Device and method for testing durability of super-hydrophilic structured packing coating

Abstract

The invention discloses durability testing equipment for a super-hydrophilic structured packing coating. The equipment comprises a cylindrical tower, a first temperature measuring instrument, a first pressure measuring instrument, a second temperature measuring instrument, a second pressure measuring instrument, a third temperature control instrument, a liquid level control instrument, a first liquid storage tank, a second liquid storage tank, a vacuum pump and a heat exchanger. The method and the equipment can determine the stability and the service life of the structured packing with different coatings, and can be applied to the chemical fields of rectification, reaction and the like.

Description

Technical Field

[0001] The invention relates to the technical field of functional material testing, in particular to a durability test and method for a super-hydrophilic structured filler coating. Background Art

[0002] The application of structured packing in chemical production processes has become very common, especially in large-scale packed tower equipment. Its uniform and symmetrical geometric structure enables the formation of uniform and regular gas-liquid channels in the packed tower, greatly reducing the occurrence of abnormal flow phenomena such as channel flow, bias flow, wall flow, etc. in the tower, and also avoiding the occurrence of bridging, cavitation and other phenomena. Structured packing increases the contact area between the gas and liquid phases on the surface of the packing layer, and improves the flow behavior and contact mode of the gas and liquid phases in the packing layer. At present, vertical metal corrugated plate structured packing is the most widely used structured packing in chemical production processes. It is machined from metal sheet monomers. The thickness of each metal sheet is only about 0.2mm. Adjacent metal corrugated sheets are arranged alternately to form a corrugated channel. The gas and liquid phases contact each other in the corrugated channel for mass transfer and heat transfer. The specifications of the corrugated packing sheets involve: peak height (h), width between two adjacent peaks (b o ), the inclination angle between the corrugation and the vertical direction (γ). The structure of the corrugated plate packing is composed of h, b o The three parameters of γ and γ are jointly determined. When the values ​​of these three parameters change, many different structures and models of corrugated plate structured packing will be produced. At the same time, the corrugation inclination angle γ, peak height h and peak width b o It not only directly affects the pressure drop of the entire packing layer, but also affects the hydraulic properties of the packing. In order to enhance the flow state of the liquid phase on the packing surface and improve the mass transfer and heat transfer effect between the gas and liquid phases, a certain specific structure is often stamped out on the surface of the corrugated packing sheet. This special surface texture structure is also an important feature of metal corrugated packing.

[0003] At present, many studies have shown that structured packings with specially treated surfaces exhibit excellent separation effects in chemical separation processes. However, these studies focus on how to improve the separation effect of structured packings through surface modification, and the durability of the coating formed by surface modification has not been discussed in depth.

[0004] Generally, taking the structured packing of heavy water distillation as an example, the performance of structured packing in the heavy water distillation process mainly includes the following two parts: (1) hydraulic properties: the packing should have large specific surface area, high porosity, small flow resistance, uniform gas-liquid distribution and anti-clogging characteristics to achieve the ideal separation efficiency; (2) physical and chemical stability: the packing is required to be durable, not easy to damage, insoluble in water or heavy water in the project, and will not cause pollution, so that the packing can be used for a long time. It can be seen that the stability of the packing is an important factor that determines the separation efficiency of the packing.

[0005] To this end, the present invention explores the durability of surface coatings of structured packings with different structures and compositions by regulating the flow rate and flushing temperature of flushing water, and finally explores a durability test method and test equipment for super-hydrophilic structured packing coatings. The method and equipment of the present invention can effectively carry out stability tests of structured packings, test whether structured packings meet engineering use requirements, evaluate the stability and performance parameter changes of structured packings in the later operation cycle, and guide engineering design. Summary of the invention

[0006] In order to test whether the stability of the structured packing coating meets the requirements of engineering use and effectively evaluate the stability and performance parameter changes of the structured packing coating during the operation cycle, the present invention provides a simple and effective durability testing method and equipment for super hydrophilic structured packing coating.

