Electrolytic aluminum anode rod surface oxide layer laser cleaning method

Abstract

The invention provides an electrolytic aluminum anode rod surface oxide layer laser cleaning method which comprises the steps that firstly, an anode rod needing to be cleaned is detached from an electrolytic cell and hoisted to a manual cleaning station, and the position of the anode rod is fixed through a supporting device; then, a handheld laser cleaning head is used for moving in the axial direction of the anode guide rod, and a laser beam irradiates an oxidation area on the surface of the anode guide rod to achieve oxidation layer stripping; in the laser cleaning process, a negative pressure adsorption environment is formed near a cleaning area and used for synchronously removing particles, smoke dust and pyrolysis scraps; after cleaning is finished, the cleaning effect of the conductive contact surface of the anode guide rod is evaluated through visual observation and contact resistance measurement, and whether the anode guide rod can be put into use again is judged according to a detection result. The method has the advantages of being high in cleaning efficiency, free of mechanical damage, reliable in conductivity recovery and the like.

Description

Technical Field

[0001] The present application relates to the technical field of maintenance of electrolytic aluminum production equipment, and in particular to a method for laser cleaning the oxide layer on the surface of an electrolytic aluminum anode guide rod. Background Art

[0002] In the aluminum electrolysis industry, anode guide rods, as core components connecting anode carbon blocks to busbars, perform the crucial functions of high-current conduction and structural support. During long-term operation, a layer of firmly adhered oxidation products often forms on the surface of the anode guide rods due to various factors, including high temperatures, electrochemical corrosion, and the deposition of gaseous impurities. This significantly increases the conductive contact resistance and reduces the contact efficiency between the anode guide rod and the conductive busbar, thereby impacting the stability and energy consumption of the entire electrolytic cell.

[0003] Currently, cleaning the contamination layer on the surface of the anode guide rod still primarily relies on manual mechanical methods, such as wire brushing or polishing with an angle grinder. While these methods are simple to operate and low-cost, they are labor-intensive, inefficient, incomplete descaling, and cause severe dust pollution. Furthermore, due to the numerous uncontrollable factors involved in manual operation, consistent cleaning quality is difficult to maintain. In particular, when the oxide layer on the conductive contact surface is not effectively removed, high contact resistance frequently occurs, significantly impacting the operational safety and energy efficiency of the electrolysis system.

[0004] Existing guide rod cleaning methods are ineffective and prone to fluctuations in conductivity. This is especially true in critical conductive contact areas. Even if the cleaning process appears superficially clean, actual conductivity may still fall short of electrolysis process requirements if residual contamination cannot be completely removed. Therefore, there is an urgent need to develop an anode guide rod cleaning method that can be operated on-site, simultaneously removes contaminants, and provides controllable cleaning results. This method can effectively reduce contact resistance and improve anode guide rod reliability. Summary of the Invention

[0005] The present application provides a laser cleaning method for the oxide layer on the surface of an electrolytic aluminum anode guide rod, which is used to solve the problem that the existing anode guide rod cleaning method using mechanical grinding means has poor cleaning effect and low efficiency.

[0006] The present application provides a laser cleaning method for the oxide layer on the surface of an electrolytic aluminum anode guide rod, comprising the following steps: Step 1: Remove the anode guide rod to be treated in the electrolytic cell and transport it to a location with a manual cleaning station by hoisting. At the cleaning station, fix the anode guide rod on a support device to expose the oxidized area on its surface; Step 2: At the cleaning station, the operator uses a handheld laser cleaning device to move the cleaning head of the device along the surface of the anode guide rod so that the laser beam covers the area where the oxide layer is attached on the surface of the anode guide rod for laser cleaning to remove the oxide layer on the surface of the anode guide rod; the laser emitted by the handheld laser cleaning device is a laser beam output by a fiber laser with a central wavelength of 1080±10nm and an output power of not less than 6kW; Step 3: During the entire laser cleaning process, a negative pressure adsorption environment is created in close proximity to the laser irradiation area, and continuous suction is used to simultaneously remove particles, smoke, and pyrolysis debris generated by laser ablation. Step 4. After cleaning is completed, a cleaning test is carried out. The test content includes: visual observation of the clean area on the surface of the anode guide rod and measurement of the contact resistance of the conductive contact surface of the anode guide rod. After the cleaning test is qualified, the cleaned anode guide rod is reused in the electrolytic cell for continued use; during the cleaning test, it is necessary to observe and confirm that the oxide layer in the cleaned area on the surface of the anode guide rod has been completely removed, and when measuring the contact resistance of the conductive contact surface of the anode guide rod, when the contact resistance measurement value is not greater than the conductive performance reference threshold, the anode guide rod is judged to have passed the cleaning.

