WO2022006749A1

WO2022006749A1 - Membrane polar distance ion membrane electrolyzer

Info

Publication number: WO2022006749A1
Application number: PCT/CN2020/100697
Authority: WO
Inventors: 乔霄峰; 张丽蕊; 刘秀明; 许东全; 王小磊; 陆崖青; 宗子超; 郭瑾; 范峰; 王新怡
Original assignee: 蓝星(北京)化工机械有限公司
Priority date: 2020-07-07
Filing date: 2020-07-07
Publication date: 2022-01-13
Also published as: MX2022013869A

Abstract

A membrane polar distance ion membrane electrolyzer, comprising a plurality of frames which are arranged side by side, wherein frame faces of the plurality of frames are located in a front-back vertical direction; the frame faces of adjacent frames are closely attached to each other; a sealing member for sealing a gap between attached faces of the frames is arranged between the frame faces of the adjacent frames; one side of each frame is provided with a cathode chamber, and the other side of the frame is provided with an anode chamber; a composite board capable of conducting electricity is arranged between the anode chamber and the cathode chamber; and the cathode chambers and the anode chambers on the plurality of frames are disposed spaced apart from each other in the order of one cathode chamber, one anode chamber, another cathode chamber and another anode chamber. The purpose of the present invention lies in providing a membrane polar distance ion membrane electrolyzer which can reduce a liquid concentration difference in an electrolytic chamber, improve the current operation efficiency and reduce electrolysis energy, and can effectively protect an ion membrane, such that stress is applied to the ion membrane more uniformly, a buffer net also has a good resilience effect after being stressed, and the service life of the ion membrane can be prolonged, while the conductive and elastic effects thereof are also ensured.

Description

Membrane distance sub-membrane electrolytic cell

technical field

The invention relates to a membrane electrode distance sub-membrane electrolytic cell.

Background technique

The liquid dispersion structure of the current electrolytic cell is generally located in the electrolysis chamber, or the liquid dispersion structure itself is not provided. The electrolyte in the lower part of the liquid dispersion structure of the former cannot flow well, and it is easy to generate a dead zone of circulation; while the uniform distribution of the electrolyte of the latter is poor, which is likely to cause a large difference in liquid concentration in the electrolysis chamber, which in turn reduces the operating current efficiency. lower, the energy consumption of electrolysis becomes larger.

In addition, when the distance between the membrane electrode and the sub-membrane electrolytic cell is in operation, the distance between the cathode and anode can achieve the effect of the distance between the cathode and anode. It is mainly by setting a buffer net on the cathode side, and the buffer net is used to control the pressure during the operation of the electrolytic cell. accomplish. However, most of the existing buffer nets are formed by pressing in one-way or symmetrical directions. During the production and operation of this kind of buffer structure, the force is easily released to one side, that is, a large deformation occurs in the long-side direction, which will lead to The large displacement of the buffer structure and the aggravated loss of elasticity make the ion membrane stress unevenly, thereby shortening the service life of the ion membrane.

In addition, the titanium-based noble metal coating used in the chlorine evolution electrode in the traditional electrolysis device effectively reduces the chlorine evolution overpotential of the anode and reduces the operating energy consumption. However, expensive precious metals need to be consumed to make coatings, and the cost of electrodes is greatly affected by the price of precious metal raw materials. In recent years, the market demand for precious metals has continued to expand, and resource consumption has increased sharply, resulting in continued price increases of precious metals, especially in the process of chlorine evolution reaction. The precious metals Ru and Ir, which are the main catalytic functions, lead to a sharp increase in the cost of electrode manufacturing, and a new coating that can both realize the catalytic function of the electrode and reduce the cost is very much needed.

Under normal circumstances, the coating cost can be controlled by controlling the amount of precious metals Ru and Ir used in the production of anode coatings. However, since Ru and Ir catalysts are continuously consumed at a certain rate during the anode chlorine evolution reaction, if the amount is small, The life of the anode will be affected and it cannot meet the needs of users.

Studies have shown that the cheap Sn element can form metal oxide crystals with the same structure as Ru, Ir and Ti, and can refine the electrode surface coating particles and improve the catalytic activity of the electrode, which can be used to reduce the cost of chlorine evolution anode and ensure the life of the anode. . The Ru, Ir and Sn electrodes prepared in De Nora's CN200980144577.7 patent have a chlorine evolution overpotential of 60mV at a relatively low operating current density, and need to be modified by adding expensive platinum, palladium, etc., which is not conducive to electrode cost control. Moreover, the bonding force between Pt and Pd metal oxides and the metal oxides of Ru, Ir and Sn is not good, and it is difficult to guarantee the life of the anode.

In view of the problems of expensive multi-layer coating and short service life of existing chlorine gas evolution anodes, it is necessary to research and manufacture chlorine gas evolution anodes that can not only ensure a good anode service life, but also effectively reduce the cost of coating production and simplify the electrode production process.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method that can reduce the liquid concentration difference in the electrolysis chamber, improve the current operation efficiency, reduce the electrolytic energy, and effectively protect the ionic membrane, so that the ionic membrane is more uniformly stressed, and the buffer net is also stressed. It has a good rebound effect, which can ensure the gap between the cathode and anode, and can improve the service life of the ion membrane while ensuring the conductivity and elastic effect. At the same time, the amount of precious metals ruthenium and iridium is small, and the manufacturing cost of the anode is low , The bonding force between metal oxides is large, the service life is long, and the catalytic activity is high, which can effectively reduce the anode chlorine evolution overpotential and reduce the electric energy consumption.

The membrane electrode distance sub-membrane electrolytic cell of the present invention includes a plurality of frames arranged in parallel, the frame surfaces of the plurality of frames are located in the front and rear vertical directions, the frame surfaces of the adjacent frames are arranged in close contact with each other, and the frame surfaces of the adjacent frames are arranged in close contact with each other. There is a seal for sealing the gap between the mating surfaces of the frame;

One side of the frame is provided with a cathode compartment, the other side is provided with an anode compartment, a conductive composite plate is arranged between the anode compartment and the cathode compartment, and the cathode compartments and anode compartments on multiple frames are arranged according to one cathode compartment, The sequence of one anode chamber, another cathode chamber, and another anode chamber is spaced apart from each other;

The cathode chamber of each frame and the anode chamber of an adjacent frame respectively form a membrane distance sub-membrane electrolytic cell unit, and each membrane distance sub-membrane electrolytic cell unit is provided with a The ion-exchange membrane separating the cathode chamber and the anode chamber of the membrane electrolyzer unit, the ion-exchange membrane is located in the front and rear vertical directions;

