Anti-corrosion nitrogen trifluoride electrolytic bath

Abstract

The anti-corrosion nitrogen trifluoride electrolytic cell comprises a cell body, the cell body is made of carbon steel and comprises a containing cavity and a top opening, and the outer wall of the cell body is electrically connected with the negative electrode of an external power source; the sealing cover is used for sealing the top opening; the anode binding post penetrates through the sealing cover and is used for being electrically connected with an anode of an external power supply; the cathode binding post is arranged on the sealing cover in a penetrating manner and is electrically connected with the outer wall of the tank body; the cathode plate is arranged in the accommodating cavity, is fixed on the cathode binding post and is electrically connected with the inner wall of the tank body; the anode plate is arranged in the accommodating cavity and is fixed on the anode binding post; and the cooling jacket is arranged at the top of the sealing cover and used for cooling the sealing cover, and the temperature of the cooling jacket is smaller than the melting point temperature of electrolyte in the electrolyte. According to the invention, the tank body is connected in series into a circuit to become a negative electricity carrier to continuously supplement electrons so as to avoid corrosion, and in addition, the cooling jacket is arranged to prevent local corrosion current from being formed and avoid corrosion to the sealing cover.

Description

Technical Field

[0001] The utility model relates to the technical field of electrolytic cell equipment, in particular to an anti-corrosion nitrogen trifluoride electrolytic cell. Background Art

[0002] Nitrogen trifluoride is widely used in the electronics industry in circuit board etching, LCD etching and cleaning, chip manufacturing, high-energy lasers and other fields. It is favored for its excellent etching rate, selectivity and no residual substances. As a key equipment for the preparation of nitrogen trifluoride, the performance of the nitrogen trifluoride electrolytic cell directly affects the product quality, yield and power consumption of the preparation process.

[0003] A typical nitrogen trifluoride electrolytic cell consists of a cell body, an anode and a cathode, and most of them use a diaphragm to separate the anode chamber and the cathode chamber. When direct current passes through the electrolytic cell, an oxidation reaction occurs at the interface between the anode and the solution, and a reduction reaction occurs at the interface between the cathode and the solution to produce the desired product.

[0004] However, nitrogen trifluoride is highly oxidizing and can react with a variety of substances, including metals and non-metals. When nitrogen trifluoride contacts the inner wall of the electrolytic cell, it is easy to corrode the inner wall of the cell. In addition, the cathode gas collection chamber and the anode gas collection chamber of the nitrogen trifluoride electrolytic cell are usually designed to be separated, resulting in an uneven potential difference in each part. After the electrolyte evaporates, it condenses at the sealing cover above the anode at a slightly lower temperature to form an electrolyte liquid film. Due to the potential difference, the metal ions of the sealing cover above the anode lose electrons and enter the liquid film, thereby forming a local corrosion current, which in turn affects the corrosion resistance of the sealing cover.

[0005] In the prior art, this problem is usually solved by lining the inner wall of the tank body and the inner surface of the sealing cover with a nickel plate or a PFA coating, but these methods increase the preparation cost. In addition, the heat transfer structure design of the electrolytic cell lined with the PFA coating is complicated and the heat transfer effect is poor, resulting in bulky equipment and low output per unit area. Utility Model Content

[0006] The utility model aims to provide a corrosion-resistant nitrogen trifluoride electrolytic cell to solve the problems in the prior art that the inner wall of the electrolytic cell is easily corroded by nitrogen trifluoride, and that local corrosion current is easily generated in the electrolytic cell, affecting the corrosion resistance of the sealing cover. The electrolytic cell circuit itself is used to make the entire cell body a reaction cathode, and a cooling jacket is provided to cool the sealing cover, so that the volatilized electrolyte solidifies into a solid, avoiding the formation of local corrosion current, thereby improving the corrosion resistance of the electrolytic cell and reducing the preparation cost of the electrolytic cell.

[0007] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0008] A corrosion-resistant nitrogen trifluoride electrolytic cell, comprising:

[0009] A tank body, made of carbon steel, used to contain electrolyte, the tank body comprising a containing cavity and a top opening, and an outer wall of the tank body being electrically connected to a negative electrode of an external power source;

[0010] A sealing cover, used for closing the top opening;

[0011] an anode terminal, which is disposed on the sealing cover and is used for being electrically connected to the positive electrode of the external power source;

[0012] A cathode terminal, which is passed through the sealing cover and electrically connected to the outer wall of the tank body;

[0013] A cathode plate is disposed in the accommodating cavity, the cathode plate is fixed on the cathode terminal and is electrically connected to the inner wall of the tank body;

[0014] an anode plate, disposed in the accommodating cavity and fixed on the anode terminal;

[0015] A cooling jacket is arranged on the top of the sealing cover and is used to cool the sealing cover. The temperature of the cooling jacket is lower than the melting point of the electrolyte in the electrolyte.