[0007] In an optional embodiment, in step 2, when the operator moves the cleaning head of the handheld laser cleaning device, the operator moves the cleaning head back and forth along the axial direction of the anode guide rod in a manner close to the surface of the anode guide rod, so that the laser beam linearly covers the area where the oxide layer adheres to the surface of the anode guide rod; During the movement of the cleaning head, the movement speed of the cleaning head is controlled between 100 and 300 mm per second; the overlap width between adjacent paths is not less than 30% of the laser focal spot diameter; the movement direction is mainly axial to the anode guide rod, supplemented by small radial fine-tuning operations.

[0008] In an optional embodiment, the negative pressure adsorption environment formed in step 3 is achieved by: A suction device is provided at the cleaning station. The suction device includes a suction port arranged above or on one side of the anode guide rod cleaning area. The suction port is connected to an industrial vacuum cleaner with a continuous suction function through a flexible pipe. During the entire laser cleaning process, the suction device is used to synchronously remove particles, smoke, and pyrolysis debris generated during the laser cleaning process. The industrial vacuum equipment operates continuously during the laser cleaning process, and the distance between the suction port and the surface of the anode guide rod cleaning area is controlled between 100 and 300 mm. The opening direction of the suction port points to the laser irradiation area, and the angle between the suction port and the direction of action of the laser beam is controlled between 15 and 45 degrees.

[0009] In an optional embodiment, the industrial vacuum cleaner is an industrial vacuum extractor or exhaust fan with an adjustable air volume function, which can maintain an air suction wind speed of not less than 15 meters per second during the cleaning process. The industrial vacuum cleaner is connected to the suction port through a flexible corrugated connecting pipe, which can form a negative pressure adsorption airflow in the cleaning area.

[0010] In an optional embodiment, before performing step 2, the operator needs to wear protective glasses that meet the laser safety level requirements, and set up a laser protection area at the cleaning station to prevent laser radiation from causing harm to the human body.

[0011] In an optional embodiment, the laser cleaning method is applicable to anode guide rods with a cross-sectional side length of 160 to 200 mm and a length of 1500 to 2600 mm.

[0012] In an optional embodiment, the contact resistance of the conductive contact surface of the anode guide rod is measured in step 4 using a four-terminal method, including the following steps: 1) A pair of current introduction terminals and a pair of voltage detection terminals are respectively provided at both ends of the conductive contact surface, so that the current introduction terminals and the voltage detection terminals are fixedly spaced and in contact with the conductive surface to be measured; 2) A constant current I is applied to the current introduction terminal through a current source, and the voltage drop U across the terminals is measured simultaneously at the voltage detection terminal; 3) Calculate contact resistance according to Ohm's law The contact resistance value is compared with the preset conductivity reference threshold. Make comparisons; 4) When the measured contact resistance ≤ When the conductive contact surface of the anode guide rod is cleaned, it is determined that the cleaning is qualified, wherein the preset conductive performance reference threshold The value is not greater than 1 milliohm.

[0013] In an optional embodiment, in step 2, before performing the laser cleaning operation, the operator presets the laser cleaning parameters according to the thickness and adhesion state of the oxide layer on the surface of the anode guide rod, and the parameters include the laser repetition frequency and the energy density per unit area; the laser repetition frequency is controlled within the range of 10kHz to 200kHz, and the energy density per unit area is controlled within the range of 6 to 12J / cm².

[0014] In an optional embodiment, before executing step 2, the operator identifies the area on the surface of the anode guide rod where the aluminum oxide layer is attached by visual inspection, and marks the identified area with a marking pen or a laser pointer to determine the laser cleaning path.

[0015] In an optional embodiment, during the laser cleaning process, the temperature of the laser irradiation area is monitored by a non-contact infrared thermometer. When the temperature of the surface being cleaned exceeds a safety temperature threshold, the operator adjusts the movement speed of the laser cleaning head or pauses irradiation. The safety temperature threshold is set to 150°C.

[0016] Compared with the prior art, this application has the following beneficial effects: 1. The present application provides a laser cleaning method for the surface oxide layer of an electrolytic aluminum anode guide rod, and proposes to remove the anode guide rod to be cleaned from the electrolytic cell and transfer it to a manual cleaning station by hoisting. At this station, a support device is used to place the anode guide rod so that the oxidized adhesion area is fully exposed. This method of prior transport to a designated location is conducive to avoiding the problems of many blind spots and low efficiency in cleaning caused by direct operation in the confined space of the electrolytic cell, and can reduce potential interference with the cell body and surrounding equipment, thereby creating good environmental conditions for subsequent laser cleaning.