The bottom of the cathode chamber is provided with a row of cathode chamber liquid inlet holes along the front and rear directions. The cathode chamber liquid inlet holes communicate with the cathode chamber liquid inlet channel located below the cathode chamber in the frame. The cathode chamber is provided with a cathode chamber guide plate. The plate surface of the chamber guide plate is located in the front-rear direction, the cathode chamber guide plate is inclined, and the horizontal distance between the top end of the cathode chamber guide plate and the cathode is smaller than the horizontal distance between the bottom end of the cathode chamber guide plate and the cathode ;

The bottom of the anode chamber is provided with a row of anode chamber liquid inlet holes along the front and rear directions. The anode chamber liquid inlet holes are communicated with the anode chamber liquid inlet channel located below the anode chamber in the frame. The anode chamber is provided with an anode chamber guide plate. The plate surface of the chamber guide plate is located in the front and rear direction, the anode chamber guide plate is inclined and the horizontal distance between the top end of the anode chamber guide plate and the anode is smaller than the horizontal distance between the bottom end of the anode chamber guide plate and the anode;

In the cathode chamber of each membrane electrode distance sub-membrane electrolytic cell unit, a cathode is installed at the end of the cathode chamber where the ion exchange membrane is arranged, and the plate surface of the cathode is located in the front and rear vertical directions; one surface of the cathode exchanges with the corresponding ion exchange membrane. One surface of the membrane is attached to each other, the other surface of the cathode is attached to the mesh surface of a buffer net, the other mesh surface of the buffer mesh is attached to a surface of the cathode bottom mesh, and the cathode bottom mesh is fixed in the cathode chamber;

In the anode chamber of each membrane electrode distance sub-membrane electrolytic cell unit, an anode is installed at the end of the anode chamber where the ion exchange membrane is arranged, and the plate surface of the anode is located in the front and rear vertical directions;

A cathode gas-liquid separation chamber is arranged above the cathode chamber in the frame, and an elongated cathode gas-liquid separation chamber is provided at the bottom of the cathode gas-liquid separation chamber near the cathode of the cathode gas-liquid separation chamber. There is a cathode gas-liquid separation chamber return port at the bottom of the cathode gas-liquid separation chamber close to the composite plate of the cathode gas-liquid separation chamber, and the cathode gas-liquid separation chamber is provided with a cathode gas-liquid for breaking foam along the front and rear directions. Separation filter screen, the edge of the cathode gas-liquid separation filter screen is fixedly connected with the inner wall of the cathode gas-liquid separation chamber;

An anode gas-liquid separation chamber is arranged above the anode chamber in the frame, and a long-shaped anode gas-liquid separation chamber liquid inlet is arranged at the bottom of the anode gas-liquid separation chamber near the anode of the anode gas-liquid separation chamber. The anode gas-liquid separation chamber is provided with an anode gas-liquid separation chamber return port at the bottom of the anode gas-liquid separation chamber near the composite plate of the anode gas-liquid separation chamber, and an anode gas-liquid separation filter screen for breaking foam is arranged in the cathode gas-liquid separation chamber along the front and rear directions. , the edge of the anode gas-liquid separation filter screen is fixedly connected with the inner wall of the anode gas-liquid separation chamber;

The side walls of the cathode gas-liquid separation chamber and the anode gas-liquid separation chamber are respectively provided with drain pipes;

The mesh surface of the buffer net is corrugated, and there are a plurality of bar-shaped convex parts arranged in parallel on the mesh surface of the buffer net. The convex part has at least 3 bending sections, and the adjacent bending sections pass through corresponding connected by the bending connection;

The anode comprises a metal substrate, and the surface of the metal substrate is coated with a metal oxide coating with catalytic effect, and the metal oxide coating is composed of metal oxides of ruthenium, iridium, titanium and tin. The metal oxide coating is composed of metal oxides, and in the metal oxide coating, the molar ratio of ruthenium element is 7%-15%, the molar ratio of iridium element is 1%-4.8%, and the molar ratio of titanium element is 1% %-15%, the molar ratio of tin element is 75%-90%;

The mass percentages of ruthenium element, iridium element, titanium element and tin element in the metal oxide coating according to the metal components in the metal oxide coating can be detected by an x-ray fluorescence tester.

In the membrane electrode distance sub-membrane electrolytic cell of the present invention, the included angle a between the adjacent bending sections is not less than 90°.

In the membrane electrode distance sub-membrane electrolytic cell of the present invention, the top of the guide plate in the cathode chamber is connected with the top of the cathode chamber, the top of the guide plate in the anode chamber is connected with the top of the anode chamber, and each of the protrusions has 4-10 bending sections, the corrugated shape of the mesh surface is wavy line or undulating line, and the included angle a between the adjacent bending sections is 110°-160°.

In the membrane electrode distance sub-membrane electrolytic cell of the present invention, the buffer net is formed by overlapping the net surfaces of the multi-layer metal nets, and the angle a between the adjacent bending sections is 120°-150°.

In the membrane electrode distance sub-membrane electrolytic cell of the present invention, the height of the buffer net is 2-10 mm, and the included angle a between the adjacent bending sections is 130°-150°.

In the membrane electrode distance sub-membrane electrolytic cell of the present invention, the number of the metal mesh is 2-4 layers, the diameter of the metal wire used for the woven metal mesh is 0.1-0.6 mm, and the cathode is made of metal nickel, The anode is made of metallic titanium.

In the membrane electrode distance sub-membrane electrolytic cell of the present invention, the bending connection portion is arc-shaped.

In the membrane electrode distance sub-membrane electrolytic cell of the present invention, the porosity of the cathode and the anode are respectively 30%-60%; the aperture of the liquid inlet hole of the anode chamber is 1mm-3mm, and the aperture of the liquid inlet hole of the cathode chamber is 1mm -3mm; the thickness of the anode is 1mm-1.5mm.

The membrane electrode of the invention is far from the sub-membrane electrolytic cell, so that the reacted electrolyte can flow back to the inlet hole of the cathode chamber under the cathode chamber, and fully mix with the electrolyte from each inlet hole of the cathode chamber, thereby reducing the reduction of the electrolyte in the cathode chamber. At the same time, the reacted electrolyte can be returned to the anode chamber inlet hole below the anode chamber, and fully mixed with the electrolyte from each cathode chamber inlet hole to reduce the concentration difference of the electrolyte in the anode chamber. By introducing the reacted electrode solution into the bottom inlet of the electrolysis chamber to mix with the electrolyte that has not reacted or rarely reacted, the concentration difference between the bottom and the top of the electrolysis chamber is reduced, which is more conducive to balancing the ion concentration of the electrolyte in the electrolysis chamber, and also It is more conducive to effectively conduct the reaction heat and reduce the temperature difference in the electrolysis chamber.

