Film-Tech Forum ARCHIVE: Water cooled gate

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Posted by Chris Erwin (Member # 176) on 12-27-2000, 05:07 PM:

On a Simplex PR1014 I'm looking at, I need to go with a water cooled gate. I'll be running 4k Xenon.

Just checking around with some literature I have around this place, I estimate $300 to add water cooled gates to this projector.

Is this in the ball park? Suggestions?
--Chris

Posted by Gordon McLeod (Member # 33) on 12-27-2000, 07:03 PM:

I would also add the air blower as well

Posted by Pat Moore (Member # 380) on 12-27-2000, 09:14 PM:

I don't remember the price of the water-cooled gate option offhand, but it's not that much. But remember you'll need to circulate water through it, so whether that's with one of our circulators or something homemade, keep that in mind for your costs. I think that budget number is probably okay with everything included.

Personally, I'm not a big fan of the shutter blower unless you're running a really "hot" 4000W or more. Water is your best option. Most xenon systems also include an additional in-line heat filter that's really required with 4kW operation -- be sure that's there as well.

(Boy, am I getting to dislike that picture...)

Pat

Posted by Paul G. Thompson (Member # 655) on 12-27-2000, 10:35 PM:

Yeah, Pat! The last time I saw you in real life at ShoWest, you had more hair!

But, my picture is worse than yours. Before mine was taken, I got a haircut. I looked like a rear end with dentures. And, I still do! (No comments, please)

Posted by John Walsh (Member # 168) on 12-27-2000, 10:38 PM:

I sort of felt that a water-cooled gate was only desirable in that it kept the gate/trap cool to the touch. That way, you don't have to worry about burned fingers when you thread. A good thing, of course, but water-cooling the gate did nothing for the picture.

A blower did the same thing, but some blowers are designed to blow on the back of the film, (while in the aperture.) When film stops in the gate, the heat causes it to bow back towards the light, which causes a slight focus flutter. The air blast pushed it back, reducing the flutter. Century called this their "Cinefocus" option. I don't if the Simplex blower just cools the gate, or also blows on the film.

Several lamps I used had heat filters in them. I don't know for a fact, but what I heard was that, with a heat filter, the light is reduced by about 10%, but the heat was reduced by about 50%.

I currently run 3000 watt Xetron consoles with Simplex projectors. No water cooling and no projector gate air blower. The gate is only warm when removed. Since my 3000 watt lamps run so cool, I was wondering why you feel water-coolers are needed. For example, are you sure that the regular lamp exahust is at the proper CFM level? Are you having focus problems?

I realize that you have 1000 watts more than I, but I personally thought that a combination of air blower and heat filter was the most effective for picture quality. The blower may also keep the gate/trap cool enough to prevent "hot fingers."

Note though, that I am limiting my comments to the 4000 watt range. If higher wattages are used, you actually need everything you can get.

Posted by Steve Guttag (Member # 268) on 12-27-2000, 11:19 PM:

I have always been a proponent of water cooling for 2500 watts and above.

Certainly, lamp exhaust and how much heat is coming out of the lamphouse are big factors. Water cooling helps in many regards, including keeping the trap cooler and minimizing expansion of the trap and aperture plate.

The G-4400 water cell isn't very expensive (less than $100, I believe)...when you order it...ask for the kit (I don't have the 52-xxxx number memorized). With the kit, you will get the water cell, hanger, nylon extension tubes with clamps and adapter tubes so typical water circulator hoses fit! That whole rig typically sells for just over a $100 street price.

To Pat: Has Strong considered adapting the 35/70 water manafold system for the 35mm only machines? The reasoning is that with the manafold, the trap is no longer held captive by the tubes.

Steve

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"Old projectionists never die, they just changeover!"

Posted by Chris Erwin (Member # 176) on 12-28-2000, 06:47 AM:

Steve: I was taught pretty much the same thing. (except the number was 2,000w) We have ran 4k without water cooling, where I used to work. (but just until someone could get the parts to fix the circulator! we had an old ORC 4k behind a PR1014)Those gates were toasty. (read: OUCH!)

