Safety technical measures for emergency repair und

2022-08-01
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Safety technical measures for emergency repair under pressure

in the chemical industry, there are a large number of high-temperature and high-pressure, flammable, explosive, toxic and even highly toxic substances. For chemical enterprises with continuous production, emergency repair under pressure is inevitable, and it is also a technology for emergency repair construction in modern chemical production. If the treatment is reasonable and appropriate, production can be resumed as soon as possible to avoid losses. Otherwise, leakage points will be expanded, resulting in fire, explosion, poisoning and other accidents, endangering production, personal and property safety. Now we will communicate with our peers on the specific measures for emergency repair under pressure

I. risk factors in operation

1 Fire hazard

there are many combustible substances in chemical production, including H2, C0, CH4, C2H6, alkene, natural gas, water gas and other gases, organic solvents such as organic benzene, alcohol and ether, as well as other high molecular compounds, mixtures and other combustibles. When carrying out work on site, the existence of combustibles must be firmly remembered. For the three elements of combustion, i.e. combustibles, combustion supporting agents and fire sources, the conditions for blocking combustion, corresponding measures shall be taken for different substances through ventilation and water dilution to avoid combustion during operation

2. Danger of physical and chemical explosion

chemical explosion is divided into physical explosion and chemical explosion. Physical explosion refers to the sudden increase of internal pressure in the closed container and environment, and the pressure exceeds the mechanical strength of the container material. During high-pressure emergency repair, remember not to blindly carry out high-temperature heat treatment on the parts requiring plugging, and be sure to prevent the explosion caused by the increase of internal pressure caused by the thermal expansion of the medium in the container. Chemical explosion is an explosion caused by violent chemical reaction of active substances inside the equipment in a very short time. The formation of chemical explosion also requires three conditions: first, there are flammable and explosive substances; Second, the mixture of combustible materials and air reaches the explosion limit; Third, there is a fire source. Chemical explosion is dangerous and easy to cause interlocking reaction. Therefore, attention must be paid to prevent chemical explosion. The above three conditions must be prevented from coexisting. Therefore, measures such as ventilation and heat reduction, anti-static, and no open fire can be taken during high-voltage emergency repair and plugging

3. Poisoning risk

countless substances can cause harm to human body. Especially in the emergency repair and plugging construction, various toxic gases include Cl2, SO2, NH3, C0, C2H2, H2S, HF, F2, etc. the closer the operators are to them, the greater the possibility of inhalation. Therefore, during the operation, measures such as strengthening supervision, personnel rotation operation and construction, ventilation at the operation site, personnel in the upper wind position, and wearing complete protective articles should be taken, For some toxic, flammable and explosive gases such as CO, H2, H2S, etc., it is necessary to prevent poison, fire and static electricity

4. Risk of radiation damage

the a.7 tensile strength test method of radiation is very damaged, affecting people's respiratory tract, digestive tract, mouth, skin and other parts. The radiation inside the human body is the most harmful, followed by radiation. There may be many kinds of radiation at the same site at the same time, so as to prevent the damage of radiation. In the emergency repair and plugging site, it is necessary to wear protective articles and set effective radiation barriers to prevent the damage and inhalation of radioactive smoke

5. Scald, frostbite and burn risk

in the emergency repair construction, the human body is easy to be in close contact with the medium, so the construction personnel and the supervisor must cooperate well to prevent scald, frostbite and burn

II. Safety appliances for emergency repair under pressure

1 Gas masks and fire-fighting appliances

there are two types of gas masks: filter type and isolation type. Filter type masks are only applicable to places where the concentration of toxic substances in the air is less than 2% and the oxygen content is greater than 16%. The chemicals in the canister should match different components. The isolating mask is suitable for various occasions

the site shall be equipped with wet cotton mats, asbestos mats, dry powder fire extinguishers, fire pipelines and other fire-fighting appliances

2. Protective clothing, gloves, shoes, socks, ointments, etc.

different protective articles shall be selected according to different operation conditions to prevent water, oil, gas, corrosion, dust, etc. For pressure construction, it is best to wear the integrated clothing. You are like in the remote cities of Xinjiang, but the freight is relatively expensive, so you can achieve good sealing; Protective ointment is mainly used to protect the skin and has the functions of anti-virus and anti freezing

3. Masks, glasses, etc.

masks are classified into dust-proof and gas-proof types, which must be selected accurately according to the operation conditions; Glasses should be appropriate and sealed to protect eyes

4. Safety belts and safety ropes

safety belts must be used for high-altitude operation to prevent falling. Safety ropes are used in hazardous operation areas for rescue

III. specific safety measures

in order to ensure the safety of high-pressure emergency repair and plugging, reduce system shutdown and reduce various wastes, the following safety measures should be paid attention to in the construction process:

(1) strictly implement the safety and anti-corrosion measures such as fire prevention, explosion-proof, poison prevention and corrosion prevention:

(2) wear labor protection articles suitable for the operation conditions in strict accordance with the regulations, and prepare the required safety appliances and equipment

(3) select construction personnel. Select young and energetic personnel who are intentional, have rich practical experience and are familiar with the working conditions of the equipment, and allocate 1~2 intentional guardians, with fewer and capable personnel

(4) clean up the plugging site, and take protective and isolation measures such as ventilation, evacuation, drainage, dilution and covering for hazardous media according to their physical and chemical properties

(5) for the leakage stoppage and emergency repair of flammable and explosive media, generally speaking, the welding leakage stoppage shall be avoided as much as possible, and the clamp method shall be used. It is not allowed to use tools and operation methods that may cause sparks. Copper tools shall be used, and electrical equipment and tools shall not be used

(6) for the nut that has not been disassembled for a long time, the bolt shall be cleaned with rust remover first, and the lubricating oil shall be applied to the screw waste. The action shall be light to avoid the collision between tools and equipment:

(7) for underwater work, waterproof protective clothing shall be worn to ensure smooth information and prevent underwater electric leakage. Work in limited space such as indoor trench, underground and container shall be protected against poison and asphyxiation. The hardness of steel hammer hole and adjacent parts of hammer hole shall be equipped with complete rescue measures, and the gas composition in the workplace shall be analyzed in a timely and rapid manner. In case of emergency, rescue measures shall be taken quickly

(8) platforms and lifts shall be set up for high-altitude operation, and operators shall wear safety belts and helmets

(9) operators should be cautious and decisive, look at it while doing it, and contact the supervisor in time when finding the same problem to jointly solve the problem. It is strictly prohibited to act rashly

IV. on site management of emergency repair and plugging

there must be a unified command organization on the operation site, the personnel work should be in order, and the items should be arranged in order according to the use conditions to avoid random running of personnel and disorderly items: unified leadership, clear division of labor and mutual coordination should be conducted during the construction process; According to the actual situation, the leakage stoppers, supervisors and firefighters shall be arranged, and the workshop process personnel shall cooperate with the emergency repair; Strict personnel management shall be carried out during site construction. Except for maintenance personnel and supervision personnel, other personnel shall stand outside the warning line and be on standby. Maintenance personnel shall carry out maintenance according to the operating procedures, and report new situations to the site commander in time, so as to take measures in time; All leakage locations are weak places with poor pressure bearing capacity. The action must be light and not reckless, so as to avoid expanding the leakage point and forcing the system to stop, resulting in huge losses

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