I have a lecture bottle of CO2, and a kit for making dry ice from a cylinder. However... the kit specifies that you must use a cylinder which has an internal siphon, which is designed so that you draw from the liquid portion at the bottom of the cylinder. What i'm wondering, though, is whether it'd be safe to simply use my lecture bottle, but upside-down.

 

what do you guys think?

two aspects to this that I can come up with:

 

1. the first thing I can imaging going wrong is that the CO2 becomes solid after the valve, effectively blocking the exit. This will then suddenly un-block when the CO2 heats up. I don't know how the exit of the lecture bottle looks (the valve, pipes and pressure gauges)... so I don't know how likely this is.

 

2. Is there any difference between what you want, and the cylinder with internal siphon?

I'm breaking my head over this question, but I cannot come up with a good reason why it would be more dangerous than the cylinder with internal siphon, other than that you're not able to put it down easily without turning it back up. The internal siphon cylinder can be put down without turning it around, and is therefore probably easier to handle.

the kit itself should take care of aspect 1, and even if it gets blocked... it'd just be like a sealed cylinder again, wouldnt it?

 

aspect 2, the lecture bottle is much smaller... it can be held in one hand

Yeah, I figured that both points were not going to cause major problems.

 

I just gave my thoughts on what I thought could possibly go wrong. Then you can go and estimate whether those things are a real risk. It never hurts to come up with possible disaster scenarios to see if you have thought of everything.

aspect 2, the lecture bottle is much smaller... it can be held in one hand

 

wear good gloves.

wear good gloves.

 

yes i've learned that lesson the hard way several times through absent-mindedness