# cryogenics and co2?



## JahJahwarrior (Mar 21, 2006)

Hey...I was thinking recently that using co2 to produce jets of smoke would be pretty simple, and reasonably safe. As long as you are a few feet from thenozzle, there should be no problems with freezing (I have a little bit of experience with liquid co2, from playing paintball. Once upon a time, I managed to get a valve stuck, venting co2 right onto my wrist. 3rd degree burn, biggest blister I've ever seen, and becuase it was on my wrist, for months afterwards the burnt area would bleed just a bit--everytime I'd flex my wrist, it'd crack the scab a bit. but if you are even a foot away, it shouldn't harm you, I'd think), and bulk tanks of co2 aren't that much to rent. Does anyone know much on them? I cannot find tons on google....has anyone used them? am I wrong about how safe they are? Can I build a system myself/has anyone here done it, or can I buy one cheaply? 

Thanks!


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## Mayhem (Mar 22, 2006)

Motley Crue had CO2 ‘smoke’ for their last tour and although I didn’t get a good look at the system, it seemed fairly simple in design. There were several “nozzles” across the front that were about 2” in diameter and 4” long. I’m guessing that the feed pipe was about 1/2. 

During the gig I was side of stage and the CO2 jets were loud but also very effective. However, long duration blasts did result in hail falling down on the stage!

Unfortunately I never got to see how the system was controlled but I imagine that all the valves and couplers would have to be fairly large to reduce the risk of icing up.

All in all, a cool look but very noisy and definitely something that you do not want to be too close too.


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## len (Mar 22, 2006)

http://www.effectsco.com/index3.htm is one place that makes CO2 jets, etc. They have a couple moving heads which are dmx controllable. The key to the system is the oxygen sensor. Even though CO2 won't do much damage to skin if the jets are far away, they can force all the oxygen out of a room, which is a bad thing. I've never worked with them, but they are cool looking in the video.


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## Mayhem (Mar 22, 2006)

len said:


> Even though CO2 won't do much damage to skin if the jets are far away, they can force all the oxygen out of a room, which is a bad thing.



Excellent point and one that is of upmost importance. This is one reason that CO2 is very good in fire extinguishers. 

Wonder if those little DMX units could find a function as a remote fire control unit. How cool would you look if you were to put out a stage fire from the comfort of the booth!


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## koncept (Mar 22, 2006)

Mayhem said:


> Wonder if those little DMX units could find a function as a remote fire control unit. How cool would you look if you were to put out a stage fire from the comfort of the booth!



that would be amazing, but would probaly require large ammounts of co2 depending upon stage size and size of the fire. all in all i think it would be a very cool effect for theatre if you did not need to worry about actors being injured by it.


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## JahJahwarrior (Mar 22, 2006)

Eh, should be easy enough to calculate and have a wide safety margin to keep enough oxygen in the room. Plus, a few doors culd be opened and fans put in place before hand to circulate. I've got a chem teacher who might could help me figure out how to make sure we keep o2 in the room


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## Radman (Mar 22, 2006)

Hehe or the actors could wear SCBAs (SCUBA minus the underwater) hehe I bet the costumer would love figuring out how to hide that under the costume...


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## koncept (Mar 22, 2006)

if you do get to use these, please take pictures and post comments. i would be very interested in thier performance. I think it is safe so long as actors are not directly breathing the streams in.


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## len (Mar 23, 2006)

The only place I've seen them used is in nightclubs, but that's probably because I don't go to the theatre as much as I'm in nightclubs. There is also a nitrogen system that chills the air. It's pretty intense.


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## MHSTech (Mar 23, 2006)

Mayhem said:


> Wonder if those little DMX units could find a function as a remote fire control unit.


If you can get DMX to control a servo motor...we're in business. 

Just as long as the working area doesn't reach over 426 PPM of Co2, you're good. I may be wrong, but I believe 426 PPM is the most Co2 you can take without getting poisoned.


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## kingfisher1 (Mar 23, 2006)

MHSTech said:


> Just as long as the working area doesn't reach over 426 PPM of Co2, you're good. I may be wrong, but I believe 426 PPM is the most Co2 you can take without getting poisoned.



