Glad to help, you can always install a sight glass to live view it.
Glad to help, you can always install a sight glass to live view it.
If you have a cooling question or concern feel free to contact me.
Actually some of the Polycold units did exhibit problems with oil, especially after switching from CFC's to HCFC's and then to HFC's. On the early larger 1100 units, dual 902's (in series) were used for the hot gas (defrost) supply only. At the place I contract to, I encouraged them to replace these with dual 905's also in series as Nol pointed out, but now being used in the full flow coming from the compressor discharge and into the water cooled condenser, and then on to the HXC stack.
On the latest Polycold 1102 units that use an HFC only charge, they have begun experiencing problems with oil migration once again in certain applications, and especially when run for extended periods of time. these units use 2 custom made oil separators (one large and one small) in series with the full system flow. We are now starting to replace the large oil sep with 2 Temprite 905's (in series), so this in essence gives us 3 oil separators in series when you count the small custom one that we leave in. So far this appears to be fixing the oil migration problem on these units.
Michael St. Pierre
- Worked 15 years for Polycold Systems
- Now Self-Employed
- Manufacture Heat Load Controllers
- Also do contract service work on Polycold units
Side note: I usually don't respond to PM's or emails regarding the projects that I post in the forums. I feel it's much more fair to all, to answer questions within the forum topics themselves.
kang-China...Well most of my reasons were pretty well explained on cap tube selection in early threads to this post, so instead of being redundant, I would suggest that you go back and review the information that was already presented.what about the captube in your AC-2 OR NEW machine AC-C
why ,the 2#,3#,4# in the same length, and i think, it use the different Refrigeration ,so the captube is different length.
And now a few questions for you kang from China... what is it that you are trying to do? Are you attempting to duplicate what I have done? If so, no problem, but I am curious because you are asking so many questions.
Michael St. Pierre
- Worked 15 years for Polycold Systems
- Now Self-Employed
- Manufacture Heat Load Controllers
- Also do contract service work on Polycold units
Side note: I usually don't respond to PM's or emails regarding the projects that I post in the forums. I feel it's much more fair to all, to answer questions within the forum topics themselves.
That's rather incredible. But do you think that may also be somewhat due to the very high flow in those units as compared to what we work with? Or the use of refrigerants?Actually some of the Polycold units did exhibit problems with oil, especially after switching from CFC's to HCFC's and then to HFC's. On the early larger 1100 units, dual 902's (in series) were used for the hot gas (defrost) supply only. At the place I contract to, I encouraged them to replace these with dual 905's also in series as Nol pointed out, but now being used in the full flow coming from the compressor discharge and into the water cooled condenser, and then on to the HXC stack.
I didn't realize the 905's were being used for the hot gas system, from most of the piping I saw it seemed to be post-condenser.
If you have a cooling question or concern feel free to contact me.
That's rather incredible. But do you think that may also be somewhat due to the very high flow in those units as compared to what we work with? Or the use of refrigerants?Actually some of the Polycold units did exhibit problems with oil, especially after switching from CFC's to HCFC's and then to HFC's. On the early larger 1100 units, dual 902's (in series) were used for the hot gas (defrost) supply only. At the place I contract to, I encouraged them to replace these with dual 905's also in series as Nol pointed out, but now being used in the full flow coming from the compressor discharge and into the water cooled condenser, and then on to the HXC stack.
I didn't realize the 905's were being used for the hot gas system, from most of the piping I saw it seemed to be post-condenser.
If you have a cooling question or concern feel free to contact me.
Actually it was originally two 902's in series, with the source being tee'd into the compressor discharge line (pre-water condenser). The 905's or custom Parkers as used by Polycold were added inline (full-flow) many years later, which filtered out the oil from both the hot gas defrost circuit and the main refrigeration stream.I didn't realize the 905's were being used for the hot gas system, from most of the piping I saw it seemed to be post-condenser
#1 I think it comes down to how much oil the particular compressor pumps, and #2 how miscible is the oil with the refrigerants in use.That's rather incredible. But do you think that may also be somewhat due to the very high flow in those units as compared to what we work with? Or the use of refrigerants?
A bit of Polycold history related to oil separation...
The 1000-1102 series Polycolds were all based on a Caryle (Carrier) 10 HP 37 CFM R-22 air conditioning compressor. In the first use (Polycold 1000), it was discovered that this compressor was a particularly high oil pumper. Polycold worked with Carrier on installing a 3rd ring on all the cylinders (of which there were six), in order to effect better oil control. This seemed to the trick at first, but many production units later, it was discovered that this was still not the case. The problem was further compounded by the owner/inventor Dale Missimer's refusal to let the engineers use full flow oil separators, insisting on the Phase Separators being enough to do the job (hence only allowing the use of two Temprite 902's on the hot gas defrost stream).
