[Amps] water cooling tips

[John Lyles]

Jim Tonne is correct, not only for the filter but for the bottles that clean up big cooling loops. They call this technique a sliptstream process, where it is a side loop with about 5-10% of the main flow. We use Culligan unibed and oxygen bottles in what is called a polishing loop, the two of them not only remove ionics but also oxygen from the water. In larger tubes that can boil water (like vapor and multiphase cooling), Eimac adn the other manufacturers want very low dissolved oxygen as well. 

Pure DI water can get as resistive as 18 Megohm-cm, which is about the theoretical limit. This water would be very difficult on fittings and metals as it will scavenge ions, which causes migration through the hoses, and can plate the metal ions elsewhere. It is very difficult to maintain this perfect water in this condition, as it degrades as it strips whatever ions it can through the cooling system. You don't want pure DI water, but a compromise between 100 kilohm-cm and a few Megohm-cm is appropriate for most high voltage systems that need cooling. 

73 
John 
K5PRO

 
> Message: 4
> Date: Sun, 20 Dec 2009 23:00:17 -0500
> From: "Carl" <km1h at jeremy.mv.com>
> Subject: Re: [Amps] water cooling
> To: "Dr. David Kirkby" <david.kirkby at onetel.net>, "amps"
> 	<amps at contesting.com>
> Message-ID: <01f501ca81f2$1e3503a0$6501a8c0 at DAVES>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> 	reply-type=original
> 
> How conductive is pure deionized water? The tube I have here ran close to 
> 7kv and the water flowed thru clear plastic tubing.
> 
> Carl
> KM1H