Safety measures and emergency disposal principles

2022-07-29
  • Detail

Safety measures and emergency disposal principles for hazardous chemicals - ethylene is a colorless gas with sweet taste. Insoluble in water, slightly soluble in ethanol, soluble in ether, acetone and benzene. Molecular weight 28.05, melting point -169.4 ℃, boiling point -103.9 ℃, gas density 1.260g/l, relative density (water =1) 0.61, relative vapor density (air =1) 0.98, critical pressure 5.04mpa, critical temperature 9.2 ℃, saturated vapor pressure 8100kpa (15 ℃), explosion limit 2.7% ~ 36.0% (volume ratio), spontaneous combustion temperature 425 ℃, minimum ignition energy 0.096mj

main uses: mainly used for making polyethylene, polyvinyl chloride, acetic acid, etc

[combustion and explosion risk]

extremely flammable, can form explosive mixture when mixed with air, and may cause combustion and explosion in case of open fire, high heat or contact with oxidant

[active reaction]

severe chemical reaction will occur in contact with fluorine, chlorine, etc

[health hazards]

has strong anesthetic effect

acute poisoning: inhalation of high concentration ethylene can immediately cause loss of consciousness, and liquid ethylene can cause skin frostbite

chronic effects: long-term exposure may cause dizziness, general discomfort, fatigue and inattention

[General requirements]

the operators must be specially trained. Only one card can be played in the paper mill due to the shortage of raw materials. Strictly abide by the operating procedures, master the operating skills and have the knowledge of emergency disposal

closed operation, strict prevention of leakage, and comprehensive ventilation in the workplace

the production, use and storage sites shall be equipped with leakage detection and alarm devices, and explosion-proof ventilation systems and equipment shall be used. Keep away from fire and heat sources. Smoking is strictly prohibited in the workplace. Operators should wear anti-static work clothes

pressure vessels and equipment such as storage tanks shall be equipped with safety valves, pressure gauges, liquid level gauges and thermometers, and shall be equipped with safety devices with pressure, liquid level and temperature remote transmission records and alarm functions. Input and output pipelines shall be equipped with emergency cut-off devices

avoid contact with oxidants and halogens

safety warning signs shall be set in production and storage areas. Handle with care to prevent damage to the cylinder and accessories. During transportation, the steel cylinder and container must be grounded and jumpered to prevent static electricity. Fire fighting equipment and leakage emergency treatment equipment of corresponding varieties and quantities shall be provided

[special requirements]

[operation safety]

(1) the ethylene concentration in the ethylene workplace must be measured regularly and published on site in time

(2) in the production area, open fire and operations that may produce open fire and sparks are strictly prohibited (the fixed hot work area must be more than 30m away from the production area). If hot work is required during production or maintenance, the approval procedures for hot work must be handled. Ethylene equipment, vessels and pipelines shall be purged with nitrogen before major and minor repairs with hot work. The purity of nitrogen used shall be greater than 98%. Only when the ethylene content at the purging port is less than 0.5% can hot work be carried out for repair. The approval of relevant departments shall be obtained in advance. Special personnel shall be assigned to monitor and take necessary fire and explosion prevention measures

(3) when ethylene pipes, valves and water sealing devices are frozen, they can only be thawed by heating with hot water or steam. It is strictly prohibited to bake with open fire. During the operation of ethylene system, it is not allowed to knock, repair and fasten under pressure, overpressure and negative pressure

(4) when filling, use the universal joint pipe filling system to prevent overfilling

[storage safety]

(1) storage containers shall have correct identification. Keep the container closed and store it in a cool and ventilated warehouse dedicated to flammable gas. The warehouse temperature should not exceed 30 ℃

(2) keep away from heat source, ignition source, acid, halogen and oxidant. The circuit in the storage area must be grounded to avoid electric sparks. Explosion proof lighting and ventilation facilities shall be used. It is forbidden to use mechanical equipment and tools that are easy to produce sparks

(3) the distance between the ethylene cylinder and the containers and cylinders containing flammable, explosive, combustible substances and oxidizing gases shall not be less than 8m; The distance from the air-conditioning unit, air compressor, ventilation equipment and other air intakes shall not be less than 20m; The distance from open fire or common electrical equipment shall not be less than 10m

