3 replies to this topic

[kangas]

Hello I am designing a distillation column containing some flammable chemicals (e.g. acetic acid). I am considering to have it as vacuum. Is there a high risk of explosion due to air inward leakage? Can I estimate the amount leaked in for 50mbar?

 

 

[breizh]

Hi,

Consider the fire triangle , description attached , to support your work :

https://www.sc.edu/e...be extinguished.

 

You should perform a safety review with your colleagues at the work place.

https://inchem.org/d...sc/eics0363.htm

 

 

Breizh

[bcchiu]

kangas, thanks for bringing the question out.

I have the same question about the internal fire risk of vacuum distillation which handles flammable liquids, since some engineers in PHA think that even if there is air inside the column before startup, the vacuum control system providing vacuum environment e.g. 100 Torr can take away the air from the column, so they think that the risk of fire & explosion in the column is low. However, as a safety engineer I think it has some possibility letting flammable vapors to reach flammable range during the operation of startup. Therefore, I suggest that purging with nitrogen in process units prior startup is required. I am wondering if there are any RAGAGEPs or Codes and Standards that should be followed. I would appreciate any comments or suggestions.

 

Regards,

 

Bcchiu

[seuenergy]

Hi, Bcchiu

 

Agree with your point.

The risk of fire/explosion still exist even when pressure of mixture below ATM(called vacuum).

But as the partial pressure of oxygen is lower when vacuum formed, the possibility of fire actually drops. because the concentration of oxygen easily drop below LOC(limit oxygen concentration).

 

kangas, thanks for bringing the question out.

I have the same question about the internal fire risk of vacuum distillation which handles flammable liquids, since some engineers in PHA think that even if there is air inside the column before startup, the vacuum control system providing vacuum environment e.g. 100 Torr can take away the air from the column, so they think that the risk of fire & explosion in the column is low. However, as a safety engineer I think it has some possibility letting flammable vapors to reach flammable range during the operation of startup. Therefore, I suggest that purging with nitrogen in process units prior startup is required. I am wondering if there are any RAGAGEPs or Codes and Standards that should be followed. I would appreciate any comments or suggestions.

 

Regards,

 

Bcchiu