Morphing Air Conditioner into Autocascade System

Quote:

---

Man, I wish I could have snuck in and placed a heavy duty humidifier right next to the evaporator....and then removed it before you arrived in the morning. That might have made for some hilarious results.

---

That would've done the trick alright :yepp:

Quote:

---

Better yet, get a big drum of olive oil, proper it under, would have frozen it all up, and when you removed the bucket it would be incredibly wierd looking as the outside started to melt!

---

And made for one hell of a mess :rolleyes:

Quote:

---

OMG, how did i miss this thread .... its damn cold!

---

Yep, and it'll be even colder when I put it in a vacuum (I'm guessing -145C under normal ambient conditions in our shop).

This pic shows a very good physical comparison of a commercially made product (Polycold P-75), and what can be done with a Home Depot purchased AC unit. Now obviously the P-75 is missing its panels, but if nothing else, it shows the tremendous reduction in size that was achieved (not to mention, 1/2 the power consumption).

:shocked:

HAHA I love it :clap:

You did a great job on that !

Half as big, more powerful, less power draw. What more can you ask for?

Nice work. :up:

What's the HX stack like on the P75 though, isn't it pipe in pipe in a massive round coil? I bet they could save space, plus again condenser could be smaller! You are an innovator and an inventer indeed :)

Yes Adam, there is a lot of wasted space inside the stack area, and like you implied, they used a very large diameter mandrel to bend up the coils (tube-in-tube coaxial design).

Polizei -- Long time no hear from. How are your projects going? And yes it does make a difference using a rotary vs a reciprocating compressor when it comes to efficiency.

But the cart still rolls better, uses zero power, and doesn't require any ozone depleting or greenhouse potential gases ;)

Quote:

---

Originally Posted by mytekcontrols

Polizei -- Long time no hear from. How are your projects going? And yes it does make a difference using a rotary vs a reciprocating compressor when it comes to efficiency.

But the cart still rolls better, uses zero power, and doesn't require any ozone depleting or greenhouse potential gases ;)

---

Projects? I have barely any time to fiddle with air cooling, let alone getting EPA certified to start playing with gasses. No tools, no workshop, no money, no phase for me. I pop in when I can to learn. :)

Splendid job

it would be possible to make the meme job to cool down a processor?

I thought i've seen everything when i saw the cold_ice's & bazx quality made cascades, but You sir beat them all with this superb job. Everyone knows how hard is to make a aestetically good looking AC and even how hard - if not nearly impossible - is to make a good 3-stage+ autocascade!

Beyond words really. If you make a processor direct-die evaporator AC refrigerator, i'll vote to make You Xtreme Legend!

:up:

Quote:

---

it would be possible to make the meme job to cool down a processor?

---

Yes, but due to the modern day requirement in heat load capacity (normally 250 watts), it would take about a 40% increase in compressor mass flow to achieve it on the system that I built. Would also require increasing captube flows proportionately.

Of course this also depends on the temperature required. If -90C would be sufficient for your needs, then simply eliminate one stage, increase the captube flows by at least 25-30%, and eliminate most of the R14, and NO argon.

Quote:

---

Beyond words really. If you make a processor direct-die evaporator AC refrigerator, i'll vote to make You Xtreme Legend!

---

Thanks tiborrr :), but I doubt that I'll be able to find the time in the near future to do so. It looks like we'll have to see what Nol ends up doing in his autocascade project, or perhaps Gomeler (I have this feeling that we haven't seen the last AC out of him).

:bounce: Stay Tuned: Pretty soon I'll reveal the final results for this project in the actual application, under a 10-6 Torr vacuum process.

Thanks Michael,
Now I have a 25 page reread!! Nice Job

Quote:

---

Now I have a 25 page reread!!

---

I'm not sure if this is a good thing, or a bad thing :shrug: :D

Quote:

---

Originally Posted by mytekcontrols

Thanks tiborrr :), but I doubt that I'll be able to find the time in the near future to do so. It looks like we'll have to see what Nol ends up doing in his autocascade project, or perhaps Gomeler (I have this feeling that we haven't seen the last AC out of him).

---

Just got a quote on R170(CHEAP!)... I have a HUGE reciprocating compressor sitting here.. two huge condensers.. a large autocascade is cooking on the back burner. I need a shop like yours :up:

Quote:

---

Originally Posted by mytekcontrols

I'm not sure if this is a good thing, or a bad thing :shrug: :D

---

A fantastic thing. This thread has been a huge resource, learned more here on autocascade theory than any other thread. Has this been sticky'd yet?

Quote:

---

is it like foam in a can?

---

Nope. It's a two part spray foam made by instapak.

Quote:

---

Just got a quote on R170(CHEAP!)... I have a HUGE reciprocating compressor sitting here.. two huge condensers.. a large autocascade is cooking on the back burner. I need a shop like yours

---

gomeler -- Where do you store and work on all this stuff now? Is it something like the basement shop that Nol has (see pic I found online below)?

Yep no doubt about it, I am lucky to have access to a good shop, with professional tools, torches, and a decent supply of refrigerants. Too bad you don't live in my area, since I know the people I work for would probably take on another qualified part time refrigeration person, and this would give you the same access I have. Plus it would give you a chance to work on some really big autocascades.

Nol's Mad Scientist Laboratory

I used to have a single-car garage in which I stored all my benching gear and refrigeration gear. Now I live in a house with no garage so I'm forced to move whatever tools I'm using outside, work for a few hours, and then move back into the house at nightfall. The garage was perfect though, I had 3 desks, 1 for benching and 2 for building, and plenty of space to keep everything organized. No worries though, just pieced together 2 single-stages doing the "patio shuffle" over the course of 2 days :up: When I move out to California I'll have to at least visit your shop and see what a real workshop is like :D

Hahaha that pictures years old. I then switched to nice metal framed work benches, and removed the couch and rugs and all that, got much more organized and clean. Then had wiring added and such to each stand, and then had to move all of it to my fathers home when my mother moved. So now that's all crammed in a very tight 12 by 12 foot square.
Should post a picture sometime ;)

Quote:

---

Originally Posted by n00b 0f l337

Hahaha that pictures years old. I then switched to nice metal framed work benches, and removed the couch and rugs and all that, got much more organized and clean. Then had wiring added and such to each stand, and then had to move all of it to my fathers home when my mother moved. So now that's all crammed in a very tight 12 by 12 foot square.
Should post a picture sometime ;)

---

Definitely.

