r420 will do the job but from what i have heard berkut say r22 is the best and r290 is supposed to be pretty good too.
ps: r290 = propane
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r420 will do the job but from what i have heard berkut say r22 is the best and r290 is supposed to be pretty good too.
ps: r290 = propane
what is r420? or do u mean 402a?Quote:
Originally Posted by f00t
Im wondering if 402a would work since it boils colder than R22 does so it would be less likely to effect the temps the co2 reaches.
Also, oil must be cooled, probably that's why a traveling through whole unit is needed, it cools at evaporator and suction
Don't forget that the gas return is what really cools the compressor. Also having oil in the evap reduces cooling efficiency because its coating the walls of the copper tubing. Like i say im gonna cut open my old rotary vacuum pump this evening and see if its self-lubricating or not i think that will help resolve this issue. On another note how would u build an oil separator?Quote:
Originally Posted by Tonic
lol yeah i ment r402a. not enough sleep
I cut open the rotary compressor and there is a hole in the middle of the shaft possibily for the oil but ill have to do further cutting to get a better look at the bottom. Heres some pics of it.
UPDATE!!
I drilled some holes and mounted the second compressor in place, it just fits :p:. I also brazed a desuperheater to the discharge of the compressor and ran it around so its mounted behind the fan thats on the condensor for stage one so an extra fan is not needed here :cool:.
Can only upload 5 pics at once :mad:
I pumped some R11 through the condensor for the 2nd stage to remove the moisture in it. Thats R11 in the icecream container in liquid form cool huh?
really nice :banana: ! I was wondering why is your hx made that way? I mean why you didn't put simple pipe insulation? Hurry I want to see the temps so we can compare each others system :D (I made a cascade and auto-cascade yesterday but I can't tune it yet because I have no probe that goes lower than -55c) Good luck on that "thing" !
The cascade is really coming together nicly, should see some noce temps with that.
Quote:
Originally Posted by _HL4E_HalfLife_
they should make fine compressors, unless been used too much.
they look like old r22 ones (what refrigerant are they?)
more than likly mineral oil i would say. just drop the oil and replace it with new stuff, also give ya an idea of what work it done.
those 2 compressors are capable of -100c with a co2/r290 cascade. ;)
as for oil separator i would just use one just in case to be safe.
the r290 will carry some of the oil to the separator and then back to the compressor when return valve opened. and ya dont want oil in capillary line to add to blocks second stage.
i think that r402 does actually consist of some r290 r22 and something else.Quote:
Originally Posted by _HL4E_HalfLife_
Google search on it and find composition.
Just try it and see who ya go
its expensive stuff though, $38kg compared to r507 $18 i just need a frigin license, unfair.
r22 / r125 / r290 ratio : 38 / 60 / 2 . I think r125 is mainly a firefighting agent.
Man you guys post quick lol and yes they are R22 compressors im not sure about the oil in them heres a pic of them the clear oil (one on the left) is the oil that came out of the rotary i got on 1st stage. So what the heck is it? AB? Ester? Synthetic?
my bottle of mineral oil have the same oil color as the one on the left if that help you.
btw imo the oil color you have mean your compressor is in perfect condition! I mean not even a bit dark! that's great!
O yea i almost forget this clear oil seems to carbonated as well it was making bubbles for quite some time after i removed it from the compressor. I've never seen mineral oil do that before so im not so sure that it is mineral oil. Any idea what color AB,Ester, and Synthetic oils are?Quote:
Originally Posted by Cr@sh_D1n3r
:D :D :DQuote:
Originally Posted by Cr@sh_D1n3r
I once removed the oil from a rotary compressor with mineral oil in it and it did it :) lol we are flooding the forum :P do you have msn ? would be cool to have each other address :)
This isn't flooding, were providing useful information for rookies out there.Quote:
Originally Posted by Cr@sh_D1n3r
Ps.yes i do have msn.
On a side note for those of you that are wondering what im using for a torch...
Quote:
Originally Posted by _HL4E_HalfLife_
Indeed, it's nice to read your coversion
Acetylene/Air torch, if you can, shot photos of torch at action :)
LOL sure np next time i braze something ill take a pic heh.Quote:
Originally Posted by Tonic
Again about the type of oil i should use i didn't really get a direct answer on this so since some 402a is gonnna be added anyway which has R22 and R290 in it i decided to just leave the MO in the compressor since MO works best with R22/R290 this shouldn't be a problem should it?
Ps. where would i find copper/steel wool?
You can buy those wools in markets/supermarkets/hipermarkets. They're used to wash the dishes :D
About oil, sorry, at the moment I can't understand, I'm to sleepy.. :PMaybe tomorrow I'll read a few late
pages and try to answer
Ahhh i was wondering about those dish washing wools i just wasn't sure if it was the same thing as what you guys were using. So what do you guys use to keep the wool in place in the oil separator?Quote:
Originally Posted by Tonic
Heres that pic u requested tonic. :D :woot:
Just a thought..is there any reason not to use manifold gauge hoses to connect up the evap? I know they would have to be tightened alot to prevent leaks but they would be perfect since there designed for high pressure.
Yes there's simple one : it's not made for such low temperature. The hose will freeze up and will get incredibly hard to bend so all vibration will go to the cpu :P
deigned for high pressure but not cold. if your gonna be at -70 some with a rubber hose the slightest abrupt bend could crack it