[0007] One of the purposes of the present invention is to provide a durability testing device for super hydrophilic structured packing coating, comprising:

[0008] The cylindrical tower has a layered grid inside, with 2 to 6 layers, a logistics inlet at the top and a logistics outlet at the bottom, and filters are set at the logistics inlet and the logistics outlet;

[0009] A first temperature measuring instrument is disposed at the top of the cylindrical tower and is used to measure the temperature of the top of the cylindrical tower where the filler is flushed;

[0010] A first pressure measuring instrument is arranged at the top of the cylindrical tower and is used to measure the pressure at the top of the cylindrical tower where the filler is flushed;

[0011] A second temperature measuring instrument is disposed in the cylindrical tower and is used to measure the temperature in the cylindrical tower where the filler is flushed;

[0012] A second pressure measuring instrument is disposed in the cylindrical tower and is used to measure the pressure in the cylindrical tower where the filler is flushed;

[0013] A third temperature control instrument is provided in the cylindrical tower kettle, and is used to control the temperature of the cylindrical tower kettle for flushing the filler;

[0014] The liquid level control instrument is installed in the kettle of the cylindrical tower and is used to control the change of the liquid level of the cylindrical tower;

[0015] A first liquid storage tank, wherein an outlet is provided at the bottom of the first liquid storage tank, and the outlet is connected to the logistics inlet at the top of the cylindrical tower, and is the outlet for the flushing liquid to be discharged to the cylindrical tower. The top of the first liquid storage tank is not sealed, and serves as the inlet for the flushing liquid;

[0016] A second liquid storage tank, wherein the bottom of the second liquid storage tank is provided with an inlet, which is connected to the logistics outlet at the bottom of the cylindrical tower, so as to introduce the liquid discharged from the cylindrical tower into the tank;

[0017] A vacuum pump is disposed between the first liquid storage tank and the cylindrical tower, and is used to ensure that the flow rate of the flushing liquid entering the cylindrical tower is stable and controllable;

[0018] The heat exchanger is arranged between the vacuum pump and the cylindrical tower to ensure that the temperature of the flushing liquid entering the cylindrical tower is constant.

[0019] The main body of the durability testing device of the present invention can be a cylindrical distillation tower, which is used for water flushing of the surface coating of the structured packing. Preferably, the diameter of the cylindrical tower is 5 to 400 mm and the height is 400 to 3000 mm.

[0020] The cylindrical tower is provided with a multi-layered grid and a filter screen inside. The layered grid is used to fix the relative position of the structured packing in the tower, and the filter screen is used to filter impurities in the logistics.

[0021] The second object of the present invention is to provide a durability testing method for a super-hydrophilic structured packing coating, preferably using the durability testing equipment as described above, comprising the following steps:

[0022] (1) Soak the structured packing in water;

[0023] (2) placing the soaked structured packing on the layered grid of the durability test equipment, and after the system is stable, continue the flushing process with the flushing liquid, and stop heating;

[0024] (3) After the temperature of the cylindrical tower drops to room temperature, repeat step (2);

[0025] (4) After flushing, the structured packing is washed, dried, characterized, and tested for performance.

[0026] In the above technical solution, the structured packing is selected from structured packings of different sizes that are widely used in industry, including but not limited to at least one of wire mesh corrugated packing, perforated plate corrugated packing, perforated plate corrugated packing and plate mesh corrugated packing.

[0027] The surface of the structured packing has a specific coating, which is a copper oxide or copper hydroxide coating, and can be obtained by performing coating modification on the structured packing.

[0028] The copper purity of the structured filler before coating modification is 95-99.99wt%.

[0029] In the above technical solution, in step (1), the soaking time is 10 to 30 minutes and the soaking temperature is 5 to 70°C.

[0030] In the above technical solution, in step (2), the flushing liquid is deionized water.

[0031] In the above technical solution, the conductivity of deionized water is 0.1-1.0 μS·cm -1 .