[0016] In some embodiments, the distance between the edge of the anode plate and the inner wall of the tank body is 135 mm to 145 mm.

[0017] In some embodiments, an insulating sleeve is provided at the edge of the anode plate.

[0018] In some embodiments, a plurality of connecting copper plates are provided on the outer wall of the tank body, and the tank body is electrically connected to the negative electrode of the external power source and the cathode terminal respectively through the connecting copper plates.

[0019] In some embodiments, the connecting copper plate is connected to the tank body by welding.

[0020] In some embodiments, an insulating cone sleeve is provided between the sealing cover and the anode terminal, and between the sealing cover and the cathode terminal.

[0021] Due to the application of the above technical solution, the beneficial effects of the present application compared with the prior art are:

[0022] The present application utilizes the original connection circuit between the electrolytic cell and the external power supply, electrically connects the cathode plate to the cell body, connects the cell body in series to the circuit, and uses the cell body as the negative electrode to ensure that during the electrolysis process the cell body and the cathode plate can continuously provide electrons to the positive ions in the electrolyte, which are then transmitted to the anode plate. This design ensures that the cell body continuously replenishes electrons, effectively preventing the metallic iron in the cell body from losing electrons and becoming divalent iron ions and dissolving into the electrolyte, thereby reducing corrosion to the cell body.

[0023] In addition, a cooling jacket is provided on the top of the sealing cover, and its temperature is lower than the melting point of the electrolyte in the electrolyte. During the electrolysis process, the cooling jacket allows the electrolyte volatilized onto the sealing cover to quickly solidify into a non-conductive solid, effectively preventing the formation of local corrosion current and avoiding corrosion to the sealing cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a schematic diagram of the circuit connection between the anti-corrosion nitrogen trifluoride electrolytic cell and the external power supply in one embodiment of the utility model;

[0026] Figure 2 It is a schematic cross-sectional view of the structure of an anti-corrosion nitrogen trifluoride electrolytic cell in one embodiment of the utility model;

[0027] Figure 3 Schematic diagram of the distribution of some electric lines between the edge of the anode plate and the inner wall of the tank body in one embodiment of the utility model.

[0028] Description of reference numerals:

[0029] 1-tank body; 2-sealing cover; 3-anode terminal; 4-cathode terminal; 5-anode plate; 6-cathode plate; 7-insulating cone sleeve; 8-electrolyte; 10-electrolyzer; 20-external power supply; 30-cooling jacket; 40-power line. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0031] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0032] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0033] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0034] In addition, the terms "installed", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0035] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0036] See also Figure 1 and Figure 2 The corrosion-resistant nitrogen trifluoride electrolytic cell of one embodiment of the present application includes a cell body 1, a sealing cover 2, an anode terminal post 3, a cathode terminal post 4, a cathode plate 6, an anode plate 5 and a cooling jacket 30.

[0037] Specifically, the tank body 1 is made of carbon steel and is used to contain the electrolyte 8. The tank body 1 includes a containing cavity and a top opening. The outer wall of the tank body 1 is electrically connected to the negative electrode of the external power source 20. The sealing cover 2 is used to close the top opening.

[0038] The anode terminal 3 is provided on the sealing cover 2 and is used to be electrically connected to the positive electrode of the external power source 20. The cathode terminal 4 is provided on the sealing cover 2 and is electrically connected to the outer wall of the tank body 1.

[0039] The cathode plate 6 is disposed in the accommodating cavity, fixed on the cathode terminal 4 , and electrically connected to the inner wall of the tank body 1 .

[0040] The anode plate 5 is arranged in the accommodating cavity and fixed on the anode terminal 3 .

[0041] It is worth noting that the current of the electrolytic cell 10 during electrolysis is generally about 10000A. The cell body 1 is set to carbon steel material, and there is a different potential difference between the cell body 1 and the anode plate 5, especially between the edge of the anode plate 5 and the cell body 1 perpendicular to it. The potential difference is particularly obvious, such as Figure 3 As shown, the electric field lines 40 are dense at the edge of the anode plate 5, which makes it easy for the tank body 1 near the edge of the anode plate 5 to be corroded. For this reason, in the present application, the edge of the anode plate 5 is insulated and sealed, and the distance between the edge of the anode plate 5 and the inner wall of the tank body 1 is increased to avoid the above situation.

