A receiving electrode for active demisting and water saving and a preparation method thereof

Abstract

The present invention provides a receiving electrode for active demisting and water saving, comprising an electrode frame; a plurality of receiving electrode plates arranged vertically and in parallel are fixedly connected to the electrode frame at equal intervals; and a strengthening coating is provided on the outer surface of the receiving electrode plate. The present invention also provides a method for preparing the receiving electrode for active demisting and water saving, wherein the method for preparing the receiving electrode plate comprises: substrate pretreatment, intermediate layer treatment, outer coating agent preparation, and outer coating spraying. The receiving electrode for active demisting and water saving of the present invention effectively reduces airflow resistance, increases the contact area between the electrode and the mist, and improves the water collection efficiency of the active demisting and water saving device; reduces the friction between water droplets on its surface and the receiving electrode plate; the strengthening coating provided on the outer surface of the receiving electrode plate, the substrate-intermediate layer-outer coating of the receiving electrode plate are tightly combined, can resist the influence of adverse working conditions such as acid and alkali, and can effectively adapt to the working environment of high temperature, high humidity, and corona electric field.

Description

Technical Field

[0001] The invention relates to the field of electrostatic demisting, and in particular to a receiving electrode for active demisting and water saving and a preparation method thereof. Background Art

[0002] As a water cooling technology, wet cooling towers are widely used in the power, petrochemical, chemical and other industries. During the operation of the cooling tower, the circulating water in the tower is in direct contact with the air for heat and mass transfer. During the heat and mass transfer process, evaporation loss, wind loss and sewage loss of the circulating water will occur, resulting in a large waste of water resources, which is not conducive to the recycling of water resources. During the operation of the wet cooling tower, after the cold air exchanges heat with the water inside the cooling tower, it forms saturated hot and humid air with its evaporated air. Under certain climatic conditions, the hot and humid air is easily cooled and condensed by the cold air outside, forming a large amount of white mist containing a large number of tiny liquid particle groups, causing evaporation losses. At the same time, due to the low height of the mechanical ventilation cooling tower, the drifting of a large amount of white mist not only makes the road around the cooling tower slippery, affecting the normal safety inspection of the staff, but also affects the visibility of the surrounding residential areas and traffic roads, and has an adverse effect on the urban landscape. Therefore, it is of great significance to eliminate the white mist in the cooling tower and recycle and reuse the water in the white mist to reduce evaporation losses.

[0003] In recent years, the technology of using electrostatic demisting means for cooling tower demisting and water saving has been disclosed. It forms an electric field in the flow channel of water-containing mist by means of corona discharge (cathode), charges the small droplets in the water-containing mist, and makes the small droplets continuously agglomerate and move toward the anode, and finally be captured and collected by the anode. However, the inventor has found through research that the electrostatic demisting and water-saving device using large-area flat-plate electrodes has a large friction between the droplets and the electrode plate during operation, and the droplets have the problem of wall hanging during the dripping process, which is not conducive to the dripping and effective collection of droplets, and affects the water collection efficiency of the device.

[0004] After further research, the inventors found that when the currently available enhanced hydrophobic materials are used in active demisting and water-saving devices, the enhanced hydrophobic materials on the electrode surface are not ideal in durability during long-term operation in a high-temperature and high-humidity corona electric field environment, and the degree of bonding between the coating and the electrode will gradually decrease; at the same time, since a certain degree of acidic or alkaline components may remain in the water mist processed by the device, its coating cannot effectively resist long-term corrosion in a high-temperature and high-humidity corona electric field environment, resulting in unsatisfactory long-term stability of the device.

[0005] Chinese patent CN108072284A discloses a wet cooling tower demisting water collecting device, which is provided with a hydrophobic coating on the inner wall of the cyclone water collecting device of the wet cooling tower demisting, and the coating is a super-hydrophobic nano-controlled self-polymerizing coating coating containing silicon-fluorine functional groups. However, the defect of this patent is that the hydrophobic coating used in the electrostatic demisting water-saving device is used, and the durability and corrosion resistance of the coating are not ideal under the high temperature and high humidity corona electric field environment, and it cannot meet the requirements of long-term stable operation of the device; at the same time, the silicon-fluorine material used in it is harmful to the environment and human body to a certain extent, and it is not suitable for large-scale application. Summary of the invention

[0006] In order to solve the technical problems existing in the prior art, the present invention provides a receiving electrode for active demisting and water saving and a preparation method thereof to achieve the following invention objectives:

[0007] (1) Overcoming the problem that the existing flat plate electrodes used to capture droplets in electrostatic demisting are not conducive to the droplet falling and effective collection, thus affecting the water collection efficiency of the device;

[0008] (2) The flat electrode provided with the strengthening coating can effectively adapt to the high temperature and high humidity corona electric field environment, and has good durability and corrosion resistance during long-term operation.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0010] A receiving electrode for active demisting and water saving, comprising an electrode frame;

[0011] A plurality of vertically parallel receiving electrode plates are fixedly connected to the electrode frame in parallel and at equal distances;

[0012] The outer surface of the receiving electrode plate is provided with a strengthening coating.

