The hazards and prevention of batteries
发布时间：2024-11-28 22:44:39 点击： 次
Batteries, as a convenient and applicable DC power source, are widely used in power plants, industrial and mining enterprise substations, and various types of motor vehicles. Due to the hazardous characteristics of lead poisoning, flammability, and explosiveness involved in the assembly process of lead-acid batteries, ensuring the safe production of lead-acid batteries is crucial. Below, the editor will introduce the hazards of batteries and their prevention measures.
The hazards of batteries
The main dangers and hazards that may arise during the assembly process of lead-acid batteries are poisoning, fire, explosion, as well as high temperature burns, mechanical injuries, corrosion injuries, etc. Due to space limitations, only three factors of poisoning, fire, and explosion will be analyzed.
There is a large amount of lead dust in the weighing and packaging areas, which belong to the heavily polluted areas of lead and are prone to chronic lead poisoning. The harm of lead poisoning to the human body is mainly concentrated in the digestive system and nervous system. The proportion of occupational chronic lead poisoning among operators working in battery factories is as high as 25% to 30%. More seriously, lead poisoning is not limited to adult operators in battery factories, and even many children in the surrounding area have experienced lead poisoning reactions. In June 2004, hundreds of lead poisoning incidents occurred in a certain county.
The main reasons for these poisoning accidents are the lack of necessary ventilation and environmental protection equipment in the factory area. Although some manufacturers have it, they do not turn it on during work, which is virtually non-existent. Workers lack necessary labor protection equipment and their self-protection awareness is weak. Weighing and packaging are key areas that can cause lead poisoning, and there must be comprehensive protective measures and exhaust systems in place.
According to the process requirements, the fire hazard of acetylene and liquefied petroleum gas used in the welding area is Class A, and the fire hazard of oxygen is Class B. The explosive limit of acetylene in air is 2.1% to 80.0% (υ/υ), and the ignition temperature is around 305 ℃; The explosion limit of liquefied petroleum gas in air is 2.25% to 9.65% (υ/υ), and the ignition temperature is around 426-537 ℃. Therefore, the biggest risk factors in the production process are fire and explosion. Improper operation, severe collision or being too close to open flames, and high temperatures during the welding of pole groups and poles can all cause fire and explosion.
According to the working principle of lead-acid batteries, the positive electrode active material is lead dioxide, the negative electrode active material is sponge lead, and the electrolyte is dilute sulfuric acid solution. When the battery is charged to 70% to 80% capacity, the positive electrode begins to produce oxygen, and when the charging is basically completed by about 90%, the negative electrode begins to produce hydrogen. Hydrogen is a flammable and explosive Class A substance, with an explosive limit of 4.1% to 74.1% in air and an ignition temperature of around 450 ℃. Therefore, the concentration of hydrogen in the charging room is highly likely to reach the explosive limit, and it will ignite once a source of fire occurs. For example, on July 3, 1991, a lead-acid battery room at a power station experienced a fire and explosion accident, resulting in the death of one inspector and serious damage to charging equipment and batteries. The main cause of the accident was the failure of the ventilation equipment for the battery, resulting in the accumulation of indoor hydrogen gas. The inspection worker seriously violated regulations by smoking and causing an explosion with an open flame during the inspection.
Battery safety precautions
As mentioned above, the main hazards during battery assembly are poisoning, fire, explosion, etc. To ensure safe production, the following safety measures are recommended:
1. The site selection must maintain a necessary safety protection distance from surrounding residents and public facilities, and must meet the requirements of the "Code for Fire Protection Design of Buildings", "Safety and Health Regulations for Lead Operations", "Hygiene Standards for Industrial Enterprise Design", and "Labor Protection Regulations for Workplaces Using Toxic Substances".