[0017] 2. This application utilizes a handheld laser cleaning device to remove surface oxides from anode guide rods. The laser beam emitted by this handheld laser cleaning device is output by a fiber laser with a central wavelength of 1080±10nm and an output power of no less than 6kW. It possesses a high heat input capability within the irradiated area. Due to its high energy density and thermal shock characteristics, the laser beam can induce rapid thermal cracking or vaporization of the surface oxide layer, thereby achieving the purpose of stripping. This treatment process does not involve mechanical contact, thus avoiding mechanical wear and structural interference while also helping to maintain the surface integrity of the conductive area of ​​the anode guide rod. The operator guides the cleaning head back and forth along the guide rod surface using a handheld device, enabling flexible response to the distribution of contamination in different areas. This is particularly suitable for cleaning irregular or multi-angle areas, thus facilitating precise cleaning. Compared to traditional cleaning methods such as angle grinders, laser treatment can remove a larger area of ​​oxidized residue per unit time while maintaining surface flatness, effectively increasing cleaning speed and reducing manual labor intensity. This significantly improves the problems of existing mechanical methods, such as "incomplete cleaning, inability to brush off, and slow grinding." At the same time, a negative pressure adsorption environment is established in the area near the laser irradiation, and the particles, smoke, and debris generated by laser peeling are discharged in a timely manner by continuous suction. This method can effectively reduce the risk of debris sinking back and avoid repeated contamination in the cleaning area, which is conducive to stabilizing the cleanliness of the cleaning surface.

[0018] 3. This application further sets up a cleaning detection step after the laser cleaning is completed, which mainly includes observing the appearance of the cleaning area and measuring the contact resistance of the conductive contact surface of the anode guide rod. As the first screening link, appearance observation can quickly identify whether the oxidation residue is obvious, which is conducive to timely discovery of cleaning coverage omissions. The measurement of contact resistance is compared and analyzed through the set conductivity threshold, which reflects the actual conductivity after cleaning from a numerical point of view, making the judgment standard clearer and more executable. This application makes the evaluation of cleaning results more reliable through the combination of visual intuitive judgment and quantitative measurement methods. With the help of quantitative detection of cleaning effects, this application helps to reduce potential hidden dangers caused by unmanifested residual contamination and improve the reliability of system operation as a whole. On this basis, only when the visual cleanliness and conductivity of the anode guide rod meet the use requirements, the reassembly stage is entered. Through the closed loop of "laser cleaning-debris removal-conductivity confirmation", continuous control of the entire cleaning process is achieved, which also provides support for ensuring the stability and consistency of the cleaning results. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 This is a flow chart of a method for laser cleaning the oxide layer on the surface of an electrolytic aluminum anode guide rod provided in one embodiment of the present application. DETAILED DESCRIPTION

[0021] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts also fall within the scope of protection of this application.

[0022] like Figure 1 As shown, the embodiment of the present application provides a laser cleaning method for the oxide layer on the surface of an electrolytic aluminum anode guide rod, which specifically includes the following steps: Step S101: dismantle the anode guide rod to be treated in the electrolytic cell and transport it to a location with a manual cleaning station by hoisting. At the cleaning station, fix the anode guide rod on a support device to expose the oxidized area on its surface; Step S102: At the cleaning station, an operator uses a handheld laser cleaning device to move the cleaning head of the device along the surface of the anode guide rod so that the laser beam covers the area where the oxide layer is attached on the surface of the anode guide rod to perform laser cleaning to remove the oxide layer on the surface of the anode guide rod; the laser emitted by the handheld laser cleaning device is a laser beam output by a fiber laser with a central wavelength of 1080±10nm and an output power of not less than 6kW; Step S103: During the entire laser cleaning process, a negative pressure adsorption environment is formed in close proximity to the laser irradiation area, and particles, smoke, and pyrolysis debris generated by laser ablation are removed synchronously using a continuous suction method; Step S104: After the cleaning is completed, a cleaning test is performed, and the test content includes: visual observation of the clean area on the surface of the anode guide rod and measurement of the contact resistance of the conductive contact surface of the anode guide rod. After the cleaning test is qualified, the cleaned anode guide rod is reused in the electrolytic cell for continued use; during the cleaning test, it is necessary to observe and confirm that the oxide layer in the cleaned area on the surface of the anode guide rod has been completely removed, and when measuring the contact resistance of the conductive contact surface of the anode guide rod, when the contact resistance measurement value is not greater than the conductive performance reference threshold, it is determined that the anode guide rod has passed the cleaning.

[0023] In step S101, this embodiment removes the anode guide rod to be cleaned from the electrolytic cell and transports it to a manual cleaning station via a hoisting mechanism. At this station, a support device is used to position the anode guide rod, fully exposing the oxidized areas. This prioritization of the rod to a designated location avoids the numerous blind spots and inefficiencies associated with direct cleaning within the confined space of the electrolytic cell. It also reduces potential interference with the cell and surrounding equipment, creating favorable environmental conditions for subsequent laser cleaning.

