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Post by Travis on Nov 28, 2018 15:18:27 GMT
I thought Chris had gotten a needle and seat. He was trying to see if they could be made out of stainless at a reasonable cost. Last I heard, the answer was now. Sometimes I think the issue is the definition of reasonable.
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Post by ChrisJ on Nov 29, 2018 0:00:06 GMT
I thought Chris had gotten a needle and seat. He was trying to see if they could be made out of stainless at a reasonable cost. Last I heard, the answer was now. Sometimes I think the issue is the definition of reasonable. I still haven't gotten around to cutting it open. Maybe one day... It's sitting on my desk at work. That said, the CA oil is believed to have 10% lard in it. I don't think anyone has tried running methyl formate without it but it'll probably be bad. Perhaps sometime has GEs methyl formate lard patent handy that explains it.
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Post by turbokinetic on Nov 29, 2018 3:14:34 GMT
I thought Chris had gotten a needle and seat. He was trying to see if they could be made out of stainless at a reasonable cost. Last I heard, the answer was now. Sometimes I think the issue is the definition of reasonable. I still haven't gotten around to cutting it open. Maybe one day... It's sitting on my desk at work. That said, the CA oil is believed to have 10% lard in it. I don't think anyone has tried running methyl formate without it but it'll probably be bad. Perhaps sometime has GEs methyl formate lard patent handy that explains it. Chris, if you want this needle and seat, it's yours for the asking but I see you already have one.
And as Travis says, reasonable is a relative thing. Some people would pay quite a lot to have a completely original-design and 100% healthy CA, with a new seat. Others would be plenty happy with a capillary tube system. In this unit the needle seems more or less serviceable, while the seat is eroded. I need to get the needle out of there and see a closer look at it to determine if it could be salvaged without any seriously difficult cutting open of the chamber. As-is, it would be really easy to put it back together with a copper coupling soldered in place.
I believe a capillary tube may be a little less energy efficient, but a lot more reliable and less stressful on the compressor. I want to try to design a capillary tube installation where the float chamber looks completely normal from inside the cabinet, with the filter and coiled tube completely in the insulation space between the compressor deck and the evaporator mount plate.
I see in the teardown of the CA compressor, that GE went to pretty good lengths to prevent the oil from getting to the condenser and rest of the system. That makes sense because lard would definitely solidify in the evaporator and form a very hard tallow, which might not flow back to the compressor.
I wonder what their reasoning for the lard was? I know the CA compressor is oil sealed, and wonder if it was used as a viscosity improver to help the oil sealing efficiency? I plan to send the oil off to have it analyzed, to see what the viscosity is. I am sure there's a modern oil which would take care of this unit. I am actually thinking that mechanical vacuum pump oil would fit the bill quite nicely. This compressor is, really, built like a vacuum pump in more ways than one.
I would like to see the patent on the lard oil for sure!
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Post by ChrisJ on Nov 29, 2018 19:25:12 GMT
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Post by ChrisJ on Nov 29, 2018 19:26:29 GMT
Looks like it was 2% lard.
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Post by Travis on Nov 29, 2018 22:00:03 GMT
Uh oh, lard is bad for CA’s too, not just people!
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Post by birkie on Nov 30, 2018 0:00:44 GMT
That's a most fascinating patent! A 90% reduction in NCGs by just adding lard is fairly good. I wonder if there is anything special about oleic acid, or if there are other (lighter) fatty acids that could work too. It'd be interesting to try olive oil as an alternative to lard, as it has a much higher oleic content, and might be a little softer in the evaporator. Actually, I'd be very curious if a little POE oil as an additive would have a similar effect, at least as far as catalyst poisoning is concerned. POE oils are fairly polar, and tend to form a one-molecule thick boundary layer over metals. It probably won't neutralize any formic acid, though. But maybe a drier might help with that. A pinch of fatty acid ester (a.k.a. biodiesel) might be even better at preventing NCGs, but that would probably solidify in the evaporator too.
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Post by ChrisJ on Nov 30, 2018 0:47:10 GMT
That's a most fascinating patent! A 90% reduction in NCGs by just adding lard is fairly good. I wonder if there is anything special about oleic acid, or if there are other (lighter) fatty acids that could work too. It'd be interesting to try olive oil as an alternative to lard, as it has a much higher oleic content, and might be a little softer in the evaporator. Actually, I'd be very curious if a little POE oil as an additive would have a similar effect, at least as far as catalyst poisoning is concerned. POE oils are fairly polar, and tend to form a one-molecule thick boundary layer over metals. It probably won't neutralize any formic acid, though. But maybe a drier might help with that. A pinch of fatty acid ester (a.k.a. biodiesel) might be even better at preventing NCGs, but that would probably solidify in the evaporator too. Someone on another forum recommended POE for that reason too.
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Post by ckfan on Nov 30, 2018 14:41:19 GMT
That is a fascinating read. I haven’t read through the whole thing yet though. So what I’m hearing is that anything that acts as a metal soap or will create a cover over the metal particles that act as a catalyst will work. So let’s put some downy in there and make the concoction smell good at least.
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Post by turbokinetic on Nov 30, 2018 17:55:46 GMT
..... So let’s put some downy in there and make the concoction smell good at least. LOL!
The current concoction smells like a forest fire combined with the twang of crushed cell phone batteries added in.
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Post by Travis on Nov 30, 2018 18:37:21 GMT
Only you would know what crushed cell phones batteries smell like.
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Post by turbokinetic on Nov 30, 2018 18:58:38 GMT
Only you would know what crushed cell phones batteries smell like. It was accidental, I promise....
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Post by turbokinetic on Dec 8, 2018 2:28:30 GMT
Hey folks, just a small update. I sent an oil sample off from this compressor. It is going through Caterpillar engine oil analysis. They can tell the viscosity and certain other engine related condition indicators. The main thing is the viscosity which interests me.
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