Liquid Nitrogen

[egorleski]

Hello. I was reading some stuff through the fog posts that reccomend Liquid Nitrogen. Ive never used it. ive tried fog and haze and dry ice and all sorts of combinations of the three. So naturaly i started looking up stuff on Liquid Nitrogen. Here are my initial questions and i figured why not have a thread dedicated to this method of fog since there is already fog and haze machine threads.
1) Where can you buy Liquid Nitrogen?
2) Does liquid nitrogen require any kind of licensing?
3) If yes to #2, what places offer training?

Thanks

[soundlight]

Being the safety freak, I would add #4, how safe is it to use in a theater environment. But, if it has already been discussed in other posts, I would guess that the safety of it has been discussed in other posts. I just wouldn't want the pure liquid to get on anyone...the doctor used that to burn a wart off me, and it hurt! Alot! (Well, I guess that you do have to take in to account the fact that he also cut it a little bit, and then applied the liquid nitrogen.

[wolf825]

Liquid Nitrogen is used in creating atmospheric effects as well as other commercial uses--but a lot of safety considerations have to be thought about before using it as it will remove the oxygen and create an asphyxia situation much faster than a CO2 Fogger or dry ice will. It is NOT for the Novice and should only be used by professionals and experienced handlers.

Where you can buy it is not a problem as most air/gas, welding gas suppliers and some medical gas suppliers carry it, however the AMOUNT you want to buy may be of consideration. It is very expensive first off..not really affordable for most folks for playing around with..and you must usually have your own containment for it--which is a very costly for large quantities. This alone makes LN2 effects out of the price range of most folks except large scale professionals. It is sold in dewars in some places, but not in tiny quantities where you can go pick it up off a shelf or something. Its also not something you can buy and leave sitting around for a week or two unless you have proper storage facilities--and those facilities require special construction and materials. Usually its sold in large quantities only and sold only to professionals who know how to handle it and can provide answers to what they plan on doing with it to the gas suppliers.

LN2 is not for the novice--it is very dangerous in handling even moreso than Dry Ice. It is usually sold in LARGE bulk quantities and you must have proper storage containers and facilties for it. This is not something you can pour into a theromos or a cooler and tote around... LN2 is around -375 degrees F, it will freeze and brittle plastics, foams, rubber and some thin steel and anything else it comes in contact with. It cannot be 'contained'--like capped in a bottle for transport or in a small test tube in any form--as it will violently explode moreso then dry ice will if contained. It cannot be handled safely without a lot of precautions--it "boils" when exposed to air and can often splash and spray everything around it, and can be very very dangerous. It will freeze and destroy skin on mass contact and can cause severe burns and blindness. So proper face shields, long sleeves, aprons and gloves are needed when handling it.

No licensing is needed in most places I have been and had it used, but I guess that will vary from state to state--and any laws on obtaining it probably will change when some redneck IDIOT decides they wanna make instant ice cream in their trailer and they accidentally drop it on their kids.. For the average person--LN2 is not a feasable toy or thing to play around with that is cost effective. For example, storage tanks in theme parks for LN2 effects can cost in the tens to hundred of thousands of dollars depending on its size, for its specialized design and materials. A lot of precaution, and a lot of special handling, and a lot of basic human safety considerations IS required for dealing with LN2..

my two cents...
-w

[Chris15]

Wolf's comments are interesting. I am somewhat surprised by its dangers. After all, 70 whatever % of the air we breathe is nitrogen. But I guess that is the same as almost anything else, in moderation it is fine but in quantity you run into problems and also when you have rapid changes. To soundlight, from the original post, I believe that he is saying that since all the other types of haze / fog have threads, why not have one for Liquid Nitrogen. #4 definitely is applicable. From wolf's comments, my advice is this, since you are asking these questions, you probably should not use liquid nitrogen because of the serious dangers that wolf has made clear.

[len]

No arguing with the above comments. It also depends on what you intend to do with it. LN2 can be used to chill fog. But that requires some equipment in addition to a fogger, such as an LSG http://www.lemaitrefx.com/indexx.php Yes, those in the link only require CO2, but you get the idea.

The other thing I can think of to do with LN2 is to shoot it as a chiller onto a crowd. http://www.effectsco.com/index3.htm is one example but again with CO2. However, this is NOT, NOT, NOT, a system you should home-make. It requires O2 sensors and needs to be professionally installed. Improper use/installation could lead to unconsciousness or even death. I'm sure there are other theatrical uses for LN2 but I can't think of any.

[egorleski]

I guess my main thought was using it as a more effective chilling method. But the inability to obtain small quantities make that more of a hassel then its probably worth. On the just wondering tangent... say you did find quantities that would make it feasable to use LN to chill fog, and that you devised some contraption that wouldn't get destroyed by the LN and could have the fog pass through it. Everything ive ever heard says the colder the fog the more low lieing its gonna be. But at some point do the glycols freeze? is there a point where it's too cold?

[mbandgeek]

Originally Posted by soundlight

Being the safety freak, I would add #4, how safe is it to use in a theater environment. But, if it has already been discussed in other posts, I would guess that the safety of it has been discussed in other posts. I just wouldn't want the pure liquid to get on anyone...the doctor used that to burn a wart off me, and it hurt! Alot! (Well, I guess that you do have to take in to account the fact that he also cut it a little bit, and then applied the liquid nitrogen.

why Do you need liquid nitrogen?

[wolf825]

Here is a link of Safety and FAQ for LN2 and some LN2 effects. Of course you could just GOOGLE search and you would find all the Safety precautions taken by Universities around the world on its handling as well.

http://www.interesting-products.com/faq.html

Be safe folks...
-w

[len]

Originally Posted by egorleski

Everything ive ever heard says the colder the fog the more low lieing its gonna be. But at some point do the glycols freeze? is there a point where it's too cold?

Not really, because the actual fog/smoke is chilled, not the liquid. An LSG is basically an air conditioner. The fog machine outputs, then the fog is cooled without changing the visibility much. Since hot gases rise and cold gases tend to fall, the chilled fog hugs the ground.

If this is something you're looking to do, but are looking for a lower cost alternative, here's 2:

First, LeMaitre makes a product called the LSX. It's basically a room air conditioner designed to process and chill fog (it even has a built in stand for a F-100 or similar sized fogger) without any gas.

The other option I've heard of is to buy a large picnic cooler. Cut a hole in one end which would match up to where the fog nozzle would be. Cut a hole at the opposite end and mount a bisquit fan http://www.sciplus.com/singleItem.cf...egory%20Filter to blow the fog out. Fill the cooler full of ice (dry ice works better) and seal with duct tape. Be careful handling the dry ice.

There are also true dry ice foggers, but they're big and expensive for the amount of use you're likely to give them.

[soundlight]

Kinda going on a tangent, but Hurrah for SciPlus! American Science and Surplus! They have a huge variety of awesome stuff.

But back to the topic, I'm guessing that you can say that LN2 should not be used unless you have been given proper instruction, have proper equipment, and have the money...and it should not be attempted by anyone without the means or ways.