Might want to leave a little margin of error. thtas kinda like saying "hey, this rope hold 90lbs! i weigh ninety pounds! lets dangel over a cliff with it"


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## Radman (Mar 23, 2006)

What kind of person weighs 90 pounds? (Not to throw a fork in you logic or anything...) 

I think it sounds cool. I've experienced a bit of CO2 from paintball and FX stuff as well.


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## Mayhem (Mar 24, 2006)

Radman said:


> What kind of person weighs 90 pounds? (Not to throw a fork in you logic or anything...)
> 
> I think it sounds cool. I've experienced a bit of CO2 from paintball and FX stuff as well.



The kid in the “Skinny white boy” banner ad for T-shirt hell!


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## jwl868 (Mar 24, 2006)

On the subject of how much CO2 becomes hazardous:

While there is the possibility that the CO2 could displace all of the oxygen in a room or at floor level, the ventilation in most auditoriums etc should prevent this. Low spots where the heavy gas could collect with limited air movement (such as an orchestra pit or a small basement storage room below a stage) could be a greater problem, but even then it’s a matter of additional caution. Industrial situations where deaths from lack of oxygen (or poisonous gas) tend to be in confined, limited access, and limited ventilation locations, such as sub basements, tanks, and sometimes deep excavations.

Regardless, the consideration is not necessarily the amount of carbon dioxide that will displace all of the air, but rather the quantity of CO2 that will mix with the air and displace just enough oxygen such that the oxygen concentration is reduced from the normal 21 % down to 19.5 %, this being the definition of "oxygen deficient". [Please note that these are volume percentages not weight percentages; by convention gas percentages and concentrations are always on a volume basis unless otherwise noted.] It is at this percentage where one begins to suffer from lack of oxygen. Zero % oxygen is fatal – but so is 15% oxygen. (The best analogy someone gave me was that in the lungs, oxygen transfers across membranes from the air to the blood because, and at 21 %, the oxygen partial pressure is greater then the oxygen pressure in the blood. But when the oxygen percentage in the air drops below 19.5%, the oxygen pressure is lower than that in the blood and the transfer does not take place.)

So if you do this calculation, the amount of CO2 is not the volume of the room, but rather, a small percentage of it. Also, it is not a 1 to 1 displacement of oxygen by the CO2, because air is about 78 % nitrogen. So to move out the equivalent of 1.5 % oxygen (the difference between 21 % and 19.5 %), the CO2 must also move out 4.5 % of the nitrogen. So its about 6 % of the volume of the room. And all this assumes that the CO2 is completely mixed with the air.

But, and see below, according to NIOSH (National Institute for Occupational Safety and Health), CO2 has lethal effects at a somewhat lower concentration than that – namely 4 %: 

NIOSH REL: 
5,000 ppm TWA 
30,000 ppm STEL 
40,000 ppm IDLH 

Current OSHA PEL: 
5,000 ppm TWA 

REL - NIOSH recommended exposure limit.
TWA - indicates a time-weighted average concentration for up to a 10-hour workday during a 40-hour workweek.
STEL - short-term exposure limit; unless noted otherwise, the STEL is a 15-minute TWA exposure that should not be exceeded at any time during a workday. 
IDLH - Immediately Dangerous to Life and Health.
PEL - OSHA permissible exposure limit (This is enforceable).
ppm – parts per million (by volume).

The IDLH of 40,000 ppm = 40,000/1,000,000 x 100 = 4%.



I had some other posts on the subject see:

ControlBooth > Special F/X > F/X Questions? 
Hazers vs. Dry Ice--Health Risk 

Joe


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## MHSTech (Mar 24, 2006)

Current OSHA PEL:
5,000 ppm TWA 

That's the little tidbit of info I couldn't find. Thanks for the correction.


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## JahJahwarrior (Mar 26, 2006)

so....does anyone have any clue how to do this without buying aimable jets and stuff? I don't need anything DMX controlled.....20 feet of hosing that would direct the stuff (I know they make stainless steel braided covered hosing for paintball guns, but i have never seen it in 20 foot lengths) and a nozzle of some sort, and a valve thats easy to open and shut? How long will a bulk tank of the stuff last? Could I get a cool "puff" affect by venting quickly just say a 20 oz tank? I have access to a few of those.