[0024] In the operations of step S102 and step S103, a handheld laser cleaning device is used in combination to remove the surface oxides of the anode guide rod. The laser beam emitted by the handheld laser cleaning device is output by a fiber laser, with a central wavelength of 1080±10nm and an output power of not less than 6kW. It has a high heat input capacity in the irradiated area. The laser beam has a high energy density and thermal shock characteristics, which can induce rapid thermal cracking or vaporization of the surface oxide layer, thereby achieving the purpose of stripping. This treatment process does not involve mechanical contact, so while avoiding mechanical wear and structural interference, it is also beneficial to maintain the surface integrity of the conductive area of ​​the anode guide rod. The operator guides the cleaning head to move back and forth along the surface of the guide rod in a handheld manner, which can flexibly respond to the pollution distribution characteristics of different areas. It is especially suitable for cleaning needs of irregular or multi-angle parts, thereby helping to meet the needs of refined cleaning.

[0025] Compared with traditional cleaning methods such as angle grinders, laser processing can remove a larger area of ​​oxidized residue per unit time while maintaining surface flatness, thereby effectively improving the cleaning speed, reducing manual labor intensity, and significantly improving the problems of the original mechanical method of "not being able to clean thoroughly, not being able to brush off, and not being able to grind quickly".

[0026] At the same time, a negative pressure adsorption environment is established in the area near the laser irradiation, and the particles, smoke, and debris generated by laser peeling are discharged in a timely manner by continuous suction. This method can effectively reduce the risk of debris sinking back and avoid repeated contamination in the cleaning area, which is conducive to stabilizing the cleanliness of the cleaning surface.

[0027] This embodiment further provides a cleaning detection step after the laser cleaning is completed, which mainly includes observing the appearance of the cleaned area and measuring the contact resistance of the conductive contact surface of the anode guide rod. As the first screening step, appearance observation can quickly identify whether the oxidation residue is obvious, which is conducive to timely detection of cleaning coverage omissions. The measurement of contact resistance is compared and analyzed through the set conductivity performance threshold, which reflects the actual conductivity after cleaning from a numerical perspective, making the judgment standard clearer and more executable. This embodiment makes the evaluation of cleaning results more reliable by combining visual intuitive judgment with quantitative measurement methods.

[0028] Traditional mechanical polishing methods often cause surface residues due to human factors and operating angle limitations. It is difficult to identify hidden conductive problems based on experience. However, this embodiment effectively avoids this risk through quantitative detection methods, achieving continuous improvement in cleaning quality from the perspective of process closed loop.

[0029] This embodiment utilizes quantitative testing of cleaning effectiveness to help reduce potential hazards caused by undetected residual contamination, thereby improving overall system reliability. Furthermore, reassembly only begins when the anode guide rod's visual cleanliness and conductivity meet operational requirements. This closed-loop process of "laser cleaning - debris removal - conductivity verification" ensures continuous control of the entire cleaning process, ensuring the stability and consistency of cleaning results.

[0030] In some embodiments, in step S102, when the operator moves the cleaning head of the handheld laser cleaning device, the cleaning head is moved back and forth along the axial direction of the anode guide rod so that the laser beam linearly covers the area where the oxide layer adheres to the surface of the anode guide rod; During the movement of the cleaning head, the movement speed of the cleaning head is controlled between 100 and 300 mm per second; the overlap width between adjacent paths is not less than 30% of the laser focal spot diameter; the movement direction is mainly axial to the anode guide rod, supplemented by small radial fine-tuning operations.

[0031] This embodiment specifically describes the movement and path control of the laser cleaning head. During the cleaning process, the operator moves the cleaning head back and forth along the axial direction of the anode guide rod, allowing the laser beam to more evenly cover the oxide adhesion area and achieve an orderly deployment of the linear cleaning trajectory. At the same time, the movement speed is controlled between 100 and 300 mm per second, and an overlap width of no less than 30% of the laser focal spot diameter is preset between adjacent cleaning paths. This path overlap helps reduce blind spots in cleaning and reduces the possibility of localized residue, thereby enhancing the consistency and integrity of the cleaning process.

[0032] This embodiment establishes upper and lower limits on the movement speed, preventing insufficient cleaning intensity due to excessively fast sweeping while also controlling the risk of local overheating caused by excessively slow scanning, thereby maintaining a relatively balanced cleaning efficiency and substrate temperature rise. Furthermore, by incorporating small radial adjustments in addition to axial movement, the laser cleaning head has a certain degree of adaptability to structural features such as uneven surfaces and bent corners on the anode guide rod, thus avoiding uneven cleaning due to localized surface fluctuations.

[0033] In other optional embodiments, the cleaning head's movement strategy can be adjusted appropriately based on the thickness distribution of the oxide layer, the surface topography of the guide rod, or the difference in contaminant adhesion patterns. For example, a circular, spiral, or zigzag path can be used to perform localized reinforcement cleaning on thick or irregularly adhered areas to improve the stripping effect.

