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Post by birkie on Jun 4, 2017 1:41:42 GMT
Is this why the CA's compressor's displacement is 3 cubic inches? That, and the fact it has to pull down to 26"+HG in a vacuum? Wonder if it also has to do with why the passages in the CA's evaporator are huge? Yup. I think the CA compressor pumps 4x more by volume than a DR3. Those low-pressure refrigerants are very thin at evaporating temperatures. |
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Post by birkie on Jun 9, 2017 17:42:25 GMT
Refrigerant grade 227ea is over $1,200 wholesale for 30 lbs Ok, so I explored some alternative avenues to get the stuff domestically, and got a slew of callbacks this morning. Here's what I found Scientific/technical grade is over $85+/lb, so that's out. I found a source for virgin R227ea at $15-20/lb, ship them a tank and they'll fill as much as you'd like, although at a date/time that is convenient for them. There's an active reclamation/recycling market, particularly with data centers. Reclaimed and purified R227ea can be found at $10-15/lb in 50lb quantities. You can get full FM-200 tanks from companies that dismantle data centers, at about $4-5/lb. FM-200 is just R227ea plus pressurized nitrogen (360 psi), like a carbonated beverage except with Nitrogen. There are a 54 and 62 lb tanks on ebay now. The gentleman says they get the stuff all the time. It's cheap, but we'd have to figure out how to open the tanks, then distill the nitrogen out of the solution. It may actually be feasible to do this using the coldspaces method of chilling the tank so the R227ea condenses, but labor intensive, as you'd probably need to two it twice (once to get rid of the high-pressure nitrogen, and another to get rid of the rest of the dissolved nitrogen). So, I think there's a chance of this actually happening. I glanced back at the numbers and it strongly suggests that it would work really well without any modification; just about the same power draw, but 20% higher capacity. It's just that high vapor density. |
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Post by Travis on Jun 9, 2017 22:10:30 GMT
I don't think $15-20/lb is bad.
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Post by birkie on Jun 10, 2017 1:10:14 GMT
I don't think $15-20/lb is bad. No, not bad at all, especially if they're willing to dispense the amount we ask for. I think that would be the best way to cut to the chase and see if the stuff works as predicted, and is any better or worse than R134a or R152a with respect to noise, oil return, etc. coldspaces : Would you be interested/willing to give it a try in one of your machines, if a canister of this refrigerant were to magically appear on your doorstep? (Well, not magic. Logistics). |
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Post by coldspaces on Jun 10, 2017 1:15:40 GMT
I don't think $15-20/lb is bad. No, not bad at all, especially if they're willing to dispense the amount we ask for. I think that would be the best way to cut to the chase and see if the stuff works as predicted, and is any better or worse than R134a or R152a with respect to noise, oil return, etc. coldspaces : Would you be interested/willing to give it a try in one of your machines, if a canister of this refrigerant were to magically appear on your doorstep? (Well, not magic. Logistics). You know I would try it!! |
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Post by birkie on Jun 10, 2017 1:32:10 GMT
You know I would try it!! Awesome! At some point, I'll send you a private message about shipping, timing, etc. First and foremost, though, is probably figuring out how much is needed for the machine(s?) it'll be going in to. |
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Post by birkie on Aug 12, 2017 19:21:16 GMT
An update: A few of us have been communicating regarding logistics of pairing guinea pig machines with refrigerants. In that conversation, Gill mentioned that he and Travis once talked about trying R124 too. It's an HCFC (so it's going to eventually be banned), but it looks like some production of it might be allowed up to 2030. They're not sharply scaling it back like they're doing to R22. Anyway, it's available at reasonable prices through wholesalers as a refrigerant. I ran some calculations on it and ... WOW! R124 is also a very close match SO2 as well! It looks like it's very weakly miscible in mineral oil; practically immiscible below 114F. That's promising for oil return. Here's it's data sheet www.chemours.com/Refrigerants/en_US/assets/downloads/h62445_hcfc124_push.pdf Here's how it compares with SO2, R227ea, R1234ze, R134a, R152a as a drop-in replacement in the same hypothetically ideal compressor, with 15F low-side and 100F high-side saturation temperatures: Power Draw (relative) ------- SO2: 1 R124: 0.92 R227ea: 0.97
R1234ze: 1.12 R152a: 1.41 R134a: 1.52 Capacity (relative) -------- SO2: 1 R124: 0.99 R227ea: 1.18 R1234ze: 1.29 R152a: 1.55 R134a: 1.73 COP ----- SO2: 5.62 R124: 6.47 R227ea: 6.80 R1234ze: 6.50 R152a: 6.19 R134a: 6.40 Head pressure differential (relative) ---------- SO2: 1 R124: .92 R227ea: 1.08 R1234ze: 1.17 R152a: 1.41 R134a: 1.55 Mass flow (relative) ----------- SO2: 1 R124: 2.35 R227ea: 3.57
R1234ze: 2.65 R152a: 1.91 R134a: 3.28 Molar flow (relative) ------------ SO2: 1 R124: 1.10 R227ea: 1.35
R1234ze: 1.49 R152a: 1.85 R134a: 2.05 So I'd say it's an even closer match than R227ea by a hair, and it's more "normal" as far as density. In any case, we now have two outstanding contenders for the DR drop-in replacement challenge! Appendix: Here's a little p/t comparison chart.
