What are the experiences and suggestions of gas holder maintenance?

Although oil refining enterprises generally adopt the measures of recovering gas from wet gas holders, and some enterprises are studying and preparing to replace dry gas holders, due to the particularity of dry gas holders, the maintenance and operation management of gas holders is difficult.
(1) When replacing the steam in the gas tank, the time should not be too long. It is better to stop the steam for 30 minutes after seeing the steam from the vent pipe. When replacing with steam, we only consider that the cleaner the air is, the better the replacement time is, and the replacement time is up to four hours, which causes the temperature in the tank to be too high. The seal oil temperature is up to 84 C, and the oil level in the piston oil tank drops sharply, making the oil supply pump run continuously for a long time, which affects the quality and effect of the seal oil. At the same time, because the seal oil temperature is high, the dry degree is small, the volatile, and the drop between the piston oil tank and the top of the tank is large, the seal oil splashes a lot when it circulates and falls, Cause unnecessary waste. If possible, it is better to use nitrogen directly for replacement.
(2) After the gas holder is put into use, the prominent problem is that the flash point of the sealing oil drops, endangering the operation and production safety. Although the condensate drainage facilities and sealing oil treatment facilities have been added successively, the effect is not ideal. It is recommended to consider the exhaust and blast facilities on the top of the gas holder and conduct forced ventilation to increase the release rate of condensate oil and gas in the sealing oil