Quote:
Originally Posted by Neuromancer
QFT. Even a simple google search reveals it is NOT an easy process. Nitorgen I see some guys say is not necessary.
Let me explain why it is used. Which conversely is why LN2 is so readily apparent.
Whenever you braze a joint on piping or more specifically a closed loop like for instance a Water loop you would use to cool your CPU you have to make sure that loop stays containment free. Because first of all everything is shipped open, some people use tap water and/or dyes. plus whatever other containments existed between the tubing manufacturing process or what not.
Now assuming you know basic cooling philosphy you know that SS/Cascade are type of "phase change" cooling.This is the driving principle behind heatpipes for air coolers. Except on a much more volatile level.
Compared to water it is backwards
In a phase loop the heat comes not from the CPU or GPU or whatever you are putting the evap on . The heat comes from compressing the liquid within the loop. In this case special gas with a very specific range of temperatures.
they add oil to the loop to add the compressor, think of it as a single cylinder motor or other wise a an old vaccuum bell jar like you saw in chemistry class
Oil in the phase loop, which is why you leave a air conditioner etc to settle before you turn it on. lubricates the cylinder/compressor. If it gets into the rest of the loop it sits and you do not want that.
In a water cool loop the idea is that heat is transferred to the medium (well honestly it is always transferred to the medium. You cant ADD cold you can only remove heat) which moves the water to radiators that disperse the heat.
In a phase change system. The gas is compressed to a liquid here is the weird part. Compression adds heat, so the coils coming off a compressor are warm. The go through a radiator to shed heat but are not allowed to expand. When they are allowed to expand the absorb so much heat that they can reach sub ambient temperatures. They flow back to the compressor and repeat teh process.
Water however is bizarre. Only naturally occurring substance that expands when it gets cold. IT also make a great insulator. Which is why icehouses are so popular in the sbubzero north. Since water is in EVERYTHING including air, you have to get rid of it in the pipe lines. Nitrogen (is a non combustible gas) that has a very low boiling point. It is heavier than air (despite air being 70% nitrogen) and force out other impurities as it is passed through a line.
Soldering or brazing a joint benefits from passing nitrogen through it in two ways. First it will not develop high pressure because it is already a gas. Secondly it discharges containments through the loop. Most importantly it is a basic gas And thus when heated gives off nothing. A process called "inerting." Which basically means the first two things.
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YEAH OK (Crickets)
HAAAAAA, you guys blow me away!
Why to much Information in there for ma lil brian, I used to do automotive A/C charges but never was schooled for it, what I would like to try is to use it in a cooler like Witchdoctors first replied, instead of making a mount. I can brazz it closed with a tourch and rod, I took auto body class we used to brazz the metal rust holes closed. Plus I like blowing stuff up too .............
