Refrigerant recovery

[chillyblue]

Hi

I remember seeing an article re- refrigerant recovery and it being about a fast method of recovering refrigerant from a system, from what i can remember it was saying that there is a method not many people use. Using the recovery machine a certain way by a push pull method, does anybody know about it and how to connect the lines??

CB

[Brian_UK]

Push-Pull, quite common.

You need a twin valve recovery cylinder.

System liquid line connects to liquid valve of cylinder.

Vapour side of cylinder connects to inlet side of recovery machine.

Discharge side of recovery machine connects to vapour side of system.

Operation - You are 'pulling' vapour from the cylinder and 'pushing' liquid from the system.

Also helps to keep temperatures down.

[Argus]

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Another perspective on reclamation units. Here’s a unit not, I venture, for tin-and-wind splits.

This so-called Zugibeast will pass about a metric tonne or more per hour while the system is still in operation.
Here are some links. This is a heavy duty refrigerant cleaner / reclaimer.

http://www.hudsontech.com/

http://www.processengineering.co.uk/Articles/291789/Refrigeration+refresher.htm

http://www.engineeringnews.co.za/article.php?a_id=95062

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[chillyblue]

Cheers Brian

Would that not just keep pump the gas in various states from one place to another, is that a cleaning method?? or is it used to actually remove gas from a system??

This is the way i see it, if the unit is pulling vapour from the bottle your reclaiming into. That vapour is then condensed by the reclaim machine and put back into the plant you trying to reclaim from????:confused: so are you not just moving it around??

CB

[Brian_UK]

Hi CB,

I used to think that as well, it seems right...

It doesn't always work on some A/C systems because of the location of the access ports.

The amount/quantity/volume of vapour being moved is less than the amount of liquid that will be pushed out of the system.

The lower pressure in the cylinder helps to keep the liquid in that state so you do not pull out more than you put in.

Another way of looking at it is to consider a small bottle with water in it and a drinking straw. If you blow down the straw all that happens is that bubbles come out through the water.

If you cover the bottle neck with your mouth and blow then you will eject water through the straw; likewise if you sucked from the bottle neck all you would get is more air through the straw not water.

Imagine the straw connected to the system receiver and you will have liquid drawn in with only vapour taken from the bottle.

[chillyblue]

Thanks Brian

I'll give it a go next time
great explanation

Cheers

CB

[marc5180]

I use the pus pull method on larger units, get the refrigerant out a much much quicker

[Karl Burke]

Hello CB

Thought I would just mention that you are right when you say"That vapour is then condensed by the reclaim machine and put back into the plant"
This will only occur when you have the recovery machine set to "recover"

If you want to use "push pull" method it must be set to purge or its equivilant depending on your machine.

The difference being that it will now bypass the condensor located in your recovery unit and provide discharge pressure in to your system.

This now creates the pressure difference required to move the liquid into your cylinder from the system remembering that the cylinder is connected to the suction side of the unit.

KB

[chillyblue]

Hi Karl

I have a recovery or self clear, i assume you would have to have it on self clear??



If you want to use "push pull" method it must be set to purge or its equivilant depending on your machine.



Is there any danger if the liquid entering the reclaim cylinder has been sub-cooled??

When the liquid has been recovered, can you complete the whole process this way or do you have to change back to the standard recovery method??

Cheers

CB

[Brian_UK]

Normally once you have pushed all the liquid out you need to swap your hoses around and complete the vapour recovery.

[chillyblue]

Cheers Karl

I'll give it a go next time

CB

[bruisermac]

mid seat ur king valve and have the compressor pump it out.