Depressurize a xenon arc lamp? - Page 1
Forum section: electronics / general

author: cjep
author_rank: Newbie
timestamp: January 29, 2016, 03:25:18 am
content: I want to depressurize a 7 kW xenon arc lamp bulb (15 bar pressure) but I'm not sure how to do it safely. I'm thinking about putting it in a drill press and drilling it through its protective plastic housing but I don't know if that's the best. Is there a way to do this without it blowing and has anyone done this that can share any tips?

author: cvanc
author_rank: Frequent Contributor
timestamp: January 29, 2016, 03:42:37 am
content: Find the manufacturer online and download the data sheet and MSDS. One or both should have specific info on how to vent the lamp. Be careful, I deal with smaller xenon lamps than yours and they can really go boom. DO NOT invent your own method of venting...

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 29, 2016, 05:15:27 am
content: I have to wonder if there's a xenon recycling service... yes, it stays in the terrestrial atmosphere, but it's at such low concentration, it's not terribly cheap stuff...Tim

author: Brumby
author_rank: Unknown
timestamp: January 29, 2016, 12:23:10 pm
content: 15 bar is not to be messed with - especially with glass shards as the shrapnel.Create a weakness in the glass envelope and that thing will explode.

author: amyk
author_rank: Super Contributor
timestamp: January 29, 2016, 12:36:33 pm
content: It makes me wonder how they got the pressure into them in the first place, but this might be a way of releasing it:Put it in a pressure vessel that can withstand 15 bar, pressurise it (so that the pressure inside and outside are nearly equal), make hole, slowly depressurise.Edit: 15 bar is a little over 200psi, which is notthathigh of a pressure for things like steel tanks, although still quite scary to work with...

author: tesla500
author_rank: Regular Contributor
timestamp: January 29, 2016, 08:08:53 pm
content: To fill these lamps, they cool the bulb with liquid nitrogen, pour in liquid xenon, then seal off the pip while the bulb is still cold and the xenon is liquid. When it warms up the xenon evaporates and pressurizes the lamp.My friend works in a movie theater, they just put them in their case and drop them to depressurize them before putting the remains in the trash. These are one of the few types of arc lamps that don't have any hazardous materials.

author: TheWelly888
author_rank: Frequent Contributor
timestamp: January 29, 2016, 08:23:44 pm
content: At work I sometimes change the Xenon arc lamp used in endoscopy illumination. The metal part of the lamp housing has a small closed off tube about 3mm diameter and 5mm long sticking out. That can be cut with a hacksaw until you hear the gas being released, then you can just treat it like an ordinary lightbulb.There may be something like that on your lamp.

author: Supercharged
author_rank: Regular Contributor
timestamp: January 29, 2016, 08:40:35 pm
content: It might not be the safest or correct way, but defenetly the funnyest:tape a small explosive charge (e.g. from some firework) onto it and detonate it from a safe but enjoyable distance

author: m98
author_rank: Frequent Contributor
timestamp: February 04, 2016, 05:25:37 pm
content: What about shooting it with a sniper gun from a safe distance?

author: chris_leyson
author_rank: Super Contributor
timestamp: February 04, 2016, 05:35:16 pm
content: At least Xenon doesn't pose any toxicology risks, it is sometimes used as an anaethsetic, unlike neon which is an asphyxiant.

author: djQUAN
author_rank: Frequent Contributor
timestamp: February 04, 2016, 05:45:04 pm
content: Photonic induction showed how in one of his vids, around the 9 minute mark.

author: Stray Electron
author_rank: Super Contributor
timestamp: February 05, 2016, 03:28:12 am
content: Quote from: Supercharged on January 29, 2016, 08:40:35 pmA friend of mine actually holds the US Patent for doing something very similar to that in air bags. ULTRA fast inflation! They use little tenny, tiny, detonators that were originally made for US military. IIRC they only contain about .09 grams of explosive. All you have to do is to give the pressurized diaphram a shock and it will instantly rupture.I'm not sure that a fire cracker would produce a sharp enough shock but I'll bet that a primer from rifle cartridge would if you could find a way to ignite it at a safe distance. When he and I were kids we actually tried things like this. But not today! You'd end up in jail faster than you could say DHS!

