CO2 Cascade project: "Black Ice"? (hope thats original....)

[stockhatch]

Ok, so I have finally gathered enough parts to start a worklog of my cascade.
Parts list is as follows:

Mastu 1hp compressor for 1st stage
7700btu Toshiba compressor for 2nd stage
2x Singer/Eaton CPEVS for stage I and II
condenser snagged from 7700btu window unit
15' 1/4" in 1/2" IHX
6 row chilly1 condenser for 2nd stage desuperheater

Today I made a little bit of progress. Stage I is mocked up and pretty much ready to braze once I get a site glass. This will just be a test run for the 1st stage, so some piping may change a little bit in the future. I put some casters under the platform, but I'm considering buying a sheet of pressboard as it is more rigid than this 3/4 plywood. Plus it will take paint smoother.
http://img.photobucket.com/albums/v46/stockhatch/stage_I.jpg It will be tight getting the fan in there, but it is doable. I measured it to be sure. I wanted all the lines and components far enough away from the IHX to allow for some decent insulation.

EDIT: Good news, the 1hp compressor still runs :D I picked up a cap for it today and tested it. Figured I didnt want to go through all the work of brazing, and vacuuming just to find out its fried.

[Marvin]

nice and clean job. keep us posted. :toast:

[MutantToad]

Looks nice. You made the desuperheater and IHX yourself? Keep us updated!

~toad

P.S. Purple Ice is more original than Black Ice. ;)

[chilly1]

Ok, so I have finally gathered enough parts to start a worklog of my cascade.
Parts list is as follows:

Mastu 1hp compressor for 1st stage
7700btu Toshiba compressor for 2nd stage
2x Singer/Eaton CPEVS for stage I and II
condenser snagged from 7700btu window unit
15' 1/4" in 1/2" IHX

Today I made a little bit of progress. Stage I is mocked up and pretty much ready to braze once I get a site glass. This will just be a test run for the 1st stage, so some piping may change a little bit in the future. I put some casters under the platform, but I'm considering buying a sheet of pressboard as it is more rigid than this 3/4 plywood. Plus it will take paint smoother.
http://img.photobucket.com/albums/v46/stockhatch/stage_I.jpg It will be tight getting the fan in there, but it is doable. I measured it to be sure. I wanted all the lines and components far enough away from the IHX to allow for some decent insulation.

EDIT: Good news, the 1hp compressor still runs :D I picked up a cap for it today and tested it. Figured I didnt want to go through all the work of brazing, and vacuuming just to find out its fried.
Looks good.. can't wait to see some scores...

[stockhatch]

Thanks for the comments :) MutantToad, I made the IHX, but which desuperheater were you referring to? If you mean the coil after the compressor, yes I made that. If you mean the little 6 row condenser, then no ;) Does anyone with some cascade experience think its worth the plumbing difficulty and space to use a suction line HX in the 1st stage?

Thanks

[kayl]

hmmm i dont think so, i have troble flooding first stage coil hxs, keeping the -40c in and out it difficult.
second stage yes though, with the accumulators its easy to flood second stage right back to the compressor.

[fatty]

What oil do you need for co2?? also what is the best temp for the first stage to be at befor you run the second stage co2??
Cheers as I am trying to get a cascade together and just found some co2 cheap I have 134a or 507 for the first stage

[Cossey]

stockhatch: nice and neat.

Fatty: normally most ppl mix somethingelse in with the co2 for oil carrying, 290 works well for mineral oil or you could use 507 with poe. use the 507 for the first stage, better temps will make it easier to condense enough co2 for decent capacity on the second stage.

[hatemi]

Fatty:

Good first stage temps are essential so use 507 :)
for second stage I would try it with r507+co2 first. It might be better to use propane in the second stage or a mix of all gases. Getting the second stage to hold temps with CO2 is just PITA.

[Tonic]

Good start, I'm waiting :D

[stockhatch]

hmmm i dont think so, i have troble flooding first stage coil hxs, keeping the -40c in and out it difficult.
second stage yes though, with the accumulators its easy to flood second stage right back to the compressor.

So you would recommend a suction line HX on the 2nd stage? Just want to make sure I'm reading your reply correctly...

[_HL4E_HalfLife_]

402A on 1st stage is also very common here. The only thing is this gas needs either AB oil or POE oil. AB is at the top of the list for 402A.

[Waus-mod]

great start:) looking forward!

