CN1642628A discloses a hollow fiber membrane contact device and method. The device, a liquid-gas phase contactor for contacting a liquid with a gas, comprises: a) a bundle of numerous perfluorothermoplastic hollow fiber membranes having a first end and a second end; the membrane is a porous membrane having an outer surface and an inner surface, the inner surface including an inner cavity; b) each end of the fiber bundle is encapsulated with a liquid-impermeable perfluorothermoplastic sealing material, forming a single-end structure surrounded by a perfluorothermoplastic shell, wherein the fiber ends are open to fluid; c) the shell has an inner wall and an outer wall, wherein the inner wall defines a fluid volume between the inner wall and the hollow fiber membrane cavity; d) the shell has an inlet for supplying gas to the first end of the fiber bundle to contact the liquid and a first gas outlet connection for removing gas from the second end; e) the shell has a liquid inlet connection for supplying liquid to contact the gas passing through the hollow fiber membrane and a liquid outlet connection for removing the liquid from contact with the gas from the shell.

[0004] This patent uses hollow fiber membrane bundles for gas-liquid mixing. As can be seen from the specification, the liquid flows inside the hollow fiber membrane, and the gas is introduced between the hollow fiber membrane bundle and the shell. The porous structure of the hollow fiber membrane allows the gas to pass through the hollow fiber membrane and mix with the liquid in the inner cavity. This patent uses multiple hollow fiber membranes assembled into a membrane bundle. The high density of the hollow fiber membranes in the bundle results in a larger gas permeation area per unit volume, thereby increasing gas-liquid mixing efficiency. However, this also introduces another problem: gas diffusion to the hollow fiber membrane cavity at the center of the bundle requires passing through multiple hollow fiber membranes from the outside of the bundle towards the center, increasing the resistance to gas diffusion towards the center. This leads to a smaller amount of gas diffusion at the center of the bundle per unit time, resulting in an excessively low solution concentration at the center. Consequently, the solution concentration within the hollow fiber membranes from the outer layer to the center of the bundle is inconsistent, leading to uneven concentration of the prepared solution. In other words, although the gas-liquid mixing efficiency is increased, the uniformity of the prepared solution is poor. To improve the uniformity of the prepared solution, the density of the hollow fibers in the bundle needs to be reduced, making it easier for gas to enter the hollow fiber membrane cavity at the center of the bundle. However, this would reduce the gas diffusion area per unit volume, thereby reducing the gas-liquid mixing efficiency.

[0005] Application publication number CN100361729C discloses a pleated structure for forming a gas transfer membrane, and also discloses a contactor device for transferring gas from a first fluid to a second fluid through the membrane. The device includes: a cylindrical pleated membrane filter element located within a housing, the housing having a first inlet and a first outlet for the first fluid and at least one second outlet for the second fluid, and a baffle located in a first flow channel of the first fluid. The baffle's function is to introduce fluid into the gaps between the pleated filter element's sections.

[0006] This patent uses baffles to control the flow direction of the first fluid, thereby guiding the first fluid into the gaps between the pleated filter elements. Inevitably, the first fluid collides with the baffles during its flow, causing it to rush towards the filter element. To improve gas-liquid mixing efficiency, the flow rate of the first fluid needs to be increased. However, with a higher flow rate, the first fluid, guided by the baffles, experiences a greater impact force upon impact with the baffles, impacting the pleated structure on the filter element. This can easily lead to excessive deformation or even collapse of localized pleated structures under such impact, resulting in a decrease in both solution uniformity and gas-liquid mixing efficiency.

[0007] In summary, designing a gas-liquid mixing device that achieves high gas-liquid mixing efficiency while producing a more uniform solution concentration is a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a gas-liquid mixing device that solves the problems of low gas-liquid mixing efficiency and uneven concentration of the prepared solution.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A gas-liquid mixing device includes a housing and a filter element assembly located within the housing. One end of the housing is sealed with a top cover. The filter element assembly includes a central rod with a porous structure and a folded diffusion layer surrounding the central rod. The top cover has a first inlet communicating with the central rod and a second inlet communicating with the housing. The first inlet is supplied with a first fluid to fill the central rod, and the second inlet is supplied with a second fluid to fill the space between the diffusion layer and the housing. The other end of the housing has an outlet. The first fluid and the second fluid are in different phases. The folded diffusion layer forms several folds, with the fold valleys close to the central rod. Between two adjacent fold valleys, there is a diffusion zone for fluid diffusion. The diffusion coefficient of the diffusion zone is K=H*C / M, where M is the number of diffusion zones, C is the outer circumference of the central rod, and H is the average fold height. K ranges from 5 to 35 mm, and H ranges from 5 to 30 mm.

[0010] In the gas-liquid mixing device of the present invention, the first fluid and the second fluid are in different phases; the first fluid is a gas and the second fluid is a liquid; or, the first fluid is a liquid and the second fluid is a gas. The first fluid fills the central rod, and the second fluid flows between the diffusion layer and the outer shell. The first fluid diffuses through the central rod and through the folded diffusion layer to the second fluid. The folded diffusion layer increases the diffusion area of ​​the first fluid, while making the first fluid diffuse evenly to the second fluid and able to mix with the second fluid in a timely manner. The folded diffusion layer of the present invention forms several folds, and there is a diffusion area for the diffusion of the first fluid between two adjacent folds. The first fluid fills the diffusion area and diffuses to the second fluid through the diffusion layer. The first fluid diffuses from the inside to the outside of the diffusion layer, and the second fluid flows between the folds on the outside of the diffusion layer, increasing the contact time and contact area with the first fluid. The outside of the diffusion layer is the side that contacts the second fluid.

