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Re: Cascade Refrigeration System
Yep Peter,
die zie je nooit meer ....terug.:p
Ice
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Re: Cascade Refrigeration System
its pity, because its a nice tread. i love to read about other opinions, and done some calculations of mi one.
i can not build mi outcomes because the lack of money and time.
O, and extremesystems is wonderfull to browse around to.
hope we get more of this cind to follow.
Ice
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Re: Cascade Refrigeration System
Ken
good afternoon
i am intrested in the low tempture cascading system that i found on this site.
you refer to a consulant who is knowable. can you forward how to contact this person.
thanks in advance
chuckw
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Re: Cascade Refrigeration System
Chcukw, send me a PM and I can send you the name of a good consultant.
Ken
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Re: Cascade Refrigeration System
Quote:
Originally Posted by
Vincent Yu
Thank everyone for the valuable suggestions. Currently our company builds 2-stage cascade systems. Normally they are used in vacuum chamber and testing chamber. Two ¼ HP compressors are used. The system can reach -100 degree Celsius. We do have some experience to design and manufacture two-stage cascade systems.
Recently, a customer has an application which needs the temperature goes down to -130 degree Celsius. We plan to develop a 3-stage system based on our current 2-stage systems. Following is an outline of my design. Please give me your opinions:
Three ¼ HP compressors are used. For two stage systems, it is a good choice to use 2 compressors having the same power. I am not sure if this principle still works for three stage systems.
First Stage: condensing temperature: 35C; evaporating temperature: -30C. Refrigerant: R404A or ISCEON89. A fined tube air cooled condenser is used.
Second Stage: condensing temperature: -25C; evaporating temperature: -75C. Refrigerant: R23 or (R508 + R14).
Third Stage: condensing temperature: -70C; evaporating temperature: -140C. Refrigerant: R14.
By my rough calculation, if the refrigerants are selected as above, the condensing and evaporating temperatures in each stage should be the values I give. But I am not sure if the system is optimal in these conditions. It is very difficult to get the optimal solution just by calculation. I will adjust the system based on test result.
Plate heat exchangers (WTT) are used between first and second stage, and second and third stage. Five degree temperature difference is enough for efficient heat transfer.
The metering device in first stage is a thermal expansion valve. Capillary tubes are used in second and third stages.
Cylinders are used as fade-out drums in second and third stages. They are place in the low side between the evaporator and the compressor. The size of the tank will be determined by experiments. There is no harm that the fade-out drum is a little bit oversize. Is it correct?
Coalescent oil separators (Temprite) are used in second and third stages for oil separation.
The principle of cascade system is very simple. But to select parts and build it is very challenge. I start to test the performance of the first and second stages, and hope it can provide about 300 ~ 350 watts cooling capacity at -80C for the third stage.
Now I still have trouble to find a suitable compressor for the third stage. And I also need to confirm that R14 is the best choice for the third stage. Any information and suggestions about the compressor and the refrigerant for the third stage are welcome.
Ken, Could you give me more information about the consultant you talked about? If he is really very professional in cascade system design, and if we really have trouble to develop it by ourselves, maybe my boss is willing to pay him for his help.
Thanks again. I am willing to share all the information with you, and will report you guys my work on this project regularly.
Vincent
good morning
i have been enjoying this site about the low tempture cascading systems.
have you had any sucess with your efforts.
i would appreciate any info that you are able to share.
it sound like your idea has some merit.
chuck Wiedemann
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Re: Cascade Refrigeration System
Quote:
Originally Posted by
TXiceman
Chcukw, send me a PM and I can send you the name of a good consultant.
Ken
Ken
good morning
my contact info is
Cwiedemann@space.nrl.navy.mil
202-404-2592
thanks in advance
c
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Re: Cascade Refrigeration System
Hi.Everybody I had used a cascade system at -80 c with Bock compressor . Who have been use bock.pleses advise.because I not sure the HA compressor run with R 23 can use longtime.
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Re: Cascade Refrigeration System
Hi everyone,
I have a graudation project that is a blood storage. The blood storages are cascade system, thay works about -40 degree celcius.
But I dont know that How I can design it after calculating cooling load.
Please help me about design a two satge cascade refrigerator. where I will start?
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Re: Cascade Refrigeration System
Depending on the capacity you need at -40 you may not need a cascade a compound single stage could be used.
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Re: Cascade Refrigeration System
For blood storage cascde systems are used. I need design procedure of cascade system. You know that is is a graduation project so that it has a small capacity. It may be for 10 lt blood.
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Re: Cascade Refrigeration System
are there anyone for help me? :)
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Re: Cascade Refrigeration System
Sawasuar, not to be rude, but I thought this was your design project. People would be willing to help by answering questions which show you had put some thought into the design.
Several of us have ideas on how to approach this project, but we are not the ones being graded.
Best of luck,
Ken
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Re: Cascade Refrigeration System
Hi
I am trying to design a R23-R22 cascade system. I have decided to have a 5HP scroll Comp for low cycle and 10HP comp for high cycle and a Plate cascade heat exchanger and air cooled condensor. My cooling load is at most 5KW and operating temperatures are -70C for evaporating and 35C for condensing.
