To ensure the safety of device design, it is necessary to strictly and correctly comply with government regulations and standards (especially mandatory standards). What else should designers do?

Dangerous factors of the device

There are many types of petrochemical equipment, and due to differences in technical routes, raw materials, products, and process conditions, the hazardous factors that exist are not the same. They can be roughly summarized as follows:

1. Poisoning hazard

In the process of petrochemical production, occupational exposure to toxic substances in the form of raw materials, finished products, semi-finished products, intermediates, reaction by-products, and impurities can cause pathological changes in human physiological functions and normal structures through the mouth, nose, and skin during operation. This can disrupt normal human reactions, reduce the ability of people to make correct judgments and take appropriate measures in production, and even lead to death.

2 Fire and explosion hazards

A mixture of combustible gases, oil and gas, dust, and air, when its concentration reaches the explosive limit, can ignite and cause a fire or explosion. The radiation heat of the fire and the shock wave generated by the explosion may cause harm and damage to people, equipment, and buildings. Especially the steam cloud explosion formed by a large amount of combustible gas or oil and gas leakage is often destructive. There are many examples such as the explosion of the ethylene air separation unit of Fushun Petrochemical Company in 2001, the explosion of the high-pressure polyethylene unit of Beijing Yanshan Petrochemical in 2000, and the hydrogen explosion of the high-pressure hydrogenation unit of Daqing Petrochemical Company in 1967, all of which resulted in significant losses.

3 Reactive hazards

Chemical reaction processes can be divided into two categories: endothermic and exothermic. Usually, exothermic reactions are more dangerous than endothermic reactions, especially those involving the use of strong oxidants; The halogenation reaction of introducing halogen atoms into organic molecules.

4 Negative pressure operation

Negative pressure operation can easily allow air and moisture to enter the system, or form explosive gas mixtures, or cause dangerous reactions to oxygen and water sensitive materials due to oxygen and water vapor in the air, such as the vacuum tower system in the atmospheric and vacuum distillation unit of oil refining.

5. High temperature operation

The operating temperature of flammable liquids exceeds their flash point or boiling point, and once leaked, it will form explosive oil and gas vapor clouds; The operating temperature of flammable liquids is equal to or exceeds their self ignition point, and once leaked, they can spontaneously ignite or become a source of ignition; High temperature surfaces are also a source of ignition, and splashing flammable liquids onto them may cause a fire.

6. Low temperature operation

Not designed for low-temperature conditions, due to the intrusion of low-temperature media, equipment and pipelines may experience low-temperature brittle failure. Damage to low-temperature equipment in air separation, and low-temperature brittle fracture at -195 ℃ in the low-temperature methanol washing process of large fertilizer residue gasification.

7 Corrosion

Corrosion is a common factor leading to equipment and pipeline damage causing fires. The importance of the corrosion resistance of materials is second only to their mechanical properties in terms of material optimization performance. Their corrosion resistance is mostly based on experience and testing, and there is no standard to follow (Sinopec's equipment for processing high sulfur oil has current standards for material selection). In addition, the diversity of corrosion types and the ever-changing environmental conditions have increased the unpredictability of corrosion hazards.

1.8 Leakage

Leakage is an important pathway for the release of hazardous media from equipment pipelines into the atmosphere. Failure of static and dynamic seals in equipment pipelines, especially due to temperature and pressure fluctuations, as well as conditions of permeable corrosive media, can easily lead to seal failure. Weak links on equipment pipelines, such as bellows expansion joints, glass level gauges, and the failure of dynamic seals in moving equipment, can cause serious accidents once damaged.

1.9 Fire source

A 0.5mm long arc or spark can ignite hydrogen gas. Installation of open flame heating equipment (heating furnace), high temperature surfaces, and possible electric arcs, static sparks, impact friction sparks, chimney flame energy are all sufficient to ignite explosive mixtures.

Diphenyl ether manufacturer