Aluminum electrolytic cell anode voltage drop testing device

Abstract

This application discloses an anode voltage drop testing device for an aluminum electrolytic cell, comprising an electromagnetic shielding box, a millivoltmeter, a positive test rod, and a negative test rod. The millivoltmeter is placed inside the electromagnetic shielding box. One end of the positive test rod is connected to the millivoltmeter via a wire, and the other end is connected to the anode steel claw. One end of the negative test rod is connected to the millivoltmeter via a wire, and the other end is connected to a reinforcing bar on the anode carbon block. The electromagnetic shielding box includes a box body and an observation window. The box body has an observation opening, and the observation window is located at the observation opening. The observation window includes a first glass layer and a metal mesh, with the metal mesh embedded within the first glass layer. The first glass layer includes glass and a conductive film, with the conductive film formed on the surface of the glass facing the outside of the box body. This voltage drop testing device places the millivoltmeter inside the electromagnetic shielding box, and the observation window is equipped with a first glass layer and a metal mesh embedded within it. A conductive film is also provided on the surface of the first glass layer, achieving full-band electromagnetic protection and avoiding inaccurate readings caused by magnetization.

Description

Technical Field

[0001] This application relates to the field of aluminum electrolytic cell voltage drop testing technology, and in particular to an aluminum electrolytic cell anode voltage drop testing device. Background Technology

[0002] The anode is an important component of the aluminum electrolytic cell. Currently, the commonly used anode structure of aluminum electrolytic cells is made by casting and bonding the anode steel claws and anode carbon blocks with pig iron. The iron-carbon contact voltage drop of the cast part is an important component of the anode voltage drop, accounting for 1 / 3 to 1 / 2 of the total anode voltage drop. Therefore, accurately measuring the iron-carbon voltage drop of the anode is of great significance for understanding the voltage composition of the electrolytic cell.

[0003] During the aluminum electrolysis production process, the surface of the steel claws is prone to oxidation, forming an oxide film. The strong magnetization environment can easily lead to problems such as magnetization of the wires and magnetization of the voltmeter pointer, resulting in inaccurate readings and inaccurate measurement of the anode iron-carbon voltage drop. Utility Model Content

[0004] This invention provides an anode voltage drop testing device for aluminum electrolysis cells to solve the technical problem of inaccurate anode iron-carbon voltage drop measurement in the prior art.

[0005] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0006] In a first aspect, this utility model provides an anode voltage drop testing device for an aluminum electrolytic cell, comprising an electromagnetic shielding box, a millivoltmeter, a positive electrode test rod, and a negative electrode test rod. The millivoltmeter is placed inside the electromagnetic shielding box. One end of the positive electrode test rod is connected to the millivoltmeter via a wire, and the other end is connected to an anode steel claw. One end of the negative electrode test rod is connected to the millivoltmeter via a wire, and the other end is connected to a reinforcing bar on an anode carbon block. The electromagnetic shielding box includes a box body and an observation window. The box body forms an observation opening, and the observation window is disposed at the observation opening. The observation window includes a first glass layer and a metal mesh. The metal mesh is embedded in the first glass layer. The first glass layer includes glass and a conductive film. The conductive film is formed on the surface of the glass facing the interior of the box body.

[0007] Furthermore, the conductive film is composed of nano-sized indium tin oxide, which is deposited on the surface of the glass to form the conductive film.

[0008] Furthermore, the mesh count of the metal mesh is 100 to 200 mesh.

[0009] Furthermore, the thickness of the first glass layer is 6–8 mm.

[0010] Furthermore, the observation window also includes a second glass layer, which is attached to the first glass layer and is located on the side of the glass facing the outside of the enclosure; the thickness of the first glass layer is 2.5-3mm, and the thickness of the second glass layer is 2.5-4mm.

[0011] Furthermore, the electromagnetic shielding box is made of permalloy.

[0012] Furthermore, the thickness of the box body is 5-10 mm.

[0013] Furthermore, the positive electrode test rod includes a first test copper rod, a base, and a diamond drill bit. The base is disposed at the test end of the first test copper rod, and the diamond drill bit is mounted on the base so that the diamond drill bit passes through the oxide film on the surface of the anode steel claw and abuts against the anode steel claw.

[0014] Furthermore, the diamond drill bit is cone-shaped with a height of 0.4 mm to 0.8 mm.

[0015] Furthermore, the negative electrode test rod includes a second test copper rod and a hexagonal nut. The test end of the second test copper rod is threaded, and the hexagonal nut is screwed to the test end of the second test copper rod and connected to the reinforcing bar on the anode carbon block.

