tag:blogger.com,1999:blog-6911752388384243976.post2347074396625361302..comments2023-04-05T13:37:33.168+01:00Comments on IEC Fusion Technology: Vacuum PumpingM. Simonhttp://www.blogger.com/profile/09508934110558197375noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-6911752388384243976.post-45379088403474982642007-12-23T00:26:00.000+00:002007-12-23T00:26:00.000+00:00A vacuum system is critical to correct testing and...A vacuum system is critical to correct testing and strong vacuum was designed into the test chamber to allow evacuation in instability times. A poor reaction plasma was to be evacuated into safe configuration.<BR/><BR/>High volume pumps are required and explosive blast plates would make for the correct test chamber design. A plate blasted to open the chamber evacuation area.<BR/><BR/>Safe configuation then ensues.<BR/><BR/>I can only hope the meaning of neutron structure is unstood.Douglas Eaglesonhttps://www.blogger.com/profile/03967032372050649269noreply@blogger.comtag:blogger.com,1999:blog-6911752388384243976.post-75613495581496402342007-11-27T02:28:00.000+00:002007-11-27T02:28:00.000+00:00Did you get the Microsoft Word file about Knudsen ...Did you get the Microsoft Word file about Knudsen Diffusion? If so, how would you rate it? Would you say was easy to understand, had unnecessary detail or information, was overly redundant, was too elementary, was unclear….<BR/>You can also e-mail me at ZetaAntares at aol dot com.brenthttps://www.blogger.com/profile/13618115068901706413noreply@blogger.comtag:blogger.com,1999:blog-6911752388384243976.post-65943851054733442452007-11-22T18:17:00.000+00:002007-11-22T18:17:00.000+00:00Brent,Here is a look at Turbo Molecular Pumps.Also...Brent,<BR/><BR/>Here is a look at <A HREF="http://en.wikipedia.org/wiki/Turbomolecular_pump" REL="nofollow">Turbo Molecular Pumps</A>.<BR/><BR/>Also have a look at <A HREF="http://iecfusiontech.blogspot.com/2007/11/vacuum-pumping.html" REL="nofollow">Vacuum Pumping</A>.<BR/><BR/>And <A HREF="http://iecfusiontech.blogspot.com/2007/11/turbo-pump-ratings.html" REL="nofollow">Turbo Pump Ratings</A>M. Simonhttps://www.blogger.com/profile/09508934110558197375noreply@blogger.comtag:blogger.com,1999:blog-6911752388384243976.post-83859687191292326752007-11-22T16:13:00.000+00:002007-11-22T16:13:00.000+00:00It looks like you have a firm understanding of the...It looks like you have a firm understanding of the problems at hand. Much better than I do. <BR/>You probably know this as well, but I'll just throw it out:<BR/><A HREF="http://www.engineeringtoolbox.com/pumps-parallel-serial-d_636.html" REL="nofollow">Pumps in Series vs. Pumps in Parallel on Engineering Toolbox</A><BR/><BR/>Thanks for filling me in on what a turbo pump is. I wasn't really sure. For further clarification, are they like special<BR/>centrifugal pumps as this <A HREF="http://turbolab.tamu.edu/pubs/Pump22/P22pg016.pdf" REL="nofollow"><BR/>article</A> suggests?brenthttps://www.blogger.com/profile/13618115068901706413noreply@blogger.comtag:blogger.com,1999:blog-6911752388384243976.post-2791061913892080422007-11-22T06:38:00.000+00:002007-11-22T06:38:00.000+00:00Brent,I'm familiar with the pump issues you mentio...Brent,<BR/><BR/>I'm familiar with the pump issues you mention including cavitation. <BR/><BR/>Turbo molecular pumps are different. Once in their operating range the flow (for a particular gas) is constant despite declining pressure. <BR/><BR/>I'm also familiar with the hydrogen embrittlement problem. <BR/><BR/>Low pressures cause an outgasing of the hydrogen. So does the cookout prior to operation. It will warrant attention. I do not think it is a serious problem. <BR/><BR/>BTW the only above atmospheric source of hydrogen is the storage tanks and the initial regulators. The majority of the plumbing and tanks are well below atmospheric. <BR/><BR/>The only other concern is H2 exhausted from the reactor. It will be less than .1 cc/ second (for the test reactor) and could be safely vented to the lab. An outdoor vent is the wise thing to do though. It will be important to keep the vent pipe short and flooded with an inert gas (N2 or Argon) to avoid explosion