Query on gas in warming cabinet

[Buzzlodge]

I have been gifted and old under counter freezer and am converting it into a warming cabinet.

The refrigerant gas used is R600a which is isobutane, a non global warming gas but highly flammable.

My query is whether heating the cabinet to +/- 40C (or higher in a malfunction) might pose dangers eg by causing the gas to expand, forcing a flammable leak?

Would it be better to bleed it off outdoors before use?

 

[jenkinsbrynmair]

I could answer yes to that

 

[user 6127]

Would it be better to bleed it off outdoors before use?

Absolutely. You can then also get rid of the compressor, and other wiring not needed.

 

[pargyle]

Yes you should get rid of all the existing compressor/wiring etc. not needed for a warming cabinet. The refrigerant is not supposed to be bled into the atmosphere whatever it is ... but you could bleed the isobutane into a PET bottle (it's heavier than air) - then put the cap back on the bottle with a pin hole in it and from a goodly distance light the gas ... as the flame burns down the mixture in the bottle will eventually become explosive and the resultant explosion of the PET bottle is very entertaining. As the products of combustion are just water and carbon dioxide this is a very environmentally safe way to dispose of the butane and blow yourself up in the process ...

You then can safely remove the mechanical bits of the fridge ..be careful with the compressor oil though as it will still have some absorbed Isobutane and will be flammable.

 

[coffindodger]

and blow yourself up in the process ..

 

[pargyle]

and blow yourself up in the process ..

As a kid at school we used to do a similar experiment with coal gas out of the gas tap and a treacle tin ... punch a hole in the bottom of the tin and a pin hole in the lid. Fill the tin with coal gas, light the gas coming out of the pin hole in the lid and it would burn nicely for a minute or so ... until the mixture in the tin became explosive and then it would go off with a bang and blow the lid off.

Like all 14 year olds I was never satisfied and graduated to a large coffee tin which we filled with coal gas ... and we sealed the lid to the the tin ... Now that was something else ... the bang could be heard half a mile away and the tin was blown thirty feet into the air ! Got into a bit of hot water with that particular escapade ....

 

[Newbeeneil]

As a kid at school we used to vdo a similar experiment with coal gas out of the gas tap and a treacle tin ... punch a hole in the bottom of the tin and a pin hole in the lid. Fill the tin with coal gas, light the gas coming out of the pin hole in the lid and it would burn nicely for a minute or so ... until the mixture in the tin became explosive and then it would go off with a bang and blow the lid off.

Like all 14 year olds I was never satisfied and graduated to a large coffee tin which we filled with coal gas ... and we sealed the lid to the the tin ... Now that was something else ... the bang could be heard half a mile away and the tin was blown thirty feet into the air ! Got into a bit of hot water with that particular escapade ....

That was my first chemistry lesson...... the flame from the top of the tin would completely disappear as the teacher explained what was happening re gas/air mixture and some pupils would try to tell him but he would carry on until we all fell off our lab stalls as the lid blew off!!!

 

[jenkinsbrynmair]

As a kid at school we used to do a similar experiment with coal gas out of the gas tap and a treacle tin ... punch a hole in the bottom of the tin and a pin hole in the lid. Fill the tin with coal gas, light the gas coming out of the pin hole in the lid and it would burn nicely for a minute or so ... until the mixture in the tin became explosive and then it would go off with a bang and blow the lid off.

Like all 14 year olds I was never satisfied and graduated to a large coffee tin which we filled with coal gas ... and we sealed the lid to the the tin ... Now that was something else ... the bang could be heard half a mile away and the tin was blown thirty feet into the air ! Got into a bit of hot water with that particular escapade ....

Being a mining community, it was calcium carbide for us - my grandmother's cousin a few doors down used to have a small general store in the 40's and 50's and they sold Carbide for miners' naked flame lamps. Years later I was rummaging around in the loft of the stable and found a half hundredweight cask of it - empty honey jar, lump of carbide, water, screw the lid back on, quick shake then pierce the lid and light - it was like a flamethrower, not often did the jars explode though

 

[pargyle]

What is it about young boys that caused us to spend most of our time trying to blow something or ourselves up ?

 

[E&MBees]

What is it about young boys that caused us to spend most of our time trying to blow something or ourselves up ?

My husband has helped our boys to build rockets during lockdown. They have had great fun learning about physics, maths and engineering whilst scaring the neighbours!