residue R404a

[tralex]

Hello, experts
I use for work R404A from cylinders.
Each cylinder contain 10.9 kg of refrigerant.
In liquid phase its components R125 / R143a / R134a is in ratio 44% / 52% / 4%
When I charge refrigerator ,
amount and pressure of refrigerant in the cylinder will decrease ,
and once some components will vaporize in cylinder,
and ratio between components get broken.
So a substance in the cylinder will not be R404a.

In view of the aforesaid let me ask some questions:

How much kg of refrigerant I can take from cylinder ?
What should I do with residue blend ? Can I use it for charging?

Thanks for any advice

[LRAC]

How much kg of refrigerant I can take from cylinder ?
What should I do with residue blend ? Can I use it for charging?

Thanks for any advice

Hi Tralex

With all blends you should be charging systems with liquid and not vapour from the bottle. The vapour in the bottle will always be their unless you put the bottle in a freezer each time before use(and then you'll still get vapour).

None of us can do anything about the gas % mixture in the vapour and so liquid charging is the only way to try and get the full % mix out.

Kind regards
Lrac

[NoNickName]

LRAC is correct, and for your last question you should not use more than 90% of weight of the refrigerant content.

[frank]

LRAC is correct, and for your last question you should not use more than 90% of weight of the refrigerant content.

Unless you are putting the whole cylinder charge into the same circuit.

[NoNickName]

Unless you are putting the whole cylinder charge into the same circuit.

No, since part of the gas will remain in the cylinder anyway. The minimum pressure in the cylinder will be the suction pressure.

[Electrocoolman]

Use R507 (AZ50)....no worries then as its an Azeotrope.

[Dan]

Walmart, Winn-Dixie, Publix use R404a as their HFC. This covers about 75% of the supermarkets in the Southeast USA. It cannot be all that bad.

[NoNickName]

Electrocool is right. 507 is much better than 404 and it doesn't have the problem of oil carry over.

[tralex]

Thank you gentleman.

How you recovery residue refrigerant?

[NoNickName]

Thank you gentleman.

How you recovery residue refrigerant?

You don't. Just close the valve and return the cylinder to your supplier.

[taz24]

Thank you gentleman.

How you recovery residue refrigerant?

Pump the system down with the cylinder attached and draw the cylinder pessure down to the lowest you get when pumped down (about 0.2barg).

Should do the trick. any lower and the thing would be on a vacuum.

Cheers taz.

[frank]

No, since part of the gas will remain in the cylinder anyway. The minimum pressure in the cylinder will be the suction pressure.

Exactly the same even if you charge as a liquid

[NoNickName]

Exactly the same even if you charge as a liquid

No. The equilibrium pressure in the cylinder is different than the suction pressure. If the cylinder is warm, than the pressure in the cylinder is higher than suction.

[frank]

No. The equilibrium pressure in the cylinder is different than the suction pressure. If the cylinder is warm, than the pressure in the cylinder is higher than suction.

So are you saying that the vapours left in the cylinder following liquid charging are in proportion to the constituant parts, but are not in proportion when charging a full cylinder as a vapour?

[NoNickName]

So are you saying that the vapours left in the cylinder following liquid charging are in proportion to the constituant parts, but are not in proportion when charging a full cylinder as a vapour?

No, I don't. Actually I use the refrigerant down to the very last drop. My habits have nothing to do with good practice, though.

[The MG Pony]

what if you fire a bit o nitrogen in there and charge only liquid? Then technically all the refrigerant aut to be forced back in only as liquid phase due to artificial pressure the nitrogen induces. Thus you should get no fractioning occurring.

[Dan]

Electrocool is right. 507 is much better than 404 and it doesn't have the problem of oil carry over.

Is this documented, or just an opinion? The refrigerants are so similar, I am surprised at this observation.

[NoNickName]

Is this documented, or just an opinion? The refrigerants are so similar, I am surprised at this observation.

What do you mean by documented? We've built chillers with both refrigerants, if it can be considered documentation, yes it is documented