A multi-layer tubular anode device for efficient chlorine evolution and its preparation method

Abstract

A multi-layer tubular anode device for efficient chlorine evolution and its preparation method. The device includes a central anode. Outside the central anode tube, a titanium electrode tube is arranged from the inside outwards. Outside the titanium electrode tube, a cathode tube is arranged. At one end where the central anode tube exposes the titanium electrode tube, an anode connecting plate is arranged. Outside the cathode tube, a cathode connecting plate is arranged. The preparation method includes: S1. Selecting titanium materials for cutting; S2. Degreasing treatment; S3. Acid etching treatment; S4. Coating treatment; S5. Assembling. By using a multi-layer tubular titanium electrode tube, the surface of the titanium electrode tube presents an irregular porous shape, which can make the electrolysis of sodium chloride more uniform and complete. The central anode tube, the titanium electrode tube and the cathode tube all adopt a hollow design, which can save titanium materials. Introducing precious metal Pd to replace precious metal Ir in the coating solution configuration can greatly reduce costs, and has the characteristics of convenient operation, simple structure and cost saving.

Description

Technical Field

[0001] The present invention relates to the technical field of anode preparation, and particularly relates to a multi-layer tubular anode device for efficient chlorine evolution and a preparation method thereof. Background Art

[0002] The titanium anode, also known as the dimensionally stable anode, is composed of a metal matrix (with titanium metal as the matrix) and a surface active coating. Since its birth in 1968, the titanium anode has experienced more than 50 years of development. It has developed from being used in the chlor-alkali industry at the earliest to being widely used in fields such as chemical engineering, environmental protection, water electrolysis, water treatment, electro-metallurgy, electroplating, metal foil production, organic electrosynthesis, electrodialysis, and cathodic protection. As a very important branch of metal anodes, the titanium anode plays a huge role in economic development.

[0003] The noble metal coated titanium anode is formed by coating a noble metal oxide on a titanium substrate, and it has high catalytic activity and a long service life. However, with the rapid development of technology, the electrocatalytic activity of the electrode gradually fails to meet the market demand. Therefore, how to improve the electrocatalytic activity of electrolysis from the aspects of structure and coating ratio is one of the most urgent tasks in the current electrocatalysis field. Summary of the Invention

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a multi-layer tubular anode device for efficient chlorine evolution and a preparation method thereof. By using a multi-layer tubular titanium electrode, and except for the central anode tube and the cathode tube, the surfaces of the other titanium electrode tubes are irregularly porous, which can facilitate the free flow of sodium chloride solution in the entire generator, and the sodium chloride electrolysis is more uniform and complete. The central anode tube, the titanium electrode tube, and the cathode tube are all designed to be hollow, which can save titanium materials, reduce the mass and preparation cost of the generator. In the preparation of the noble metal coating solution, noble metal Pd is introduced to replace noble metal Ir, which can greatly reduce the cost, and has the characteristics of convenient operation, simple structure, and cost savings.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A multi-layer tubular anode device for efficient chlorine evolution includes a central anode tube. An outer layer of the central anode tube is sleeved with a titanium electrode tube, and an outer layer of the titanium electrode tube is sleeved with a cathode tube. One end of the central anode tube exposed from the titanium electrode tube is provided with an anode connection plate, and an outer layer of the cathode tube is provided with a cathode connection plate.

[0007] The titanium electrode tube is composed of multiple layers of hollow cylindrical titanium electrodes. On the surfaces of the hollow cylindrical titanium electrode tubes with different diameters in each layer, there are holes with different sizes and uneven distributions, and the holes are not connected to each other.

[0008] One end of the cathode tube and the titanium electrode tube is provided with a base, and one side of the base is provided with a first support plate. The other end of the cathode tube and the titanium electrode tube is configured with a sealing cover, and one side of the sealing cover is provided with a second support plate.

[0009] The sealing cover is provided with a first liquid inlet and a second liquid inlet. Both the first liquid inlet and the second liquid inlet communicate with the inner cavity of the titanium electrode tube. One end of the central anode tube close to the sealing cover is provided with a first liquid outlet, and one end of the central anode tube close to the base is provided with a second liquid outlet. The second liquid outlet is connected to the inner cavity of the titanium electrode tube. The first liquid inlet and the second liquid inlet are connected to the sodium chloride solution through pipelines, and the first liquid outlet is connected to the liquid storage bucket through a pipeline.

[0010] During the electrolysis process, the positions of the coatings on the central anode tube, the cathode tube and the titanium electrode tube can be changed according to actual needs, so as to be used as a reverse electrode or a non-reverse electrode; when used as a reverse electrode, there is a coating on the outer side of the central anode tube and no coating on the inner side. There are coatings on both the inner and outer sides of each layer of the titanium electrode tube, and there is a coating on the inner side of the cathode tube and no coating on the outer side; when used as a non-reverse electrode, there is a coating on the outer side of the central anode tube and no coating on the inner side. There is no coating on the inner side of each layer of the titanium electrode tube and there is a coating on the outer side, and there is no coating on both the inner and outer sides of the cathode tube.

