Propane tank frosting and inefficiency

[BrewOx]

Hey everybody,

I recently bought a new, more powerful burner to boil my wort since at best my old one never really got the wort to a roiling boil. That being said, I was making a batch of beer yesterday with a 90 minute boil when I noticed that even though the burner was almost fully open, the boil was slowing down. I happened to take a look at the propane tank and noticed that it was covered in a layer of frost about 1/4" thick. I picked up the tank to see how full it was and when i picked it up and shook it, the burner all of a sudden started really pumping out again, however once I let it sit the burner would slow down again. Is there something I am doing wrong? I don't want to have to sit there shaking a propane tank for an hour or more just to ensure that my boil remains constant. Any advice would be most welcome!

 

[ColoHox]

Nope, pretty common, it has to do with the pressure in the tank at low temperature. On cold days I have to keep my propane tank in a tub of warm water to keep the flow going strong.

 

[LordUlrich]

Some options:
Slow down the burner (after you have a good boil), you should not need it full power to keep a boil going.
Set the tank in a tub of water
they make adapters that allow you to feed 2 tanks to a single regulator, it will slow down the flow from each tank and keep them from frosting over.

 

[raouliii]

A word of caution. Put the tank in a tub of water before you start the boil. Additional water can be run through the tub to add heat.

Warming up a very cold tank with a stream of water can create a lot of frightening creaking noises from the tank. Quick expansion of the tank cannot be good for its integrity.

 

[poptarts]

use the tank to cool the wort, win win.

 

[BrewOx]

Thanks for all the responses, everyone!

Will placing it in a tub of water really do the trick?

Also, I do have multiple propane tanks so maybe the splitter thing would be the best idea. Any idea on where I might find one?

 

[LordUlrich]

A tub will help, it acts like a radiator, and adds thermal mass to the system.
I'd check at a propane place (like a place that delivers propane to rural properties). You could also try a rv shop.

 

[billl]

Honestly, you should not need to run a single burner at such as level as to freeze a tank in summer. Are you sure you are getting full combustion? Have you got the burner a reasonable distance from the kettle? Wind shields? Dropping the tank in some water will defrost it, but the real problem is that you are using CO2 at a very high rate. That will get expensive pretty quick.

 

[sloanfamilydsm]

The next time you have your tank filled ask them to purge your tank to remove any air inside. Exchange tanks are especially bad about air in the tank.

When a new tank is filled for the first time, the air is supposed to be purged out. Over time air can re-enter the tank and will need another purging. The water in the air will freeze inside the tank causing restrictions (liquid propane is like -40 degrees).
This happens a lot in the grilling world

 

[raouliii]

...Will placing it in a tub of water really do the trick?...

Yes. The reason it is getting cold/frozen is that the burner is drawing off vapor at such a high rate, the liquid is losing more heat than it can absorb through the steel wall/ambient air, junction. The drop in liquid temperature also results in a vapor pressure drop, hence the low flame. Replacing ambient air with water allows heat to transfer into the tank at a higher rate. The water will lose heat over time, so a steady flow of fresh, "normal temperature" water needs to be provided over the long haul.

When you pick up the tank and slosh the liquid around, the warm steel above the frost line immediately warms up some of the liquid which boils into vapor, increasing the vapor pressure, hence the rush of flame.

..... Dropping the tank in some water will defrost it, but the real problem is that you are using CO2 at a very high rate.....

I use C3H8 in my tank.

 

[BrewOx]

Thanks for all the help everyone.

However, now I have even more questions!

When I use tanks of gas I use the ones that I can switch out for at Home Depot. Where is it possible to get all these specialty gases and stuff for and how do they work better?

 

[outside92129]

I painted my tanks black and keep them in the sun during brewing, it helps a bit. I don't like to switch out tanks - it's a rip off (vs refilling... see other threads) and i'd lose my paint job!

The other gasses you see above... just google them

 

[BrewOx]

Migmtmitmminmikmimmymhiouoollp

 

[BrewOx]

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[BrewOx]

I'mpuhm

 

[CastleHollow]

Having a seizure?

When I use tanks of gas I use the ones that I can switch out for at Home Depot. Where is it possible to get all these specialty gases and stuff for and how do they work better?

Propane or air gas companies in your area will refill your tanks. You can also upgrade to a larger bottle, which will save you some money and time in the long run.

 

[GrogNerd]

you want to first cover the tank with a thin layer of frosting

it's called a crumb coat & it makes it easier to apply the final coat.

 

[kombat]

This is bizarre - I've never had a propane tank frost over on me. I didn't know it could happen. I've brewed over 70 batches, including some during the depths of a Canadian winter when it's been -4° F outside, and I've never had a problem. It sounds like the OP is draining propane from his tank at an incredible rate if it's actually causing the tanks temperature to drop below the freezing point in the summer.

 

[BrewOx]

Sorry about the weird texting everyone, somehow in my pocket it accessed this app and wrote those posts. My sincerest apologies.

This is bizarre - I've never had a propane tank frost over on me. I didn't know it could happen. I've brewed over 70 batches, including some during the depths of a Canadian winter when it's been -4° F outside, and I've never had a problem. It sounds like the OP is draining propane from his tank at an incredible rate if it's actually causing the tanks temperature to drop below the freezing point in the summer.

To be honest, it only started happening when I got this new burner so it was very new for me too.

 

[raouliii]

This is bizarre - I've never had a propane tank frost over on me. I didn't know it could happen. I've brewed over 70 batches, including some during the depths of a Canadian winter when it's been -4° F outside, and I've never had a problem. It sounds like the OP is draining propane from his tank at an incredible rate if it's actually causing the tanks temperature to drop below the freezing point in the summer.

In south Louisiana, we see it at just about every crawfish boil. :rockin:

 

[Stealthcruiser]

You need some good humidity up there in Canadia!