However, in the buffer net in the membrane electrode distance sub-membrane electrolytic cell of the present invention, each convex part has a plurality of bending sections, that is, each convex part includes at least two inflection points, which can maintain the maximum The elastic effect of the buffer net avoids the release of the force generated by the buffer net along the long side of the net and the displacement and deformation along the long side of the net under the state of plane compression, so that the structure of the net will occur. Asymmetric, disproportionate deformation affects the elasticity of the buffer net. Because the structure of multiple bending segments will produce displacement deformation along the direction of different bending segments under the state of plane compression, and generate force and deformation released in the opposite direction to the adjacent bending segments. The force of the buffer net is more uniform, and at the same time, the buffer net has a good rebound effect after being stressed.

Therefore, the membrane electrode distance sub-membrane electrolysis cell of the present invention can reduce the liquid concentration difference in the electrolysis chamber, improve the current operation efficiency, reduce the electrolysis energy, effectively protect the ion membrane, make the ion membrane stress more uniform, and also The buffer net has a good rebound effect after being stressed, and the gap between the cathode and anode is well guaranteed, and the service life of the ion membrane can be improved under the condition of ensuring electrical conductivity and elastic effect. Compared with the prior art, the membrane electrode distance sub-membrane electrolytic cell of the present invention has outstanding substantive features and remarkable progress.

The anode of the present invention was immersed in a 95° C., 32w% NaOH solution for 8 hours for enhanced electrolytic corrosion to test the weight loss of the metal oxide coating and evaluate the life of the coating. The results show that the life of the metal oxide coating on the anode of the present invention is The weight loss (mg) is 2.9mg-3.3mg, while the life-time weight loss (mg) of the metal oxide coating on the existing anode is usually 4.0mg-6.0mg, which shows that the life-time weight loss of the electrode of the present invention is optimized, and at the same time The content of precious metals Ru and Ir in the prepared chlorine gas precipitation electrode coating is significantly reduced, and the electrode manufacturing cost is also significantly reduced.

The anode of the present invention is electrolyzed at 90 DEG C and 3.5mol/L NaCl solution, and the electrode chlorine evolution overpotential is 33.7mV-40.4mV under the test 4KA/m current density, while in the prior art, the electrode under 4KA/m current density is 33.7mV-40.4mV. The chlorine evolution overpotential is usually above 60mV, which shows that the anode of the present invention has excellent operating performance under high current density, effectively reduces the chlorine evolution overpotential of the electrode, and has a remarkable energy saving effect.

In the preparation process of the present invention, all inorganic compounds are used, and no organic solvent is used, and the coating production process is very simple, thereby reducing the difficulty and cost of electrode fabrication, and avoiding various disadvantages brought by organic solvents to operators. Influence.

The preparation method of the anode of the present invention uses an appropriate proportion of divalent tin in the preparation of the coating solution, thereby realizing that the electrode surface coating particles can be refined without adding expensive platinum, palladium and other elements, and at the same time The catalytic activity of the electrode is improved, thereby reducing the energy consumption of the chlor-alkali electrolysis and controlling the cost of the electrode.

Different from tetravalent tin, the deposition amount of Sn in the electrode coating made of the coating solution composed of divalent tin is higher than 70% and can be stably controlled, while tetravalent tin has high volatility during high temperature oxidation, resulting in tin in The deposition in the coating is less than 30% and the composition is not controllable. At the same time, since divalent tin easily undergoes redox reactions with other elements in the coating solution and forms complexes, the oxides obtained during thermal oxidation are more uniformly distributed, more tightly bound, and the size of metal oxide particles is significantly refined, Helps prolong the life of the anode and reduce the chlorine evolution potential of the electrode. At the same time, the inorganic salt of divalent tin is easy to obtain in the market, has low price and can be directly used in the preparation of coating liquid, which not only simplifies the coating production process, but also reduces the cost of raw materials.

Due to the above-mentioned unique technical features of the present invention, the present invention has the advantages that the amount of precious metals ruthenium and iridium is small, the manufacturing cost of the anode is low, the bonding force between metal oxides is large, the service life is long, and the catalytic activity is high, which can effectively reduce Anode chlorine evolution overpotential, reducing power consumption, very suitable for chlorine production electrolytic cell anode, environmental protection and high efficiency, almost no pollutants efflux characteristics.

Other details and features of the membrane electrode distance sub-membrane electrolytic cell of the present invention can be clearly understood by reading the embodiments described in detail below in conjunction with the accompanying drawings.

Description of drawings

Fig. 1 is the front view of the structural representation of the membrane electrode distance sub-membrane electrolyzer of the present invention;

Fig. 2 is the side view of Fig. 1;

Fig. 3 is the top view of the bottom plate part of the cathode chamber of the membrane electrode distance sub-membrane electrolytic cell of the present invention;

Fig. 4 is the perspective view of the structure schematic diagram of the buffer net for the membrane electrode distance sub-membrane electrolyzer of the present invention;

5 is a schematic structural diagram of the buffer mesh for the membrane electrode distance sub-membrane electrolytic cell of the present invention along the mesh surface direction;

6 is a perspective view of another embodiment of the buffer net for the membrane electrode distance sub-membrane electrolytic cell of the present invention;

Fig. 7 is the structural representation that the buffer net for the membrane electrode distance sub-membrane electrolyzer of the present invention is in use;

Fig. 8 is a kind of structural representation of the buffer net of the membrane electrode distance sub-membrane electrolytic cell of the present invention in the lateral direction of the net;

FIG. 9 is another structural schematic diagram of the buffer mesh for the membrane electrode distance sub-membrane electrolytic cell of the present invention in the lateral direction of the mesh.

detailed description

As shown in Figure 1, Figure 2 and Figure 3, the membrane electrode distance sub-membrane electrolytic cell of the present invention includes a plurality of frames 1 arranged in parallel, the frame surfaces of the plurality of frames 1 are located in the front and rear vertical directions, and the adjacent frames 1 The frame surfaces are arranged in close contact with each other, and a sealing member 2 for sealing the gap between the adhering surfaces of the frame 1 is provided between the frame surfaces of the adjacent frames 1;