| SO2 | R124 | R227ea | R1234ze | R152a | R134a | | -5 F | 11.6" vacuum | 9.3" vacuum | 5.1" vacuum | 2" vacuum | 2.4 psig | 4.1 psig | | 5 F | 6.1" vacuum | 3.6" vacuum | 0.9 psig | 2.7 psig | 6.9 psig | 9.1 psig | | 15 F | 0.4 psig | 1.6 psig | 4.9 psig | 7.2 psig | 12.2 psig | 15.0 psig | | 85 F | 51.1 psig | 48.8 psig | 61.0 psig | 67.8 psig | 83.8 psig | 95.2 psig | | 95 F | 63.8 psig | 60.1 psig | 72.9 psig | 82.1 psig | 100.4 psig | 114.0 psig | | 105 F | 78.3 psig | 72.7 psig | 88.8 psig | 98.1 psig | 119.2 psig | 135.0 psig |
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Post by ckfan on Aug 16, 2017 13:40:02 GMT
Travis and I are going to visit Gill this weekend with those guinea pigs in tow. It should be a fun time experimenting!
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Post by birkie on Aug 16, 2017 15:47:06 GMT
Travis and I are going to visit Gill this weekend with those guinea pigs in tow. It should be a fun time experimenting! Wow, that was fast. This is exciting! |
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Post by stlvortac on Aug 17, 2017 2:03:41 GMT
Exciting news!! Can't wait to find out the results. What applications are R124 and 227ea normally used in?
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Post by birkie on Aug 17, 2017 2:28:58 GMT
Exciting news!! Can't wait to find out the results. What applications are R124 and 227ea normally used in? As far as I can tell, R124 mostly used as a refrigerant; one of the less popular ones, but available on the wholesale market and easily obtainable by people like Gill. R227ea mostly mixed with Nitrogen and used as a "clean agent" fire extinguisher in data centers, museums, and archives where it can extinguish fires without leaving a residue and destroying things in the room. It's used occasionally as a refrigerant, but disproportionately expensive when sold that way. |
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Post by kennytpb7 on Aug 19, 2017 1:22:02 GMT
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Post by kennytpb7 on Aug 19, 2017 1:26:24 GMT
I've heard about flushing the S02 out of the system but is there any reference manual for the novice (me) to do this in order to fix the line. I'm sure the compressor is fine, however, one of the lines was probably damaged in movement as the inside was oily and had the S02 smell. The guy helping move it decided it was easier to load it on its side--my heart sank when I saw the oil--I first thought it was melted snow, but nada.
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Post by birkie on Aug 19, 2017 2:16:02 GMT
I've heard about flushing the S02 out of the system but is there any reference manual for the novice (me) to do this in order to fix the line. I'm sure the compressor is fine, however, one of the lines was probably damaged in movement as the inside was oily and had the S02 smell. The guy helping move it decided it was easier to load it on its side--my heart sank when I saw the oil--I first thought it was melted snow, but nada. The concern is corrosion from the acids formed with SO2 interacts with the water in air. So what you want to do is displace the air with an inert gas (nitrogen), and/or evacuate it (really only an option if you fix the leak first). If you lack the tools, probably the best thing to do is figure out where the leak is, temporarily patch it with tape, putty, or whatever you have on hand, and find someone who can do it. |
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Post by ckfan on Aug 19, 2017 14:08:40 GMT
Aww, I've always loved that style of flat top. Very good curves.
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