[0011] The coating is coated with a noble metal coating solution. The noble metal coating solution is composed of a mixed solution of RuCl3·3H2O, tetrabutyl titanate, chloropalladic acid and n-butanol added with hydrochloric acid. The mass ratio of ruthenium, palladium and titanium is:

[0012] Ru:Pd:Ti = 2:(0.6 - 1.2):(4 - 8).

[0013] A preparation method of a multi-layer tubular anode device for efficient chlorine evolution includes the following steps:

[0014] S1. Select titanium materials and cut and form the selected titanium materials according to requirements;

[0015] S2. Degrease the titanium materials cut and formed in step S1;

[0016] S3. Acid-etch the titanium materials degreased in step S2;

[0017] S4. Coat the titanium materials acid-etched in step S3;

[0018] S5. Assemble the titanium materials coated in step S4 according to the above structural requirements.

[0019] The specific operation of step S1 is as follows: when the total area of the precious metal solution coatings on the central anode tube, cathode tube, and titanium electrode tube remains constant, design the length and number of layers of the titanium electrode tube according to actual requirements; then select titanium materials for plate heat exchangers for cutting and forming, and the grain size grade of the titanium materials needs to be controlled between 4.5 and 6.5, and the selected thickness of the titanium materials needs to be 0.25 mm more than the thickness of the finally formed titanium materials.

[0020] The specific operation of the degreasing treatment in step S2 is as follows: deburr the titanium materials cut and formed in step S1, degrease them with caustic soda, and rinse them thoroughly for standby.

[0021] The specific operation of the acid etching treatment in step S3 is as follows: etch the titanium materials that have undergone degreasing treatment in step S2 in a boiling oxalic acid solution with a mass concentration of 5%-15% until the inner and outer surfaces of the titanium tubes reach the required roughness.

[0022] The specific operation of the coating treatment in step S4 is as follows: the precious metal coating solution is composed of a mixed solution of RuCl3·3H2O, tetrabutyl titanate, chloropalladic acid, and n-butanol added with hydrochloric acid, and the mass ratio of ruthenium, palladium, and titanium is: Ru:Pd:Ti = 2:(0.6 - 1.2):(4 - 8). Apply the prepared precious metal coating solution evenly on the titanium materials treated in step S3. The coating process uses the brushing method and is sintered in an atmosphere at a temperature of 400 - 550 °C for 10 - 70 min. Repeat the above process until the precious metal coating solution is used up.

[0023] Compared with the prior art, the advantages of the present invention are as follows:

[0024] 1. A multi-layer tubular anode device for efficient chlorine evolution and its preparation method. Using a multi-layer tubular titanium electrode tube, a titanium electrode tube is arranged outside the central anode tube from the inside out, and a cathode tube is arranged outside the titanium electrode tube. The structure of the present invention is simple and easy to install, which can save a large amount of installation time. The central anode tube, titanium electrode tube, and cathode tube all adopt a hollow design, which is beneficial to saving titanium materials, reducing the mass of the generator, and the preparation cost.

[0025] 2. Since the surfaces of the titanium electrode tubes all show irregular porous shapes, it is convenient for the sodium chloride solution to flow freely in the entire generator. During the electrolysis process, the anode and cathode can be switched with each other according to actual needs, that is, reverse polarization, which is easy to switch between a common sodium hypochlorite generator and a reverse-polarized sodium hypochlorite generator, and the electrolysis of sodium chloride can be more uniform and complete.

[0026] 3. Since one end of the cathode tube and the titanium electrode tube is provided with a base, and a first support plate is arranged on one side of the base, and the other end of the cathode tube and the titanium electrode tube is configured with a sealing cover, and a second support plate is arranged on one side of the sealing cover. Compared with the existing sodium hypochlorite generators in the market, the present invention only fixes on both sides of the titanium electrode, greatly reducing the electrode short circuit caused by the increase in resistance, the sharp heat release and the melting of the polyethylene gasket.

[0027] 4. During the coating treatment, the noble metal coating solution is composed of a mixed solution of RuCl3·3H2O, tetrabutyl titanate and chloropalladic acid in n-butanol added with hydrochloric acid. The noble metal Pd is introduced to replace the noble metal Ir, greatly reducing the cost; at the same time, there are also great differences in the sintering process from the preparation processes of other electrodes. The present invention adopts a step-by-step bundling method. First, the coating is fully oxidized and then bundled to form a whole; finally, it is oxidized at a higher temperature and for a longer time, which not only ensures the adequacy of oxidation but also can bundle all the coatings as a whole to improve the bonding force.

[0028] In summary, the present invention has the characteristics of convenient operation, simple structure and cost saving. Brief Description of the Drawings

[0029] Figure 1 is the front view of the present invention.

[0030] Figure 2 is the sectional view of the present invention.

[0031] Figure 3 is the left view of the present invention.

[0032] Figure 4 is the structural schematic diagram of the titanium electrode tube in the present invention.

