Fire prevention countermeasures for the technical

2022-08-08
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Fire prevention countermeasures for petrochemical units during technical transformation without shutdown

with the development of petrochemical production, the scale of petrochemical production unit transformation is becoming larger and larger. In order to maximize benefits, petrochemical enterprises usually carry out the transformation at the same time of full load production with the original equipment, which undoubtedly increases the fire risk factors, thus increasing the risk of fire

petrochemical production is a production with a high degree of automation, complex process flow, strong production continuity, a wide range of equipment and strict requirements for the control of various technical indicators. Moreover, most of the raw materials and products produced are flammable and explosive dangerous goods, and at the same time, they have the characteristics of high temperature, high pressure and cryogenic technology. It should be said that petrochemical production itself has a high fire risk. The transformation is carried out at the same time of the full load production of the device. Generally, new equipment and pipelines should be prefabricated or installed on site, and they should be connected at one time when the original equipment is shut down for overhaul. The transformation operation and production depth intersect, with long cycle, large quantities and high fire risk

I. affect process operation

1 Due to the need of transformation, some plant personnel came to the site to cooperate, which weakened the operation force to a certain extent

2. A large number of equipment and construction personnel are transported into the device, and a large number of hot works are carried out, which destroys the normal operating environment and affects the operation methods such as listening, touching, wiping, watching and comparing

3. The reconstruction period is long, the operator's mind is easy to be paralyzed, and there will be violations of discipline. The patrol inspection of fixed personnel, fixed routes, fixed contents, listing and pushing numbers cannot be implemented

4. The transformation operation can damage cables and instruments, so that the instrument interlocking cannot operate normally, and the process parameters cannot be accurately controlled. These can lead to misoperation or illegal operation, ranging from equipment damage and leakage to fire and explosion accidents

II. It is easy to cause medium leakage

1 The process operation is affected by the winding fixture, which will make the device system abnormal and lead to media leakage

2. When the construction personnel are working on the device in three-dimensional way, due to the lack of safety knowledge, weak judgment ability, lax labor discipline and low technical level, as well as the influence of high temperature, high pressure and cryogenic equipment, they will weld and cut the damaged equipment and pipelines, or the equipment and pipelines will be damaged by falling objects from high altitude, resulting in leakage. Due to the characteristics of chemical production, most of the leaked media are flammable and explosive substances. Once the media leaks, it is very easy to form explosive mixed gases. For example, the explosion limit of acetylene is 2.5% - 81%, and that of ethylene is 3.1% - 32%

III. a large number of ignition sources have been added

1 Welding and cutting fire source is required for transformation. According to the relevant domestic chemical safety technical regulations, vessels, equipment or pipelines with oil, pressure, and other flammable or toxic media are generally not allowed to carry out hot work. When it is really necessary, it shall be treated as special hot work. This controls the fire source in the production unit area. During the transformation of the new mode, the whole device is divided into each equipment and each pipeline for control, and special hot work may be carried out at each point. At the peak of reconstruction, dozens of electric welding and gas welding points in the device are operated at the same time

2. The transformation operation can produce new fire sources. Such as metal welding slag, sparks generated by friction and impact, high temperature or electric sparks generated by poor contact of electric welding circuit, electrostatic sparks of human body, sparks discharged by motor vehicles entering the device, etc. These ignition sources have large fluidity and strong concealment, which are difficult to find and control, and are enough to ignite the explosive gas mixture formed in case of leakage. For example, the impact spark energy is 1MJ (millijoules), the human electrostatic spark energy is more than 0.5mJ, while the acetylene gas volume is small, and the ignition energy is only 0.19mj, ethylene is 0.096mj, ethane is 0.26mj

3. Fire safety countermeasures for transformation petrochemical plant transformation has many risk factors, which has great fire risk. Only by aiming at the risk, comprehensively considering the role of both people and equipment, and implementing technical and management countermeasures, can hidden dangers be eliminated, fires be prevented, and the safety of transformation be ensured

first, establish a transformation organization, establish a device transformation headquarters, and bring production and transformation into unified command. The production and equipment directors of the enterprise are the chief and Deputy commanders respectively, and the directors of all functional departments are professional commanders. Clarify the safety responsibilities of each department, prepare the reconstruction construction plan and safety measures, and issue safety orders and relevant strengthened rules and regulations. At the same time, personnel from fire protection, safety, production, technology, equipment and electrical and other professional departments are transferred to form a transformation law enforcement team, and a group of strong hearted and experienced workers are transferred to form an on-site monitoring team

second, carry out fire safety education, make full use of blackboard newspapers, slogans and other forms, and repeatedly publicize relevant fire safety knowledge to employees. Carry out safety education for the employees and external construction personnel participating in the transformation in batches, and organize them to study the transformation safety order and relevant safety technical regulations. Sign the safety construction agreement with the construction unit to clarify the safety responsibilities, rewards and punishment methods. Doing these jobs well can enhance employees' awareness of fire prevention and improve their fire-fighting ability

IV. strengthen process operation

1 Ensure the operating environment. The construction shall be carried out in strict accordance with the scheme, and the normal process operation shall not be affected by the placement of unprepared equipment at the site, the erection of scaffolding, and hot work

2. Grasp the process and labor discipline. Adhere to the system of workshop leaders leading each shift. Strengthen the training and assessment of workers' process operation procedures, take the atomized fine powder rate (especially D50 7 micron fine powder output rate), fine powder yield and production capacity as the main technical indicators for major enterprises, control the operation steps and main technical indicators, "on the board" and "on the wall", grasp the process and labor discipline, and strictly enforce the process operation procedures. Strengthen the implementation of shift handover system and patrol inspection system

3. Use automatic control technology. Make full use of the advanced automatic control technology of the device to complete the production process. 7. The zigzag counting is to zigzag 90 degrees from the starting position to the right, and the process parameters are normally controlled to reduce human misoperation

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