[0013] The electrode frame is also fixedly connected with a liquid guiding cavity arranged in the same shape as the guide surface, and the liquid guiding cavity is used to collect the liquid dripping on the receiving electrode plate;

[0014] The liquid-conducting cavity comprises a shell with an inverted triangle cross section. A top hole is provided on the top surface of the liquid-conducting cavity, and the lower end of the receiving electrode plate is located in the top hole.

[0015] Furthermore, a plurality of the liquid guiding cavities are also commonly connected to an inclined water collecting channel on one side of the lower end portion, and the water collecting channel can collect and guide the liquid in each liquid guiding cavity to a predetermined position.

[0016] Furthermore, the preparation method of the receiving electrode plate includes: substrate pretreatment, intermediate layer treatment, outer coating agent preparation, and outer coating spraying.

[0017] Further, the substrate is pretreated, and a rectangular plate is selected as the receiving electrode plate substrate. The substrate is first ultrasonically cleaned with deionized water, and dried for 0.5-1h under hot air conditions of 60-80°C with a wind speed of 3-5m / s; the substrate is then ultrasonically cleaned with acetone, and dried at 70-80°C for 2-3h;

[0018] Preferably, the receiving electrode plate substrate is made of one of the following materials: aluminum and aluminum alloy plate, stainless steel plate, and PP plastic plate.

[0019] Furthermore, the intermediate layer treatment adopts a radio frequency magnetron sputtering process, in a mixed atmosphere of oxygen and argon, firstly depositing a NiO layer on the surface of the substrate obtained in the substrate pretreatment step, and then continuing to deposit a Ni layer on the NiO layer in an argon atmosphere;

[0020] The thickness of the NiO layer is 500-600 nm, and the total thickness of the intermediate layer is 1000-800 nm.

[0021] Preferably, the RF magnetron sputtering process has a sputtering power of 650-700W;

[0022] The volume ratio of oxygen to argon is 1:6-8;

[0023] The negative deviation of the pulse is -80V~-90V.

[0024] Furthermore, the outer coating agent is prepared by modifying and mixing multi-walled carbon nanotubes;

[0025] The multi-walled carbon nanotubes are modified by using a predetermined amount of a mixed solution of acetonitrile, azobisisoheptanenitrile and ethanol to modify the multi-walled carbon nanotubes.

[0026] Preferably, the weight ratio of the multi-walled carbon nanotubes: acetonitrile: azobisisoheptanenitrile: ethanol is 1-1.5:3-5:2-3:20-30.

[0027] Furthermore, in the mixed preparation, the multi-walled carbon nanotubes obtained in the multi-walled carbon nanotube modification step are placed in a predetermined amount of N-methylpyrrolidone and uniformly dispersed by ultrasonication to obtain Agent A;

[0028] The solvent-based polyurethane resin is placed in a predetermined amount of N-methylpyrrolidone and uniformly dispersed by ultrasonication to obtain Agent B;

[0029] Then, the agent A and the agent B are mixed evenly to prepare an outer coating agent.

[0030] Furthermore, the weight ratio of the multi-walled carbon nanotubes to N-methylpyrrolidone is 1:65-70;

[0031] The weight ratio of the solvent-based polyurethane resin to N-methylpyrrolidone is 1:25-30.

[0032] The active demisting and water-saving receiving electrode of the present invention reduces the airflow resistance through the vertically and inclined receiving electrode plates, ensures the smoothness of the airflow, increases the contact area with the mist, improves the water collection efficiency of the active demisting and water-saving device, and realizes directional guidance of the condensed liquid through the inclined guide surface of the receiving electrode plates.

[0033] At the same time, due to the reinforced coating on the outer surface of the receiving electrode plate, the friction between the water droplets on its surface and the receiving electrode plate is effectively reduced, and the phenomenon of droplets hanging on the wall between the receiving electrode plates is overcome. In addition, a liquid guide cavity is set below the guide surface, and a top hole is opened on the liquid guide cavity, so that the droplets on the receiving electrode plate are effectively collected into the liquid guide cavity. A water collection channel is set at the lower end of the liquid guide cavity, and a water collection hole is opened through the water collection channel, so that the liquid in the liquid guide cavity enters the water collection channel from the side hole, and the water in several liquid guide cavities is collected in the water collection channel; and the collected water is drained to a predetermined location through the water collection channel, such as a cooling tower pool or other equipment.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The active demisting and water-saving receiving electrode of the present invention effectively reduces the airflow resistance by setting a specific vertical and inclined receiving electrode plate. While ensuring the smooth passage of water-containing mist through the corona electric field, it effectively increases the contact area between the electrode and the mist, effectively improves the water collection efficiency of the active demisting and water-saving device, and realizes directional diversion of the liquid on the receiving electrode plate.