Whats the mini Drill Press for?

Kicking ass and taking names of course ;)
Decent press that it was, I used it mainly for drilling holes in aluminum angle.

Quote:

---

I used to have a single-car garage in which I stored all my benching gear and refrigeration gear. Now I live in a house with no garage so I'm forced to move whatever tools I'm using outside, work for a few hours, and then move back into the house at nightfall. The garage was perfect though, I had 3 desks, 1 for benching and 2 for building, and plenty of space to keep everything organized. No worries though, just pieced together 2 single-stages doing the "patio shuffle" over the course of 2 days

---

Kinda reminds me of my situation about 20 years ago...
I was renting a place that had been converted from tin sided barn into a 2 room apartment (1 room was the combination kitchen and living room, and of course the other was the bedroom).

I later convinced the landlord to let me convert the attic space into a workshop. He agreed, and over the course of several months, and scrounging around for free left-over materials from construction sites, my lab was born. It didn't have any windows, but this also turned out to be part blessing when I accidentally started a small fire when torching on a unit. The fire I got under control quickly, but boy did it create a lot of smoke. I was nervous that the landlord would see it (he lived on the same property), and then shut down my operation. But because there were no windows, the only escape for the smoke was through whatever cracks it could find leading out of the attic space. It took quite a few hours for the smoke to finally dissipate, all the while being stealthy while doing so. I never got caught.

Quote:

---

When I move out to California I'll have to at least visit your shop and see what a real workshop is like

---

Well it isn't my shop, but I'm sure I can arrange a tour :)

Quote:

---

Hahaha that pictures years old. I then switched to nice metal framed work benches, and removed the couch and rugs and all that, got much more organized and clean. Then had wiring added and such to each stand, and then had to move all of it to my fathers home when my mother moved. So now that's all crammed in a very tight 12 by 12 foot square.

---

Nol -- I thought it was great :up: Just what an experimenters place should be.

Quote:

---

Originally Posted by mytekcontrols

Kinda reminds me of my situation about 20 years ago...
I was renting a place that had been converted from tin sided barn into a 2 room apartment (1 room was the combination kitchen and living room, and of course the other was the bedroom).

I later convinced the landlord to let me convert the attic space into a workshop. He agreed, and over the course of several months, and scrounging around for free left-over materials from construction sites, my lab was born. It didn't have any windows, but this also turned out to be part blessing when I accidentally started a small fire when torching on a unit. The fire I got under control quickly, but boy did it create a lot of smoke. I was nervous that the landlord would see it (he lived on the same property), and then shut down my operation. But because there were no windows, the only escape for the smoke was through whatever cracks it could find leading out of the attic space. It took quite a few hours for the smoke to finally dissipate, all the while being stealthy while doing so. I never got caught.


Well it isn't my shop, but I'm sure I can arrange a tour :)

---

Hahahah that's great man. The most desperate I've been was brazing together a single-stage for myself in my dorm room. I didn't tell anyone on my floor what I snuck into my room, they would have been pissed with the co2 cylinder and mapp cylinders :D Since then though I've tried to work in large open rooms(said garage) or outside. You've got me beat, I would have cut sky-lights into the roof :eek:

Quote:

---

Originally Posted by sjg0

Definitely.

Whats the mini Drill Press for?

---

problably drilling holes. i have one too, its pretty good at drililng holes:p:

Here are my results with the AC-2 unit under actual operating conditions at High Vac (approximately 2x10-6 Torr).

• Comp Suction Pressure = 26 psig
• Comp Discharge Pressure = 148 psig
• Comp Discharge Temperature = 67.1C
• Condenser Air Temperature = 21.8C
• Compressor Suction Temperature = 0.5C
• Veeco MS-17 Cold Probe = -139.6C

I had to boost up the refrigerant charge to completely work the cold probe (forgot about radiant heat load coming from the walls of the cold probe vacuum chamber). Here is my estimate of the present charge:

• 7oz R123
• 4oz R22
• 85psi R170
• 85psi R14
• 45psi Argon

The 1oz boost in the R22 really helped to make a better connection between the low and the high stages of the autocascade, and can also be seen in the moderate pressures, even though more gases were added.

If I get a chance I'll try to do a complete recharge with this new charge to verify repeatability under the same conditions. Judging by the compressor pressures, it appears that there may still be room for more Argon and even lower temps.

So, uh, what is going on in that picture? :yawn:

What's the bottom machine?

Quote:

---

Originally Posted by teyber

problably drilling holes. i have one too, its pretty good at drililng holes:p:

---

lol. Wise-A$$ :shakes:

@mytekcontrols: I will be impressed when that thing can reach -250c

Quote:

---

Originally Posted by Polizei

So, uh, what is going on in that picture? :yawn:

What's the bottom machine?

---

Think he said something about a deep vacuum mass-spectrometer.

Quote:

---

Originally Posted by sjg0

lol. Wise-A$$ :shakes:

@mytekcontrols: I will be impressed when that thing can reach -250c

---

Uhh...I think it is a feat in itself that he made a machine capable of -140*C in the space of a small window air conditioner..

That is very impressive. Can I ask how much it cost you to make that unit ? :o

Quote:

---

Originally Posted by [XC] Lead Head

Uhh...I think it is a feat in itself that he made a machine capable of -140*C in the space of a small window air conditioner..

---

I have high expectations. What can i say? :D

Quote:

---

So, uh, what is going on in that picture?
What's the bottom machine?