[stockhatch]

Got the 1st stage brazed up, vacuumed and started messing with it tonight. Best temps I saw were -36 HX in unloaded. Its not too great, but I will mess with it some tomorrow. Im also charging it blind due to not having a site glass yet. I am basically just testing it to see how it will behave and to clean it out. Once I run it for a while I will buy another filter and braze it in along with a site glass. Then I can really start tuning it. http://img.photobucket.com/albums/v46/stockhatch/stage_I_test.jpg

[fatty]

That looks great I think I might need a bigger compressor for my first stage looking at that either that or I need to tune it a hell of a lot better great work

[stockhatch]

I messed with it a bit today and the best temps I saw were -40.3 HX in, -34.3 HX out. These are unloaded temps, but I have zero insulation, so I do expect them to get a little bit better. I cant get superheat down to where it needs to be. The HX is either flooded with high temps ~-20, or its getting good temps with really high superheat. Will this all change once I load it?

[stockhatch]

Actually, I need to be measuring superheat just after the HX dont I? I was measuring it at the compressor inlet.

[Cossey]

measure it 6 inches from the compressor

[wdrzal]

If you measure to close to the compressor you will read the heat from the compressor that migrates down the copper tube by conduction.

[masterofpuppets]

Lookin' good. Take more photos :woot:

[stockhatch]

So where do I need to be measuring it? Most ppl put the sense bulb for their TXVs right after the HX, so they are tuning with HX superheat, not total superheat. Also, is it even worth the trouble to tune with superheat unloaded? Superheat will climb once I do load it so I'll have to tune it again right? Then again, I always hear "tune the 1st stage till its perfect before you even try to run the 2nd stage". How do I proceed?

Thanks

[stockhatch]

Then again, with no insulation, I would say I have a pretty decent load on it as it is. Not what the 2nd stage would put on it, but Im pulling in all sorts of heat from the air.

[Waus-mod]

nice work stockhatch! happy tuning

[stockhatch]

Thanks! :) Looks like its going to take ALOT of tuning :D

[stockhatch]

Latest results are ~-38 in ~-35 out. I am going to call this good and go ahead and insulate the IHX. Hopefully the HVAC store has some bead probes I can attach before I close the HX up so I can measure insulated temps.

http://img.photobucket.com/albums/v46/stockhatch/tuning_stage_I.jpg

My condenser fan is crap, so I am using the shop fan until I can find a replacement :D

[GuGaCoSa]

Man,your vacuum pump will do a hard job taking out all the moisture you created in the 1/4 pipe inside your HX,i think u should close ends and pull a vacuum before freezing all up,but i'm sure u know what your doing,just my 2 cents =~]
BTW,very nice system and piping,loved it.

[stockhatch]

LOL its funny you mention that. I was just roughing in the second stage when I looked at the water dripping from the 1/4" pipe in the IHX. I thought "SOB!" I am going to braze a shrader on one end and braze the other shut and pull a good long vacuum on it before I even attempt to braze anything for the second stage.

[stockhatch]

Ok, little update here. i have all that I need to finish this now with the exception of CO2 and the regulator to get it in the system. I decided to rebuild the base using MDF, and love the way it is turning out. i still need to build my control console, but here is the painted base, and assembled IHX box. http://img.photobucket.com/albums/v46/stockhatch/new_base.jpg
The IHX inside:
http://img.photobucket.com/albums/v46/stockhatch/new_base_2.jpg
Here are the holes for my two IHX probes:
http://img.photobucket.com/albums/v46/stockhatch/probe_holes.jpg
Here it is all test fitted:
http://img.photobucket.com/albums/v46/stockhatch/base_probes.jpg

BTW, I bought three K type probes for $9.00 each from Johnstones. Have they come down? I was thinking they were more than that normally. Not that I am complaining :)

More updates to come!

[_HL4E_HalfLife_]

Do what i did for charging the system with co2 put the tank in a chest freezer for a few hours to bring the pressure down to safe gauge hose pressures and use a Bullet piercing valve to regulate the flow into ur gauges. It works great for me


3 WORDS: Cheap and Effective!!

[stockhatch]

Interesting idea, but I think I am just going to buy a CO2 regulator :)

[Waus-mod]

Sweet hx box you made there.. this is gonna get pretty!

[kayl]

looks good.
Have you got some white foam to put in there
save on the expanda foam
ya will need a few cans

[chilly1]

402A on 1st stage is also very common here. The only thing is this gas needs either AB oil or POE oil. AB is at the top of the list for 402A.
R402 will work with mineral oil due to its R290 content...