[0036] (2) The active demisting and water-saving receiving electrode of the present invention effectively reduces the friction between the water droplets on the surface and the receiving electrode plate by providing a specific strengthening coating on the outer surface of the receiving electrode plate, and effectively eliminates the phenomenon of droplets hanging on the side wall of the receiving electrode plate.

[0037] (3) The active demisting and water-saving receiving electrode of the present invention has a specific strengthening coating arranged on the outer surface of the receiving electrode plate, and the substrate, intermediate layer and outer coating of the receiving electrode plate are tightly bonded, which can effectively resist the influence of adverse working conditions such as acid and alkali, and can effectively adapt to the high temperature, high humidity and corona electric field environment that the device faces for a long time; during the long-term operation of the active demisting and water-saving device, the bonding between the outer surface coating of the receiving electrode plate and the substrate is firm; the durability and long-term stability of the active demisting and water-saving device can meet the requirements of long-term operation.

[0038] (4) The receiving electrode for active demisting and water-saving of the present invention has a hydrophobic angle of 155-161° on the outer surface of the receiving electrode plate and a rolling angle of 2.6-3.1°, which can make the droplets condensed on the surface drip quickly and be effectively collected, further improving the water collection capacity of the active demisting and water-saving device.

[0039] (5) The active demisting and water-saving receiving electrode of the present invention has a reinforced coating disposed on the outer surface of the receiving electrode plate. The coating adhesion is measured according to the national standard GB / T 9286-1998 "Scratching test for paint and varnish films". The coating cutting edge is relatively smooth, there is no obvious coating shedding at the intersection, and the affected damaged area at the intersection is less than 2.1%, and the coating adhesion is level 1.

[0040] (6) The active demisting and water-saving receiving electrode of the present invention has a reinforced coating on the outer surface of the receiving electrode plate, which is subjected to a corrosion resistance test: after being kept in an acidic environment of pH = 1 for 30 days, the hydrophobic angle of the outer surface of the receiving electrode plate is 144-151°; after being kept in an alkaline environment of pH = 13 for 30 days, the hydrophobic angle of the outer surface of the receiving electrode plate is 141-148°; its durability and long-term stability are effectively guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0042] Figure 1 A top view of the receiving electrode for active demisting and water saving of the present invention;

[0043] Figure 2 for Figure 1 A-direction view;

[0044] Figure 3 It is a structural schematic diagram of the liquid guiding cavity of the present invention.

[0045] In the figure: 1-electrode frame; 2-receiving electrode plate; 3-liquid guiding cavity; 4-side hole; 5-water collecting channel; 6-water collecting hole; 7-top hole; 8-connecting block. DETAILED DESCRIPTION

[0046] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described.

[0047] Example 1

[0048] like Figure 1As shown, the active demisting and water-saving receiving electrode of this embodiment includes an electrode frame 1, on which a plurality of vertically parallel receiving electrode plates 2 are fixedly connected in parallel and at equal intervals, and the outer surface of the receiving electrode plate 2 is provided with a strengthening coating.

[0049] like Figure 2 As shown, the receiving electrode plate 2 is also arranged to be inclined vertically, and a guide surface is formed by its inclined lower end. A liquid guide cavity 3 arranged in the same shape as the guide surface is also fixedly connected to the electrode frame 1, and the liquid guide cavity 3 is used to collect liquid dripping from the receiving electrode plate 2.

[0050] A plurality of liquid guiding cavities 3 are also commonly connected to an inclined water collecting channel 5 at one side of the lower end portion, and the water collecting channel 5 can collect and guide the liquid in each liquid guiding cavity 3 to a predetermined position.

[0051] Further, such as Figure 3 As shown, the liquid-conducting cavity 3 includes a shell having an inverted triangular cross section, a top hole 7 is provided on the top surface of the liquid-conducting cavity 3 , and the lower end of the receiving electrode plate 2 is located in the top hole 7 .

[0052] Side holes 4 are formed on the lower end surfaces of the plurality of liquid guiding cavities 3 , and water collecting holes 6 located below the plurality of side holes 4 are formed on the top surface of the water collecting channel 5 .

[0053] Furthermore, connecting blocks 8 connected to the opposite inner walls of the liquid guiding cavity 3 are respectively fixedly connected to the opposite side walls of the receiving electrode plate 2 located in the liquid guiding cavity 3 .

[0054] The method for preparing the receiving electrode plate 2 includes: substrate pretreatment, intermediate layer treatment, outer coating agent preparation, and outer coating spraying.