[0011] A diffusion zone is formed between two adjacent folds of the folded diffusion layer. The cross-sectional shape of the diffusion zone is approximately an isosceles triangle. The diffusion coefficient K of the diffusion zone is formulated as: K = H * C / M. The fold height H is the length between the fold peak and fold valley of the diffusion layer, i.e., H is the length of the leg of the isosceles triangle, and C / M is the length of the base of the isosceles triangle. Therefore, the range of values ​​for the diffusion coefficient K and the fold height H limits the shape of the triangle, i.e., determines the shape of the diffusion zone. When the fluid flow causes a certain impact on the folds, the shape of the diffusion zone in this application gives the folds a certain ability to deform and recover deformation. The folds diffuse in the first fluid diffusion and in the second... Under the impact of the fluid, several folds undergo a certain degree of bending deformation. As the second fluid flows outside the diffusion layer, the bent deformation positions relax. With the continuous bending and relaxing between folds, the second fluid continuously replenishes the positions where the folds have bent deformation, thus achieving the purpose of flow guidance. This allows the gas diffused to the outside of the filter element to be instantly carried away by the second fluid, increasing the diffusion amount of the first fluid. Simultaneously, the flow guidance fills the spaces between adjacent folds, preventing folds from collapsing, reducing the gas diffusion area, and consequently reducing the amount of local gas diffusion, thus reducing the homogeneity of the prepared solution. Furthermore, the shape of the diffusion zone in this application provides a certain degree of support to the folds. When the folds are impacted by the fluid, it effectively prevents fold collapse, reducing the gas diffusion area and significantly decreasing the amount of gas diffusion at the collapsed positions. This ensures the uniformity of gas diffusion, guaranteeing the uniformity of the prepared solution concentration. At the same time, the diffusion zone has a large diffusion area, allowing the first fluid to diffuse at a large rate.

[0012] In summary, the shape of the diffusion zone formed in this application provides a large diffusion area for the gas and the filter element. The continuous deformation and recovery of the pleats achieves a guiding effect, while also providing a certain degree of support, ensuring the uniformity of gas diffusion and thus guaranteeing the uniformity of the prepared solution concentration. Therefore, this device has both high gas-liquid mixing efficiency and ensures the uniformity of the prepared solution concentration.

[0013] Furthermore, if the base of the triangle in the diffusion zone cross-section is too long and the length of its legs is too short, the triangle becomes short and stout, reducing the gas diffusion area and consequently the amount of gas diffused, thus lowering the gas-liquid mixing efficiency. Simultaneously, the short and stout shape reduces the deformation and recovery ability of the folds, decreasing their flow-guiding capacity and further reducing the gas-liquid mixing efficiency and the uniformity of the prepared solution. Conversely, if the base of the triangle in the diffusion zone cross-section is too short and the length of its legs is too long, the triangle becomes long and slender, reducing its support for the folds and making them prone to collapse. This reduces the diffusion area of ​​the first fluid, thus lowering the amount of first fluid diffused. It also increases the resistance to fluid flow between adjacent folds, further reducing the gas-liquid mixing efficiency. Therefore, when the fold height H is relatively large, the diffusion zone coefficient K cannot be too small. That is, when the fold height H of this application is 30 mm, the diffusion zone coefficient K is not greater than 35. When H is relatively large or small, the diffusion zone coefficient K cannot be too large. That is, when the fold height H of this application is 5 mm, the diffusion zone coefficient K is not less than 5 in order to meet the actual needs of this application. Therefore, the range of diffusion zone K is 5-35, and the range of fold height H is 5-30 mm. The two complement each other and work together to ensure that the shape of the diffusion zone meets the actual needs.

[0014] Furthermore, the diffusion coefficient K of the diffusion region is 7-30; the diffusion layer includes a membrane, which is a waterproof and breathable PTFE membrane, and the air permeability of the PTFE membrane is 1-10 s / ml / inch. 2 .

[0015] In this application, the first fluid is a gas, the second fluid is a liquid, and PTFE is a hydrophobic material with excellent waterproof and breathable properties. Therefore, the PTFE membrane has good waterproof performance and high mechanical strength, preventing it from rupturing under liquid impact. The air permeability of the PTFE membrane in this application is 1-10 s / ml / inch. 2If the permeability of the PTFE membrane is too high, the gas diffusion rate per unit time and unit membrane area will be too large, causing the gas in the solution near the diffusion layer to reach saturation instantaneously. Subsequently, the diffused gas will move upwards in the form of bubbles, making it difficult for the gas to diffuse towards the inner wall of the outer shell, resulting in uneven solution concentration in the radial cross section of the outer shell. If the permeability of the PTFE membrane is too low, the diffusion rate per unit time and unit membrane area will be too low, resulting in too low concentration of the prepared solution, thereby reducing the gas-liquid mixing efficiency. At the same time, when the pleats are impacted by liquid, they are prone to folding or the gap between adjacent pleats will be too small, increasing the gas diffusion resistance and thus reducing the gas diffusion rate. By using an appropriate permeability of the PTFE membrane, the gas can have a suitable flow rate, "blowing open" the two adjacent pleats to avoid folding or the gap between adjacent pleats being too small. Therefore, if the permeability of the PTFE membrane is low, the amount of gas passing through per unit time will not be sufficient to "blow open" the two adjacent pleats. Furthermore, when the gas permeability of the PTFE membrane is relatively high, the diffusion coefficient of the diffusion zone should be relatively low to avoid both being too high simultaneously, which would lead to excessive gas diffusion per unit time in the filter element, resulting in uneven concentration of the prepared solution. Conversely, the diffusion coefficient of the diffusion zone should not be too low to avoid insufficient gas diffusion per unit time, failing to "blow open" adjacent folds, or resulting in excessively low concentration of the prepared solution. Therefore, when the gas permeability of the PTFE membrane is 10s / ml / inch... 2 When the permeability of the PTFE membrane is relatively low, the diffusion coefficient K of the diffusion zone should be relatively increased to meet the gas diffusion requirements per unit time. However, the diffusion coefficient of the diffusion zone should not be too large, as this can easily lead to excessive gas flow per unit time, for reasons already stated above and not repeated here. Therefore, when the permeability of the PTFE membrane is 1s / ml / inch... 2 At that time, the diffusion coefficient K in the diffusion region should not be greater than 30.

