Absorption treatment device for water-soluble waste gas

Abstract

The utility model relates to a water-soluble waste gas absorption treatment device, which comprises: a packed tower, which sequentially comprises a gas inlet space, an unmodified wire mesh packing layer, a gas-liquid distributor, a modified wire mesh packing layer, a liquid distributor and a first exhaust port from bottom to top; the gas-liquid distributor comprises a liquid storage space, and a gas flow channel and a liquid flow channel which are arranged in the liquid storage space; the hydrophilicity of the modified metal wire mesh filler layer is greater than that of the unmodified metal wire mesh filler layer; one end of the solution circulating pump is communicated with the gas inlet space, the other end of the solution circulating pump is communicated with the gas-liquid distributor, and the solution circulating pump is used for conveying the solution in the gas inlet space into the liquid storage space; and the pure water input pipeline is communicated with the liquid distributor and is used for injecting pure water into the packed tower. The device can reduce the concentration of an organic solvent in final discharged gas, improves the concentration of a recovered solution, is high in environmental protection property and good in energy-saving effect, and reduces the subsequent treatment cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waste gas treatment, in particular to a water-soluble waste gas absorption treatment device. BACKGROUND

[0002] In the industrial production process, some chemical solvents are often used, and it is inevitable to produce waste gas containing these chemical solvents during the production process. On the one hand, these chemical solvents are not easy to degrade, which affects the environment and may have certain toxicity, so the concentration of chemical solvents in waste gas needs to be controlled below a certain standard before being discharged. On the other hand, these chemical solvents have good economic value and need to be recycled for reuse.

[0003] Some chemical solvents have the property of being able to dissolve with pure water in any proportion, such as N-methyl pyrrolidone, N,N-dimethylacetamide, etc. At present, the traditional absorption tower is often used in industrial production to treat waste gas. Taking N-methyl pyrrolidone as an example, which is abbreviated as NMP, the traditional method uses a packed tower to circulate NMP solution to absorb tail gas. However, due to the physical properties of NMP solution, even if complete thermodynamic equilibrium is achieved, NMP components will always exist in the tail gas after NMP solution absorption. Although it can meet the general emission standard, the concentration of NMP in the tail gas is still relatively high in some high-standard areas. The group standard "Lithium-ion battery industry NMP waste gas emission accounting and control technology guide" investigation points out that the domestic NMP emission concentration level is 5~10mg / m 3 .

[0004] Since NMP can be mixed with water in any proportion, using pure water can reduce the NMP concentration in the waste gas to a lower level, and the NMP component can be reduced to 1mg / m 3 . However, according to the requirements of the traditional metal wire mesh packing layer, the spray density of the liquid phase needs to reach 0.2m 3 / (m 2 .h) or more to ensure the wetting of the metal wire mesh packing layer, so as to ensure the absorption effect of NMP. This results in the concentration of the final NMP recovery solution being too low, which can only reach about 40%~50%. Subsequent purification treatment of the low-concentration NMP recovery solution is required, which increases energy consumption and cost.

[0005] In summary, in the recovery and treatment process of waste gas containing N-methyl pyrrolidone, N,N-dimethylacetamide, etc., it is necessary to reduce the concentration of organic solvents in the final exhaust gas and increase the concentration of the recovery liquid. CONTENT OF THE INVENTION

[0006] Therefore, it is necessary to provide a water-soluble waste gas absorption treatment device, and the specific technical scheme is as follows.

[0007] A water-soluble waste gas absorption treatment device comprises:

[0008] The packing tower comprises, from bottom to top, an air inlet space, an unmodified metal mesh packing layer, a gas-liquid distributor, a modified metal mesh packing layer, a liquid distributor, and a first air outlet; the gas-liquid distributor comprises a liquid storage space, and a gas flow channel and a liquid flow channel arranged in the liquid storage space; the modified metal mesh packing layer has a higher hydrophilicity than the unmodified metal mesh packing layer;

[0009] A solution circulating pump is in communication with the air inlet space at one end and the gas-liquid distributor at the other end, and is used to deliver the solution in the air inlet space to the liquid storage space;

[0010] A pure water input pipeline is in communication with the liquid distributor, and is used to inject pure water into the packing tower.