[chilly1]

Actually the PEV on the system will nor give it a stable superheat. You need to tune it with the system insulated and you will need to Put a TXV on it.
FOr superheat (Basically a representation of teh delta across the evap. ) SO the higher the superheat the higher Entering suction temp of the compressor and the hotter it runs, For example a system tuned best loaded temps with too small a metering device for the compressor used will have a high superheat. This will cause the compressor to run hot and may cause overheating. SO we try to tune for a superheat that will allow the compressor to run within normal parameters. Freezer compressors sometimes are rated to be able to handle up to a 20 degF of superheat, this means that thins compressor is able to handle a higher temperature then one that will onld do say 10 to 12 degF superheat. Too high superheat is a common cause of premature compressor failure.
So if you use a PVE make sure to monitor your compressor discharge temperature and keep it under 220 F

[stockhatch]

Actually the PEV on the system will nor give it a stable superheat. You need to tune it with the system insulated and you will need to Put a TXV on it.
FOr superheat (Basically a representation of teh delta across the evap. ) SO the higher the superheat the higher Entering suction temp of the compressor and the hotter it runs, For example a system tuned best loaded temps with too small a metering device for the compressor used will have a high superheat. This will cause the compressor to run hot and may cause overheating. SO we try to tune for a superheat that will allow the compressor to run within normal parameters. Freezer compressors sometimes are rated to be able to handle up to a 20 degF of superheat, this means that thins compressor is able to handle a higher temperature then one that will onld do say 10 to 12 degF superheat. Too high superheat is a common cause of premature compressor failure.
So if you use a PVE make sure to monitor your compressor discharge temperature and keep it under 220 F


Will do on the monitoring :) So you dont think the PEV will work on the 1st stage at all? I can get the superheat within range I think, but my IHX temps will suffer :( If I do go ahead and spring for a TXV on the 1st stage, do you think this PEV would work well on the 2nd? I guess I will try to get superheat under control with some insulation and see how the IHX temps end up. If they aren't satisfactory then I will opt for the TXV.

Thanks to all for the help and comments :toast:

EDIT: Duh, I know what you mean now. The PEV wont keep superheat from fluctuating because it does not open and close according to superheat, it opens and closes as a result of pressure. This isn't necessarily a bad thing, it just means that I will have to tune for correct superheat under a load.

[stockhatch]

Ok, a couple little updates today. I have built the control console, so I just have to figure out what gauges, lights and switches I want to stick in there, cut holes, and wire it. Here are some unpainted pics of it. Some of the edges are not razor sharp, but I am going to sand, prime and paint it until its perfect. I'm just anal like that :D
http://img.photobucket.com/albums/v46/stockhatch/console_front.jpg
http://img.photobucket.com/albums/v46/stockhatch/console_angle.jpg
http://img.photobucket.com/albums/v46/stockhatch/console_rear.jpg

[hatemi]

I would say your making the damn box look too neat :D

[stockhatch]

I would say your making the damn box look too neat :D

LOL Yeah, true. Whenever I make something that LOOKS good, it never works :D

[Dementor]

LOL Yeah, true. Whenever I make something that LOOKS good, it never works :D

LOL! Everything is looking great so far man. Just keep up the good work and try not to rush it. Remember, everyone is always here to help :) :slap:

[_HL4E_HalfLife_]

R402 will work with mineral oil due to its R290 content...

I still wouldn't use MO chilly1 because 402A only has 2% propane the rest of it is 38% R22 and 60% R125. The companys the sell 402A say that it is only safe to use MO if the distance between the compressor and the evap is less than 1.5 meters AND if the evap is within 4feet of being the same hight as the compressor.

[stockhatch]

Okay. I have finished with the painting for now. I'm going to call it good enough for now and start reassembling.
http://img.photobucket.com/albums/v46/stockhatch/base_painted.jpg

Try to ignore the transport inflicted scratch up on the console. Frickin thing got scratched pretty good when I was moving it.

I also made a logo for the project :D Im going to print some decals with this once everything else is wrapped up. (assuming I actually hit -100C LOL)

http://img.photobucket.com/albums/v46/stockhatch/black_ice_logo.jpg

[stockhatch]

Here is stage 1 reassembled on the new base. http://img.photobucket.com/albums/v46/stockhatch/stage_1_front.jpg

[SlackeR]

Looking very nice so far. I like the idea of a real control console for all the meters and switches. Un-ghetto cascades rock. Ghetto cascades rock in a different way :D

[stockhatch]

Thanks :) There is one problem though...this sucker is getting HEAVY!! :D Too much more assembly and I wont be able to move it.

[Bloody_Sorcerer]

put it up on casters. isn't that what most people do?

[stockhatch]

I was going to, but I think I will make it a table queen instead. Im going to buy a table just for it, as the top of the IHX box was cut specifically to fit a motherboard. I can bench right on top of the cascade itself :)

[Comp-Freak]

Very nice, keep on going :clap:

[Gray Mole]

Jeez if your Cascade works as good as it looks, you'll be getting ppl bugging you to make 'em for them, hope you're ready for it! :D

Seriously though, that's a really good looking setup mate, looks like you've really thought out this build :toast:

Gray

[masterofpuppets]

Nice work.