---

I'll start with your 2nd question first; The bottom machine is called a Helium Mass Spectrometer leak test station (HMS for short). It consists of: A High Vac diffusion pump, mechanical forepump (basic vacuum pump), A Cold Trap, and what is called a Cee Tube (consists of: Ion Gun, Filament Assembly, and Ion Collector). It also has a Roughing Pump, and a throttle valve between the Low Vac and the High Vac manifolds.

The entire purpose of this machine is to sense very small traces of helium while pumping on an external vessel, or in our case, refrigeration unit under leak test. So the basic idea is to either spray helium around the unit under test, or to "bag it" and fill the bag with helium. Since the unit will be under a vacuum (evacuated by HMS vacuum pumps), helium will travel through any holes that are present to the HMS to be detected.

Note: Helium is not readily available in our atmosphere, thus making it an excellent tracer gas for leak checking.

The HMS is a highly sensitive device, and will detect leaks of extremely small size, thus making it an excellent tool for leak checking refrigeration units, and especially cascade or autocascade systems with a multitude of solder joints.

If you guys are interested, I can post some pics of the HMS inner workings.

As for what is going on in the picture; I have the HMS operating in its High Vac mode, and the AC-2 unit is being used to cool its cold trap. The cold trap's purpose is to greatly enhance the High Vac's efficiency by trapping any water vapor that is present, something that is difficult for the diffusion pump to do on its own.

Quote:

---

@mytekcontrols: I will be impressed when that thing can reach -250c

---

Now wouldn't that be something :shocked:

Quote:

---

That is very impressive. Can I ask how much it cost you to make that unit ?

---

It cost about $800, including refrigerant that I bought from the people I work for. This price is inclusive of the AC unit and the custom front panel costs. Not bad when you consider what it is doing, and how much something similar in a commercial product would cost.

I think a MOD should copy the first 603 posts (it's complete @ that point)to the Extreme hall of Fame.(to limit reading to 25 pages) There is no auto-cascades documented there. Nor anyone who took the time to explain and post like Mytek did about this auto-cascade build & it should be there to recognize his work & time given to documenting & teaching others. :up: This thread can be allowed to continue to grow for further Q&A to benefit the forum.

Walt

Wholly agreed

Over the last week I started to notice a degradation in performance (evap temperature warming up). At first I thought it might be an oil freeze-up problem due to the extended run time, and the fact that I am still using the stock oil charge that came with the compressor. However when I powered the unit down and allowed it to fully warm-up, I noticed that the static balance pressure had dropped significantly (about 10 psi).

The pressure drop equated to approximately 1 psi per day. Yes, a very small, and potentially difficult leak to find :mad:.

My biggest worry was that the leak might be somewhere in my heat exchanger stack :eek:!?@#! Luckily it wasn't, and I was able to pinpoint it to the stem seal on the ASCO solenoid valve being used for buffering :clap:

Not having a sure fire method of fixing the problem, I opted instead to replace the valve with one of the valves we use to regulate cooling on the Polycold units I do service work on. This valve (Sporlan XUJ) is very similar to the Sporlan A3F1 which is hermetically sealed, and comes with 1/4" flare nipples on the In and Out connections. Leak fixed!

Now my next step will be to recharge and retest the unit. Because the leak was probably influencing my previous test results, I will also backtrack to an earlier lower quantity charge blend, and then adjust it up with measured additions to re-establish the best charge for this unit. I'll post the results sometime this coming week.

How long is your testing period usually?
It seems that you have been testing this unit for quite some time now...

And sorry to hear about the leak. It was looking so perfectly!

let us wait for suite with impatience:)

Quote:

---

How long is your testing period usually?
It seems that you have been testing this unit for quite some time now...

---

Good question Jack :up:

At this point I guess you could say I am in the life testing mode (basically turn it on, let it do its thing, and see how long it will work without failing). Keep in mind that the system it is connected to is fully operational the entire time. So it really isn't like many of the earlier tests, where I was trying to establish proper captube sizing, refrigerants to use, and load capacities for various applications.

As for unit design; everything is completely defined and most likely locked in, and should be unaffected by this last phase of testing. That is, unless a major problem is discovered along the way.

When this is concluded; some one should be able to follow this thread, build a duplicate unit, and obtain exactly the same results. If they opt for a different selection of refrigerants, or wish to scale the system size, then it is also my hope that enough information can be derived from the various tests and discussions, to aid in their success.

And of course like many of the other threads on this forum, this thread is a public form of my lab journal (in this public forum I have been covering the high lights, you would be amazed at all the test sheets and charts I have in my real journal).

I would be amazed if i could see and read those sheets ;)

thank you big time this thread has helped me a lot in understanding
and your ability is astounding in this field

alltho ss is where eye will start

Quote:

---

Originally Posted by mytekcontrols

And of course like many of the other threads on this forum, this thread is a public form of my lab journal (in this public forum I have been covering the high lights, you would be amazed at all the test sheets and charts I have in my real journal).

---

I'm envisioning a couple 6" binders full of graphs and spec sheets. ;)

Incredible project, reading this thread was like reading a good book, i couldn't wait for the next page :)

I also found out that my theoretical thoughts about auto cascades were proven right, and i learned a lot of new stuff. I feel guilty i stopped working on cascades years ago :(

Recently my "grand daddy" cascades II stage compressor decided to die, after reading this thread i think of copying your auto cascade using my I stage compressor :)

Maybe its time for a comeback to phase change, it would be interesting to find out how much have i forgotten after all this time and to test my new toys and skills which i usually use while working on cars :)

Quote:

---

Recently my "grand daddy" cascades II stage compressor decided to die, after reading this thread i think of copying your auto cascade using my I stage compressor

---

berkut -- I hope you do and I wish you very good luck on this endeavor :up:

Here are the latest specifications after fixing the leak.
Charge:

• 7oz R123
• 3.5oz R22
• 75psi R170
• 75psi R14
• 48psi Argon

Performance (with 21.5C Ambient Air Temperature):

• Suction Pressure = 26psi
• Discharge pressure = 162psi
• Compressor Discharge Temp = +70.3C
• Compressor Suction Temp = +3.2C
• Cold Probe Average Temp = -141.9C

The static balance pressure just after charging was 225psi. This dropped by 20psi after having been run, and then allowed to warm up over 2 days (refrigerant soak-in). Final BP appears to be about 205psi, although I anticipate this will rise and fall a couple of psi depending on the ambient conditions in the room.

