New Cascade on the way

[Gray Mole]

Well my lovely wife stole the lead for my camera or I'd have something to show you guys, but as I was done all that Mach mods for now, I thought I'd get back to work.

I bought a lot of Rotary compressors, 3/4HP, and thought I'd give 'em a test. Someone else around here should be getting a pair of 'em very soon so maybe some more action will be coming too.

At the moment I'm vaccing out the second stage, and after it's vacced it'll get a new filter again, as I'm a little more paranoid about that these days, but I got to test the High/Base stage already.

Before I get into temps, I just want to say that these Rotaries run hot. I mean seriously, 'cook an egg while you bench' hot. The thermal protection is at 150c. That's how hot they can run, and with no load and just the first stage running it was very close to 100c on the side of the compressor.

Anyways, the good news is the vacuum they can pull. I charged it with 404a, and a small bit of R290 cos they're R22 compressors and so have mineral oil, and 404a doesn't carry it. I got to about 145 to 150psi high, running into 15+ inHG low, frosting through the suction line heat exchanger, and reasonably close to the accumulator that's strapped to the compressor.

It was pulling -68 or so on the heat exchanger, fully frosted. I'm not 100% insulated yet, but that's so amazing.

Anyways, I know it's just a tease, but I'll have pics very soon, and if all goes well tomorrow, I can get the second stage clean and charge it up. I'd like to see temps more like -80 load rather than the -75 I had before but we'll just have to see...

Gray

 

[fatty]

You old tease you so when am I getting my two

all I want for xmas is my two rotarty's yes my two rotary's :O

C'mon Mrs Grey give the lead back

 

[boardy]

oooo Gray's tempting me with another cascade thread!!

Must resist the temptation to buy one, must resist!!

Show us pics, PLEEEEEEASE. Fatty I wanna see more cascades from you, lets have a little competition, who can make the best cascade lol. (wow I'm tired :S)

 

[fatty]

Ummm hands down on the cascade that will be Grey he got the gass me I will just build a nice humble -80 or so

 

[Gray Mole]

LOL with these compressor's Fatty you will have power beyond your wildest dreams if things go my way you'l either be getting 'em shipped today or tomorrow at the latest, so your Xmas wishes should be coming true. :B

Certainly not a 'silent' cooling solution, but very cold. My wife's promised to bring the lead home today from her work, so I'll get pics taken of it, and temp shots and all that ready.

I went with a quick 'open plan' this time again, mainly because if there's any problems things are fairly accessable. The Low stage filter is a little further from the HX to try to make sure that temps aren't an issue as the filter's are only meant to be good to -50 or so.

I'ts still compact enough to 'black box' it if it works as it should.

I just used a run cap and no start cap with the compressors and it's fine, but I did notice that if the thing's not balanced it doesn't want to start, so I might just dig up a start cap and relay for it so that's not an issue. You still need to give it a 'restart delay' much like you would a Mach2, but a start cap would make that delay much reduced. Starting from cold is perfect, and as long as the pressures are within about 20psi of each other it's also fine.

I used a 6' captube on the high stage this time, and hence the HX takes it's time getting fully frosted, so I might consider changing that to one of the TEV's I've got here as long as the Low stage works fine, shoudl sped up the pull down, but captube is more consistent, as there's no 'moving parts' and all that, but I've got a feeling that the result would be nicer going to TEV.

The Low is 2.1m of .031" so it should come down to temp quickly and have a very good capacity to it, 220w+ I would imagine.

We'll see how it goes today, I'll be vaccing over the day, since the pressure test was ok on the low stage so if all goes well, I might see some uber-cold action tonight

Gray

 

[Marvt74]

Sounds nice, i'm still waiting for you to get back to benching with all these cascades dude.

Did you ever break 40k?

 

[maverik-sg1]

Gray can you fir a cascade in a mach footprint? Height not important but be nice to still slot one in under me Lian Li Case?

Or could it owrk around a mountain mods Footprint?

Loads of projects ongoing in mavs head right now - not sure how to proceed.

 

[Gray Mole]

Funny I never did break 40k. I broke a lot of hardware in the process, but never got it. By the time I get a benching rig back together the new gear should make it easy though I suppose. Finding the same stuff I had before and trying to 'recreate' the same challenge would be interesting though...

Hey mav, to be honest I think that if a person 'gutted out' a full size mountain mods case for the cascade, and had a matching one on top, then a small cascade in that setup would fit just fine. It would be a squeeze for good size compressors but the end result would look pretty sweet.

At that point the real challenge is doing up a kit that would take teh condensation issues away, but using a backplate heater and another 'vapo-style' surrounding heater for the socket side as well you might be able to run a cascade safely in a case. It would still hit you in the electricity bill tho

A pair of decent 1/2HP compressor's would fit in one of those cases I think though, and it would just be a matter of fitting everything around it, but should be easily doable. Not a small MM case though, would have to be the bigger version, though I can't remember what the smaller one was called, Twi-7 or something is the smaller one?

That would actually make for a really nice looking cascade box...I might just have to see if I can't find an old used one for a reasonable price and cut it up a bit and see how things would fit.

