[Amps] Oil v Water cooling

Sat Apr 18 13:29:00 EDT 2015

Hi, just to clarify, I did not write what was attributed to me here.... my post is further down!
> 
> David Lisney wrote:
>> Deionized water can contain dissolved minerals that the demonizing
>> process cannot remove, namely dissolved silicates which are plentiful
>> in Florida water. (elsewhere I have no knowledge) These minerals do
>> get deposited in the cooling circuit and an acid rinse does not
>> dissolve them. (they are white glass like coating) I will add that
>> operating these high power tubes with water on their collectors
>> (through the Ammeter and overload relay coil) is made much easier by
>> grounding the collectors and supplying the high Voltage to the cathode
>> with the power supply terminal with the surplus of electrons. (the
>> negative terminal) * after 50 years and 5 months.
> 
> I started replying, before I realised this was a troll!  Very well done,
> and you had me for a second until I re-read your last sentence a few
> times! Point taken as well, that the water thing has been done to death.
> 
> To be perfectly clear though, deionised water will be near "absolutely
> pure" - far purer that steam distilled water.  I spent a year in the lab
> of a thermal (gas powered steam) power station, and they used the
> deionising process specifically to remove silicates and others.
> 
> In any case, it is no matter as deionised "battery water" is available
> widely at auto-parts stores. 
> 
> KA4INM <ka4inm at gmail.com> wrote:
> 
>>   Water requires more energy per gram of liquid to change its
>> temperature.  Water can hold more heat energy than oil.
> 
> The heat-removal issue has already been resolved, and that level of
> cooling is not required.  There is only about 5KW continuous, not 20KW. 
> 
> And as far as hoses blowing off after being double clamped and resultant
> oil-sprays, I think that is a nonsense.  The hydraulic hose industry
> uses only single clamps, and they are rated to many thousands of PSI.  I
> will be using solid steel pipework with Swagelok compression fittings,
> and there will be no more "blowing off" in my shack other that what is
> usual.
> 
> I think I see the problem:  People cannot get past their fears - having
> a highish temperature flammableish liquid in the shack. 
> 
> And at first glance, 4KV at 2amps right next to your cup of coffee is
> just as risky a proposition, BUT we build the amp properly don't we, so
> that isn't a risk.  If I make "HT" mistakes building an amp of those
> proportions, then I shouldn't be building amps at all.
> 
> Oil will be fine.  Proper pump, proper steel pipework, proper steel
> fittings, and so on, done properly, just like your perfectly safe HT supply.
> 
> Steve
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> ------------------------------
> 
> Message: 3
> Date: Fri, 17 Apr 2015 14:44:05 -0600
> From: John Lyles <jtml at losalamos.com>
> To: amps at contesting.com
> Subject: [Amps]  Oil v water cooling
> Message-ID: <55317095.2020302 at losalamos.com>
> Content-Type: text/plain; charset=windows-1252; format=flowed
> 
> On 4/17/15 10:00 AM, amps-request at contesting.com wrote:
>>> Hi, I believe that not all "distilled water" is suitable for this, you may
> need to specify "deionised water". The water conductivity needs regular 
> checking,
> it will rise as it gets contaminated by traces of solder flux etc...I 
> seem to
> remember where in a published design for a watercooled amplifier that 
> about 6"
> from the tube anode that the plastic cooling pipe went through a brass 
> coupler
> that had a meter connected between it and chassis ground to monitor 
> leakage current.
> Regards David G0FVT
> 
> Yes, exactly. The brass coupler and meter just insert a volt meter into 
> the water pipe, to measure the actual leakage current, like measuring 
> the voltage drop across a shunt. Getting it calibrated is the trick. If 
> you have 6 inches of pipe from the brass sleeve to ground and now the 
> diameter, can calculate the resistance for a given value of resistivity 
> of water.
> 
>>    As a retired* broadcast engineer with plenty of experience
>> maintaining vapor and water cooled transmitting tubes I highly
>> recommend ONLY "steam distilled" water over any deionized water.