[0034] The above-mentioned operation strategies comprehensively improve the process stability of laser cleaning and help achieve more sufficient oxide layer removal effect under complex configurations.

[0035] In some optional situations, to further improve cleaning uniformity or accommodate cleaning requirements for highly adherent oxide layers, the overlap width between adjacent paths can be set to 40% to 60% of the laser focal spot diameter. This greater path overlap helps increase the composite coverage of laser energy in the boundary area, thereby enhancing the oxide layer stripping effect at the edge. This is particularly suitable for applications with uneven contamination layer thickness or high cleaning precision requirements. This adjustable range provides flexible process options, allowing operators to make targeted adjustments based on on-site conditions.

[0036] In some embodiments, the negative pressure adsorption environment formed in step S103 is achieved by: A suction device is provided at the cleaning station. The suction device includes a suction port arranged above or on one side of the anode guide rod cleaning area. The suction port is connected to an industrial vacuum cleaner with a continuous suction function through a flexible pipe. During the entire laser cleaning process, the suction device is used to synchronously remove particles, smoke, and pyrolysis debris generated during the laser cleaning process. The industrial vacuum equipment operates continuously during the laser cleaning process. The distance between the suction port and the surface of the anode guide rod cleaning area is controlled between 100 and 300 mm. The opening direction of the suction port points to the laser irradiation area, and the angle between the suction port and the direction of the laser beam is controlled between 15 and 45 degrees.

[0037] In the above embodiment, the implementation method of the negative pressure adsorption environment is clearly described. In this embodiment, a suction device is provided at the cleaning station, and a suction port is reasonably arranged above or on the side of the area to be cleaned of the anode guide rod. The suction port is connected to an industrial vacuum cleaner with a continuous suction function through a flexible pipe. In the specific arrangement, the distance between the suction port and the surface to be cleaned is controlled within an appropriate range of 100 to 300 mm, and the direction of its opening is directed to the laser irradiation position, while forming an angle of about 15 to 45 degrees with the direction of action of the laser beam. This structural layout enables the suction device to be better close to the laser action area, and to promptly adsorb and discharge the smoke, particles and pyrolysis debris generated during the cleaning process, effectively reducing the secondary sedimentation of these debris on the surface of the guide rod. This timely debris removal measure helps to improve the cleanliness of the surface after cleaning, reduce the possibility of subsequent contamination of the conductive contact area, and has a positive effect on maintaining the stability and consistency of the conductive performance of the anode guide rod when it is used again.

[0038] In some embodiments, the industrial vacuum cleaner is an industrial vacuum extractor or exhaust fan with adjustable air volume function, which can maintain an air suction wind speed of not less than 15 meters per second during the cleaning process. The industrial vacuum cleaner is connected to the suction port through a flexible corrugated connecting pipe, which can form a negative pressure adsorption airflow in the cleaning area.

[0039] This embodiment further optimizes the performance of the industrial dust collection equipment, selects an industrial vacuum extractor or industrial exhaust fan with an air volume adjustment function, and connects it to the suction port through a flexible corrugated connecting pipe. This design method can more flexibly regulate the flow rate of the suction airflow, and maintain the wind speed in the area near the suction port at a level of not less than 15 meters per second during the laser cleaning process, thereby facilitating the timely and effective removal of particles and pyrolysis gases released from the laser irradiation area. At the same time, the provision of the flexible connecting pipe makes it more convenient to adjust the position of the suction port. When faced with different cleaning conditions or shapes of the anode guide rod, the operator can quickly and easily adjust the direction and distance of the suction port, thereby better avoiding interference with the laser beam path. This flexible structural layout can form a relatively stable negative pressure airflow environment in the cleaning operation area, thereby effectively reducing the possibility of particle accumulation, dust suspension or backflow into the working environment, and is also conducive to maintaining the clean state of the surface of the guide rod to be cleaned.

[0040] In some embodiments, before executing step S102, the operator needs to wear protective glasses that meet the laser safety level requirements, and set up a laser protection area at the cleaning station to prevent laser radiation from causing harm to the human body.

[0041] This embodiment incorporates laser safety protection measures into the process flow. A dedicated laser protection area is arranged within the cleaning station, and before laser cleaning is carried out, the operator is required to wear protective glasses that meet the corresponding laser safety level requirements to reduce the risk of injury to the operator from laser radiation. Considering that the output power of the selected fiber laser is relatively high, reaching 6kW or above, the energy density of the laser beam in the active area is relatively high. If effective protective measures are not taken, laser radiation can easily cause damage to the eyes of the operator, and there may even be potential hidden dangers in the non-direct irradiation area due to laser scattering. Therefore, setting up a closed or semi-closed laser protection area can effectively limit the spatial range of laser beam propagation; and wearing protective glasses as an individual protection measure can further reduce the possibility of direct or reflected laser damage to the operator's eyes. This dual protection method combining station and individual protection reduces the safety risks in handheld laser cleaning operations to a certain extent, is conducive to protecting the health and safety of operators, and at the same time takes into account the balance between the efficiency and safety of the operation process.

