# Ice Buildup Around Lpg Bottle



## notung (22/9/09)

Yesterday I was brewing my pumpkin beer for the VIC swap. By the end, I was boiling the wort in the rain and must have looked like a weirdo squeezing the no chill cube in the wet, after dark. As I was packing everything away, I noticed an ice buildup around the base of the LPG bottle. At first I worried there had been a leak or something, then I wasn't sure. I 'googled' it and somewhere it said that can indicate that demand for gas is greater than supply...(?) I wonder if that means I'm nearly out, or if the spiral burner wants too much fuel?

Anyone encountered this before and can explain the science?


----------



## OzMick (22/9/09)

Inside the bottle, the LPG is, as the acronym suggests a liquid. You cook with the vapors, so inside the gas bottle, the LPG is actually evaporating. Evaporation requires energy (just like the water you're trying to boil off in the kettle), so the gas bottle pulls it out of the air, and because the boiling point of LPG is lower than ambient (in most conditions), it can pull the energy from its surroundings. So the bottle surface cools down, and then water condenses, which is the opposite of evaporating, so this contributes energy to the bottle too.

So it is perfectly normal. And also goes a way to explain why those portable gas stoves in camping shops perform so horribly in cold weather; the little gas canister has difficulty drawing in enough energy to vaporise the gases contained within, and can take ages to boil water as a result...


----------



## mash head (22/9/09)

Yes both explainatoins are true. It souds like you are nearly out of gas. Lpg is stored as a liquid and as it vapourizes it gets very cold. If you draw more gas pressure than the bottle can supply it will vapourize quickly and make the gas left inside quite icy. Maybe turn your reg back a couple of notches but its nothing to really worry about until your out of gas.
Greg


----------



## Leigh (22/9/09)

Perfectly normal, although frustrating at times notung.

To add to Ozmicks, once the outside of the cylinder has ice on it, it can no longer draw the "energy" through the cylinder to evaporate the gas at the rate required, hence the comment that you found that "the gas demand is higher than supply". This effect can cause the flame to reduce in intensity or even go out.


----------



## andreic (22/9/09)

I have seen this happen before also, on a wet brewing night with a gas bottle nearing the end.

But... this thread simply cannot go any further without a link to the Jet powered beer cooler.


----------



## notung (23/9/09)

andreic said:


> But... this thread simply cannot go any further without a link to the Jet powered beer cooler.



Wow. Well, that explains it for me. Glad to see someone putting the knowledge to practical use as well.


----------



## matt white (23/9/09)

The line of ice also indicates how much liquid gas is left in the bottle.


----------