[0016] Preferably, the areal density of the membrane is 10-25 g / m³. 2 The thickness of the membrane is 20-150 μm.

[0017] The areal density of the membrane is related to the diffusion resistance of the gas, which in turn is related to the efficiency of the gas passing through the membrane and contacting the liquid. Therefore, this invention controls the areal density of the membrane to correspond to the diffusion coefficient K of the diffusion zone, so that the gas velocity passing through the membrane is matched with the flow velocity of the liquid in the diffusion layer. The appropriate amount of gas and liquid allows the gas and liquid to mix in time when they come into contact, avoiding excessive gas entering the liquid and not being able to mix in time, resulting in large bubbles, which in turn cause eddies between adjacent folds, affecting the gas diffusion rate and the uniformity of gas-liquid mixing. It also avoids the amount of gas entering the liquid being too small, resulting in a low solution concentration. On the other hand, the areal density and thickness of the membrane reflect the supporting strength of the membrane itself and affect the bending strength of the membrane. The membrane of this application uses the supporting force between adjacent folds to achieve the deformation and recovery of the folds, and in combination with the supporting strength of the membrane itself, the membrane undergoes a certain deformation as the second fluid flows, causing the folds to undergo a certain degree of bending deformation. Under the impact of the liquid, the folds continuously undergo bending deformation and recovery, prompting the liquid to flow to the adjacent folds of the diffusion layer, fully contacting and mixing with the gas, so as to increase the gas-liquid mixing efficiency.

[0018] Preferably, the diffusion layer further includes a first support mesh and a second support mesh, the first support mesh being located on the side of the membrane body closer to the central rod, and the second support mesh being located on the other side of the membrane body, wherein the thickness of the first support mesh is greater than the thickness of the second support mesh.

[0019] The functions of both the first and second support nets are to support the membrane, enabling it to form folds and effectively preventing adjacent membranes from collapsing and blocking the flow channels in the diffusion zone, thus maintaining a stable diffusion coefficient. The second support net is made of the same material as the first. In the specific scenario where the first fluid is gas and the second fluid is liquid, the first support net is relatively thicker, increasing its support strength. When the second support net and the membrane approach the central rod under the impact of the liquid, the first support net has sufficient strength to resist deformation, preventing the diffusion layer from blocking the holes on the central rod. It also prevents folding or collapse of the diffusion layer, ensuring the stability of the diffusion zone and guaranteeing a suitable effective diffusion area for the gas, thus ensuring the uniformity of the prepared solution. The relatively thin second support net allows for some deformation when impacted by the liquid, causing the folds to bend to a certain extent. Under the impact of the liquid at different positions and angles, the folds continuously bend and expand, allowing the liquid to flow into the diffusion layer, fully contacting and mixing with the gas, ensuring high gas-liquid mixing efficiency.

[0020] Preferably, the ratio of the thickness of the first support mesh to the thickness of the second support mesh is 1.2-3.6; and the ratio of the areal density of the first support mesh to the areal density of the second support mesh is 1.4-4.4.

[0021] Since the membrane is located between the second and first support nets, controlling the thickness ratio and areal density ratio of the second and first support nets ensures that both the first and second support nets have appropriate support strength. Simultaneously, the first support net has relatively high stiffness, meaning it provides good support for both the membrane and the second support net. This effectively prevents significant deformation of the membrane and the second support net due to their thickness and areal density when liquid impacts the diffusion layer. The first support net's sufficient support strength effectively prevents deformation of the diffusion layer from blocking the holes in the central rod, and also prevents the diffusion layer from collapsing or folding between adjacent folds, reducing the diffusion coefficient of the diffusion zone and thus decreasing the gas diffusion rate.

[0022] Preferably, the thickness of the first support mesh is 65-95 μm, and the areal density of the first support mesh is 90-130 g / m³. 2 .

[0023] The first support mesh is located between the membrane and the central rod, on the side of the diffusion layer closer to the central rod. Therefore, the first support mesh has a high areal density and a large thickness, resulting in greater stiffness. When the diffusion layer deforms due to liquid impact, the first support mesh provides sufficient support for the second support mesh and the membrane, preventing excessive deformation of the diffusion layer and clogging of the holes on the central rod. At the same time, the first support mesh can also deform appropriately to buffer the deformation of the membrane, preventing the membrane from rupturing when subjected to large impact forces.

[0024] Preferably, the thickness of the second support mesh is 30-75 μm, and the areal density of the second support mesh is 50-90 g / m². 2 .

[0025] The second support mesh is located on the outside of the membrane and is subjected to liquid impact. The stiffness of the second support mesh is related to its thickness and areal density. The relatively small thickness and areal density of the second support mesh result in relatively small stiffness, giving it suitable support strength. On the one hand, it can buffer the impact force generated by a large amount of liquid. On the other hand, it can also meet the appropriate deformation requirements of the folds and the diffusion coefficient requirements of the diffusion zone. That is, while supporting the folds, the second support mesh can also deform to a certain extent with the direction of liquid flow, which can guide the liquid and allow the gas and liquid to come into contact and mix in time. This can prevent the gas from being unable to dissolve in time during the diffusion process into the liquid and remaining in the form of bubbles between adjacent folds of the membrane, blocking the gas diffusion path and thus reducing the gas diffusion efficiency.

[0026] Preferably, the length L1 of the second support net between the fold valley and the fold peak, the length L2 of the membrane body, and the length L3 of the first support net satisfy the following formula: L1 > L2, and the value of L1-L2 is 10-25mm; L3 > L2, and the value of L3-L2 is 5-15mm.