>> Deionized water can contain dissolved minerals that the demonizing
>> process cannot remove, namely dissolved silicates which are plentiful
>> in Florida water.   (elsewhere I have no knowledge)
>>    These minerals do get deposited in the cooling circuit and an acid
>> rinse does not dissolve them.  (they are white glass like coating)
> 
> The literature from Varian + Eimac (CPI) and the other tube companies 
> recommends deionized water. CPI website has this info in several app 
> notes. By using proper resin bed followed by an oxygen removal stage, 
> mineralization is not a problem. A continuous process through these 
> bottles (available from Culligan and Cuneflow) will keep the water pure. 
> This is industry practice, from companies like Continental Electronics 
> to users such as our particle factory. In a closed loop system, the 
> water must be continuously 'polished' this way, and the equipment is 
> called, appropriately, the polishing loop. The bottles are replaced 
> about once per year in the installations that I maintain/design.
> 
> Steam distilled water might be a good starting point, but I cannot 
> imagine that the closed-loop process includes a distillery and the 
> incipient energy consumption required to continuously boil and re- 
> condense a large flow of water in real time.
> 
>>    I will add that operating these high power tubes with water on their
>> collectors (through the Ammeter and overload relay coil) is made much
>> easier by grounding the collectors and supplying the high Voltage to
>> the cathode with the power supply terminal with the surplus of
>> electrons.  (the negative terminal)
>> * after 50 years and 5 months.
>> -- Ron KA4INM - Youvan's corollary: Every action results in unwanted
>> side effects.
> 
> Indeed, Klystrons and IOTS are typically run that way, with the 
> collector grounded or just off ground (to measure body current from the 
> voltage between the body and the collector to see how much beam is being 
> spilled). Then the negative HV is applied to a floating cathode/filament 
> with isolated heater transformer.
> 
> For those of us using PGT (power grid tubes) though, we typically have 
> B+ on the anode and have to insulate those pipes.
> 
> Oil vs water:
> I like water only in that we always find leaks and water on the floor 
> and equipment is a lot easier to clean up. The federal gov't doesn't 
> like having oil spills, even indoors. Also, for the Specific Heat 
> Capacity as Ron suggested.
> 
> 73
> John
> K5PRO
> 
> 
> 
> 
> 
> 
> ------------------------------
> 
> Message: 4
> Date: Fri, 17 Apr 2015 16:14:09 -0500
> From: donroden at hiwaay.net
> To: amps at contesting.com
> Subject: Re: [Amps] Oil v water cooling
> Message-ID: <20150417161409.35516ljqio500joh at webmail.hiwaay.net>
> Content-Type: text/plain; charset=ISO-8859-1; DelSp="Yes";
>    format="flowed"
> 
> Quoting John Lyles <jtml at losalamos.com>:
> 
> 
>> Then the negative HV is applied to a floating cathode/filament with  
>> isolated heater transformer.
> 
> 
> Yah..... REALLY isolated !!!!
> 
> 
> Don ( remembering the old GE  "Austin Ring" filament transformers ) W4DNR
> 
> 
> 
> ------------------------------
> 
> Message: 5
> Date: Fri, 17 Apr 2015 23:36:56 +0000
> From: "Fuqua, Bill L" <wlfuqu00 at uky.edu>
> To: Manfred Mornhinweg <manfred at ludens.cl>, "amps at contesting.com"
>    <amps at contesting.com>
> Subject: Re: [Amps] Oil v water cooling
> Message-ID:
>    <B7E8B5B4A202074084E2515A7B10A7F34AEFD8C4 at ex10mb02.ad.uky.edu>
> Content-Type: text/plain; charset="us-ascii"
> 
>  Oil cooling/bath was mostly been used either for tube power amplifiers used in high altitude aircraft where the break down
> voltage drops with altitude as well as cooling capacity of air or in high voltage DC power supplies for X-ray equipment or
> hv power supplies for research. We had one that was over 300kV and when we decommissioned it had to dispose of 
> hundreds of gallons of oil. 