[0032] In the above technical solution, the flushing liquid flow rate is 2 to 5 m 3 ·h -1 , for example, it can be 2m 3 ·h -1 、3m 3 ·h -1 、4m 3 ·h -1 、5m 3 ·h -1 wait.

[0033] In the above technical solution, the temperature of the flushing liquid is preferably 5 to 70° C., for example, 5° C., 10° C., 20° C., 30° C., 40° C., 50° C., 60° C., 70° C., etc. The flushing liquid is heated by a heat exchanger and the temperature is controlled by a temperature control, wherein the heating power is 25 to 45 kW.

[0034] In the above technical solution, in step (2), after the structured packing is loaded, the flushing liquid in the first liquid storage tank is passed into the cylindrical tower until the system is stable.

[0035] After the system is stable, the pressure in the cylindrical tower is 0.070-0.100 MPa, for example, it can be 0.070 MPa, 0.080 MPa, 0.090 MPa, 0.100 MPa, etc.; the temperature of the cylindrical tower is 5-70°C, for example, it can be 5°C, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, etc.

[0036] After the system is stable, the water storage capacity of the first liquid storage tank is maintained at 20% to 60% of its total volume, for example, it can be 20%, 30%, 40%, 50%, 60%, etc.

[0037] In the above technical solution, the flushing time is 1 to 12 hours, for example, it can be 1 hour, 3 hours, 5 hours, 8 hours, 10 hours, 12 hours, etc.

[0038] In the above technical solution, in step (3), the process of step (2) is repeated 5 to 150 times.

[0039] In the above technical solution, in step (4), the performance test includes observing the solid impurities in the obtained working fluid, testing the copper ion content in the structured filler and the obtained flushing fluid, the water contact angle of the filler after durability testing, the microscopic morphology of the coating, etc.

[0040] The present invention explores the durability of surface coatings of different structures and compositions of structured packing by regulating the flow rate and flushing temperature of flushing water, and finally explores a simple and easy-to-operate durability test method and test equipment for super-hydrophilic structured packing coatings. The different amounts of solid impurities generated by the super-hydrophilic structured packing before and after the durability test are observed by scanning with an optical microscope, the copper ion content in the structured packing and the flushing liquid is measured by inductively coupled plasma technology (ICP), and the morphological changes of the surface coating of the structured packing before and after water flushing are observed by scanning electron microscopy. The present invention also provides a durability test equipment for super-hydrophilic structured packing coatings that is simple in process and easy to industrialize.

[0041] The present invention has the following beneficial effects:

[0042] (1) The present invention proposes a durability test method for a super-hydrophilic structured packing coating, which has a simple process and is easy to scale up, and can be applied to test the service life of structured packing;

[0043] (2) The present invention proposes a durability testing device for super-hydrophilic structured packing coatings. The device is easy to scale up and can be used in durability testing of structured packing coatings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A flow chart of the test equipment proposed by the present invention;

[0045] Label description: V1001-first liquid storage tank, V1002-second liquid storage tank, P1001-vacuum pump, E1001-heat exchanger, TI1101-first temperature measuring instrument, TI1102-second temperature measuring instrument, TI1103-third temperature control instrument, PI1101-first pressure measuring instrument, PI1102-second pressure measuring instrument, LIC1101-liquid level control instrument, T1001-cylindrical tower;

[0046] Figure 2 Optical image of the working fluid flushing for CY700 wire mesh corrugated packing;

[0047] Figure 3 This is the optical microscope scanning result of solid impurities in the working fluid of CY700 wire mesh corrugated packing;

[0048] Figure 4 Scanning electron microscope images of CY700 wire mesh corrugated packing before and after scouring;

[0049] Figure 5 The hydrophilicity test results of CY700 wire mesh corrugated packing after flushing;

[0050] Figure 6 Optical image of the working fluid flushing for CY800 wire mesh corrugated packing;