[0027] The length L3 of the first support net refers to the radial length between the peaks and valleys of the first support net; the length L2 of the membrane body refers to the radial length between the peaks and valleys of the membrane body. The first support net is located on the side of the membrane body closer to the central rod, and L3 > L2, so that there is a certain radial distance between the first support net and the membrane body. The purpose of the appropriate first radial distance between the first support net and the membrane body is that when the second support net and the membrane body are impacted by liquid, they deform towards the first support net. The first support net deforms under the impact force, and the first radial distance provides a buffer space for the membrane body to deform, so that the deformation of the second support net and the membrane body towards the first support net drives the second fluid to flow between adjacent folds, while avoiding large deformation of the fluid that damages the membrane body. That is, the first support net can also buffer the membrane body. In addition to its supporting function, when gas collides with the first support net, the first radial distance buffers the gas, preventing eddies from forming due to changes in flow velocity and direction after the collision, thus increasing the resistance of the gas through the waterproof and breathable membrane and reducing the amount of gas diffusion. If the first radial distance is large, the first support net is insufficient in restricting the deformation of the membrane and cannot provide timely support. When the waterproof and breathable membrane is subjected to a large impact and undergoes large deformation, it is prone to rupture. If the first radial distance is small, the first support net provides excessive support to the membrane, reducing the degree of deformation of the membrane with the liquid and thus reducing the overall deformation of the diffusion layer. This results in a poor flow guidance effect and fails to buffer the gas flow. The gas is prone to generating eddies within the folds of the membrane, further reducing the amount of gas diffusion.

[0028] The length L1 of the second support mesh refers to the radial length between the peaks and valleys of the second support mesh. The second support mesh is located outside the membrane, and L1 > L2, ensuring a certain radial distance between the second support mesh and the membrane. This appropriate second radial distance allows the second support mesh to extend and deform along with the liquid flow direction. It can guide fluid between adjacent folds, increasing the mixing volume of liquid and gas and promptly carrying away gas diffusing from the diffusion zone, thus increasing the gas diffusion rate. If the second radial distance is too large, the deformation of the second support mesh as it extends with the liquid will be small, rendering it unable to effectively guide the flow and carry away gas diffusing from the diffusion zone, thereby reducing the gas diffusion rate. If the second radial distance is too small, the deformation of the second support mesh as it extends with the liquid will easily lead to accumulation at the folds of the membrane, thus blocking the gas diffusion channels.

[0029] Preferably, the mesh count of the second support net is 28-100 meshes, and the mesh count ratio of the second support net to the first support net is 1.1-2.5.

[0030] As is well known, the larger the mesh count of the second support mesh (or the first support mesh), the smaller its pore size and the denser its pore structure. Therefore, controlling the mesh count of the second support mesh can effectively prevent the pores from being too small or too large. If the pores of the second support mesh are too small, the second support mesh increases the gas diffusion resistance and reduces the permeability of the diffusion layer. If the pores of the second support mesh are too large, the amount of gas diffusing into the liquid per unit time and per unit area is large. Since the instantaneous dissolution capacity of gas is limited, the gas that cannot dissolve in the liquid in time is prone to generating bubbles, leading to uneven gas-liquid mixing. Therefore, a suitable mesh count for the second support mesh ensures that the pore size is appropriate, allowing the gas to diffuse into the liquid in a more dispersed form, avoiding gas... The accumulation of a large amount of gas causes local saturation of the gas in the liquid, generating a large number of bubbles. This makes the gas and liquid mix more evenly and allows the gas to disperse quickly into the liquid, increasing the diffusion rate. The mesh size of the second support mesh is larger than that of the first support mesh, with a ratio between 1.1 and 2.5. This results in larger void sizes in the first support mesh, reducing the resistance to gas flow and facilitating diffusion. At the same time, it prevents collisions between the gas and the first support mesh, which alters the gas flow direction and velocity, causing eddies near the membrane and further reducing the amount of gas diffusion.

[0031] The mesh size of the second and first support meshes also needs to be set in consideration of the diffusion coefficient of the diffusion zone to make them compatible. This ensures that the gas velocity through the membrane matches the liquid velocity in the diffusion layer. Appropriate amounts of gas and liquid allow the gas and liquid to mix in time when they come into contact, avoiding excessive gas entering the liquid and not being able to mix in time, which would generate large bubbles and reduce the uniformity of the solution concentration.

[0032] Preferably, the end of the outer shell that is sealed and fixedly connected to the top cover is the first end, and the end with the outlet is the second end. The inner diameter D of the outer shell decreases gradually from the first end to the second end.

[0033] The filter element is located inside the outer casing. The filter element is cylindrical, with one end close to the first end of the outer casing and the other end close to the second end. Since the inner diameter of the outer casing decreases gradually from the first end to the second end, the distance between the filter element and the inner wall of the outer casing also decreases gradually from the first end to the second end. As a result, the hydraulic pressure between the filter element and the inner wall of the outer casing gradually increases from the first end to the second end. During the gas-liquid mixing process, as the liquid moves towards the outlet, the gradually increasing hydraulic pressure can prevent some small bubbles that have not dissolved in time from moving upward and accumulating to form large bubbles. The upward movement of large bubbles can cause uneven pressure inside the device. At the same time, it can also prevent the gas from evaporating from the liquid as the solution concentration increases during the gas-liquid mixing process and the liquid moves towards the outlet.

[0034] Preferably, the formula for the gradient change ΔD of the inner diameter of the outer shell is: ΔD = (D1-D2) / N, where D1 is the inner diameter of the first end, D2 is the inner diameter of the second end, and N is the length of the outer shell; the range of ΔD is 0.01-0.06.

[0035] The purpose of controlling the gradient variation range of the inner diameter of the outer shell is twofold: firstly, to control the hydraulic pressure difference between the two ends of the inner wall of the outer shell and the filter element, so that the hydraulic pressure at the second end is not too small, so as to prevent small bubbles from diffusing upward and accumulating into large bubbles, and at the same time to prevent the hydraulic pressure at the second end from being too large, which would cause the liquid to flow poorly and affect the diffusion rate of gas and liquid; secondly, it is also necessary to control the inner diameter of the second end to prevent the inner diameter of the second end from being too small, which would cause the liquid to stagnate at the outlet and create eddies.