[0011] Further, the static water contact angle of the surface of the unmodified metal mesh packing layer is between 70° and 80°; and the static water contact angle of the modified metal mesh packing layer is between 0° and 15°.

[0012] Further, a heat exchanger is arranged between the solution circulating pump and the gas-liquid distributor.

[0013] Further, the liquid storage space comprises an outer wall and a bottom wall;

[0014] The gas flow channel comprises a first pipe body; the first pipe body is connected with the bottom wall, one end of the first pipe body extends downward through the bottom wall and is provided with a second air inlet at the bottom, and the other end of the first pipe body extends upward through the bottom wall and is blocked at the top; a second air outlet is arranged on the side of the first pipe body, and the second air outlet is higher than the bottom wall;

[0015] The liquid flow channel comprises a second pipe body; the second pipe body is connected with the bottom wall, one end of the second pipe body extends downward through the bottom wall and is provided with a second liquid outlet at the bottom, and the other end of the second pipe body extends upward through the bottom wall and is blocked at the top; a liquid inlet is arranged on the side of the second pipe body, and the liquid inlet is higher than the bottom wall.

[0016] Further, an overflow port is arranged below the second air outlet.

[0017] Further, the second pipe body comprises a main body and an enlarged head; the enlarged head is connected to the end of the main body; the liquid inlet is arranged on the side of the enlarged head; the minimum radial cross section of the pipe body is S1, the total opening area of the liquid inlet is S2, and the maximum radial cross section of the enlarged head is S3; S1:S2=1-2:1; S1:S3=1.3-3:1.

[0018] Further, the second liquid outlet is beveled, and the included angle between the bevel and the horizontal plane is 45°-60°.

[0019] Further, the plurality of gas flow channels are uniformly arranged around the center of the gas-liquid distributor in layers, and the plurality of liquid flow channels are arranged around each of the gas flow channels.

[0020] The water-soluble waste gas absorption treatment device provided by the utility model adopts a solution circulating pump to circulate high-concentration solution, thereby ensuring the wetting of the unmodified metal wire mesh filler layer. A modified metal wire mesh filler layer is arranged above the unmodified metal wire mesh filler layer, and pure water is used to wet the modified metal wire mesh filler layer, thereby improving the absorption effect on organic solvents in waste gas, reducing the concentration of organic solvents in the final exhaust gas, and achieving a concentration of 1 mg / m 3 The hydrophilicity of the modified metal wire mesh filler layer is improved, thereby reducing the requirement of the modified metal wire mesh filler layer for the spraying density, and the additional water in the treatment process only needs to meet the wetting requirement of the modified metal wire mesh filler layer, so that the overall additional water amount is small, the concentration of the final recovered solution is high and can reach more than 90%, the environmental protection performance is high, the energy-saving effect is good, and the subsequent treatment cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0022] Figure 1 It is a whole schematic view of the recovery treatment device;

[0023] Figure 2 It is a schematic view of the filler tower;

[0024] Figure 3 It is a schematic view of the gas-liquid distributor;

[0025] Figure 4 It is a top view of the gas-liquid distributor;

[0026] Figure 5 It is a state schematic view of the gas-liquid distributor;

[0027] Figure 6 It is a schematic view of the liquid flow channel.

[0028] The drawings are explained as follows: 1, NMP solution circulating pump; 2, pure water input pipeline; 3, air inlet space; 4, unmodified metal wire mesh filler layer; 5, gas-liquid distributor; 6, modified metal wire mesh filler layer; 7, liquid distributor; 8, first exhaust port; 9, demister;

[0029] 11, heat exchanger;

[0030] 31, first gas inlet; 32, first liquid outlet;

[0031] 51, liquid storage space; 52, first pipe body; 53, second gas inlet; 54, second liquid outlet; 55, second pipe body; 56, second liquid outlet; 57, liquid inlet; 58, overflow port; 59, enlarged head; 50, body;

[0032] 511, outer wall; 512, bottom wall. DETAILED DESCRIPTION

[0033] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways beyond the specific embodiments described and it is therefore contemplated to cover all such modifications as fall within the scope of the application. It is to be understood that the specific embodiments of the present application are shown by way of illustration and not as limitations.