[0051] Figure 7 This is the optical microscope scanning result of solid impurities in the working fluid of CY800 wire mesh corrugated packing;

[0052] Figure 8 Scanning electron microscope images of CY800 wire mesh corrugated packing before and after scouring;

[0053] Fig. 9 The hydrophilicity test results of CY800 wire mesh corrugated packing after flushing. DETAILED DESCRIPTION

[0054] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0055] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0056] According to a preferred embodiment of the present invention, the testing method comprises:

[0057] (1) Soaking the structured packing having a specific coating on the surface in deionized water at 5 to 70° C. for about 10 to 30 minutes;

[0058] (2) Place the soaked structured packing in a cylindrical tower and control the water flow rate to 2-5 m 3 ·h -1 , control the heating power to 25-45kW, and carry out the water flushing process;

[0059] (3) After the system is stable, continue flushing with deionized water for 1 to 10 hours and turn off the heating;

[0060] (4) After the temperature of the tower kettle drops to room temperature, repeat the water flushing process 5 to 150 times;

[0061] (5) After flushing, the obtained structured packing is washed, dried, and characterized and tested for performance to determine the stability of the structured packing coating.

[0062] In the above technical solution, steps (1) to (5) are preferably carried out at 5-70° C. and 0.070-0.100 MPa, which can simulate the working temperature of structured packing.

[0063] Example 1

[0064] According to one embodiment of the present invention, the durability testing equipment of the super hydrophilic regular packing coating includes a cylindrical tower T1001, the tower height is 2000 mm, the tower diameter is 300 mm, the cylindrical tower is provided with a 4-layered grid inside, the filter screen is placed at the logistics inlet and the logistics outlet, and also includes a first liquid storage tank V1001 and a second liquid storage tank V1002, the outlet at the lower end of the first liquid storage tank V1001 is connected to the logistics inlet at the top of the cylindrical tower T1001, the top of the first liquid storage tank V1001 is not sealed, and the lower end inlet of the second liquid storage tank V1002 is connected to the logistics outlet at the bottom of the cylindrical tower T1001. The cylindrical tower T1001 includes a first temperature measuring instrument TI1101 and a first pressure measuring instrument PI1101 arranged at the top of the cylindrical tower, a second temperature measuring instrument TI1102 and a second pressure measuring instrument PI1102 arranged in the cylindrical tower, a third temperature control instrument TI1103 and a liquid level control instrument LIC1101 arranged in the kettle of the cylindrical tower, a vacuum pump P1001 arranged between the first liquid storage tank and the cylindrical tower, and a heat exchanger E1001 arranged between the vacuum pump and the cylindrical tower.

[0065] The first temperature measuring instrument TI1101 and the first pressure measuring instrument PI1101, the second temperature measuring instrument TI1102 and the second pressure measuring instrument PI1102, and the third temperature control instrument TI1103 are used to measure the temperature and pressure of the installed position respectively, and the temperature and pressure are adjusted accordingly according to the results. The liquid level controller LIC1101 is used to control the liquid level change in the cylindrical tower.

[0066] Durability test of CY700 wire mesh corrugated packing (copper purity of structured packing before coating modification is 99wt%, with copper oxide coating on the surface):

[0067] (1) Soak the CY700 wire mesh corrugated packing with copper oxide coating in deionized water at a temperature of 30° C. for about 30 min, and blow dry with nitrogen for later use;

[0068] (2) The wetted structured packing treated in step (1) was placed in a durability test distillation tower at 40°C, with a conductivity of 0.5 μS·cm -1 The deionized water was used for flushing, and the flow rate of deionized water was controlled to be 4m 3 ·h -1 , control the heating power of the heat exchanger to 35kW. When the system is stable, the pressure is 0.1MPa, the water storage capacity of the first liquid storage tank is maintained at 35%, deionized water is flushed for 10 hours, and the heating is turned off;

[0069] (3) After the temperature of the tower bottom drops to room temperature, repeat steps (2) and (3) 12 times;

[0070] (4) Performing performance tests on the working fluid collected in the second fluid storage tank, including observing solid impurities in the working fluid, testing the copper ion content in the structured filler and the working fluid, the water contact angle of the filler after durability testing, and the microscopic morphology of the coating.