The R123 and R22 were first charged into a small tank (modified steel suction accumulator) that was being weighed on a refrigerant charging scale. It was tricky, since I couldn't leave the hose connected to the tank while weighing, for fear of altering the readings. This necessitated adding the liquid in small bursts, closing the tank valve, disconnecting the hose, and then verifying the weight each time.

Once the proper amount of both refrigerant liquids was in the small tank, I then added it to the evacuated AC-2 unit. This was then followed by adding the gases based on pressure. In order to insure that all the liquid from the tank got transferred into the unit; I added the refrigerant gases through the top of the tank, and extracted the liquid from the bottom. Keeping the tank connected inline throughout the entire gas charging process.

The end results were quite good, letting me break the -140C barrier :D

Great job on breaking the -140C barrier with a single compressor. Just wondering about the "refrigerant soak-in" - What happens there, how can the static presure go down if it's a sealed system ?

"Soak-In" --- quite common in mixed refrigerant charge systems, and even more pronounced when the compressor utilizes some type of oil for lubrication.

Reason:
When initially charged, the warmer boiling refrigerants (liquids) don't fully mix with the oil. Also, the mixture of refrigerants hasn't 100% blended, or gone into solution with one another.

After being allowed to sit for many hours (may even take up to 2 days), everything blends as much as it can for a given room temperature (gases dissolve into other gases, gases dissolve into liquids, liquids dissolve into each other, ect.). As this all occurs the static BP will drop. Sometimes this reduction in pressure can be as much as 10%.

Shaking everything while charging will accelerate the blending process (or running the system for a bit can also do it). It just wasn't feasible in my situation to shake the whole unit. However I did shake the small transfer tank I used for the R123 and R22, and saw the pressure drop a good 40psi.

Also something worth mentioning; when I charge in the gases, I allow about 5 minutes to pass, and if I see the pressure drop, I top it up before moving on to the next gas in my charge list. Once again we are seeing a "soak-in" effect.

I hope that answers your question yngndrw :)

Ah I see, thanks for explaining that.

Nice improvement! That heavy Argon charge is paying off well :up: Would be really interesting to scale this up with about 2 to 3 times the capacity and try to use it on a processor. Could you use a larger system with a frequency modulator to adjust capacity? Would the autocascade eventually crash as you adjusted the compressor speed? Just thinking the lower stages might not enjoy the lowered massflow and I can't imagine using a ton of valves to adjust the capacity. Maybe a single solenoid on the evap feed to pulse refrigerant to maintain a temp but those solenoids aren't cheap.

-141,9 This merite respect!!!


solenoide? magnetic refregiration

Quote:

---

Nice improvement! That heavy Argon charge is paying off well Would be really interesting to scale this up with about 2 to 3 times the capacity and try to use it on a processor.

---

Yeah it's a big increase in Argon, but as you noted it seems to be working well, and the running pressures have remained very reasonable. The subcooler is definitely doing what it's supposed to.

Scaling it up for CPU usage would indeed be a great project. Unfortunately it wont be me to do it, since I am looking to scale it down (more of a repackaging effort, then a capacity reduction), and end up creating a production ready prototype. I think there is money to made in this arena, all it takes is finding the right industrial/laboratory/medical marketplace. And as you know, not too many people know how to produce reliable working autocascades, especially very small ones.

Quote:

---

Could you use a larger system with a frequency modulator to adjust capacity?

---

I don't see why not. In fact I think it would not only allow for excellent capacity adjustment, but also extend compressor life, by taking advantage of a ramp-up start-up ability.

Quote:

---

Would the autocascade eventually crash as you adjusted the compressor speed? Just thinking the lower stages might not enjoy the lowered massflow...

---

I wouldn't call it crash, but if run too slow, you would eventually run out of steam. And yes the first signs of this might be a disconnection between stages, as you get out of the optimum range of pressure vs. condensation point for a given refrigerant.

Quote:

---

I can't imagine using a ton of valves to adjust the capacity. Maybe a single solenoid on the evap feed to pulse refrigerant to maintain a temp but those solenoids aren't cheap.

---

Good point, and it could be made to work, but I suspect that the solenoid's life would be greatly reduced due to all the cycling required. Perhaps a better method would be to use an electrically controlled expansion valve. I think Sporlan offers something like this. And if coupled with a pwm output temperature controller, I think this would probably work quite well. It would simply replace the final captube.

Quote:

---

-141,9 This merite respect!!!

---

Thanks plasmatique :) Quoting Rodney Dangerfield "I get no respect". Well luckily this isn't true for me, although in my business it doesn't come easily either, so it's always appreciatted.

Quote:

---

Originally Posted by mytekcontrols

Quoting Rodney Dangerfield "I get no respect". Well luckily this isn't true for me, although in my business it doesn't come easily either, so it's always appreciatted.

---

Well on here there are a lot of people (Both builders and non-builders.) who have a great deal of respect for you and you deserve it. ;)

Good luck if you make a product out of your auto-cascades. :up:

Thank you Michael.

Maybe some scaling up would be a good idea if i were to find some decent parts ;)


A little OT on refrigerant soak in to the oil.

When i began to build phase change systems, when changing oil for the first time in a Danfoss SC10 i let all the oil out from the compressor through the suction line and a rubber pipe to a 2L glass. This was right after i discharged the system, well, when i lifted the glass and put it on my desk the shock from hitting it caused the oil to foam, all the refrigerant in it literally bursted forming a tall fountain. My PC, desk, walls, papers on it, everything within reach was all covered in mineral oil.

Looked very similar to a coca cola light + menthos experiment, or if anyone experimented with overheated water- dropping a single grain of salt in a cup of seriously overheated water.

