evaporator block design help

[kryptobs2000]

I made a post about this about 2 months ago, but I got my block of copper, it's about 50x50x18 and the top is about 4 or 5mm. so I was just going to make a maze type of thing swirling around outwards. But, and sorry if this is in one of the sticky's I skimmed through the ones that might help didn't see anything, but would this be an effective design (seems easiest) and how big should my channels be, and how big should the walls be?

I drew in marker on the block and my walls are about 2mm thick, the channels are about 3mm, and the outer walls have at least 4mm all around. Would this be fine? and how deep should it be?

edit: I'm just using a dremel to do this, so keep that in mind, it's not gonna be pretty and smooth or anything to say the least.

[reject]

a rough design will have more surface area anyway.
that design will work ok, but im a bit confused.
is it like a cylinder with channels around, then goes inside a outer tube and brazed on? i dont see how you can cut inside with a dremel. i think i actually have no idea what it is

[kryptobs2000]

No, I just have two seperate blocks. One block is 18mm high (give or take) and another is 5mm high (give or take). I just cut downwards, to carve out the channels with the dremel. Then I just cut a whole in the 5mm block, put the suction line through there (with the cap tube inside I guess) and braze that on as the top of the evaporator block. And it's not a cylindar. It's a cube. Then it has channels... I'll draw up a quick thing in gimp or something and edit this post to add it...

http://img128.exs.cx/img128/4237/u6yblockd.jpg

[gkiing]

No, I just have two seperate blocks. One block is 18mm high (give or take) and another is 5mm high (give or take). I just cut downwards, to carve out the channels with the dremel. Then I just cut a whole in the 5mm block, put the suction line through there (with the cap tube inside I guess) and braze that on as the top of the evaporator block. And it's not a cylindar. It's a cube. Then it has channels... I'll draw up a quick thing in gimp or something and edit this post to add it...

http://img128.exs.cx/img128/4237/u6yblockd.jpg

The best way to do it is to do what you said, cut the grooves with the dremel, and then put 1/4" holes on top of the groove to increase the surface area. It would look like a maze with a center channel and a hole every 2mm or so. I have personally tested this and it works quite well.

[kayl]

walls 2-3mm and drill about 15mm leaving 2-3mm base for channels, works

personally i predrill holes with drill press, can get them really cheap. hole size about 0.5mm smaller than dremal bit using, makes it easier and that way ya get exact 2-3mm base with max surface and and overall area.

[kryptobs2000]

alright well thanks, I'll post some pics of how it looks, it'll probably be at least a week though, I spent about 20 min. on it today, and barely got anything dug out :(. It's gonna take some time for sure.

[reject]

ah right that design
tip: dont make the outer walls too thin. and the base needs to be a bit thicker than walls i think
so the captube enters at the center, and then the suction pulls from the end of the spiral?

[_Eduard_]

I was thinking... is it possible to use a waterblock from copper (such as the swiftech blocks)?

[gkiing]

I was thinking... is it possible to use a waterblock from copper (such as the swiftech blocks)?

Definately not. It will pop at 10psi or so and send pieces flying at your face..

[reject]

because they are not heavy duty, not pressure tested enough
howesver you can do the opposite in some cases

[_Eduard_]

Well ok just to prove you're wrong here are some facts I dug up from the Swiftech site:

Long term reliability: built to last

"Monolithic" construction: the base and housing are brazed together, assuring long term integrity of the joint.
The copper housing features an unlimited durability compared to acrylic tops used in competing technologies
The all copper construction eliminates galvanic corrosion.
100% quality control at the assembly line level: each block is factory tested to 25 psi (1.7 bars) to guarantee zero defect.

http://www.swiftnets.com/assets/images/products/MCW6002/MCW6002-A.gif

I bet it will handle lot more pressure... Its all copper. Maybe needs some slight modification

[HawainPanda]

er...don't bet on it.try dangerden...their block would work

[kryptobs2000]

How could I make the cap tube go out through the suction line? I don't get how to make that go through the walls in the evap block so it leaves there.