[0034] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0035] In addition, the terms "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0036] In this application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "fixing" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrated; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0037] In this application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0038] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on another element or there can be a middle element. When an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and are not the only embodiment.

[0039] Embodiment

[0040] The embodiment provides a water-soluble waste gas absorption treatment device, referring to Figure 1 It is pointed out that the recovery treatment device provided by the embodiment can be applied to tail gas treatment and recovery of water-soluble solvents, such as N-methyl pyrrolidone, N,N-dimethylacetamide and the like. In the following embodiment, N-methyl pyrrolidone is taken as an example for description, and is uniformly referred to as NMP.

[0041] Specifically, referring to Figure 2As shown, the packing tower includes, from bottom to top, an air inlet space 3, an unmodified metal mesh packing layer 4, a gas-liquid distributor 5, a modified metal mesh packing layer 6, a liquid distributor 7, and a first air outlet 8. The first air outlet 8 is located at the top, and in an embodiment, organic solvent NMP is used as an example for illustration. The exhaust gas containing NMP flows upward from the bottom of the packing tower and is discharged from the first air outlet 8 after treatment. The gas-liquid distributor 5 includes a liquid storage space 51, and a gas flow channel and a liquid flow channel arranged in the liquid storage space 51. The liquid storage space 51 can store a certain amount of liquid, and the liquid in the liquid storage space 51 can flow to the unmodified metal mesh packing layer 4 through the liquid flow channel, and the exhaust gas passing through the unmodified metal mesh packing layer 4 flows upward through the gas flow channel. The modified metal mesh packing layer 6 has a higher hydrophilicity than the unmodified metal mesh packing layer 4, and requires a smaller spraying density to wet the modified metal mesh packing layer 6, that is, the modified metal mesh packing layer 6 requires a smaller amount of water during operation. By reducing the spraying density required by the modified metal mesh packing layer 6, the overall amount of additional water during the treatment process is reduced, and the concentration of the recovered NMP solution is increased.

[0042] Specifically, with continued reference to Figure 1 As shown, one end of the NMP solution circulating pump 1 is in communication with the air inlet space 3, and the other end is in communication with the gas-liquid distributor 5, for conveying the NMP solution in the air inlet space 3 to the liquid storage space 51. The air inlet space 3 is located below the unmodified metal mesh packing layer 4, and the high-concentration NMP exhaust gas enters the unmodified metal mesh packing layer 4 to exchange mass with the liquid, to obtain a high-concentration NMP solution, which enters the air inlet space 3 and is pumped by the solution circulating pump 1 to the gas-liquid distributor 5, to mix with the low-concentration NMP solution falling from the modified metal mesh packing layer 6, and the mixed solution in the gas-liquid distributor 5 enters the unmodified metal mesh packing layer 4 through the liquid flow channel to exchange mass with the NMP exhaust gas. By conveying the NMP solution in the air inlet space 3 to the gas-liquid distributor 5, the spraying density of the unmodified metal mesh packing layer 4 is actually increased, thereby meeting the wetting requirements of the unmodified metal mesh packing layer 4.

[0043] Specifically, the pure water input pipeline 2 is in communication with the gas-liquid distributor 5, for injecting pure water into the packing tower. During the treatment process, the pure water input pipeline 2 is the only source of additional water for the packing tower, and only needs to meet the spraying density of the modified metal mesh packing layer 6, so that the amount of additional water can be reduced, the concentration of the recovered NMP solution is ensured, and the concentration of the recovered NMP solution can be more than 90%. The use of pure water can dissolve NMP at any ratio, so that after the exhaust gas exchanges mass with the pure water and is discharged, the NMP concentration in the final exhaust gas can be greatly reduced, and the NMP content can be less than 1 mg / m 3The following meets the requirements of the European high emission standard.

[0044] It should be noted that, due to the relatively high hydrophilicity of the modified metal wire mesh filler layer 6, a dry environment can damage the hydrophilicity of the modified metal wire mesh filler layer 6, making its wettability worse, thereby negatively affecting the absorption effect of NMP. NMP exhaust gas usually has the characteristics of high temperature and low humidity. For example, after the positive electrode coating of a lithium battery is completed, drying is required. NMP is evaporated by hot air baking of the coated pole piece, generating exhaust gas containing NMP, which has relatively high temperature and relatively low humidity. In order to avoid the direct contact of the too dry exhaust gas with the modified metal wire mesh filler layer 6 from affecting the hydrophilicity of the modified metal wire mesh filler layer 6, the exhaust gas is first passed through the unmodified metal wire mesh filler layer 4 to be fully wetted, and then enters the modified metal wire mesh filler layer 6.

