cheap source of quartz tubes?

Free source of quartz tubes?

I've seen toaster ovens that appear to have <a href="http://en.wikipedia.org/wiki/Fused_quartz" target="_blank">fused quartz</a> <img src="../scipics/_wiki.png" /> tubes surrounding the metallic heating elements.

<strong>More than you ever wanted to learn about commercial lighting:</strong>
At my job, I often replace <a href="http://en.wikipedia.org/wiki/High-intensity_discharge_lamp" target="_blank">HID lamps</a> <img src="../scipics/_wiki.png" /> in <a href="http://www.informinc.org/fact_P3high_bay.php#what" target="_blank">high bay</a> <img src="../scipics/_ext.png" /> fixtures. Most of these <a href="http://en.wikipedia.org/wiki/Lamp_(electrical_component)" target="_blank">lamps</a> <img src="../scipics/_wiki.png" /> (the correct term for a <a href="http://www.techlinea.com/wp/?p=181" target="_blank">'light bulb'</a> <img src="../scipics/_ext.png" /> have an inner fused quartz envelope called an arc tube (see <strong>Fig. I</strong>. These contain most of the harmful metals and halogens inside an unexploded HID lamp. Approximately half the lamps (the ones needing replacement) that I deal with have had the arc tube explode (on a good day, the outer glass envelope remains intact). These partially exploded lamps are collected in designated cardboard drums and are destined for recycling by the lighting supplier (same with <a href="http://en.wikipedia.org/wiki/Fluorescent_lamp" target="_blank">fluorescents</a> <img src="../scipics/_wiki.png" />.

If they've completely exploded, I chuck 'em in the dumpster outside&mdash;since most of the Hg and other 'nasties' have already vaporized into the atmosphere inside the building. I prefer to keep my occupational Hg vapor exposure as low as is feasible. So, my thoughts are why concentrate the vapor inside the barrel or building when it's already destined for release into the environment?

<center><table><tr><td><!--<img src="http://amerilights.com/uploads/misc/pg57_image_hid.jpg" width="300" alt="Figure I" caption="Figure I" />--><img src="../scipics/user:bfesser/HID-Lamp.gif" alt="Figure I" caption="Figure I" /></td></tr><tr><td><strong>Figure I.</strong> Diagram of a typical HID lamp.</td></tr></table></center>

Some of the smaller HID lamps that I deal with in track lighting contain an extra glass component. It's an extra cylindrical tube surrounding the inner envelope (see <strong>Fig. II</strong>. I'm not sure, but I think this tube may also be constructed of fused quartz. When these lamps (with the extra tube) cease to function properly, the arc tube often remains intact. When I replace them, I often wonder if it would be worth it to cut off the outer glass envelope in order to recover the cylindrical glass tube surrounding the arc tube. These tubes are likely too short for most laboratory applications, but does anyone here know if this component is indeed fused quartz?


<center><table><tr><td><img src="http://www.vosslighting.com/storefrontB2BWEB/img/staging/HID/mh_ps_ed28p_cl.gif" width="300" alt="Figure II" caption="Figure II" /></td></tr><tr><td><strong>Figure II.</strong> Photograph of a Philips MP175/BU/12PK.
Note the cylindrical glass tube wrapped in a wire helix.</td></tr></table></center>


<strong>Final personal note:</strong>
I'm very happy that my employer has finally begun to phase out all of the <a href="http://en.wikipedia.org/wiki/Halogen_lamp#Handling_precautions" target="_blank">halogen</a> <img src="../scipics/_wiki.png" />, <a href="http://en.wikipedia.org/wiki/Compact_fluorescent_lamp" target="_blank">compact fluorescent</a> <img src="../scipics/_wiki.png" />, and <a href="http://en.wikipedia.org/wiki/Incandescent_light_bulb" target="_blank">incandescent lamps</a> <img src="../scipics/_wiki.png" />. The new <a href="http://en.wikipedia.org/wiki/LED_lamp" target="_blank">LED lamps</a> <img src="../scipics/_wiki.png" /> are fantastic; longevity, energy consumption, ease of recycling, etc. As an added bonus, I receive less nasty burns and cuts at my day job. Those injuries are now reserved for chemistry.

[edit: the first image has been replaced since this was originally posted, because the original image was hosted externally and disappeared]

[Edited on 7/9/13 by bfesser]

Quote: Originally posted by garage chemist

bfesser, the cylindrical shrouds around the arc tubes in HID lamps are indeed fine transparent quartz. No other glass would stand up to the temperatures so close to the arc tube.

garage chemist, I don't mean to offend, but do you have a source to support this claim? I'd just like to be sure before I put any more effort into this.

If that is indeed the case, I have a free source of as many of these tubes as I can recover. Of course, I would leave the arc tube intact and send it in for proper recycling/disposal. I'm thinking that the best way would be to cut the outer envelope cleanly (at a point where the diameter is just large enough to pull the quartz cylinder out) using the method employed by the gentleman in <a href="http://www.youtube.com/watch?feature=player_detailpage&v=gl-QMuUQhVM#t=263s" target="_blank">this familiar video</a> <img src="../scipics/_ext.png" />.

Procedure outlined:<ol><li>Cut outer envelope at red line.</li><li>Pull entire assembly out of 'bulb'.</li><li>Cut wires as necessary to remove quartz cylinder (highlighted in blue).</li><li>Salvage any useful <a href="http://en.wikipedia.org/wiki/Tungsten" target="_blank">W</a> <img src="../scipics/_wiki.png" /> wire.</li><li>Recycle the arc-tube and <a href="http://en.wikipedia.org/wiki/Getter" target="_blank">getter</a> <img src="../scipics/_wiki.png" />.</li></ol>


I wonder how difficult it would be to fuse these end to end. Should I give it a try?

[hehe, it looks like I had a stutter]

[Edited on 7/9/13 by bfesser]

Quote: Originally posted by bfesser

I wonder how difficult it would be to fuse these end to end. Should I give it a try?

Thank you guys for the input, I'm sure it will prove valuable. I think I'm going to give one of these tubes a shot for an 'easy' pyrolysis, meaning a not really toxic one, although I haven't really decided in one yet.