It is sure, it ya a market for this type of product

I want etre inscribed on the waiting list for a central processing unit of treatment of this type...:)

I think you deserve to be an xtreme legend :-)

And remember kids for discharging refrigerant to atmospher you can be fined 25,000 dollars & stripped of your ticket and or jail time! Never mind the fact it is used in: Air dusters (R-134a & R-152a) Fire extinguishers FE-36!!!!

Mytek ever look into R-152a? As any and all computer air duster cans use it!

R-152a is "extremely flamable".

Quote:

---

Originally Posted by godmod

R-152a is "extremely flamable".

---

ya right only in liquid form, in gas form you can't get it to burn at all. and hardly extream either. It has been seriously considered for mobile systems here in Canada, but then again we use HC refrigerants in Mobile AC systems to so, take it as ye will.

Which pleasure of reading this file day apres day:)

Quote:

---

Mytek ever look into R-152a? As any and all computer air duster cans use it!

---

As godmod pointed out it is flammable, and this MSDS appears to be in agreement.

Although the boiling point is almost identical to R134a (-26C), I don't see any apparent advantage. Perhaps there is a COP improvement, but I haven't looked into this. Anyway this is probably a mute point, if one is trying to compose an autocascade refrigerant blend made up of nonflammable components.

However it could be useful in a HC charge blend, since I would guess that it would do well with conventional oils.

R152A appears to be ventable. (It is used to clean electronic components :) ) and one advantage is that it is misicible with mineral oil. it does wirk as R12 replacment but I am not sure about compatibility of material with the internal components of current and past compressors (shellac and or coating of the windings and seals and berings internal to the compressor. I have built a few systems with it and it works good as a single component refrigerant..


mytekcontrols
I have a block and kit for you to add to one of your systems if you want just give the word and I will ship it...

EDIT: Just finised catching up Great project and thanks for hte entire post here... Learned a lot abou autocascades...
I have a couple 1.5 HP Rotary horizontal's and a large selection of gasses.. ( Odd ones such as sulfer hex and iceon 89) if you want to play with the horz rotary I can also send you one of these...
First question.. have you used some of the new "Blends" (507, 89, 408,401) in autocascades.. ?

Quote:

---

I have a block and kit for you to add to one of your systems if you want just give the word and I will ship it...

---

Wow! Thanks chilly, that's a very generous offer, but I'll have to hold off until such time (if ever) that I get into cooling CPU's. My next project as I alluded to previously, will be a repackaging of the AC-2 with added features, and a more eco-friendly refrigerant charge. It wont be suitable for the higher loads required by modern day processors.

Quote:

---

I have a couple 1.5 HP Rotary horizontal's... if you want to play with the horz rotary I can also send you one of these...

---

I just might be interested; what's the voltage requirement and approximate dimensions on one of these? Make, Model?

Edit: Well after thinking about it for a minute, the voltage has got to be 220-240 VAC for a 1.5 HP compressor. Might still have a future application, but nothing in particular at the moment. So if I think of a serious endeavor for such a thing, and I think I'll have the time, I'll be sure to get back to you on this. In the meantime, can you send me a link to the specs, or give me the make and model info?

-Thanks

Quote:

---

have you used some of the new "Blends" (507, 89, 408,401) in autocascades.. ?

---

No I haven't, but if my memory serves me right, some of these use R125 as one of the components, as well as HCFC's which I am now trying to avoid.

I have done some experiments with R410a which also uses R125, and found it's high vapor pressure to be a problem (increases expansion tank requirements).

Chilly thanks for jumping into this thread. You are quite the legend on this forum, and many others :bows:

THanks. Well just thought you might get some inspiration having one of these olittle evaps and hold down kits setting on your shelf if nothing more than an interesting conversion piece... Ha ha just trying to see what insane machine you could get out of an evap designed for surface only cooling...
Compressor labling Wattage labling kinda got hit with oil got rough handeling getting here. 2000W/743W 115V MOdel QHR-11T Cap 50uF Lanhai Compressor company
I think it is a 743 watt motor so I think it might be only 1 hp which is about the size it is, however the company shipping it to me (Lanhai) said it was 1.5 hp but there is that Language barrier.... See I was trying to get some off the wall parts in your hands, I dont think you could let them set around without doing something off the wall with them... Haha ;) I also have a 70K @ 40 Watt cooler here (Fugger has the pump I got the head here) (1 Watt @ 4K)

Amazing thread, and knowledge here.
I have a source for instrument grade propane (R290) at 99.2% purity.
It is Scott medical gases here is the link
http://www.scottecatalog.com/Scottgas.nsf/web/MedHome
You will have to call for a quote. I purchased a case (12X 400gram cylinders) for $170
This is what we use in the cascades I work on.

Mytec: please check your web site email

Thanks.

ultralo1 welcome to XtremeSystems, and to this thread :welcome:

Also thanks for the lead on the propane, I'm sure several people around here will be most interested in getting there hands on some non camping stove R290 :)

Here is a more direct link to the propane info page on the site: medical grade propane

It's nice that they sell it in relatively small quantities (14 ounces), since it doesn't take much to charge up the systems being built around here, and It wouldn't be cheap if you had to buy 100 lbs of the stuff.

Although I never had given it the chance it deserved, I don't see why this in combination with some good quality butane, wouldn't work well for the liquid charge in the AC-2 unit.

Obviously I got your email, and it's cool that MG Pony pointed you in my direction. When everyone finds out what you do for a living, and the access you have to some very pro chilling equipment, as well as some exotic refrigerants, they'll be picking your brain in no time.

It's great to have another experienced person on board from this field of interest :up:

Quote:

---

Originally Posted by mytekcontrols

It's nice that they sell it in relatively small quantities (14 ounces), since it doesn't take much to charge up the systems being built around here, and It wouldn't be cheap if you had to buy 100 lbs of the stuff.