[0036] In summary, compared with the prior art, the present invention has at least the following beneficial effects: By limiting the diffusion coefficient K and pleat height H of the diffusion zone, the present application enables the gas to have a larger diffusion area, enables the filter element to have a larger diffusion area, and enables the pleats to achieve the function of guiding flow during the continuous deformation and recovery process. At the same time, the pleats have a certain support capacity, ensuring the uniformity of gas diffusion, thereby ensuring the uniformity of the concentration of the prepared solution. Therefore, the device has both high gas-liquid mixing efficiency and ensures the uniformity of the concentration of the prepared solution. Attached Figure Description

[0037] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the external structure of the gas-liquid mixing device according to an embodiment of the present invention.

[0039] Figure 2 This is a schematic internal cross-sectional view of the gas-liquid mixing device according to an embodiment of the present invention.

[0040] Figure 3 This is a schematic diagram of the filter element assembly according to an embodiment of the present invention.

[0041] Figure 4 This is a cross-sectional schematic diagram of the filter element assembly according to an embodiment of the present invention.

[0042] Figure 5 for Figure 4 Enlarged view of point A in the image.

[0043] Explanation of reference numerals in the attached figures 1. Outer shell; 11. Top cover; 12. First inlet; 13. Second inlet; 14. Outlet; 15. First end; 16. Second end; 2. Filter element assembly; 21. Central rod; 22. Diffusion layer; 221. Pleats; 222. Diffusion zone; 223. Membrane body; 224. First support net; 225. Second support net. Detailed Implementation

[0044] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] As attached Figures 1 to 5 This invention provides a gas-liquid mixing device, including a housing 1 and a filter element assembly 2 located inside the housing 1. A top cover 11 is sealed to one end of the housing 1. The filter element assembly 2 includes a central rod 21 with a porous structure and a folded diffusion layer 22 surrounding the central rod 21. The top cover 11 has a first inlet 12 communicating with the central rod 21 and a second inlet 13 communicating with the housing 1. The first inlet 12 is supplied with a first fluid to fill the central rod 21, and the second inlet 13 is supplied with a second fluid to fill the space between the filter element assembly 2 and the housing 1. The first fluid and the second fluid are... Different phases, i.e., the first fluid is gaseous and the second fluid is liquid, or the first fluid is liquid and the second fluid is gaseous. In this embodiment, the first fluid is ammonia and the second fluid is deionized water. The pressure inside the filter element assembly 2 is greater than the pressure between the filter element assembly 2 and the outer shell 1, causing the first fluid to pass through the hole of the central rod 21, through the diffusion layer 22 and flow between the outer shell 1 and the filter element assembly 2, and come into contact with and mix with the second fluid that fills the outer periphery of the diffusion layer 22. The other end of the outer shell 1 is provided with an outlet 14, and the mixed solution is ammonia water, which is discharged from the outlet 14.

[0048] In this embodiment, the folded diffusion layer 22 forms several folds 221, each fold having a peak and a valley. The valleys are close to the central rod, and a diffusion region 222 for the diffusion of the first fluid is located between adjacent valleys. The distance from the valley to the fold height of the diffusion layer 22 is the fold height. The diffusion layer 22 is folded to form several diffusion regions 222. The first fluid fills the diffusion regions 222, and the second fluid fills the outer side of the diffusion layer 22. The outer side of the diffusion layer 22 is the side that contacts the second fluid. The first fluid passes through the diffusion region 222, contacts the second fluid, and mixes to form a solution. The fold height H, the number of diffusion regions M, and the outer perimeter length C of the central rod have a significant impact on the shape of the diffusion regions, and thus affect the diffusion coefficient K of the diffusion regions.

[0049] In this embodiment of the invention, the diffusion coefficient K of the diffusion zone 222 is K=H*C / M, where M is the number of diffusion zones 222, C is the outer perimeter of the central rod 21, and H is the average value of the fold height of the diffusion layer, which is the length between the fold peak and the fold valley of the diffusion layer. Based on practical experience, the fold height H ranges from 5 to 30 mm, and the diffusion coefficient K is 5 to 35. This allows the gas to have a large diffusion area, and the filter element to have a large diffusion area. During the process of the folds constantly deforming and recovering their deformation, the flow is guided, and at the same time, the folds have a certain supporting capacity, ensuring the uniformity of gas diffusion and thus ensuring the uniformity of the concentration of the prepared solution. Therefore, the device has both high gas-liquid mixing efficiency and ensures the uniformity of the concentration of the prepared solution.

[0050] To ensure a wider and more uniform distribution of the first fluid after passing through the diffusion layer 22, the diffusion layer 22 in this embodiment includes a membrane 223. The membrane 223 is a waterproof and breathable PTFE membrane with good waterproof performance and high mechanical strength. In this embodiment, the first fluid is a gas and the second fluid is a liquid. The pressures on both sides of the membrane 223 are different, and the liquid impacts the membrane 223 when flowing outside the diffusion layer 22. Therefore, the membrane 223 needs high mechanical strength to prevent the PTFE membrane from rupturing under the impact of the liquid.

[0051] Preferably, the air permeability of the PTFE membrane is 1-10 s / ml / inch. 2 Air permeability refers to the time required for a certain amount of gas to pass through a unit area of ​​membrane 223. That is, the PTFE membrane has a suitable pore structure, which allows the gas to have a large diffusion amount and a relatively uniform diffusion. The air permeability of the PTFE membrane and the diffusion coefficient of the diffusion zone are coordinated to ensure that the gas diffusion amount of the filter element meets the requirements.

[0052] The areal density of the membrane 223 of the present invention is 10-25 g / m³. 2The thickness is 20-150μm, which gives the membrane 223 a suitable support strength. In combination with the diffusion coefficient K in the above range, the deformation and recovery of the folds are achieved by the support force between adjacent folds. In combination with the support strength of the membrane itself, the folds will produce a certain degree of bending deformation. Under the impact of the liquid, the folds will continuously bend and stretch, so that the liquid flows to the diffusion layer 22 and fully contacts and mixes with the gas.

