Liquid Nitrogen Help
Friends, I need some advice/help. I have stepped into a new role and I an item that I have not encountered before. I have question and what better place to ask than here!
The photo is a barrel that I place parts in and fill with liquid nitrogen from the bottom up through gravity feed past a seal and then is shut off. It shrinks the seal and lets the Nitrogen Gas out. This is then just let out of the top of the barrel into the surrounding atmosphere. I know there is a better way to handle this. It is an isolated area with a procedure to not approach till the off gassing as ceased. The parts are then removed with specialized gloves and placed into a warmer to be handled with the bare hand. What are major risks and concerns here?
Comments (19)
I feel like the big safety concerns with liquid nitrogen are burns, and malfunctions that could result in off-gasing to the point of oxygen deprivation. How much does the system off-gas?
Haz Mat not my forte, but I know enough to be "dangerous", :) so do not take my words as gospel. But my first impression is this is concerning but not what I would call "imminent danger." If was in an enclosed area I would be more concerned. The hazy gas is probably a mix of steam from the humidity and the air and Nitrogen. I would not think overly concerning as the N might be hazardous if it displaced enough O2, which would take one heck of a lot of N to do that in such an open area. I would be concerned if someone breathed in the gas as it is probably super cold, but it appears the gas is below waist level on an average human. I think I would still have someone wear some sort of respirator when close to the barrel, possibly with a NO2 Cartridges. I do not see N listed in the "bible" (NIOSH Pocket Guide, but do see NO2). NO2 might be formed by the N coming in contact with the O in the air, but N is relatively inert, if I recall my hs Chemistry, at least until you take other precautions like venting the gas outside or at least increased ventilation to disperse if quicker. Except we are talking serious "bread" now, and the "new guy" is not often heard on $ stuff. well (I guess you would learn about your Management quick).
My other concern is the cold. You have them wearing gloves, but if you remember your Safety 101, and the Hierarchy of Controls, PPE is supposed to be an interim step.
How often do your people do this? As a MFG guy I would think if this is a much used process you would have it automated like a dip conveyor or washer of some sort. Robots would be over the top and BIG Bucks! My $.02.
I am sure there are better answers from others! Very good you are concerned, that is the first step!
Is that a dewar? Or just a drum?
How much total liquid nitrogen are you using and how do you fill it?
John, this OSHA Fact sheet may be helpful to you! https://www.osha.gov/sites/default/files/publications/OSHAquickfacts-lab-safety-cryogens-dryice.pdf
It's a cryogenic fluid. We used to do this (shrink fitting) at my last workplace. We would also place it into a Styrofoam cooler to prevent it from leaking out (shown in the picture). You'll need cryogenic PPE rated for the actual temperature of liquid nitrogen because not all cryogenics are the same temperature.
The liquid nitrogen has to be used within a certain time frame, so make sure that's taken into consideration so that people feel that they have to rush. Your major injuries are frostbite, as well as asphyxiation if you're doing it in an enclosed/confined area, so just make sure you have adequate ventilation.