[0042] In some embodiments, the laser cleaning method is applicable to anode guide rods having a cross-sectional side length of 160 to 200 mm and a length of 1500 to 2600 mm.

[0043] This embodiment clearly defines the applicable size range for anode guide rods: the cross-sectional side length is set to 160 to 200 mm, and the length is controlled within the range of 1500 to 2600 mm. This size range ensures that the laser cleaning method is well matched to the dimensions of standard anode guide rods commonly used in the electrolytic aluminum industry, which helps improve the process adaptability in practical applications.

[0044] Since the anode guide rod is usually a rod-shaped structure with a large cross-section and a long length, and the surface oxide layer is irregularly distributed and has various shapes, this application puts forward certain conditions and requirements for the output power of the laser equipment, the irradiation range of the laser beam, the operator's operating space, and the specific layout of the suction device.

[0045] In some embodiments, the contact resistance of the conductive contact surface of the anode guide rod is measured in step S104 using a four-terminal method, including the following steps: 1) A pair of current introduction terminals and a pair of voltage detection terminals are respectively provided at both ends of the conductive contact surface, so that the current introduction terminals and the voltage detection terminals are fixedly spaced and in contact with the conductive surface to be measured; 2) A constant current I is applied to the current introduction terminal through a current source, and the voltage drop U across the terminals is measured simultaneously at the voltage detection terminal; 3) Calculate contact resistance according to Ohm's law The contact resistance value is compared with the preset conductivity reference threshold. Make comparisons; 4) When the measured contact resistance ≤ When the conductive contact surface of the anode guide rod is cleaned, the conductive performance reference threshold is preset. The value is not greater than 1 milliohm.

[0046] In the cleaning effect detection link of step S104, this embodiment uses a four-terminal method to measure the contact resistance of the conductive contact surface, thereby improving the accuracy of the cleaning effect evaluation. In the specific implementation process, the current introduction terminal and the voltage detection terminal are independently attached to different positions of the conductive contact surface to form a current path and a voltage measurement path that do not interfere with each other. By applying a constant current to the current introduction terminal and measuring the voltage drop on the voltage detection terminal at the same time, the formula The actual contact resistance value can be obtained. Then the measured value is compared with the pre-set conductivity reference threshold. Comparison facilitates intuitive judgment of whether the conductivity of the anode guide rods after cleaning meets actual process requirements. This quantitative testing method, based on electrical performance indicators, effectively reduces the influence of subjective judgment on the results and can more objectively reflect the cleaning quality of the guide rods. This method also facilitates rapid on-site inspection and subsequent quality traceability of cleaning operations, helping to improve the stability of current transmission and the effectiveness of energy consumption management during the long-term operation of the electrolyzer.

[0047] In specific applications, in order to further enhance the pertinence and flexibility of the assessment, the set conductivity reference threshold can be adjusted according to the electrolytic cell operating parameters, current density requirements and the actual structural dimensions of the anode guide rod. In some high-demand application scenarios, the reference threshold of contact resistance is preferred, that is, the preset conductivity reference threshold The range can be limited to 0.2 to 0.8 milliohms to better reflect the need for refined control of conductive stability and low-energy operation.

[0048] In some embodiments, in step S102, before performing the laser cleaning operation, the operator presets the laser cleaning parameters according to the thickness and adhesion state of the oxide layer on the surface of the anode guide rod, and the parameters include the laser repetition frequency and the energy density per unit area; wherein the laser repetition frequency is controlled within the range of 10kHz to 200kHz, and the energy density per unit area is controlled within the range of 6 to 12J / cm².

[0049] Before performing the laser cleaning operation, this embodiment clearly pre-sets the parameters for laser cleaning, including the laser repetition frequency and the energy density per unit area, making the laser processing process more targeted. This approach helps to improve the stability and controllability of the cleaning operation and enhance the predictability of the surface cleaning effect. Specifically, by controlling the laser repetition frequency between 10kHz and 200kHz, it is possible to reasonably select a suitable pulse output frequency based on the actual thickness of the oxide layer on the surface of the anode guide rod and its adhesion strength to the substrate. This selection method is conducive to avoiding potential damage to the guide rod substrate when the laser energy is too concentrated, and can also prevent the problem of poor oxide layer removal effect due to insufficient energy.

[0050] Furthermore, the energy density per unit area is preset within a range of 6 to 12 J / cm². This setting provides the laser beam with optimal energy levels, promoting sufficient thermal decomposition and stripping of the oxide layer. Furthermore, by properly controlling the energy density distribution, the risk of overheating or damage to localized areas of the guide rod due to excessive heat is reduced.

