brazing the condenser (not done yet- its my first brazing joint)
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brazing the condenser (not done yet- its my first brazing joint)
brazing rods
mapp gas
parts
parts 2
parts 3
the paste for brazing
workplace
well i tried to tell everyone months ago about the solder and low temps.Quote:
Originally posted by berkut
In the past i tested my evaps @ ~30 bar (~420psi) (using solder and didnt leak :D) but it isnt sufficient cause there are temp. fluctuations... like the leak i had- it was perfectly fine during pressure tests to crack when the temp. lowered...
the solder will work if you machine a lip into the block to keep it rigid and stiff.that way the block itself holds its self together and solder just seals the gas in.when the block drops to -40 and below so many times it is trying to flex with the expansion and contraction that takes place over and over again.sooner or later it will leak.
i had blocks leak after a month of running untill i figured out how to stop it.:D
are those brass brazing rods? I hope not those are a real pain to melt.
Nice job Berkut, Can't wait for the final temps. Need a refrigeration job? We have an opening!
i think he lives in poland...Quote:
Originally posted by nyTroX
Nice job Berkut, Can't wait for the final temps. Need a refrigeration job? We have an opening!
too bad, i would take a summer refrigeration job in a heartbeat (if it were close by ;)).
Well I think brass rods are always goldish, but I could be wrong.Quote:
Originally posted by Warlord
are those brass brazing rods? I hope not those are a real pain to melt.
If they are phosphorous brazing rods then you don't need that paste, they are self fluxing.
Also just a tip, I would put a de-superheater (basically a pre-cooler) on the low stage.That way the high stage compressor doesn't have to deal with so much heat from the low stage compressor and less heat from compression.
And always remember to static charge, unless you are making a cascade system with a low pressure refrigerant in low stage, then the de-superheater isn't needed as much and you don't "need" to static charge.
I know, i read all your posts and work on all forums i know you write in.. :DQuote:
well i tried to tell everyone months ago about the solder and low temps.
the solder will work if you machine a lip into the block to keep it rigid and stiff.that way the block itself holds its self together and solder just seals the gas in.when the block drops to -40 and below so many times it is trying to flex with the expansion and contraction that takes place over and over again.sooner or later it will leak.
i had blocks leak after a month of running untill i figured out how to stop it.
Unforutenetly in my future block i dont think ill be able to machine a thing like that... :\
Yes they are :D Ill buy oxygen today and mod my torch :DQuote:
are those brass brazing rods? I hope not those are a real pain to melt.
Thanks for the offer but i do all my stuff my self :DQuote:
Nice job Berkut, Can't wait for the final temps. Need a refrigeration job? We have an opening!
Yes i live in Poland, Warsaw, its written below my nick ;DQuote:
i think he lives in poland...
too bad, i would take a summer refrigeration job in a heartbeat (if it were close by ).
No, they look like copper before brazing and after they are goldishQuote:
Well I think brass rods are always goldish, but I could be wrong.
No they are not self f;uxing, its even on the pics when i show the paste needed for brazing.Quote:
If they are phosphorous brazing rods then you don't need that paste, they are self fluxing.
You mean a normal air cooled condenser or a 2 phase change system before the main condenser ?Quote:
Also just a tip, I would put a de-superheater (basically a pre-cooler) on the low stage.That way the high stage compressor doesn't have to deal with so much heat from the low stage compressor and less heat from compression.
Ok, now some more info on the progress... I coiled the condenser, its 6m in lenght, 10mm OD inner pipe and 22mm outer pipe:
Different angle
Corners
the corners soldered using soft solder
Ok, some info on how to braze...
1. We takse some flux and smear it on the future joint:
Why didnt you go for a co-axial heat exchanger as well? too difficult to make?
Looks good though, didnt realise you were watercooling the top stage...
]JR[
2. We heat it up with a mapp/ propane-oxygene torch and put some solder on it, if its heated up enough ut should fill up the joint very well
Yes, its too much work, this much more simple and needs less resources (the exchanger was made using special soldering paste wich already has solder in it)Quote:
Why didnt you go for a co-axial heat exchanger as well? too difficult to make?
Looks good though, didnt realise you were watercooling the top stage...
In the original version i didnt want to use water for cooling but after carefukll consideration ive decided to make it...
The most important facts:
1. Soundless
2. Can take extreme heatloads
One corner made:
Ok..
Ill have to buy a oxygen tank and ill mod my torch, thats all for now, in 2-3 days ill post some new info...
Ah ok they are brass, I never cared for them.As you can see in your picture it isn't flowing very well, it is clumping.They take alot of heat to flow well, which makes it easy to melt the copper.Also flux in a refrigeration system is no good, which is why I like to stick with phosphorous brazing rods.
Like I said, the de-superheater goes before the low stage condenser to cool hot gas entering the heat exchanger.
One more thing, that condenser you had could handle the heatload easy.Even on low fan speeds.If you fixed it of course.
Silver solder or sil-phos. Anything else just doesn't cut it. And silver solder flux works great for both.
I don't see any brass in the pictures. Those are all copper fittings.