Pat: I'm wanting to put an X-60C behind this classic PR1014. Gotta love that lamp. (especially as a ol' workhorse in a large indoor or in my case, an outdoor theater)

John: I just feel that the water cooling will be a good thing to have. (might run 4,500w-i'd like to have that option if a little extra is needed) We aren't running it yet. I'm still planning my drive-in booth.
Now if I could only win that Publisher's Clearing House on Super Bowl....

Gord/Pat/anyone:Is the air blower for focus, cooling, or does it serve a dual purpose?

Thanks a heap,
Chris

Posted by Pat Moore (Member # 380) on 12-28-2000, 08:20 AM:

Sounds like rules by a lots of different thumbs, huh? Well, here are mine:

I water-cool anything over 3000W, and would water-cool that as well if the customer would pay for it. In the tests I've done, water-cooling seems to do the best job of minimizing film flutter in higher wattage systems. Yes, I know it only controls the ambient temperature of the area around the film trap and not the film itself, but that really is what I've encountered.

4000W Systems always get an additional insertion-type IR Heat Filter. That gets a lot of extra energy out of the light before it gets into the film and is also very influential in the film flutter issue. I lose a little light due to the filter but I don't burn film and the image looks better -- I'll take the trade-off.

Air flow doesn't hurt as a cooling agent, but it's nowhere near as beneficial as water-cooling is. Heat filters and water-cooling are far better. I'd NEVER use additional air-cooling alone. It just doesn't cut it on larger xenon systems, especially with all the short focal length lenses and large-appearing screen images.

Air pressure does help a bit to hold film in position and minimze some types of flex. Remember Century's Cine-Focus? We still use air pressure on large format systems (870's and such) for that reason alone -- but no cooling benefit here at all. The shutter blower on a Simplex does a bit of that, helping to maintain the film's curvature, but the main purpose is plenty of air flow over the shutter and trap assemblies in high temperature situations.

Steve: I'd like to see a fixed water manifold on the Simplex but the design does not readily lend itself to that. Even 35/70 Simplexes have tubes attached to the traps. Century has always used the manifold design. I'll revisit the issue again but in this age of cinema equipment sales, don't look for a fast new design.

Chris: I love the X60-series as well. A big lamp and that's why it performed well, I think, just a lot of volume for the bulb to stay in a reasonable operating temperature range. It could use a little better airflow -- that little muffin fan in the corner worked okay when things were clean and booth exhaust was plentiful, but get some dust in the system and there wasn't enough airflow for me.

Posted by Steve Guttag (Member # 268) on 12-28-2000, 08:38 AM:

>>"Steve: I'd like to see a fixed water manifold on the Simplex but the design does not readily lend itself to that. Even 35/70 Simplexes have tubes attached to the traps. Century has always used the manifold design. I'll revisit the issue again but in this age of cinema equipment sales, don't look for a fast new design."<<

Pat: Yes I realize that the tubes are still attached on the 35/70 design. The big benefit is that with the manafold mounted just below the spot sightbox with just one cap screw, the trap can come out (with just the gate side of the manafold dangling by the surgical tubes. This will allow it to be cleaned more easily and the lateral guide roller lubed properly. The nice part about all of this is that all of the parts already exist. Either no or minimal adaptation is necessary for a 35mm only machine. Again, just an idea.

Steve

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"Old projectionists never die, they just changeover!"

Posted by Mark Gulbrandsen (Member # 72) on 12-28-2000, 08:42 AM:

Personally, I have never been inpressed by either the water cooling or the bug and crud blower for the X-L. The water cooling really only cools the aperature plate and on large lamps of 3K and above is really ineffective as compared to a water cooled Century. It obviously keeps the film from being cooked though. The blower has always been lacking a filter and the machine usually ends up full of dead bugs and dirt and other crud really fast.
Pat,
Why not improve on these features? Overall, Strong has done such a darn good job on the X-L.....
Mark

Posted by Randy Stankey (Member # 64) on 12-28-2000, 02:24 PM:

Let me ask this...

