Metal smelting, casting, forging, and heat treatment are accompanied by high temperatures, and emit various harmful gases, dust, and smoke, and also generate noise, which seriously deteriorates the working environment and working conditions. There are many working procedures, heavy manual labor, heavy lifting and transportation workload, so it is prone to all kinds of injury accidents, and it is necessary to take targeted safety technical measures. First, metal smelting safety technology (1) High temperature and heat stroke. Metal smelting operations, such as steelmaking and ironmaking, are carried out at high temperatures above a thousand degrees. When working at high temperatures, the human body is affected by the high temperature, and a series of physiological function changes occur, such as a decline in body temperature regulation. When the temperature of the production environment exceeds 34 ° C, heat stroke is likely to occur. If the labor intensity is too large and the labor duration is too long, heat stroke is more likely to occur. In severe cases, it can cause shock. The measures to prevent heat stroke are to rationally design the technological process, improve the production equipment and operation methods, and eliminate or reduce the impact of high temperature and heat radiation on the human body. This is a fundamental measure to improve working conditions in high-temperature operations.
Insulation with water or materials with low thermal conductivity is also an important measure to prevent heatstroke and reduce temperature. The use of mechanical ventilation and natural ventilation is a cost-effective way of heat dissipation. (2) Explosion and burning. In order to improve efficiency and reduce consumption, steel plants often adopt enhanced smelting measures, such as coal injection and oxygen blowing, which makes steel and iron production prone to molten steel, molten iron splashing and explosion accidents. There are many reasons for the splashing and explosion of molten steel and molten iron. The entire production process of producing steel and iron from raw materials hides unsafe factors. The precautions must be strengthened from each process. 1. The personnel in each production position must master the production rules, be familiar with the operating procedures, observe the signs of accidents carefully and understand the handling methods. 2. Strengthen the management and selection of raw materials to prevent explosives and sealed containers from entering the furnace. 3. Regularly check the cooling system to protect the system. Control the cooling water pressure and water volume to prevent the strength of the water cooling system from causing the steel plate to burn through and cause the steel liquid to explode in water. 4. The iron smelting workshop should strictly implement the hot blast stove work system to prevent the hot blast stove from exploding due to furnace replacement accidents; Improper operation causes splashing and explosion accidents in the melting process. 5. When tapping and tapping, heat and dry the iron ditch, molten iron tank, ladle, pit and steel ingot mold in advance. Prevent explosion caused by moisture. (3) Gas poisoning The main harmful component of gas is carbon monoxide. In steelmaking and ironmaking production, especially the waste gas produced in ironmaking production, that is, blast furnace gas, contains high carbon monoxide. Therefore, in steelmaking and ironmaking production, gas poisoning accidents may easily occur if they are not handled well. An effective preventive method is to pay attention to strengthening the ventilation, monitoring, maintenance and personal protection of the production site.
II. Foundry safety technology (1) Features of foundry production. Injecting molten metal into a model or metal model made of molding materials and adhesives to obtain a molded casting is called casting. Casting workers deal with cupolas and electric furnaces. If foreign substances are mixed with molten metal or encounter with water, it may cause explosion and burn injuries. In addition to casting machinery and equipment, casting production also uses a large number of lifting and transportation machinery, which is prone to mechanical injury accidents. Some processes in the casting operation involve a large amount of manual work, and are prone to collision accidents. The process of melting, pouring, sand falling, etc. will emit a lot of heat, affecting workers’ health. To clean the sand, use a vibratory shaker, roller and pneumatic tools, which generate a lot of noise and may cause occupational deafness. Sand-blasting, sand-returning, boxing, and sand-dropping generate a lot of dust. If there is no dust-proof measures, workers are prone to silicosis. During the drying, smelting, pouring, etc. of the core, the oil is decomposed, which will emit acrolein vapor, carbon monoxide, carbon dioxide and other toxic and harmful gases. Without ventilation, it may cause respiratory tract inflammation and acute conjunctivitis. (2) Safety technology for metal melting 1. The main equipment for melting cast iron is a cupola, and its safe operation method is: (1) When repairing the furnace, pay attention to preventing the lining from falling down and hurting the head. The slag ground should prevent the flying pieces from hurting eyes and face. Stand firm during work, taking care not to drop the bottom of the furnace, but also to prevent gas poisoning and other mechanical damage. Before repairing the furnace, the furnace temperature should be below 50 ° C. When working, you must wear bronze cast factory https://www.bronzecast.net/ a safety helmet and have someone under supervision. The feeding port should be equipped with a protective net board and a 12-volt lighting lamp. Blasting is not allowed when repairing the furnace, but the upper eye of the furnace should be fully opened. (2) Be