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Freezing Propane Tanks. A Different Solution


maddog

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Does not apply and won't work. The propane is stored as a liquid in the tanks, with propane gas above the liquid surface. When the pressure drops, more liquid evaporates to gas until the tank pressure is restored. If you manifold two tanks together, you will equalise the pressure between them, but that won't transfer liquid propane between the tanks. For manifolds to help against freezing, there needs to be liquid propane in both the tanks. That gives you more surface area to warm up the propane liquid that cools as evaporation takes place. 

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Sorry, I should have included a citation to the question which I answered. For the reference, the question was whether it would work to add a second empty tank to the reservoir. The new tank wouldn't add new liquid propane, thus having much effect on the time to freezing.

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  • 1 month later...

Has anyone tried this as a solution to bottles freezing That is a Aluminum box with the bottles sitting in it and filled with an antifreeze solution to stop corrosion with around 3-500 watt fish tank heaters and a submersible pump to circulate the water. The temp of the heaters cannot be set higher than 20 deg centigrade and even in the unlikely event of thermostat failure the low wattage could not over heat the bottles

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Not that I know of, I've tried 1,500 watt magnetic engine heaters stuck directly to the tank and two (3,000w worth) on one tank only prolonged useful time. Putting the tank in about 15gl. of water in the slack tub kept it going all day. 

I don't think your idea has enough output to work but I'm wrong often enough I won't be too surprised.

Frosty The Lucky.

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Yes that maybe the case Frosty but I can just add more heaters if the need arises, I was thinking this way to keep the wattage to the mininmum from a saftey point of veiw so not to have a possible bottle venting in the shop and the water was to give more effective heat transfer i was thinking of maybe a water depth of 300mm or so 

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This is not about a propane tank on a forge but on a gas grill. I was all hot to trot to do me some grilling Friday night! My most wonderful Bride of 22 years had outpatient surgery on Valentines day and I wanted to make it better with a nice meal. So I came back from the store with shrimp, salmon, mushrooms and little sweet peppers to put on the grill. 

I had not stopped to think about the fact that is was 23 degrees the night before, the dog water was still frozen and the grill tank had no sun on it do to being under the grill cover. 

Needless to say there was no grilling in the Seemann House that night. Yup, it was a rookie IFI miscalculation. 

Yesterday I left the tank in the sun until 2 pm and we had a mixed grill dinner that could not be beat. 

My wife is doing well but I hate that it had to happen on Valentines day.

Take care all., 

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  • 4 months later...

In Regard to the 1st original post of his tank freezing up.

I had a similar issue with an aluminum smelter/furnace it turned out I was using a low pressure appliance regulator valve. When I changes it out to a full flow adjustable regulator my problem was solved.

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Well I am getting well along with my bottle warmers for my two 45Kg cyl, There are two 300 watt heaters with a circulating pump all for heating fish tanks and submursable. The tank will be filled close to the top with antifreeze added mainly to stop corrosion but also the unlikely event of cold enough frosts (It has happened with other things in the shop) to freeze the water and damaging something. I was going to put it on wheels but i think I will leave it as is and shift it with the forklift when the need arrives

 

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21 minutes ago, Frosty said:

How cold does it get in your part of New Zealand

It has been a bit cold I measured -12 cent the other morning but it gets up to about 8 to maybe 12 deg cent in the afty my burner have two .9mm jets and maybe Im impaitent but run the presure about 15 to 20 psi and when i was doing the conrods I had it up to 30 psi That was really cranking out some heat. Our Lpg is mostly butane with some propane I believe and in the winter there is a bit more propane added. Even with both bottles paired after an hour or so the pressure drops to a point where I cant get the req pressure and there is a coating of ice on the outside of the bottles, Butane has a higher boiling point than propane 

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Yeah, butane has a much warmer freezing temp than propane and running all 4 burners I don't draw near the gas you do.

Living in cold country myself, I'll be interested to know how it works for you. 

Frosty The Lucky.

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  • 5 months later...