One side of the frame 1 is provided with a cathode chamber 5 and the other side is provided with an anode chamber 4, a conductive composite plate 3 is provided between the anode chamber 4 and the cathode chamber 5, and the cathode chambers 5 on the intermediate multiple frames 1 are provided. and the anode chamber 4 are spaced apart from each other in the order of one cathode chamber 5, one anode chamber 4, another cathode chamber 5, and another anode chamber 4;

The cathode chamber 5 of each frame 1 and the anode chamber 4 of the adjacent frame 1 respectively form a membrane distance sub-membrane electrolytic cell unit, and each membrane distance sub-membrane electrolytic cell unit is provided with a The membrane electrode is separated from the ion exchange membrane 6 of the cathode chamber 5 and the anode chamber 4 of the sub-membrane electrolytic cell unit, and the ion exchange membrane 6 is located in the front and rear vertical directions;

The bottom of the cathode chamber 5 is provided with a row of cathode chamber liquid inlet holes 7 along the front and rear directions, and the cathode chamber liquid inlet holes 7 communicate with the cathode chamber liquid inlet channel 8 located below the cathode chamber 5 in the frame 1. There is a cathode chamber guide plate 10, the plate surface of the cathode chamber guide plate 10 is located in the front-rear direction, the cathode chamber guide plate 10 is inclined, and the horizontal distance between the top of the cathode chamber guide plate 10 and the cathode 12 is smaller than that of the cathode chamber. The horizontal distance between the bottom end of the deflector 10 and the cathode 12;

The bottom of the anode chamber 4 is provided with a row of anode chamber liquid inlet holes 9 along the front and rear directions. The anode chamber liquid inlet holes 9 communicate with the anode chamber liquid inlet channel 22 located under the anode chamber 4 in the frame 1. There is an anode chamber guide plate 11, the plate surface of the anode chamber guide plate 11 is located in the front and rear direction, the anode chamber guide plate 11 is inclined and the horizontal distance between the top of the anode chamber guide plate 11 and the anode 13 is smaller than that of the anode chamber guide plate The horizontal distance between the bottom end of the plate 11 and the anode 13;

In the cathode chamber 5 of each membrane electrode distance sub-membrane electrolytic cell unit, a cathode 12 is installed at the end of the cathode chamber 5 where the ion exchange membrane 6 is provided, and the plate surface of the cathode 12 is located in the front and rear vertical directions; one of the cathodes 12 The surface is attached to one surface of the corresponding ion exchange membrane 6, the other surface of the cathode 12 is attached to the mesh surface of a buffer mesh 23, the other mesh surface of the buffer mesh 23 is attached to a surface of the cathode bottom mesh 24, and the cathode is attached. The bottom net 24 is fixed in the cathode chamber 5;

In the anode chamber 4 of each membrane distance sub-membrane electrolytic cell unit, an anode 13 is installed at the end of the anode chamber 4 where the ion exchange membrane 6 is arranged, and the plate surface of the anode 13 is located in the front and rear vertical directions;

In the frame 1, a cathode gas-liquid separation chamber 14 is arranged above the cathode chamber 5, and a long cathode is arranged at the bottom of the cathode gas-liquid separation chamber 14 close to the side of the cathode 12 of the cathode gas-liquid separation chamber 14. The gas-liquid separation chamber liquid inlet 15 is provided with a cathode gas-liquid separation chamber return port 16 at the bottom of the cathode gas-liquid separation chamber 14 near the composite plate 3 of the cathode gas-liquid separation chamber 14, and the cathode gas-liquid separation chamber 14 A cathode gas-liquid separation filter screen 17 for breaking foam is arranged in the front and rear directions, and the edge of the cathode gas-liquid separation filter screen 17 is fixedly connected to the inner wall of the cathode gas-liquid separation chamber 14;

In the frame 1, an anode gas-liquid separation chamber 18 is arranged above the anode chamber 4, and a strip-shaped anode gas is provided at the bottom of the anode gas-liquid separation chamber 18 near the anode 13 of the anode gas-liquid separation chamber 18. The liquid inlet 19 of the liquid separation chamber, the anode gas-liquid separation chamber return port 20 is provided at the bottom of the anode gas-liquid separation chamber 18 near the composite plate 3 of the anode gas-liquid separation chamber 18, and the cathode gas-liquid separation chamber 14 has an inner edge along the front and rear edges. The direction is provided with an anode gas-liquid separation filter screen 21 for breaking foam, and the edge of the anode gas-liquid separation filter screen 21 is fixedly connected to the inner wall of the anode gas-liquid separation chamber 18;

The side walls of the cathode gas-liquid separation chamber 14 and the anode gas-liquid separation chamber 18 are respectively provided with drain pipes;

As shown in Figure 4, Figure 5, Figure 6 and Figure 7, the net surface of the buffer net 23 is corrugated, and the net surface of the buffer net 23 has a plurality of juxtaposed strip-shaped protrusions. There are at least three bending sections 25 , and adjacent bending sections 25 are connected by corresponding bending connecting parts 26 .

The anode 13 includes a metal substrate, and the surface of the metal substrate is coated with a metal oxide coating with catalytic function, and the metal oxide coating is composed of metal oxides of ruthenium, metal oxides of iridium, metal oxides of titanium and tin. In the metal oxide coating, according to the metal composition, the molar ratio of ruthenium element is 7%-15%, the molar ratio of iridium element is 1%-4.8%, and the molar ratio of titanium element is 1%-15%, the molar ratio of tin element is 75%-90%;

The anode 13 is made by the following steps:

A. Prepare the soluble inorganic salt of ruthenium element, the soluble inorganic salt of iridium element, the soluble inorganic salt of titanium element and the soluble divalent salt of tin element, and then separate the soluble inorganic salt of ruthenium element, the soluble inorganic salt of iridium element, the soluble inorganic salt of titanium element, The soluble inorganic salt of the element and the soluble divalent salt of the tin element are dissolved in water to obtain an aqueous solution of the soluble inorganic salt of the ruthenium element, the aqueous solution of the soluble inorganic salt of the iridium element, the aqueous solution of the soluble inorganic salt of the titanium element and the soluble divalent of the tin element. Aqueous solution of valence salt;

B. According to the molar ratio of ruthenium element is 7%-15%, the molar ratio of iridium element is 1%-4.8%, the molar ratio of titanium element is 1%-15%, and the molar ratio of tin element is 75%-90% The ratio of ruthenium soluble inorganic salt, the aqueous solution of the soluble inorganic salt of titanium element and the aqueous solution of the soluble divalent salt of tin element are mixed evenly, and then the aqueous solution of the soluble inorganic salt of iridium element is added and mixed evenly, to obtain an inorganic coating solution;