author: cjep
author_rank: Newbie
timestamp: February 09, 2016, 12:10:15 am
content: I actually want to save the glass bulb for display this time so I wonder if that's even possible to do.I always wear protective gear handling these and have probably destroyed 40 or so the last couple of years (we have to before we get rid of them), mostly the safe way throwing it to the ground in the protective casing and sometimes stupid ways with air guns and stuff like that.It's a Ushio DXL-70BA if anyone wonders.

author: TheWelly888
author_rank: Frequent Contributor
timestamp: February 11, 2016, 01:34:33 pm
content: ^^There may be something in the metal contacts housing or on whatever is hidden by the gloves that gives access to the xenon gas.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 11, 2016, 02:00:42 pm
content: Dremel with diamond cutting wheel perhaps, with suitable explosion protection of course!

author: KM4FER
author_rank: Regular Contributor
timestamp: February 11, 2016, 02:59:09 pm
content: The post about how the high pressure xenon tubes are made gave me an idea.If we consider xenon to be near an ideal gas then maybe we could use the ideal gas law to lower the pressure making the process less dangerous.Since the pressure inside the tube is a direct function of temperatureP = nRT/Vthen by lowering the temperature we can lower the pressure.If at room temperature, 24C or 24 + 273 = 297K, the pressure is about 200 bar then cooling the bulb in a dry ice alcohol bath to -78C, or 195K would reduce the pressure to 195/273 * 200 = 143 bar. Still dangerous.Now if you had access to liquid nitrogen then the pressure could be reduced to 77/297 * 200 = 52 bar. Much better.earl...

author: amyk
author_rank: Super Contributor
timestamp: February 12, 2016, 12:10:14 pm
content: The problem with just making a hole at room temperature is like popping a balloon - the pressure is so high that any small defect in the envelope rapidly gets forced apart by the gas trying to escape.Using the same equation with the numbers the OP has posted (15 bar at room temperature) gives ~3.9 bar for the liquid nitrogen case, which is incorrect because xenon becomes solid before that. The question then becomes how to cool it to that temperature without inducing thermal stress, and how to open it once it gets to that temperature (the glass will becomeverybrittle)I still think increasing and decreasing the pressure of the outside is easier than trying to cool it.

author: KM4FER
author_rank: Regular Contributor
timestamp: February 12, 2016, 12:52:59 pm
content: OOPs, Sorry about the 200 bar vs 200 psi mixup. Brain didn't fully engage.What is the bulb made of? Is it borosilicate glass or maybe fused quartz?Knowing this would help in determining what is needed to cut/drill it and how thermal conductive it is.earl...

author: Brumby
author_rank: Unknown
timestamp: February 12, 2016, 02:07:24 pm
content: I was wondering if you could find a spot where you could set up an arc and leave that to erode a hole through the envelope. You know - the sort of thing they warn you NOT to do with a plasma ball.

author: TerraHertz
author_rank: Super Contributor
timestamp: February 22, 2016, 02:07:26 pm
content: Trying to get the Xenon out without breaking the bulb, is almost the same problem as I have. I'd like to salvage the Xenon gas from about 10 big lamps I have, and end up with the Xenon, uncontaminated, in a pressure vessel. I have some suitable gas storage containers (see pic) but how to go from A to B ... I have no idea. Well, not yet.Freezing the Xenon with liquid nitrogen seems like it might be useful. But then making a hole in the glass, and letting the Xenon evaporate and escape, into a previously evacuated space, without mixing with the nitrogen, then pumping... oh hey, if that pressure sphere was cooled with liquid nitrogen, the Xenon evaporating from the bulb would re-freeze in the tank.Hmm...

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: February 22, 2016, 10:25:08 pm
content: Quote from: blueskull on February 22, 2016, 09:38:46 pm+1 this one.You can add metal balls and crush multiple bulbs at once!

author: chris_leyson
author_rank: Super Contributor
timestamp: February 22, 2016, 10:34:00 pm
content: That would be a cremulator then with the added metal balls, wouldn't it be cheaper to just buy Xenon ?

author: Alexei.Polkhanov
author_rank: Frequent Contributor
timestamp: February 22, 2016, 11:20:42 pm
content: Water!No need for vacuum pump. I forgot how we do it in chemistry - instead of pumping out air upside down container filled with water can be used to prevent contamination of gas by air. Bulbs will have to be broken up while submerged in water directly below the bell. You start with big container completely filled with water and turned upside down and then pump out gas with a tube as it appears on top.

author: chris_leyson
author_rank: Super Contributor
timestamp: February 22, 2016, 11:32:38 pm
content: Nice one Alexeiwater seal, old school, at least someone thinking physics

