Plumbing in the cold...

We are gonna be cutting and brazing today...yeaaaah we're gonna stink up the house...Yeaaaaah
Some of the tools of the trade include:
a pipe cutter(ridge) the best I ever used...
a tubing bender(cheap and inefficient, wish I had gotten a 20 dolla one)
a High heat torch head (capable of handling MAPP gas) for brazing connections
a cylinder of MAPP gas
a gross of flux coated brazing rods...


First we have to have a place to fill and vent the refrigerant. This is done through a set of service valves.
There in one on the High pressure side or the liquid side and
One on the Low Pressure side or Vaccuum.
This brass fitting is put into service by way of a "Tee" and has a stainless steel schrader valve core inside.
The cap also serves as the wrench and has a rubber seal in the top, should the valve itself leak refridgerant.
There are many things like this little detail that I have found common with refridgeration systems.



On the high pressure side gas refrigerant is pumped into the top of the Condensor. There is where as the name implies, the gas will be "condensed" and changed into a liquid.
This is where the internal heat is removed and the now liquid refrigerant moves on through a dryer/filter and then on the the evaporator.
The amount of refrigerant as well as rate of refrigerant is critical in tunning these systems for efficientcy. Metering of the refridgerant is done by the capilary tube in this case. It s a small diameter copper tube of a caculated size and lenght...



From the Capilary line the liquid refrigerant is introduced into the evaporator. The lenght of capline is usually fashoned in coils and tucked safely away from vibration and spinning fans etc...


Now in the evaporator the Liquid refrigerant is introduced to a larger volume of space. This is where the phase change to a vapor happens. Because of the ultra low boiling point of that refrigerant it turns to a gas creating a super cold environment. The evaporator in this system is made of 3/8"I.D. copper coils and 11' of them looks like this...



We'll be spreading them out and soldering them into a Custom Made Copper reservoir manufactured by CasperTG right here from Pimprig. Thanks man I knew I could count on ya...
Here is another view of the expanded evaporator and capline w/ filter in place

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From the outlet of the evaporator and in a gas form under vaccuum the refrigerant moves past another sevice vavle and filter / dryer and into the compressor to start the loop again.

Well there you have it, cut , brazed, and ready for some refrigerant to be circulated through the veins of the "Bone-Chiller" chiller...ZENNZZO style

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So..Compress liquid..let it expand in a chamber, it turns to gas, gas makes the metal cold (heat transfer) and then you vaccum out the liquid it turns back in to?

I'm trying to wrap my brain around this, and it's late and I'm tired...
Love the torch...Gotta get me one!!!

Quote: Originally Posted by $SOLID$ Necro So..Compress liquid..let it expand in a chamber, it turns to gas, gas makes the metal cold (heat transfer) and then you vaccum out the liquid it turns back in to?

Once the liquid "phase-changes" to gas, it stays as a gas under vaccuum until it reaches the compressor. Next, the gas is compressed into the "condensor" which changes it back into a liquid, then it starts the cycle again...

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Jesus, man. You truly are a living immortal, you know that?

Anyway, just a quick question. Since you are using copper tubing, are you going to be able to coat it to prevent corrosion? Also, doesn't copper attract condensation on the outside due to the coolness on the inside? I know you've already thought of this, but I was just curious.

Rob

Quote: Originally Posted by Rob Jesus, man. You truly are a living immortal, you know that? Anyway, just a quick question. Since you are using copper tubing, are you going to be able to coat it to prevent corrosion? Also, doesn't copper attract condensation on the outside due to the coolness on the inside? I know you've already thought of this, but I was just curious. Rob

Copper refrigeration tubing is used in all the phasecooling applications that I've seen. Other than anhydrous amonia refrigerant all of the common ones like r-404a, r-134a, r-408a do not react with copper. The frigrator in your kitchen right now is probably a R-134a phase change stystem.

As far as condensation...and surface that is colder than ambient in a air filled area will condensate.
Natrual phasechange if you will. Water that is disolved into the air we breath will condense on the surface of a cold beer bottle.

Insulation will not only keep the condensation from forming on the surface of the system, but is Essential in it's efficiency. Better insulation means less cold out and less HEAT in. This is also a form of tunning, that way we can concentrate the heat transfer where we want...

Great questions, Rob...sometimes I miss those things when I'm describing systems...

Do you have any experience in anhydrous ammonia handling Zennz? Just curious because it is used a lot around here by farmers during the fertilization process, I might be able to purchase some for you.
Of course, the farmers would probably think I was going to use it to make meth, but maybe if I pointed them towards this thread (if they have internet access) they might agree to come off of some.
I doubt it, but it may be worth a try if you could use it.

Quote: Originally Posted by godfoot Do you have any experience in anhydrous ammonia handling Zennz? Just curious because it is used a lot around here by farmers during the fertilization process, I might be able to purchase some for you. Of course, the farmers would probably think I was going to use it to make meth, but maybe if I pointed them towards this thread (if they have internet access) they might agree to come off of some. I doubt it, but it may be worth a try if you could use it.

Thanks but no thanks...that would be in violation of more laws that I would be willing to list...fertilizer grade anhydrous amonia would be different than refrigeration grade as well. Handling of that same product is a hassle to say the least. We used it on the fleet and in blast freezers for fish processing.
It is being phased out because of it toxicity, unfriendly enviromental issues, and of course the abuse issues.

I'll be using r-22 or 408a in this system, and I'll be having it charged commercially. Until I can leagally do it myself, I have to go and tell the card holder what I want...

I figured as much, but it was worth the thought I guess.
Good luck in your future certification.