Just Chillin Cascade

[{.bLanK} GoD]

My next challenge is under way.
This will be a two stage cascade unit, would be awesome to get a loaded -100°c, but at the least it will be a strong colder than DIce phase cooler.

Stage 1:
Compressor: Matsus h i t a (Panasonic) 8000Btu/hr (1/2 - 3/4hp)
Condenser: Retrofit, flushed, 220hx355wx105d
Fan: 230vac .3A
Receiver: 2.4lt Heldon
Metering device: Danfoss thermal expansion valve (R502) 0X orifice (.5Kw)
Interstage HX: 12 plate brazed plate HX (4Kw)
Accumulator: Custom 2,5/8" x 8"
Safety: Electrical cut off 350psi off 250psi on
Gauges: Permanently mounted high and low side
Refrigerant: R410a or R507

Stage 2:
Compressor: Matsus h i t a (Panasonic) 8000Btu/hr (1/2 - 3/4hp)
Metering device: cap tube (0.031" probably)
Safety:Electrical cut off 350psi off 250psi on, 400psi pressure release valve
Refrigerant: R1150 (Ethylene)
Evap: Kayl evap latest revision
Suction: Yellow jacket SS flexible braided tube (1000psi rated)
Oil separator: Henry helical oil separator with float
Gauges: Permanently mounted high and low side

Parts:
Compressor

Interstage heat exchanger

Oil separator

HP release valve

K type thermocouples and flared cap tubes for the gauges

HP cut out

Gauges

[{.bLanK} GoD]

Been a bit slack on the photo taking till now, but just last night fired up the 1st stage. For no other reason than me loves frost. Temperatures mean nothing at this stage.



This weekend i will insulate, 2nd compressor is due to arrive 15-02-08.

[Fr3akyPete]

Damn! Massive copper-tubes there.
Hope to see some bench-results soon.

[kayl]

very nice work mate, good luck getting the 1150

[n00b 0f l337]

Nice job indeed! Piping looks quite great And finally someone else using quick disconnects! Means I'm not that crazy
Hows that accumulator working? Not trapping oil that you know of? Any problems?

[kayl]

Nice job indeed! Piping looks quite great And finally someone else using quick disconnects! Means I'm not that crazy
Hows that accumulator working? Not trapping oil that you know of? Any problems?

from reading {.bLanK} GoD previous home brewed accumulators in single stage coolers he has a small hole drilled in the return pipe to suck excess oil back to the compressor

[{.bLanK} GoD]

Cheers.
The 1st stage suction shut off valve is 5/8 flare on one end and 5/8 socket on the other end, that's why the suction got stepped up between the HX and the accumulator.
That shut off valve I scored for nothing from the service manager at work, he also gave me the txv and a bunch of orifices in exchange for a bottle of wine. woot.
@NoL - What are you calling a "quick disconnect" ?

And yep, kayl is right, 2mm hole drilled in the return pipe of the accumulator.
Similar to these except this one being 2,5/8" I can get a 180 bend of 3/8" inside which allows me to bring both pipes out the top.

[{.bLanK} GoD]

@NoL - What are you calling a "quick disconnect" ?

After thinking about it, I think you mean the charging hose quick release fittings?
If so you are mistaken, those are just fittings to adapt my R410a 5/16" charging hose to a 1/4" schrader valve.
I have removed the valve itself from the fitting and all schraders as they create a rather large resistance and make vacuuming longer.

[{.bLanK} GoD]

Evap arrived today, and all the mounting hardware.


Getting hold of ethylene here in NZ requires a Hazardous substance, approved handlers certificate.
It involves a day course, I am waiting on a phone call for the date of the next one.
Then it's just a case of signing 2 separate declarations, forking over two hundy and bob's your uncle.
I still wont be legally allowed to transport it, lol, but it has to come from Auckland so I will get it delivered to my door.

[[XC] gomeler]

Then it's just a case of signing 2 separate declarations, forking over two hundy and bob's your uncle.