[0042] In some embodiments, an insulating sleeve (not shown) is disposed at the edge of the anode plate 5 .

[0043] In some embodiments, the distance between the edge of the anode plate 5 and the inner wall of the tank body 1 is 135 mm to 145 mm.

[0044] The cooling jacket 30 is arranged on the top of the sealing cover 2 for cooling the sealing cover 2. The temperature of the cooling jacket 30 is lower than the melting point of the electrolyte in the electrolyte 8. The cooling jacket 30 is a conventional structure and will not be described in detail here. Specifically, the temperature of the cooling jacket 30 can be set to be less than 70°C. This application does not make any specific limitation on this.

[0045] In some embodiments, a plurality of connecting copper plates (not shown) are disposed on the outer wall of the tank body 1, and the tank body 1 is electrically connected to the negative electrode and the cathode terminal 4 of the external power source 20 through the connecting copper plates. Specifically, the connecting copper plates are connected to the tank body 1 by welding.

[0046] In some embodiments, an insulating cone sleeve 7 is provided between the sealing cover 2 and the anode terminal 3, and between the sealing cover 2 and the cathode terminal 4. This is a conventional structure and will not be described in detail here.

[0047] Due to the application of the above technical solution, the beneficial effects of the present application compared with the prior art are:

[0048] The present application utilizes the original connection circuit between the electrolytic cell and the external power supply, electrically connects the cathode plate to the cell body, connects the cell body in series to the circuit, and uses the cell body as the negative electrode to ensure that during the electrolysis process the cell body and the cathode plate can continuously provide electrons to the positive ions in the electrolyte, which are then transmitted to the anode plate. This design ensures that the cell body continuously replenishes electrons, effectively preventing the metallic iron in the cell body from losing electrons and becoming divalent iron ions and dissolving into the electrolyte, thereby reducing corrosion to the cell body.

[0049] In addition, a cooling jacket is provided on the top of the sealing cover, and its temperature is lower than the melting point of the electrolyte in the electrolyte. During the electrolysis process, the cooling jacket allows the electrolyte volatilized onto the sealing cover to quickly solidify into a non-conductive solid, effectively preventing the formation of local corrosion current and avoiding corrosion to the sealing cover.

[0050] Finally, it should be noted that the above are only preferred embodiments of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A corrosion-resistant nitrogen trifluoride electrolytic cell, characterized in that: include: A tank body, made of carbon steel, used to contain electrolyte, the tank body comprising a containing cavity and a top opening, and an outer wall of the tank body being electrically connected to a negative electrode of an external power source; A sealing cover, used for closing the top opening; an anode terminal, which is disposed on the sealing cover and is used for being electrically connected to the positive electrode of the external power source; A cathode terminal, which is passed through the sealing cover and electrically connected to the outer wall of the tank body; A cathode plate is disposed in the accommodating cavity, the cathode plate is fixed on the cathode terminal and is electrically connected to the inner wall of the tank body; an anode plate, disposed in the accommodating cavity and fixed on the anode terminal; A cooling jacket is arranged on the top of the sealing cover and is used to cool the sealing cover. The temperature of the cooling jacket is lower than the melting point of the electrolyte in the electrolyte.

2. The corrosion-resistant nitrogen trifluoride electrolytic cell according to claim 1, characterized in that: The distance between the edge of the anode plate and the inner wall of the tank body is 135 mm to 145 mm.

3. The corrosion-resistant nitrogen trifluoride electrolytic cell according to claim 1, characterized in that: An insulating sleeve is arranged at the edge of the anode plate.

4. The corrosion-resistant nitrogen trifluoride electrolytic cell according to claim 1, characterized in that: A plurality of connecting copper plates are arranged on the outer wall of the tank body, and the tank body is electrically connected to the negative electrode of the external power source and the cathode terminal respectively through the connecting copper plates.

5. The corrosion-resistant nitrogen trifluoride electrolytic cell according to claim 4, characterized in that: The connecting copper plate is connected to the tank body by welding.

6. The corrosion-resistant nitrogen trifluoride electrolytic cell according to claim 1, characterized in that: An insulating cone sleeve is arranged between the sealing cover and the anode terminal, and between the sealing cover and the cathode terminal.

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