I always imagined that film is momentarily stationary in the gate while a given frame is being projected. I recently discovered that that isn't quite true.

What I understand is that as soon as the shutter comes open, the light heats up the film and it sort of "buckles" toward the heat source. (The lamp.)
The moment the shutter opens, the film is slightly out of focus. As it buckles it moves into the focal plane of the lens and sort of focuses itself. It takes a fraction of a second for the human eye to register the image so the frame is perceived to be in focus even though it didn't start out in focus.

Essentially that means two things:
1) The more wattage your lamp has, the more pronounced this is up to the point of not being able to keep the film in focus. (And eventually burning the film.)
2) You have to remember that even though film projection seems like a fast series of discrete events it isn't. It is a very dynamic process. If you don't remember this you might run into all sorts of problems when "working" in the area of the gate.

So... did I get this right?

Posted by Pat Moore (Member # 380) on 12-28-2000, 03:46 PM:

Randy -- unfortunately you've got it VERY right. Film is very much a "moving picture" and film does all kinds of wild things while it's held "stationary" in the trap. When you're considering an image that's less than 1/2-inch tall, obviously almost anything that happens in the film trap is seen as movement or other image problem on screen.

Kodak has done some great research on this and shown some of their results at a few conventions. Some of their high speed photography of the film as it's pulled-down and then hit with the light are impressive. The film is moving all over, though most of the motion is lateral (towards or away from the light source).

Remember that same film is subjected to light twice; once after pull-down, and then again after the "flicker" blade of the shutter uncovers again. That makes the film pull back toward the heat, then relax a little bit, and then pull back again before it moves out of the aperture. The lens is almost always looking at a moving image.

The industry has referred to this as "film flex" and it is typically a little worse in higher wattage applications. The interesting thing is that the film flexes whether there's a lot of light or almost none at all. Heat seems to increase the amount of flex that occurs.

While it's certainly not ideal, the reason you'll see more "slower" (higher f-number) lenses now as opposed to a few years ago is that slower lenses have a larger "depth of field". That means the film does not have to remain in the exact same plane for the lens to focus the film image on screen. The "slower" lenses accept the fact that the film plane flexes and that it is not fixed. When's the last time you saw an f1.7 lens used?

This affect has to be considered in the "faster lenses for more light" discussions -- you might get more light but image focus and sharpness becomes a problem.

You'll see this is most evident with a "soft appearing" image on screen, or one that seems to float between different points of focus. Chances are that flattening the light field a little (diffusing the heat), using a heat filter (reducing IR and/or UV energy), and using a water-cooled trap (reducing the radiant heat) reduce the effect by minimizing the flex of the film.

Pat

Posted by John Walsh (Member # 168) on 12-28-2000, 04:40 PM:

Well, of course I'm no expert. But I thought that the film was actually moving *somehow* the entire time.

When the intermittent pulls down a frame, the film is still moving both vertically and horizontally; mostly vertically because of momentum/overshoot (jitter.)

While that's happening, the shutter opens. The heat expansion factors of the emulsion and the base are different- which means one expands more than the other. This causes the frame of film to buckle toward the lamp. (I imagine if running film with the emulsion away from the gate was the standard, the buckling would be towards the lens.)

There can only be one distance from the lens to the film that provides optimum focus for a given throw. I think you are right; when a person focuses the image, they are really placing the lens at a distance that is a happy medium between where the focal point would be if there where no heat, and the maximum distance the film will buckle.

Since the heat comes directly from the light, that is why I don't feel there is an improvement in picture quality from water-cooling. A heat filter and "anti-buckle air pressure" seem more effective. Hey, don't get me wrong; If you have the money get the water-cooler. It's just that it seems no theater wants to spend a dime more on anything, and if you have limited funds,

What I'm not sure of is exactly what happens on projectors with curved gates vs straight gates. The idea is good; curve the film to strengthen it, and it will buckle less. But, what about the lens? It can only focus in one place (that focal plane could be on a curve, I guess.) It seems you would need to order a lens designed for curved gates or a lens for straight gates.