[0053] The diffusion layer 22 also includes a first support net 224 located on one side of the membrane 223 near the central rod 21 and a second support net 225 located on the other side of the membrane 223. The function of the second support net 225 and the first support net 224 is to support the membrane 223 so that it can form folds and effectively prevent adjacent folds from collapsing and blocking the flow channel of the diffusion region 222, so that the diffusion coefficient of the diffusion region 222 remains stable.

[0054] The thickness of the first support mesh 224 is greater than the thickness of the second support mesh 225. The mesh count of the second support mesh 225 is not less than 28 mesh, with small and dense pores, preferably in the range of 28-100 mesh. The thickness of the second support mesh 225 is 30-75 μm, and the areal density of the second support mesh 225 is 50-90 g / m². 2 The ratio of the thickness of the first support mesh 224 to the thickness of the second support mesh 225 is 1.2-3.6; the ratio of the areal density of the first support mesh 224 to the areal density of the second support mesh 225 is 1.4-4.4; the ratio of the mesh count of the second support mesh 225 to the first support mesh 224 is 1.1-2.5; the mesh count of the first support mesh 224 is 11-80 mesh, the pores are larger than those of the second support mesh; the thickness of the first support mesh 224 is 65-95 μm; and the areal density of the first support mesh 224 is 90-130 g / m³. 2 .

[0055] The first support net 224, the membrane 223, and the second support net 225 are stacked and folded in sequence to form folds. Due to the gaps between them, the first support net 224, the membrane 223, and the second support net 225 each have their own fold peaks and fold valleys, as shown in the attached figure. Figure 5 As shown, the length L1 of the second support net 225 refers to the radial length between the peaks and valleys of the second support net 225; the length L2 of the membrane body 223 refers to the radial length between the peaks and valleys of the membrane body 223; the length L2 of the first support net 224 refers to the radial length between the peaks and valleys of the first support net 224; and the lengths L1 of the second support net 225, L2 of the membrane body 223, and L3 of the first support net 224 satisfy the following formula: L1 > L2, and the value of L1-L2 is 10-25mm; L3 > L2, and the value of L3-L2 is 5-15mm.

[0056] The second support net 225 is located on the outer side of the membrane 223, away from the central rod 21, and L1 > L2, so that there is a certain radial distance between the second support net 225 and the membrane 223. Since the second support net 225 can extend with the direction of fluid flow, it can introduce fluid into the spaces between adjacent folds, thus having a guiding effect to increase the contact between liquid and gas, allowing the liquid to quickly carry away the gas, thereby increasing the gas diffusion. The value range of L1-L2 is important because if the value of L1-L2 is large, the second support net 225 will deform too much under the impact of liquid, and will easily accumulate at the fold positions of the membrane 223, thus blocking the gas diffusion channels; if the value of L1-L2 is small, the second support net 225 will have a smaller amplitude with the liquid flow, and will not be able to play a guiding role, thus reducing the gas diffusion.

[0057] The first support net 224 is located inside the membrane 223, near the central rod, and L3 > L2, resulting in a certain radial distance between the first support net 224 and the membrane 223. The value range of L1-L2 is used so that when the membrane 223 and the second support net 225 are impacted by liquid, they deform towards the first support net 224. The first support net 224 deforms under the impact force, and the radial distance provides space for the membrane 223 to deform. The first support net 224 can also buffer and support the membrane 223. The value range of L3-L2 is used so that when gas hits... When the gas impacts the first support net 224, it acts as a buffer to prevent eddies from forming, thereby increasing the resistance of the gas through the waterproof and breathable membrane and reducing the amount of gas diffusion. If the value of L3-L2 is large, the first support net 224 will not be able to adequately restrict the deformation of the membrane 223. When the membrane 223 is subjected to a large impact and undergoes a large deformation, it is prone to rupture. If the value of L3-L2 is small, it will reduce the deformation of the membrane 223, failing to achieve a good drainage effect and failing to buffer the gas flow. This will cause eddies to form near the membrane 223, thereby reducing the amount of gas diffusion.

[0058] As attached Figure 2 As shown, the end of the outer shell 1 that is sealed and fixedly connected to the top cover 11 is the first end 15, and the end with the outlet 14 is the second end 16. The inner diameter D of the outer shell 1 decreases gradually from the first end 15 to the second end 16. The formula for the gradient change ΔD of the inner diameter of the outer shell 1 is: ΔD = (D1-D2) / N, where D1 is the inner diameter of the first end, D2 is the inner diameter of the second end, N is the length of the outer shell, and ΔD is the range of the outer shell.

[0059] The filter element assembly 2 is disposed inside the outer shell 1. The filter element assembly 2 is a column with one end close to the first end 15 of the outer shell 1 and the other end close to the second end 16 of the outer shell 1. Since the inner diameter of the outer shell 1 decreases gradually from the first end 15 to the second end 16, the distance between the filter element assembly 2 and the inner wall of the outer shell 1 also decreases gradually from the first end 15 to the second end 16. As a result, the hydraulic pressure between the filter element assembly 2 and the inner wall of the outer shell 1 gradually increases from the first end 15 to the second end 16. During the gas-liquid mixing process, as the liquid moves towards the outlet 14, the gradually increasing hydraulic pressure can prevent small bubbles that have not dissolved in time from agglomerating into large bubbles. Large bubbles moving upwards can cause uneven pressure inside the device. At the same time, it can also prevent the solution concentration from increasing and the gas from evaporating from the liquid as the liquid moves towards the outlet 14 during the gas-liquid mixing process. In this embodiment, the range of △D makes the hydraulic pressure difference between the first end 15 and the second end 16 of the outer casing 1 more reasonable, and can also control the inner diameter of the second end 16, so as to avoid the liquid from stagnating at the outlet 14 due to the inner diameter of the second end 16 being too small, forming a vortex, and thus blocking the outlet 14.