[0045] It should be noted that the pure water referred to in this embodiment does not mean water completely free of impurities, but water containing no NMP component, i.e. pure water can dissolve NMP in any proportion.

[0046] The water-soluble exhaust gas absorption treatment device provided in this embodiment uses a solution circulating pump to circulate high-concentration solution, ensuring the wetting of the unmodified metal wire mesh filler layer. The modified metal wire mesh filler layer is arranged above the unmodified metal wire mesh filler layer, and pure water is used to wet the modified metal wire mesh filler layer to improve the absorption effect of organic solvents in the exhaust gas, reduce the concentration of organic solvents in the final exhaust gas, and achieve a concentration of 1 mg / m 3 The following; improve the hydrophilicity of the modified metal wire mesh filler layer, thereby reducing the requirement of the modified metal wire mesh filler layer for the spraying density, and the additional water in the treatment process only needs to meet the wetting requirement of the modified metal wire mesh filler layer. The overall amount of additional water is small, the concentration of the final recovered solution is high, can reach more than 90%, the environmental protection performance is high, the energy saving effect is good, and the subsequent treatment cost is reduced.

[0047] Specifically, the hydrophilicity of the modified metal wire mesh filler layer 6 and the unmodified metal wire mesh filler layer 4 can be described by the static water contact angle. The smaller the static water contact angle, the higher the hydrophilicity. In this embodiment, the static water contact angle of the surface of the unmodified metal wire mesh filler layer 4 is between 70° and 80°; the static water contact angle of the modified metal wire mesh filler layer is 0°. In the actual production process, under the condition of maintaining a wet environment, after the modified metal wire mesh filler layer 6 is in contact with the exhaust gas containing NMP for a period of time, i.e. after a period of production and treatment, the final static water contact angle of the modified metal wire mesh filler layer 6 stabilizes at 15°, which is much smaller than the static water contact angle of the unmodified metal wire mesh filler layer 4 and much lower than the requirement of the unmodified metal wire mesh filler layer 4 for the spraying density.

[0048] Specifically, the modification method of the modified metal wire mesh packing layer 6 has various methods, such as chemical etching and chemical oxidation method, laser processing method, electrochemical method, sol-gel method, etc., but most of the methods have the disadvantages of high cost, difficult to control, complex process, etc. The chemical etching and chemical oxidation method has the advantages of low cost and strong controllability, and the specific steps are as follows:

[0049] Firstly, the metal wire mesh packing in the metal wire mesh packing layer is washed with ethyl acetate or other organic solvents to remove the grease;

[0050] Secondly, the metal wire mesh packing is washed with clean water;

[0051] Thirdly, a 2mol / L FeCl3 solution is prepared and mixed with HCl and H2O2 according to a volume ratio of 15:1:1 to obtain an etching solution to etch the metal wire mesh packing;

[0052] Fourthly, the metal wire mesh packing is washed with clean water after the chemical etching is completed;

[0053] Fifthly, a mixed solution of CrO3 and H2SO4 is used as the oxidation solution to oxidize the metal wire mesh packing, the mass concentration of CrO3 is 250g / L, the mass concentration of H2SO4 is 500g / L, the oxidation temperature is 70-75℃, and the oxidation time is 8min;

[0054] Sixthly, the metal wire mesh packing is washed after the oxidation of the packing is completed.

[0055] The chemical etching-oxidation method is used to modify the hydrophilicity of the metal wire mesh packing, so that the static water contact angle of the surface of the metal wire mesh packing reaches 0°.

[0056] Specifically, referring to FIG. 1, Figure 1 The first gas inlet 31 and the first liquid outlet 32 are arranged in the gas inlet space 3, and the first liquid outlet 32 is located below the first gas inlet 31. The waste gas containing NMP is input into the gas inlet space 3 through the first gas inlet 31, so that the waste gas flows to the first gas outlet 8 at the top of the packing tower. The high-concentration NMP solution in the gas inlet space 3 is recovered through the first liquid outlet 32.

