Commercial -150C

[ultralo1]

Here are some pics of a commercial -150C. This is a 7 cubic foot chest used for the long term preservation of tissue and cellular samples. It is also a first for me. The gas blend is propriatary so the company only sells the premixed blend at $2500 per charge. They gaurd the exact blend very well and dont ilke to discuss it at all with us non company employee types. With a little guidance from Mytech, I have developed a blend that works in these units.

Now onto the pics.

The unit


The prize


Side view showing Buffer tanks, expansion tank, LPCI, Pressure dump control and solenoid, Comp, Condensor.


Top controller is LPCI, The bottom is the dump controller


Expansion and buffer tanks


Close up of comp compartment


Comp model tag


Another comp area


The oil seperators in parallel. They found that in series did not seperate as well. Parallel allows the flow rate to decrease enough to seperate very efficently.


The design temp is for -150C max. I am running -153C max. The high side is 260psi and the low is 28psi. This system will be put into service as a rental unit for my customers.

[DonNiger]

Just put your PC into the cabinet ....

[sdumper]

Very nice work!!!

[Patrickclouds]

yeah great unit.

gases are? argon, r50, r14, r23, r404, r134a?

Just put your PC into the cabinet ....

that won´t hold the load of a computer



ah here is the datasheet of such a cryogenic freezer i have found on my computer
http://members.extremecooling.de/pat...n.%20Daten.pdf

[ultralo1]

gases are? argon, r50, r14, r23, r404, r134a?

R600, R507, R508b, R14, argon

ah here is the datasheet of such a cryogenic freezer i have found on my computer
http://members.extremecooling.de/pat...n.%20Daten.pdf

Same unit

[n00b 0f l337]

Looks good, assuming the huge tank is the expansion tank.
4 ton scroll as well? Looks like the one I just bought off the bay'. (Same series but 1.75 Ton)
Wish condensers like that were easy to get as well!
Any pics of the heat exchanger stack or was it all foamed?

And of course, you didn't feel the r600 would allow sufficienct oil removal? That's a hell of a lot of oil separation.

[ruffus]

i have a compressor just like that as well. this is a autocascade right if so then i now know what i will be doing with my scroll compressors as i do have a couple of them and we not going to do anything with them as i was told that they were no good for what we do with them as they don't like LBP's something about oil problems just can't remember who told me this

[n00b 0f l337]

They're more stringent to there ratings. The LBP ones are good for LBP and not much else, and same for MBP and HBP.
The hard part though is definitly a big enough condenser, luckily the high boiling point refrigerant or auxillary condenser helps dump an incredible amount of heat (like how a 2nd stage in a cascade needs only a small desuperheater), and allows you to get away with alot less.

Something tells me though that I'll get a 5" x 12" plate heat exchanger or similar of massiveness

[George_o/c]

Holy , that looks badass !

[Patrickclouds]

is it an autocascade? with copperpipe heat exchangers? did you use phaseseps to seperate gas from liquid?

or works it like a mixed gas joule thomsen circuitwithout phaseseps?

[SAE]

From that datasheet: Autocascade, compressor Copeland 3.5HP

[sdumper]

Hey ultra can you show some picts of the phase separator?

[HDCHOPPER]

Jeezzz O petes thats beautiful

thanks for the gas mixture !

[ultralo1]

And of course, you didn't feel the r600 would allow sufficienct oil removal? That's a hell of a lot of oil separation

The 600 is used as a refrigerant in this case. there is about 20 Oz in there. The total factory charge weight is 90 ounces of the mix.

is it an autocascade? with copperpipe heat exchangers? did you use phaseseps to seperate gas from liquid?

It is an Autocascade. The heat exchanger is basically a shell and tube like Mytech did in his window unit conversion. There are phase seps in it.

Hey ultra can you show some picts of the phase separator?

I wish I could. I have only seen the stack once and that was at the manufacturers school, no pics allowed. From memory they are just like what you guys build. The big ones are made from piping and caps, the inlet comes in from the side at an angle to get the incomeing mix to swirl and help seperate, the top has some copper wool in it and the bottom feeds out to a cap tube. They final phase sep is nothing more than a 5/16 tee.

[quintus]

Got something similar at my university, maybe a double autocascade, there were 2 compressors if i remember well and a lot of freons.
Ultralo1 when i will have pics of it can i post them here?
regards,
q

[ultralo1]

Sanyo makes a -150 semi autocascade. They have two comps. The first stage is a hermetic the runs a high boilin point refrigerant. The second stage is the auto cascade section the runs the mix of low bioling point refrgerants. Maybe thats what you have seen.

[quintus]

You might be right, from what i can remember there where 2 or 3 freons per each stage. Will keep you up to date

[n00b 0f l337]

How'd you "harvest" the r600?
I can't seem to find more then lighter and stove bottles, but nothing big, and nothing with an access I can really get into. I've been using a puncture tap and I don't like it.

[ultralo1]

How'd you "harvest" the r600?
I can't seem to find more then lighter and stove bottles, but nothing big, and nothing with an access I can really get into. I've been using a puncture tap and I don't like it.

I had to buy a 30 pound cylinder for another project. I had to adapt a fitting for it to use my gauges on. I think I bought the 600 from National welders.

[wdrzal]

Hey congrats to you Ultralo1,& Mytech not only for the the temps but more impressive is 28 psig. Compressors won't survive @ 26hg vacuum long but @ 28 psig they might.

Ultralo1 at least you didn't use -150c and LONG term preservation in the same sentence. kidding

I would put those in different paragraphs in the warranty. not kidding

I think a scroll is a good choice for compressor type, especially since they fixed the problems with the early model scrolls.

[n00b 0f l337]

Airgas. Cool.
Will give them a bite. I hate tapping these small suckers.

[n00b 0f l337]

Last q, buffer tank was the small one or the hugeee one?

[tiborrr]

Looking great. My next adventure will certainly be 2-stage auto-cascade, aiming at -100°C idle, can't wait to start it!

[mytekcontrols]

Hey Britt glad to see that you got it working ok

With a little guidance from Mytek, I have developed a blend that works in these units.

Actually you did all the heavy lifting so to speak, and it looks like you can now enjoy the rewards of your hard labor (like saving $2,500 a pop, and now having your own charge to sell for these units).

Very nice looking unit. And it looks like your compressor suction cooling is doing very well. I would imagine that the compressor is quite comfortable, and as Walt pointed out, a 28 psi suction (what was the discharge?) should increase the longevity considerably over a standard cascade.

Edit: Opps just saw that the discharge pressure was 260 psi. A little over 6 to 1 compressor ratio. That compressor is going to live a good long life.

[K404]

If this is for sample storage, is it safe to say the unit is tuned for very low heatloads?

Not take away from the achievement of offering -150 on demand