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View Full Version : Three-stages cascade system



Sk_rmouche
19-06-2012, 01:55 PM
Hello everyone !

I'm new here, but read so much topics in this cat', we learn a lot !
Excuse me in advance if I make mistakes in English, I'm french :)

So my project consists in a cooling/heating chamber that I'm currently building, here's a picture :

http://img849.imageshack.us/img849/8895/dscf8214k.jpg (http://imageshack.us/photo/my-images/849/dscf8214k.jpg/)


On the paper I want to be able to bring down the internal T° to -130°C ( that's what I'm aiming to at least ... ). I already got my two first stages in run, but I'm stuck about R14, hard to get some, and expensive. Some people told me that I could use a blend of methane and ethylene instead; of course it'll be tacky to tune, but I'm seriously considering that option, what do you think guys ?

First stage run with R404a @ -40°C with R404a TXV Danfoss
Second stage run with R23 @ ~ -80°C with R23 TXV Danfoss
Third stage should run on CPEV, if it leaks I'll turn over to EEV with PID regulator, I think.

Thanks, and have a nice day !

Vincent.

Sk_rmouche
21-06-2012, 11:05 AM
The inside of the chamber :

http://img405.imageshack.us/img405/5448/210620121165.jpg (http://imageshack.us/photo/my-images/405/210620121165.jpg/)