C. Clean the metal substrate, remove the surface dirt of the metal substrate, and make the surface of the metal substrate rough;

D. The inorganic coating solution obtained in step B is coated on the metal substrate processed in step C, and then the conductive substrate coated with the coating solution is heat treated in an oxygen-containing atmosphere, and the heat treatment temperature is 450 ℃-550 ℃ ℃, the heat treatment time is 30 minutes to 100 minutes, and a metal oxide coating is formed on the outer surface of the metal substrate, and then a layer of inorganic coating solution is coated again on the newly generated metal oxide coating, and then in The conductive substrate coated with the coating solution is heat treated in an oxygen-containing atmosphere. The heat treatment temperature is 450°C-550°C, and the heat treatment time is 30 minutes to 100 minutes. A new metal oxide coating is regenerated, and the cycle is repeated. The last heat treatment time is 60 minutes to 300 minutes, until the thickness of the metal oxide coating on the surface of the conductive substrate reaches the product requirements, and the anode 13 is obtained;

The soluble inorganic salt of ruthenium element is RuCl ₃ or RuN ₄ O ₁₀ , the soluble inorganic salt of iridium element is IrCl ₄ or Ir(NO ₃ ) ₄ , and the soluble inorganic salt of titanium element is TiCl ₄ or Ti(NO ₃ ) ₄ , the soluble divalent salt of tin element is SnCl ₂ ·2H ₂ O or Sn(NO ₃ ) ₂ ·20H ₂ O.

The anode 13 of the present invention is tested for weight loss of the metal oxide coating by immersing it in a 95° C., 32w% NaOH solution for 8 hours for enhanced electrolytic corrosion, and the life of the coating is evaluated. The results show that the life of the metal oxide coating of the present invention decreases. The weight (mg) is 2.9mg-3.3mg, while the life-time weight loss (mg) of the existing metal oxide coating is usually 4.0mg-6.0mg, which shows that the life-time weight loss of the anode 13 of the present invention is optimized, and the The content of the precious metals Ru and Ir in the surface coating of the anode 13 is significantly reduced, and the electrode manufacturing cost is also significantly reduced.

The anode 13 of the present invention, under the electrolysis condition in 90 ℃, 3.5mol/L NaCl solution, test 4KA/m Under the current density, the electrode chlorine evolution overpotential is 33.7mV-40.4mV, and in the prior art 4KA/m Current density The chlorine evolution overpotential of the lower electrode is usually above 60mV, which shows that the anode of the present invention has excellent operating performance under high current density, effectively reduces the chlorine evolution overpotential of the electrode, and has a remarkable energy saving effect.

The preparation process of the anode 13 of the present invention all uses inorganic compounds, does not use any organic solvent, and the coating production process is very simple, thereby reducing the difficulty and cost of electrode production, and also avoiding the organic solvent. an adverse effect.

The preparation method of the anode 13 of the present invention uses an appropriate proportion of divalent tin in the preparation of the coating solution, thereby realizing that the electrode surface coating particles can be refined without adding expensive platinum, palladium and other elements, and the At the same time, the catalytic activity of the electrode is improved, thereby reducing the energy consumption of the chlor-alkali electrolysis and controlling the cost of the electrode.

Different from tetravalent tin, the deposition amount of Sn in the electrode coating made of the coating solution composed of divalent tin is higher than 70% and can be stably controlled, while tetravalent tin has high volatility during high temperature oxidation, resulting in tin in The deposition in the coating is less than 30% and the composition is not controllable. At the same time, since divalent tin easily undergoes redox reactions with other elements in the coating solution and forms complexes, the oxides obtained during thermal oxidation are more uniformly distributed, more tightly bound, and the size of metal oxide particles is significantly refined, It is helpful to prolong the service life of the anode 13 and reduce the chlorine evolution potential of the electrode. At the same time, the inorganic salt of divalent tin is easy to obtain in the market, has low price and can be directly used in the preparation of coating liquid, which not only simplifies the coating production process, but also reduces the cost of raw materials.

Example 1

The preparation method of the anode 13 of the present invention is as follows:

(1) Roughening and cleaning of the metal matrix: The metal matrix is made of TA1 mesh titanium plate with a mesh size of 6mm*3mm*1mm. After leveling the mesh titanium plate, use a weight percent concentration of 20 -25% sulfuric acid is heated to boiling and pickled for 1-4 hours to remove surface dirt and roughen the surface of the metal substrate. After pickling, rinse with pure water and dry for later use.

(2) Coating solution preparation: molar ratios of the elements Ru7%, Ir1%, Ti2% , Sn90% inorganic coating solution preparation, specifically in a cold bath at -20 ℃ below will join with 0.1mlTiCl ₄ container 1.8mlRuCl ₃ aqueous hydrochloric acid, was allowed to stand to room temperature, the vessel was again 8ml dilute aqueous hydrochloric acid, was added to the vessel again 6.222gSnCl _₂ · 2H ₂ O inorganic salt, stirring SnCl _₂ · 2H ₂ O completely inorganic dissolved, 0.5mlIrCl ₄ aqueous hydrochloric acid was added to the vessel and stirred uniformly, added 18ml of dilute aqueous hydrochloric acid and finally into the vessel, after placing the volume to 30ml shake for 30 minutes no precipitation was observed coating liquid can be used.

(3) Preparation of electrode coating: apply the coating solution prepared in step (2) on the metal substrate treated in step (1), heat treatment at 450°C for 30 min; then repeat the coating solution 10 times, each time After coating the coating solution, heat treatment at 450 °C for 30 min, and after coating the final layer with the coating solution, heat treatment at 500 °C for 120 min.

Example 2

The preparation method of the anode 13 of the present invention is as follows:

1) Roughening and cleaning of the metal matrix: The metal matrix is made of TA1 mesh titanium plate with a mesh size of 6mm*3mm*1mm. After leveling the mesh titanium plate, use a weight percent concentration of 20- After 25% sulfuric acid is heated to boiling, pickle the mesh titanium plate for 2-3 hours to remove the surface dirt and roughen the surface of the metal substrate. After the pickling is completed, rinse it with pure water and dry it for later use.

