captaincascade's help+stuff=thread

[baker18]

Originally posted by captaincascade
you think i could see some designs you have,,, just so i got an idea of what im workin with?.

Bowman posted a picture of my block.

http://www.xtremesystems.org/forums/...&pagenumber=18

Post #438

baker18

[captaincascade]

christ baker, thats about as hardcore as i could have imagined.... im in....

i only wanted to use 1 phase seporato.. this being more of a expierament... ill get started on the standard cascade thiks weekend.

[captaincascade]

oh and a big thanks to enigma for puttin those pics up. and the drawing he made. .....good man


oh and if you guys wanna know how i found this place... anigma, pointed me here.

[captaincascade]

lol looks like i might have to break my own rule..... i dont have 2 scrap compressors that are the same kind, lying around. so i may have to use 2 different ones. eh well its a small load anyway. whats the btu output of a normal processer

[captaincascade]

heres a link to sporlan goes into alot of stuff i think you might find it useful

http://www.acalny.com/201ME.pdf

[captaincascade]

1st stage is complete ill post some pics when anigma wakes up.
my interstage only got to -35c., but i think thatll be fine

[TheDude]

Cool! Can't wait to see the pics!

[captaincascade]

http://www.subz3ro.net/1st%20stage%20001.jpg



ok theres the first stage. i know how everyone likes to see ice so they know its runnin so this pic is taken shortly after start up. the condenser is a little over size for no load so i had to pulse my big as fan to maintain propper head pressure. i used 404a and cap tube. you can see i just wired the start components right there next to it. i ended up puttin on a txv by the end of the night.

Im not gunna try and be all cool. this is a pain in the but. im not used to improvising from scratch. im only alowed to use old parts so its kinda restrictive. christ it took me an hour to find that fan and mount it. im now whining and thats ok with me i thought i could do this in a night boy was i wrong. thisll take at least 3 nights.

http://www.subz3ro.net/1st%20stage%20002.jpg




and heres a pic of my thermometer for some reason. i didnt catch it at -35. i think my senser placeing is kinda screwed up its right there on the inlet of interstage. im gunna soder on a little port for my sensor.

i dont have a match for the compressor so i may have to compremise.

ps...by nights i mean 1200am to sunrise.

[bowman1964]

good luck.

it never is as easy as it seams.expecially when you need to do it in a hurry,never fails ....small problems will set you back.

keep at it,do it to relax, not because it is a job..or it will burn you out...

good luck again Capt

[baker18]

Just got back from CaptainCascade's hideout.

Here is a picture of CaptainCascade's cooler with a baker block......

[baker18]

another picture.

[baker18]

CaptainCascade's playground.

[baker18]

Finally......

-80C freezer....................

[TheDude]

AWESOME!

[Gary Lloyd]

On the autocascade:



It seems to me that if the condenser had parallel runs (as opposed to serpentine) with headers at each end, the hot gas could enter the middle of the header on one end, and exit top and bottom of the header on the other end. This would combine the condenser and phase separator.

Assuming the condenser is like the drawing, the non-condensing (high pressure) refrigerant will tend to collect in the top of the serpentine condenser, while the condensing (low pressure) refrigerant will exit the bottom of the condenser in liquid form. At the very least, this could cause the operation to be very erratic.

[herefishy]

Hi Cappy! :-)

This is the first time I have browsed your entire thread. I noticed something in one of your pics. Your TEV cover cap on your expansion valve is missing. the TEV should be operated with the cap on the valve. Not to get off on the wrong foot, but you will be interested in the following phenomenon:

Try this sometime. check your superheat (in whatever manner you do - multiple temperature, or temperature/pressure) and remove the cap on the TEV. See what happens. Then put the cap back on and see what happens. The cap serves NOT to keep the valve from leaking (the adjustment stem packing serves that job), but to insulate the adjustment stem from the ambient temperature [also] (if you wish to speculate that it is a secondary leak protection). The stem will conduct the ambient heat into the valve body and affect your superheat setting.

After making a TEV adjustment, you should always re-install the cap (even just finger tight will suffice between adjustments) and allow the valve to "settle in", before checking and making any other adjustments. I just thought that you would find that interesting. If you try what I say, your lightbulb will come on.