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## koncept (Mar 26, 2006)

call a welding supply shop. they should be able to help you out


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## MHSTech (Mar 26, 2006)

JahJahwarrior said:


> How long will a bulk tank of the stuff last?


Depends what size of tank you get.

Also, you should be able to get your C02 from whoever refills/recharges your fire extinguishers. And as for the 20 ft of whatever, you should be able to get away with using steel pipe...say 1/8" or 1/4"? 

If you just want to create a puff of C02, I don't know if you really need a nozzle. Maybe somebody else could answer this.


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## JahJahwarrior (Mar 27, 2006)

well, not just a puff like a tiny cloud, but say I want to have co2 shoot 10 feet high for 10 seconds. I'm guessing I need to know how far to crack open the valve? And using pipe would be cumbersome, but doable. I wish someone on here had extensive expereience with this....I have not had much luck on google.........


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## Mayhem (Mar 27, 2006)

Well without the extensive experience you are Googling for, ask yourself this question? How does a CO2 fire extinguisher work?

Essentially, you are trying to reproduce a similar unit, although you wish to have a higher stream and that I suspect is going to be determined by pressure and nozzle size and shape. 

The long nozzle on the extinguisher is there to focus and concentrate the CO2 and your nozzle would be smaller than this. As I previously mentioned, the ones used by Motley Crue were only about 3 or 4 inches high and probably no more than 2 inches in diameter.

The pipe is going to need to be at least a half inch in diameter I think and for R&D purposes, I would use a ballcock valve to gauge the flow rate required. Whilst I have never pulled an extinguisher apart, my guess is that it would open the valve fully.

Pressure in the canister is also going to play a role in getting the desired effect and off the top of my head, I cannot recall what a CO2 extinguisher is set at. To be honest, I cannot even recall if it shows pressure or just a charge/good indicator. 

One problem you will probably encounter will be icing due to components getting too cold and this may be due to too small diameters or too high a flow rate or a combination of the two.

I guess that you are going to do some experimentation with what you have lying around and what you can pull together. 

My advice is this: 

1. Speak to a local company that services fire extinguishers and ask them for their thoughts and comments on such a system. They should be able to help you with flow rates, diameters and the likes. 

2. Whatever you try out, make sure that you are protected and at the very least wearing safety glasses and a long sleeved top and jeans. This stuff can give a nasty burn and you sure as hell don’t want to get it in your eyes. 

3. The pressure could cause the nozzle and hose to fly about so make sure it is securely fastened.

4. Test is in a well ventilated area and have someone with you in case you do get injured.

5. Do not say “oh what the hell” and use a CO2 fire extinguisher as the FX. Fire extinguishers should be used for one thing only - Fighting fires. Now I know that several people will disagree with me and tell me they do it all the time. My reasoning is that should a fire break out and the extinguishers emptied to get a cool FX, I am not going to be a happy camper.


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## Chris15 (Mar 28, 2006)

Mayhem said:


> Well without the extensive experience you are Googling for, ask yourself this question? How does a CO2 fire extinguisher work?
> 
> Essentially, you are trying to reproduce a similar unit, although you wish to have a higher stream and that I suspect is going to be determined by pressure and nozzle size and shape.
> 
> ...



I believe that a CO2 extinguisher is operating at a pressure in the vicinity of 6MPa. I can see only one possible reason why a fire extinguisher could be used for FX and that is when it has been brought in specially and is not needed as part of the building's fire plan, but it would normally be easier just to say don't do it.


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## jwl868 (Mar 28, 2006)

Note that cryogenic (liquefied) CO2 and compressed CO2 are two different products. Same chemical, just different states, like ice and water. 

Cryogenic means cold temperatures and with gases, that means the gas is liquefied. (At the cooler temperature, the vapor pressure is also reduced.) If an industry wants a very large volume of product in a small container, then that is what industry uses. (Liquefied CO2 expands about 900 times in volume to gas form.) I couldn’t find the CO2 vapor pressure under the typical industrial cryogenic system (but I didn’t do a thorough search), but I am under the impression that it is a 200 to 300 psig (pounds per square inch gauge).