Posted by Pat Moore (Member # 380) on 12-28-2000, 07:20 PM:

Film projection lenses have a field curvature built into their design. Typical radius of curved film traps is around 12-inches. However, the lens design also can accommodate flat traps due to their depth of field.

Posted by Randy Stankey (Member # 64) on 12-28-2000, 07:31 PM:

I guess focal PLANE isn't really a true description but "Imaginary Parabolic Dish-Shaped Zone Where the Film is in Focus" isn't very easy to say. (Or type)

I'll just stick with "Focal Plane" if you don't mind!

Posted by John Pytlak (Member # 331) on 12-29-2000, 06:36 AM:

Pat, Randy, John...

All the comments are "right on". Kodak's "Enhanced Theatrical Experience" (ETE) team has been doing some great work in quantifying the factors that degrade projection performance, and has shown some of the work publicly (e.g., last year's ITEA Seminar, this year's SMPTE Conference). Earlier Kodak research by Dr. Fred Kolb and Paul Preo, and work by Willie Borberg, Glenn Berggren, and others have been published in the SMPTE Journal.

The name of the game is getting as much light as possible on the screen, while keeping the film frame cool and stationary. As Pat notes, effective heat filters, gate design, and directed air flow are useful in doing this. Although water cooled gates are primarily for operator comfort, the cooler rails and trap may reduce sticking of the film to hot surfaces, improving steadiness and reducing buckle. Pat is also very correct in noting the effect of lens design, especially choice of f-stop, in compensating for the film flutter that does occur. IMHO, filling screens up to 20 x 48 feet with great 35mm film images is made easy by today's lamphouse, projector, lens and screen technology. Bigger images than this need more care to "do film right". AFAIC, any screen over 25 feet high deserves the quality only 70mm prints can provide. For more information:
http://www.kodak.com/US/en/motion/newsletters/reel/february97/pytlak.shtml (Scope 1.5X)
http://www.kodak.com/US/en/motion/newsletters/reel/fall97/pytlak.shtml (heat damage)
http://www.kodak.com/US/en/motion/newsletters/reel/spring98/pointers.shtml (screen luminance)
http://www.kodak.com/US/en/motion/newsletters/reel/december98/pppp.shtml (70mm part 1)
http://www.kodak.com/US/en/motion/newsletters/reel/march99/pytlak.shtml (70mm part 2)

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com

Posted by Stefan Scholz (Member # 147) on 12-29-2000, 09:47 AM:

I do not believe in water cooling. It does not keep the film cool. Originally water cooling was used with hi power, hi intensity arc lamps. 185 A @ 65 V is around 12 kW+ in power consumption, which has to be radiated to somewhere. You needed water cooling to keep the projector oil cool and prevent loss of lubrication, and of course burnt fingers when threading. At that time mirrors were metallic or glass with metallic coating.Coldlight mirrors were firstly introduced around 1958.
The film was always cooled with forced air blown onto the film from both sides of the gate via nozzles. This helped to keep the film cool, and stay in focus.
Bauer projectors always used this type of cooling, and it was extremely effective. I put little pieces of Nitrate into the gate, the silent type from about 1910, catching fire at 120 C. Lamp with silver coated mirror running at 65 Amp, shutter not running, safetyshutter defeated. Without blower, the film caught fire immediately, the moment the hand dowser was opened. With forced air cooling, the picture stayed in focus for nearly 45 minutes. It never caught fire.
With a 1000 Watt Xenon on Victoria 5 nickel mirror lamp, your fingers are severely burnt, when they are held into the gate while the projector is running. Film is easily burnt - at 1 kW.
My Kinotone FP 30D with coldlight mirrors and interference (coldlight) glass filters (running at 5 kW) never burnt my fingers. The light stays cool. The water cooling option is installed, but not used. I would recommend water cooling for non coldlight applications only. Heat has to be trapped @ the source.
Also it must be kept in mind, water does not absorb energy radiated on the film, the visible light contens absorbed on the film will still heat up and buckle with hi power lamps.