---

I use it in conjuntion with R23 mostly to aid in oil miscablity for the second stage. I usually charge from vacuum to 5psi with this. Then I will take R23 from 5psi to 65psi. This usually makes the unit reach -60 to -65c. Then I add a hose full at time to reach -85c which is design temp for the units.

i will explain the other use of it later when I have some time. We call it a "cold enema" :shocked:

Let me dig up my books on Auto cascades. I think they have the msds for the different refrigerants used by Queue in it.


Found it. No percentages or wieghts were given, proprietary.
R600a
R134a
R508b
R14
R740

When does that patent expire ? I rememember seeing one from polycold somewhere around 2000-2002.
It was before they where sold iirc.

Walt --- It's a fairly new patent:
Patent Number: 6502410
Co-Inventor: Oleg Podtchereniaev et al.
Patent Date: January 7th, 2003

So it wont expire until 2023.

Ultralo --- That Queue charge is very interesting. I'll have to think on it a bit when I get a chance tomorrow. Thanks for sharing it.

Quote:

---

Originally Posted by chilly1

THanks. Well just thought you might get some inspiration having one of these olittle evaps and hold down kits setting on your shelf if nothing more than an interesting conversion piece... Ha ha just trying to see what insane machine you could get out of an evap designed for surface only cooling...
Compressor labling Wattage labling kinda got hit with oil got rough handeling getting here. 2000W/743W 115V MOdel QHR-11T Cap 50uF Lanhai Compressor company
I think it is a 743 watt motor so I think it might be only 1 hp which is about the size it is, however the company shipping it to me (Lanhai) said it was 1.5 hp but there is that Language barrier.... See I was trying to get some off the wall parts in your hands, I dont think you could let them set around without doing something off the wall with them... Haha ;) I also have a 70K @ 40 Watt cooler here (Fugger has the pump I got the head here) (1 Watt @ 4K)

---

i personally didnt like their horizontal compressors chilly1, i bought 2 and the first one i tested died on me with limited use. So i stuck to using their normal rotarty compressors, they make a really mean csacade :)

Queue's Charge:

Quote:

---

Ultralo: Found it. No percentages or wieghts were given, proprietary.
R600a (BP = -12C)
R134a (BP = -26C)
R508b (BP = -88C)
R14 (BP = -128C)
R740 (not condensed)

---

The R508B is simply an HFC replacement for the formally used CFC-13 in standard cascades. It is composed of 30-50% HFC-23 and 50-70% HFC-116. I would think in an autocascade that R23 (BP = -84C) could be directly substituted, since the presence of the R14 in the blend would give you the colder temperature.

Ultralo -- is this charge being used in the Cryostar freezers?

Interesting note; Polycold licensed their technology to Queue in the early 80's. I was directly involved with creating the first prototype chest freezer designed for -100C operation. I also remember that there was a heat up problem after extended operation, due to oil freeze up in the final captube feeding the evaporator. The charge used at the time consisted of CFC-114, CFC-13, HFC-14, and Argon (R740). Oil return was solely done via the phase separators. I would imagine that using a charge with R600a probably would have solved the oil migration/freeze up problems.

I remember we even talked about using 2 final captubes with shut-off solenoid valves. And then cycling back-and-forth, thereby allowing one captube to thaw out while using the other.

Utralo -- On the subject of using hydrocarbons as refrigerants. At an early point in time, you mentioned something about propane being used as...

Quote:

---

Originally Posted by ultralo1

We call it a "cold enema" :shocked:

---

Are you ready to explain what and how this works? :)

Quote:

---

Originally Posted by mytekcontrols

Queue's Charge:


Ultralo -- is this charge being used in the Cryostar freezers?

---

Yes, this is the most current charge for -140 & -150. It is not cryostar anymore, it is now a division of ThermoFisher. They have bought all the major cascade players in the US. This division is based out of Asheville NC.

Quote:

---

[I]Interesting note; Polycold licensed their technology to Queue in the early 80's. I was directly involved with creating the first prototype chest freezer designed for -100C operation. I also remember that there was a heat up problem after extended operation, due to oil freeze up in the final captube feeding the evaporator. The charge used at the time consisted of CFC-114, CFC-13, HFC-14, and Argon (R740). Oil return was solely done via the phase separators. I would imagine that using a charge with R600a probably would have solved the oil migration/freeze up problems.

---

That what I love about the cascade industry. Its a small world. I still have a few of the old queue systems on campus. I usually let the my competitor handle these as he has been in the business for 20+ years. He handled them before we had a shop so his service notes are extinsve on these systems. i have been handling the newer systems, about 1 per year. There have been some major changes to the newer units. Scroll comps, double oil seps, larger condensors, buffer tank size, etc.

The COLD ENIMA, I had forgotten about that.
With the ULT -80s we have a problem with the users warming up the cabinet above -60c. When this happens the frozen oil in the evap becomes thawed. It is still highly viscous but mobile. The refrigerant flow causes this thawed oil to move. As it refreezes it will form "lumps" of oil which reduces the diameter of the evap tube thus refrigerant flow is reduced and capacity is reduced.

This is where the cold enima comes in at. The addition of 1-2oz of R290 into the 2nd stage system will disolve these "lumps" and allow the oil coating inside the evap lines to form a more smooth surface. This returns the flow back closer to normal and capacity increases. Although you dont usually get 100% capacity restoration. The design temp is -85c after enima it usually will only make -82 or -83c.

On a personal note I try to stay away from this method. This is because you have to put line taps on the system. It has been beat into my head that "ALL VALVES LEAK", and i have found this to be true to some exstint. Also you have to be very precise in the manifold, line purging when you do this or else you introduce a hose full of moist air into the sustion side of a system that is running in a vacuum. BAD JUJU.

What would be the best way to contact you privately?

I hope you don't mind me asking a question which is slightly off the current topic but is still very much related with auto cascades:

What is the general procedure for reclaiming / reusing blended refrigerants when testing different blends ?
Do you have to reclaim and then dispose of the charge each time, as it is blended ? Can you "distil" the different refrigerants out of the blend ?

Ultralo, thanks for the info. Very interesting and useful.