2) Preparation of coating solution: prepare an inorganic coating solution according to the molar ratios of Ru15%, Ir1%, Ti2% and Sn82%. Under the condition of a cold bath below -20°C, add 0.1ml TiCl ₄ to 3.9ml RuCl ₃ aqueous hydrochloric acid in the vessel was allowed to stand to room temperature, was added to the vessel 8ml dilute aqueous hydrochloric acid, was added to the vessel again 5.864gSnCl _₂ · 2H ₂ O inorganic salt, stirring SnCl _₂ · 2H ₂ O was completely dissolved inorganic salts, and then Add 0.5ml of IrCl ₄ hydrochloric acid aqueous solution to the container and stir evenly. Finally, add 16ml of dilute hydrochloric acid aqueous solution to the container, set the volume to 30ml, shake well and place for 30 minutes. Observe that the coating solution has no precipitation and can be used.

3) Electrode coating preparation: apply the coating solution prepared in step 2) on the metal substrate treated in step 1), heat treatment at 450 ° C for 30 min, repeat the coating solution and heat treatment 8 times, from the second coating At the beginning of the coating solution, heat treatment at 500 °C for 60 min each time, and after the final layer is coated with the coating solution, heat treatment at 530 °C for 300 min.

Example 3

The preparation method of the anode 13 of the present invention is as follows:

1) Roughening and cleaning of the metal matrix: The metal matrix is made of TA1 mesh titanium plate with a mesh size of 6mm*3mm*1mm. After leveling the mesh titanium plate, use a weight percent concentration of 20- After 25% sulfuric acid is heated to boiling, pickling the mesh titanium plate for 3-4 hours to remove the surface dirt and roughen the surface of the metal substrate. After the pickling, rinse with pure water and dry it for later use.

2) Preparation of coating solution: prepare an inorganic coating solution according to the molar ratios of Ru10%, Ir3%, Ti2% and Sn85%, and under the condition of a cold bath below -20°C, add 0.1ml TiCl4 to an aqueous hydrochloric acid solution containing 2.6ml RuCl3 After being placed in the container of normal temperature, add 8ml of dilute hydrochloric acid aqueous solution to the container, add 6.079g SnCl2 2H2O inorganic salt to the container, stir to make SnCl2 2H2O inorganic salt completely dissolve, then add 1.5ml IrCl4 hydrochloric acid aqueous solution to the container and stir well , and finally add 16ml of dilute hydrochloric acid aqueous solution to the container to make the volume to 30ml, shake well, and leave it for 30 minutes, and observe that the coating solution can be used without precipitation.

3) Electrode coating preparation: apply the coating solution prepared in step 2) on the metal substrate treated in step 1), heat treatment at 450 ° C for 30 min, repeat the coating solution and heat treatment 9 times, from the second coating The coating solution was started, and each heat treatment was performed at 485 °C for 30 min. After the final layer was coated with the coating solution, the heat treatment was performed at 530 °C for 180 min.

Example 4

The preparation method of the anode 13 of the present invention is as follows:

2) Preparation of coating solution: prepare an inorganic coating solution according to the molar ratios of Ru10%, Ir3%, Ti2%, Sn85%, and add 0.182g Ti(NO ₃ ) ₄ In a container with 3.1ml RuN4O10 acidic aqueous solution, add a small amount of dilute nitric acid aqueous solution to the container and stir to completely dissolve Ti(NO3)4. After placing it at room temperature, add 15.722g Sn(NO3)2·20H2O inorganic salt to the container, and stir to make Sn (NO ₃ ) ₂ ·20H ₂ O inorganic salt was completely dissolved, then 1.8ml of Ir(NO3)4 acid aqueous solution was added and stirred evenly. Finally, 13ml of dilute nitric acid aqueous solution was added to the container and the volume was adjusted to 30ml. The liquid can be used without precipitation.

3) Electrode coating preparation: apply the coating solution prepared in step 2) on the metal substrate treated in step 1), heat treatment at 450°C for 30 min, repeat the coating solution and heat treatment 9 times, starting from the second time , heat treatment at 485 °C for 30 min each time, and heat treatment at 530 °C for 180 min after the final layer is coated with the coating solution.

As a further improvement of the present invention, the angle a between the above-mentioned adjacent bending segments 25 is not less than 90°, and the corrugated shape of the mesh surface can be a wavy line as shown in FIG. 8 , or it can be as shown in FIG. 9 . In the undulating line shown, the included angle a between adjacent bending segments 25 cannot be 180° without bending.

As a further improvement of the present invention, the top of the above-mentioned cathode chamber guide plate 10 is connected to the top of the cathode chamber 5, the top of the anode chamber guide plate 11 is connected to the top of the anode chamber 4, and each of the protrusions has 4- There are 10 bending sections 25, the corrugated shape of the mesh surface is wavy line shape or undulating line shape, and the included angle a between the adjacent bending sections 25 is 110°-160°.

As a further improvement of the present invention, the above-mentioned buffer net 23 is formed by stacking and adhering the net surfaces of the multi-layer metal nets, that is, the net can be a single-layer net, a double-layer net or a multi-layer structure net. The included angle a between the adjacent bending sections 25 is 120°-150°.

The above-mentioned nets can be laid in a single layer or in two or more layers when in use. For electrolyzers with different electrode spacing and different requirements, different layers of buffer nets can be used. In order to ensure a small pressing force on the film, a single-layer buffer net can be used to lay one layer, and simple homogenization treatment is performed after assembly, which greatly ensures the initial support force of the buffer net and reduces the pressing force on the film. . If better resilience and support performance are required, two or more layers of buffer nets can be selected accordingly, preferably the fold lines of the adjacent layers are distributed in opposite directions. The structure makes the cushioning and supporting performance of the cushioning net better.

As a further improvement of the present invention, as shown in FIG. 8 or FIG. 9 , the height X of the raised portion of the buffer net 23 is 2-10 mm, and the included angle a between the adjacent bending sections 25 is 130° -150°.

As a further improvement of the present invention, the number of the above-mentioned metal mesh is 2-4 layers, the diameter of the metal wire used for the woven metal mesh is 0.1-0.6 mm, the cathode 12 is made of metal nickel, and the anode 13 is made of metal titanium .

It doesn't matter if the buffer net is a single-layer setup, or a double-layer or 3-layer or 4-layer setup. The height of the buffer net is preferably 2-10 mm, and the diameter of the wire used for weaving the buffer net is preferably 0.1-0.6 mm.