CO2 can also be compressed like any other gas and all you need is a strong enough container to handle the pressure. Fire extinguishers use compressed CO2. They are at room temperature and are not insulated, and the internal pressure is very high. The vapor pressure of CO2 is over 800 psig, and fire extinguishers are at about 1,500 psig.

Be aware that compressed and liquefied carbon dioxide are common commodity gases. When handling compressed gas, valves, piping materials, and fittings are very specific and are made for the particular gas. (For example, the threads for a pressure regulator that one might use on a hydrogen tank will not fit on a compressed air tank.) Pure gases at high pressures and/or low temperatures can have unexpected effects on materials. Likewise, the air line valve that one could get a hardware store for a home air compressor is probably rated for a couple hundred psi, but the vapor pressure of CO2 at 70 F is over 800 psig. 

The Compressed Gas Association has numerous documents regarding the safe handling of compressed gases, and probably liquefied gases, too. You can probably find more information about liquefied and compressed gases at the major suppliers, such as Air Liquide, BOC gases, and Air Products and Chemicals.

Compressed gases can be unforgiving. I think you need a professional to assist you in this.

Joe


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## Mayhem (Mar 28, 2006)

Chris – my problem with using a specific extinguisher for FX only is that someone running to put out a fire will not stop to think “oh, that was used for FX and is empty”. They will grab it and might place themselves in danger because it is empty.

Joe – good information and advice. Have seen liquid CO2 used in conjunction with LSGs before, using standard pressure hoses, so I guess the regulator setting is the determining factor here. My understanding was the compressed CO2 (such as that used in paintball guns) was going to be used here and agree with you that professional advice should be sought if using liquid CO2 or compressed CO2 at large pressure ratings.


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## Chris15 (Mar 29, 2006)

Mayhem said:


> Chris – my problem with using a specific extinguisher for FX only is that someone running to put out a fire will not stop to think “oh, that was used for FX and is empty”. They will grab it and might place themselves in danger because it is empty.
> 
> Joe – good information and advice. Have seen liquid CO2 used in conjunction with LSGs before, using standard pressure hoses, so I guess the regulator setting is the determining factor here. My understanding was the compressed CO2 (such as that used in paintball guns) was going to be used here and agree with you that professional advice should be sought if using liquid CO2 or compressed CO2 at large pressure ratings.



Yeah, valid point. Forgot to figure in the panic factor.


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## JahJahwarrior (Mar 29, 2006)

I was under the impression that co2, when compressed, changes states to become a liquid. ie: liquid co2 is made by pressurizing gasseous co2. Co2 tanks on paintball guns exert, I believe, easily 1800 psi? And bulk tanks for filling co2 tanks for paintball use a siphon tube dipping into the liquid co2 so that they will fill the co2 tank with the liquid, which will expand into a gas on it's way into the valve (some guns actually run on the liquid, but most will freeze up). 

I think I'll have to just call a company that does this sort of stuff and ask if there is cheap, non dmx sort of way to do this safely...


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## Mayhem (Mar 30, 2006)

JahJahwarrior said:


> I was under the impression that co2, when compressed, changes states to become a liquid. ie: liquid co2 is made by pressurizing gasseous co2. Co2 tanks on paintball guns exert, I believe, easily 1800 psi? And bulk tanks for filling co2 tanks for paintball use a siphon tube dipping into the liquid co2 so that they will fill the co2 tank with the liquid, which will expand into a gas on it's way into the valve (some guns actually run on the liquid, but most will freeze up).
> 
> I think I'll have to just call a company that does this sort of stuff and ask if there is cheap, non dmx sort of way to do this safely...



Well I think that we would all agree that you are correct in saying that this is something that needs further investigation. 

As far as using some sort of control mechanism other than DMX, you could use a solenoid to fire them. That is how we do our LPG flame projectors. Not the cheapest things to buy and you would have to get one(s) approved for use with CO2. The control system is easy and inexpensive to build after that.


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## JahJahwarrior (Mar 30, 2006)

Ah, I wanted touse the effect with this time machine I'm building for our schools next production (the actors travel back in time and meet famous Christian missionaries, like Hudson Taylor), if I managed to figure it out, I wouldn't bother with solenoids, I'd just get someone to throw a valve. I have one month.... but I probably won't have time.....the crappy thing is, our fog machine is caput, and I don't think we have the budget to buy a new one. And our budget, if we had one, would be stretched to even get a nice Chauvet fog machine.........


