Hot! Hot! Hot!
in [Design]
|
Prev: SMPS "S" terminals & V adj.
Next: usenet
From: ian field on 22 May 2010 10:52 "Royston Vasey" <royston(a)vasey.com> wrote in message news:28OdnfidC8DaKmrWnZ2dnUVZ_qKdnZ2d(a)westnet.com.au... > > "Archimedes' Lever" <OneBigLever(a)InfiniteSeries.Org> wrote in message > news:9gafv51pi6vanal3frd7ji3eqnukvkp5cg(a)4ax.com... >> On Fri, 21 May 2010 21:48:03 +0100, "ian field" >> <gangprobing.alien(a)ntlworld.com> wrote: >> >>> >>>"Bob Eld" <nsmontassoc(a)yahoo.com> wrote in message >>>news:ht6ima$hj1$1(a)news.eternal-september.org... >>>> >>>> <lektric.dan(a)gmail.com> wrote in message >>>> news:6cb52649-d4f5-4c75-aff8-5d8d93340791(a)j9g2000vbp.googlegroups.com... >>>>> (no, this isn't spam...) >>>>> My boss came to me with another brain-stretching problem. We're >>>>> looking at designs for a new microreactor. We need to heat a section >>>>> of 1/2" dia. quartz tubing to 1000 oC in 1 second (heating zone is >>>>> about 1 inch. How to go about this? Inductive coil? Radiant quartz >>>>> lamps? RF? Microwave? What else is out there? Would prefer >>>>> commercial to build-it-ourselves. >>>>> (the material that will be going through the reactor is the same >>>>> finely ground organic material that resembles pepper or oregano). >>>> >>>> A thousand deg C in one second?? Have you calculated the power to do >>>> that? >>>> What's in the tube. Pepper or oregano? Organics will just carbonize. >>>> You >>>> need to be more specific. Obviousy methods that require electrical >>>> conductivity wont work well if at all. >>> >>>Don't know about quarz, but glass becomes conductive at red heat. >>> >> Cite! > > > http://www.youtube.com/watch?v=RYdaYQuEhy4 At one time I was making my living repairing microwaves - and developing ever more interesting ways to check that output was up to scratch. One experiment was to microwave a 1/4 x 1&1/4 glass fuse that had blown violently and metalised the inside of the glass tube. That melted without starting it off with a blowtorch.
From: Archimedes' Lever on 22 May 2010 12:07 On Sat, 22 May 2010 18:51:48 +0800, "Royston Vasey" <royston(a)vasey.com> wrote: > >"Archimedes' Lever" <OneBigLever(a)InfiniteSeries.Org> wrote in message >news:9gafv51pi6vanal3frd7ji3eqnukvkp5cg(a)4ax.com... >> On Fri, 21 May 2010 21:48:03 +0100, "ian field" >> <gangprobing.alien(a)ntlworld.com> wrote: >> >>> >>>"Bob Eld" <nsmontassoc(a)yahoo.com> wrote in message >>>news:ht6ima$hj1$1(a)news.eternal-september.org... >>>> >>>> <lektric.dan(a)gmail.com> wrote in message >>>> news:6cb52649-d4f5-4c75-aff8-5d8d93340791(a)j9g2000vbp.googlegroups.com... >>>>> (no, this isn't spam...) >>>>> My boss came to me with another brain-stretching problem. We're >>>>> looking at designs for a new microreactor. We need to heat a section >>>>> of 1/2" dia. quartz tubing to 1000 oC in 1 second (heating zone is >>>>> about 1 inch. How to go about this? Inductive coil? Radiant quartz >>>>> lamps? RF? Microwave? What else is out there? Would prefer >>>>> commercial to build-it-ourselves. >>>>> (the material that will be going through the reactor is the same >>>>> finely ground organic material that resembles pepper or oregano). >>>> >>>> A thousand deg C in one second?? Have you calculated the power to do >>>> that? >>>> What's in the tube. Pepper or oregano? Organics will just carbonize. You >>>> need to be more specific. Obviousy methods that require electrical >>>> conductivity wont work well if at all. >>> >>>Don't know about quarz, but glass becomes conductive at red heat. >>> >> Cite! > > >http://www.youtube.com/watch?v=RYdaYQuEhy4 > > It was heated by hysteresis, which is the action by which a microwave works. The was no electrical current in the glass. IDIOTS!