[0055] The substrate is pretreated by selecting a rectangular plate as the receiving electrode plate substrate, and the substrate is completely immersed in 15 times the volume of deionized water, and ultrasonically cleaned for 20 minutes; then dried with 70°C hot air at a wind speed of 5m / s for 1 hour; then the substrate is completely immersed in 8 times acetone, ultrasonically cleaned for 30 minutes, and dried at 80°C for 3 hours for use.

[0056] The acetone is industrial acetone with a purity of 99.5%.

[0057] The ultrasonic cleaning has an ultrasonic frequency of 100 KHz.

[0058] The substrate is a PP plastic plate.

[0059] For the intermediate layer treatment, the substrate prepared in the substrate pretreatment step is placed in a radio frequency magnetron sputtering device, and in an environment where a mixed gas of oxygen and argon is continuously introduced, the vacuum degree is maintained at 0.1 Pa, and a radio frequency power supply is used to sputter the Ni target. When the deposition thickness of Ni on the outer surface of the substrate reaches 550nm, the oxygen supply is turned off, and in an environment where oxygen is continuously introduced, the vacuum degree is maintained at 0.07 Pa, and the radio frequency power supply is continued to sputter the Ni target. When the total thickness of the intermediate layer on the outer surface of the substrate reaches 800nm, the intermediate layer treatment is completed.

[0060] In the magnetron sputtering process of the intermediate layer treatment, the sputtering power is 650W, the volume ratio of the introduced oxygen:argon gas is 1:6, and the pulse negative deviation is -80V~-90V.

[0061] The preparation of the outer coating agent includes modification and mixing of multi-walled carbon nanotubes.

[0062] The multi-walled carbon nanotubes are modified by placing the multi-walled carbon nanotubes in 5 times the volume of nitric acid, ultrasonically dispersing for 15 minutes, stirring at 300RPM for 2 hours, filtering out, washing with 3 times the volume of deionized water, and then washing with 5 times the volume of anhydrous ethanol and drying; then the multi-walled carbon nanotubes are mixed with a predetermined number of acetonitrile, azobisisoheptanenitrile, and ethanol, ultrasonically dispersing for 10 minutes, heating to 60°C under stirring at 30RPM, and keeping warm for 5 hours to filter out the multi-walled carbon nanotubes; washing the multi-walled carbon nanotubes with 4 times the volume of anhydrous ethanol, and drying for use.

[0063] The weight ratio of the multi-walled carbon nanotubes: acetonitrile: azobisisoheptanenitrile: ethanol is 1:3:3:20.

[0064] The mixed preparation comprises placing the modified multi-walled carbon nanotubes into a predetermined amount of N-methylpyrrolidone, and uniformly dispersing them by ultrasonication to obtain agent A; placing the solvent-based polyurethane resin into a predetermined amount of N-methylpyrrolidone, and uniformly dispersing them by ultrasonication to obtain agent B; and then mixing agent A and agent B, and stirring at 300RPM for 1.5 hours to obtain an outer coating agent.

[0065] The weight ratio of the multi-walled carbon nanotubes to N-methylpyrrolidone is 1:70.

[0066] The weight ratio of the solvent-based polyurethane resin to N-methylpyrrolidone is 1:25.

[0067] The solvent-based polyurethane resin has a solid content of 35%.

[0068] The outer coating spraying is to spray the outer coating agent onto the substrate obtained in the intermediate layer treatment step, and then let it stand for 8 hours at 80° C. to obtain the receiving electrode plate.

[0069] The spraying was performed at a distance of 15 cm and a pressure of 4 KPa.

[0070] The active demisting and water-saving receiving electrode of this embodiment reduces the airflow resistance through the vertically and inclined receiving electrode plate 2, ensures the smoothness of the airflow, increases the contact area with the mist, improves the water collection efficiency of the active demisting and water-saving device, and realizes directional diversion of the condensed liquid through the inclined guide surface of the receiving electrode plate 2.

[0071] At the same time, due to the reinforced coating on the outer surface of the receiving electrode plate 2, the friction between the water droplets on its surface and the receiving electrode plate is effectively reduced, and the phenomenon of droplets hanging on the wall between the receiving electrode plates is overcome. In addition, a liquid guide cavity 3 is set below the guide surface of the receiving electrode 2, and a top hole 7 is opened on the liquid guide cavity 3, so that the droplets on the receiving electrode plate 2 are effectively collected into the liquid guide cavity 3; and a water collection channel 5 is set at the lower end of the liquid guide cavity 3, and a water collection hole 6 is opened through the water collection channel 5, so that the liquid in the liquid guide cavity 3 enters the water collection channel 5 from the side hole 4, and the water in several liquid guide cavities 3 is collected together in the water collection channel 5; and the collected water is drained to a predetermined position through the water collection channel 5, such as a cooling tower pool or other equipment, so that the liquid is effectively collected.