problems.M. Simonhttps://www.blogger.com/profile/09508934110558197375noreply@blogger.comtag:blogger.com,1999:blog-6911752388384243976.post-53613071360985039742007-11-22T05:13:00.000+00:002007-11-22T05:13:00.000+00:00Frogive me, the G12/07-N pump produces very small ...Frogive me, the G12/07-N pump produces very small flows. It is therefore not useful for excavating large chambers. I know, it could have sounded like that.brenthttps://www.blogger.com/profile/13618115068901706413noreply@blogger.comtag:blogger.com,1999:blog-6911752388384243976.post-24547512471843133812007-11-22T05:03:00.000+00:002007-11-22T05:03:00.000+00:00Comments about Pumps:I looked at the turbo Pump de...Comments about Pumps:<BR/><BR/>I looked at the turbo Pump description for the Pfieffer HiMag 3400 vacuum pump. It’s been awhile since I learned about sizing a pump, but I seem to remember that we used to look at pump performance curves consisting of NPSH (Net Positive Suction Head) vs. Flow Rate to get an idea of how a pump behaves. In addition, I believe positive displacement pumps are used for low flow rates as well as for gritty material (e.g. augers), and centrifugal pumps are used for higher flow rates. Sometimes you have to worry about cavitation with centrifugal pumps, which is damage to the pump blades caused by expanding vapor bubbles. Obviously my memory is a little fuzzy at this point.<BR/>The <A HREF="http://www.pumpworld.com/centrif5.htm" REL="nofollow">Pump World</A> website has something to say about this.<BR/><BR/>From what I’ve seen about the <A HREF="http://onlinecatalog.pfeiffer-vacuum.net/en/4419/showDetail.do;jsessionid=9F0AAE138305480309988D556302122E" REL="nofollow">Pfieffer HiMag 3400</A> vacuum pump, it seems reasonable. The purpose is to evacuate air I presume. It’s also rated for hydrogen, which is nice. <BR/>I’ll need to look into more closely. You might want to check out the link that says Characteristic. It looks like a flow rate vs. pressure graph (I would guess this is the output flow and output pressure).<BR/><BR/>Another place to look for pumps is the <A HREF="http://www.thomaspumps.com/pdf/ThomasStandardProductsCatalog.pdf" REL="nofollow">Thomas Standard Products Catalog</A>. I’ve investigated the G12/07-N pump the most closely. Larger pumps are also available here. Further details are in the e-mail I’ve sent you. <BR/><BR/>I’ve also found some additional links about pumps. It appears that if the pump performance curves are not available you can <A HREF="http://www.chemicalprocessing.com/articles/2006/008.html" REL="nofollow">estimate the performance</A> using the pump affinity laws. <A HREF="http://www.engineeringtoolbox.com/affinity-laws-d_408.html" REL="nofollow">Engineering Toolbox</A> provides a good way of estimating this. <BR/><BR/>I also found an <A HREF="http://www.physik.uni-stuttgart.de/studium/praktika/ap/pdf_dateien/S25.pdf" REL="nofollow">article</A> from Germany that describes complications for Vacuum pumps. Much to my Chagrin, it’s in German. If you want to look at it you might try <A HREF="http://babelfish.altavista.com" REL="nofollow">Babel Fish</A> or <A HREF="http://www.google.com/language_tools" REL="nofollow"> Google Language Tools </A>.<BR/><BR/>A word about hydrogen: it is commonly thought of as a bear in industry. It causes <A HREF="http://en.wikipedia.org/wiki/Hydrogen_embrittlement" REL="nofollow"> embrittlement </A> in many steels primarily by migrating into imperfections in the material and forming high pressure methane bubbles. Or at least that is my understanding from what I have seen on the Internet thus far. Hydrogen also manages to find any holes; so hermetic sealing is sometimes a good idea. For a manufacturer try going to <A HREF="http://www.hccindustries.com" REL="nofollow">hcccindustries.com --industries served--automotive</A>. Also see two additional articles, one from <A HREF="http://en.wikipedia.org/wiki/Hydrogen_piping'" REL="nofollow">Wikipedia</A> and another from the <A HREF="http://www.leightyfoundation.org/files/IPC06-Calgary/IPC06-25Sep06-Calgary-Program.pdf" REL="nofollow"> International Pipeline Conference </A>.<BR/><BR/>I’ll have to take a look at my old Plant Economics Textbook. Hopefully what I’ve said so far is helpful.brenthttps://www.blogger.com/profile/13618115068901706413noreply@blogger.com