Gray

 

[boardy]

/run from mavs nutterness! If you get this done mav, I will actually come and see it in person, I'll just show up and demand to see it!!

That would be such an awsome looking machine. Hmm *counts pennies and then cries*

 

[scorchio]

Boardy you need to calm down you are going to have a heart attack.LOL must admit it does sound a great idea.

I just know i'm going to get one at some stage i just wish you could run them 24/7.

We need pics Grey me old pal and a bank loan!!

 

[boardy]

hehe, heart attack at my age, bah

 

[fatty]

Grey hold the compressors just now need to have a quick chat:O

 

[Gray Mole]

NP Fats, we'll see how this cascade fares, and maybe I'll end up using them all

Anyways, had a similar blockage to some of the other issues I've had so I'm going to switch form the solid core filter's I've been using to the spun copper type and recharge the second stage.

I did manage to get it running for a while, and it was holding the load tester at -80 or so, so these rotaries are really showing their potential.

When it just started to block it wouldn't hold the load anymore, and I let come down to the lowest temp that it would go to with it restricting the flow of refrigerant, and I got to see -117 on the Fluke. No way that would hold any load at all, but pretty cool anyways.

I've really got to get to the supplier's to pick some stuff up in the next day or so, and will get some new filters while I'm there. Small delay on any real results, but will give me some time to get a little bit of insulating done too.

Pics when I can

Gray

 

[Gray Mole]

Good news, Bad news

Well let's start with the bad news...

I had a problem with one of the bottles of R23, the valve wouldn't shut properly and it slowly seeped out. I didn't realise, so that put me to only the one bottle. Was quite a while ago, but I knew that it would catch up with me.

With all the problems I had with the cascades, I ended up with a lot of waste, and it went into a spare dumpy bottle, what I could get out as it's not easy to recover R23, and it's mixed up with some other gasses I thought might have contaminants.

So, I'm all out of gas, as it were 8) I've still got 402a and 404a, and soon I'll be adding some 507 to the list, and I'm hoping that either isceon89 or 410 might join that list too, but we'll see. It's the Cascade gas I don't have atm, so cascadin will have to be put on hold until funds are there to do more. Won't be too terribly long, and I should have a choice of R23 or 1150 for the next gas purchase, but it'll be a little while.

Geez, is there any good news?

Well, I think I've got my blockage problems sorted out. On my first cascade (yes, it was a little messy) I didn't get any blockages. No real problems other than the base stage compressor got some serious start issues and had to be scrapped. But it held load no problem, and when I could get it to start, it never had much issue with moisture after I got my Vac sorted out.

So what was the difference? Why didn't it have a problem and every cascade since did?

The filters. I got a bunch of solid core filters for a good price, and on single stage systems, especially the big ones, and on the High stages, they're mint. They even look good too They appear to NOT like being operated when frozen though.

I redid the Low stage with NO filter at the captube since I didn't have a bullet on hand, and put a filter just after the desuperheater so that it would be sitting at or close to ambient temperature when it was working. Not ideal as it's meant to filter liquid, not gas, but I wouldn't want to run without any filter.

Ran fine, no blockage, no problem. I only had a 3/4 charge of R23 left, but I toppped up with 402a enough to get it working, and it still hit -102 or so no load, but load was about -65 with it blended with 402a, so not the best result. Still, I've learned a lot this time as well, as you do with all the mistakes you make, and the next one will rock when I can get some new gas, that is.

It also means that when the new gas is here, I can redo the other complete cascade, changing the filter, and there's a good chance it will work normally after all the problems it's had. That's some good news, and I'll be dealing with that one first to see if the theory is 100% correct but I'm very confident I've foudn the culprit.

So...Cascades are on hold for now, but not forever :B

Cheers

Gray

 

[fatty]

C'mon Grey sell a kidney and get that bad boy up and running :O

Great job mate glad you found the problem pity about the gas though oh yeah as for 410 I wouldn't, from all accounts its not a very forgiving gas

 

[Gray Mole]

Funny enough, I'm finding uses for many a gas these days. After seeing some of the results of the guys blending gasses, it might be of some use.

On it's own though, 410 is a tough gas to work with. It's about the very max single stage gas you could possibly use, but considering the head pressure is already quite high with 402a, 410 would be only for something with a massive condensor, and a lot of other extra parts to make it work safely. Otherwise a 410 compressor would be needed, but the way they're designed you don't get much benefit over lower pressure gasses.

Anyways, I can't get anything ordered until after New year so I'm gonna have a little break form the cascade, but that's ok. I even told the wife and she didn't tell me I wasn't allowed lol so I'll be having more at some point soon I just need to decide which Kidney to sell

Gray

 

[fatty]

Well I may get some compressors off you in the new year will wait and see, I am still very keen to get me a bigger cascade up and running not sure what temps to expect with the R507/CO2 mix but will see how I go

 

[Gray Mole]

Yeah, I'd love to see you get a good cascade running mate

I'm really looking forward to redoing the other one now too, cas if it fixes it up and it runs as normal, then I'll finally have my first proper cascade 100%.

Anyways, it also gives me some 'research' time to do things like check if a MM case will fit a cascade and things like that.

Still hate to have to wait tho...8)

Gray