Liquefied gas leak

If the heat exchanger is not over-pressured, the leakage is generally not large, and it can be dealt with by tightening the bolts. I have experienced this twice.: Once, due to a problem with the stabilized liquefied gas dehydration valve, static electricity leaked and caught fire, injuring two people and making the entire stable area miserable. The second time, the dehydration valve of the refined liquefied gas coalescer froze. Workers opened the valve too large and could not control it after degassing. One person suffered frostbite and the whole device was covered with white mist. There was a thick layer on the ground. Fortunately, there was no fire or explosion.

I have seen a serious leak. A layer of white mist accumulated underground. Finally, it was blown with steam.

More than ten years ago, I encountered an incident where the interface indicator of the dehydration tank failed and the entire installation area was filled with white mist. There were no flammable gas alarms at that time, but luckily there was no flash explosion. :L

When our installation was first started a few years ago, the glass plate level gauge of the liquefied gas tank broke and a large amount of liquefied gas leaked. Fortunately, there was no flash explosion. The level gauge was cut off in time and dispersed with steam. At that time, martial law was enforced for several kilometers. It was really scary to think about it. As for the heat exchanger flange, I haven't heard of it leaking. It seems that the catalytic device of Dalian No. 7 Plant exploded due to a leak of liquefied gas, and the entire device was destroyed. :funk:

Mass leakage handling: Don’t be afraid when faced with danger, take action when it’s time to take action 1. Immediately report to dispatch and contact the fire department and other relevant departments 2. Turn off mobile phones and walkie-talkies on site, stop work if necessary, carry a respirator, use a copper F wrench to close relevant valves, and cut off the valves connected to the system 3. Use steam to drive away leaked LPG to avoid Prevent it from spreading to furnaces, air compressors and other places with open flames. If necessary, stop the fire and shut down the work in an emergency. 4. If there is leakage in the tower container, contact the torch in time to relieve the pressure. 5. Arrange personnel to set a warning line at the upwind outlet to prohibit the passage of vehicles and pedestrians. 6. Wait for the relevant leaders to be in place to unified command and arrange the work.

Some time ago, a large amount of leakage occurred in the large cover of the heat exchanger tube and shell side in our device. The unit was shut down for maintenance of the depropanizer bottom reboiler. It may be that the maintenance party did not put the gaskets properly when installing them, which resulted in a large amount of leakage. Dozens of tons of liquefied gas leaked in large quantities. It was very scary. Everyone walked slowly! ! Fortunately there was no explosion. Survived. . I can continue to post in Haichuan and my friends! ! ! :funk:

　　When the gas separation unit was started, the depropanizer heat exchanger flange leaked due to gasket problems. At that time, the temperature and pressure were rising, and a large amount of LPG was sprayed out, causing serious injuries to an operator on site. 　　During maintenance, it must be carried out according to the operating procedures. After maintenance, the pressure test and leak test should be carried out seriously and strictly. Don't be careless. If there is an accident, there will be no regrets.

We prepare the accident plan and upload it for everyone to discuss and analyze together.: A large amount of liquid hydrocarbon leaked from V1202 in the stable tower top reflux tank 1. Phenomenon 1) There was a strong gas smell at the leakage site. 2) There is white mist around the leakage point. 3) Combustible gas and hydrogen sulfide alarms sound. 2 Reasons: A large amount of liquid hydrocarbons leaked due to failure of the extraction flange gasket of the stable tower top reflux tank V1202 body, corrosion and perforation. 3. Treatment principles 1) Motor vehicles are prohibited from driving in and around the installation area and the roads are isolated. 2) Extinguish all open flames in the device and stop on-site construction operations to prevent the generation of static electricity and the occurrence of explosion accidents. 3) Personnel entering the site must wear air respirators to avoid poisoning and frostbite. 4. Treatment method 1) After discovering the leak, report it to the workshop and dispatch immediately, and report the fire alarm according to the procedures. 2) The main burner and continuous light of the heating furnace must be extinguished in an emergency. The reaction, fractionation, air pressure unit and desulfurization units must be shut down in an emergency. Contact the electrical pump stop P1201~1205. 3) Stop the stable feed, cut off the heat source of the stable tower bottom and desorption tower, fully open the pressure control valve PV1205C to discharge non-condensable gas to relieve pressure, close the hot circuit PV1205B of the stable tower top pressure control valve, and fully open the cold circuit PV1205A of the stable tower top pressure control valve. 4) Depending on the stable tower top pressure, gradually close the liquid hydrocarbon cold reflux FV1214, and at the same time close the stable tower top pressure control valve cold circuit PV1205A, fully open the liquid hydrocarbon outlet device regulating valve FV1215, and increase the delivery of liquid hydrocarbons. 5) After the liquefied gas pump is evacuated, close the FV1215 hand valve of the regulating valve of the liquid hydrocarbon outlet device, contact the electrical power outage to stop the pump, and close the hand valve of each regulating valve connected to V1202. 6) Implement steam dispersion and fire water cannon spraying on site. 5 Notes 1) All workers entering the site must wear air respirators. 2) Wear antifreeze gloves and use copper tools during accident handling. 3) Rapid and effective rescue measures must be taken for poisoned persons. 4) Single-person operation is not allowed when entering the leakage area. Two or more people must perform the operation. 5) Operators should pay attention to changes in wind direction and should try to operate upwind.

Thank you upstairs, I learned a lot.