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## Radman (Mar 30, 2006)

Maybe look into rental?


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## saxman0317 (Mar 30, 2006)

Well....i too play paintball, and the bulk tanks should be easy to get. Just go to the local welding supply. To make your rig, just use simple braided still cable with butterfly valves and such with regs to make it down to desired pressure(that will require tweaking for desired effect). As far as working, thats up to local code and the venues personal feelings. Being in the fire service though, that fire extigusher thing wont work here. Theres a reason extengushers only work in a small area, they do decrese the O2 levals in that area, but only slightly...its more a cooling effect that the CO2 has on the fire..physics thing. That little amount in a large venue wont do anything what soever, less than shooting a hopper of paint inside. Other than that, it should be an easy thing to to do, but i find that dry ice when put in a shopvav works well for that stuff...


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## Mayhem (Mar 31, 2006)

saxman0317 said:


> Being in the fire service though, that fire extigusher thing wont work here. Theres a reason extengushers only work in a small area, they do decrese the O2 levals in that area, but only slightly...its more a cooling effect that the CO2 has on the fire..physics thing.



Sorry but I disagree with you. The role of CO2 in fire fighting is to starve the fire of oxygen (same as using dry chemical, foam, dirt or a blanket). 

Fire fighting has a couple of simple principles. Remove the fuel, cool the fuel to below its flash point or remove the oxygen supply. 

Water is used to cool a fire to the point of extinguishing it but you generally need a hell of a lot of it to do this. Fortunately, water is relatively inexpensive and readily available in a pressurised form straight out of the wall! Water is also useful for cooling material that is close to the fire but has not yet caught alight. This is a very good way of preventing fires from spreading and you could put out a fire this way. That is, you stop the fire from spreading and allow it to burn up the fuel that is already alight. Once it has burned up all its fuel it will go out.

Remember that things do not simply burst into flames. They need to be heated first and during this heating process the material will give off vapours. It is these vapours that catch alight. Next time you place a log onto the fire, watch it. 

Extinguishers work in a small area to concentrate their efforts and this is the reason for the nozzle on a CO2 extinguisher. You want to be able to direct the extinguishing material to where you want it. There are larger systems that will fill a room (such as on ships) for CO2 drenching of a confined space.

The overall level of oxygen depletion is only important at the site of combustion. Deprive the fire and it will go out. CO2 does this very effectively. The cooling effect is a bonus but not the primary means.

CO2 is heavier than air, so “sinks” and displaces the oxygen. This is the same principle used in MIG welding. The Agon gas used displaces the oxygen so that the weld is clean and will not oxidate. 

Dry chemical extinguishers use baking soda (or an almost identical compound) which actually does two things. Firstly, it will smother the fire but it also heats up and when it does, it gives off CO2. This is why every house should have a box of baking soda in it!


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## MHSTech (Mar 31, 2006)

Mayhem said:


> Fire fighting has a couple of simple principles. Remove the fuel, cool the fuel to below its flash point or remove the oxygen supply.


Bingo! And yes, it is the gases given off when you heat a substance that catches on fire, not the actualy substance. One way to demonstrate this...take a candle and burn it for a while. Light another match, blow out the candle and hold the match in the white colored smoke over the wick. The flame will catch the leftover gass on fire and the candle will reignite. Yeah, I'm also involved in the fire service.


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## JahJahwarrior (Apr 1, 2006)

you know, it never occured to me that to regulate it, I could just use a paintball reg. Should still let plenty of junk through and I could get a cheap one, say off of an old WGP autococker. (for paintball people, I shoot an automag with hpa, so I don't have an external reg I could just borrow for it  ) 


I might still look into it, but first priority is building a time machine. The co2 thing sounds a bit harder to achieve than I had figured.....I could always do some trial and error, but I don't have the time right now. but yes,a bulk tank would probably only cost me $20-40. I think I could rent one for a while for about that much, or less.


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## Radman (Apr 1, 2006)

JahJahwarrior said:


> I might still look into it, but first priority is building a time machine.



