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Name: Rick
Status: Student
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I was wondering how a DuPont's Freon (TM) recovery system works. More specifically I was wondering how an automotive technicians air conditioning recycling machine takes DuPont's Freon (TM) out of your ac system in your car and stores the captured r12 in a container more as a liquid, not a gas.

** I might be repeating information that you already know, but here goes. **

1.) I've never seen them actually recycle the material. However, from what I've been told they evacuate the system and continue to pull a vacuum on it for 5 mins, or so. I believe they also charge the system to a high pressure to "rinse" the air. They will finish by pulling a vacuum on it for quite some time (30-35 mins). This is to help boil off any moisture that might have gotten in the refrigerant line. At the vacuum pressures (1-2 psia) they are generating, water will boil off fairly readily (well below 212 °F).

2.) Where do they evacuate it to? I believe they use a compressor to recompress the R12 into a holding tank. At this point the R12 will undergo a phase change from gas to liquid. To understand why and at what Temp and Press., you need to consult a PVT diagram of the material in question. Im sure the reason why they convert from gas to liquid is out of convenience.


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