hollerg
Chemical
- Mar 22, 1999
- 97
Vacuum distillation trains that process flammables and combustibles above the flash point, would seem to always have a spot in the process that cannot avoid passing through the flammable envelope, in the condenser or in the vacuum pump or on the outlet of a vacuum pump. It could be caused either from air leaking in, or when a leak develops.
I can conceive that I meet the “static velocity guidelines in a co-current 2-phase drain line normally, but that the velocity goes way up if the 15 lb/hr capacity of the vacuum pump is really required.
My company wants me to break the fire triangle 2 ways. I am trying to understand when and how to take the extra step to prevent static accumulation and ignition, in addition to adding nitrogen to stay outside the flammable range.
A) If my flammables are conductive and in conductive equipment, what does the piping between the exchanger and the receiver need to look like?
B) How do I determine if flow leading to sufficient charge separation to be a static hazard would occur?
C) What guidelines for mitigating this situation do companies use?
D) I have also seen many condenser installations that do nothing to add nitrogen or worry about the velocity when air leaks in, in flammable service. I also have not yet found any loss prevention books that show this spot in the process as an issue that results in losses. Any opinion on why?
I can conceive that I meet the “static velocity guidelines in a co-current 2-phase drain line normally, but that the velocity goes way up if the 15 lb/hr capacity of the vacuum pump is really required.
My company wants me to break the fire triangle 2 ways. I am trying to understand when and how to take the extra step to prevent static accumulation and ignition, in addition to adding nitrogen to stay outside the flammable range.
A) If my flammables are conductive and in conductive equipment, what does the piping between the exchanger and the receiver need to look like?
B) How do I determine if flow leading to sufficient charge separation to be a static hazard would occur?
C) What guidelines for mitigating this situation do companies use?
D) I have also seen many condenser installations that do nothing to add nitrogen or worry about the velocity when air leaks in, in flammable service. I also have not yet found any loss prevention books that show this spot in the process as an issue that results in losses. Any opinion on why?
