Cure for freezing propane bottles

[roofman]

We use a load of Propane each week through our job and every winter we suffer the same problem of the bottles freezing and reduced pressure as a consequence, this is no good when laying the torch-on felts. This year i have a plan and have made a "Thermabin" plastic bin lined with a foil frost protector for car windshields and then filled with expanding foam around a bottle...foam goes hard and bottle slides out.

 

[plewlandsbob]

Are you going to use something, to cover the top of the cylinder and regulator, as well?

 

[roofman]

Are you going to use something, to cover the top of the cylinder and regulator, as well?

Not needed as they freeze from the bottom up at the same level as the liquid propane, gas going through the regs does not freeze.

 

[m_c]

You do realise that if you insulate the bottle, that the gas will just freeze quicker?

 

[roofman]

You do realise that if you insulate the bottle, that the gas will just freeze quicker?

Cant see how as on warm days they don't get lined with moisture and freeze, plus when in the past we have wrapped them with storage tank blankets they do fine

 

[8ob]

We use a load of Propane each week through our job and every winter we suffer the same problem of the bottles freezing and reduced pressure as a consequence, this is no good when laying the torch-on felts. This year i have a plan and have made a "Thermabin" plastic bin lined with a foil frost protector for car windshields and then filled with expanding foam around a bottle...foam goes hard and bottle slides out. View attachment 470517 View attachment 470518 View attachment 470519 View attachment 470520 View attachment 470521

Good idea, it will outlast any of those flimsy bottle blankets.


Bob

 

[Kayos]

You do realise that if you insulate the bottle, that the gas will just freeze quicker?

The bottle isn't freezing, as it turns from a liquid to gas it removes energy from it's surroundings, this in turn cools the bottle and on cold days this causes the condensation to freeze, this then cools the bottle and slows the rate the liquid changes to a gas and affects the pressure

 

[George A2Y]

I'm no expert but I would think it would be best (up until you start to use it) to try and keep the contents of the cylinder/s warm, approximately room temperature or slightly warmer. Your insulated container could help with that but would be better if totally enclosed. Coupling cylinders together via a manifold would also help as less gas would be drawn out of a bottle at a time, but probably not practical for roof work.

 

[Keith 66]

Some years ago i fitted out a steam launch kit for a customer, i did the engine & boiler beds etc, the launch was then fitted with a propane fired boiler by the customer.
Four 32 pound bottles, two each side of the boiler. Each pair stood in a box that could be filled with water warmed by water from the condenser hotwell in order to stop the bottles freezing up.
I never saw it finished or running. I understand in the Steam Boat Association the boat was nicknamed "Butterworths Bomb"!

 

[rtcosic]

The bottle isn't freezing, as it turns from a liquid to gas it removes energy from it's surroundings, this in turn cools the bottle and on cold days this causes the condensation to freeze, this then cools the bottle and slows the rate the liquid changes to a gas and affects the pressure

Scraping the ice from the bottle helps. Even running a little 'cold' water from a hose over the bottle helps. Anything that helps get heat into the bottle helps. Insulating it and reducing the heat that gets in will make matters worse.
Don't play the torch over the bottle!

What is the flow rate of propane when your torch is running? You can work out how much heat the evaporating propane needs to draw from its surroundings from the latent heat of evaporation at 428kJ/kg.

Electric heat tracing is a solution for fixed installations, but I doubt that's practical in your circumstances.

Frost Protection, Trace Heating, Free Specification & Design

Frost protection and trace heating for any domestic & commercial applications. All trace heating products with free next day delivery. Extra discounts available.

www.frostprotection.co.uk

 

[gaz1]

your in luck tech has changed enough for us nowadays

battery operated warm jackets

battery operated blankets

insulation wont work but a heated insulation will just remember add drain offs

there is heated wires and electric blankets as well

remember these need to be on before you start work so there already warmed up

 

[voipio]

The formation of condensation, and subsequent ice formation on the popane bottle, will actually reduce the rate at which the liquid propane in the bottle is cooled by evaporation of the liquid propane as the gas is used (since condensation and ice formation give off energy, which may seem counterintuitive at first). This will continue until the ice itself becomes thick enough to act as a blanket. What you need, as Gaz1 and others have suggested, is a source of heat, to keep the liquid propane in the bottle at a decent temperature (say 10 to 20degC), using either some sort of heated tape, or heat from another source, such as burning propane from the bottle, but in a safe way that distributes the heat. A heated water jacket would do.