[Aphex_Tom_9]

How could I make the cap tube go out through the suction line? I don't get how to make that go through the walls in the evap block so it leaves there.
with a block like that, the capline should go in the center hole, and the suction should be on the outer one.

[kryptobs2000]

no, I meant, I wanna make the capilarry tube run through the suction line, and then come out later. How would I do that?

edit: ah.. I think my drill bit sucks, can anyone recommend me some bits to use. Either from www.lowes.com or www.homedepot.com It just uses any standard dremel bits.

[hatemi]

The older Swiftech blocks that have aolut of diamond shaped pins inside would make a decent base for evap. All you would need to do would me making some cap and braze it to the base...

[kryptobs2000]

Well I already have the blocks of copper for this, and I've started it. Havn't gotten but a few holes about 4mm deep. I don't got the money to go buying another block, which is why I'm making my own anyways.

[HawainPanda]

yeah..plus its fun :D
i dunno, i can't help u pick a bit...as i buy diff for the cnc machine, but i think carbide tips are the best...that have 2-3 flutes(um..those are ...like the cutting edges)

[reject]

no, I meant, I wanna make the capilarry tube run through the suction line, and then come out later. How would I do that?

u need to have the captube enter the suction line near the block. like this
braze it REAL good, but you know that :D

[kryptobs2000]

oh, I was thinking I had to have the suction line run overtop of a few channels, and go up through the suction line. I didn't even think of what your doing. Both seem hard... well... not easy lol. I have 0 brazing experience. First time I've done this.

[reject]

brazing is easy i did it at school with an oxy torch. mapp shouold be a lot easier
practice on some crap first
ive seen this method on someones block before might have been kayls

[kryptobs2000]

Yeah, I'll be using a mapp torch. What do I do, like, do I apply the solder to the base of the top, and then along the top of the channel walls, then just heat it up so they bond, and apply it around the edges or what? And I was thinking of cutting grooves in the walls, and running the cap tube through there, and Just go up through the suction line through there. How would I do that so there are no leaks from channel to channel, or should I just avoid that. Sorry if any of that is hard to understand.

[reject]

nah i get it.
im not sure but i would just make sure they match up real good, and that ithey fit together flat then braze up the seams.
by solder u mean brazing rod right? ive always confused when people say solder in welding, to me solder is vmod
if someone can confirm my diagram works, that would be a lot less work than sandwiching it

[reject]

oh the technique:
you heat the contact area till red hot, then apply the rod out of the flame so its not messy. it will flow like soldering but IIRC it sparks a bit

[gkiing]

Well ok just to prove you're wrong here are some facts I dug up from the Swiftech site:


Even still.. that evaporator will be dealing with pressures upwards of 95PSI (OR GREATER) when the system is off. IT WILL NOT WORK SAFELY. If there was even a possibility of it holding everything would have to be brazed. Also the thickness (or lack of, in this case) of the walls doesnt help either.

Try putting 95psi through that, I'm 110% sure it would blow apart (at least if it wasnt brazed all over and reinforced somehow).

[kryptobs2000]

I was wondering, would this be more evective, at least theoreticly, than a smoother milled block. I mean, it will have alot more friction obviously, as long as it has enough surface area, wouldn't it work better due to the friction? Problem of course it getting the surface area because thats easier and more precise with a miller, but you see my point?

edit: umm... sorry for all the spelling problems I had there haha

[gkiing]

Friction isint an advantage, but surface area is. The prometia evaporators are a hollowed out block with square pillars much like the round ones in the swiftech design. A messy looking drill press block will usually have more surface area than a milled block, and all the rough cuts and chunks in the metal aid to the heat transfer.

[kryptobs2000]

I thought that friction would be better because... well I mean it's just transfering energy, heat/cold. Maybe I'm wrong, I'm no.... physicist or w/e field were discussing it's just what I gather from my thoughts. The more friction the refrigerant has, the more cold it transerfs into the block.