[0060] Based on the parameters of each component of the above-mentioned gas-liquid mixing device, the present invention provides the following embodiments and comparative examples.

[0061] In Example 1, the first fluid is ammonia, the second fluid is deionized water, and the diffusion layer includes a membrane, a first support mesh located on the side of the membrane near the central rod, and a second support mesh located on the other side of the membrane. The membrane is a waterproof and breathable PTFE membrane with a permeability of 5 s / ml / inch. 2 The fold height H in the diffusion zone is 5 mm, the fold spacing C / M is 1 mm, the diffusion coefficient K in the diffusion zone is 5, the mesh size of the second support mesh is 30 mesh, and the surface density is 50 g / m³. 2 The thickness is 50μm, the first support mesh has a mesh count of 15 mesh, and the surface density is 100g / m³. 2 The thickness is 70μm.

[0062] In Example 2, the first fluid is ammonia, the second fluid is deionized water, and the diffusion layer includes a membrane, a first support mesh located on the side of the membrane near the central rod, and a second support mesh located on the other side of the membrane. The membrane is a waterproof and breathable PTFE membrane with a permeability of 5 s / ml / inch. 2 The fold height H in the diffusion zone is 10 mm, the fold spacing C / M is 0.7 mm, the diffusion coefficient K in the diffusion zone is 7, the mesh size of the second support mesh is 30 mesh, and the surface density is 50 g / m³. 2 The thickness is 50μm, the first support mesh has a mesh count of 15 mesh, and the surface density is 100g / m³. 2 The thickness is 70μm.

[0063] In Example 3, the first fluid is ammonia, the second fluid is deionized water, and the diffusion layer includes a membrane, a first support mesh located on the side of the membrane near the central rod, and a second support mesh located on the other side of the membrane. The membrane is a waterproof and breathable PTFE membrane with a permeability of 5 s / ml / inch. 2 The fold height H in the diffusion zone is 10 mm, the fold spacing C / M is 0.5 mm, the diffusion coefficient K in the diffusion zone is 5, the mesh size of the second support mesh is 30 mesh, and the surface density is 50 g / m³. 2 The thickness is 50μm, the first support mesh has a mesh count of 15 mesh, and the surface density is 100g / m³. 2 The thickness is 70μm.

[0064] Example 4: The first fluid is ammonia, the second fluid is deionized water, and the diffusion layer includes a membrane, a first support mesh located on the side of the membrane near the central rod, and a second support mesh located on the other side of the membrane. The membrane is a waterproof and breathable PTFE membrane with a permeability of 5 s / ml / inch. 2 The fold height H in the diffusion zone is 10 mm, the fold spacing C / M is 0.95 mm, the diffusion coefficient K in the diffusion zone is 9.5, the mesh size of the second support mesh is 30 mesh, and the surface density is 50 g / m³. 2 The thickness is 50μm, the first support mesh has a mesh count of 15 mesh, and the surface density is 100g / m³. 2 The thickness is 70μm.

[0065] Comparative Example 1: The first fluid is ammonia, the second fluid is deionized water, and the diffusion layer includes a membrane, a first support mesh located on the side of the membrane near the central rod, and a second support mesh located on the other side of the membrane. The membrane is a waterproof and breathable PTFE membrane with a permeability of 5 s / ml / inch. 2 The fold height H in the diffusion zone is 2.5 mm, the fold spacing C / M is 0.1 mm, the diffusion coefficient K in the diffusion zone is 0.25, the mesh size of the second support mesh is 30 mesh, and the surface density is 50 g / m³. 2 The thickness is 50μm, the first support mesh has a mesh count of 15 mesh, and the surface density is 100g / m³. 2 The thickness is 70 μm. Compared with Example 1, Comparative Example 1 has a lower diffusion coefficient K, resulting in a lower solution concentration and uneven solution concentration.

[0066] Comparative Example 2: The first fluid is ammonia, the second fluid is deionized water, and the diffusion layer includes a membrane, a first support mesh located on the side of the membrane near the central rod, and a second support mesh located on the other side of the membrane. The membrane is a waterproof and breathable PTFE membrane with a permeability of 5s / ml / inch. 2The fold height H in the diffusion zone is 10 mm, the fold spacing C / M is 4 mm, the diffusion coefficient K in the diffusion zone is 40, the mesh size of the second support mesh is 30 mesh, and the surface density is 50 g / m³. 2 The thickness is 50μm, the first support mesh has a mesh count of 15 mesh, and the surface density is 100g / m³. 2 The thickness is 70 μm. Compared with Example 2, Comparative Example 2 has an increased diffusion coefficient K, resulting in a lower solution concentration and uneven solution concentration.

[0067] Comparative Example 3: The first fluid is ammonia, the second fluid is deionized water, and the diffusion layer includes a membrane, a first support mesh located on the side of the membrane near the central rod, and a second support mesh located on the other side of the membrane. The membrane is a waterproof and breathable PTFE membrane with a permeability of 15 s / ml / inch. 2 The fold height H in the diffusion zone is 5 mm, the fold spacing C / M is 1 mm, the diffusion coefficient K in the diffusion zone is 5, the mesh size of the second support mesh is 30 mesh, and the surface density is 50 g / m³. 2 The thickness is 50μm, the first support mesh has a mesh count of 15 mesh, and the surface density is 100g / m³. 2 The thickness is 70 μm. Compared with Example 1, the comparative example three has increased PTFE membrane permeability, resulting in lower solution concentration and uneven solution concentration.