Just another reason why this business is so great.  


I think a paintball regulator sounds like a good idea, I'd those things would be pretty accurate, to ensure consistent shots and such.


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## Living Illusions (Apr 1, 2006)

Look Fog machines from Germany make a fogger that can shoot straight up. Using quick disipating fluid allows a plume of up to 25' to shoot out and disapates in three seconds. That's just a hair longer than CO2.

We use two of them downstage, have Source Four Pars just upstage of the fogger and aim it upwards. Through our lighting software, the fogger and lights kick on for 4-5 seconds, with the source four staying on a second longer.

We have colored it with blue gels..and have also kept it a brilliant white. With the audience having a closed retina, it almost has a flash or pyro look to it.

CO2 can be finicky depending on humidity. The fogger works every time.

Hope that helps.
Kevin


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## koncept (Apr 2, 2006)

I like the idea of a fogger, there are several that have a compressed air input that might allow you to shot it up like that if the fogger cannot do it on its own. Only thing with using compressed air is you would need a control for it unless you were to just shoot it manualy


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## MHSTech (Apr 2, 2006)

Yeah, you could use compressed air to induce quick disipating fog through a wye.


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## Mayhem (Apr 3, 2006)

JahJahwarrior said:


> .....first priority is building a time machine.



Whilst it is not going to help – I couldn’t resist sharing this with you. This was sent to me a few months back from a friend. Apparently it was for sale on a New Zealand web site (similar to eBay). Whilst the time machine is nothing special, the questions that were posted about it make some pretty interesting reading.

The .pdf was over the size limit, so I have posted it on my site. Click HERE to view it.


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## jwl868 (Apr 4, 2006)

I tracked down a pressure-temperature phase diagram for carbon dioxide, and when compressed to pressures found in fire extinguishers and at the room temperature, carbon dioxide is in a liquid form. (Search for pressure temperature phase diagrams.) But because the temperature is elevated, it is not cryogenic. 

Interestingly, at this temperature and pressure, carbon dioxide will be very close to its “critical” point and in a physical form (“super critical”) where it is in neither a true gas phase or liquid phase (The critical temperature is 304 K, or about 88 F). A change in pressure (with constant temperature) will not bring about a change to gas or liquid when in super critical form. While its more of an academic issue, its behavior is somewhat unpredictable. The cold cryogenic system, however, is well below this critical point, and the gas will condense to vapor (and vice versa) predictably. 

Regardless, the pressure is very high. While the regulator from a paintball gun might be usable in theory, one must consider how that unit connects to a paintball gun, and then, how it would be connected to another device/system. It is entirely possible that there are standard sizes and fitting shapes for a paintball gun regulator that would make it difficult and dangerous to use elsewhere. A paintball gun regulator may also limit the amount of gas that actually passes through it so that it only allows just enough volume to push the projectile. (The analogy would be a garden hose and a fire hose.)

Use equipment for what it is meant to be used for. A compressed gas supply house or laboratory supply house will offer the right equipment.

However, I still maintain that this type of project requires professional advice. The pressure of this gas is far beyond that typically found in common systems, such as water supply and compressed air in industrial use. The jet product that someone linked to in this post is clearly a designed product, and no doubt includes safety features (like pressure relief, bleed, and vent lines) that must be considered.


Joe


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## egorleski (Apr 27, 2006)

We are doing The Scarlet Pimpernel and for Into The Fire i made a simple way of getting jets of fog that is easily customizable and cheap. Run your fog machine into a PVC "straight" T joint(__|__) if your doing 2 jets or if not then just into PVC tubing. At either the single end or at both ends use "slanted" T joints(__/__). (I found this was more effective then a simple bend because it allows for a little fog to be saved and this will be drawn up when the air is put through.) >__/__ make sure the joints are oriented so that the path of the fog will naturaly want to go up. All the PVC up to this point should be large diameter to allow a large resivior of fog to draw from. Out of this joint adapt the pvc down to a smaller diameter. Here is where the custimation begins, the smaller the diamter the tighter, more defined, "jet" you will have. Now take that handy dandy air compressor and connect it to air hose and then put a fitting on it so that you can screw it into somthing. Drill the appropriate size hole for your fitting in the slanted T joint right beneath where it goes vertical. You can adjust the amount of pressure put through the system to adjust the height of the effect. This is open and so pressure shouldn't build up and be a problem, but safe is better than sorry so i recommend using the stronger PVC at least for the section that will have the air going through it.