careful to handle the bottom focus before ignition. After adding the bottom coke, open all the tuyere, iron outlet and slag outlet of the cupola, and then ignite to prevent carbon monoxide poisoning. (3) Before feeding, you must wait to check whether the mechanical parts are strong and flexible; fences should be set near the transportation route, and pedestrians are strictly prohibited to pass through or close to the loading machine; when the loading machine is running, it is best to set up a warning sign or a bright red alarm Lamp; the cupola feeding port should be 0.5 meters higher than the feeding table, and the feeding table should be kept neat and clean; when weighing, it should be carefully checked to prevent explosives from mixing into the furnace. (4) During the blast melting operation, the operator should wear protective glasses and stand on the side of the tuyere to monitor. If the furnace shell is burning red, the feeding and air supply should be stopped immediately, and watering is strictly prohibited; when the red area is not more than 75 square centimeters, it can be cooled by blowing. (5) During tapping and slagging, no moisture or moisture is allowed around the cupola, especially the tapping pits and slag tapping tanks should be very dry. If there is water, it must be drained and covered with dry sand of appropriate thickness. All tools used must be painted and dried to prevent burns. (6) When the wind is stopped and the furnace is turned on, the ground must be covered with dry sand to keep it dry; no people can stand around; the operator stands on the upwind side. After the furnace is fired, the red hot iron block and coke are quickly taken out, and the water is not allowed to be blown out, so as to avoid the gas returning to the cupola and causing the furnace explosion. 2. When producing cast steel, the widely used smelting equipment is an electric furnace, and its safe operation methods are: (1) Before the furnace is released, the inclination of the electric melting furnace must not exceed 45, and when slag is stripped, it must not exceed 15-20. To this end, the electric melting furnace should be equipped with a tilt limiter, and the tilting worm drive mechanism should be self-locking. (2) The feed port frame and electrode holder of the electric melting furnace should be equipped with a water cooling circulation device, and the return temperature of the cooling water should not exceed 45. The high-pressure part of the electric melting furnace should be located in a special operating room. For the fumes of the electric melting furnace, measures can be taken for flue gas exhaust and smoke exhaust in the furnace. (3) Safety technology of metal pouring. The main tool for metal pouring is the ladle. The ladle contains high-temperature metal melt, which is dangerous in operation. Pay great attention to safety. The rotating shaft of the ladle shall be provided with a safety device to prevent accidental tilting. When pouring, after the ladle is filled with molten iron, the center of gravity should be more than 100 mm lower than the rotating shaft, and the ladle with a capacity greater than 500 kg must be equipped with a rotating mechanism and be self-locking.
The ladle rotating device shall be provided with a protective shell to prevent the splashed metal from entering and jamming. Pay attention to the quality inspection and test of the ladle. Crane ladle is inspected and tested at least once every six months; hand-lift ladle is inspected and tested once every two months. The crane-type pouring ladle must be subjected to visual inspection and static test.
Insulation with water or materials with low thermal conductivity is also an important measure to prevent heatstroke and reduce temperature. The use of mechanical ventilation and natural ventilation is a cost-effective way of heat dissipation. (2) Explosion and burning. In order to improve efficiency and reduce consumption, steel plants often adopt enhanced smelting measures, such as coal injection and oxygen blowing, which makes steel and iron production prone to molten steel, molten iron splashing and explosion accidents. There are many reasons for the splashing and explosion of molten steel and molten iron. The entire production process of producing steel and iron from raw materials hides unsafe factors. The precautions must be strengthened from each process. 1. The personnel in each production position must master the production rules, be familiar with the operating procedures, observe the signs of accidents carefully and understand the handling methods. 2. Strengthen the management and selection of raw materials to prevent explosives and sealed containers from entering the furnace. 3. Regularly check the cooling system to protect the system. Control the cooling water pressure and water volume to prevent the strength of the water cooling system from causing the steel plate to burn through and cause the steel liquid to explode in water. 4. The iron smelting workshop should strictly implement the hot blast stove work system to prevent the hot blast stove from exploding due to furnace replacement accidents; Improper operation causes splashing and explosion accidents in the melting process. 5. When tapping and tapping, heat and dry the iron ditch, molten iron tank, ladle, pit and steel ingot mold in advance. Prevent explosion caused by moisture. (3) Gas poisoning The main harmful component of gas is carbon monoxide. In steelmaking and ironmaking production, especially the waste gas produced in ironmaking production, that is, blast furnace gas, contains high carbon monoxide. Therefore, in steelmaking and ironmaking production, gas poisoning accidents may easily occur if they are not handled well. An effective preventive method is to pay attention to strengthening the ventilation, monitoring, maintenance and personal protection of the production site.