[SlackeR]

Thanks :) There is one problem though...this sucker is getting HEAVY!! :D Too much more assembly and I wont be able to move it.

Well they do ;)
You have to get a table with some wheels i guess. And get it on that table before you add more stuff unless you have a forklift :p:

[stockhatch]

Thanks for all the nice comments guys :) Today I am working on the 2nd stage piping. Here is the desuperheater plumbed into the IHX.

http://img.photobucket.com/albums/v46/stockhatch/desuper_1.jpg
http://img.photobucket.com/albums/v46/stockhatch/desuper_2.jpg

[stockhatch]

I put pressure on the IHX and leak tested it one more time and then taped my probes on and sprayed the insulation. Hopefully its all good, because getting to it from now on will be a pain :D I ran out of the insulation, but here it is so far.

http://img.photobucket.com/albums/v46/stockhatch/insulated_ihx.jpg

[kayl]

very nice, how big a can of expanda foam did you use to all do that.

[the_new_guy]

I put pressure on the IHX and leak tested it one more time and then taped my probes on and sprayed the insulation. Hopefully its all good, because getting to it from now on will be a pain :D I ran out of the insulation, but here it is so far.

http://img.photobucket.com/albums/v46/stockhatch/insulated_ihx.jpg

this is pu foam right

[Jort]

yes it is, i de hope so you don't have any leaks:D

[stockhatch]

very nice, how big a can of expanda foam did you use to all do that.

Just over 3 cans finished it. The first pic is after 3. Here it is finished and trimmed :) Not positive what type of faom it is, just that its called "Great Stuff"

http://img.photobucket.com/albums/v46/stockhatch/insulated_ihx_done.jpg

[Marvin]

nice insulation.
go and keep us with news.

[Coyote]

really neat, nice looking unit.

i hope it performs as good as it looks ;)

[_HL4E_HalfLife_]

EWWW BRAINS!!!!!

lol but no i use Great Stuff as well :p:

[SlackeR]

Just over 3 cans finished it. The first pic is after 3. Here it is finished and trimmed :) Not positive what type of faom it is, just that its called "Great Stuff"

http://img.photobucket.com/albums/v46/stockhatch/insulated_ihx_done.jpg


hehe that is the greatest name it could ever have :D
It is the best. After Ducttape and zipties.
And yes, it is PU-foam. don't get it on clothing. It won't ever come off.

[gkiing]

Looking good :D

Especially the insulation on your hx. And by the way, on the PU foam can it will say "Must be removed mechanically" :P

[runmc]

I would get a txv for first stage and save that pev for second stage. Your superheat will be going up and down as load changes. When you turn the first stage on your load will be constantly changing as your IHX cools. Then once you have the pev adjusted for that temp, it will change again when you turn on second stage and then again when you turn on your PC. The txv can adjust itself for this change and the pev can't. You will have a nightmare trying to tune the first stage once you have it all together. I can understand you wanting to give it a try though. :D

Your doing a top notch job :woot:

[Tonic]

I would get a txv for first stage and save that pev for second stage. Your superheat will be going up and down as load changes. When you turn the first stage on your load will be constantly changing as your IHX cools. Then once you have the pev adjusted for that temp, it will change again when you turn on second stage and then again when you turn on your PC. The txv can adjust itself for this change and the pev can't. You will have a nightmare trying to tune the first stage once you have it all together. I can understand you wanting to give it a try though. :D



I would do a polemic with opinion about TXV. What we want in cascades, is the most low and stable
evaporator temperature.

With changing heat loads you're right, Ron, but that's not issue, PEV can give the same final temperatures
(when both stages and PC are turned on). The differents between TXV and PEV on first stage should be
a speed of decreasing temperature - TXV, thanks to its sense bulb, constantly operate nozzle
when heat loads are changing and that's why it gives faster temperature dropping than PEV.

With PEV you calibrate in that way :

1). Tune first stage to most low temperature with PEV
2). Turn on second stage
3). Tune second stage with PEV
4). Tune first stage with
5). Optional, tune again second stage
6). Turn on PC
7). And under evaporator load again tune both stages, one, then second, one, then second etc. until you will get the best temperatures

And finally you have set properly PEVs, they will constantly feed a amount of liquid refrigerant and give
the best temperatures with both stages and PC working.

