I'm looking into using LN2 for a specific "vanish" effect which I don't believe can be achieved with more conventional means (i.e. dry ice, co2, etc). Does anybody here have any experience working with it? Having spent the last few hours on Google, i've been unable to find any dry fogger machines that work with the stuff. Considering the desired blast of fog only occurs once during the performance and should only last a few seconds, how feasible would it be to make my own dry fogger? I was thinking something along the lines of an old cooler box with a hole cut out for ducting. Hot water sits at the bottom. When it's time for the fog blast, the required amount of LN2 is places in a bucket above the hot water and the box's lid is shut. Via some mechanism, the bucket of LN2 is tipped into the water and "hey presto!". A crude method perhaps, but would work similarly to a traditional dry ice "pea soupper".
With regards to safety, I've performed the necessary Oxygen depletion calculations for our stage size (not even taking into account the size of the auditorium) and we could safely store 25ltr of LN2 in a dewar tank offstage without the O2 levels falling below 20% in a worst case scenario (i.e. the whole lots spills out of the tank). Procedures will also be in place for the correct and safe handling of the liquid.
With regards to safety, I've performed the necessary Oxygen depletion calculations for our stage size (not even taking into account the size of the auditorium) and we could safely store 25ltr of LN2 in a dewar tank offstage without the O2 levels falling below 20% in a worst case scenario (i.e. the whole lots spills out of the tank). Procedures will also be in place for the correct and safe handling of the liquid.