Check your email.

Quote:

---

What is the general procedure for reclaiming / reusing blended refrigerants when testing different blends ?
Do you have to reclaim and then dispose of the charge each time, as it is blended ? Can you "distil" the different refrigerants out of the blend ?

---

I use a standard recovery pump and evacuated tanks to remove the blended refrigerant. As for reclamation; sometimes I can use the recovered refrigerant as a "top-off" to bring a system's balance pressure back up to normal following a leak and subsequent repair.

It is also possible to distill out the liquid part of the charge by running it through a refrigerated vessel (cold trap) prior to entering the recovery pump, and also later when using a vacuum pump for final evacuation. Note: We are working on this.

If the conditions are consistent (fixed quantity of liquid in original charge, cold trap temperature, and ultimate vacuum level) then the recovered liquid's characteristics will also be consistent. So in other words, you'll end up with a liquid refrigerant blend which can be substituted for the individual components when making a new charge, but will require some adjustment in the proportions of some of the other components that make up the blend.

As for distilling out the individual components to their pure form; it would take some very fancy and expensive equipment to pull that one off. So from a practicality point of view, this is just not possible.

Whatever we can not recycle back into the units we service, does ultimately get picked up and disposed of by a refrigerant recovery company.

So in short you cannot fully separate the blend back into it's components, however you can "create" new blends by setting the temperature of the cold trap ? Does this not mean that you can set the cold trap to withdraw a blend which is very much like one of the components or am I misunderstanding this ?

Thanks for your explanation.

Yes it is possible to adjust what is reclaimed by the temperature of the cold trap. Although it'll never be 100% of any one of the refrigerants in the autocascade blend. There will always be some other refrigerant in partial solution with it.

Actually a technique I intend to try is just letting the cold trap run balls out at around -50 to -60C (no temperature regulation). Then recover the charge down to 10" Hg from a given unit into freshly evacuated recovery tanks with the cold trap in between (this also assumes that we start out with an empty cold trap). After wards; switch to a vacuum pump on the outlet of the cold trap, and allow it to pump the unit down to 500 microns or better (while using a crankcase heater on the compressor, and a heat lamp on the filter dryer).

Edit: To insure that the vacuum pump, when dropped to a low vacuum level at the end of the pump-down, doesn't begin sucking out the R22; it'll take an even lower cold trap temperature. This temperature would probably need to approach -100C or better, in order to keep the refrigerant condensed, and trapped.

When the low vacuum level has been achieved, store both the recovered gases and the liquid from the cold trap as a complete charge ready to be put back into a similar unit (liquids first into discharge, followed by gases into both the high and low side using a recovery pump in reverse).

Of course this assumes that the charge is something viable that can be reused. This procedure would work well when a very small leak needs to be repaired, or one wishes to modify the piping and/or captube flow rates, and just needs to temporarily remove the charge in order to do so.

Ah I see, that makes sense then. Thanks for that.

It seems that testing different blends in an auto-cascade is far from perfect due to the fact that you cannot accuratly reclaim the pure refrigerants, I guess that's a reason to go with a normal cascade if gasses are a problem for the builder.

Although I can't reveal the exact details on this project, never the less I thought you guys might like to see my new Heat Exchanger Stack aimed at producing -150C or colder.

The photo below shows the "layered" approach being used in this latest autocascade design, yielding over all dimensions of 10.5" high x 6.5" footprint. And of course there are all kinds of goodies stuffed down the center (no wasted space in this baby :up:).

Outer coil is 5/16" od inside of 1/2" od, inner coils are 3/16" od inside of 3/8" od.

The inner coil is broken in a few spots for insertion of tees (not visible -- on back side), and was wound in one operation following brazing of these parts.

The bullet strainer shown, is feeding both the final and subcooler captubes (yes the final part of the 3/8" coil winding is the subcooler).

Oh damn that looks nice and promising! Will you post the whole progress again?

Again, your work is amazing!!!!!

I think this will be his money maker so it would be fair for him to hold back, He shared more then any could have asked for in the first project!

Very nice work Michael, may I ask how heavy that stack is ?

Looks like it will be fun making sure that it's all insulated internally. (Between the coils.)

Yes Xeon, I completely agree! Michaels skills are so amazing, couldn't hold me back asking ;)

Quote:

---

Oh damn that looks nice and promising! Will you post the whole progress again?

---

No can do on this project, but I will post highlites from time to time.

Quote:

---

Very nice work Michael, may I ask how heavy that stack is ?

---

14.5 lbs

Must find your address and "borrow" that copper to resell ;) Looks like a ginormous stack, best of luck on that -150C goal, hope you crush it.

Quote:

---

Originally Posted by [XC] gomeler

hope you crush it.

---

If you can't "crush" the temperature, you can atleast crush it with the copper. ;)

Good luck.

My Base Pan arrived late last week, so I have begun the initial assembly phase.

Below are a few images of some of the main components bolted in place, and the De-Superheater/HXC connected between the compressor discharge and the condenser (I call this my Regenerative HXC, it'll be used to create an oil free Hot Gas source for Defrost).

The HXC Stack is just sitting on the base pan to show its basic area of residence, although in the final process it will be insulated from the pan.

The frame and HXC Stack insulation box utilize what is called T-Slot framing members for the main structural supports. The final assembly will use polycarbonate plastic sheets slid into the T-Slot channels, to create a box around the HXC Stack. And there will be aluminum panels bolted around the outer perimeter to form the unit's enclosure.

:up::shocked:
that will be a wonderfull news.

That's a really mean machine you're building there.

I love the heat exchangers, would you be willing to share with us the technique you use to coil them so neatly ? Or is it just the fact you're 50cm around the fore arm and 80 cm biceps ? ;)

When i made mine there was no way i could make them look as good as yours. Coiling them in a flat disc was the only option to make them look neat.

Curious, is that small condenser all you are using to dump heat from the system? If I gather correctly, you are using that looped 3/8" copper to separate the oil and that little capillary line coming out of it will be used for your hot-gas defroster. I take it you'll be depending on butane or a similar gas to dump massive amounts of heat through the condenser?