[0033] Wherein: 1. Central anode tube; 2. First liquid inlet; 3. Second liquid inlet; 4. First liquid outlet; 5. Cathode tube; 6. Base; 7. First support plate; 8. Sealing cover; 9. Second support plate; 10. Anode connection plate; 11. Cathode connection plate; 12. Sealing ring; 13. Titanium electrode tube; 14. Hole; 15. Second liquid outlet. Detailed Description of the Specific Embodiment

[0034] The present invention will be further described in detail below with reference to the embodiments.

[0035] Obviously, the embodiments described in the present invention only represent a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, the technical terms described herein are all commonly used in the art and are understood in the same way by those skilled in the art, and all fall within the scope of protection of the present invention.

[0036] A multi-layer tubular anode device for efficient chlorine evolution includes a central anode tube 1. The central anode tube 1 is designed with a hollow structure, which can save titanium materials and reduce costs. One end of the central anode tube 1 close to the sealing cover 8 is provided with a first liquid outlet 4, and one end of the central anode tube 1 close to the base 6 is provided with a second liquid outlet 15. The second liquid outlet 15 is communicated with the inner cavity of the titanium electrode tube 13. The sealing cover 8 is provided with a first liquid inlet 2 and a second liquid inlet 3. The first liquid inlet 2 and the second liquid inlet 3 are connected to the sodium chloride solution through pipelines. The first liquid outlet 4 is connected to a storage bucket through a pipeline. When the reaction is completed, the solution enters the central anode tube 1 through the second liquid outlet 15 and is then discharged through the first liquid outlet 4. Therefore, the central anode tube 1, the first liquid outlet 4 and the second liquid outlet 15 are arranged between the first liquid inlet 2 and the second liquid inlet 3, which can play a role in cooling the sodium hypochlorite solution. An outer layer of the central anode tube 1 is provided with a titanium electrode tube 13 from the inside out. An outer layer of the titanium electrode tube 13 is provided with a cathode tube 5. One end of the cathode tube 5 and the titanium electrode tube 13 is provided with a base 6. One side of the base 6 is provided with a first support plate 7. The other end of the cathode tube 5 and the titanium electrode tube 13 is configured with a sealing cover 8. One side of the sealing cover 8 is provided with a second support plate 9. One end of the central anode tube 1 passing through the sealing cover 8 is provided with an anode connection plate 10. The sealing cover 8 and the first liquid outlet 4 are sealed with a sealing ring 12. An outer layer of the cathode tube 5 is provided with a cathode connection plate 11. The anode connection plate 10 is connected to the positive pole of the power supply, and the cathode connection plate 11 is connected to the negative pole of the power supply.

[0037] Under the condition that the overall structure of the device remains unchanged, the coating positions of the central anode tube 1, the cathode tube 5 and the titanium electrode tube 13 can be changed according to actual needs during the electrolysis process, so as to be used as a reverse electrode or a non-reverse electrode. When used as a reverse electrode, the outer side of the central anode tube 1 has a coating and the inner side has no coating. Each layer of the titanium electrode tube 13 has coatings on both the inner and outer sides. The inner side of the cathode tube 5 has a coating and the outer side has no coating. When not used as a reverse electrode, the outer side of the central anode tube 1 has a coating and the inner side has no coating. Each layer of the titanium electrode tube 13 has no coating on the inner side and has a coating on the outer side. The inner and outer sides of the cathode tube 5 have no coatings. Reversing the electrode is beneficial to removing the scale deposited on the surface of the electrode coating during the electrolysis process and effectively maintaining the current efficiency of the electrode.

[0038] The titanium electrode tube 13 is composed of multiple layers of hollow cylindrical titanium electrodes. There are holes 14 with different sizes and uneven distributions on the surface of each layer of hollow cylindrical titanium electrode tube 13 with different diameters, and the holes are not connected to each other, which is convenient for the electrolyte solution to flow freely in the whole generator, obtain sufficient electrolysis, and at the same time obtain uniform electrolysis products.

[0039] When titanium materials are selected and the selected titanium materials are cut and formed according to requirements, when the total area of the precious metal solution coatings on the central anode tube 1, the cathode tube 5, and the titanium electrode tube 13 remains constant, the length and number of layers of the titanium electrode tube 13 are designed according to actual requirements. If the requirements are certain and the space is narrow and long, the number of layers can be reduced and the length increased; otherwise, it is the opposite.