[0072] In this embodiment, the hydrophobicity of the outer surface of the receiving electrode plate was tested, and the hydrophobic angle was 161° and the rolling angle was 2.6°.

[0073] In this embodiment, the adhesion of the hydrophobic coating on the outer surface of the receiving electrode plate was tested, and the coating adhesion was measured according to the national standard GB / T 9286-1998 "Scratching test for paint and varnish film". After the coating test, the cutting edge was relatively smooth, there was no obvious shedding at the intersection, the affected damage area at the intersection was 1.7%, and the coating adhesion was level 1.

[0074] In this embodiment, the corrosion resistance of the outer surface of the receiving electrode plate was tested: 1) the receiving electrode plate sample sprayed with the strengthening coating was completely immersed in 0.1 mol / L HCl, and the hydrophobic angle of the outer surface was 151° after 30 days; 2) the receiving electrode plate sample sprayed with the strengthening coating was completely immersed in 0.1 mol / L NaOH, and the hydrophobic angle of the outer surface was 146° after 30 days.

[0075] Example 2

[0076] like Figure 1 As shown, the active demisting and water-saving receiving electrode of this embodiment includes an electrode frame 1, on which a plurality of vertically parallel receiving electrode plates 2 are fixedly connected in parallel and at equal intervals, and the outer surface of the receiving electrode plate 2 is provided with a strengthening coating.

[0077] like Figure 2As shown, the receiving electrode plate 2 is also arranged to be inclined vertically, and a guide surface is formed by its inclined lower end. A liquid guide cavity 3 arranged in the same shape as the guide surface is also fixedly connected to the electrode frame 1, and the liquid guide cavity 3 is used to collect liquid dripping from the receiving electrode plate 2.

[0078] A plurality of liquid guiding cavities 3 are also commonly connected to an inclined water collecting channel 5 at one side of the lower end portion, and the water collecting channel 5 can collect and guide the liquid in each liquid guiding cavity 3 to a predetermined position.

[0079] Further, such as Figure 3 As shown, the liquid-conducting cavity 3 includes a shell having an inverted triangular cross section, a top hole 7 is provided on the top surface of the liquid-conducting cavity 3 , and the lower end of the receiving electrode plate 2 is located in the top hole 7 .

[0080] Side holes 4 are formed on the lower end surfaces of the plurality of liquid guiding cavities 3 , and water collecting holes 6 located below the plurality of side holes 4 are formed on the top surface of the water collecting channel 5 .

[0081] Furthermore, connecting blocks 8 connected to the opposite inner walls of the liquid guiding cavity 3 are respectively fixedly connected to the opposite side walls of the receiving electrode plate 2 located in the liquid guiding cavity 3 .

[0082] The method for preparing the receiving electrode plate 2 includes: substrate pretreatment, intermediate layer treatment, outer coating agent preparation, and outer coating spraying.

[0083] The substrate is pretreated by selecting a rectangular plate as the receiving electrode plate substrate, and the substrate is completely immersed in 10 times the volume of deionized water, and ultrasonically cleaned for 10 minutes; then dried for 0.5 hours using 60°C hot air with a wind speed of 3m / s; then the substrate is completely immersed in 5 times the volume of acetone, ultrasonically cleaned for 20 minutes, and dried at 70°C for 2 hours for use.

[0084] The acetone is industrial acetone with a purity of 98%.

[0085] The ultrasonic cleaning has an ultrasonic frequency of 80 KHz.

[0086] The substrate is a stainless steel plate.

[0087] For the intermediate layer treatment, the substrate prepared in the substrate pretreatment step is placed in a radio frequency magnetron sputtering device, and in an environment where a mixed gas of oxygen and argon is continuously introduced, the vacuum degree is maintained at 0.08 Pa, and a radio frequency power supply is used to sputter the Ni target. When the deposition thickness of Ni on the outer surface of the substrate reaches 500nm, the oxygen supply is turned off, and in an environment where oxygen is continuously introduced, the vacuum degree is maintained at 0.06 Pa, and the radio frequency power supply is continued to sputter the Ni target. When the total thickness of the intermediate layer on the outer surface of the substrate reaches 1000nm, the intermediate layer treatment is completed.

[0088] In the magnetron sputtering process of the intermediate layer treatment, the sputtering power is 650W, the volume ratio of the introduced oxygen:argon gas is 1:6, and the pulse negative deviation is -80V~-90V.

[0089] The preparation of the outer coating agent includes modification and mixing of multi-walled carbon nanotubes.

