My first Evaporator Design :) 'The Daisy'

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Originally Posted by mytekcontrols

as well as vacuum insulated thermal isolation KF-50 flange.

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I always wondered when someone would get to vacuum insulation. Also vacuum noise attenuation, sound waves can't travel through a vacuum. You would have to be sure 100% of the heat of compression is rejected to the condensor or a auxiliary cooling loop.


http://www.youtube.com/watch?v=ce7AMJdq0Gw

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Originally Posted by wdrzal

I always wondered when someone would get to vacuum insulation. Also vacuum noise attenuation, sound waves can't travel through a vacuum. You would have to be sure 100% of the heat of compression is rejected to the condensor or a auxiliary cooling loop.

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Hi Walt -- cool video.

My business is all about cooling within a vacuum. Specifically for the purposes of cryo-pumping water vapor by freezing it to cryocoil. basically the deeper the vacuum the colder the capture coil needs to be in order to keep water frozen (check out: Temperature vs. Vacuum Pressure). In most vacuum coating systems this takes a temperature down into the -130 C range, and in some of the ultra clean processes they might need -150 C or better (CryoBUG territory).

hi mike well come to back,
you ask that
In most vacuum coating systems this takes a temperature down into the -130 C range, and in some of the ultra clean processes they might need -150 C or better (CryoBUG territory).
which temp is better ,-130 or -150 or -170
and vacuum coating systems need the vacuum is ? or the vaccum is low is better.

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Originally Posted by kang-China

hi mike well come to back,
you ask that
In most vacuum coating systems this takes a temperature down into the -130 C range, and in some of the ultra clean processes they might need -150 C or better (CryoBUG territory).
which temp is better ,-130 or -150 or -170
and vacuum coating systems need the vacuum is ? or the vaccum is low is better.

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Colder certainly doesn't hurt, but what it comes down to is what level of vacuum does the particular coating process require. Then using that chart that I provided the link to, and selecting an appropriate temperature for that pressure, would insure sufficient water vapor cryo-pumping. Some other factors come into play, like how much ice build up is anticipated during the coating run, or how long do you wish to go before defrosting the cryosurface. Because as the ice layer increases, it creates an insulating barrier between the inside of the vacuum chamber and the actual surface of the cryo-coil. If this gets too thick, then the cryo-pumping of the water vapor will slow down and ultimately stop. To counteract this, a colder coil temperature than initially required will make up the difference.

As to what level of vacuum is required for a coating process, that would depend upon what it is that you want to coat, the materials to be used, and the quality that is desired. Usually a lower vacuum = a cleaner or higher quality coating.

Things that are typically coated...

1. Eyeglasses
2. Camera & Telescope Optics
3. CD's, DVD's, Blu-Ray Discs
4. Hard Disk Platters
5. Architectural Tinted Windows
6. Semiconductors
7. Integrated Circuit Chips
8. Metalized Coated Plastic Parts
9. Colored Cellophane
10. Helium Filled Party Balloons

And this is just a small sampling.

I hope that answers your questions Kang :)