When Polycold moved on to the 1102 series, which required the use of HFC's for European compliance, there was no choice but to use full flow oil separation due to the poorer oil miscibility with said refrigerants (also Dale was out of the picture, having sold Polycold to Intermagnetics). However two series connected oil separators the size of the Temprite 905's were still not quite enough, so Polycold enlisted Parker to build some custom ones that they felt would solve the problem. But as the story goes, bigger is not always better. And even though they had implemented one that was twice the volume of a 905 for the first oil separator, in some applications they are still seeing the oil migration problem occur in these units.
So when I left Polycold, and started doing work for an independent Polycold service company, I was free to implement changes to the original designs. At first we tried a single full flow 905 on the 1100HC series, but this didn't quite do the trick. Next a 2nd one was added in series, and suddenly things began to improve. It seems that series filtration was the key, giving the final oil separator in the chain a non-saturated environment in which to work (see image below). Now we are taking this idea into the 1102HC units, and adding a 3rd series oil separator by replacing the large #1 custom Parker oil separator with two 905's, and retaining what used to be the #2 oil separator, moving it into the 3rd position.
Last edited by mytekcontrols; 03-06-2011 at 06:39 AM.
Michael St. Pierre
- Worked 15 years for Polycold Systems
- Now Self-Employed
- Manufacture Heat Load Controllers
- Also do contract service work on Polycold units
Side note: I usually don't respond to PM's or emails regarding the projects that I post in the forums. I feel it's much more fair to all, to answer questions within the forum topics themselves.
Interesting.
If you consider it, the entire autocascade is one long serial separator, so it's funny that "serial was the answer" when it was already sort of present.
In your blend using HC's then are you having any issue? Or is the increased miscibility playing out nicely.
It seems to me that coalescent could use an improvement, either the oils blowing through the catcher or just the flow is so high that the atomized droplets are flying on out. The design itself really only features a single attempt to remove oil, it surprises me that helical would not perform better in this application.
If you have a cooling question or concern feel free to contact me.
@Michael and Adam: Thank you gentlemen, you answered my questions. Cheers.
Really? I figured I was just confusing everyone!
I look forward to seeing your project. I found a decent source of butane/isobutane/(little bit of propane) mix as well if you need it.
If you have a cooling question or concern feel free to contact me.
hi,
review the information,but i don't find that
i ask you cap tube,and i will know you design principle,
as so i wont to know this cade(AC-2)design principle.
I'll be attempting to duplicate AC-2
must need help form you
and mytek your AC-2 will to work the -150℃ OR -160℃
and the refrigeration is ..R14,Ar can do that
The Revco -150 and -140s have gotten away from series seperators and switched to parallel. Their test showed that with the volume and velocity of gas they were pushing, it was overloading the oil sep when they were in series.
The R600 came from National welders.
Youcan try here for small quanities of most any gas.
http://www.scottgas.com/
Thank you! I just sent in a request.
If you have a cooling question or concern feel free to contact me.
kang-China...Sorry to disappoint you, but I don't have an exact method of choosing cap tube sizes for an AutoC. With that said, here are links to earlier posts that explain my methodology: Post #109 -and- Post #112review the information,but i don't find that
i ask you cap tube,and i will know you design principle
kang-China...If all you want to do is create an exact clone of the AC-2 unit, taking the time to completely read through this thread is the best way to accomplish this. Because nearly every single detail has been covered to allow anyone with basic refrigeration skills to do this. It is only when one decides to go beyond this, or take a different approach, that the knowledge provided here might not be sufficient to the task.I'll be attempting to duplicate AC-2 must need help form you
So my suggestion to you, would be to build this unit as I have shown, and charge it with something equivalent to what I have used. Then play around with it, by trying different refrigerants and/or quantities of such to gain a better understanding of how the system actually works before attempting to build something entirely different.
So please, enough questions for now and I wish you luck on your AutoC journey
Remember: Take the time to thoroughly review and understand all the posts related to the AC-2 unit
Michael St. Pierre
- Worked 15 years for Polycold Systems
- Now Self-Employed
- Manufacture Heat Load Controllers
- Also do contract service work on Polycold units
Side note: I usually don't respond to PM's or emails regarding the projects that I post in the forums. I feel it's much more fair to all, to answer questions within the forum topics themselves.
ultralo1..Very interesting, and not what I would have thought. Everything that I have experienced and learned over the years, suggests that series filtering would always be superior to parallel. So were those tests conclusive? Meaning did they try using a single oil separator with the same volume as the two in parallel? If not, then their problem may have just been related to being undersized.The Revco -150 and -140s have gotten away from series seperators and switched to parallel. Their test showed that with the volume and velocity of gas they were pushing, it was overloading the oil sep when they were in series.
Last edited by mytekcontrols; 03-09-2011 at 06:17 AM.
