1.Serious leakage of flammable gas
(1) The suction and exhaust valves failed, resulting in loose seals and leaks, which caused fires and explosions.
(2) Severe leaks at the shaft seal caused fires.
(3) Leaks at the valve flange connected to the high-pressure synthesis system caused a short circuit at the lighting joint, causing fires and explosions. Leaks at the base of the pressure gauge at the outlet of the circulating machine caused high-pressure gas to burst out, resulting in static electricity causing fires and explosions. The cylinder support of the nitrogen and hydrogen compressor broke, causing leaks in the inlet pipe, which caused explosions when exposed to open flames.
Precautions:
(1) Arrange the suction and exhaust valves properly to ensure the flexibility and airtightness of the valves, and clean the dirt and replace the valves in time.
(2) Install the piston rod and packing properly, check the wear regularly, and replace the packing in time. The turbine oxygen compressor should be equipped with an airtight device to flow the safety sealing gas into the shaft seal part, and set up a regulating device to maintain the pressure difference with the balance chamber.
(3) Pipes, valves, flanges, instruments and other pipe fittings should be installed properly to ensure that the joints are sealed reliably, and check the joints for air leakage regularly. Set up a gas leakage detection device to monitor abnormal phenomena in the sealing system.
2.Combustible gas is ejected due to corrosion and fatigue fracture
(1) The vent pipe at the outlet of the circulating machine fractured due to fatigue, causing ammonia leakage and fire and explosion.
(2) The thread roots of the connecting bolts between the multi-stage cylinders and between the cylinder and the machine body fractured due to fatigue, causing a large amount of high-pressure gas to be ejected, causing fire and explosion.
(3) Damage to the machine body and high-pressure cylinder caused the oil system to catch fire. The cylinder liner material was poor, and the cylinder body had serious shrinkage defects, which caused fatigue fracture, causing high-pressure gas to rush out and cause space explosion.
(4) The thread roots of the piston lock nut and the thread roots of the piston rod and piston connection fractured due to fatigue, causing the piston rod to hit and catch fire, causing explosion.
Preventive measures:
(1) Reduce vibration of the compressor piping system and ensure the quality of pipes and welds.
(2) Ensure that the connecting bolt structure and geometric dimensions are reasonable and the material is of high quality, and improve the strength and processing accuracy of the thread; ensure that the connection surface is tightly fitted and the tightening force is appropriate.
(3) Strictly carry out quality inspections of the fuselage, cylinder block, and cylinder liner; diagnose the remaining life of the main components of high-temperature and high-pressure compressors.
(4) Improve the quality of the heat treatment process to ensure the strength of the piston rod; use arc rolling to improve the processing accuracy of the thread; ensure high quality during manufacturing and installation to avoid the generation of additional bending moments.
3.The temperature and pressure are too high, carbon deposits are flammable and combustibles burn.
(1)Improper selection of cylinder lubricant, mismatch of lubricating oil brand, excessive or insufficient oil filling, poor oil quality, causing a sharp rise in gas temperature and the formation of carbon deposits.
(2) Poor circulating cooling water quality, poor intercooling effect, and unexpected interruption of cooling water, causing the gas temperature to rise. Failure to drain oil and water from the intercooler, oil-water separator, and gas storage tank in a timely or incomplete manner increases dirt and resistance, causing the gas temperature to rise.
(3) Using air pressure testing to test for leaks, carbon deposits at high temperatures, violent oxidation, and explosions; impurities such as rust are not completely removed during the mechanical manufacturing process, causing heat; the filter is severely fouled, the inhaled gas contains a large amount of dust, and carbon deposits are easily formed.
(4) Lack of safety measures and modern management methods.
Preventive measures:
(1)Select lubricants according to the properties of the gas. For acetylene, use non-emulsified mineral oil; for chlorine, use concentrated sulfuric acid; for oxygen, use distilled water and diluted glycerin; for ethylene, use white oil or oil-free lubrication. Select high-grade grease with a high flash point and low carbon deposition after oxidation. The oil injection amount should be appropriate. For a piston moving area of 200 cm2/min, the oil injection amount should be about 0.01 L/h. Regularly analyze the oil quality and replace the oil in time.
(2）Adopt advanced water treatment technology, regularly remove dirt and discharge oil and water, and strictly control the exhaust temperature, which must not exceed the allowable value.
(2)Thoroughly remove foreign matter and rust from castings and piping, and thoroughly blow down the entire compressor system after assembly. Select corrosion-resistant materials, high-efficiency filters, and remove dirt in time.
(4) Install explosion-proof walls and inert gas fire extinguishing devices near compressors with explosive gases. The reliability of safety valves for high-pressure, flammable and explosive gases should be checked regularly. Use instrumentation and automatic alarm devices so that safety measures can be taken in time when abnormal faults are found.
4.Misoperation and illegal operation lead to combustion and explosion
(1) When inspecting the nitrogen and hydrogen compressor, aluminum plates were used as blind plates, causing high-pressure gas to spurt out and cause a space explosion. When the ice machine was started, the bypass valve and outlet valve were not opened, causing the pressure to exceed the material strength limit and cause an explosion. During the operation of the blower, abnormal noises were detected but the blower was not stopped and inspected in time, causing the blower shaft neck to break and the oil tank to catch fire and explode.
(3)During the load test of the chemical compressor, low-pressure nitrogen was not used for purging or the purging was incomplete, causing combustion and explosion.
(4)The oil ban treatment was not thorough, causing the packing to catch fire with oil and the oil collection tank to explode.
(5) It was mistakenly believed that there was no liquid ammonia at the outlet of the ice machine section; when the liquid hammer sound was heard, no drainage treatment was performed and a shortcut valve was used, causing the liquid ammonia to vaporize due to the high temperature and cause an explosion.
Preventive measures
(1)Be familiar with the operating knowledge. Before starting, the outlet valve of the compressor (or ice machine) must be opened. After starting, pay close attention to the changes in the pressure and temperature of water, gas, and oil, as well as abnormal sounds.
(2)Load test: When starting the flammable gas compressor, first replace the air in it with inert gas to reduce the oxygen content to less than 4%. For compressed hydrogen and acetylene gas, the maximum oxygen content is 2%. The load test must be carried out strictly in accordance with the operating procedures.
(3)It is prohibited to use gasoline or other volatile oils to clean parts. During the manufacturing and installation process, try to avoid contact with the atmosphere. Strictly implement oil-free treatment and control oil temperature.
(4) Operate carefully.
5.Explosions caused by manufacturing defects and poor management
(1) Damage to the oxygen compressor outlet valve causes overpressure, triggering the safety valve and causing a fire and explosion; explosion of the oil-water separator due to manufacturing defects; and explosion of the buffer due to water in the buffer during operation.
(2)Excessive pressure during operation damages the water seal, causing a large amount of high-pressure gas to be released, and igniting the spark.
(3)Due to a power outage, the decompression gas of the propylene gas compressor overflows. When restarting, the relay generates sparks, causing a space explosion.
(4)Aging of the motor insulation causes a fire and burns the compressor.
Preventive measures
(1) Strengthen quality management and quality inspections, and promptly remedy or replace vulnerable parts when defects are discovered.
(2) Pay close attention to changes in pressure gauge readings.
(3) Strengthen the maintenance and care of motor relays.
(4) Replace motors with aging insulation in a timely manner.