That's a damn nice evap, Kayl block? Never understood that saying, my British friend says it also to which I typically respond "but I don't have an uncle named Bob!". Can't wait to see your results, good luck with the Ethylene.

[Deanzo]

I've been lucky enough to see the 1st stage running, and even at this early part of the build, I must say it's damn impressive!!

Keep up the great work mate

[{.bLanK} GoD]

That's a damn nice evap, Kayl block?

Yip. As in post #1

Handlers Cert course booked in for the 26th of this month, with a little luck I will have my grubby mitts on a bottle of ethylene in two weeks.
Still waiting for the second compressor

I have edited a schematic to show a basic representation of the cascade I am building.
Referenced from Chilly1.

[{.bLanK} GoD]

Data sheet for the ethylene arrived today. It is actually scary stuff. lol

[n00b 0f l337]

You bet, be 3x your normal safe.
As for other stuffs, shouldnt it be -104C?

[kayl]

You bet, be 3x your normal safe.
As for other stuffs, shouldnt it be -104C?

the ethylene in NZ is colder
I think correct Nol, good luck with the course god

[n00b 0f l337]

Without a doubt Kayl, everythings colder down there. The wool on those 4 billion sheep is not as warm as ours up here

[{.bLanK} GoD]

the ethylene in NZ is colder

Haha I like that "Added to sig".

Bit of an update,
2nd stage compressor has arrived and is bolted down in place.
1st stage gauges, Exhaust fan and cowl, Electrical box and oil separator all in place.

[{.bLanK} GoD]

I am soo pissed off!
I should be sitting my approved handlers cert right now, except the noob at the Trade Academy put me on the wrong dam course. He put me on the Agrichem approved handlers not the flammable gases approved handlers. Roundup just doesn't cut the mustard as an ultra low temp refrigerant.
So now I'm back to no freaking idea when I will get the ethylene. I'm expecting a call with some useful information later today. In the mean time I have got a lot of brazing to do.

[n00b 0f l337]

Wait you sure your not okay? Agrichem I'm guessing is agricultural chemistry, Ethylene is normally used for fruit stuffs

[Moc]

Yep a mixture of ethylene and nitrogen helps bananas to get yellow.

[{.bLanK} GoD]

Yeah i asked the tutor specifically that I need an approved handlers cert for a flammable gas, they don't cover flammable gas.
Yeah agrichem means agricultural chemicals, bulk roundup, tordon etc.
The tutor said she will find the appropriate course/information and ring me at the end of the day.

[n00b 0f l337]

So wait, you sat through this Agrichem class?

[{.bLanK} GoD]

So wait, you sat through this Agrichem class?

Hell no, no point if it is of no use to me.
Since I took a day off work, my time would be better spent working on the 2nd stage.
More pics later today.

[{.bLanK} GoD]

Desuperheater coil, 2nd stage shut off valves, 2nd stage discharge damper coil and expansion tank.


Expansion tank after a clean up.


A lick of paint.


And finally insulated.



Front on view so far.


Side on view.


Still have a lot of piping to do.
The flexible suction line from the evap will be connected to the 5/8" 2nd stage suction shut off valve via a tight 90° bend. Cap tube will be brazed to a short piece of 1/4" connected to the 2nd stage liquid shut off valve.
In theory, this will make tuning the cap length very easy, fast and economical. Should be able to pump the evap down just like a heat pump.
The same idea I have used for the 1st stage either side of the TXV/interstageHX (1st stage evap) so I can change the TXV orifice if need be.
I plan to remote locate all access ports to a central location and label them for ease of access. Just need to find a suitable spot and mount.

[kayl]

good idea {.bLanK} GoD for the fine tuning idea.
Its also good to see ppl using HPCO on both stages
Will you use a thermostat in this cascade to control second stage?
Question, why have you insulated the Expansion tank?.
Your meant to have a long length of capillary line to the expansion tank and braze it in to the 2nd stage suction line near the compressor

I hope they refunded you your money after making you sit the wrong test to get ethylene