Freezing Propane Tanks. A Different Solution

[Frosty]

Increasing the surface area exposed to ambient air will prolong the time propane will stay above vapor temp. Increasing the area in the tank does nothing except maybe increase the chance the tank will tip over and start squirting liquid propane through the burner. This is a B A D thing.

100lb tanks can be had for reasonable at yard, garage, etc. sales. Just look them over carefully for damage and the date on the inspection tag. 

Frosty The Lucky.

[Mikey98118]

I agree with with this man's application being as safe an answer as there is likely to come along. I also agree that safety codes must be followed. However, I doubt that the code applies to this particular case, because the heat source is controlled. Furthermore, I paid for a copy of the code twenty years ago, and this subject was not mentioned in it then; I doubt that it is now.

[Candidquality]

Not trying to stir the pot, 100% with buying the proper size tank, and more importantly, buying the right size burner.  Just had a passing thought.  Appreciate the confirmation it would not make any real difference tipping the tank (excluding the danger).  One more way we know it would not help.  

[George N. M.]

FYI, with my modified Sandia forge I have had 20# tanks "freeze" up but have never had the problem with 30# tanks and larger.  A full 30# tank is about all I can carry around.  You would think when any size tank is getting low the cooling vs. mass of liquid remaining would result in the liquid dropping below vapor tempertature but I have not seen that happen.

"By hammer and hand all arts do stand."

[Mikey98118]

4 hours ago, Candidquality said:

Appreciate the confirmation it would not make any real difference tipping the tank (excluding the danger).  One more way we know it would not help.

No, it would not help at all. An important factor is how fast you use propane out of a given tank, versus the tank's size. Another factor is how cold ambient air surrounding the tank is, because it is heat from that air that is being transferred through the cylinder wall to raise the temperature of the liquid propane. Finally, as the tank becomes seriously depleted the amount of liquid propane that is contacting the cylinder wall becomes less and less; giving the same result as a shrinking cylinder would; less heat transfer from the ambient air.

[BeaverNZ]

On 7/16/2020 at 9:29 AM, BeaverNZ said:

Well I am getting well along with my bottle warmers for my two 45Kg cyl,

Just an update with my bottle freezing or pressure drop due to the bottles getting very cold I have found so far I havent needed to use the fish tank heaters though the bottles do get alot of condensation showing where the gas level is when the level is high enough. the extra surface area outside the water tank and the better heat transfer of the water to the bottle is working well. another plus for putting the bottles in the liquid is if you have the water level at 330mm deep with these bottles they float at that level so the felt weight of the bottles is the remaining amount of gas.