Posted by Chris Erwin (Member # 176) on 12-29-2000, 01:27 PM:

So, I gather that the combination of the two (air blower-for focus, and water cooled gates-for comfort and help reduce temps.)would yield the best possible results, given a high wattage application. (that of around 4k) This providing a good heat filter in the lamphouse.

How much could I expect to pay for both? (my orginal post for water cooled said $300) An extra $100?

Should I really go with both?

How about such a filter for the blower? Mark stated that the unit would fill with crud due to lack of filter. In a drive-in, I would be a little more concerned with this issue, than in a hardtop.

To John P: Has Kodak's Screencheck certified an outdoor screen? (I know there would be a whole new set of rules in regaurds to such) Would that be something to consider? We ozoners want a good projected image for our customers too.

--Chris

Posted by John Pytlak (Member # 331) on 12-29-2000, 02:06 PM:

Kodak's ScreenCheck has not been asked to certify a drive-in. Certainly a few of the criteria would need to be modified (e.g., the need for screen masking, digital sound capability, etc.).

BTW, at the drive-in I worked at, we pulled 120 amperes using 11mm rotating positive HI carbons to light a 42 x 100 foot screen. Really appreciated those Century projectors having water cooled gates! The Ashcraft lamphouses had dichroic coated glass reflectors (Bal-Cor made by Bausch and Lomb?) to reduce the heat on the film. We never measured screen luminance, but my "calibrated eyeballs" estimate that we probably got about 4 footlamberts on a freshly painted screen. (Another area the ScreenCheck spec of 16 footlamberts would need to be modified).

Posted by Gordon McLeod (Member # 33) on 12-29-2000, 02:45 PM:

I find water cooling also improves image stability since the perf area is on the cooler metal rails compaired to hot one with out water

Posted by John Eickhof (Member # 323) on 12-29-2000, 05:04 PM:

I have found the water cooled trap to also be helpful with the growing number of 'green' or fresh from the lab prints! It appears that less surface wax is being transferred to the metal parts when they are cooled. Thus, quiet
projection with less buildup on the rails...so better focus too!
Happy Holidays!

Posted by Dave Bird (Member # 490) on 12-29-2000, 06:35 PM:

John: Reading the last issue of the (sadly, defunct as of Sunday) Drive-In Fan Club Journal, there's a profile of the "Boulevard Drive-In" in Kansas City, which proudly boasts on the sign "World's First Digital Drive-In". Not sure why, though there has been talk lately of a "Dolby Certified Virtual Surround" which takes digital signal, splits to two channels and then "fakes it" I guess. They run FM and speakers. Should my own outdoor get built, I'll give you guys a call ("World's First Kodak-approved DI!). I certainly plan on a small enough screen to reach good light levels.

Another lesson to owners of ANY business. Wes Neal of the Boulevard patrols the grounds for trash. "Even one gum wrapper makes the place look trashy to me." Nobody ever went out of business because they were too clean and the service was too good!

Posted by John Walsh (Member # 168) on 12-30-2000, 12:04 AM:

Only a few more comments for Chris ....
See if you can get a picture of the blower for the Simplex, and see if a filter could be mounted. If you have a few bucks, get some optical glass for the port window- that way you can have the blower without worring about bugs.

I used several different kinds of water tanks/pumps that were supplied for our Simplexs. One was a blue plastic tank with a submersible pump. The other was a steel tank with a motor on the outside (on top) and a shaft down to a brass impeller below.

The blue plastic tank design sealed completely (the lid was locked down by a round steel ring.) This prevented water from evaporating. However, we went through *many* submersible pumps- they'd only last about a year; then die.