Anyway, I have a few questions for you. One will not find compressors rated for, say R-170 @ -80F. What is the criteria of compressor selection for these cryogenic refrigerants and applications?

I have (re)charged the second stage of a cascade, only once. It was refrigerant grade ethane, I believe. It was contained in a silver high pressure gas cylinder (like an oxygen bottle, ya' know) with a blue cap. Could you possibly confirm the refrigerant I was using (it was 8 years ago). the charging was accomplished by hooking up the bottle, and letting the system stand for 12hrs @ 75F room temperature at a particular pressure (75psi, or something like that).

If I build a cascade, I would like to utilize R-404A first stage, and ethane for the second stage. I don't suppose that R-23, 508B, or any of the refrigerants that you have posted the properties of would have lower stauration temperatures than the ethane, if I recall my browsing of P/T charts properly.

I am of the opinion that a couple of my tecumseh TPA1390 compressors, back to back, first stage @ 0F to -10F, R-134A @ 950btuh, cooling the second stage, ethane @ ??F (don't have P/T chart, now) anticpated 400btuh (150watt), may serve the task. what do ya' think?

I might point out, in regard to the pump-down type systems, and the application of receivers, that these configurations are not utilized with cap-tube applications. Cap tube systems are "critically charged". I noticed that you are using TEV's, as such receivers and pump-down are good practice (you must use a receiver with a TEV for proper operation).

Anyway, your insight in regard to compressor selection and ethane refrigerant thingie would be greatly appreciated.

see ya'

[captaincascade]

loyd


if i run my outlet off the top of the condenser. Am i looking a a potential place for oil to sit? on the bottom part of the condenser?

herefishy

yer dam right about the txv. didnt even think about it. good lookin out man thanks. please if any of you see something wrong , let me know. im pretty dam far from perfect.

we retrofit 95 in 170 systems without any problems

170 is grey/silver bottle, yeah id say thats what ya got.

i think 170 is alot like 503.

its kind of a rollin of the dice, to pick a suitable compressor. if you look on the wich compressor for cascade systems thread, i posted some model #s

id say go for it, just make sure your 1st stage works right. before turning on your second

[captaincascade]

try to keep in mind i made this cascade system in less than 24 hours. the cap tube baker has is to small and to long. but the block kicked but. the coldest we got it was -55. ill shorten the cap and we'll get -80 no prob



im not even going to tell you my 2nd stage head pressure.

[herefishy]

Originally posted by captaincascade
its kind of a rollin of the dice, to pick a suitable compressor. if you look on the wich compressor for cascade systems thread, i posted some model #s

id say go for it, just make sure your 1st stage works right. before turning on your second

10-04 dude,

I think that I will employ either a thermostat on the interstage heat exchanger, in order to control the second stage. either that, or a high-side pressure control on the second stage. I think the second-stage high-side pressure would be best, I'm thinking as I type. Any thoughts?

see ya'

[captaincascade]

http://www.xtremesystems.org/cc/cas7.jpg

i made a ladder diagram of simple wiring

see if it makes sense

[captaincascade]

you can even use a low side pressure cut in on first stage to turn on second stage.

[Gary Lloyd]

if i run my outlet off the top of the condenser. Am i looking a a potential place for oil to sit? on the bottom part of the condenser?

Read my post again. Outlets top AND bottom.

[captaincascade]

ohhhhhhhhhhhhhhhhhhhhhhhh it is a serpentine condenser.....are you asking if its a paralel flow condenser?

so you guys keep up with what we're talking about.

http://www.narsa.org/acj/archive/acj...AC%20focus.pdf


idea....
what kind of reluts do you think id get, say,... if i were to use a paralell flow condenser, and i tried to use it as the phase seporator and condenser,,, ataching the inlet in the middle or top lets say and pipin the hot gas off the top of the thing and pipin the liquid from the bottom

do you think i could use it as a phase sep and condenser?
it doesnt sound right to me. hmmmmmmmm....loyd.

[Gary Lloyd]

Actually, I think the condenser and separator have to be combined, because the condensing causes the separation.

[captaincascade]

this is the same design condenser as on the auto cascades i work on. but i see what you mean.