[0090] The multi-walled carbon nanotubes are modified by placing the multi-walled carbon nanotubes in 3 volumes of nitric acid, ultrasonically dispersing for 10 minutes, stirring at 200RPM for 1 hour, filtering out, washing with 2 volumes of deionized water, and then washing with 4 volumes of anhydrous ethanol and drying; then mixing the multi-walled carbon nanotubes with predetermined portions of acetonitrile, azobisisoheptanenitrile, and ethanol, ultrasonically dispersing for 8 minutes, heating to 60°C under stirring at 20RPM, and filtering out the multi-walled carbon nanotubes after keeping warm for 4 hours; washing the multi-walled carbon nanotubes with 3 volumes of anhydrous ethanol, and drying for use.

[0091] The weight ratio of the multi-walled carbon nanotubes: acetonitrile: azobisisoheptanenitrile: ethanol is 1:3:3:20.

[0092] The mixed preparation comprises placing the modified multi-walled carbon nanotubes into a predetermined amount of N-methylpyrrolidone, and uniformly dispersing them by ultrasonication to obtain agent A; placing a solvent-based polyurethane resin into a predetermined amount of N-methylpyrrolidone, and uniformly dispersing them by ultrasonication to obtain agent B; and then mixing agent A and agent B, and stirring them at 200RPM for 1 hour to obtain an outer coating agent.

[0093] The weight ratio of the multi-walled carbon nanotubes to N-methylpyrrolidone is 1:65.

[0094] The weight ratio of the solvent-based polyurethane resin to N-methylpyrrolidone is 1:25.

[0095] The solvent-based polyurethane resin has a solid content of 30%.

[0096] The outer coating spraying step comprises spraying the outer coating agent onto the substrate obtained in the intermediate layer treatment step, and then standing the substrate at 80° C. for 10 hours to obtain the receiving electrode plate.

[0097] The spraying distance is 8 cm and the spraying pressure is 3 KPa.

[0098] In this embodiment, the hydrophobicity of the outer surface of the receiving electrode plate was tested, and the hydrophobic angle was 155° and the rolling angle was 3.1°.

[0099] In this embodiment, the adhesion of the hydrophobic coating on the outer surface of the receiving electrode plate was tested, and the coating adhesion was measured according to the national standard GB / T 9286-1998 "Scratching test for paint and varnish film". After the coating test, the cutting edge was relatively smooth, there was no obvious shedding at the intersection, the affected damage area at the intersection was 2.0%, and the coating adhesion was level 1.

[0100] In this embodiment, the corrosion resistance of the outer surface of the receiving electrode plate is tested: 1) the receiving electrode plate sample sprayed with the strengthening coating is completely immersed in 0.1 mol / L HCl. After 30 days, the hydrophobic angle of the outer surface is 144°; 2) the receiving electrode plate sample sprayed with the strengthening coating is completely immersed in 0.1 mol / L NaOH. After 30 days, the hydrophobic angle of the outer surface is 141°.

[0101] Example 3

[0102] like Figure 1 As shown, the active demisting and water-saving receiving electrode of this embodiment includes an electrode frame 1, on which a plurality of vertically parallel receiving electrode plates 2 are fixedly connected in parallel and at equal intervals, and the outer surface of the receiving electrode plate 2 is provided with a strengthening coating.

[0103] like Figure 2 As shown, the receiving electrode plate 2 is also arranged to be inclined vertically, and a guide surface is formed by its inclined lower end. A liquid guide cavity 3 arranged in the same shape as the guide surface is also fixedly connected to the electrode frame 1, and the liquid guide cavity 3 is used to collect liquid dripping from the receiving electrode plate 2.

[0104] A plurality of liquid guiding cavities 3 are also commonly connected to an inclined water collecting channel 5 at one side of the lower end portion, and the water collecting channel 5 can collect and guide the liquid in each liquid guiding cavity 3 to a predetermined position.

[0105] Further, such as Figure 3 As shown, the liquid-conducting cavity 3 includes a shell having an inverted triangular cross section, a top hole 7 is provided on the top surface of the liquid-conducting cavity 3 , and the lower end of the receiving electrode plate 2 is located in the top hole 7 .

[0106] Side holes 4 are formed on the lower end surfaces of the plurality of liquid guiding cavities 3 , and water collecting holes 6 located below the plurality of side holes 4 are formed on the top surface of the water collecting channel 5 .

[0107] Furthermore, connecting blocks 8 connected to the opposite inner walls of the liquid guiding cavity 3 are respectively fixedly connected to the opposite side walls of the receiving electrode plate 2 located in the liquid guiding cavity 3 .

[0108] The method for preparing the receiving electrode plate 2 includes: substrate pretreatment, intermediate layer treatment, outer coating agent preparation, and outer coating spraying.

