I'm a little confused, I read some of your posts back in the archives but couldn't understand in which way HC's blend would behave, is it going to lower the evap temp @ given pressure or just giving a huge glide, like R407C does ... Not very well with all that chemical stuff :p
From the old info and from Before's writings on it, you get something between a glided two refrigerant system, and the propertys of just there averages as "one" refrigerant. Strange behavior, but makes mixing a bit easier.
Originally Posted by Movieman
First of all : you have to clean your inbox messages, I can't answer you until you do that
Interesting... So mixing some methane with the existing shot of R1150 in the third stage could bring down the boiling point @ given pressure ? I don't have so much data about it, and Before' settings are pretty far away from my three-stager anyway. He doesn't answer to my PM's though ( he's french too ) I wanted to meet him to buy his remaining R14
I'm seriously considering that way, R14 is freaking hard to get, regardless to price :o
It'd be fun to try R404/R23/R1150-R50 pattern, biggest concern is to not overload second stage, as there isn't a large amount of raw power ( SC21G piston type ), I have to think about all that stuff. What will you do about it ?
Last edited by Sk_rmouche; 06-18-2012 at 06:56 AM.
This might seem odd, but I can't find the damn delete button on old messages.
When you try r404/r23/r1150 you'll notice you'll have almost no condensing pressure on high side in third stage, at that point you can shut her down, let it warm up (never charge a cascade cold!) then add a bit of r50, and boot and see changes. It's going to be very empirical, but either it will condense, end up in solution, or itll just give you a higher pressure on the high side to increase the mass flow via the differential.
To delete some messages, you just tick the cross ( is that what we say in english ? :p ), then move and click to the "selected messages" button, and make your choice !
Well okay, I was expecting that answer, begin with pure ethylene, then fill-in slowly some methane after it warmed up. I plan to braze a dead volume to withstand the extra pressure, didn't put that on second stage and got 15-20 bars pretty darn quickly, even more with hot compressor after hours of run. Still brainstorming about rotary or piston type to that third stage? I don't have that much space in the "box", rotary should fit well, but may overheat quickly with low BP and no floodback, rotary @ first stage is only @ moderate T° because it's continuously flooded
So by your opinion I should try mixing some HC's to get a colder boiling point, I'll follow that advice if I don't get my R14
Last edited by Sk_rmouche; 06-18-2012 at 12:20 PM.
Yeah was acting funny but okay now. All good and PM able.
Naw less so about the flooding and more so about the heat of compression of the gas that's in it. Even if you flood back a rotary running R14, that sucker will run hot. A few packets on cryogenic HVAC all recommended specialized compressors with an active oil cooler, or to place a desuperheater on the post oil separator line and overfill the oil separator by an 15-20%. Refrigerant-engineers forum online has alot of info on R14 and such.
I read some topics of refrigeration-engineer, you just gave me an excellent forum indeed, will try to post some stuff there
Rotary isn't the best compressor for that purpose, piston type would be just fine, I just need to fin the good one ( maybe GS26CLX, it's a good one with nice efficiency @ low pressure ). Quiet surprised by my first stage rotary though, discharge T°c is amazingly low ( around 60°C max ), and the shell itself isn't that much higher, thanks to constant floodback and 1.5+ bar back pressure.
Last edited by Sk_rmouche; 06-21-2012 at 11:19 AM.
Fair warning lightbulbs aren't a great load idea.
I would think that a small sealed glass volume isn't going to enjoy a temperature (and pressure) difference from 25C to -1XX C.
Don't beat yourself up, that kind of bulb is argon-filled to approx. atmospheric pressure, it's hardened glass type, designed to withstand 400+ °C, don't think it'll be an issue at all, I mean what could possibly do low temperature to an inert bulb made of glass ?
Obviously when cascade's running I'll make sure that we couldn't turn on the light bulb, in which case it would certainly break down yes ...
Last edited by Sk_rmouche; 06-21-2012 at 11:19 AM.
In most cases of "pressure" we see that things are designed to withstand positive pressure, but rarely "negative" pressure. I hope that bulb survives.
Chamber looks very good though.
We'll see, worst scenario, I would eventually go back to regular electric resistance. Light bulb are just fine to see how much power you are feeding into it, red hot glowing filament hmmm ... Priceless isn't it ?
Hey did you ever think about liquefy the argon within a classic light bulb by pouring some LN2 over the glass ?
Hello there !
I'm back to feed a little bit that old thread ! Well R14 sources didn't go very well, I'll buy some R1150 for the third stage. Compressor should be a GS26MLX from Danfoss. I've also bought a heating cable for the door of the cold room, and the two front regulator will work separately, one for cooling process with security to the light bulbs and heating cable, and the second one for heating process.
I hope all will be okay, despite lower HP on ethylene stage than what I would have got with R14.
Hi !
Just ordered a CAJ 2464Z from cold-ice
Someone knows that compressor ?
Looking forward to seeing more progress. Thought this project was going to be lost-to-time.
One drop of water off the evaporator on a hot bulb !!!
Last edited by wdrzal; 02-28-2013 at 01:06 AM.
The Laws of Thermodynamics say:
Zeroth Law: "You must play the game."
First Law: "You can't win."
Second Law: "You can't break even."
Third Law: "You can't quit the game."
Do you wanna Play Thermodynamics ????????
I'll make sure it doesn't happen
Hot process will be de-energized while cooling one is working.
R14 ordered, ten weeks of waiting :o
I received the last compressor anyway, it's a CAJ2464Z from Tecumseh, 34,5 cc and pure LBP motor. i hope it won't stress too much the second one ( 21cc)
I've also put a heating cable on the door to prevent excess frost during cooling process, just to open the door in any conditions.
SK_rmouche
Once you get your system running, do you have a way to measure electric power consumption? I would be interested to see how a 3-stage cascade compares to an autocascade of similar duty and temperature limit.
Kevin
Yes, I've two RMS wattmeter which would give you everything you want.
Hi
Finally received the R14, three months to get that bottle ! ...
I also ordered a LUVE condenser ( tubeless ), 2,73 kW @ 15k, it should do the job
I've found copper gasket for AKV, so maybe it could work with low temp. I bought a helium tank and a refrigerant leak detector to find small leaks.
That third stage will not have leaks, even a small one, not with a 900 euros bottle
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