[0057] Specifically, referring to FIG. 1, Figure 2 As shown in FIG. 1, a defoamer 9 is further arranged between the first gas outlet 8 and the modified metal wire mesh packing layer 6. After the waste gas is treated by the modified metal wire mesh packing layer 6, a small amount of liquid phase components entrained by the waste gas are removed by the defoamer 9, and then the waste gas is discharged outward through the first gas outlet 8.

[0058] Specifically, the heat exchanger 11 is arranged between the solution circulating pump 1 and the gas-liquid distributor 5. The temperature of the NMP solution delivered into the gas-liquid distributor 5 from the intake space 3 can be adjusted by the heat exchanger 11. When the temperature of the exhaust gas input into the intake space 3 is too low, the temperature of the high-concentration NMP solution obtained in the intake space 3 after passing through the unmodified wire mesh packing layer 4 will decrease, and the temperature of the NMP solution delivered into the gas-liquid distributor 5 can be increased by the heat exchanger 11 to control the temperature balance. Conversely, when the temperature of the exhaust gas input into the intake space 3 is too high, the temperature of the NMP solution can also be decreased by the heat exchanger 11.

[0059] Specifically, referring to Fig. 1, the liquid storage space 51 includes an outer wall 511 and a bottom wall 512. The liquid storage space 51 surrounded by the outer wall 511 and the bottom wall 512 can store the low-concentration NMP solution flowing down after the mass transfer of the pure water in the modified packing and the low-concentration NMP exhaust gas, and provide a mixing space for the low-concentration NMP solution and the high-concentration NMP solution delivered from the intake space 3. Figure 3

[0060] Referring to Figs. 1 and 2, the gas flow channel includes a first pipe body 52. The first pipe body 52 is connected with the bottom wall 512, one end of the first pipe body 52 extends downward through the bottom wall 512 and is provided with a second gas inlet 53 at the bottom, and the other end of the first pipe body 52 extends upward through the bottom wall 512 and is blocked at the top. The side surface of the first pipe body 52 is provided with a second gas outlet 54, and the second gas outlet 54 is higher than the bottom wall 512. The liquid flow channel includes a second pipe body 55. The second pipe body 55 is connected with the bottom wall 512, one end of the second pipe body 55 extends downward through the bottom wall 512 and is provided with a second liquid outlet 56 at the bottom, and the other end of the second pipe body 55 extends upward through the bottom wall 512 and is blocked at the top. The side surface of the second pipe body 55 is provided with a liquid inlet 57, and the liquid inlet 57 is higher than the bottom wall 512. By blocking the top of the first pipe body 52 and the second pipe body 55, the liquid flowing down in the modified wire mesh packing layer 6 can be prevented from directly entering the gas flow channel or the liquid flow channel. By arranging the liquid inlet 57 to be higher than the bottom wall 512, the mixed solution in the liquid storage space 51 can flow downward into the liquid flow channel after the liquid surface of the mixed solution in the liquid storage space 51 is higher than the liquid inlet 57. Figure 4 Figure 5 It should be noted that the height of the second gas outlet 54 is higher than the liquid inlet 57, so that the liquid can be prevented from entering the gas flow channel from the second gas outlet 54. In addition, the first pipe body 52 is further provided with an overflow port 58, and the height of the overflow port 58 is lower than the second gas outlet 54 and higher than the liquid inlet 57. When the liquid inlet 57 is blocked, the liquid can be discharged downward through the overflow port 58.