II. Foundry safety technology (1) Features of foundry production. Injecting molten metal into a model or metal model made of molding materials and adhesives to obtain a molded casting is called casting. Casting workers deal with cupolas and electric furnaces. If foreign substances are mixed with molten metal or encounter with water, it may cause explosion and burn injuries. In addition to casting machinery and equipment, casting production also uses a large number of lifting and transportation machinery, which is prone to mechanical injury accidents. Some processes in the casting operation involve a large amount of manual work, and are prone to collision accidents. The process of melting, pouring, sand falling, etc. will emit a lot of heat, affecting workers’ health. To clean the sand, use a vibratory shaker, roller and pneumatic tools, which generate a lot of noise and may cause occupational deafness. Sand-blasting, sand-returning, boxing, and sand-dropping generate a lot of dust. If there is no dust-proof measures, workers are prone to silicosis. During the drying, smelting, pouring, etc. of the core, the oil is decomposed, which will emit acrolein vapor, carbon monoxide, carbon dioxide and other toxic and harmful gases. Without ventilation, it may cause respiratory tract inflammation and acute conjunctivitis. (2) Safety technology for metal melting 1. The main equipment for melting cast iron is a cupola, and its safe operation method is: (1) When repairing the furnace, pay attention to preventing the lining from falling down and hurting the head. The slag ground should prevent the flying pieces from hurting eyes and face. Stand firm during work, taking care not to drop the bottom of the furnace, but also to prevent gas poisoning and other mechanical damage. Before repairing the furnace, the furnace temperature should be below 50 ° C. When working, you must wear bronze cast factory https://www.bronzecast.net/ a safety helmet and have someone under supervision. The feeding port should be equipped with a protective net board and a 12-volt lighting lamp. Blasting is not allowed when repairing the furnace, but the upper eye of the furnace should be fully opened. (2) Be careful to handle the bottom focus before ignition. After adding the bottom coke, open all the tuyere, iron outlet and slag outlet of the cupola, and then ignite to prevent carbon monoxide poisoning. (3) Before feeding, you must wait to check whether the mechanical parts are strong and flexible; fences should be set near the transportation route, and pedestrians are strictly prohibited to pass through or close to the loading machine; when the loading machine is running, it is best to set up a warning sign or a bright red alarm Lamp; the cupola feeding port should be 0.5 meters higher than the feeding table, and the feeding table should be kept neat and clean; when weighing, it should be carefully checked to prevent explosives from mixing into the furnace. (4) During the blast melting operation, the operator should wear protective glasses and stand on the side of the tuyere to monitor. If the furnace shell is burning red, the feeding and air supply should be stopped immediately, and watering is strictly prohibited; when the red area is not more than 75 square centimeters, it can be cooled by blowing. (5) During tapping and slagging, no moisture or moisture is allowed around the cupola, especially the tapping pits and slag tapping tanks should be very dry. If there is water, it must be drained and covered with dry sand of appropriate thickness. All tools used must be painted and dried to prevent burns. (6) When the wind is stopped and the furnace is turned on, the ground must be covered with dry sand to keep it dry; no people can stand around; the operator stands on the upwind side. After the furnace is fired, the red hot iron block and coke are quickly taken out, and the water is not allowed to be blown out, so as to avoid the gas returning to the cupola and causing the furnace explosion. 2. When producing cast steel, the widely used smelting equipment is an electric furnace, and its safe operation methods are: (1) Before the furnace is released, the inclination of the electric melting furnace must not exceed 45, and when slag is stripped, it must not exceed 15-20. To this end, the electric melting furnace should be equipped with a tilt limiter, and the tilting worm drive mechanism should be self-locking. (2) The feed port frame and electrode holder of the electric melting furnace should be equipped with a water cooling circulation device, and the return temperature of the cooling water should not exceed 45. The high-pressure part of the electric melting furnace should be located in a special operating room. For the fumes of the electric melting furnace, measures can be taken for flue gas exhaust and smoke exhaust in the furnace. (3) Safety technology of metal pouring. The main tool for metal pouring is the ladle. The ladle contains high-temperature metal melt, which is dangerous in operation. Pay great attention to safety. The rotating shaft of the ladle shall be provided with a safety device to prevent accidental tilting. When pouring, after the ladle is filled with molten iron, the center of gravity should be more than 100 mm lower than the rotating shaft, and the ladle with a capacity greater than 500 kg must be equipped with a rotating mechanism and be self-locking.
The ladle rotating device shall be provided with a protective shell to prevent the splashed metal from entering and jamming. Pay attention to the quality inspection and test of the ladle. Crane ladle is inspected and tested at least once every six months; hand-lift ladle is inspected and tested once every two months. The crane-type pouring ladle must be subjected to visual inspection and static test.
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