Maybe this isn't the right way of thinking, but I like to understand thing versus just knowing whats right. You know what I mean, that way I can apply it do different things. Could someone please explain this? I obviously understand the more surface area, and the more rouch edges there are I would think that would increase the surface area for obvious reasons, but can someone explain how friction plays a role, or does it not have anything to do with it? This dosn't have anything to do with my design obviously, I cannot increase or decrease friction with what I have, I'm just wondering for curiosity sake.

[HawainPanda]

curiousity is good :D

[reject]

i think the gas removes heat not adds cold

[gkiing]

i think the gas removes heat not adds cold

The liquid removes heat by changing into a gas (it takes energy to go from liquid --> gas). Im not sure about friction, I would think that it being too restrictive is bad.

[kryptobs2000]

Well a reason of my thinking that friction helps is with water cooling, if the water has high pressure/flows faster, why is it more effective (usually) at removing the heat? I would think that would be because of friction, it's not because the water dosn't get as hot, because it goes in a continious loop for the most part.

i think the gas removes heat not adds cold the gas carries away the heat yeah, but I mean... I think it's kind of different in watercooling than phase change..ing lol, because the water is in most cases the same temperature as the ambient room temperature. So it takes heat away, where as with a phase changer your goal is to make the processor cold, not just remove heat. So the colder you can make the evaporator block the better. From there it is the coldness of the evap block, vs the heat of the chip. I know I'm not explaining this in uh.. well, in a scientific way or whatever by any means, but this is my understanding of it. If all you did was take heat away, you'd never get below ambient.

I'm not saying everything I said is right, I'm just saying thats how I see it, feel free to tell me I'm wrong lol. Anyways, That second part dosn't matter, I'm just wondering what role friction might play, wouldn't really help me, but still, might be helpful to know, and hurray for run on sentences! :)

[G H Z]

Coarse surfaces in intake manifold's will increase turbulance and create a better fuel mixture. I wonder if that might apply here. I saw a clip where the evap had a clear top so you could see inside the block and watch what happened to the refridgerant after it left the cap tube.

There was still alot of liquid even in the outflow of the evap. It seems to me that if you could turn the liquid to gas faster somehow, and more completely possibly using a coarse surface, then cooling would also be more effective.

Polished intake manifolds on the other hand do flow faster, but the mixture is much less vaporized.

Or what about a cascade(water block), designed exit into the block. Has anyone ever seen any thermal testing of evap's that shows what part of the block is the coldest? Is it directly opposite the cap tube discharge, or further away as the gas heads for the block's exit?

[Aphex_Tom_9]

I saw a clip where the evap had a clear top so you could see inside the block and watch what happened to the refridgerant after it left the cap tube.
/slightly offtopic- WHERE?

[gkiing]

/slightly offtopic- WHERE?

That was made with a dangerden maze 4- I think. I highly advise against this, its quite unsafe. It is likely that the lucite top on the block would crack after a few minutes, and the gas would leak out. Also, this was probably used only as a demonstration, as the water block could not hold up to the pressures when the system was off.

[kryptobs2000]

Ok, I MIGHT have a problem. I drew a pic with gimp, it's obviously not to scale but let me try to explain. I would LIKE to have a spiral going outwards. However, the parts in green, I am not sure if I will have enough room to make that channel. The part at the bottom where it zig zags, I don't think I can fit a channel there twice (I would need two more). So basically, would it be bad to make it zig zag like that? And what about having something like at the top left, is that a bad idea to make it split like that? Sorry, I'm going to try and get my friends digital camera and take some pics, I know it's hard to understand from this. For now, if I can't make it spiral all the way, would this design be effective as well? It's the best I can think of with the room I have.

edit: The red is the part I already have carved out, the green uh.. well pretend it's blue, I dunno what I was thinking lol
http://img110.exs.cx/img110/4779/blocka8mx.jpg

edit: well, I went with this idea, cause I can't see any other way to do it, hope it'll be ok.