[0109] The substrate is pretreated by selecting a rectangular plate as the receiving electrode plate substrate, and the substrate is completely immersed in 15 times the volume of deionized water, and ultrasonically cleaned for 20 minutes; then dried with 80°C hot air at a wind speed of 4m / s for 1 hour; then the substrate is completely immersed in 10 times the volume of acetone, ultrasonically cleaned for 30 minutes, and dried at 80°C for 3 hours for use.

[0110] The acetone is industrial acetone with a purity of 99.5%.

[0111] The ultrasonic cleaning has an ultrasonic frequency of 80 KHz.

[0112] The substrate is a PP plastic plate.

[0113] For the intermediate layer treatment, the substrate obtained in the substrate pretreatment step is placed in a radio frequency magnetron sputtering device, and in an environment where a mixed gas of oxygen and argon is continuously introduced, the vacuum degree is maintained at 0.1 Pa, and a radio frequency power supply is used to sputter the Ni target. When the deposition thickness of Ni on the outer surface of the substrate reaches 600nm, the oxygen supply is turned off, and in an environment where oxygen is continuously introduced, the vacuum degree is maintained at 0.07pa, and the radio frequency power supply is continued to sputter the Ni target. When the total thickness of the intermediate layer on the outer surface of the substrate reaches 800nm, the intermediate layer treatment is completed.

[0114] In the magnetron sputtering process of the intermediate layer treatment, the sputtering power is 700W, the volume ratio of the introduced oxygen:argon gas is 1:8, and the pulse negative deviation is -80V~-90V.

[0115] The preparation of the outer coating agent includes modification and mixing of multi-walled carbon nanotubes.

[0116] The multi-walled carbon nanotubes are modified by placing the multi-walled carbon nanotubes in 5 times the volume of nitric acid, ultrasonically dispersing for 20 minutes, stirring at 300RPM for 2 hours, filtering out, washing with 3 times the volume of deionized water, and then washing with 5 times the volume of anhydrous ethanol and drying; then mixing the multi-walled carbon nanotubes with predetermined portions of acetonitrile, azobisisoheptanenitrile, and ethanol, ultrasonically dispersing for 10 minutes, heating to 60°C under stirring at 40RPM, and keeping the temperature for 5 hours to filter out the multi-walled carbon nanotubes; washing the multi-walled carbon nanotubes with 5 times the volume of anhydrous ethanol, and drying for use.

[0117] The weight ratio of the multi-walled carbon nanotubes: acetonitrile: azobisisoheptanenitrile: ethanol is 1.5: 5: 2: 20.

[0118] The mixed preparation comprises placing the modified multi-walled carbon nanotubes into a predetermined amount of N-methylpyrrolidone, and uniformly dispersing them by ultrasonication to obtain agent A; placing the solvent-based polyurethane resin into a predetermined amount of N-methylpyrrolidone, and uniformly dispersing them by ultrasonication to obtain agent B; and then mixing agent A and agent B, and stirring at 300RPM for 1.5 hours to obtain an outer coating agent.

[0119] The weight ratio of the multi-walled carbon nanotubes to N-methylpyrrolidone is 1:70.

[0120] The weight ratio of the solvent-based polyurethane resin to N-methylpyrrolidone is 1:30.

[0121] The solvent-based polyurethane resin has a solid content of 35%.

[0122] The outer coating spraying is to spray the outer coating agent onto the substrate obtained in the intermediate layer treatment step, and then let it stand for 8 hours at 80° C. to obtain the receiving electrode plate.

[0123] The spraying was performed at a distance of 15 cm and a pressure of 5 KPa.

[0124] The active demisting and water-saving receiving electrode of this embodiment reduces the airflow resistance through the vertically and inclined receiving electrode plate 2, ensures the smoothness of the airflow, increases the contact area with the mist, improves the water collection efficiency of the active demisting and water-saving device, and realizes directional diversion of the condensed liquid through the inclined guide surface of the receiving electrode plate 2.

[0125] In this embodiment, the hydrophobicity of the outer surface of the receiving electrode plate was tested, and the hydrophobic angle was 157° and the rolling angle was 2.8°.

[0126] In this embodiment, the adhesion of the hydrophobic coating on the outer surface of the receiving electrode plate was tested, and the coating adhesion was measured according to the national standard GB / T 9286-1998 "Scratching test for paint and varnish film". After the coating test, the cutting edge was relatively smooth, there was no obvious shedding at the intersection, the affected damage area at the intersection was 1.9%, and the coating adhesion was level 1.

[0127] The corrosion resistance test of the outer surface of the receiving electrode plate was carried out. 1) The receiving electrode plate sample sprayed with the strengthening coating was completely immersed in 0.1 mol / L HCl. After 30 days, the hydrophobic angle of the outer surface was 147°; 2) The receiving electrode plate sample sprayed with the strengthening coating was completely immersed in 0.1 mol / L NaOH. After 30 days, the hydrophobic angle of the outer surface was 148°.