[0016] The aluminum electrolytic cell anode voltage drop testing device provided by this utility model places a millivoltmeter inside an electromagnetic shielding box and sets an observation window at the observation port. The observation window is equipped with a first glass layer and a metal mesh embedded in the first glass layer. A conductive film is set on the surface of the first glass layer facing the outside of the box, so that the electromagnetic shielding box, glass, conductive film and metal mesh form an electromagnetic shielding unit, realizing electromagnetic protection across the entire frequency band and avoiding the problem of inaccurate readings caused by magnetization. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of the aluminum electrolytic cell anode voltage drop testing device in this embodiment of the present invention.

[0019] Figure label:

[0020] 1. Aluminum anode guide rod; 2. Steel claw; 3. Pig iron; 4. Carbon anode block;

[0021] 10. Electromagnetic shielding box; 11. Box body; 12. Observation window; 20. Positive test rod; 30. Negative test rod. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0024] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" or "several" means two or more, unless otherwise explicitly specified.

[0026] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0027] like Figure 1As shown, this application provides an aluminum electrolytic cell anode voltage drop testing device, including an electromagnetic shielding box 10, a millivoltmeter, a positive electrode test rod 20, and a negative electrode test rod 30. The millivoltmeter is placed inside the electromagnetic shielding box 10. One end of the positive electrode test rod 20 is connected to the millivoltmeter via a wire, and the other end is connected to the anode steel claw 2. One end of the negative electrode test rod 30 is connected to the millivoltmeter via a wire, and the other end is connected to the reinforcing bar on the anode carbon block 4. The electromagnetic shielding box 10 includes a box body 11 and an observation window 12. The box body 11 has an observation opening, and the observation window 12 is located at the observation opening. The observation window 12 includes a first glass layer and a metal mesh. The metal mesh is embedded in the first glass layer. The first glass layer includes glass and a conductive film. The conductive film is formed on the surface of the glass facing the interior of the box body 11.

[0028] In this embodiment, the positive electrode test rod 20 and the negative electrode test rod 30 are respectively connected to a millivoltmeter. The test end of the positive electrode test rod 20 is connected to the anode steel claw 2, and the test end of the negative electrode test rod 30 is connected to the anode carbon block 4, forming a test closed loop to detect the anode iron-carbon voltage drop. A small hole can be provided on the electromagnetic shielding box 10 to allow the wires to be led out.

[0029] In this embodiment, the observation window 12 is located at the observation port of the housing 11 of the electromagnetic shielding box 10, and together with the housing 11, it provides electromagnetic shielding protection. A metal mesh is embedded within the first glass layer of the observation window 12 to construct a low-frequency electromagnetic shielding layer, achieving an optimized balance between light transmittance and low-frequency shielding effectiveness. A conductive film is provided on the inner surface of the first glass layer, i.e., the surface of the glass inside the electromagnetic shielding box 10, to shield high-frequency electromagnetic fields. Combined with the basic magnetic shielding function of the electromagnetic shielding box 10, full-band electromagnetic protection is achieved. Placing the millivoltmeter inside the electromagnetic shielding box 10 avoids problems such as wire magnetization and voltmeter pointer magnetization, thus ensuring accurate millivoltmeter readings and enabling accurate measurement of the anode iron-carbon voltage drop.

[0030] In some embodiments, the conductive film is composed of nano-sized indium tin oxide (ITO), which is deposited on the surface of the glass to form the conductive film. In the embodiments of this application, the nano-sized ITO conductive film further maintains the transparency of the first glass layer and constructs a high-frequency electromagnetic shielding layer, ensuring electromagnetic shielding while reading millivoltmeter data.

[0031] In some embodiments, the mesh count of the metal mesh is 100 to 200. In the embodiments of this application, the metal mesh can further maintain the transparency of the first glass layer and construct a low-frequency electromagnetic shielding layer; wherein 150 mesh corresponds to a mesh side length of about 0.1 mm, and the dense mesh enhances the eddy current effect, and the shielding effectiveness against 100Hz low-frequency magnetic fields can reach more than 25dB, which meets the requirements of magnetic circuit shunting and energy dissipation of strong DC magnetic fields (DC~10kHz) in aluminum electrolysis cells.