[kayl]

oh, I was thinking I had to have the suction line run overtop of a few channels, and go up through the suction line. I didn't even think of what your doing. Both seem hard... well... not easy lol. I have 0 brazing experience. First time I've done this.

you dont have to have capillary line going down the suction line. wrapping around the suction line does the same thing under insulation.
but if you were to run it through the suction line do what you said in you quote.

[blinky]

Even still.. that evaporator will be dealing with pressures upwards of 95PSI (OR GREATER) when the system is off. IT WILL NOT WORK SAFELY. If there was even a possibility of it holding everything would have to be brazed. Also the thickness (or lack of, in this case) of the walls doesnt help either.

Try putting 95psi through that, I'm 110% sure it would blow apart (at least if it wasnt brazed all over and reinforced somehow).but whats to say that he cant reinforce the brazes himself, and then test with nitrogen or something. im betting he could make it strong enough

[HawainPanda]

wait...the waterblocks i heard had really thin sides.i dunno, lol, you should def try

yeah, that movie was actually posted here, try searching for it, i saw it a while ago, but i can't remember wat it was called sorry

[gkiing]

You can try ising the swiftech brazed, but It's easier and cheaper to make your own.

[Epsilon]

http://www.haegkoeling.nl/site5.html

That is the clip were you can see the gas boiling :D

Good luck :)

[kryptobs2000]

I got a pic of what I have so far. I was working on it when the drill bit got stuck, and when I tried to pull it out with some pliars it broke :/ Dunno what I'm gonna do to get it out now any suggestions? But anyways, how's it looking so far, I was going to zip zag it back, and then end it on the bottom left there.

http://img111.exs.cx/img111/467/blockpic20wf.th.jpg (http://img111.exs.cx/my.php?loc=img111&image=blockpic20wf.jpg)

[kayl]

keep going. i have 2 blocks that have snapped drill bits in them, they still work
add character
thats why i use 5mm bits not to drill holes.
3mm snap so easy.

[kryptobs2000]

So you mean just don't worry about digging it out just leave it in and go around it? lol, I guess I can do that, I was using a 1/8 bit, and it worked fine (although it did snap) didn't wanna go pick up a new bit so I tried a 6/32 and it snapped really quick (the one in the pic). So I went and got a new bit, guess I'll leave it there, gotta sand it down or something tho. Should have the block done tommarrow tho, then I'll take some pics if I still have the camera then (it's my friends dads). Me and my dad were gonna work on the phase changer tommarrow, so... well I'd like to say it'll be done by the end of next weekend, but me and my dad arn't too reliable for doing things, so... for all I know it could be another 2 months lol. But hopefully, I should have it done by january at the latest.

edit: Oh, didn't ask, how's the block look tho? Think it'll be good? It's the first one I've made obviously, and tho I've seen a few pics of others, I really don't have anything to compare to.

[kayl]

yeah just go around snapped drill bits. With the snapped drill bits take them down with grinder carefully to get them flat with the block
with the maze designs really cant go wrong as long as there are channels and down braze the capillary tube shut, it should work quiet well.

here are some of me evaps, might be able to get some ideas from them.
http://teampuss.com/forums/viewtopic.php?t=327

[buffarilla]

great info still learning

[HawainPanda]

Awesome work!, I think ur maze will do very well, although u def gonna have to mill much deeper cus ur channels are so thin, see if u can try and cool your bit when ur working with it, I riged an mag3 pump to continuously poor coolant on my block and bit, my bit hasn?t broke yet, although the speed of your mill will prob help also

I think kayl used a spray bottle, to spray on the block everyonce in a while..that should work and should def help cool your bit, so it won't break as fast

[kayl]

CRC helps and easy to get.

[kryptobs2000]

I just dipped my block in a bowl of water, cools it right off.