The steel tank (it's painted the same as the projector) does not have a sealed top. Also, there is a hole on the side to prevent overfilling it. Water evaporates out of it, so you have to keep filling it every month or so.

You probably know this, but don't forget to only use distilled water and add some kind of anti-freeze in case it gets too cold.

The best tank/pump ever was the Ashcraft.

Posted by Dennis Atkinson (Member # 345) on 12-30-2000, 07:49 AM:

Wouldn't be easier to use a antifreeze with some water rather than water with a little antifreeze? How fast does antifreeze evaporate?

I have seen fresh water lines to the head then to the carbon arc jaws then down the drain. Of course water was cheaper then.

Posted by Gordon McLeod (Member # 33) on 12-30-2000, 09:28 AM:

eventually the antifreeze turns to a jelly
I usually just get a large plastic garbage pail and put a submersable lawn fountain pump in it
The best circulator I ever used was built by atlantic audiovisual for the DP70 at Ont Place
The hold 1 gallon of water with a submersable pump in it and on the top is a radiator from a automatic transmission with a fan behind it
at 7+K the gate is always cold to touch

Posted by Steve Guttag (Member # 268) on 12-30-2000, 12:26 PM:

I now use straight distilled water. Cost/year is cheap...easily replinished and can be dumped down the drain. I don't recommend antifreeze as it is a hazard for dumping and always seems to sludge up the lines...Don't use tap water or mineral water because they too will clog up the lines.

The best way though is filtered city water...always cold.

Steve

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"Old projectionists never die, they just changeover!"

Posted by Jerry Chase (Member # 660) on 12-30-2000, 04:23 PM:

"The best way though is filtered city water...always cold."

Heh. Never been to South Florida, eh?
Somedays I can p... colder than the water here.

We had Noreclos with water cooled gates at one theatre. We replaced the metal cans with plastic trash barrels when those rusted out, and when the circulator motor got noisy we junked the water cooling.

"If you can't wear welders gloves while threading, you aren't a _real_ projectionist..."

Posted by Steve Guttag (Member # 268) on 12-30-2000, 04:28 PM:

>>"Heh. Never been to South Florida, eh?"<<

Yeah but do you Florida types clean the "chads" out of your splicers?

Steve

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"Old projectionists never die, they just changeover!"

Posted by Randy Stankey (Member # 64) on 12-30-2000, 09:57 PM:

I've always had good luck using plain "city water" in the cooling drums. The number one thing is to get the clorine out. I just fill up a big (clean) trash barrel with water and let it sit out for a couple of weeks. When you can't detect any clorine smell / taste, let it go for a while longer. (How 'bout using a swimming pool test kit?)

As far as antifreeze. Use the minimum amount. Actually, antifreeze isn't so much for the "antifreeze" qualities but more of a preservative. Keeps the water from getting scummy. (as quicly)

I've been using 1 gallon of antifreeze to 5 gallons of water. You could probably get away with 6 gallons or more. Just enough to make the water green. That's all.

As to dosposal. It's okay to flush antifreeze down the toilet. (Unless there's a local law against it.) Most sewage treatment plants can handle it in limited quantities. Read the back of the bottle. It says that's what you should do if you can't take it in to be recycled.

Posted by John Pytlak (Member # 331) on 12-31-2000, 11:09 AM:

At the Grandview Drive-In, we always drained and blew out the water lines for the winter. With a recirculator, some sort of corrosion inhibitor and algaecide should be used --- a small amount of ethylene glycol antifreeze does both.

Posted by Ari Nordström (Member # 288) on 01-03-2001, 02:12 PM:

We use filtered tap water. We installed the filter (something a plumber recommended to us, actually) after having to pick apart and clean the lines about once a month or so...