[0032] The glass layer of the observation window 12 can be a single layer or multiple layers. In some embodiments, the thickness of the first glass layer is 6-8 mm. This application embodiment uses a single glass layer, and the aforementioned thickness range of the first glass layer is set to ensure the mechanical strength of the observation window 12. If the first glass layer is too thick, the light transmittance decreases and raw materials are wasted; if the first glass layer is too thin, the mechanical strength requirement is not met. In the above cases, the glass of the first glass layer can be ordinary tempered glass.

[0033] In some embodiments, the observation window 12 further includes a second glass layer, which is attached to the first glass layer and located on the side of the glass facing the outside of the housing 11. The thickness of the first glass layer is 2.5–3 mm, and the thickness of the second glass layer is 2.5–4 mm. This embodiment uses a double-layered glass system. The first glass layer is made of ordinary glass, and the second glass layer is made of ordinary tempered glass. The second glass layer is located outside the first glass layer, reducing the total thickness by 1–3 mm. This ensures impact resistance and increases light transmittance by 5%–15%, while maintaining equivalent electromagnetic shielding effectiveness and lower thermal stress risk, reducing the risk of cracking by 50%.

[0034] Furthermore, the enclosure 11 of the electromagnetic shielding box 10 is made of permalloy. Specifically, the thickness of the enclosure 11 is 5–10 mm. Understandably, permalloy has high permeability. According to magnetic circuit theory, magnetic fields tend to close through paths with high permeability. The initial permeability of permalloy can reach 20,000–100,000 H / m, far exceeding that of ordinary metals. This allows it to act as a "magnetic short-circuit" path, guiding external magnetic field lines into the shielding body and reducing the magnetic field strength leaking into the enclosure. In the strong DC magnetic field environment of a 400 kA aluminum electrolytic cell, 5 mm thick permalloy can attenuate the magnetic field by 40–60 dB, while industrial pure iron of the same thickness can only achieve 20–30 dB attenuation. In addition, the low saturation magnetic induction intensity of permalloy allows it to maintain linear magnetic permeability within the magnetic field range of the electrolytic cell, avoiding shielding saturation failure due to high magnetic field strength. In contrast, conductive materials such as copper and aluminum rely on eddy current effects for shielding, but these effects weaken significantly with decreasing frequency (becoming completely ineffective under DC magnetic fields), failing to meet the requirements of low-frequency environments. Therefore, the choice of permalloy is essentially based on its high permeability-dominated magnetic shunting mechanism to solve the shielding problem of strong DC and low-frequency magnetic fields, ensuring that the test equipment inside the enclosure is protected from electromagnetic interference.

[0035] In some embodiments, the positive electrode test rod 20 includes a first test copper rod, a base, and a diamond drill bit. The base is disposed at the test end of the first test copper rod, and the diamond drill bit is mounted on the base so that the diamond drill bit passes through the oxide film on the surface of the anode steel claw 2 and abuts against the anode steel claw 2.

[0036] In this embodiment of the positive electrode test rod 20, the first test copper rod serves as the core conductive device. A wire winding and fixing area can be provided at its tail end to achieve circuit connection. A base, made of copper, is provided at the front end of the first test copper rod, and a diamond drill bit is mounted on the base. The diamond drill bit, due to its high hardness, effectively enhances the ability of the positive electrode test rod 20 to pierce the oxide film on the surface of the anode steel claw 2, thereby making the voltage drop measurement more accurate and ensuring that the overall structure balances conductivity and mechanical strength. Specifically, the diamond drill bit is conical in shape, with a height of 0.4mm to 0.8mm. Preferably, the height of the diamond drill bit is 0.5mm. Here, the height of the diamond drill bit refers to the height from the tip of the diamond drill bit to its connection with the base, i.e., the height of the portion exposed above the base.

[0037] In some embodiments, the negative electrode test rod 30 includes a second test copper rod and a hexagonal nut. The test end of the second test copper rod is threaded, and the hexagonal nut is screwed to the test end of the second test copper rod and connected to the reinforcing bar on the anode carbon block 4.

[0038] In this embodiment, the second test copper rod serves as the core conductive device of the negative electrode test rod 30. A wire winding and fixing area is provided at its tail to achieve circuit connection. A thread is provided at the test end of the second test copper rod, and a hexagonal nut is assembled thereon, so that the other end of the hexagonal nut can be connected to the thread of the steel bar on the anode carbon block 4 during testing, thereby realizing the electrical connection between the negative electrode test rod 30 and the anode carbon block 4.