[0040] Example 1

[0041] A preparation method of a multi-layer tubular anode device for efficient chlorine evolution includes the following steps:

[0042] S1. Select titanium materials and cut and form the selected titanium materials according to requirements. The specific operation is: when the total area of the precious metal solution coatings on the central anode tube 1, the cathode tube 5, and the titanium electrode tube 13 remains constant, the length and number of layers of the titanium electrode tube 13 are designed according to actual requirements; then select titanium materials for plate heat exchangers for cutting and forming, and the grain size grade of the titanium materials is 4.5. The thickness of the selected titanium materials needs to be 0.25 mm more than the thickness of the finally formed titanium materials;

[0043] S2. Degrease the titanium materials cut and formed in step S1. The specific operation is: deburr the titanium materials cut and formed in step S1 and degrease them with caustic soda, and rinse them clean and set aside;

[0044] S3. Acid-etch the titanium materials degreased in step S2. The specific operation is: etch the titanium materials degreased in step S2 in a boiling oxalic acid solution with a mass concentration of 10% until the inner and outer surfaces of the titanium tube reach the required roughness;

[0045] S4. Coat the titanium materials acid-etched in step S3. The specific operation is: the precious metal coating solution is composed of a mixed solution of RuCl3·3H2O, tetrabutyl titanate, chloropalladic acid, and n-butanol added with hydrochloric acid. The ruthenium content of the coating is 0.8 mg / cm2, and the palladium content is 0.4 mg / cm2. The mass ratio of ruthenium, palladium, and titanium is: Ru:Pd:Ti = 2:1:6. The prepared precious metal coating solution is evenly coated on the titanium materials treated in step S3. The brushing method used is the brushing method. For 1-5 times, sinter at 450 °C for 15 min; for the 6th time, sinter at 450 °C for 60 min; for 7-11 times, sinter at 450 °C for 15 min, and for the 12th time, sinter at 500 °C for 60 min; among them, sintering for 60 min for the 6th time is to ensure that the precious metals are completely oxidized in the first 5 sinterings and to reinforce the coatings in the first 5 times; sintering for 60 min for the last time is to ensure that the entire electrode coating is completely oxidized and to reinforce the entire electrode until the precious metal coating solution is used up;

[0046] S5. Assemble the titanium materials coated in step S4 according to the above structural requirements.

[0047] The assembled anode device is tested. The specific operation is as follows: Salt water with a mass concentration of 3% is introduced at the first liquid inlet and the second liquid inlet, and an electrolysis reaction is carried out at a current density of 1000 A / m 2 ². Finally, the effective chlorine concentration is tested at the liquid outlet.

[0048] In the prior art, when using a sodium hypochlorite generator device with a flow rate of 500 g / h and the coating remaining unchanged, the area of the electrode coating is approximately 0.6 m 2 ², the current density is 1000 A / m 2 ², the inlet water flow rate is 63 L / h, the inlet water temperature is 25 °C, the salt water has a mass concentration of 3%, and the sodium hypochlorite concentration at the outlet is approximately 6800 ppm.

[0049] When using a traditional sodium hypochlorite generator device with a flow rate of 500 g / h and the coating and the coating processing method are adopted in the manner described in the present invention, the area of the electrode coating is approximately 0.6 m 2 ², the current density is 1000 A / m 2 ², the inlet water flow rate is 63 L / h, the inlet water temperature is 25 °C, the salt water has a mass concentration of 3%, and the sodium hypochlorite concentration at the outlet is increased to 7500 ppm.

[0050] When using the multi-layer tubular anode device described in the present invention, with the designed number of layers being 3 layers and the coating and the coating processing method being adopted in the manner described in the present invention, the area of the electrode coating is approximately 0.6 m 2 ², the current density is 1000 A / m 2 ², the inlet water flow rate is 63 L / h, the inlet water temperature is 25 °C, the salt water has a mass concentration of 3%, and the sodium hypochlorite concentration at the outlet can be significantly increased to 8200 ppm.

[0051] Example 2

[0052] A preparation method of a multi-layer tubular anode device for efficient chlorine evolution includes the following steps:

[0053] S1. Select titanium materials and cut and shape the selected titanium materials according to requirements. The specific operation is as follows: When the total area of the noble metal solution coatings on the central anode tube 1, the cathode tube 5, and the titanium electrode tube 13 remains constant, design the length and number of layers of the titanium electrode tube 13 according to actual requirements; then select titanium materials for plate heat exchangers for cutting and shaping, and the grain size grade of the titanium materials is 5. The thickness of the selected titanium materials needs to be 0.25 mm more than the thickness of the finally formed titanium materials;

[0054] S2. Degrease the titanium materials cut and shaped in step S1. The specific operation is as follows: Deburr the titanium materials cut and shaped in step S1, degrease them with caustic soda, and rinse them clean for standby;

[0055] S3. Perform acid etching on the titanium material that has been degreased in step S2. The specific operation is as follows: Etch the titanium material that has been degreased in step S2 in a boiling oxalic acid solution with a mass concentration of 5% until the inner and outer surfaces of the titanium tube reach the required roughness.

[0056] S4. Perform coating on the titanium material that has been acid-etched in step S3. The specific operation is as follows: The noble metal coating solution is composed of a mixed solution of RuCl3·3H2O, tetrabutyl titanate, chloropalladic acid, and n-butanol added with hydrochloric acid. The ruthenium content in the coating is 0.8 mg / cm2, and the palladium content is 0.4 mg / cm2. The mass ratio of ruthenium, palladium, and titanium is Ru:Pd:Ti = 2:0.6:4. Uniformly coat the prepared noble metal coating solution on the titanium material processed in step S3. The brushing method used is the brushing method. Sinter at 400 °C for 10 min for 1 - 5 times; sinter at 400 °C for 60 min for the 6th time; sinter at 450 °C for 20 min for 7 - 11 times, and sinter at 500 °C for 65 min for the 12th time; among which sintering for 60 min in the 6th time ensures that the noble metal is completely oxidized in the first 5 sinterings and strengthens the coatings in the first 5 times; sintering for 65 min in the last time ensures that the entire electrode coating is completely oxidized and strengthens the entire electrode until the noble metal coating solution is used up.

