Film-Tech Forum ARCHIVE: Depressurizing a Xenon Bulb

my profile | my password | search | faq & rules | forum home

»	Film-Tech Forum ARCHIVE » Operations » Film Handlers' Forum » Depressurizing a Xenon Bulb (Page 2)

This topic comprises 2 pages: 1 2

Author

Topic: Depressurizing a Xenon Bulb

Mike Williams
Master Film Handler

Posts: 255
From: Knoxville, TN
Registered: Feb 2002

posted 07-30-2002 09:33 AM

Chad,
If you were to depressurize a bulb at room temperature like that, wouldn't it cloud up?

Or is it that bulbs that have seal failures only cloud up because of the extreme heat produced by the arc?

| IP: Logged

Adam Martin
I'm not even gonna point out the irony.

Posts: 3686
From: Dallas, TX
Registered: Nov 2000

posted 07-30-2002 10:12 AM

I think the clouding is a tungsten oxide formed when the super-heated tungsten cathode and anode react with oxygen. Sometimes it's white and sometimes blue, depending on how many oxygen molecules the tungsten molecules pick up.

| IP: Logged

Dave Macaulay
Film God

Posts: 2321
From: Toronto, Canada
Registered: Apr 2001

posted 07-30-2002 09:20 PM

Ther are a few ways to depressurize the lapm. I'd never thought of drilling one though!
At Imax I used to depressurize 15kW water cooled lamps. The procedure was to put on the blast gear, evacuate the machine shop, and with the bare bulb wrapped in another "flak jacket" so the nipple sticks out, gently introduce said nipple to the fine grindstone wheel.
I had one blow up out of about 10, it really wasn't terrifically dramatic.
When it works properly the gas just hisses out.
There was no fogging or discoloration caused by the degassing.
Unfortunately we found that used lamps that have been depressurized tend to just shatter after a few minutes to a few years.Internal stress in the envelope causes it to shatter into tiny pieces similar to breaking a car door window.

| IP: Logged

Chad Souder
Jedi Master Film Handler

Posts: 962
From: Waterloo, IA, USA
Registered: Feb 2000

posted 07-30-2002 10:57 PM

Don't know much about the science part of it, but I do know that the bulbs didn't cloud up. As far as I know, the bulbs didn't shatter either, but I'll have to check with the recipients for that.

| IP: Logged

Frank Angel
Film God

Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999

posted 07-31-2002 01:55 AM

Chad,

That sure takes a set. You could wrap that thing in a mattress and there would be no way I would have the nerve to stand there and drill a hole in one. I mean, you might tell me a hundred times it won't explode, but man, I would wuss out on you every time. See....that's me handing the drill to the assistant manager and running to the parking lot, yelling behind me -- "Yah, kid, just drill into that bulb; take your time."

| IP: Logged

Dennis J. Losco
Film Handler

Posts: 39
From: Phillipsburg, NJ, USA
Registered: Jul 2002

posted 07-31-2002 07:35 AM

If anybody is interested in display lamps please let me know, especially if you are using the Superior lamp. We can depresurize one of yours or send you one that has been returned for disposal. My suggestion is "don't do this at home". We have sizes from 150watt to 32,000 watt lamps available.
Thanks, Denny
denjr@sqpuv.com www.sqpuv.com

------------------

| IP: Logged

Stephen Furley
Film God

Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002

posted 07-31-2002 10:13 AM

"We have sizes from 150watt to 32,000 watt lamps available"

What would you use a 32k lamp for? Can't be for film projectors, surely; searchlights maybe, or something similar? How big are they? Can I stand a long way away when you strike one? Can I stand even further away if someone tries drilling a hole in one!

| IP: Logged

Dennis J. Losco
Film Handler

Posts: 39
From: Phillipsburg, NJ, USA
Registered: Jul 2002

posted 07-31-2002 10:38 AM

32,000 watt lamps are used by the government for solar simulation. They actually have 16 to 30 of these lamps burning at the same time, all focusing down to one beam which enters a vaccum chamber. They will then test precious metels etc. for space. The lamp is pretty much the same size as a 15kw used for the IMAX projectors. We have a safe mean of depressurizing these lamps but I wouldn't suggest drilling one of these lamps at home. It would make a really loud boom!!! I can email you pictures if you would like. Quick send me an email and I will send them to you.
Thanks,
Denny

------------------
Dennis J. Losco Jr
Superior Quartz Products, Inc.
404 County Road 519
Phillipsburg, NJ 08865
denjr@sqpuv.com http://www.sqpuv.com
Tele: 908-454-1700
Fax 908-454-4154

| IP: Logged

Paul G. Thompson
The Weenie Man

Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000

posted 07-31-2002 08:04 PM

Dennis says "Don't do this at home." I recommend you heed to his advice.

| IP: Logged

Stephen Furley
Film God

Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002

posted 08-01-2002 06:07 AM

"Dennis says "Don't do this at home." I recommend you heed to his advice."

I'm about 6,000km away, and I think that's about as close as I would want to get to one of those things! I was in NJ just a few months ago, I don't think I would have wanted to get that close if I'd known they had things like that there

Dennis, is that thing water cooled, it looks like it has a double skin?

I,ve just had an evil thought; you could connect one of those things up in a room somewhere, wire up the control circuits to a normal light switch. You could give someone a heck of a shock when they turned the lights on!

The brightest lamp I have seen is a 18k HMI, how does this compare to that for light output?

| IP: Logged

David Rigby
Expert Film Handler

Posts: 134
From: Chorlton, Manchester, UK
Registered: May 2002

posted 08-01-2002 06:13 AM

So I'm guessing the rectifier for those 32 bulbs isn't all that portable then?

David

| IP: Logged

Bernard Tonks
Jedi Master Film Handler

Posts: 619
From: Cranleigh, Surrey, England
Registered: Apr 2001

posted 08-01-2002 06:55 AM

All very interesting Dennis, and the pictures.

Is it possible for you to tell us the average life of the 32kw bulb, and the cost. Also a 15kw used for Imax, as I have often wondered. Thanks.

| IP: Logged

Dennis J. Losco
Film Handler

Posts: 39
From: Phillipsburg, NJ, USA
Registered: Jul 2002

posted 08-01-2002 07:31 AM

Yes, this is a liquid cooled lamp. Currently we manufacture a 12,15, 20 and a 32kw. And to give you an idea of how bright they are, the next time you see pictures of the space shuttle keep in mind that our 20 kw lamps are used to illuminate it. Recently they have been swaping them out for 10kw air cooled lamps though, but they have been giving up life. The 15kw lamps will last anywhere from 1000 hours to 1500 hours and the 32kw will last about 400-500 hours. Pricing!!!!! Well lets say they begin at $5600 each for the 15's and as much as $7000 for the 32's. All of this technology was gained when we purchased the liquid cooled division of Durotest. Yea it has been really exciting and really went nice with our xenon cinema line of air cooled lamps. Hey thanks for the interest guys!!
Denny

------------------
Dennis J. Losco Jr
Superior Quartz Products, Inc.
404 County Road 519
Phillipsburg, NJ 08865
denjr@sqpuv.com
http://www.sqpuv.com
Tele: 908-454-1700
Fax 908-454-4154

| IP: Logged

All times are Central (GMT -6:00)

This topic comprises 2 pages: 1 2

Printer-friendly view of this topic

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.