【Daily Question】Chemical Engineering Principles 313: Preventing Electrolyzer Explosions (February 2)

Keep the groove clean to avoid sparks during power supply； Maintain a tight seal on the electrolyzer to ensure that air from within the shut-down electrolyzer cannot get in ； At the same time, nitrogen purging must be carried out before starting up.

Maintain a tight seal on the electrolyzer to prevent air from entering the shut-down electrolyzer; simultaneously, use nitrogen for purging when starting it up

Keep the groove clean to avoid sparks during power supply； Maintain a tight seal on the electrolyzer to ensure that air from within the shut-down electrolyzer cannot get in ； At the same time, nitrogen purging must be carried out before starting up.

How to prevent explosions in electrolyzers? Answer: Keep the inside of the cell clean to avoid sparks occurring during power application； Maintain a tight seal on the electrolyzer to ensure that air from within the shut-down electrolyzer cannot get in ； At the same time, nitrogen purging must be carried out before starting up.

A lightning arrester is a device in power grids used to protect electrical equipment from lightning impulses. When the lightning impulse wave arriving at the substation along the transmission line exceeds the protection level of the arrester, the arrester discharges first, directing the lightning current safely into the ground through a good conductor. The grounding system is used to keep the amplitude of the lightning voltage below the level that could damage the protected equipment, thereby providing protection for those electrical devices. 　　Based on their sequence of development, lightning arresters can be classified as follows: protective gaps – which represent the simplest form of lightning arresters ； Tubular arrester – it is also a protective gap, but it can extinguish the arc on its own after discharge ； Valve-type arrester – it divides a single discharge gap into many short series gaps, while also adding nonlinear resistance to improve protection performance ； Magnetic blowout arrester – it makes use of a magnetic blowout spark gap, which enhances the arc extinguishing capability; it also has the ability to limit internal overvoltages ； Zinc oxide arresters utilize the ideal volt-ampere characteristics of zinc oxide varistors – which exhibit high non-linearity, meaning they have low resistance at high current levels, thereby limiting the voltage across the arrester; at normal power-frequency voltages, they exhibit high resistance. These arresters have advantages such as no gaps and low residual voltage after current flow stops, and they can also limit internal overvoltages, which is why they are widely used.

Keep the groove clean to avoid sparks during power supply； Maintain a tight seal on the electrolyzer to ensure that air from within the shut-down electrolyzer cannot get in ； At the same time, nitrogen purging must be carried out before starting up.

How to prevent explosions in electrolyzers? Answer: Keep the inside of the cell clean to avoid sparks occurring during power application； Maintain a tight seal on the electrolyzer to ensure that air from within the shut-down electrolyzer cannot get in ； At the same time, nitrogen purging must be carried out before starting up.

How to prevent explosions in electrolyzers? 1. “Prevention is better than disaster relief.” Looking at safety accidents in the aluminum industry, although there are not many different types of such accidents, they occur frequently, have a significant impact, and result in severe losses. As an aluminum electrolysis manufacturer, by identifying the patterns behind accidents and taking preventive measures, some accidents can be completely avoided. In the face of potential major accidents or disasters, in order to ensure rapid, orderly, and effective emergency response actions and to minimize casualties, property losses, and environmental damage caused by such incidents, plans or strategies should be prepared in advance based on an analysis of the consequences of the accidents and the available emergency response capabilities. Aluminum electrolysis companies should purposefully develop emergency measures or plans to address potential hazards that have a significant impact on production and safety, such as furnace leaks, arcing between busbars, sudden power outages, explosions in rectifier cabinets, explosions of molten aluminum during casting, and other related hazards, so as to be prepared for any such situations. 2. Establish an accident early-warning mechanism. Emergency signal systems are installed in the aluminum electrolysis production area and the power supply area, enabling prompt action to cut off power in case of emergencies and ensuring the safety of production processes. Regular accident prevention drills are carried out, such as drills for preventing furnace leaks, joint drills for incidents in the electrolysis area and the power supply area, and drills for sudden power outages. The effectiveness of each drill is evaluated and analyzed to improve the emergency response plans accordingly. Emergency tools, spare parts, and supplies are also prepared and stored. 3. Enhancing the sense of responsibility among operators is also of great significance for preventing accidents. Strengthen the training of operational staff in professional skills to eliminate illegal operations. During the secondary startup of an electrolyzer in a factory, once the baking process of the electrolyzer was complete, too many soft connections were removed before startup due to the poor technical skills and lack of responsibility on the part of the workers. This caused current to flow in an unintended direction, resulting in arcing between the guide rods and the parallel busbars, as well as arcing at the connection points. This led to the damage of the column busbars, almost causing a series of production shutdowns; it is necessary to improve the workers’ ability to assess situations and their keen observational skills. When new aluminum electrolysis plants are built or upgraded, there are usually many new employees and few experienced ones. The technical skills of these new employees are poor, and violations of rules and regulations often occur due to their lack of familiarity with the work or habitual improper working practices. At the same time, delayed or inaccurate detection of abnormal changes in the equipment, along with a lack of keen observation skills, leads to accidents. Therefore, aluminum electrolysis manufacturers must strengthen the training of their workers on operating procedures and safety regulations, in order to improve their ability to analyze, assess, and handle accidents; they should also take prompt action to address any abnormal situations that arise. Under normal circumstances, there are always certain abnormal signs before any accident occurs; it’s just a matter of whether these signs are noticeable or detected in time. On the eve of a leak in an electrolyzer at a certain factory, the levels of iron and silicon impurities in the primary aluminum continued to rise, or there were signs of reddening on the steel plates at the site of the leak. Since this was not given sufficient attention and no preventive measures were taken, a leak occurred. Therefore, managers at all levels should enhance their analysis and judgment of report and chart data, go to the sites in person, be adept at identifying problems or abnormalities, so as to enable timely implementation of countermeasures; they should also strengthen the professional skill training for operators. In recent years, the aluminum industry has seen rapid expansion of production capacity, which has created many job opportunities. Most of the newly hired workers have low educational levels and poor qualifications; some start working on production positions without having received any training, and they are tasked with performing entirely new tasks. Not knowing the standard procedures, they often don’t even know where to begin, making it difficult for them to adapt to their jobs quickly. Therefore, recruitment staff must receive prior training in safety knowledge and professional skills, as well as on-site practice, in order to improve their practical operational abilities. Furthermore, it should also be noted that major production operations should be avoided at night. Aluminum electrolysis is an industry that operates on a continuous basis, with many production processes also being carried out continuously. However, some key operations such as starting up the electrolyzers should be avoided at night whenever possible. According to statistics from recent years, over 80% of accidents occur at night. This is because workers are less energetic and physically stronger at night, and their vision is also inferior to that during the day. Moreover, there are fewer supervisors on the job sites at night, which prevents any violations from being corrected or stopped in a timely manner, thus leading to accidents.

1. Keep the groove clean, 2. Avoid sparks during power supply； 3. Maintain a tight seal on the electrolyzer to ensure that air from within the shut-down electrolyzer cannot enter ； 4. Before starting up simultaneously, it is necessary to purge with nitrogen