Three Stage Cascade

sometimes i wish i lived somewhere, where there was storage room, or a garage, or something where i can stand and build stuff, i have the knowledge, the tolls and equipment to do so. My problem is Where to do it. Here in Strömstad a little city in Sweden, this is a huge problem, there are no garages to rent, or something thats apropriate for this.
I am going to start the building of a direct dye setup on friday, maybe even earlier. If i get the time to do so.

It will most likely be to begin with a singel stage unit.
Testing that out for some time, and then make a cascade out of it.

I wish this day was five years ago, when i lived in a house, where we had a frikin garage.

But i have to admit, being 24 ( going for 25 ) and still living at home with mommy and daddy aint gonna get to fun in the long run...


Although, ( spelling 1 on 1 ? ) the flat that i have now dont come with a garage...



But there will be some building in this little city soon, wery, wery, wery soon.
leets se what this R23 can do for me in a near future.
Not even close to -300f, but hey, atleast, when the :banana::banana::banana::banana: hits the fan, i probably wont exlopde into an orbit around jupiter.
I hope you wont either, but hey, you have a better shoot at it than me.
( Play safe now chilly, you are entering another level of refrigeration technics now days )

Best regards
Ted a.k.a ZejtaN

I would love to go to Jupiter or more to the point Europa and get a few Ice cores and maybe some water from the Ocean there. Explode never...at least I will try not to.

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Originally Posted by chilly1

I would love to go to Jupiter or more to the point Europa and get a few Ice cores and maybe some water from the Ocean there. Explode never...at least I will try not to.

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If you come to europe, make sure to drop by in Sweden, ill buy the coffe, beer i allready have =)
i have got started, soon... on my rig, have a check and make some good coments chilly, your words of wisdom might come in handy.

Ok, I'm only interested in keeping this forum's good safety standards. At least it seems I have succeeded in getting attention to it :)

The thing is that at LN2 temps things ARE starting to behave quite different from what we are used to, and all I want is for you to realize this. There has been so much emphasis on the safety in cascade systems. But nothing near that of LN2, even if that is (at least could be if you are sloppy and not careful and most of all dont know what you are doing) WAY more dangerous! There is just some many thing that could happen to an LN2 system that even the pro's dont know how to handle (the field of cryogenics is way to huge for someone to know it all). That is also why I urged chilly1 to think twice before going ahead even if he is a HVAC engineer (after all your way will be looked upon as the best way, so its best to get that right;) ). I'm an electronics engineer myself, but I'm also a lifelong ( I'm 32 now) hobby inventor and have done my share of crazy things. I have amongst other built water-cooled amplifiers for 10 years now, and at first I was seen as crazy for that, but I don't care :) . If I was to compare myself to someone here it would have to be Dabit (after reading numerous of his posts at phase-change.com with ideas of cascades and all that). If I had more time I would also probably have built a cascade some time ago. I even have the compressors for it (a window AC (3/4hp) and shop freezer (1/2hp) system stil working found on the scrap yard) lying in the back of my yard (plus a few other compressors not in working systems including a few semi hermetic that have been completely disassembled to find out how they work (that was interesting BTW! and part of figuring out how to use it as the basis for a stirling cooler)). :p:

After all, reading this Cryogenic Engineering book the chapter that surprised me the most was the one on safety. Things are REALLY getting hard when trying to reach the temps some of us are trying to here.

And Ted, I live south-west of Oslo in Norway. And I DO have the space and means (and the knowledge too I think...... :) :) :) ) I even have a Bridgeport mill that I'm retrofitting with CNC control (x and y-axis are done, and z is on its way once I get the time........ in a year or two....... or hopefully sooner). I hoping to get a lathe too, and an AC-TIG welder (for aluminum). What I lack now is TIME. Rebuilding my house is taking all my time for the moment.

Oh, and one more thing. In my previous rather long post about efficiency on cascades in this thread....... what I was meaning is that when reaching for cryogenic temperatures what you are calling economizers (as they make the system use less energy for cooling the same load) is no longer just an option (well in theory they still are but.....). If you take a look at the third or forth stage of a cascade and takes a look at what the compressor is really doing you have to take much more care to ensure that the actual work done to the gas is large enough compared to the heat added to the gas by the non ideal compressor.
When any one of you guys did ask Gary for help he demanded a whole list of data from your system. And that is the correct way to do it. But the thing is that in multistage cascade systems there are just so many more data to consider. But that doesn't mean any one of them isn't just as important. In fact they are MORE important. Even things like the efficiency of the heat changers and the efficiency of the compressors are starting to play a larger and larger role the further down in temp you are aiming for. Just for starters take the example of heat added to the last stage by the compressor. If that compressor is working with a low density gas that is poor at heat transportation it will have to work quite hard to remove the necessary heat. That means putting a lot of heat in to the gas stream if you are not careful to use other means to cool the compressor. Oil coolers seem to me to be a possible solution to this problem. That may complicate things, but this is the nature of all this. You simply can not afford for the compressor to be cooled completely by the gas flow anymore. At least not if you don't have an efficient enough HX and pre-cooling. And then it becomes necessary to know the efficiency on the HX' too.......

All this can be avoided by using other methods than phase change. Stirling coolers are my answer, and I'm going to build one when I get the time....... I have the means to build it too (and the knowledge)..... all I need is time....

Oh, and to condense LOX you have to keep absolutely all moisture away! That is actually what you possibly would want to do to your PC-case to, so that is the reason for my warning. A description on how it is done is in the book I’m referring to. And BTW, this is researched by NASA as a way to get the LOX for rocket-fuel in rockets by using LH2 as condensing gas, so you know that too….. this to save the weight of bringing the LOX.

Now I really have to go to bed. Its 2:55 in the morning

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Originally Posted by Zejtan

If you come to europe, make sure to drop by in Sweden, ill buy the coffe, beer i allready have =)
i have got started, soon... on my rig, have a check and make some good coments chilly, your words of wisdom might come in handy.

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Europe is a moon of Jupiter :P

Yes, the behavior of refirigerants of this caliber is not for anyone to play with,
it is to me a little bit scary that there actually are people at home, in there house, "playing" with R1150, in cascade systems riged to there computers,
ok, i have a strong belif in chilly and the other big names here on xs.org that they really know what they are doing ( yes they do know what they are doing, they have allready proved that ).
But if i where to compare with my self and this guys when it comes to computer subcooling, im a retard.
Ok, i have worked in the refrigeration line of work for some years now, and got a pretty good hang of it, ( well, ok, it pays my rent, and a couple of beer's on the friday night )
have made some mach's run R507 and a private little chiller, just for the fun of it,
it isnt untill now, a year after i got the intrest in getting some "extreme" cooling on my computer, i have the knowledge to build it, that i am sure of.
But it will probably take some while before i will build something that goes bellow the -150c, hell, i will be wery happy if i hit -100 before christmas.

And, akb1212, Oslo aint that far away, the coffe is on me the next time you visit Strömstad, because i Know for a fast that you visit it all the time in the hunt for beer, meat, and other food supply's. :D
And get that cnc up and running Fast ! i need you on it, making some stuff for me. =)

Best regards
Ted a.k.a ZejtaN

akb1212
It would be fun with a mail in nor or swe to discuss things, i belive you are sitting on a lot of knowledge that could be a help for me in the cnc world, and probably some other lines of work to, due to the fact that you seem to be an educated man.

zejtan@techsweden.org

"ha de"

when do you think the gas will arrive chilly