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From: lektric.dan on 22 May 2010 06:13 On May 21, 10:36 pm, Robert Baer <robertb...(a)localnet.com> wrote: > > You cannot (efficently) heat quartz inductively or with RF of any > type (obviously that includes microwave). Well, no, not directly. There would have to be a heating element on the outside that would actually be heated. They're also kicking around the idea to use a stainless steel tube to be directly inductively heated. I *think* only magnetic-type stainless would work, and I'm not sure about the corrosion resistance of these alloys. > What is left? infra red heaters not unlike the radiant quartz lamps > mentioned or a rather hot flame. > You did not mention some critical parameters: LENGTH of tubing to be > heated, 1" and THICKNESS (or mass) as that 1/2 might be ID or there may be > a rather small bore. I think it will be rather thin wall. The wall thickness will, of course, be determined by the pressure. If the pressure is very high, thos won't work at all because the quartz will soften and blow out. Thermal shock make be a killer issue too.
From: Royston Vasey on 22 May 2010 06:51 "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
From: langwadt on 22 May 2010 09:49 On 22 Maj, 12:13, "lektric....(a)gmail.com" <lektric....(a)gmail.com> wrote: > On May 21, 10:36 pm, Robert Baer <robertb...(a)localnet.com> wrote: > > > > > You cannot (efficently) heat quartz inductively or with RF of any > > type (obviously that includes microwave). > > Well, no, not directly. There would have to be a heating element on > the outside that would actually be heated. They're also kicking > around the idea to use a stainless steel tube to be directly > inductively heated. I *think* only magnetic-type stainless would > work, and I'm not sure about the corrosion resistance of these alloys. > iron isn't magnetic at 1000C. if it is conductive it can be induction heated, induction brazing of copper tubing for example. only a few stainless steels are rated for use at 1000C Maybe Inconel? -Lasse
From: Dirk Bruere at NeoPax on 22 May 2010 09:58 On 22/05/2010 03:35, lektric.dan(a)gmail.com wrote: > On May 21, 6:34 pm, Dirk Bruere at NeoPax<dirk.bru...(a)gmail.com> > wrote: > >> Or CO2 laser? > > The problem there is temperature control. It's fairly easy to dump a > bunch of energy in - we could just as easily set of dynamite, but we > need to *control* the energy/heat. > >> Whatever is used, it is going to take a lot of power. >> What total mass will be heated to 1000 degC? > > The organic material is about 0.2 grams per cc. Carrier gas will be > either nitrogen (and remember it's di-atomic), or argon. The heating > zone is 1" long and 1/2" dia. I don't know what the flow rate of > carrier gas will be. > > I think we're getting too involved in details and not looking at what > technologies could actually give realistic results. If you are looking to heat the gaseous contents of the tube rather than the tube itself that makes quite a difference to the technologies available. The only one I can think of is a plasma induction heater. -- Dirk http://www.transcendence.me.uk/ - Transcendence UK http://www.blogtalkradio.com/onetribe - Occult Talk Show
From: Dirk Bruere at NeoPax on 22 May 2010 10:01
On 22/05/2010 10:55, Archimedes' Lever wrote: > 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://en.wikipedia.org/wiki/Glass#Composition_and_properties -- Dirk http://www.transcendence.me.uk/ - Transcendence UK http://www.blogtalkradio.com/onetribe - Occult Talk Show |