Previous compressor combustion and explosion accidents and compressor mechanical accidents

combustion and explosion accidents

In chemical and petrochemical production, compressor combustion and explosion accidents are extremely dangerous. They not only seriously affect safe and stable production and cause extremely serious economic losses, but also cause casualties and damage to buildings. Therefore, compressor combustion and explosion accidents have attracted great attention.
The compressed medium used in petrochemical compressors is mostly flammable and explosive gas, which is extremely prone to leakage under high pressure. Combustible gas leaks through defects such as cylinder joints, intake and exhaust valves, flanges, welds, and seals on equipment and pipelines. Fatigue and fracture of compressor components can cause high-pressure gas to escape into the factory. Air can also enter the compressor system, forming an explosive mixture. If improper operation, maintenance, or overhaul is performed, the mixture of flammable gas and air, reaching the explosive limit, can combust violently upon contact with a fire source, potentially causing an explosion.

In oxygen compressors, if the oxygen flow is mixed with flammable gases, grease, rust, paper scraps, and other impurities and metal objects, and the lubricant is suddenly interrupted or insufficiently supplied, it can cause "dry grinding" of the cylinder, leading to high temperatures. Under the high pressure and high temperature, the combustible materials in the cylinder quickly react with the oxygen, causing spontaneous combustion. The accumulation of heat and the combustion-supporting effect of the high-pressure oxygen can intensify the combustion, resulting in extremely serious cylinder combustion and explosion accidents.
Cylinder lubrication for petrochemical compressors and air compressors is typically done with mineral oil, a flammable substance. When the gas temperature rises dramatically, exceeding the lubricant's flash point, intense oxidation occurs, posing a risk of combustion and explosion. Furthermore, suspended lubricant molecules, under high temperature and pressure, readily react with oxygen in the air. This is particularly true in the oil film adhering to the hot metal surfaces of exhaust valves and exhaust pipes, where oxidation is exacerbated, generating acids, asphalt, and other compounds. These compounds combine with dust in the gas and metal particles generated by mechanical friction, depositing as carbon deposits in the cylinder head, piston ring grooves, valves, exhaust pipes, surge tanks, oil-water separators, and gas tanks.

Carbon deposits are flammable and can spontaneously combust or even explode under conditions such as high temperature overheating, accidental mechanical impact, air flow shock, electrical short circuits, external fires, and static sparks. Combustion of carbon deposits produces large amounts of CO. When the CO content in the compressor system reaches 15% to 75%, an explosion can occur, releasing a large amount of heat and generating a powerful shock wave. Due to the rapid increase in gas pressure and temperature and the rapid expansion of the combustion products, the shock wave propagates at supersonic speeds along the compressed gas flow direction, causing multiple, continuous explosions.

During the startup of the compressor, the air in the compressor system is not replaced with inert gas or the replacement is incomplete (the oxygen content exceeds 4% or there are residual combustible impurities) before startup; due to lack of operating knowledge, the outlet valve and bypass valve of the compressor (or ice machine) are not opened, causing overpressure; during operation, the instrumentation of the compressor gas regulation system fails, causing the gas pressure to be too high, etc., which will cause combustion and explosion accidents.