Posted by John T. Mellor (Member # 468) on 01-03-2001, 03:42 PM:

After runnig all kinds of equipment and problems of focus , heat distortion and film damage it is obvious that all of the discussion so far people have varring ideas on what to do to keepthe film and projector cool .One of the Drive ins that I worked had Simplex XL's with Perless Hycandesents [Carbon arc] We ran them at 190 to 210 amps If you didn't water cool the gate and lamp and add the glass heat filters and blowers it didn't take long to destroy film let alone redo your fingerprints.
I would advise anyone that has high wattage lamps to use all the methouds that they can to keep the projector and film from any damage from the heat generated.
FYI even thought the drive in fan club has decided to stop the owners association is still alive and well . I currently an the vice president till March . We are holding our metting of the United Drive in Theatre Owners association In Kissimee Fla. In Febuary. If anyone needs info. E-Mail me at johnm816@juno.com

Have a Great New Year
John

Posted by Chris Erwin (Member # 176) on 01-03-2001, 06:30 PM:

John M. :

I'll see ya there!!

Fellow UDITOA Member...
Chris

Posted by Larry Shaw (Member # 388) on 01-10-2001, 03:07 PM:

Kinoton's circulators are actually coolers, with freon-style refrigeration systems and thermostats. Of course the typical booth circulator becomes a "hot water relocation system" after a short bit of operation. The old Ashcraft circulators had a coil of copper tubing and a fan: poor, but better than nothing.

Posted by Mark Gulbrandsen (Member # 72) on 01-10-2001, 04:46 PM:

Larry, Thats a great idea. Its about time someone came up with that type of cooler. What do they cost? I always hated the hot water circulation tanks.
Mark

Posted by John Walsh (Member # 168) on 01-10-2001, 08:40 PM:

Isn't an actual cooling system overkill? (I'm asking; not complaining!) I mean, you are just trying to get the gate temperature down to a reasonable 90-100'F or so.

I love sexy-fancy equipment, but I would think such a system would not make much difference in picture quality for the majority of theaters, which run 4K or less. Also, it's going to be much more expensive that what a regular water-cooling system costs, in addition to more maintaince (which most theaters also lack.)

Again, not trying to negative, but it seems like a system for "special" theaters, not your regular multiplex.

Posted by Pat Moore (Member # 380) on 01-10-2001, 10:47 PM:

I've got to say that I've never seen water in these standard recirculators even get past the tepid stage, let alone warm enough to brew tea. I've seen quite a number of locations using one circulator to cool two single projectors with platters in close proximity to each other.

Refrigerant cooling would seem just a bit overkill to me. If that's needed to keep the trap operationally cool, then there has to be something else in the optical system that's getting really, really hot. Even the high-powered 870 systems we've built with 10kw behind them don't go that far.

Pat

Posted by Gordon McLeod (Member # 33) on 01-11-2001, 12:38 PM:

Our circuilators use a transmission radiator to act as a heat exchanger to remove the heat
A few years ago we did a twin 70mm 3d installation useing 7K lamps and we used the century circulators and after 20min the water was to hot to put your hand in.
In the first ToddAo install at the rivoli they had a chiller unit to cool the traps with the gertner ventarcs

Posted by Mark Gulbrandsen (Member # 72) on 01-11-2001, 03:16 PM:

In most presently available circulators I have found that the water temperature just keeps climbing till it does get too hot to put your hand in. With lamps larger than 7KW Tea should be easily possible after just three shows! Presently available circulator systems are woefully inadaquate with anything over a 3K lamp on most projectors so the existance of the Kinoton circulator is good news. Its an easy modification to install a small radiator and fan. This helps out and thats what allot of people do.
Mark

Posted by Chris Erwin (Member # 176) on 01-11-2001, 03:52 PM:

The fan/radiator combo...besides the ol' Ashcraft units (what we used where I used to work-till it went bad)are there any produced units for sale or is it Rube Goldburg time...A time honored tradition in this field...