[0057] S5. Assemble the titanium material that has been coated in step S4 according to the above structural requirements.

[0058] Test the assembled anode device. The specific operation is as follows: Pass brine with a mass concentration of 3% into the first liquid inlet and the second liquid inlet, and perform an electrolysis reaction at a current density of 1000 A / m 2 Finally, test the effective chlorine concentration at the liquid outlet.

[0059] In the prior art, when using a sodium hypochlorite generator device with 1000 g / h and the coating remains unchanged, the electrode coating area is about 1.2 m 2 , the current density is 1000 A / m 2 , the inlet water flow rate is 125 L / h, the inlet water temperature is 25 °C, the brine with a mass concentration of 3%, and the sodium hypochlorite concentration at the outlet is about 6500 ppm, and the temperature is 37 °C.

[0060] When using a traditional sodium hypochlorite generator device with 1000 g / h and the coating and the coating processing method adopt the method described in the present invention, the electrode coating area is about 1.2 m 2 , the current density is 1000 A / m 2 , the inlet water flow rate is 125 L / h, the inlet water temperature is 25 °C, the brine with a mass concentration of 3%, and the sodium hypochlorite concentration at the outlet is increased to 7200 ppm, and the temperature is 35 °C.

[0061] When the multi-layer tubular anode device described in the present invention is adopted, with the designed number of layers being 3 (for the same coating area, compared with 5 layers, the tubular length increases), and when the coating and the processing method of the coating adopt the methods described in the present invention, the electrode coating area is about 1.2 m 2 , the current density is 1000 A / m 2 , the influent flow rate is 125 L / h, the influent temperature is 25 °C, the brine with a mass concentration of 3%, and the sodium hypochlorite concentration at the outlet can be significantly increased to 8000 ppm, and the temperature is 32 °C.

[0062] When the multi-layer tubular anode device described in the present invention is adopted, with the designed number of layers being 5, and when the coating and the processing method of the coating adopt the methods described in the present invention, the electrode coating area is about 1.2 m 2 , the current density is 1000 A / m 2 , the influent flow rate is 125 L / h, the influent temperature is 25 °C, the brine with a mass concentration of 3%, and the sodium hypochlorite concentration at the outlet can be significantly increased to 7900 ppm, and the temperature is 33.5 °C.

[0063] Example 3

[0064] A preparation method of a multi-layer tubular anode device for efficient chlorine evolution includes the following steps:

[0065] S1. Select titanium materials and cut and form the selected titanium materials according to requirements. The specific operation is: when the total area of the noble metal solution coatings on the central anode tube 1, the cathode tube 5, and the titanium electrode tube 13 remains constant, design the length and number of layers of the titanium electrode tube 13 according to actual requirements; then select the titanium materials for plate heat exchangers for cutting and forming, and the grain size grade of the titanium materials is 6, and the thickness of the selected titanium materials needs to be 0.25 mm more than the thickness of the finally formed titanium materials;

[0066] S2. Degrease the titanium materials cut and formed in step S1. The specific operation is: deburr the titanium materials cut and formed in step S1, degrease them with caustic soda, and rinse them clean for standby;

[0067] S3. Acid-etch the titanium materials degreased in step S2. The specific operation is: etch the titanium materials degreased in step S2 in a boiling oxalic acid solution with a mass concentration of 10% until the inner and outer surfaces of the titanium tubes reach the required roughness;

[0068] S4. Perform a coating treatment on the acid-etched titanium material in step S3. The specific operation is as follows: The precious metal coating solution is composed of a mixed solution of RuCl3·3H2O, tetrabutyl titanate, chloropalladic acid, and n-butanol added with hydrochloric acid. The ruthenium content in the coating is 0.8 mg / cm2, and the palladium content is 0.4 mg / cm2. The mass ratio of ruthenium, palladium, and titanium is Ru:Pd:Ti = 2:1.2:7. The prepared precious metal coating solution is evenly coated on the titanium material treated in step S3. The brushing method used is the brushing process. For 1 - 5 times, sinter at 450 °C for 10 min; for the 6th time, sinter at 500 °C for 50 min; for 7 - 11 times, sinter at 500 °C for 25 min; for the 12th time, sinter at 550 °C for 60 min. Among them, sintering for 50 min in the 6th time ensures that the precious metals in the first 5 sinterings are completely oxidized and strengthens the coatings in the first 5 times; sintering for 60 min in the last time ensures that the entire electrode coating is completely oxidized and strengthens the entire electrode until the precious metal coating solution is used up.