I would rather to say that choosing PEV or TXV depends on that what we want, fast temperature
dropping, method to calibrate, prices and other conditions ;)

[stockhatch]

I bought three PEVs for ~$7.00 each, so I think I will try them out. As Tonic mentioned, they should give the same temps in the long run, just it will take some manual tweaking. If I run across some extra cash I may get a TXV just for faster pulldown. It will be a bolt in deal being that I am already using flares. Thanks all for the comments and suggestions :)

[giorgioprimo]

signed

[Think]

nice :)

[Cpt Twitchy]

i have a rather horrible story about "great stuff" If you want to know ask. But heres a hint it is really sticky when on skin.

[Tonic]

i have a rather horrible story about "great stuff" If you want to know ask. But heres a hint it is really sticky when on skin.

I confirm it - once time I was filling insulation box for chiller with this foam. Of course, because of my lack of experience,
I had both my hands covered by this foam. That was PITA, it took 4-5 days scratching this foam out of my skin :p:

[the_new_guy]

ooch!
do you know where i am likely to get it in india?

thanks

[Fast]

signed:D very good joob,I have not noticed a separator of the oil... you will use it?

[Tyrou]

on a dual stage, an oil sep is needed on the second one ;)

[stockhatch]

Already have that covered. I brazed a sep up, but I didnt use a shield gas, so Im not happy with the amount of crap inside it. I am going to braze another with a shield gas. Plus I want to bring the tubes in and out of it in a diferent direction than the original.

http://img.photobucket.com/albums/v46/stockhatch/sep_parts.jpg
http://img.photobucket.com/albums/v46/stockhatch/sep_finish.jpg

I don't have receivers either. I think the 1st stage wont need one because of the huge condenser, but the 2nd will prolly need one, so I will end up making a small one for it.

[stockhatch]

Progress!. I have been at a standstill on this project because of lack of parts, but now pretty much everything is in and Im ready to finish it. Here is the new oil sep brazed up and in the loop as well as the suction line HX. I got my gauges in as well. More pics to come :)

http://img.photobucket.com/albums/v46/stockhatch/progress.jpg

[the_new_guy]

cool man!! hope to see temps soon!
any thing major left?

[stockhatch]

Evap, suction line, gauges and wiring. I need to find a decent fan and build a shroud too. Geeze, when I sit down and list it all, it sounds like alot :D

[the_new_guy]

hey how is that eaton cpev, any good?

[chilly1]

Hey my metal guy can pop out schrouds like crazy ,, I am ordering a few tomorrow PM me and I will get it done for ya.. need Hole dimentiona dn square opening..

PAy close attention to teh eaton CPEV's at low temp I have had a few leak after the first few runs.... The epoxy holding the head on leaks..

[Frambosie]

wow! that looks great, im very impressed with the overall sleekness and compactness of he setup! :toast:

[stockhatch]

Hey my metal guy can pop out schrouds like crazy ,, I am ordering a few tomorrow PM me and I will get it done for ya.. need Hole dimentiona dn square opening..

PAy close attention to teh eaton CPEV's at low temp I have had a few leak after the first few runs.... The epoxy holding the head on leaks..

Sweet :) As always thanks for the help. I'll keep and eye out for leaks. If it does leak I may stop being so cheap and replace the 1st stage with a TXV :D So far it appears to work pretty well. It's cool to be able to crank it as the system runs and watch the frost line run hehe.

[stockhatch]

More progress. Guages are fitted though not hooked up. Progress is slow as I dont have alot of energy after work... If it ever stops raining I'll go ahead and braze the rest of the second stage together. Stay tuned.

http://img.photobucket.com/albums/v46/stockhatch/gauges.jpg

http://img.photobucket.com/albums/v46/stockhatch/gauges_close.jpg

[Waus-mod]

pretty cascade for sure :D

[the_new_guy]

:clap:

[RussC]

Sweeet,
Look forward to the results.

RussC

[MeltedDuron]

wow... purdy cascade :)

[stockhatch]

Okay. A little update. Today I brazed in all of the second stage that I could. I am missing the flexible suction still, but the high side is pretty much ready. I sealed up stage II, pulled a vac on it and charged stage I again. The IHX gets down to temp much better since it is insulated. It hits ~-42 in ~-43 out with ease. I think once I do the final tune it should have no prob condensing the second stage.

[Think]

hows your project coming along...it's been awhile and was curious.

[quintus]

stockhatch
Xtreme Member
Last Activity: 08-20-2008 11:45 PM
...

[SexyMF]

hows your project coming along...it's been awhile and was curious.

You can't argue with that. Somewhat understated, but true none the less.

[cooling storm]

you opend a fourm that was last aktive 10-29-2005, 09:15 PM