Film-Tech Forum ARCHIVE: Kinoton lamphouses

This is topic Kinoton lamphouses - reflectors flaking in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Christopher Seo (Member # 7) on 03-01-2007, 02:18 PM:

I have a pair of Kinoton Universal lamphouses (marked "2-7KW") in a changeover setup at my theatre. After about two years of operation, the mirror coatings in both are failing, as the image of one of them shows. Both mirrors look roughly the same, particularly in that the flaking occurs only in the top half.

Background: I was told that airflow was measured at 750 cfm, which is supposed to be more than adequate (I couldn't find the specs in the lamphouse manual). Each lamphouse has its own roof exhaust fan. Bulbs are Osram 4Ks at roughly 130 A, in the middle of the range for this lamphouse model. There have been no exhaust fan or blower failures, and the booth has good air conditioning.

We run 20 minute reels, so the dousers are closed for half the time the lamps are on, but I assume this is not an issue. Curiously, only the top half of each reflector is flaking. In fact, the heat filter in the front of the lamphouse even appears to be aimed at the top of the reflector.

Has anyone had this problem? Any suggestions or solutions would be appreciated. Thanks in advance.

Posted by John Pytlak (Member # 331) on 03-01-2007, 02:58 PM:

quote: Christopher Seo
Curiously, only the top half of each reflector is flaking. In fact, the heat filter in the front of the lamphouse even appears to be aimed at the top of the reflector.

A dichroic heat filter reflects the infrared (heat) energy. It should be aimed at a heat sink that can dissipate the heat.

Posted by Richard Fowler (Member # 893) on 03-01-2007, 06:09 PM:

Check the accuracy of the lamphouse meter to make sure you are at 130 amperes. High humidity can effect the reflector coating. The interior of the lamphouse has a high temperature fiber sheeting to wick off heat. The dichoric, if properly mounted and oriented in the angled frame should not cause a problem.

Posted by Louis Bornwasser (Member # 3063) on 03-01-2007, 06:44 PM:

750 cfm is very marginal at 2000 watts; at 4 k it is very low. You should have difficulty holding on to your cleaning rag when cleaning the lamphouse. Louis

Posted by Mark Gulbrandsen (Member # 72) on 03-01-2007, 07:33 PM:

Its obvious that you've cooked the reflectors. The top half is flaking because heat rises to the top. I've seen metal reflectors go this way too. I agree with Loius... you have VERY inadaquate airflow!! You need at least double that 750cfm for each of your 4kw lamps. You should shoot who ever told you that 750 was enough and if that 750 is being split between the two call your attorney!

Mark

Posted by Richard Hamilton (Member # 321) on 03-01-2007, 08:42 PM:

Incorrect the CFM is enough, if there was heat damage you will know it by the back of the reflector. Peeling is a result of bad coatings and or improper direct air flow on the bulb and reflector. NOT MY POST.....RICK

[ 03-02-2007, 12:08 AM: Message edited by: Richard Hamilton ]

Posted by Christopher Seo (Member # 7) on 03-01-2007, 08:45 PM:

Everyone, thanks for your responses.

Louis and Mark, it's possible I am misinformed on what the airflow was designed and/or measured to be. And if the airflow were seriously inadequate, would it show up in other ways, i.e. a seriously hot lamphouse exterior (which I have not noticed)?

Posted by Steve Guttag (Member # 268) on 03-01-2007, 10:19 PM:

Impersonator, Whereas the Kinoton Balzer's reflector is glass, it is most unlikely that the back of the reflector will provide any indication of the heat.

There is an 8" fan in the top of the lamphouse that pumps 800cfm out minimum so if the roof exhaust does not draw at least 800cfm, then they are pressurizing the exhaust stack rather than completely exhausting the heat.

It could be the photo but the anode of that lamp (where the seal is) looks discolored (turning yellow-orange) which indicates insufficient exhause...those stems should look the same as when the lamp went in.

As for the flaking...It is possible that both lamps are not aligned properly and excess heat is being focused onto the reflectors but I do tend to think this damage was created when the reflectors were formed. We have suffered through a bad batch of Balzer's reflectors in the past

[ 03-02-2007, 05:49 AM: Message edited by: Steve Guttag ]

Posted by Demetris Thoupis (Member # 833) on 03-02-2007, 02:06 AM:

It might be a 1 to a zilion case that you got a patch of faulty reflectors. As far as I know we have these type of lamphouses in one of the theaters we service and did the installations since 2001 and had no problems with them what so ever.
Demetris

Posted by Pete Naples (Member # 761) on 03-02-2007, 10:15 AM:

I've seen one Kinoton mirror do that. Airflow was good, alignment etc perfect.

The cause it turned out, was somehow the theatre had damaged the reflector coating whilst cleaning, and from a small chink in it's armour, that mess resulted.

Posted by Michael Schaffer (Member # 1204) on 03-04-2007, 05:57 AM:

The trick here is to get an IR thermometer, run the lamphouse for a while, then don the protective mask, switch the lamp off and immediately check with the thermometer for excessive heat areas in the lamphouse/on the mirror/on the end pieces of the lamp. As has been said before, the glass filter has to be aimed directly at the exhaust - that should be a good 45 degree angle - not at the top of the reflector or top of the lamphouse above the reflector.
And, the heat filters have to be installed with the coated side facing the lamp or rather exhaust. The coated side is the side which looks a little shimmery when you look at it from the side. The other side (facing forward/down) is just naked glass.
I would also check the alignment of the entire lamphouse and reflector, to make sure you don't have a twisted alignment here with the reflector at a bad angle and the lamp further up than necessary to make up for that.
BTW, it looks like the front end of the bulb is resting solidly on the front support post. In the Kinoton lamphouse, the support should actually be just below the end piece of the lamp, almost, but not quite touching it. Because the lamp will stretch when hot. This won't cause the problem here, just wanted to mention that.