[0069] S5. Assemble the titanium material that has undergone the coating treatment in step S4 according to the above structural requirements.

[0070] Test the assembled anode device. The specific operation is as follows: Pass brine with a mass concentration of 3% into the first liquid inlet and the second liquid inlet, and perform an electrolysis reaction at a current density of 1000 A / m 2 Finally, test the effective chlorine concentration at the liquid outlet.

[0071] In the prior art, for a 5000 g / h sodium hypochlorite generator device, when the coating remains unchanged, the electrode coating area is approximately 6 m 2 with a current density of 1000 A / m 2 , an inlet water flow rate of 625 L / h, an inlet water temperature of 25 °C, brine with a mass concentration of 3%, and the sodium hypochlorite concentration at the outlet is approximately 6400 ppm, and the temperature is 39 °C.

[0072] When using a traditional 5000 g / h sodium hypochlorite generator device and adopting the coating and coating processing method described in the present invention, the electrode coating area is approximately 6 m 2 with a current density of 1000 A / m 2 , an inlet water flow rate of 625 L / h, an inlet water temperature of 25 °C, brine with a mass concentration of 3%, and the sodium hypochlorite concentration at the outlet is increased to 7000 ppm, and the temperature is 37 °C.

[0073] When using the multi-layer tubular anode device described in the present invention with a designed number of layers of 5 (for the same coating area, compared with 10 layers, the tubular length increases) and adopting the coating and coating processing method described in the present invention, the electrode coating area is approximately 6 m 2 with a current density of 1000 A / m 2, with an influent flow rate of 625 L / h, an influent temperature of 25 °C, brine with a mass concentration of 3%, the sodium hypochlorite concentration at the outlet can be significantly increased to 7800 ppm, and the temperature is 34 °C.

[0074] When the multi-layer tubular anode device described in the present invention is adopted, the designed number of layers is 10 layers, and when the coating and the processing method of the coating adopt the method described in the present invention, the electrode coating area is about 6 m 2 , the current density is 1000 A / m 2 , with an influent flow rate of 625 L / h, an influent temperature of 25 °C, brine with a mass concentration of 3%, the sodium hypochlorite concentration at the outlet can be significantly increased to 7630 ppm, and the temperature is 35.5 °C.

[0075] The working principle of the present invention is:

[0076] Prepare a sodium chloride solution with the required mass concentration, and pass the prepared sodium chloride solution into the multi-layer tubular anode device through a mechanical pump. The first liquid inlet 2 and the second liquid inlet 3 provided on the sealing cover 8 are respectively connected to a flow meter, and the flow meter is used to control the liquid inlet flow rate; the sodium chloride solution fills the entire multi-layer tubular anode device and can flow in the anode device through the holes on the surface of the titanium electrode tube 13. Then connect the anode connecting plate 10 to the positive pole of the power supply, and connect the cathode connecting plate 11 to the negative pole of the power supply. Turn on the power supply for electrolysis; the solution after electrolysis enters the central anode tube 1 through the second liquid outlet 15 provided on the central anode tube 1, and then flows out from the first liquid outlet 4.

Claims

1. A multi-layer tubular anode device for efficient chlorine evolution, characterized in that It includes a central anode tube (1), an outer layer of the central anode tube (1) is sleeved with a titanium electrode tube (13), an outer layer of the titanium electrode tube (13) is sleeved with a cathode tube (5), one end of the central anode tube (1) exposed from the titanium electrode tube (13) is provided with an anode connection plate (10), and an outer layer of the cathode tube (5) is provided with a cathode connection plate (11); the titanium electrode tube (13) is composed of multiple layers of hollow cylindrical titanium electrodes, and holes (14) of different sizes and uneven distributions exist on the surfaces of each layer of hollow cylindrical titanium electrode tubes (13) with different diameters, and the holes are not connected to each other.

2. The multi-layer tubular anode device for efficient chlorine evolution according to claim 1, characterized in that, One end of the cathode tube (5) and the titanium electrode tube (13) is provided with a base (6), one side of the base (6) is provided with a first support plate (7), the other end of the cathode tube (5) and the titanium electrode tube (13) is configured with a sealing cover (8), and one side of the sealing cover (8) is provided with a second support plate (9).

3. An efficient chlorine evolution multi-layer tubular anode device according to claim 2, characterized in that, The sealing cover (8) is provided with a first liquid inlet (2) and a second liquid inlet (3), both the first liquid inlet (2) and the second liquid inlet (3) communicate with the inner cavity of the titanium electrode tube (13), one end of the central anode tube (1) close to the sealing cover (8) is provided with a first liquid outlet (4), one end of the central anode tube (1) close to the base (6) is provided with a second liquid outlet (15), the second liquid outlet (15) is connected to the inner cavity of the titanium electrode tube (13), the first liquid inlet (2) and the second liquid inlet (3) are connected to a sodium chloride solution through pipelines, and the first liquid outlet (4) is connected to a liquid storage bucket through a pipeline.

