Four key safety prevention and control measures for chemical enterprises in winter

Thread Content

This post was last edited by yinkuilin6868 on 2015-12-14 at 10:04. With the arrival of winter, the weather in the north becomes cold and dry, increasing the risk of injuries such as frostbite, poisoning, and slips. There is also a higher likelihood of fires, explosions, traffic accidents, as well as production issues like equipment and process pipelines cracking due to freezing. Therefore, during winter, measures should be taken to prevent accidents caused by injuries, fires and explosions, as well as traffic accidents. It is also necessary to protect installations, pipelines, equipment, and valves from freezing and condensation, in order to ensure safe production during the cold winter months. Characteristics and hazards of safe production in winter: 1. The cold weather requires heavy clothing, which can affect a person’s hearing, vision, and mobility. Coupled with rainy and snowy conditions, this increases the risk of injuries such as frostbite and slips and falls. 2. Low temperatures can cause equipment and metal components to deform or crack, leading to leaks, explosions, fires, poisoning, and equipment production accidents. 3. During winter, when there is a cold high-pressure system, toxic and harmful gases tend to accumulate in large quantities. Coupled with the insulation measures used in winter, this can lead to poisoning and fire explosions. 4. In winter, when the air is dry, both humans as well as equipment and facilities are prone to generating static electricity, which can lead to fires, explosions, and injuries. Preventing personal injury: 1. Preventing frostbite – The company ensures that the production areas are properly heated, taking into account the local climate conditions, and also provides employees with personal protective equipment such as cotton coats and hats to keep them warm. Workers must wear the appropriate protective clothing as required at work; the collars and cuffs of cold-weather clothing should be fastened properly, and the straps of cold-weather safety helmets must be secured tightly. 2. Preventing slips and falls: The various stairs and pathways in production areas can freeze easily when exposed to rain or snow, which makes it easy for workers to slip and get injured while going up or down the stairs or walking on those paths. Therefore, it is important to clean away rainwater or snow from the stairs and pathways promptly, especially those on the equipment – as most of such stairs are made of steel frames, which increase the risk of falls and injuries. For outdoor work at heights, it is necessary to thoroughly inspect the equipment and facilities, and implement additional anti-slip measures. Those working at heights must keep their feet steady, hold onto the handrails firmly, and it is strictly prohibited to put hands in pockets or hold them behind the back while climbing up or down the ladder. 3. Prevention of poisoning and suffocation: Firstly, due to the cold weather in winter, the doors to the operation rooms in the plant area are usually kept tightly closed, which can lead to the accumulation of toxic gases such as carbon monoxide. Therefore, it is necessary to ensure regular ventilation. Second, strengthen the inspection of gas supply pipelines to prevent combustible gases from accumulating indoors. Third, strengthen safety education on poisoning prevention for employees, and popularize knowledge on self-rescue and seeking help. Accident Case | Violation of regulations led to the death of 3 people from carbon monoxide poisoning. A drilling team from a petroleum company was carrying out operations to relocate drilling rigs at the Tahe Oil Field in Xinjiang. Since the relocation was not completed that day, 4 people were assigned to stay at the old Ino camp. At around 11:30 on the 6th, three people who had stayed behind were found dead. The direct cause of the accident was that the people who stayed behind violated the rule stating that proper ventilation is necessary when people stay indoors to keep warm for extended periods; they improperly placed the unburned charcoal into abandoned buckets and brought them into the airtight camphouse to use as a heat source. Due to the lack of smoke exhaust facilities in the camping tents, carbon monoxide accumulated in large amounts, causing poisoning. To prevent fires and explosions: 1. Strengthen fire safety education for employees; in areas where flammable and explosive materials are present, strict control over hot work is necessary. The frequency of such operations should be reduced as much as possible. Hot work must be carried out only after following the proper procedures and having all necessary safety measures in place, including adequate fire prevention measures and supervision. 2. Strengthen routine inspections of the posts to prevent fires and **quality leaks. Wearing synthetic fiber clothing is prohibited in the plant area. Before carrying out tasks such as sampling from tanks, it is necessary to touch the anti-static devices to discharge any static electricity. 3. Do not use electric heating devices indiscriminately at work, and do not pull temporary wires. It is stipulated that electrical equipment should be used to prevent overload, and used electric heating devices must be turned off promptly to avoid fires caused by electricity use. 4. Ensure that fire protection facilities and equipment are complete, in good condition, and functional. After winter sets in, it is necessary to keep all such facilities and equipment in standby mode, while also taking measures to prevent freezing. Preventing traffic accidents: 1. Organize drivers to learn about the precautions for safe driving before winter arrives, and provide training on how to drive safely in adverse weather conditions such as extreme cold, strong winds, heavy fog, and blizzards. 