From: ian field on 22 May 2010 12:22 "Archimedes' Lever" <OneBigLever(a)InfiniteSeries.Org> wrote in message news:p70gv51219macsdn60f77n0ondedi8p903(a)4ax.com... > On Sat, 22 May 2010 18:51:48 +0800, "Royston Vasey" <royston(a)vasey.com> > wrote: > >> >>"Archimedes' Lever" <OneBigLever(a)InfiniteSeries.Org> wrote in message >>news:9gafv51pi6vanal3frd7ji3eqnukvkp5cg(a)4ax.com... >>> On Fri, 21 May 2010 21:48:03 +0100, "ian field" >>> <gangprobing.alien(a)ntlworld.com> wrote: >>> >>>> >>>>"Bob Eld" <nsmontassoc(a)yahoo.com> wrote in message >>>>news:ht6ima$hj1$1(a)news.eternal-september.org... >>>>> >>>>> <lektric.dan(a)gmail.com> wrote in message >>>>> news:6cb52649-d4f5-4c75-aff8-5d8d93340791(a)j9g2000vbp.googlegroups.com... >>>>>> (no, this isn't spam...) >>>>>> My boss came to me with another brain-stretching problem. We're >>>>>> looking at designs for a new microreactor. We need to heat a section >>>>>> of 1/2" dia. quartz tubing to 1000 oC in 1 second (heating zone is >>>>>> about 1 inch. How to go about this? Inductive coil? Radiant quartz >>>>>> lamps? RF? Microwave? What else is out there? Would prefer >>>>>> commercial to build-it-ourselves. >>>>>> (the material that will be going through the reactor is the same >>>>>> finely ground organic material that resembles pepper or oregano). >>>>> >>>>> A thousand deg C in one second?? Have you calculated the power to do >>>>> that? >>>>> What's in the tube. Pepper or oregano? Organics will just carbonize. >>>>> You >>>>> need to be more specific. Obviousy methods that require electrical >>>>> conductivity wont work well if at all. >>>> >>>>Don't know about quarz, but glass becomes conductive at red heat. >>>> >>> Cite! >> >> >>http://www.youtube.com/watch?v=RYdaYQuEhy4 >> >> > > It was heated by hysteresis, which is the action by which a microwave > works. > > The was no electrical current in the glass. > > IDIOTS! In my first year at college the lecturer demonstrated a glass rod placed on a pair of metal trestles that were connected in series with a lightbulb, when heated red hot with a blowtorch the glass rod became conductive and the lightbulb lit. Therefore you are the idiot.
From: Martin Brown on 24 May 2010 03:44
On 21/05/2010 22:25, Bob Eld wrote: > <lektric.dan(a)gmail.com> wrote in message > news:d43e9f5c-c0b6-478b-83c1-597cb0f7ef1e(a)m4g2000vbl.googlegroups.com... > On May 21, 1:16 pm, "Bob Eld"<nsmontas...(a)yahoo.com> wrote: > >> >> A thousand deg C in one second?? Have you calculated the power to do that? > > Yep. A "metric boatload" depending upon method and effeciency. That is a bit fast and likely to cause you trouble...steam or other solvent explosion is a real possibility if the sudden pressure increase cannot escape. > >> What's in the tube. Pepper or oregano? > > "A finely ground organic substance like pepper or oregano" is all I > can tell you in a public newsgroup. It's legal, if that's what you're > thinking. > >> Organics will just carbonize. > > That's kinda the idea. Actually, they will pyrolyze (decompose by > heating in the absence of oxygen). In that case you probably want to look at existing kit that includes the keywords electrothermal vapourisation and/or pyrolysis. It is a recognised analytical technique although emphasis is usually on a sequential controlled rate of temperature increase and plateaux of temperature to drive off first any water and then whatever organics and finally metals are to be analysed. Blatting things at 1000C immediately might not be so smart if they are even slightly damp with solvent. Most of them seemed to use a graphitic carbon sample tube in an inert argon atmosphere and carrier gas. PSU has to be pretty chunky and the hefty current carrying cables flex amusingly when the thing is at top whack. There will be stuff in the patent literature for this. Regards, Martin Brown |