There's this, from the good old US of A:

Gas Cylinder Warmer for 100 Pound Tank - Propane Tank Heater GCW100 by Powerblanket

A maintenance free heating solution, which eliminates the headache of maintaining critical temperatures.

mrshrinkwrap.com

Or this (somewhat lower powered than the one above):

https://www.amazon.co.uk/WXHDYBLANKET-Propane-Cylinder-Heating-Blanket-Quickly/dp/B0CCM8YF4H

 

[Gareth J]

I used to get issues getting the last of the propane out of camping stove bottles. They were stored in a cupboard. No condensation or icing - the cupboard didn't hold much moisture, but the temperature would just drop below the boiling point of the propane.

Open the cupboard door and take out the bottle and it would take enough heat from the air to get the last of it out. With some condensation.

My conclusion is that condensation/icing of the bottle isn't the cause of the problem but is a symptom of the reduced bottle temperature. Therefore I think an unheated, insulated jacket will cause problems.

Would be more effective to have an uninsulated cut off copper water cylinder with some water in it.

 

[Erie Fred]

"Wizz on it"......
Can you paint a few (for wintertime usage) flat black ?

 

[rtcosic]

I was intrigued so did some Googling and a bit of arithmetic

I found a link that stated the gas consumption of a roofing torch was up to:

6.77 kg/h
which is 1.88 gm/s
with the latent heat of 428 J/gm
that is 804 J/s

or the thick end of 1 kW

I was surprised at that. Frost protection tape would not provide anywhere near that.

The cheapest blanket I found in the UK was this one :

Pardon our interruption...

but at only 150W it's a bit small.
But I doubt you run the torch at max continuously so if it is attached at the start of the working day it may just be adequate.

 

[Kram]

As above, you get the same problem, much worse with butane or butane propane mix bottles as used in the small camping stoves. A pot of warm water soon gets them back upto pressure. The problem with butane in winter is that it seems to absorb as much heat from evaporation as you get from heating water so with a 50c limit on the bottle temperature, making a cup of tea and breakfast is a slow and pathetic task.

Problem is that a dustbin 1/3rd full of warm water could take a reasonable amount of gas/time to warm up.

 

[Erie Fred]

Hey it works, that's all that matters.
You did a nice job of it, no cobbling, and it doesn't violate any Health & Safety (or whatever)
rules. Which is not easy to do these days.

Probably makes the tank safer in case it got hit or dropped as well.

 

[Erie Fred]

The formation of condensation, and subsequent ice formation on the popane bottle, will actually reduce the rate at which the liquid propane in the bottle is cooled by evaporation of the liquid propane as the gas is used (since condensation and ice formation give off energy, which may seem counterintuitive at first). This will continue until the ice itself becomes thick enough to act as a blanket. What you need, as Gaz1 and others have suggested, is a source of heat, to keep the liquid propane in the bottle at a decent temperature (say 10 to 20degC), using either some sort of heated tape, or heat from another source, such as burning propane from the bottle, but in a safe way that distributes the heat. A heated water jacket would do.

There's this, from the good old US of A:

Gas Cylinder Warmer for 100 Pound Tank - Propane Tank Heater GCW100 by Powerblanket

A maintenance free heating solution, which eliminates the headache of maintaining critical temperatures.

mrshrinkwrap.com

Or this (somewhat lower powered than the one above):

https://www.amazon.co.uk/WXHDYBLANKET-Propane-Cylinder-Heating-Blanket-Quickly/dp/B0CCM8YF4H

I would not use one of those without a feedback loop to a pressure sensor.
But then again, that's just me.

 

[bourbon]

Just idle thinking, but what about one of those heat pads you get from the chemist thrown in the bottom?

 

[Bullet2012]

The best thing to prevent this happening is.
Go somewhere warm for the winter and let some young fool worry about freezing things whilst on a roof during a cold damp british winter.