>  73
> Bill wa4lav
> 
> ________________________________________
> From: Amps [amps-bounces at contesting.com] on behalf of Manfred Mornhinweg [manfred at ludens.cl]
> Sent: Friday, April 17, 2015 3:27 PM
> To: amps at contesting.com
> Subject: Re: [Amps] Oil v water cooling
> 
> I worked for 18 years at a scientific organization where we used a variety of
> liquid-cooled systems. For systems requiring the coolant to be near room
> temperature, or somewhat cooler, often close to freezing temperature, we used a
> water/glycol mixture. For very cold systems we used liquid nitrogen vapor phase
> cooling, and for even colder ones liquid helium. I can't remember any system
> using oil as a coolant, but maybe there was. I didn't know absolutely everything
> we had there.
> 
> What I do know: Despite professional construction and maintenance, spills did
> happen. Small spills while connecting and disconnecting equipments, or from
> leaks in pumps, filters, fittings, etc, and large spills when something broke.
> It was very good to have just water/glycol spraying, flying and flowing around,
> rather than oil. Pure water would have been even nicer, but wasn't usable for us
> because we sometimes needed temperatures around freezing.
> 
> I had to fix a few such problems. Among them was corrosion, both from the inside
> and from the outside; cavitation; material fatigue due to microvibration from
> the coolant's turbulence; and many others, difficult to list. Sometimes
> something heavy would fall on a cooling hose, sometimes someone would make a
> mistake, some hoses develop pinholes without warning, a barb might have a
> scratch making it leak, and so on.
> 
> The simple fact is: Leaks happen. Liquid cooling is excellent in many situation,
> but one needs to consider the possibility of a leak. In my shack, if I have a
> water leak, it's less bad than spilling a cup of coffee. But an oil leak is very
> much worse!
> 
> Technically, the lower thermal conductivity, heat capacity, and higher viscosity
> of oil requires a very much higher pump power, to extract a given amount of
> heat. That means a bigger, heavier, more expensive and noisier pump, that wastes
> more energy.
> 
> On the other side, of course, oil has the advantage of being an excellent
> insulator, not causing corrosion, inhibiting it, also has a much lower
> dielectric constant and loss.
> 
> With hoses, be careful. While water can support corrosion of metal, it's safe
> with hoses. Oil is safe with metals, but degrades many hoses!
> 
> Both coolants have their places. But water has more of them.
> 
> Manfred
> 
> ========================
> Visit my hobby homepage!
> http://ludens.cl
> ========================
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
> 
> 
> ------------------------------
> 
> Message: 6
> Date: Sat, 18 Apr 2015 05:28:33 -0400
> From: "Roger (K8RI)" <k8ri at rogerhalstead.com>
> To: amps at contesting.com
> Subject: Re: [Amps] Oil v water cooling
> Message-ID: <553223C1.1060307 at rogerhalstead.com>
> Content-Type: text/plain; charset=utf-8; format=flowed
> 
> 
> 
> It's been a long time, but as John said, these solutions are ion hungry 
> and particularly DI water.  We measured resistivity at ohms per cubic 
> centimeter,.  It's not just solder, they will reduce a brass hose 
> fitting to a dull copper color that you can crumble with your fingers.  
> It also likes copper, to the resistivity monitoring mentioned several 
> times is a necessity. We went through thousands of gallons of DI water.
> Oil can most likely be used on almost any water cooled tube, but water 
> is likely, by far, the best for carrying heat away.  I can't imagine 
> using oil
> 
> 73
> 
> Roger  (K8RI)
> 
> 
> 
>> On 4/16/2015 12:13 PM, David Lisney wrote:
>> Hi, I believe that not all "distilled water" is suitable for this, you may need to specify "deionised water". The water conductivity needs regular checking, it will rise as it gets contaminated by traces of solder flux etc...I seem to remember where in a published design for a watercooled amplifier that about 6" from the tube anode that the plastic cooling pipe went through a brass coupler that had a meter connected between it and chassis ground to monitor leakage current.
>> Regards David G0FVT
>>