Safety measures and emergency disposal principles

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Safety measures and emergency disposal principles for hazardous chemicals - ammonia is a colorless gas with strong pungent odor under normal temperature and pressure. It can be liquefied at 20 ℃ and 891kpa, and release a large amount of heat. When the temperature of liquid ammonia changes, the coefficient of volume change is very large. Soluble in water, ethanol and ether. The molecular weight is 17.03, the melting point is -77.7 ℃, the boiling point is -33.5 ℃, the gas density is 0.7708g/l, the relative vapor density (air = 1) is 0.59, the relative density (water = 1) is 0.7 (-33 ℃), the critical pressure is 11.40mpa, the critical temperature is 132.5 ℃, the saturated vapor pressure is 1013kpa (26 ℃), the explosion limit is 15% ~ 30.2% (volume ratio), the spontaneous combustion temperature is 630 ℃, and the maximum explosion pressure is 0.580mpa

main uses: mainly used as a refrigerant and to prepare ammonium salt and nitrogen fertilizer

[health hazards]

has strong irritation and corrosion effect on the mucous membrane of eyes and respiratory tract. Acute ammonia poisoning may cause eye and respiratory tract irritation, bronchitis or peribronchitis, pneumonia, and toxic pulmonary edema in severe poisoning. High concentration ammonia can cause reflex respiration and cardiac arrest. May cause eye and skin burns

pc-twa (time weighted average allowable concentration) (mg/m3): 20; Pc-stel (allowable concentration for short time exposure) (mg/m3): 30

[General requirements]

operators must receive special training, strictly abide by the operating procedures, master the operating skills and have the knowledge of emergency disposal

it shall be strictly sealed to prevent leakage. The workplace shall be provided with adequate local exhaust and overall ventilation, away from fire and heat sources. Smoking is strictly prohibited in the workplace

ammonia leakage detection and alarm devices shall be set up in ammonia production and use workshops and ammonia storage sites, explosion-proof ventilation systems and equipment shall be used, and at least two sets of positive pressure air respirators, long tube gas masks, heavy protective clothing and other protective equipment shall be equipped. Wear chemical safety glasses, anti-static work clothes and rubber gloves. When the concentration in the workplace exceeds the standard, operators should wear filter gas masks. Prevent frostbite when liquid contact is possible

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, and shall be equipped with interlocks between rectifier devices and press, power supply, pipeline pressure, ventilation facilities or corresponding absorption devices. Key storage tanks shall be equipped with emergency cut-off devices

5. This product can be widely used in aerospace, petrochemical, auto parts, engineering plastics, wires and cables

avoid contact with oxidants, acids and halogens

safety warning signs shall be set in production and storage areas. During transportation, the steel cylinder and container must be grounded and jumpered to prevent static electricity. Handle with care to prevent damage to the cylinder and accessories. It is forbidden to use the electromagnetic crane, tie it with chain rope, or use the bottle valve as the lifting force point. Fire fighting equipment and leakage emergency treatment equipment of corresponding varieties and quantities shall be provided

[special requirements]

[operation safety]

(1) it is strictly prohibited to use ammonia pipeline as welding grounding wire. It is forbidden to knock the pipe and valve body with iron tools to avoid sparks

(2) the following protective measures shall be taken for operation in the environment containing ammonia:

corresponding ammonia detectors and protective devices shall be equipped according to different operating environments, and personnel management shall be implemented to keep the ammonia detectors and protective devices D. devices with strong graphic operation functions in standby status

wind vane shall be set in the operation environment

the air compressor of the air supply unit shall be placed on the windward side

carry ammonia gas detector and positive pressure air respirator during overhaul and emergency repair

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

[storage safety]

(1) store in a cool and ventilated special warehouse. Keep away from fire and heat source. The warehouse temperature should not exceed 30 ℃

but for some new materials and special materials, they should be stored separately from oxidants, acids, halogens and edible chemicals. Do not mix them. The storage tank shall be kept away from fire and heat source. Explosion proof lighting and ventilation facilities shall be adopted. It is forbidden to use mechanical equipment and tools that are easy to produce sparks. The storage area shall be equipped with leakage emergency treatment equipment

(3) the liquid ammonia cylinder shall be placed at least 5m away from the work site and well ventilated

(4) pay attention to lightning protection and anti-static. The ammonia storage tank in the plant (workshop) shall be equipped with lightning protection and anti-static facilities according to the provisions of code for design of lightning protection of buildings (GB 50057)

[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) special tank car 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; Protect from 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. It is not allowed to mix and load objects with conflicting nature with the vehicle and give a lift to irrelevant personnel. 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 the vehicle to a safe place to put out the fire or stop the leakage

(4) the pipeline conveying ammonia shall not be laid close to the heat source; When the 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; When ammonia pipeline is laid overhead, the pipeline shall be laid on the support or trestle of non combustible body. Under the laid ammonia pipeline, it is not allowed to build buildings irrelevant to the ammonia pipeline and stack inflammables; The outer wall color and mark of ammonia pipeline shall comply with the basic identification color, identification symbol and safety mark of industrial pipeline (GB 7231)

[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: remove contaminated clothes immediately and wash thoroughly with 2% boric acid solution or a large amount of clean water. Seek medical attention

eye contact: lift the eyelid immediately, and make sure that the specified friction coefficient should be thoroughly washed with a large amount of flowing water or normal saline for at least 15 minutes after repeated experiments. Seek medical attention

[fire extinguishing method]

firefighters must wear full body fire and poison proof clothing to extinguish the fire in the upwind direction. Cut off the air supply. 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, insoluble foam, carbon dioxide, sand

[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 fully enclosed chemical protective clothing with built-in positive pressure self-contained air respirator. In case of liquefied gas leakage, pay attention to antifreeze damage. Do not touch or cross the leakage. Cut off the source of leakage as far as possible. Prevent gas diffusion through sewers, ventilation systems and confined spaces. If it is possible to turn the container over so that gas rather than liquid escapes. Construct a dike or dig a pit to contain liquid leakage. Neutralize with acetic acid or other dilute acids. It can also be diluted and dissolved with spray water, while building a dike or digging a pit to receive a large amount of wastewater. If possible, send the residual gas or leakage gas to the water washing tower or the fume hood connected to the tower by exhaust fan. If the cylinder leaks, it can be immersed in water when it cannot be blocked. It is better to set water or dilute acid spraying facilities in the storage tank area. Isolate the leakage area until the gas is exhausted. Gas leakage containers shall be properly handled and reused after repair and inspection

isolation and evacuation distance: small amount of leakage, initial isolation of 30m, downwind evacuation of 100m in the day and 200m at night; Large amount of leakage, initial isolation of 150m, downwind evacuation of 800m during the day and 2300m at night

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