[0128] Comparative Example 1

[0129] In this comparative example, the technical solution of Example 1 is adopted, except that the intermediate layer processing step is deleted.

[0130] In this comparative example, the hydrophobicity of the outer surface of the receiving electrode plate was tested, and the hydrophobic angle was 160° and the rolling angle was 2.6°.

[0131] The coating adhesion of the outer surface of the receiving electrode plate was measured according to the national standard GB / T 9286-1998 "Scratch test for paint and varnish films". The coating fell off at the intersection of the coating cuts and / or along the edges of the cuts. The affected cross-cut area was about 7.2% (greater than 5%), and the coating adhesion was level 2.

[0132] Unless otherwise specified, all percentages used in the present invention are by mass.

[0133] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a receiving electrode for active demisting and water saving, characterized in that: The active demisting and water-saving receiving electrode comprises an electrode frame (1); A plurality of receiving electrode plates (2) arranged vertically and in parallel are fixedly connected to the electrode frame (1) at equal intervals. The outer surface of the receiving electrode plate (2) is provided with a strengthening coating, and the strengthening coating is used to reduce the friction between the droplets on the outer surface of the receiving electrode plate and the receiving electrode plate; The method for preparing the receiving electrode plate (2) comprises: substrate pretreatment, intermediate layer treatment, outer coating agent preparation, and outer coating spraying; The substrate is pretreated by selecting a rectangular plate as the receiving electrode plate substrate. The substrate is first ultrasonically cleaned with deionized water and dried for 0.5-1h under hot air conditions of 60-80°C at a wind speed of 3-5m / s; the substrate is then ultrasonically cleaned with acetone and dried at 70-80°C for 2-3h; The receiving electrode plate substrate is made of one of the following materials: aluminum and aluminum alloy plate, stainless steel plate, PP plastic plate; The intermediate layer treatment adopts a radio frequency magnetron sputtering process, firstly depositing a NiO layer on the surface of the substrate prepared in the substrate pretreatment step in a mixed atmosphere of oxygen and argon; and then continuing to deposit a Ni layer on the NiO layer in an argon atmosphere; The outer coating agent preparation includes modification and mixing of multi-walled carbon nanotubes; The multi-walled carbon nanotube modification comprises modifying the multi-walled carbon nanotube using a predetermined amount of a mixture of acetonitrile, azobisisoheptanenitrile and ethanol; The mixed preparation comprises placing the multi-walled carbon nanotubes obtained in the multi-walled carbon nanotube modification step into a predetermined amount of N-methylpyrrolidone and uniformly dispersing the mixture by ultrasonication to obtain agent A; The solvent-based polyurethane resin is placed in a predetermined amount of N-methylpyrrolidone and uniformly dispersed by ultrasonication to obtain Agent B; Then, the agent A and the agent B are mixed evenly to prepare an outer coating agent; The outer coating is sprayed on the substrate obtained by the intermediate layer treatment to obtain the receiving electrode plate.

2. The method for preparing the receiving electrode for active demisting and water saving according to claim 1, characterized in that: In the active demisting and water-saving receiving electrode, the receiving electrode plate (2) is also arranged to be inclined vertically, and a guide surface is formed through its inclined lower end; a liquid guide cavity (3) arranged in the same shape as the guide surface is also fixedly connected to the electrode frame (1), and the liquid guide cavity (3) is used to collect liquid dripping from the receiving electrode plate (2); The liquid-conducting cavity (3) comprises a shell having an inverted triangular cross-section, a top hole (7) is provided on the top surface of the liquid-conducting cavity (3), and the lower end of the receiving electrode plate (2) is located in the top hole (7).

3. The method for preparing the receiving electrode for active demisting and water saving according to claim 2, characterized in that: A plurality of the liquid guiding cavities (3) are also commonly connected to an inclined water collecting channel (5) at one side of the lower end portion, and the water collecting channel (5) is capable of collecting and guiding the liquid in each of the liquid guiding cavities (3) to a predetermined position.

4. The method for preparing the receiving electrode for active demisting and water saving according to claim 1, characterized in that: The thickness of the NiO layer is 500-600 nm, and the total thickness of the intermediate layer is 800-1000 nm.

5. The method for preparing the receiving electrode for active demisting and water saving according to claim 1, characterized in that: The radio frequency magnetron sputtering process has a sputtering power of 650-700W; The volume ratio of oxygen to argon is 1:6-8; The pulse negative deviation is -90V to -80V.

6. The method for preparing the receiving electrode for active demisting and water saving according to claim 1, characterized in that: The weight ratio of the multi-walled carbon nanotubes: acetonitrile: azobisisoheptanenitrile: ethanol is 1-1.5: 3-5: 2-3: 20-30.

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