2. Try to keep the operating environment moist as much as possible before starting work to prevent lead dust from flying; During work, workers must not only wear appropriate work clothes and dust masks, but also use ventilation facilities that can ensure fresh air supply; The lead dust emitted from the operation platform must be placed in a dedicated container and must not be piled up with other garbage or other materials; After homework, workers must take a shower and wash their work clothes and dust masks in the factory; Smoking, eating, etc. should be prohibited in the workplace at the same time; Before drinking water in class, it is necessary to wash hands, face, and rinse mouth. It is strictly prohibited to wear work clothes into the cafeteria or leave the factory.
Gas cylinders in the workshop shall not be stacked randomly or mixed with different gas cylinders. Although acetylene, liquefied petroleum gas, and oxygen are used the least, gas cylinders still need to be stored separately. The storage area should be built with brick walls and prefabricated panels on the exterior walls of the production workshop as an intermediate warehouse for liquefied petroleum gas and oxygen. Doors with louvers at the bottom should be selected, ventilation openings should be left on both sides of the walls, and steel wire mesh should be installed to maintain good ventilation. The door is open outside the workshop and a sign prohibiting open flames and smoking is prominently posted. According to the "Code for Fire Protection Design of Buildings", this storage area can only be used as an intermediate warehouse in the workshop, and the storage quantity of acetylene should not exceed 25m3 (under standard conditions). The storage quantity of liquefied petroleum gas should not exceed 50m3 (under standard conditions). Special personnel shall be responsible for the storage and use of oxygen and acetylene. Overpressure use and artificial heating of gas cylinders are strictly prohibited. It is strictly forbidden to open the valve of oxygen cylinders with gloves contaminated with oil; Before starting the operation, the operator must first check whether the connection between the hose and the welding is secure, and whether the hose has any knots.
4. The charging area should maintain good ventilation, and if necessary, explosion-proof ventilation equipment should be added. At the same time, combustible gas concentration leak detection and alarm devices should be installed, and meet the relevant requirements of the "Design Specification for Fire Automatic Alarm System". Non explosion proof electrical equipment (such as switches, sockets, fuses, and lamps) are not allowed to be used in the charging area. Smoking, using open flames for lighting or heating is strictly prohibited in the charging area; No hot work is allowed indoors. Indoor electrical circuits should be laid in conduits, and electrical connections should have good and secure contact, without looseness, to avoid spark discharge. Do not wear synthetic clothing when entering the charging area to avoid friction and discharge.
The hazards of batteries
The main dangers and hazards that may arise during the assembly process of lead-acid batteries are poisoning, fire, explosion, as well as high temperature burns, mechanical injuries, corrosion injuries, etc. Due to space limitations, only three factors of poisoning, fire, and explosion will be analyzed.
There is a large amount of lead dust in the weighing and packaging areas, which belong to the heavily polluted areas of lead and are prone to chronic lead poisoning. The harm of lead poisoning to the human body is mainly concentrated in the digestive system and nervous system. The proportion of occupational chronic lead poisoning among operators working in battery factories is as high as 25% to 30%. More seriously, lead poisoning is not limited to adult operators in battery factories, and even many children in the surrounding area have experienced lead poisoning reactions. In June 2004, hundreds of lead poisoning incidents occurred in a certain county.
The main reasons for these poisoning accidents are the lack of necessary ventilation and environmental protection equipment in the factory area. Although some manufacturers have it, they do not turn it on during work, which is virtually non-existent. Workers lack necessary labor protection equipment and their self-protection awareness is weak. Weighing and packaging are key areas that can cause lead poisoning, and there must be comprehensive protective measures and exhaust systems in place.
According to the process requirements, the fire hazard of acetylene and liquefied petroleum gas used in the welding area is Class A, and the fire hazard of oxygen is Class B. The explosive limit of acetylene in air is 2.1% to 80.0% (υ/υ), and the ignition temperature is around 305 ℃; The explosion limit of liquefied petroleum gas in air is 2.25% to 9.65% (υ/υ), and the ignition temperature is around 426-537 ℃. Therefore, the biggest risk factors in the production process are fire and explosion. Improper operation, severe collision or being too close to open flames, and high temperatures during the welding of pole groups and poles can all cause fire and explosion.
