|
|
This topic comprises 2 pages: 1 2
|
|
Author
|
Topic: Projectors that put electricity back into the grid
|
|
|
|
|
|
|
|
|
|
|
Stephen Furley
Film God
Posts: 3059
From: Coulsdon, Croydon, England
Registered: May 2002
|
posted 10-01-2002 03:59 PM
A fair number of cinemas in the uk, mainly single screen places running small lamps, e.g. 100 or 1600W do not have them vented. One larger example comes to mind, when it was open, the State, Grays, about 2,500 seats I think, had three projectors with Magnarcs, one still carbon, two with 2.5kW xenon conversions, which were not vented, I think these were the largest unvented lamps I have seen. The screen in this place was one of the largest in the country, they could really have used at least 4k. The carbon projector was vented, and I think the two spots and the Brenograph had hoods, but there was quite a strong smell of carbon fumes in the box when they had been running. Why the ducting had been removed from the two xenon projectors I don't know.The David Lean in Croydon, recently built, very small, maybe 50 seats, has a pair of 100W xenons, and these are vented, so it doesn't always go by size.
| IP: Logged
|
|
|
|
Scott Norwood
Film God
Posts: 8146
From: Boston, MA. USA (1774.21 miles northeast of Dallas)
Registered: Jun 99
|
posted 10-01-2002 07:12 PM
I've worked in a booth with a pair of Kinoton FP-30s with 2kw bulbs without ventilation and, surprisingly, the booth didn't get very hot at all. These aren't "normal" 2kw xenons like one would use in a Christie or Strong lamphouse, however; they are physically smaller. Also, Kinoton machines have one switch to control both motor and lamp, so there was only one lamp running at a time.I've also run several booths with two machines with 1kw and/or 500w lamps without ventilation; heat wasn't a major issue there, either. Of course all of these use modern (supposedly) ozone-free xenons. I will soon have a carbon arc Super Trouper followspot (essentially the same thing as a Strong "Utility" lamphouse) running unvented in a large theatre, although it won't be run for more than a few minutes at a time (and, then, only occasionally) and will be on a theatre balcony, not an enclosed booth. I'm not necessarily trying to suggest that any of these setups is optimal, just that the smaller lamps can be run unvented without adverse consequences for the operator, though lamp life probably suffers.
| IP: Logged
|
|
|
|
Frank Angel
Film God
Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999
|
posted 10-01-2002 09:57 PM
First generation xenons, besides being as sensitive to vibrations as nitroglycerin, also produced dangerous levels of ozone, and those were the days of single screen booths. Imagine what the levels would be today with a dozen or more lamphouses running all day long?! Newer generations of xenon lamp design have corrected much of those early problems, which unfortunately has led manufacturers to used the term "ozone free" quite loosely. Even the most modern xenon bulbs are not ozone free, and yes, a single bulb will give off low levels of the gas that is said (by someone) to be harmless, but that's looking at one bulb at a time. Given the nature of multiplex operation, rarely is a single bulb fired in most booths -- there are many of them and the ozone accumulation can be significant if it is not properly vented by a properly designed ventilation system. Some years ago a civil suit was filed in Brooklyn against Cineplex-Odious and the management of the Alpine Theatre here because the venting system was inadequate and always in bad repair with management refusing to address the problem. The union projectionists were getting very ill. OSHA became involved and found very high levels of ozone as well as even more toxic gases. The case was settled, and the ventilation system was upgraded. When a large multiplex is designed with a common booth, the idea of ozone-free bulbs becomes a real issue; proper ventilation needs to be part of the design, not an afterthought. I believe that in NYC the building code for projection booths still requires that if the booth is going to have a ventilation system for the general booth area, it must be a separate system from the projectors which must always be vented. I think that is still on the books, but then again, the requirement for a licensed projectionist to be present in the booth at all times is also still on the books, but its a reg that management pretty much laughs at. Frank
| IP: Logged
|
|
|
|
|
|
|
|
Gerard S. Cohen
Jedi Master Film Handler
Posts: 975
From: Forest Hills, NY, USA
Registered: Sep 2001
|
posted 10-04-2002 03:54 PM
David said:
<<Therefore, by definition, a motor can not act as a generator with any gain in energy.>>True, but there is ongoing research into conserving energy in motor vehicles by utilising the energy of the moving mass during decelleration and braking to generate potential energy stored in batteries. Normally, braking produces heat and is wasteful of the energy it took to overcome inertia at starting and accellerating.
Almost since the invention of motorcars, magnetos, generators and alternators have been used to recharge the battery, driven by the gasoline engine itself. Driving similar generators from the wheels
on decellerating would be a further conservation, if storage of electrical energy permitted the use of electrical motors part time during the use of the vehicle. Perhaps this research, and the frequent announcement that such a vehicle's production is imminent, is what suggested Matthew's posting of this thread?
| IP: Logged
|
|
|
|
|
|
All times are Central (GMT -6:00)
|
This topic comprises 2 pages: 1 2
|
Powered by Infopop Corporation
UBB.classicTM
6.3.1.2
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.
|
Home
But we cursed them on hot summer nights. 
Printer-friendly view of this topic