Michael - when i grow up i want to be just like you :up:
your work is great and i relly enjoy reading this thread
carl..

That surely is one hell of a stack :D Would a e.g. 10-plate HX we normally use in cascades cause too big pressure drop if used instead? Perhaps two 10-plate HXes if one intends to make single-stage autocascade (e.g. R123/R744)?

Amazing skills :)
Thanks for being here. I am learning from you.

@Berkut
One good way i used in the past for bending is to fill the pipe with thin sand,
like the one you can find in Greek beachs. :D

Quote:

---

Originally Posted by tiborrr

That surely is one hell of a stack :D Would a e.g. 10-plate HX we normally use in cascades cause too big pressure drop if used instead? Perhaps two 10-plate HXes if one intends to make single-stage autocascade (e.g. R123/R744)?

---

Plate HXs work just fine for autocascades. I plan on using plate HXs since I can't bend copper as neatly :up:

So in your opinion two 10-plate HXes will not cause too big pressure drop which could harm the performance?

Would two 6-plate HXes (if one could get a hand on them) be a better solution?

Quote:

---

Originally Posted by Unseen

@Berkut
One good way i used in the past for bending is to fill the pipe with thin sand,
like the one you can find in Greek beachs. :D

---

:rofl: not really?

Quote:

---

I love the heat exchangers, would you be willing to share with us the technique you use to coil them so neatly ? Or is it just the fact you're 50cm around the fore arm and 80 cm biceps ?

---

I do have Popeye arms. Probably from all the years of bending tubing with my bare hands. As for how do I coil the tubing so neatly; it literally is because of many years of experience, and having created quite a few HXC designs. But I'll let you in on a trick. It is very... very important to fix the starting end of the coil wind to the mandrel that you are using to wind it on (fire extinguisher in my case for the outer coil, and large filter dryer for the inner ones). If you let this end slip, then the coil will both grow in diameter as it is wound, and it will most likely kink as well. Also when winding; try to come close to overlapping the previous turn, and let it roll off to the side of it. This will keep the coils tight together.

Quote:

---

Curious, is that small condenser all you are using to dump heat from the system? If I gather correctly, you are using that looped 3/8" copper to separate the oil and that little capillary line coming out of it will be used for your hot-gas defroster. I take it you'll be depending on butane or a similar gas to dump massive amounts of heat through the condenser?

---

Chris, I am gambling that the condenser will be enough for what I am doing. I am also counting on the nature of the refrigerant blend in the autocascade to do a much better job of heat rejection vs. a single stage system (and yes there will be some butane in the mix).

Edit: For extra cooling, I can always add another fan on the opposite side of the compressor if need be.

The looped superheater is not for oil separation, but it is a HXC for creating hot gas from a cold gas source, that being gas taken from one of the downstream phase separation points. And it also serves as a vibration eliminator.

Quote:

---

Michael - when i grow up i want to be just like you

---

Thanks carl. Perhaps when I do grow up, I'll be like me also :D

Quote:

---

That surely is one hell of a stack Would a e.g. 10-plate HX we normally use in cascades cause too big pressure drop if used instead? Perhaps two 10-plate HXes if one intends to make single-stage autocascade (e.g. R123/R744)?

---

I agree with Chris's response to this question. Actually the plate heat exchangers probably have a little less pressure drop then my stack, and would work even better due to their extended internal surface area.

But as you can see, I didn't have a lot of room to play with in my new design, and using plates would have required much more than what I was willing to allocate. Also believe it or not, my HXC Stack design was very easy to build, and only took me 3 hours from start to finish.

Edit: Even though the pictures show extra space at present; by the time I am done with this build, there won't be hardly any unused areas left (the area above the condenser will be for electrical control, valves and instrumentation, and the space to the right of the expansion tank will be occupied by dual insulated cryo feed-thrus

Quote:

---

Amazing skills
Thanks for being here. I am learning from you.

---

Thanks unseen :)

Thanks for the explanation, mytek, two plate HXes for me it is then! :)

You are doing fantastic job, keep it up! P.S.: In case your condensor wouldn't suffice, you can always stack another one on top of it.

Continuance in the exellence :)

Just a little longer, and I should have some more pics to post :)

Been side-tracked while working on new load controller product.

Ok here are some images of what I call the Cryo-Feed-Thru. It facilitates getting the final stage Feed and Return out from my insulated HXC box, into some real world connections (Swagelok VCR's). The inside of the stainless tube will be polyurethane foam insulated (same as HXC box), and a special saddle clamp (not shown) will be used to secure it to my Tslot frame.

I can only take credit for the silver solder work on the inside of the cap. A friend of mine at the place I contract to, did the excellent tig welding of the cap to the tube.

I should have more pics of the Feed-Thru being used in the complete assembly within the next week. I'll be sure to post them.

I love the idea of "Morphing Air Conditioner into Autocascade System ", i have a stand up, rolling airconditioner that i am gonna take apart and see what we got,

thanks so much for all the info you posted, It has given me a wake u call to get rocking, my outside air/antifreeze set up will be warming up in the next 2 moth and i need a new snow maker.

Top notch work and mucho respect :up:

Hey Michael, your new auto cascade is awesome! I have yet a question on your old one regarding the configuration of the high pressure cut out switches (the one for the exp tank/buffer valve and the other one as saftey device #2):

You wrote that you set the "Compressor High Pressure Cut-Out" to 400psi cut out and 300psi cut in. Du you think the compressor will start again? I think the compressors overload protection will "click". Did you think about using a relais to combine it with the buffer valve control switch to let them open both (to make sure the compressor CAN start again)?

next Q: have you put steel/copper wool inside the phase seperator #1?

edit:

Quote:

---

Originally Posted by mytekcontrols

I should have more pics of the Feed-Thru being used in the complete assembly within the next week. I'll be sure to post them.

---

it's next week, so we're waitin' for the pix :fact:

Very impressive. :)