Michael St. Pierre
- Worked 15 years for Polycold Systems
- Now Self-Employed
- Manufacture Heat Load Controllers
- Also do contract service work on Polycold units
Side note: I usually don't respond to PM's or emails regarding the projects that I post in the forums. I feel it's much more fair to all, to answer questions within the forum topics themselves.
if the machine is working -150℃ OR -160℃,and what's the refrigeration we can use ,and how much cade in the cooling like your AC-2
And what about R50
and in the Aoutcascade system use this
R14 in 3#
R50 Ar in 4#and sub-cooler
and another like your AC-2
what will happen
Cade? I'm not sure the term.
But methane could work but as you go further and further downstream you need more flow, so a larger system.
Certain things you will need to try yourself.
If you have a cooling question or concern feel free to contact me.
kang-China...The possibility of using R50 in an AutoC was discussed in Post #285And what about R50
and in the Aoutcascade system use this
R14 in 3#
R50 Ar in 4#and sub-cooler
Michael St. Pierre
- Worked 15 years for Polycold Systems
- Now Self-Employed
- Manufacture Heat Load Controllers
- Also do contract service work on Polycold units
Side note: I usually don't respond to PM's or emails regarding the projects that I post in the forums. I feel it's much more fair to all, to answer questions within the forum topics themselves.
Something we haven't discussed here, evaporator design.
What kind of evaporator do you normally use in your systems? Is it just a simple loop of tubing?
If you have a cooling question or concern feel free to contact me.
Nol...Hmm... how best to answer this? Well to put it simply, no different then any other system. Whether that be Single Stage, Cascade, or AutoC, the principles remain the same. But in my case, yes I have used a coil of tubing, or a machined copper bar (see image below).Something we haven't discussed here, evaporator design.
What kind of evaporator do you normally use in your systems? Is it just a simple loop of tubing?
Essentially basic evaporator design 101: Allow sufficient room for the refrigerant to fully expand, minimize pressure drop, and minimize the temperature gradient between the refrigerant and the actual heat load.
Image: Vacuum Insulated Cold Head (w/attachment option for heat absorbing array), as used on the AC-3 project.
Michael St. Pierre
- Worked 15 years for Polycold Systems
- Now Self-Employed
- Manufacture Heat Load Controllers
- Also do contract service work on Polycold units
Side note: I usually don't respond to PM's or emails regarding the projects that I post in the forums. I feel it's much more fair to all, to answer questions within the forum topics themselves.
That's really enough eh? I'm trying to work my way through a bunch of patent papers and books on evaporator design, we need some changes in ours
If you have a cooling question or concern feel free to contact me.
hi,mytek
i looked the post thank you very much
the defrost valve in polycolde
the valve's brand is SPORLAND .
why don't used the DANFOSS
or maybe SPORLAND IS better than DANFOSS
by your rule of thumb which is better
Nol...Well if I remember right, it's enough to handle 50 watts on the attachment end of the Cold Head with a temperature gradient <= 5C. Not really sure how it'd do at 300 watts.That's really enough eh? I'm trying to work my way through a bunch of patent papers and books on evaporator design, we need some changes in ours
Note(1): It would seem that the "Stepper" design that I see being used for CPU cooling, has proportionately more surface being cooled on the circumference then on the CPU side. This seems like a waste of material and extra machining. Where as a low profile design would seem to be more efficient.
Note(2): Has anyone measured the surface temperature versus the refrigerant temperature of any of the currently used evaporator designs while under full load? If not, then how can anyone know if a given design is any better (or worse) than another?
Last edited by mytekcontrols; 03-10-2011 at 06:16 AM.
Michael St. Pierre
- Worked 15 years for Polycold Systems
- Now Self-Employed
- Manufacture Heat Load Controllers
- Also do contract service work on Polycold units
Side note: I usually don't respond to PM's or emails regarding the projects that I post in the forums. I feel it's much more fair to all, to answer questions within the forum topics themselves.
kang-China...My rule of thumb? I'd have to say so long as the valve is shown to be reliable, and works within the anticipated temperature range of the application , it is good. Why not Danfoss instead of Sporlan? The Sporlan B6 (as used in a Polycold unit for defrost) has proven itself to be reliable in this application, is more readily available here in the USA (where Polycold units are manufactured), and I would imagine is cheaper to buy as compared to a Danfoss equivalent.the defrost valve in polycolde
the valve's brand is SPORLAND .
why don't used the DANFOSS or maybe SPORLAND IS better than DANFOSS
by your rule of thumb which is better
Another alternative would be ASCO, which is the brand that Telemark uses in their units.
Michael St. Pierre
- Worked 15 years for Polycold Systems
- Now Self-Employed
- Manufacture Heat Load Controllers
- Also do contract service work on Polycold units
Side note: I usually don't respond to PM's or emails regarding the projects that I post in the forums. I feel it's much more fair to all, to answer questions within the forum topics themselves.
and what about danfoss in the USA
if i want to buy some SPORLAN what can i do
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