According to the working principle of lead-acid batteries, the positive electrode active material is lead dioxide, the negative electrode active material is sponge lead, and the electrolyte is dilute sulfuric acid solution. When the battery is charged to 70% to 80% capacity, the positive electrode begins to produce oxygen, and when the charging is basically completed by about 90%, the negative electrode begins to produce hydrogen. Hydrogen is a flammable and explosive Class A substance, with an explosive limit of 4.1% to 74.1% in air and an ignition temperature of around 450 ℃. Therefore, the concentration of hydrogen in the charging room is highly likely to reach the explosive limit, and it will ignite once a source of fire occurs. For example, on July 3, 1991, a lead-acid battery room at a power station experienced a fire and explosion accident, resulting in the death of one inspector and serious damage to charging equipment and batteries. The main cause of the accident was the failure of the ventilation equipment for the battery, resulting in the accumulation of indoor hydrogen gas. The inspection worker seriously violated regulations by smoking and causing an explosion with an open flame during the inspection.
Battery safety precautions
As mentioned above, the main hazards during battery assembly are poisoning, fire, explosion, etc. To ensure safe production, the following safety measures are recommended:
1. The site selection must maintain a necessary safety protection distance from surrounding residents and public facilities, and must meet the requirements of the "Code for Fire Protection Design of Buildings", "Safety and Health Regulations for Lead Operations", "Hygiene Standards for Industrial Enterprise Design", and "Labor Protection Regulations for Workplaces Using Toxic Substances".
2. Try to keep the operating environment moist as much as possible before starting work to prevent lead dust from flying; During work, workers must not only wear appropriate work clothes and dust masks, but also use ventilation facilities that can ensure fresh air supply; The lead dust emitted from the operation platform must be placed in a dedicated container and must not be piled up with other garbage or other materials; After homework, workers must take a shower and wash their work clothes and dust masks in the factory; Smoking, eating, etc. should be prohibited in the workplace at the same time; Before drinking water in class, it is necessary to wash hands, face, and rinse mouth. It is strictly prohibited to wear work clothes into the cafeteria or leave the factory.
Gas cylinders in the workshop shall not be stacked randomly or mixed with different gas cylinders. Although acetylene, liquefied petroleum gas, and oxygen are used the least, gas cylinders still need to be stored separately. The storage area should be built with brick walls and prefabricated panels on the exterior walls of the production workshop as an intermediate warehouse for liquefied petroleum gas and oxygen. Doors with louvers at the bottom should be selected, ventilation openings should be left on both sides of the walls, and steel wire mesh should be installed to maintain good ventilation. The door is open outside the workshop and a sign prohibiting open flames and smoking is prominently posted. According to the "Code for Fire Protection Design of Buildings", this storage area can only be used as an intermediate warehouse in the workshop, and the storage quantity of acetylene should not exceed 25m3 (under standard conditions). The storage quantity of liquefied petroleum gas should not exceed 50m3 (under standard conditions). Special personnel shall be responsible for the storage and use of oxygen and acetylene. Overpressure use and artificial heating of gas cylinders are strictly prohibited. It is strictly forbidden to open the valve of oxygen cylinders with gloves contaminated with oil; Before starting the operation, the operator must first check whether the connection between the hose and the welding is secure, and whether the hose has any knots.
4. The charging area should maintain good ventilation, and if necessary, explosion-proof ventilation equipment should be added. At the same time, combustible gas concentration leak detection and alarm devices should be installed, and meet the relevant requirements of the "Design Specification for Fire Automatic Alarm System". Non explosion proof electrical equipment (such as switches, sockets, fuses, and lamps) are not allowed to be used in the charging area. Smoking, using open flames for lighting or heating is strictly prohibited in the charging area; No hot work is allowed indoors. Indoor electrical circuits should be laid in conduits, and electrical connections should have good and secure contact, without looseness, to avoid spark discharge. Do not wear synthetic clothing when entering the charging area to avoid friction and discharge.