[0039] The aluminum electrolytic cell anode voltage drop testing device of this application embodiment features a diamond drill bit mounted on the positive electrode test rod 20. This drill bit possesses high strength, high wear resistance, and impact resistance, enabling it to penetrate the oxide film. It also has a long service life, is reusable, and saves costs. During use, the diamond drill bit is held perpendicular to the surface of the steel claw 2 and slowly penetrates the oxide film in a rotating manner. Four holes are drilled at equal intervals along the crossbeam of the steel claw 2, and one hole is drilled 3 cm from the bottom of the claw. Measurements are taken to eliminate any additional voltage drop issues associated with the corresponding steel claw 2. The measuring points on the steel claw 2 require polishing. (Refer to...) Figure 1 The anode aluminum guide rod 1 and the steel claw 2 are connected by an explosive weld plate.

[0040] In this embodiment, a threaded steel bar is inserted into the anode carbon block 4. A second test copper rod with a hexagonal nut at the top is fixed to the threaded steel bar using a nut. The second test copper rod is connected to a millivoltmeter to read the iron-carbon voltage drop. Subtracting the additional voltage drop from the excess steel claw 2, the actual anode iron-carbon voltage drop, i.e., the phosphorus pig iron 3 voltage drop, is obtained. The electrolytic aluminum production process is conducted in a high-temperature, strongly magnetized environment. The aforementioned threaded steel bar is selected for its good heat resistance to avoid high-temperature softening. The surface of the conductor can be covered with electromagnetic shielding material.

[0041] The aluminum electrolytic cell anode voltage drop testing device of this application avoids the influence of oxide film on the surface of steel claw 2 and strong magnetic field on millivoltmeter reading. One measuring point is de-oxided with a diamond drill bit, and the other measuring point is clamped with a threaded connection to make the millivoltmeter reading accurate, thereby accurately measuring the anode iron-carbon voltage drop.

[0042] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An aluminium electrolysis cell anode voltage drop testing device characterised in that: The device includes an electromagnetic shielding box, a millivoltmeter, a positive test rod, and a negative test rod. The millivoltmeter is placed inside the electromagnetic shielding box. One end of the positive test rod is connected to the millivoltmeter via a wire, and the other end is connected to the anode steel claw. One end of the negative test rod is connected to the millivoltmeter via a wire, and the other end is connected to the reinforcing bar on the anode carbon block. The electromagnetic shielding box includes a box body and an observation window. The box body has an observation opening, and the observation window is located at the observation opening. The observation window includes a first glass layer and a metal mesh. The metal mesh is embedded in the first glass layer. The first glass layer includes glass and a conductive film. The conductive film is formed on the surface of the glass facing the inside of the box body.

2. The aluminum electrolytic cell anode voltage drop testing device according to claim 1, characterized in that, The conductive film is composed of nano-sized indium tin oxide, which is deposited on the surface of the glass to form the conductive film.

3. The aluminum electrolytic cell anode voltage drop testing device according to claim 1, characterized in that, The mesh size of the metal mesh is 100 to 200 mesh.

4. The aluminum electrolytic cell anode voltage drop testing device according to claim 1, characterized in that, The thickness of the first glass layer is 6-8 mm.

5. The aluminum electrolytic cell anode voltage drop testing device according to claim 1, characterized in that, The observation window also includes a second glass layer, which is attached to the first glass layer and is located on the side of the glass facing the outside of the enclosure; the thickness of the first glass layer is 2.5-3mm, and the thickness of the second glass layer is 2.5-4mm.

6. The aluminum electrolytic cell anode voltage drop testing device according to any one of claims 1 to 5, characterized in that, The electromagnetic shielding box is made of permalloy.

7. The aluminum electrolytic cell anode voltage drop testing device according to claim 6, characterized in that, The thickness of the box is 5-10 mm.

8. The aluminum electrolytic cell anode voltage drop testing device according to any one of claims 1 to 5, characterized in that, The positive electrode test rod includes a first test copper rod, a base, and a diamond drill bit. The base is disposed at the test end of the first test copper rod, and the diamond drill bit is mounted on the base so that the diamond drill bit passes through the oxide film on the surface of the anode steel claw and abuts against the anode steel claw.

9. The aluminum electrolytic cell anode voltage drop testing device according to claim 8, characterized in that, The diamond drill bit is conical in shape, with a height of 0.4 mm to 0.8 mm.

10. The aluminum electrolytic cell anode voltage drop testing device according to any one of claims 1 to 5, characterized in that, The negative electrode test rod includes a second test copper rod and a hexagonal nut. The test end of the second test copper rod is threaded. The hexagonal nut is screwed to the test end of the second test copper rod and connected to the reinforcing bar on the anode carbon block.

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