[0071] The optical image of the working fluid of the CY700 wire mesh corrugated packing after treatment is as follows Figure 2 As shown in the figure, it shows that after 10 hours of scouring, the copper oxide coating on the surface of the structured packing has partially fallen off. The optical microscope scanning results of solid impurities in the working fluid are as follows Figure 3 As shown, it also shows that the unstable structure of the surface copper oxide coating has fallen off. The ICP measurement results are shown in Table 1. The ICP measurement results show that the solid impurities in the working fluid are mainly copper compounds. The SEM image of the surface coating after flushing is shown in Figure 4 As shown in the figure, it can be found that there is no obvious change in the surface coating of the structured packing before and after a cycle of scouring, indicating that the copper oxide coating has good water scouring resistance stability. The hydrophilicity test of the surface coating after scouring is shown in the figure. Figure 5 As shown in the figure, the contact angle of the coating after flushing is 0°, and the surface flushing process has no effect on the hydrophilicity of the coating. The structured packing after flushing was used in the heavy water distillation process for separation performance test. The test results are shown in Table 2. The concentration ratio (heavy water content) and NTSM (equivalent theoretical plates per meter) did not change significantly, indicating that the structured packing still maintained good separation performance after flushing.

[0072] Table 1 ICP test results of CY700 wire mesh corrugated packing flushing working fluid

[0073]

[0074] Table 2 shows the test results of separation performance of CY700 wire mesh corrugated packing

[0075]

[0076] Example 2

[0077] The same durability test equipment as in Example 1 was used.

[0078] Durability test of CY800 wire mesh corrugated packing (copper purity of structured packing before coating modification is 99wt%, with copper oxide coating on the surface):

[0079] (1) Soak the CY800 wire mesh corrugated packing with copper hydroxide coating in deionized water at a temperature of 30° C. for about 30 min, and blow dry with nitrogen for later use;

[0080] (2) The wetted structured packing treated in step (1) was placed in a durability test distillation tower at 40°C, with a conductivity of 0.5 μS·cm-1 Deionized water is used for flushing, and the water flow rate is controlled to be 4m 3 ·h -1 , control the heating power of the heat exchanger to 35kW. When the system is stable, the pressure is 0.1MPa, the water storage capacity of the first liquid storage tank is maintained at 35%, deionized water is flushed for 10 hours, and the heating is turned off;

[0081] (3) After the temperature of the tower bottom drops to room temperature, repeat steps (2) and (3) 12 times;

[0082] (4) The optical image of the working fluid of the CY800 wire mesh corrugated packing after treatment is as follows Figure 6 As shown in the figure, it shows that the copper hydroxide coating on the surface of the structured packing has partially fallen off, but no obvious large-area flake shedding is observed. The optical microscope scanning results of solid impurities in the working solution are shown in the figure. Figure 7 As shown, it also shows that the unstable structure of the copper hydroxide coating has slightly fallen off. The ICP measurement results are shown in Table 3. The ICP measurement results are shown in Table 3. The ICP measurement results show that the solid impurities in the working fluid are mainly copper compounds. The SEM image of the surface coating after flushing is shown in Figure 8 As shown in the figure, it can be found that the microscopic morphology of the surface coating of the structured packing did not change significantly before and after a cycle of scouring, indicating that the copper hydroxide coating has good water scouring resistance stability. Fig. 9 As shown, the contact angle of the coating after flushing is 0°, and the surface flushing process has no effect on the hydrophilicity of the coating. The structured packing after flushing was used in the heavy water distillation process for separation performance test. The test results are shown in Table 4. The concentration ratio (heavy water content) and NTSM (equivalent theoretical plates per meter) did not change significantly, indicating that the structured packing still maintained good separation performance after flushing.

