Mine first "serious" cascade, 2 x ROTARY ..-96*C@215W,

Hi

A bit long time ago I've started building mine first seroius cascade, using 2 rotary
compressors (the first ever I've build in summer 05' but it had never worked properly
because of too weak 1st stage compressor

) . I had planned to make cased casade
(I had one cuted wooden base left) and with quite big SLHX before interstage HX. First I had
planned to go with CPEV on 1st stage and captube on second, later I swap it to captube on
both stages, because CPEV wasn't worked good as a 1st stage expansion valve

. Work
started at Septemer, than first test and after it I wasn't really happy with it (some tests
on LanParty and it made around -95*c on Conroe E6700@4.5 Ghz) . Then bit long break because
of having absolutely no time for it, and after Xmas I've finished it (change expansion valve
to cascade, throwing away one gauge, mount cut-off repaint of case, puting one UV
coldcathode inside)

.

Specs :

Compressors: Sanyo remark C-1RN57H5A on 1st stage, LG QB164PAB on 2nd stage
Evap: 50 mm tall spiral evaporator by piotres with CNC made black enclosure
XV: Captubes on both stages, 0.8 mm
Condenser: 1.5 kW, 2 row, alu-cu, cooled by orginal 230 V fan, splited for 2 loops (one
small loop for 2nd stage desuperheater)
HXes : 15/8 mm 4.5 m long Interstage HX + 15/8 mm 2.5 m long SLHX
Oilseparator : Temprite 340 with Castel handvalve (on the front panel)
Refrigerants : R507/R1150
Case : Chipboard case, dimensions 64x54x42 cm, painted black
Safety : Cut-off with autoreset, set for 25 bara
Others: 2nd stage discharge gauge, coldcathode UV, LCD HX outlet temperature probe, small
expansion tank, Delta 120 mm fan in side wall to cool two rotaries

CPEV valve which was mounted only for short time as a 1st stage XV

Evap is bigger than that which I usually use, suction line is braided, around 140 cm long (stainless mesh).

That green probe make around 5-10*C fail around -100*c range (show too high temps), so later I've swap it for good one (yellow

) .

First time I've used Danfoss EVR3 solenoid as a oil back valve - but it has a leak, so later I've changed it for Castel handvalve mounted on front panel of case.

First run with Ethylene . That probe showed bad temps as I've wrote above

Short test on LanParty in Warsaw, IIRC that was 20.09.2006. ;-). On E6700 set to around 4500 Mhz it's has made -95*c measured but bad probe ...but I wasn't happy with it, discharge pressures are bit high on both stages, CPEV on 1st stage was a bad idea .

Now quite long break ...no works on cascade ...and

After changing XV on 1st stage for captube, mounting cut-off, and removing 2nd stage low side gauge (it was damaged) I put some co2 inside 2nd stage ;-) ...so I'm now in -100*C @Co2 club hehe

And above -120*C overall (R1150)

Finished, only case left

Delta 120mm fan and CCFL UV .

After screwing case I decided to change outside color of cascade for classic black ..ahh not so classic, because it's paint used for bumpers in cars, it has specifical structure (it is not smooth)

Temperature on 215W dummyload = -96*C

On 115W = -102.5*C

Evaporator unloaded is around -112*C with final charge.

Interstage HX outlet with no load .

Cascade is for sale, shoot me PM if You're interested :-) .

Regards
Peter