[0068] Comparative Example 4: The first fluid is ammonia, the second fluid is deionized water, and the diffusion layer includes a membrane, a first support mesh located on the side of the membrane near the central rod, and a second support mesh located on the other side of the membrane. The membrane is a waterproof and breathable PTFE membrane with a permeability of 15 s / ml / inch. 2 The fold height H in the diffusion zone is 10 mm, the fold spacing C / M is 1.5 mm, the diffusion coefficient K in the diffusion zone is 15, the mesh size of the second support mesh is 30 mesh, and the surface density is 50 g / m³. 2 The thickness is 50μm, the first support mesh has a mesh count of 15 mesh, and the surface density is 100g / m³. 2 The thickness is 70 μm. Compared with Example 3, Comparative Example 4 has increased air permeability and diffusion coefficient K of the PTFE membrane, resulting in lower solution concentration and uneven solution concentration.

[0069] Comparative Example 5: The first fluid is ammonia, the second fluid is deionized water, and the diffusion layer includes a membrane, a first support mesh located on the side of the membrane near the central rod, and a second support mesh located on the other side of the membrane. The membrane is a waterproof and breathable PTFE membrane with a permeability of 5 s / ml / inch. 2 The fold height H in the diffusion zone is 5 mm, the fold spacing C / M is 1 mm, the diffusion coefficient K in the diffusion zone is 5, the mesh size of the second support mesh is 15 mesh, and the surface density is 40 g / m³. 2The thickness is 30μm, the first support mesh has a mesh count of 30 mesh, and the areal density is 140g / m³. 2 The thickness is 100 μm. In Comparative Example 5, compared to Example 1, the mesh count of the second support mesh is reduced, making the mesh count of the first support mesh greater than that of the second support mesh, resulting in a lower solution concentration and uneven solution concentration.

[0070] This invention prepared ammonia solution with a concentration of 26%. The concentration of ammonia solution flowing from outlet 14 was measured every 5 minutes during the 10-35 minute operation of the apparatus. Based on experimental observations, the ammonia concentration (%) of each example at different times is shown in Table 1. Table 1 10min 26 26.1 25.8 25.5 15.3 12 19.6 18.4 21 15min 25 25.7 25.9 26.3 16.2 13.4 20.2 18.7 20.5 20min 26 26.3 25.7 26.7 15.7 13.9 20.4 17.5 21.2 25min 26 25.9 26 25.8 14.3 12.4 18.4 17.1 19.4 30min 25.3 25.8 26.3 25.9 15.9 11.2 17.2 16.4 18.6 35min 26.7 26 25.9 26.4 16.9 10.3 16.3 15 16 As shown in Table 1, the ammonia concentrations measured in Examples 1-4 were relatively uniform within 10-35 minutes of device operation, while the ammonia concentrations measured in Comparative Examples 1-5 were extremely uneven within 10-35 minutes of device operation, and some even showed a low concentration of prepared ammonia.

[0071] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A gas-liquid mixing device, comprising a housing and a filter element assembly located within the housing, wherein a top cover is sealed to one end of the housing, the filter element assembly includes a central rod with a porous structure and a folded diffusion layer surrounding the central rod, the top cover having a first inlet communicating with the central rod and a second inlet communicating with the housing, the first inlet being through which a first fluid is introduced to fill the central rod, the second inlet being through which a second fluid is introduced to fill the space between the diffusion layer and the housing, and the other end of the housing having an outlet, wherein the first fluid and the second fluid are in different phases, characterized in that: The folded diffusion layer forms several folds, with the fold valleys close to the central rod. Between two adjacent fold valleys, there is a diffusion zone for fluid diffusion. The diffusion coefficient K of the diffusion zone is 5-35. K is calculated by the following formula: K = H * C / M, where M is the number of diffusion zones, C is the outer circumference of the central rod, and H is the average fold height, which is 5-30 mm. The diffusion layer includes a membrane, which is a waterproof and breathable PTFE membrane with a permeability of 1-10 s / ml / inch. 2 ; The diffusion layer further includes a second support mesh and a first support mesh. The first support mesh is located on the side of the membrane body closer to the central rod, and the second support mesh is located on the other side of the membrane body. The mesh count ratio of the second support mesh to the first support mesh is 1.1-2.

5.

2. The gas-liquid mixing device as described in claim 1, characterized in that, The diffusion coefficient K of the diffusion region is 7-30.

3. The gas-liquid mixing device as described in claim 2, characterized in that, The areal density of the membrane is 10-25 g / m³ 2 The thickness of the membrane is 20-150 μm.

4. The gas-liquid mixing device as described in claim 2, characterized in that, The thickness of the first support mesh is greater than the thickness of the second support mesh.

5. The gas-liquid mixing device as described in claim 4, characterized in that, The ratio of the thickness of the first support mesh to the thickness of the second support mesh is 1.2-3.6; The ratio of the areal density of the first support mesh to the areal density of the second support mesh is 1.4-4.

4.

6. The gas-liquid mixing device as described in claim 5, characterized in that, The thickness of the first support mesh is 65-95 μm, and the areal density of the first support mesh is 90-130 g / m². 2 ; The thickness of the second support mesh is 30-75 μm, and the areal density of the second support mesh is 50-90 g / m². 2 .

7. The gas-liquid mixing device as described in claim 4, characterized in that, The length L1 of the second support mesh between the fold valley and the fold peak, the length L2 of the membrane body, and the length L3 of the first support mesh satisfy the following formula: L1 > L2, and the value of L1 - L2 is 10-25 mm; L3 > L2, and the value of L3 - L2 is 5-15 mm.

8. The gas-liquid mixing device as described in claim 4, characterized in that, The second support mesh has a mesh count of 28-100.

9. The gas-liquid mixing device as described in claim 1, characterized in that, The end of the outer shell that is sealed and fixedly connected to the top cover is the first end, and the end with the outlet is the second end. The inner diameter D of the outer shell decreases gradually from the first end to the second end.

10. The gas-liquid mixing device as described in claim 9, characterized in that, The gradient change ΔD of the inner diameter of the outer shell is 0.01-0.

06. ΔD is calculated by the following formula: ΔD=(D1-D2) / N, where D1 is the inner diameter of the first end, D2 is the inner diameter of the second end, and N is the length of the outer shell.

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