4. The multi-layer tubular anode device for efficient chlorine evolution according to claim 1, characterized in that, During the electrolysis process, the positions of the coatings on the central anode tube (1), the cathode tube (5) and the titanium electrode tube (13) can be changed according to actual needs, so as to be used as a reverse electrode or a non-reverse electrode; when used as a reverse electrode, there is a coating on the outer side of the central anode tube (1) and no coating on the inner side, there are coatings on both the inner and outer sides of each layer of the titanium electrode tube (13), and there is a coating on the inner side of the cathode tube (5) and no coating on the outer side; when not used as a reverse electrode, there is a coating on the outer side of the central anode tube (1) and no coating on the inner side, there is no coating on the inner side of each layer of the titanium electrode tube (13) and a coating on the outer side, and there are no coatings on both the inner and outer sides of the cathode tube (5).

5. An efficient chlorine evolution multi-layer tube anode device according to claim 4, characterized in that, The coating is coated with a precious metal coating solution, and the precious metal coating solution is composed of a mixed solution of RuCl3·3H2O, tetrabutyl titanate, chloropalladic acid and n-butanol added with hydrochloric acid, and the mass ratio of ruthenium, palladium and titanium is: Ru:Pd:Ti = 2:(0.6 - 1.2):(4 - 8).

6. A preparation method of a multi-layer tubular anode device for efficient chlorine evolution, characterized in that, It includes the following steps: S1. Select titanium materials and cut and shape the selected titanium materials according to requirements. The specific operation is: when the total area of the precious metal solution coatings on the central anode tube (1), the cathode tube (5) and the titanium electrode tube (13) remains constant, design the length and number of layers of the titanium electrode tube (13) according to actual needs; then select titanium materials for plate heat exchangers for cutting and shaping, and the grain size grade of the titanium materials needs to be controlled between 4.5 - 6.5, and the thickness of the selected titanium materials needs to be 0.25 mm more than the thickness of the finally formed titanium materials. S2. Degrease the titanium materials cut and shaped in step S1. The specific operation is: deburr the titanium materials cut and shaped in step S1, degrease them with caustic soda, and rinse them clean for standby. S3. Acid-etch the titanium material that has been degreased in step S2. The specific operation is as follows: Etch the titanium material that has been degreased in step S2 in a boiling oxalic acid solution with a mass concentration of 5-15% until the inner and outer surfaces of the titanium tube reach the required roughness. S4. Coat the titanium material that has been acid-etched in step S3. The specific operation is as follows: The noble metal coating solution is composed of a mixed solution of RuCl3·3H2O, tetrabutyl titanate, chloropalladic acid, and n-butanol added with hydrochloric acid. The mass ratio of ruthenium, palladium, and titanium is Ru:Pd:Ti = 2:(0.6-1.2):(4-8). Coat the prepared noble metal coating solution evenly on the titanium material processed in step S3. The brushing method is used during the coating process, and sintering is carried out for 10-70 minutes in an atmosphere at a temperature of 400-550 °C. Repeat the above process until the noble metal coating solution is exhausted. S5. Assemble the titanium material that has been coated in step S4 according to the device described in any one of claims 1 to 5.

7. The preparation method of a multi-layer tubular anode device for efficient chlorine evolution according to claim 6, characterized in that, It includes the following steps: S1. Select titanium material and cut and shape the selected titanium material according to requirements. The specific operation is as follows: When the total area of the noble metal solution coating on the central anode tube (1), the cathode tube (5), and the titanium electrode tube (13) remains constant, design the length and number of layers of the titanium electrode tube (13) according to actual requirements. Then select titanium material for plate heat exchangers and cut and shape it. The grain size grade of the titanium material is 4.5, and the thickness of the selected titanium material should be 0.25 mm more than the thickness of the finally formed titanium material. S2. Degrease the titanium material cut and shaped in step S1. The specific operation is as follows: Deburr the titanium material cut and shaped in step S1, degrease it with caustic soda, and rinse it clean for standby. S3. Acid-etch the titanium material that has been degreased in step S2. The specific operation is as follows: Etch the titanium material that has been degreased in step S2 in a boiling oxalic acid solution with a mass concentration of 10% until the inner and outer surfaces of the titanium tube reach the required roughness. S4. Coat the titanium material that has been acid-etched in step S3. The specific operation is as follows: The noble metal coating solution is composed of a mixed solution of RuCl3·3H2O, tetrabutyl titanate, chloropalladic acid, and n-butanol added with hydrochloric acid. The ruthenium content of the coating is 0.8 mg / cm2, and the palladium content is 0.4 mg / cm2. The mass ratio of ruthenium, palladium, and titanium is Ru:Pd:Ti = 2:1:

6. Coat the prepared noble metal coating solution evenly on the titanium material processed in step S3. The brushing method used is the brushing method. Sinter for 15 minutes at 450 °C for 1-5 times; sinter for 60 minutes at 450 °C for the 6th time; sinter for 15 minutes at 450 °C for 7-11 times, and sinter for 60 minutes at 500 °C for the 12th time. Among them, sintering for 60 minutes for the 6th time ensures that the noble metal is completely oxidized in the first 5 sinterings and strengthens the coatings in the first 5 times; sintering for 60 minutes for the last time ensures that the entire electrode coating is completely oxidized and strengthens the entire electrode until the noble metal coating solution is exhausted. S5. Assemble the titanium material that has been coated in step S4 according to the device described in any one of claims 1 to 5.