I have to have a tight temperature control +/-1C within the range.
I wanted to know if it is ok?!
I don`t have enough catalogues for selecting my compressor, Plate HE, TEV, Solenoid valves,...
whould you please help me?
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Re: Cascade Refrigeration System
Hi
I am trying to design a R23-R22 cascade system. I have decided to have a 6HP scroll Comp for low cycle and 10HP scroll comp for high cycle and a Plate cascade heat exchanger and air cooled condensor. My cooling load is at most 5KW and operating temperatures are -70C for evaporating and 35C for condensing.
I have to have a tight temperature control +/-1C.
I wanted to know if it is ok?!
I don`t have enough catalogues for selecting my compressor, Plate HE, TEV, Solenoid valves,...
whould you please help me?
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Re: Cascade Refrigeration System
What issues you have with ha series ? What problems & reservatiions with ha series ?
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Re: Cascade Refrigeration System
For 20 Watt capacity(-140C), why not think about the pulse tube or Striling refrigerator? maybe it should be a cheaper and more convienent option for you.
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http://www.liangdianup.com/tobacciana_z.htm
I am thinking about buying some wholesale water pipes from this company in China
but I am not sure if they are legal to bring in to the states? What are the laws on water pipes, bongs, and pipes?
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Re: Cascade Refrigeration System
Quote:
Originally Posted by
ksvinod
i from electrolux , i would like to hnad over all ultracold medical cascade refirgeration system data
regards
vinod,india
plz help us we r making -90 C, cascade system of 400 litrs chest type, using tecumseh comp. , please advice condenser and evoperatr design, and the length of tube in tube system.
bharat
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Re: Cascade Refrigeration System
I built and was using (-190C)-(-196C )cryo chamber (metal treatment, cooling engine blocks 400kg a time)), using joule thompson effect (about 200watts,)
low capital cost, efficiency about 5%.
If you have a two stage system already your just about there.
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Re: Cascade Refrigeration System
Hi Vincent,
we have some experience with 3 stage cascade system with -130C evaporating temp. Talk to your boss, we can certainly help you!
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Re: Cascade Refrigeration System
You don't need three compressors, Sanyo does a -140 and a -150 with just one compressor. The oil is POE and Pentane mix at that temp.
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Re: Cascade Refrigeration System
Quote:
Originally Posted by
ksvinod
i from electrolux , i would like to hnad over all ultracold medical cascade refirgeration system data
regards
vinod,india
vinod plz help,we want design for -80 c,280 ltr cascade system.
Bharat, 09415157857
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Re: Cascade Refrigeration System
Anybody interested in low temperature Autocascade systems may find this article interesting. The author is Michael St Pierre, he worked many years ago with Dale Missimer, the inventor of Polycold cryocoolers. It's enjoyable reading if you're into these things!
WorldWideWeb.xtremesystems.org/forums/showthread.php?t=144007
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Re: Cascade Refrigeration System
Quote:
Originally Posted by
bharat
vinod plz help,we want design for -80 c,280 ltr cascade system.
Bharat, 09415157857
is there anyone who can help me design a cascade system -80 C, 300 litrs, .
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Re: Cascade Refrigeration System
Greetings Mr. Vu,
20 Watts cooling @ -140 C using 750VA
See vvww.arscryo.com/MR.htm
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Re: Cascade Refrigeration System
Sorry if that link wont work, just Google "ORCA MIXED REFRIGERANT COOLER"
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Re: Cascade Refrigeration System
Hi Friends,
I am Vikas. I did Charging of -86 deg C Freezer as per brochure of Manufacturer. First chargedone unknown refrigerant thru liquid line then Second refrigerant charged thru suction also inlquid state slowly as per instructions. Refrigerants were supplied by manufacturer as A and B. I got temp - 80 deg C however i was supposed to get suction of around 7 PSIG and disharge of 280 but got suction 40 PSIG and discharge 200 PSIG. the Freezer works on Autocascade and 2 nos of 3/4 HP Compressors are in parallel.
can anyone throw light on why I got 40 PSIG at suction?
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Re: Cascade Refrigeration System
IS this a Polycold machine?
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Re: Cascade Refrigeration System
Quote:
Originally Posted by
Vincent Yu
Currently our company builds 2-stage cascade systems. Normally they are used in vacuum chamber and testing chamber. Two ¼ HP compressors are used. The system can reach -100 degree Celsius. We do have some experience to design and manufacture two-stage cascade systems.
May I ask at what temp this system is rated for?
Could your unit sustain a 200-250 Watt load on an evaporator that is designed and used in cooling CPU's in computers?
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Re: Cascade Refrigeration System
The reason you still have problem at lowest stage with the oil is because of the flock point. Flock point is when the waxes or other components of the oil turn to solid or less viscous substance. Not allowing the refrigerant to flow freely causing it to meter where ever the oil freezes at.
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Re: Cascade Refrigeration System
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Re: Cascade Refrigeration System
Hello vikas,
You made [-140°c unit?
- 9825044534
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Re: Cascade Refrigeration System
Mr bharat
you made[-140°c unit]?
- 9825044534