I'm aware one doesn't become smart until they have a high post count but what hey,I'll jump in non-the-less.  I think different people are experiencing different issues but all are being put under a single heading as"freezing".   More specipiclly,there's two common problems that cause burners to stop functioning(either burning lower or going completly out.  What has been discussed is rapid drawdown causing tanks to frost which doesn't neccessarily effect burners but if burners deminish,warming tank will indeed restore pressure and normal operation.  As has been suggested several times,2 interconnected 20lb tanks expose more surface than a single 40 lb tank and help's with rapid drawdown.  To answer the question about pairing with empty tank,it helps or you can get better result if needed by transfering some liquid.  To transfer liquid to empty tank,with tanks joined by hose and both vlves open,hold full one upside down above empty for a few minutes.  Don't store or transport full tanks inverted nor laying on side. You can fix fosting with a 2 stage regulator and/or liquid draw tnk with vaporizer.   A totally different but more common issue is frosting of regulator which usually shut's burners down.  If the regulator frosts or become's ice cold then burners go down,the tank alomost certainly has moisture in it.  Even the tiniest drop of water turn's to ice and plug's orfice in regulator.  It's often difficult to see frost so look quick before it go's away.   A supplier can fix it but often refuse and insist you buy a new tank or have yours recertified.   If you want to fix it yourself,warm the regulator as needed to keep it functioning until tank is empty.  WARNING wear disposable gloves and do not get even one drop of liquid on clothes,garage floor or anything else you don't want to stink for 6 months to a year (you can not wash it off).  Set tank upsidedown overnight then without tilting any more than can be helped,reach under and open valve.  Let liquid drain until it stop's dripping.   Set container up-right and pour 1 or more ounces of denatured alcohol into tank then immediatlly close valve.   The few drops water remainig in tank amalgamate with alcohol to form liquid that won't freeze if it reaches regulator.

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  • 1 year later...

I've only seen a couple of mentions of this as a way of eliminating tank freeze, but I just built a two-tank manifold that draws from two tanks at once.  Haven't had a problem since.  Of course, the fact that I live in Florida may have something to do with that, but even when the temps are below freezing, the tanks don't freeze.

I finally got a 100# tank sitting outside the shop, and ran a line through the wall to a couple of quick-connects inside; that works well, too.  I modified a couple of forge burners to use for blowtorches, and put a few quick-connects around to hook them up where I want to use them.

 

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  • 5 months later...

are there any idea about using any heater and pressure switch?

just build 80watt 12v heater embeded on alumium that i cast in bottom empty gas tank without connector attached.

its work but not enough, i need bigger wattage heater.

safety issues i think with corect pressure switch it will pretty safe, i just need find that correct pressure switch.

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  • 2 weeks later...
  • 6 months later...

How about simply tilting the tank?  At what point in the tilt is it safe for a properly fully filled tank to be tilted?  Even at the 80% full mark(proper full fill), we should be able to tilt 45 deg

Since we are concerned with the surface area.  Tilting would be useful to increase the liquid surface area, as long as you don't tilt so far as to pickup liquid.  Tank would need to be 45% full or less to tilt to 90 degrees. 

on a 20# tank:

Flat gives you approx. 113in^2

Tiltilg at 45deg would give you 122in^2 up to 151in^2 at the widest spot.  

Then tilting to 90% when below 40%fill would give you 153in^2 for a while. 

Bottom of the tank the angle decreases but it would still be better at 90deg for all. 

 

Taller tanks the number would go way up the further tilted.

 

Dangers in picking up liquid?  Would it damage the regulator? Just blow out your burner? 

I'm sure someone here could chime in with the dangers and pitfalls.  But since the safest acceptable method discussed seems to be dropping it in a bucket with a few inches of water, why not make it safely hold your tank at better angles to increase surface area?  

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Maybe I am missing some of the physics here but I am not sure how increasing the surface area of the liquid would keep the remaining liquid propane from freezing.  As I under stand it, the process is that the liquid propane evaporates into propane gas which, under the tank pressure, feeds our burners.  The evaporation in the tank is an endothermic process which cools the remaining liquid.  When the temperature of the remaining liquid propane drops below the vapor point of propane evaporation stops and the tank is "frozen" (even though the remaining propane is in a liquid, not solid, state).

Placing the tanks in water gives a larger thermal mass which slows the cooling process.

The "freezing" becomes more likely as the level of the liquid goes down because there is less mass and what remains cools faster.

So, unless I am missing something, increasing the surface area would only spread out the area for evaporation.  Because of a constant pressure the same amount of evaporation and cooling would be going on, just spread over a larger surface.  The mass of liquid which is being cooled by the evaporation remains the same.

Either I am missing something or tilting the tank would make no difference IMO.

"By hammer and hand all arts do stand."

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