[0051] In this embodiment, through the appropriate setting of the above parameters, the laser cleaning process can better match the degree of contamination on the surface of the anode guide rod, so that the cleaning effect shows good consistency on the anode guide rods with different degrees of contamination, which helps to reduce the problems of repeated cleaning and fluctuations in local cleaning effects, and plays a positive role in improving the overall operating efficiency of the equipment and the subsequent reuse performance of the anode guide rod.

[0052] Energy density ε is the laser energy received per unit area (joules / square centimeter), which determines whether the aluminum oxide layer on the surface of the anode guide rod can be effectively removed.

[0053] The definition formula is: in: : average laser output power (watt, W), : Focus spot area (square centimeters), : pulse repetition frequency (Hz); Before cleaning, the operator can set the average power ≥ 6kW and repetition frequency through the laser panel; use the laser beam profiler to measure the focal spot diameter, and use the formula Calculate the energy density. If it is not within the target range, adjust the focal length or output power.

[0054] In some embodiments, before executing step S102 , the operator identifies the aluminum oxide layer adhesion area on the surface of the anode guide rod through visual inspection, and marks the identified area with a marker pen or a laser pointer to determine the laser cleaning path.

[0055] This embodiment predefines the cleaning path by visually inspecting the distribution of the aluminum oxide layer on the anode guide rod surface before the laser cleaning operation begins. The operator then uses a marker pen or laser pointer to mark the area to be treated. This pre-processing step helps to clearly define the laser's active area, reducing the possibility of missing or incorrectly cleaning areas. The markings, applied directly to the guide rod's outer surface, provide a clear reference for the operator during subsequent cleaning, allowing the laser beam to be more closely focused on the target area and achieving more uniform trajectory coverage. This can also be used to adjust the movement direction during the cleaning process, reducing repeated scanning.

[0056] In some embodiments, during the laser cleaning process, the temperature of the laser irradiation area is monitored by a non-contact infrared thermometer. When the temperature of the surface being cleaned exceeds a safety temperature threshold, the operator adjusts the movement speed of the laser cleaning head or pauses irradiation. The safety temperature threshold is set to 150°C.

[0057] This embodiment incorporates a non-contact infrared thermometer during the laser cleaning process to dynamically monitor the temperature of the laser-irradiated area on the anode guide rod surface. If the monitoring results indicate that the surface temperature exceeds a safe temperature threshold (150°C), the operator can adjust the laser cleaning head's movement speed or terminate laser irradiation to mitigate heat accumulation. Using a non-contact infrared thermometer for temperature monitoring eliminates the need for direct contact with the anode guide rod and offers excellent resistance to radiation interference and a fast response, making it suitable for continuous operation in high-temperature, high-energy environments. During laser cleaning, the concentrated energy density of the beam spot can easily cause localized rapid temperature rise within a short period of time. If uncontrolled, this can lead to corrosion, minor deformation, or residual stress on the guide rod surface, adversely affecting its subsequent conductive properties. By setting a safe temperature threshold and combining it with manual intervention for simple and efficient temperature control, the thermal stability of the process is improved while also enhancing the operational flexibility and safety of the entire cleaning process without the need for a complex closed-loop control system.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A laser cleaning method for the surface oxide layer of an electrolytic aluminum anode guide rod, characterized in that: The following steps are involved: Step 1: Remove the anode guide rod to be treated in the electrolytic cell and transport it to a location with a manual cleaning station by hoisting. At the cleaning station, fix the anode guide rod on a support device to expose the oxidized area on its surface; Step 2: At the cleaning station, the operator uses a handheld laser cleaning device to move the cleaning head of the device along the surface of the anode guide rod so that the laser beam covers the area where the oxide layer is attached on the surface of the anode guide rod for laser cleaning to remove the oxide layer on the surface of the anode guide rod; the laser emitted by the handheld laser cleaning device is a laser beam output by a fiber laser with a central wavelength of 1080±10nm and an output power of not less than 6kW; Step 3: During the entire laser cleaning process, a negative pressure adsorption environment is created in close proximity to the laser irradiation area, and continuous suction is used to simultaneously remove particles, smoke, and pyrolysis debris generated by laser ablation. Step 4. After cleaning is completed, a cleaning test is carried out. The test content includes: visual observation of the clean area on the surface of the anode guide rod and measurement of the contact resistance of the conductive contact surface of the anode guide rod. After the cleaning test is qualified, the cleaned anode guide rod is reused in the electrolytic cell for continued use; during the cleaning test, it is necessary to observe and confirm that the oxide layer in the cleaned area on the surface of the anode guide rod has been completely removed, and when measuring the contact resistance of the conductive contact surface of the anode guide rod, when the contact resistance measurement value is not greater than the conductive performance reference threshold, the anode guide rod is judged to have passed the cleaning.