(4) for the storage tank, the safety valve, liquid level gauge, pressure gauge, etc. shall be calibrated regularly, and the pressure test shall be carried out for the storage tank regularly according to the standard requirements. At the same time, a system test shall be carried out for the corrosion of the tank wall

(5) pay attention to lightning protection and anti-static. The storage tanks in the plant (workshop) shall be equipped with lightning protection facilities in accordance with the code for design of lightning protection of buildings (GB 50057)

(6) the storage area shall be equipped with a gas detector to detect the leakage of materials in time and take measures. The storage area shall be equipped with leakage emergency treatment equipment

[Transport Safety]

(1) transport vehicles shall be equipped with dangerous goods transport signs and satellite positioning devices with driving record function. Without the approval of the public security organ, transport vehicles are not allowed to enter the restricted areas for transport vehicles of hazardous chemicals

(2 for materials with extremely high hardness (such as cemented carbide, etc.)) special tank cars shall be used for transportation. The flame arrester (spark arrester) installed on the tank car must be intact. The tank car and transport truck shall be equipped with static conductive towing line; More than 2 dry powder or carbon dioxide fire extinguishers and explosion-proof tools shall be provided on the tank car; Sunshade measures shall be taken to prevent direct sunlight

(3) when the vehicle transports the steel cylinders, the bottle mouth shall all face the right side of the vehicle driving direction, the stacking height shall not exceed the protective fence of the vehicle, and the triangular wood cushion shall be used to clamp them to prevent rolling. When the cylinders are discharged vertically, the height of the carriage shall not be less than 2/3 of the cylinder height. Keep away from kindling during transportation. It is not allowed to park at the place with open fire or in the area with many people. Someone should take care of the parking. In case of leakage or fire, drive to a safe place to put out the fire or stop the leakage

(4) attention shall be paid to the following matters when ethylene is transported by pipeline:

gas transmission pipeline shall not pass through urban water sources, airports, military facilities, stations and wharves. In case of unavoidable conditions, protective measures shall be taken and approved by relevant national departments

mileage piles, corner piles, sign piles and test piles shall be set along the gas transmission pipeline

when the gas transmission pipeline is laid on the ground, protective measures shall be taken and obvious warning signs shall be set in the sections where there are many activities of people and are easy to be hit by vehicles and foreign objects; Ethylene pipes shall be laid on supports or Trestles of non combustible materials. Under the laid pipeline, it is not allowed to build buildings irrelevant to the pipeline and stack inflammables

the management unit of gas transmission pipeline shall assign special personnel to inspect the pipeline regularly and deal with the abnormal conditions along the gas transmission pipeline in time

[first aid measures]

inhalation: quickly leave the site to a place with fresh air. Keep respiratory tract unobstructed. If breathing is difficult, give oxygen. If breathing stops, give artificial respiration immediately. Seek medical attention

skin contact: in case of frostbite: soak the affected part in warm water maintained at 38 ~ 42 ℃. Do not smear. Do not use hot water or radiant heat. Use clean conch profiles to build a 40000 ton/a plastic floor technical transformation project and dry dressing. If you feel unwell, see a doctor

[fire extinguishing method]

cut off the air source. If the air source cannot be cut off, it is not allowed to extinguish the flame at the leakage. Spray water to cool the container, and move the container from the fire site to an open place as far as possible

extinguishing agent: mist water, foam, carbon dioxide, dry powder

[leakage emergency treatment]

eliminate all ignition sources. The warning area shall be delimited according to the area affected by the gas, and irrelevant personnel shall evacuate to the safety area from the crosswind and upwind. It is recommended that emergency treatment personnel wear positive pressure self-contained air respirators and anti-static clothing. All equipment used in the operation shall be grounded. Prevent frostbite when exposed to liquids. Do not touch or cross the leakage. Cut off the source of leakage as far as possible. If it is possible to turn the container over so that gas rather than liquid escapes. Spray water restrains steam or changes the flow direction of steam cloud to avoid water contact with leakage. Do not use water to directly impact the leakage or leakage source. Prevent gas diffusion through sewers, ventilation systems and confined spaces. Isolate the leakage area until the gas is exhausted

as an emergency preventive measure, the leakage isolation distance shall be at least 100m. In case of massive leakage, the initial evacuation distance in the downwind direction shall be at least 800m

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