As a further improvement of the present invention, the above-mentioned bending connecting portion 26 is arc-shaped. The curved connecting portion 26 is arranged in an arc structure, which effectively slows down the effect of the pressure on the inflection point during operation, so that the service life of the buffer net is longer and the performance is better. The specific laying layers and height are determined according to the actual use requirements. If a single layer is provided with a buffer net, the height of the single layer can be changed accordingly. If there are two or more layers, the height of the single-layer buffer net can be reduced, and the thickness of the buffer net can be adjusted after assembly to ensure that the thickness of the buffer net does not affect the extrusion force of the film and can achieve a very high rebound. The rebound range needs to be higher than the pole spacing after extrusion.

As a further improvement of the present invention, the porosity of the cathode 12 and the anode 13 are respectively 30%-60%; the aperture of the liquid inlet hole 9 of the anode chamber is 1mm-3mm, and the aperture of the liquid inlet hole 7 of the cathode chamber is 1mm-3mm ; The thickness of the anode 13 is 1mm-1.5mm.

The included angle a at the fold point of each single broken line of the buffer net of the present invention is 90°<a<180°. The larger the angle a, the smaller the deformation of the buffer net in the longitudinal direction, but the ability to maintain the shape of the buffer net will be weaker, that is, the resilience will be weakened. The smaller the included angle a, the higher the strength of the buffer net in the short side direction, the stronger the ability to maintain the shape of the buffer net, but the greater the deformation in the long side direction and the more difficult the processing. Therefore, it is preferable that the included angle a is 90°<a<180°.

When the buffer net in the membrane electrode distance sub-membrane electrolytic cell of the present invention is in use, as shown in FIG. The structure of the dots can maintain the elastic effect of the buffer net to the maximum extent, and avoid the release of the force generated by the buffer net along the long side of the net and more along the long side of the net under the state of plane compression. Displacement deformation occurs, causing the structure of the net to deform asymmetrically and disproportionately, affecting the elasticity of the buffer net. Since the structure of the plurality of bending segments 25 is in the state of plane compression, displacement and deformation will occur along the directions of different bending segments 25, and the forces and deformations released in the opposite direction to the adjacent bending segments 25 will be generated. The effect of the buffer net makes the force of the buffer net more uniform, and it also makes the buffer net have a good rebound effect after being stressed. Therefore, the buffer net for the membrane electrode distance sub-membrane electrolytic cell of the present invention can effectively protect the ion membrane, so that the ion membrane is more uniformly stressed, and at the same time, the buffer net has a good rebound effect after being stressed, which is very good. It ensures the gap between the cathode and anode, which can improve the service life of the ion membrane while ensuring the conductivity and elastic effect.

In the present invention, the membrane electrode is far from the sub-membrane electrolysis cell, and the bottom of the cathode chamber 5 is provided with a row of cathode chamber liquid inlet holes 7 along the front and rear directions. The channels 8 communicate with each other, the cathode chamber 5 is provided with a cathode chamber guide plate 10, the plate surface of the cathode chamber guide plate 10 is located in the front and rear direction, the cathode chamber guide plate 10 is inclined and the top of the cathode chamber guide plate 10 is connected to the cathode. The horizontal distance between 12 is less than the horizontal distance between the bottom end of the cathode chamber guide plate 10 and the cathode 12; and the bottom of the anode chamber 4 is provided with a row of anode chamber liquid inlet holes 9 along the front and rear directions, and the anode chamber liquid inlet holes 9 communicates with the anode chamber liquid inlet channel 22 located below the anode chamber 4 in the frame 1. The anode chamber 4 is provided with an anode chamber guide plate 11, and the plate surface of the anode chamber guide plate 11 is located in the front and rear direction, and the anode chamber guide plate 11 is inclined, and the horizontal distance between the top end of the anode chamber guide plate 11 and the anode 13 is smaller than the horizontal distance between the bottom end of the anode chamber guide plate 11 and the anode 13; When it is in the chamber, it can fully participate in the electrolysis and lead out with the generated products, avoiding the formation of a dead zone with poor liquid fluidity.

The distance between the membrane electrode and the sub-membrane electrolytic cell of the present invention can allow the reacted electrolyte to flow back to the cathode chamber liquid inlet hole 7 below the cathode chamber 5, and fully mix with the electrolyte solution from each cathode chamber liquid inlet hole 7, thereby reducing the reduction of the cathode chamber. The concentration of the electrolyte in the chamber 5 is different, and at the same time, the reacted electrolyte can be returned to the anode chamber inlet hole 9 below the anode chamber 4, and the electrolyte from each cathode chamber inlet hole 7 can be fully mixed, reducing the anode chamber. The concentration of the electrolyte in the chamber 4 is different. By introducing the reacted electrode solution into the bottom inlet of the electrolysis chamber to mix with the electrolyte that has not reacted or rarely reacted, the concentration difference between the bottom and the top of the electrolysis chamber is reduced, which is more conducive to balancing the ion concentration of the electrolyte in the electrolysis chamber, and also It is more conducive to effectively conduct the reaction heat and reduce the temperature difference in the electrolysis chamber.

The above-mentioned embodiments are only to describe the preferred embodiments of the present invention, and do not limit the scope of the present invention. On the premise of not departing from the design spirit of the present invention, various modifications made by ordinary engineers and technicians in the art to the technical solutions of the present invention and improvements, all should fall within the protection scope determined by the claims of the present invention.

Claims

The membrane electrode distance sub-membrane electrolytic cell is characterized in that it comprises a plurality of frames (1) arranged in parallel, the frame surfaces of the plurality of frames (1) are located in the front and rear vertical directions, and the frame surfaces of the adjacent frames (1) are arranged in close contact with each other , between the frame surfaces of adjacent frames (1), a sealing member (2) for sealing the gap between the mating surfaces of the frames (1) is provided;

One side of the frame (1) is provided with a cathode chamber (5), the other side is provided with an anode chamber (4), and a conductive composite plate ( 3), the cathode compartment (5) and the anode compartment (4) on the multiple frames (1) are arranged according to one cathode compartment (5), one anode compartment (4), another cathode compartment (5), and another anode compartment ( 4) The sequence is set at intervals from each other;

The cathode chamber (5) of each frame (1) and the anode chamber (4) of an adjacent frame (1) respectively form a membrane distance sub-membrane electrolytic cell unit, and each membrane pole distance sub-membrane electrolytic cell unit An ion exchange membrane (6) for separating the membrane pole from the cathode compartment (5) of the sub-membrane electrolytic cell unit and the anode compartment (4) is provided inside, and the ion exchange membrane (6) is located in the front and rear vertical directions. ;