2. The laser cleaning method for the surface oxide layer of the electrolytic aluminum anode guide rod according to claim 1, characterized in that: In step 2, when the operator moves the cleaning head of the handheld laser cleaning device, the operator moves the cleaning head back and forth along the axial direction of the anode guide rod in a manner close to the surface of the anode guide rod, so that the laser beam achieves linear coverage of the area where the oxide layer adheres to the surface of the anode guide rod; During the movement of the cleaning head, the movement speed of the cleaning head is controlled between 100 and 300 mm per second; the overlap width between adjacent paths is not less than 30% of the laser focal spot diameter; the movement direction is mainly axial to the anode guide rod, supplemented by small radial fine-tuning operations.

3. The laser cleaning method for the surface oxide layer of the electrolytic aluminum anode guide rod according to claim 1 or 2, characterized in that: The negative pressure adsorption environment formed in step 3 is achieved by the following methods: A suction device is provided at the cleaning station. The suction device includes a suction port arranged above or on one side of the anode guide rod cleaning area. The suction port is connected to an industrial vacuum cleaner with a continuous suction function through a flexible pipe. During the entire laser cleaning process, the suction device is used to synchronously remove particles, smoke, and pyrolysis debris generated during the laser cleaning process. The industrial vacuum equipment operates continuously during the laser cleaning process, and the distance between the suction port and the surface of the anode guide rod cleaning area is controlled between 100 and 300 mm. The opening direction of the suction port points to the laser irradiation area, and the angle between the suction port and the direction of action of the laser beam is controlled between 15 and 45 degrees.

4. The laser cleaning method for the surface oxide layer of the electrolytic aluminum anode guide rod according to claim 3, characterized in that: The industrial vacuum cleaner is an industrial vacuum extractor or exhaust fan with an adjustable air volume function, which can maintain an air suction speed of not less than 15 meters per second during the cleaning process. The industrial vacuum cleaner is connected to the suction port through a flexible corrugated connecting pipe, which can form a negative pressure adsorption airflow in the cleaning area.

5. The laser cleaning method for the surface oxide layer of the electrolytic aluminum anode guide rod according to claim 1, characterized in that: Before performing step 2, the operator must wear protective glasses that meet the laser safety level requirements and set up a laser protection area at the cleaning station to prevent laser radiation from causing harm to the human body.

6. The laser cleaning method for the surface oxide layer of the electrolytic aluminum anode guide rod according to claim 1, characterized in that: The laser cleaning method is suitable for anode guide rods with a cross-sectional side length of 160 to 200 mm and a length of 1500 to 2600 mm.

7. The laser cleaning method for the surface oxide layer of the electrolytic aluminum anode guide rod according to claim 1, characterized in that: In step 4, the contact resistance of the conductive contact surface of the anode guide rod is measured using a four-terminal method, which includes the following steps: 1) A pair of current introduction terminals and a pair of voltage detection terminals are respectively provided at both ends of the conductive contact surface, so that the current introduction terminals and the voltage detection terminals are fixedly spaced and in contact with the conductive surface to be measured; 2) A constant current I is applied to the current introduction terminal through a current source, and the voltage drop U across the terminals is measured simultaneously at the voltage detection terminal; 3) Calculate contact resistance according to Ohm's law The contact resistance value is compared with the preset conductivity reference threshold. Make comparisons; 4) When the measured contact resistance ≤ When the conductive contact surface of the anode guide rod is cleaned, it is determined that the cleaning is qualified, wherein the preset conductive performance reference threshold The value is not greater than 1 milliohm.

8. The laser cleaning method for the surface oxide layer of the electrolytic aluminum anode guide rod according to claim 1, characterized in that: In step 2, before performing the laser cleaning operation, the operator presets the laser cleaning parameters based on the thickness and adhesion state of the oxide layer on the surface of the anode guide rod. The parameters include the laser repetition frequency and the energy density per unit area. The laser repetition frequency is controlled within the range of 10 kHz to 200 kHz, and the energy density per unit area is controlled within the range of 6 to 12 J / cm².

9. The laser cleaning method for the surface oxide layer of the electrolytic aluminum anode guide rod according to claim 1, characterized in that: Before executing step 2, the operator identifies the aluminum oxide layer adhesion area on the surface of the anode guide rod through visual inspection and marks the identified area with a marking pen or a laser pointer to determine the laser cleaning path.

10. The laser cleaning method for the surface oxide layer of the electrolytic aluminum anode guide rod according to claim 1, characterized in that: During the laser cleaning process, the temperature of the laser irradiation area is monitored by a non-contact infrared thermometer. When the temperature of the surface being cleaned exceeds the safety temperature threshold, the operator adjusts the movement speed of the laser cleaning head or suspends irradiation. The safety temperature threshold is set at 150°C.

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