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 23, 2016, 02:23:31 am
content: Mind that the xenon is under pressure, so you'll just get a mess (of water and maybe a little glass) if you do it in open air. You'd need a sealed container, but indeed, with enough shaking, the xenon and glass will part ways and settle to opposite ends of the container.Tim

author: TerraHertz
author_rank: Super Contributor
timestamp: February 23, 2016, 03:08:42 am
content: Quote from: blueskull on February 22, 2016, 09:38:46 pmI like the way you just handwave "pressure vessel" and "high pressure pump". Neither of which are easy. Also that system can't scavenge all the Xenon, and will contaminate it as well. Since high pressure gas transfer pumps (which cost thousands new btw) are not vacuum pumps, and are not generally designed for high purity gas transfer.Even the less difficult case of wanting to transfer high pressure oxygen, nitrogen, argon, etc in 'welding gas' rough purity from one pressure cylinder to another using a high pressure transfer pump is not easy - doubly so when you can only afford 2nd-hand or scavenged gear.The beauty of freezing, sublimating and re-freezing xenon from one container to another, is no pump, and thus no contamination. Also getting virtually all of it.Still not easy. I won't be surprised if I never manage this. Though it's a sub-case of the general problem of transferring smallish amounts of precise gas mixes at lowish pressures, which I do need to solve. For something...Quote from: Alexei.Polkhanov on February 22, 2016, 11:20:42 pmNo, this is just hopeless. Very high water vapor contamination, and also cannot deal with anything like the pressures involved.Even with all-metal chambers and plumbing, the hardware has to be baked out at several hundred degrees C, just to remove water vapor and other gas atoms that always exist on all surfaces that have been exposed to air.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 23, 2016, 08:18:52 pm
content: Quote from: TerraHertz on February 23, 2016, 03:08:42 amWell, okay then. . . ....Just how puredoyou need it, and just how pure do you think the gas inside is, in the first place? I mean numbers. Give a percentage.If your needs (and expectations) are such that, any little fingerprint or adsorbed water, on the outside of the bulb, is fatal, and you don't want to bake things out (because, reasons?), then you're screwed, period.I would perhaps recommend a cold trap (not as cold as liquid xenon), and maybe some gettering. But I'm beginning to think recommending anything at all is wasted effort.Tim

author: jwm_
author_rank: Frequent Contributor
timestamp: February 24, 2016, 12:30:46 am
content: Seeing as how the xenon recovered as a side effect of lox production is usually just vented off as waste, I doubt it is worth recovering from a lamp. There just isn't much demand for large quantities of it outside ion thrusters. (I have one on my desktop that liquifies air just great). Some things are expensive _because_ there is little demand for it.

author: TerraHertz
author_rank: Super Contributor
timestamp: February 24, 2016, 08:21:28 am
content: Quote from: jwm_ on February 24, 2016, 12:30:46 amWell that led to an interesting but frustrating hour of googling. Plenty of companies that sell pure and mixed gases, but did I find even one that has prices online? For _anything_? No.Couple of relevant quotes:"It takes approximately ten million cubic metres of air to obtain one cubic metre of Xenon. A crude blend of rare gas mixture is taken to a purification centre for rare gases where it is then separated, refined and purified up to grades of 99.999% purity.""At less than 100 ppb, xenon is one of the most rare natural gas components in our atmosphere."

author: station240
author_rank: Unknown
timestamp: February 24, 2016, 06:06:01 pm
content: If there isn't a nub to break off to release the gas, then perhaps a small blow torch hot enough to burn a hole in the glass would work. eg get the blowtorch working, put it next to the bulb and run.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 24, 2016, 07:15:11 pm
content: Well, that's how they're made... Fused quartz isn't exactly fragile, it can be quenched from yellow hot to room temp without cracking.More a problem is that you need an oxyhydrogen flame to melt it. Or maybe a carbon arc.Tim

author: TerraHertz
author_rank: Super Contributor
timestamp: February 26, 2016, 10:54:25 pm
content: While I was googling for xenon prices, I found two local companies I'd never heard of that sell precision gases - pure and calibrated mixes. Both companies apparently with local gas refining facilities. (Well, Port Kembla isn't quite local for me, but near enough.)No price lists, but they do have contact phone numbers.I'll try phoning them next week, both for prices, and to see what they have to say about the xenon in these large arc lamps, and if there's any known practical method to recover it.