[0061] It should be noted that a plurality of gas flow channels and a plurality of liquid flow channels are arranged in the embodiment. Referring to Figs. 1 and 2, the gas flow channel includes a first pipe body 52. The first pipe body 52 is connected with the bottom wall 512, one end of the first pipe body 52 extends downward through the bottom wall 512 and is provided with a second gas inlet 53 at the bottom, and the other end of the first pipe body 52 extends upward through the bottom wall 512 and is blocked at the top. The side surface of the first pipe body 52 is provided with a second gas outlet 54, and the second gas outlet 54 is higher than the bottom wall 512. The liquid flow channel includes a second pipe body 55. The second pipe body 55 is connected with the bottom wall 512, one end of the second pipe body 55 extends downward through the bottom wall 512 and is provided with a second liquid outlet 56 at the bottom, and the other end of the second pipe body 55 extends upward through the bottom wall 512 and is blocked at the top. The side surface of the second pipe body 55 is provided with a liquid inlet 57, and the liquid inlet 57 is higher than the bottom wall 512. By blocking the top of the first pipe body 52 and the second pipe body 55, the liquid flowing down in the modified wire mesh packing layer 6 can be prevented from directly entering the gas flow channel or the liquid flow channel. By arranging the liquid inlet 57 to be higher than the bottom wall 512, the mixed solution in the liquid storage space 51 can flow downward into the liquid flow channel after the liquid surface of the mixed solution in the liquid storage space 51 is higher than the liquid inlet 57.

[0062] It should be noted that a plurality of gas flow channels and a plurality of liquid flow channels are arranged in the embodiment. Referring to Figs. 1 and 2, the gas flow channel includes a first pipe body 52. The first pipe body 52 is connected with the bottom wall 512, one end of the first pipe body 52 extends downward through the bottom wall 512 and is provided with a second gas inlet 53 at the bottom, and the other end of the first pipe body 52 extends upward through the bottom wall 512 and is blocked at the top. The side surface of the first pipe body 52 is provided with a second gas outlet 54, and the second gas outlet 54 is higher than the bottom wall 512. The liquid flow channel includes a second pipe body 55. The second pipe body 55 is connected with the bottom wall 512, one end of the second pipe body 55 extends downward through the bottom wall 512 and is provided with a second liquid outlet 56 at the bottom, and the other end of the second pipe body 55 extends upward through the bottom wall 512 and is blocked at the top. The side surface of the second pipe body 55 is provided with a liquid inlet 57, and the liquid inlet 57 is higher than the bottom wall 512. By blocking the top of the first pipe body 52 and the second pipe body 55, the liquid flowing down in the modified wire mesh packing layer 6 can be prevented from directly entering the gas flow channel or the liquid flow channel. By arranging the liquid inlet 57 to be higher than the bottom wall 512, the mixed solution in the liquid storage space 51 can flow downward into the liquid flow channel after the liquid surface of the mixed solution in the liquid storage space 51 is higher than the liquid inlet 57. Figure 4 ​​As shown, the plurality of gas flow channels are arranged in two circles around the center of the gas-liquid distributor 5, and the plurality of liquid flow channels are arranged around each gas flow channel, ensuring the uniformity of gas flow and liquid flow.

[0063] Specifically, referring to Figure 6 As shown, the second pipe body 55 includes a body 50 and an enlarged head 59; the enlarged head 59 is connected to the end of the body 50, and a transition slope is formed between the enlarged head 59 and the body 50, and the angle of the transition slope relative to the horizontal plane is 60°-75°; the liquid inlet 57 is arranged on the side surface of the enlarged head 59; the minimum radial cross section of the pipe body is S1, the total opening area of the liquid inlet 57 is S2, and the maximum radial cross section of the enlarged head 59 is S3; S1:S2=1-2:1; S1:S3=1.3-3:1. The side opening solves the defects of unstable liquid flow and large resistance.

[0064] In order to better make the liquid flow downward to the unmodified metal wire mesh filler layer 4, the second liquid outlet 56 is an inclined opening, and the angle between the inclined opening and the horizontal plane is 45°-60°.

[0065] Waste gas treatment process:

[0066] The NMP waste gas is continuously introduced into the gas inlet space 3 from the bottom, and the NMP waste gas flows in the direction of the first gas outlet 8;

[0067] The pure water is continuously injected into the liquid distributor 7 through the pure water input pipeline 2, so that the pure water flows through the modified metal wire mesh filler layer 6 to form a low-concentration NMP solution into the gas-liquid distributor 5;

[0068] The high-concentration NMP solution in the gas inlet space 3 is continuously transported into the gas-liquid distributor 5 by the solution circulating pump 1 to mix with the low-concentration NMP solution;

[0069] The mixed solution in the gas-liquid distributor 5 flows through the unmodified metal wire mesh filler layer 4 to form a high-concentration NMP solution.