2. Specific measures for anti-freezing, anti-skid, and anti-fogging should be established based on the type of vehicle and the characteristics of the tasks it performs. 3. Carry out seasonal maintenance on the vehicle by using lubricants and brake fluid suitable for winter conditions. Insulation covers should be installed around the engine and radiator housings to prevent heat loss. In particular, the braking system, steering system, and lighting system must be in good working order to ensure that the vehicle is in optimal condition. Conduct a thorough inspection and maintenance of the vehicle’s technical condition to keep it in good working order. 4. Replace the vehicle’s antifreeze, as well as engine oil and fuel of the appropriate grade, in a timely manner as required. 5. When driving on icy or snowy roads, it is necessary to control the speed carefully; high speeds should be avoided, as well as sudden turns and abrupt braking. It is also not allowed to accelerate or decelerate suddenly. On severely icy or snowy roads, anti-skid chains should be used. While driving, it is necessary to maintain a proper distance between vehicles, and to reduce speed accordingly in order to prevent rear-end collisions. Try not to dispatch long-distance vehicles in severe weather conditions such as ice, snow, and heavy fog. Preventing freezing and condensation of pipes and equipment valves in winter: 1. Pipes should make use of the fluid circulation within the system as much as possible to prevent freezing, thereby avoiding the need for additional temporary heating. For example, in a circulating cooling water system, when the equipment is shut down for a short period of time, the amount of circulating water in each condenser can be reduced appropriately while still maintaining circulation. For unavoidable dead zones, insulation or heat tracing should be used to prevent freezing. 2. Utilize drainage for anti-freezing purposes; for utility pipelines such as water, condensate, and steam, liquid accumulation and freezing may occur during shutdowns, so appropriate drainage, venting, and self-drainage mechanisms should be considered for anti-freezing. During parking or deactivation, these pipelines should be completely drained. Accident case – Inadequate treatment of circulating water in equipment during winter nearly caused damage to key equipment. A unit was shut down for maintenance in December; the operators on duty, preoccupied with dealing with urgent process issues, forgot to drain the water from one of the compressor cylinders. Additionally, due to long-term operation, some water lines in the system became clogged with sediment, resulting in poor performance of the circulating water system. This led to severe freezing inside the compressor cylinder, and the expansion caused the cylinder to bulge. Lessons from accidents: For equipment in the circulating water system that operates for extended periods of time, it is necessary to regularly check whether the circulation water system itself is functioning properly. After the equipment stops operating, the water inside it should be drained promptly to prevent damage due to freezing. 1. For pipelines that require anti-freezing protection, steam tracing and insulation should be used. The heating medium should be low-pressure steam, with a drain installed at the lowest point. All pipelines should, as much as possible, be designed for self-drainage, and the steam in the heat tracing pipes should flow downward. 2. Conduct a thorough inspection of the steam tracing for the instrument pipelines, and work together with the instrument technicians to ensure that the tracing pipelines are unobstructed, thereby preventing instruments equipped with interlock functions from being damaged by freezing and causing the plant to stop operating. Accident case – Failure to conduct timely semi-heating inspections of instruments led to partial shutdown of the plant. A chemical processing plant had been operating stably throughout the winter; comprehensive anti-freezing measures were taken on the equipment and facilities on site before winter arrived. However, since the instruments were under the responsibility of another department, no thorough inspection of their heating systems was carried out. One night, a sudden drop in temperature occurred; due to a malfunction in the heat-trapping steam traps at the pressure points associated with the circulating water system, the pressure gauges were damaged by freezing. The pressure rose to the interlock level, resulting in the complete shutdown of the circulating water system. Cause of the accident: The accident occurred due to insufficient and timely inspection of the instrument heating, particularly as comprehensive inspections were not carried out in a timely manner for instruments with interlock points. 1. Strengthen management by establishing records for anti-freezing and anti-condensation measures. 2. Strengthen winter patrol inspections; preventing freezing of pipelines, pumps, and instruments is a key focus. While ensuring energy conservation and emission reduction, it is necessary to prevent water accumulation, freezing, ice formation, or frost formation within the plant area. Areas that require special attention to prevent freezing: 1. All fire cannons must have their nozzles pointed downward, and the water inside them must be drained to prevent freezing damage ； Inspect and improve the exposed parts above ground of fire monitors and fire sprinkler pipelines, as well as the outdoor fire water lines for various production units. 2. In the tank area, it is necessary to check whether the static grounding facilities of each storage tank are intact, as well as whether the static bonding for the circulating water and medium pipelines that are prone to condensation is in good condition; all blind ends and dead corners should also be carefully inspected.