--Chris

Posted by Mark Gulbrandsen (Member # 72) on 01-11-2001, 04:06 PM:

Chris, Its pretty much Rube Goldberg for that. Strong's circulator, which is the only other commercial unit other than the Kinoton that I know of is just that and no aux cooling.
Actually a pretty nice circulator, even better than the Ashcraft can be made fairly inexpensively.
Mark @ GTS

Posted by Gordon McLeod (Member # 33) on 01-11-2001, 09:31 PM:

For many years the now defunked Atlantic Audio Visual produced the one I have with the radiators on the top
Apperatntly they a re a copy of the mole richardson ones used in the UK maybe Dick or Ben are familiar with the original UK design

Posted by John Wilson (Member # 269) on 01-12-2001, 12:58 AM:

For the first 9 years of its 'new' life, the cinema I was chief at ran its cooling water straight through the JJ's and down the sink. When I pointed out that this was very much a no-no and suggested a tank of sorts to recycle the water, they agreed and I had our plumber make me one.

This was a piece of ART man! He was (is) a big fan of H.G. Welles and what he made was something right out of one of his novels. There were tubes (lots of tubes) and bottles and fans and lights and at the end of it all we continually ran at temperatures of 50 to 60 degrees F. Even on 70mm in one screen and 35mm in another both running from the same unit.

The cost of the unit came to over $5,000 and they paid it because they had approved it prior and we had been given what we asked for. They were also...well...stupid.

Of course, I simply didn't want the $300 version. I wanted something that looked good too. The fact the 'upper' management were all morons and had happily paid for it added to my enjoyment of my new and expensive acquisition every time I walked into the booth and saw it. I had it mounted on the wall so that anyone who walked into the booth saw the unit from H.G. first. I got more conversations about that than the huge JJ on a pedestal!

------------------
"Awfully un-sporting of me...I know, but what the hey! I've got to have some fun!"
Daffy Duck.

Posted by Barry Floyd (Member # 385) on 01-12-2001, 07:18 AM:

I've got two of the old "Ashcraft Water Coolers" with the coiled copper tubing on the top. Both are in need of some serious cleaning and de-scaling. It's kind of obvious the former owner ran straight tap water through them. They were used with a pair of Ashcraft "Core-lite" lamphouses.

I've checked and can get new motors for them through Grainger. Would they be worth repairing and restoring or just junk'em and use the plastic garbage pail and a submersible pump?

Posted by Randy Bowden (Member # 587) on 01-12-2001, 04:07 PM:

Personally I would not bother with water cooling a simplex unless you should happen to develope problems. All the ACT 3 installs that I did were a 4K bulb NO water cooling. Just make sure the bulb is focused proper and the lamp house in good alignment.

Posted by John Walsh (Member # 168) on 01-12-2001, 11:29 PM:

Personally, I liked the Ashcraft water circulators. I thought they were well designed for their purpose, and are still useful. So, I would at least try to fix them rather then replace.

Admittedly, the last one made must about 30 years old now. I've noticed that the tanks on some of them start to rust through. So, whether it's worth it to fix them or not depends on what's wrong.

Posted by Mark Gulbrandsen (Member # 72) on 01-12-2001, 11:40 PM:

If you use an old Ashcan recirculator just put two trash can bags in it before adding the coolant. No worry about leaks then.
Mark

Posted by Larry Shaw (Member # 388) on 01-23-2001, 02:24 PM:

Mark,

Sorry for the delay, price is about $1,400. One is at Seattle Cinerama. We typically set the thermostat around 55 deg. F.

-Larry

Posted by Mark Gulbrandsen (Member # 72) on 01-23-2001, 08:06 PM:

Hi Larry,
That is certainly reasonable for what it is and does!! I certainly will keep that one in mind for my next high power project. Considering what a Standard circulator goes for these days buying anything but the Kinoton circulator would be a waste of $$.

Pat,
If you run a high wattage lamp on a JJ for more than several shows the Strong Circulator, since it is literally a closed system, will just keep getting hotter and hotter and hotter.....till it gets to be coffee time! I have actually seen the water/antifreze get a bit steamy. Some projectors water systems are more efficient at heating the water than others. A DP-70 and a JJ for instance have pretty efficient cooling so the water temp rises rapidly.
Mark @ GTS