[0070] It should be noted that during the waste gas treatment process, the processes of introducing NMP waste gas into the gas inlet space 3, injecting pure water into the liquid distributor 7, and transporting the high-concentration NMP solution in the gas inlet space 3 into the gas-liquid distributor 5 are continuously carried out, thereby forming a circulating treatment process.

[0071] Among them, the high-concentration NMP mixed solution that has flowed through the unmodified metal wire mesh filler layer 4 and flowed into the gas inlet space 3 has reached the concentration requirement for recovery, that is, the concentration of the high-concentration NMP solution in the gas inlet space 3 has reached more than 90%. During the treatment process, the high-concentration NMP solution at the bottom of the gas inlet space 3 is continuously recovered through the first liquid outlet 32.

[0072] Any combination of the technical features in the above-described embodiments can be made, and for the sake of brevity, not all possible combinations are described, however, it is to be understood that the application embraces all such possible combinations.

[0073] The above-described embodiments only express several implementation manners of the application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that, for ordinary skilled persons in the art, some modifications and improvements can be made without departing from the concept of the application, and these all belong to the protection scope of the application. Therefore, the patent protection scope of the application should be subject to the appended claims.

Claims

1. An absorption and treatment device for water-soluble waste gas, characterized in that, include: The packed tower, from bottom to top, includes an air inlet space, an unmodified metal wire mesh packing layer, a gas-liquid distributor, a modified metal wire mesh packing layer, a liquid distributor, and a first exhaust port; the gas-liquid distributor includes a liquid storage space, and gas and liquid channels disposed within the liquid storage space; the modified metal wire mesh packing layer has a higher hydrophilicity than the unmodified metal wire mesh packing layer. The solution circulation pump has one end connected to the air intake space and the other end connected to the gas-liquid distributor. It is used to transport the solution in the air intake space to the liquid storage space. The pure water inlet pipe is connected to the liquid distributor and is used to inject pure water into the packed tower.

2. The absorption and treatment device for water-soluble waste gas according to claim 1, characterized in that, The static water contact angle of the unmodified metal wire mesh filler layer is between 70° and 80°; the static water contact angle of the modified metal wire mesh filler layer is between 0° and 15°.

3. The absorption and treatment device for water-soluble waste gas according to claim 1, characterized in that, A heat exchanger is provided between the solution circulation pump and the gas-liquid distributor.

4. The absorption and treatment device for water-soluble waste gas according to claim 1, characterized in that, The liquid storage space includes an outer wall and a bottom wall; The gas flow channel includes a first pipe body; the first pipe body is connected to a bottom wall, one end extends downward through the bottom wall and has a second air inlet at the bottom, and the other end extends upward through the bottom wall and is sealed at the top; a second exhaust port is provided on the side of the first pipe body, and the second exhaust port is higher than the bottom wall; The liquid flow channel includes a second tube body; the second tube body is connected to the bottom wall, one end extends downward through the bottom wall and has a second drain port at the bottom, and the other end extends upward through the bottom wall and is sealed at the top; the side of the second tube body has a liquid inlet, which is higher than the bottom wall.

5. The absorption and treatment device for water-soluble waste gas according to claim 4, characterized in that, An overflow port is provided below the second exhaust port.

6. The absorption and treatment device for water-soluble waste gas according to claim 4, characterized in that, The second tube body includes a main body and an enlarged head; the enlarged head is connected to the end of the main body; the liquid inlet is located on the side of the enlarged head; the minimum radial section of the tube body is S1, the total opening area of ​​the liquid inlet is S2, and the maximum radial section of the enlarged head is S3; S1:S2=1~2:1; S1:S3 = 1.3 to 3:

1.

7. The absorption and treatment device for water-soluble waste gas according to claim 4, characterized in that, The second drain outlet is an oblique opening, and the angle between the oblique opening and the horizontal plane is 45° to 60°.

8. The absorption and treatment device for water-soluble waste gas according to claim 4, characterized in that, It includes multiple gas channels and multiple liquid channels; the multiple gas channels are arranged uniformly layer by layer around the center of the gas-liquid distributor; the multiple liquid channels are arranged around each gas channel respectively.

Images