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## MHSTech (Apr 27, 2006)

This is kind of off topic, but what would happen if you were to compress fog from a fog machine in an air copressor? Would the fog condense inside the tank?


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## Chris15 (Apr 27, 2006)

MHSTech said:


> This is kind of off topic, but what would happen if you were to compress fog from a fog machine in an air copressor? Would the fog condense inside the tank?



I'm not sure how you would get the fog into the compressor. Besides, compressors tend to be noisy and for that reason I would not want one on my stage. I guess that if you were to compress the fog enough, it would become liquid. I would not want to be the one cleaning the compressor afterwards though.


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## MHSTech (Apr 27, 2006)

Yeah, but you could either compress the fog before the show or put the compressor outside of your venue and run an air line. You bring up a good point though, that would make the tank rather sticky, probably start to gum up the compressor, and make the air lines sticky.


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## koncept (Apr 27, 2006)

i have used some quiet compressors that work great. but i would not want to clean that tank....but the foggers with a air input are designed to create something to the effect of what you are making out of the pvc....i like the pvc idea better since a) i dont have the air input adapter thingy and b) i only have on fogger and its been needed in several spots at the same time


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## len (Apr 28, 2006)

JahJahwarrior said:


> well, not just a puff like a tiny cloud, but say I want to have co2 shoot 10 feet high for 10 seconds. I'm guessing I need to know how far to crack open the valve? And using pipe would be cumbersome, but doable. I wish someone on here had extensive expereience with this....I have not had much luck on google.........



There's a fogger that shoots straight up. No idea who makes it but it's like American dj or something. Would that work?


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## JahJahwarrior (Apr 29, 2006)

I cna make a fog machine shoot in almost any direction I wish if I use a long section of vacuum hosing I have. Infact, I have been using tubing recently to direct and cool the fog. The longer the hose, the more the fog stays on the ground. It does condense seomwhat on the inside of the hose, but not enough to noticiably reduce the fog output at all, and I'm using like 15 feet of hose


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## Cryogenifex (Feb 27, 2011)

The Co2 effect is reliable and repeatable. These Co2 Jet system can be used with the high pressure Liquid CO2 tanks or refrigerated liquid dewar tanks to add to its versatility. Hit me up if you need anymore info.


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## Dalamar (Mar 12, 2011)

Unfortunately, I'm in a hurry so I cannot go deeply into this subject but, if you will allow me this brief comment. 

a) L-CO2 (Liquefied or Liquid, refrigerated Carbon Dioxide) is commonly distributed commercially from ~125 PSI to 350PSI, and a stable average of ~225 PSI. Anything below 125 would likely freeze CO2 valves (which are undoubtedly used in most cryogenic system) and most containers are calibrated to release (vent) pressure for anything above 350. 

b) most commercial CO2 containers are at 890 PSI, at 20 degree C.

c) I am NOT AN EXPERT at using cryogenics per se, but I've dabbled with it by professional osmosis. As such, allow me to suggest you made sure to use a pressure regulator, as I am fairly certain that the effect you want can be achieved at a much lesser pressure than the nominal 890 PSI. *Consult an expert.* 

d) Pushing fog though a compressor is hardly ever a good idea because the "fog" is more than likely at room temperature when it goes through the compressor, and therefore is in liquid state. It will condense (read leave residue / leak) in a confined area (said compressor), and, eventually, damage it. the same will occur in vacuum cleaner conduits, as they are seldom lager than 2" in diameter. To get fog flowing a minimum of air must be forced through a conduit to maintain velocity, avoid condensation and ensure the fog will exit where it is desired. 

e) fog effects "shooting" up are cool, but it's quite touchy to achieve something that will dissipate almost instantly like you seem to want. You're still better off looking into cryogenics for that effect, in my humble opinion.


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## Cryogenifex (Mar 17, 2011)

For a list of FAQ about Co2 jets visit:

FAQ


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