8. The preparation method of a multi-layer tubular anode device for efficient chlorine evolution according to claim 6, characterized in that, It includes the following steps: S1. Select titanium material and cut and shape the selected titanium material according to requirements. The specific operation is as follows: When the total area of the noble metal solution coatings on the central anode tube (1), the cathode tube (5), and the titanium electrode tube (13) remains constant, design the length and number of layers of the titanium electrode tube (13) according to actual requirements; then select titanium material for plate heat exchangers for cutting and shaping, and the grain size grade of the titanium material is 5. The thickness of the selected titanium material should be 0.25 mm more than the thickness of the finally formed titanium material. S2. Degrease the titanium material cut and shaped in step S1. The specific operation is as follows: Deburr the titanium material cut and shaped in step S1 and degrease it with caustic soda, and set it aside after rinsing clean. S3. Acid-etch the titanium material that has been degreased in step S2. The specific operation is as follows: Etch the titanium material that has been degreased in step S2 in a boiling oxalic acid solution with a mass concentration of 5% until the inner and outer surfaces of the titanium tube reach the required roughness. S4. Coat the titanium material that has been acid-etched in step S3. The specific operation is as follows: The noble metal coating solution is composed of RuCl3·3H2O, tetrabutyl titanate, chloropalladic acid, and a mixed solution of n-butanol with hydrochloric acid added. The ruthenium content of the coating is 0.8 mg / cm2, and the palladium content is 0.4 mg / cm2. The mass ratio of ruthenium, palladium, and titanium is: Ru:Pd:Ti = 2:0.6:

4. Apply the prepared noble metal coating solution evenly on the titanium material treated in step S3. The brushing method used is the brushing method. Sinter at 400 °C for 10 min for 1 - 5 times; sinter at 400 °C for 60 min for the 6th time; sinter at 450 °C for 20 min for 7 - 11 times, and sinter at 500 °C for 65 min for the 12th time; Among them, sintering for 60 min in the 6th time ensures that the noble metals are completely oxidized in the first 5 sinterings and strengthens the coatings in the first 5 times; sintering for 65 min in the last time ensures that the entire electrode coating is completely oxidized and strengthens the entire electrode until the noble metal coating solution is used up. S5. Assemble the titanium material that has been coated in step S4 according to the device described in any one of claims 1 to 5.

9. The preparation method of a multi-layer tubular anode device for efficient chlorine evolution according to claim 6, characterized in that, It includes the following steps: S1. Select titanium material and cut and shape the selected titanium material according to requirements. The specific operation is as follows: When the total area of the noble metal solution coatings on the central anode tube (1), the cathode tube (5), and the titanium electrode tube (13) remains constant, design the length and number of layers of the titanium electrode tube (13) according to actual requirements; then select titanium material for plate heat exchangers for cutting and shaping, and the grain size grade of the titanium material is 6. The thickness of the selected titanium material should be 0.25 mm more than the thickness of the finally formed titanium material. S2. Degrease the titanium material cut and shaped in step S1. The specific operation is as follows: Deburr the titanium material cut and shaped in step S1 and degrease it with caustic soda, and set it aside after rinsing clean. S3. Acid-etch the degreased titanium material in step S2. The specific operation is as follows: Etch the degreased titanium material in step S2 in a boiling oxalic acid solution with a mass concentration of 10% until the inner and outer surfaces of the titanium tube reach the required roughness. S4. Coat the acid-etched titanium material in step S3. The specific operation is as follows: The noble metal coating solution is composed of a mixed solution of RuCl3·3H2O, tetrabutyl titanate, chloropalladic acid, and n-butanol added with hydrochloric acid. The ruthenium content in the coating is 0.8 mg / cm2, and the palladium content is 0.4 mg / cm2. The mass ratio of ruthenium, palladium, and titanium is Ru:Pd:Ti = 2:1.2:

7. The prepared noble metal coating solution is evenly coated on the titanium material treated in step S3. The brushing method used is the brushing method. For 1-5 times, sinter at 450 °C for 10 min; for the 6th time, sinter at 500 °C for 50 min; for 7-11 times, sinter at 500 °C for 25 min; for the 12th time, sinter at 550 °C for 60 min until the noble metal coating solution is used up. Among them, sintering for 50 min in the 6th time ensures that the noble metal is completely oxidized in the first 5 sinterings and strengthens the coatings in the first 5 times; sintering for 60 min in the last time ensures that the entire electrode coating is completely oxidized and strengthens the entire electrode until the noble metal coating solution is used up. S5. Assemble the coated titanium material in step S4 according to the device described in any one of claims 1 to 5.

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