[0083] Table 3 ICP test results of CY800 wire mesh corrugated packing flushing working fluid

[0084]

[0085] Table 4 shows the test results of separation performance of CY800 wire mesh corrugated packing

[0086]

[0087] The present invention is described above by way of example. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be made by those skilled in the art without inventive effort falls within the protection scope of the present invention.

Claims

1. A durability test device for super hydrophilic structured packing coating, include: The cylindrical tower has a layered grid inside, with 2 to 6 layers, a logistics inlet at the top and a logistics outlet at the bottom, and filters are set at the logistics inlet and the logistics outlet; A first temperature measuring instrument is arranged at the top of the cylindrical tower; A first pressure measuring instrument is arranged at the top of the cylindrical tower; a second temperature measuring instrument, disposed in the cylindrical tower; a second pressure measuring instrument disposed in the cylindrical tower; A third temperature control instrument is arranged on the kettle of the cylindrical tower; Liquid level control instrument, set in the cylindrical tower kettle; A first liquid storage tank, wherein the bottom of the first liquid storage tank is provided with an outlet, and the outlet is connected to the logistics inlet at the top of the cylindrical tower; A second liquid storage tank, wherein the bottom of the second liquid storage tank is provided with an inlet, and the inlet is connected to the logistics outlet at the bottom of the cylindrical tower; a vacuum pump, disposed between the first liquid storage tank and the cylindrical tower; A heat exchanger is provided between the vacuum pump and the cylindrical tower.

2. The durability testing device according to claim 1, Features: The diameter of the cylindrical tower is 5 to 400 mm and the height is 400 to 3000 mm.

3. A durability testing method for a super-hydrophilic structured packing coating, preferably using the durability testing equipment described in claim 1 or 2, The following steps are involved: (1) Soak the structured packing in water; (2) placing the soaked structured packing on the layered grid of the durability test equipment, and after the system is stable, continue the flushing process with the flushing liquid and stop heating; (3) After the temperature of the cylindrical tower drops to room temperature, repeat step (2); (4) After flushing, the structured packing is washed, dried, characterized, and tested for performance.

4. The durability testing method of the super hydrophilic structured packing coating according to claim 3, Features: The surface of the structured packing has a specific coating, and the specific coating is a copper oxide or copper hydroxide coating; The structured packing is at least one of a wire mesh corrugated packing, a perforated plate corrugated packing, a perforated plate corrugated packing, and a plate mesh corrugated packing; The copper purity of the structured filler before coating modification is 95-99.99wt%.

5. The durability testing method of the super hydrophilic structured packing coating according to claim 3, Features: In step (1), the soaking time is 10 to 30 minutes and the soaking temperature is 5 to 70°C.

6. The durability testing method of the super hydrophilic structured packing coating according to claim 3, Features In step (2): The flushing fluid is deionized water; The conductivity of deionized water is 0.1~1.0μS·cm -1 ; Flushing fluid flow rate is 2~5m 3 ·h -1 ; The temperature of the flushing liquid is 5-70°C.

7. The durability testing method of the super hydrophilic structured packing coating according to claim 3, Features In step (2): After the system is stable, the pressure in the cylindrical tower is 0.070-0.100 MPa, and the temperature of the cylindrical tower is 5-70°C; The flushing time is 1 to 12 hours.

8. The durability testing method of the super hydrophilic structured packing coating according to claim 3, Features In step (2): The water storage capacity of the first liquid storage tank is maintained at 20-60% of its total volume.

9. The durability testing method of the super hydrophilic structured packing coating according to claim 3, Features In step (3): Repeat step (2) 5 to 150 times.

10. The durability testing method of the super-hydrophilic structured packing coating according to claim 3, Features: In step (4), the performance test includes observing solid impurities in the obtained working fluid, testing the copper ion content in the structured filler and the obtained working fluid, the water contact angle of the filler after durability testing, and the microscopic morphology of the coating.

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