The bottom of the cathode chamber (5) is provided with a row of cathode chamber liquid inlet holes (7) along the front and rear directions, and the cathode chamber liquid inlet holes (7) enter into the cathode chamber located below the cathode chamber (5) in the frame (1). The liquid channels (8) communicate with each other, the cathode chamber (5) is provided with a cathode chamber guide plate (10), the plate surface of the cathode chamber guide plate (10) is located in the front-rear direction, and the cathode chamber guide plate (10) is arranged in an inclined manner , the horizontal distance between the top end of the cathode chamber guide plate (10) and the cathode (12) is smaller than the horizontal distance between the bottom end of the cathode chamber guide plate (10) and the cathode (12);

The bottom of the anode chamber (4) is provided with a row of anode chamber liquid inlet holes (9) along the front-rear direction, and the anode chamber liquid inlet holes (9) enter into the anode chamber located below the anode chamber (4) in the frame (1). The liquid channels (22) communicate with each other, the anode chamber (4) is provided with an anode chamber guide plate (11), the plate surface of the anode chamber guide plate (11) is located in the front-rear direction, and the anode chamber guide plate (11) is inclined and arranged , the horizontal distance between the top of the anode chamber guide plate (11) and the anode (13) is smaller than the horizontal distance between the bottom end of the anode chamber guide plate (11) and the anode (13);

In the cathode chamber (5) of each membrane electrode distance sub-membrane electrolysis cell unit, a cathode (12) is installed at the end of the cathode chamber (5) where the ion exchange membrane (6) is arranged, and the plate surface of the cathode (12) Located in the front and rear vertical directions; one surface of the cathode (12) is attached to one surface of the corresponding ion exchange membrane (6), and the other surface of the cathode (12) is attached to the mesh surface of a buffer net (23), and the buffer net The other mesh surface of (23) is attached to a surface of the cathode bottom mesh (24), and the cathode bottom mesh (24) is fixed in the cathode chamber (5);

In the anode chamber (4) of each membrane-electrode distance sub-membrane electrolytic cell unit, an anode (13) is installed at the end of the anode chamber (4) where the ion exchange membrane (6) is arranged, and the plate surface of the anode (13) in the front and rear vertical direction;

In the frame (1), a cathode gas-liquid separation chamber (14) is arranged above the cathode chamber (5), and the cathode (14) of the cathode gas-liquid separation chamber (14) is close to the bottom of the cathode gas-liquid separation chamber (14). 12) is provided with an elongated cathode gas-liquid separation chamber liquid inlet (15) on one side, and is close to the composite plate (3) of the cathode gas-liquid separation chamber (14) at the bottom of the cathode gas-liquid separation chamber (14). There is a cathode gas-liquid separation chamber return port (16) on one side, and a cathode gas-liquid separation filter screen (17) for breaking foam is arranged in the cathode gas-liquid separation chamber (14) along the front and rear directions, and the cathode gas-liquid separation filter screen (17). The edge of (17) is fixedly connected with the inner wall of the cathode gas-liquid separation chamber (14);

An anode gas-liquid separation chamber (18) is provided in the frame (1) above the anode chamber (4), and an anode (13) of the anode gas-liquid separation chamber (18) is located at the bottom of the anode gas-liquid separation chamber (18) close to the anode chamber (18). ) is provided with an elongated anode gas-liquid separation chamber liquid inlet (19), and the bottom of the anode gas-liquid separation chamber (18) is close to the side of the composite plate (3) of the anode gas-liquid separation chamber (18). An anode gas-liquid separation chamber return port (20) is provided, an anode gas-liquid separation filter screen (21) for breaking foam is arranged in the cathode gas-liquid separation chamber (14) along the front and rear directions, and an anode gas-liquid separation filter screen (21) The edge of the anodic gas-liquid separation chamber (18) is fixedly connected to the inner wall;

Drain pipes are respectively provided on the side walls of the cathode gas-liquid separation chamber (14) and the anode gas-liquid separation chamber (18);

The net surface of the buffer net (23) is in a corrugated shape, and the net surface of the buffer net (23) has a plurality of bar-shaped protrusions arranged in parallel, and the protrusions have at least three bending sections (25) , the adjacent bending segments (25) are connected by corresponding bending connecting parts (26);

The anode (13) comprises a metal substrate, and the surface of the metal substrate is coated with a metal oxide coating having a catalytic effect, and the metal oxide coating is composed of metal oxides of ruthenium, metal oxides of iridium, and metal oxides of titanium. and tin metal oxide, the metal oxide coating is based on the metal composition, wherein the molar ratio of ruthenium element is 7%-15%, the molar ratio of iridium element is 1%-4.8%, and the molar ratio of titanium element is 1%-4.8%. The ratio is 1%-15%, and the molar ratio of tin element is 75%-90%.
The membrane electrode distance sub-membrane electrolytic cell according to claim 1, characterized in that the included angle a between the adjacent bending sections (25) is not less than 90°.
The membrane-electrode distance sub-membrane electrolytic cell according to claim 2, characterized in that: the top of the cathode chamber guide plate (10) is connected to the top of the cathode chamber (5), and the anode chamber guide plate (11) is connected to the top of the cathode chamber (5). The top end is connected to the top of the anode chamber (4), each of the protruding parts has 4-10 bending sections (25), the corrugated shape of the mesh surface is wavy or undulating, and the adjacent curved The included angle a between the folded sections (25) is 110°-160°.
The membrane electrode distance sub-membrane electrolytic cell according to claim 3, characterized in that: the buffer net (23) is formed by superimposing the net surfaces of the multi-layer metal nets, and the adjacent bending sections (25) The included angle a between them is 120°-150°.
The membrane electrode distance sub-membrane electrolytic cell according to claim 4, characterized in that: the height of the raised portion of the buffer net (23) is 2-10 mm, and the height between the adjacent bending sections (25) is 2-10 mm. The included angle a is 130°-150°.
The membrane electrode distance sub-membrane electrolytic cell according to claim 5, wherein the number of the metal mesh is 2-4 layers, the diameter of the metal wire used for the woven metal mesh is 0.1-0.6 mm, and the The cathode (12) is made of metallic nickel, and the anode (13) is made of metallic titanium.
The membrane electrode distance sub-membrane electrolytic cell according to claim 6, characterized in that: the bending connection portion (26) is arc-shaped.
The membrane-electrode distance sub-membrane electrolytic cell according to claim 7, characterized in that the porosity of the cathode (12) and the anode (13) are respectively 30%-60%; The aperture is 1mm-3mm, the aperture of the liquid inlet hole (7) of the cathode chamber is 1mm-3mm; the thickness of the anode (13) is 1mm-1.5mm.