Heating and regeneration of liquid-air adsorber and liquid oxygen adsorber are generally carried out according to the service cycle. When it is found that the acetylene content in the liquid oxygen of the main condensing evaporator exceeds the specified value, it can be replaced in advance. According to the design, the service life is generally 7 ~ 10d. The liquid oxygen adsorber lasts for 30 days. If the switching is too frequent, the cold loss will be too big, which will also affect the working condition stability of the air separation unit, and it is easy to misoperate.
The operation procedure of heating regeneration is: precooling another adsorber-parallel connection-switching-drainage-standing-heating. The following is an example of liquid-air adsorber.
Precooling should be 4 in advance according to the switching cycle ~ The 5d is carried out slowly until the unused adsorber temperature reaches-173 ℃. Attention should be paid to the operation, slightly open the outlet valve without using the adsorber, slowly introduce the liquid to precool. Otherwise, the liquid air will be vaporized suddenly, and the volume will increase by about 675 times, which is easy to cause overpressure accidents.
Before using two adsorbers in parallel, it is better to increase the main cold liquid level by 100 ~ 200mm, in case that the pre-cooling is not good and affects the working condition inside the tower. The use time of well connection is about 40 minutes.
Switching should be carried out slowly to avoid affecting the normal production of air separation.
The oxygen surface of the main cold liquid should be observed at any time when discharging the liquid, and the accidents of large discharge of the liquid air caused by the unclosed outlet valve should be strictly prevented.
The oxygen surface of the main cold liquid should be observed at any time when discharging the liquid, and the accidents of large discharge of the liquid air caused by the unclosed outlet valve should be strictly prevented.
Standing is to keep the liquid remaining in the adsorber evaporating and the equipment warming up naturally.
Before heating gas is turned on, dry nitrogen should be used to cool to around-10℃, in order to prevent the adsorber from being heated suddenly, causing thermal stress and damaging the equipment. The heating gas should not be too fast, and the cold blowing should also be done slowly, otherwise the silica gel will be broken. Temperature of heating gas is 70 ~ 90℃, when the outlet temperature reaches 5℃, heating can be stopped. The general regulation ends when the exit reaches 30℃.
