Dear Paul ----- Original Message ----- From: Paul Olivier To: Discussion of biomass cooking stoves Sent: Tuesday, March 06, 2012 1:00 AM Subject: Re: [Stoves] the 150 gasifier in operation in Vietnam
Kevin, I do not think that normal mild steel wire mesh would make it through a single gasifier run. # Certainly, "red hot mild steel" in an oxidizing air atmosphere will scale up and fail quickly. However, you don't have that.... you have a combustion zone atmosphere. It is very simple and cheap[ to try. Try it, and let the screen itself tell you that it needs to be of higher quality. I'm afraid that it has to be something "exotic". # Let the system prove to you that it needs to be exotic. :-) This wire mesh really gets hot. # "Hot" is one thing, but "oxdizing atmosphere" is another. If the atmosphere the screen "sees" is "adequately reducing", then mild steel might be an economically good solution. On the other hand, as the atmosphere becomes increasingly oxidizing, then the more exotic materials are required. Someone measured the temperature about 4 inches above the dome. When the probe reached 500 C, he stopped. # A material that would fail in air at 500 C might be quite acceptable in a reducing atmosphere at 500 C # The problem is one of Temperature AND Atmosphere. You could probably reduce costs safely, with a test program that confirmed the minimum quality screen material that would do an acceptable job. Best wishes, Kevin Thanks. Paul On Tue, Mar 6, 2012 at 11:39 AM, Kevin <[email protected]> wrote: Dear Paul Why not start with simple mild steel screen, of various sizes, and test them to see how long they last? Exotic materials will probably last longer, but at a very much higher cost. Once you have cost and "lifetime" information, then you can make the best decision about what materials to use. Best wishes, Kevin ----- Original Message ----- From: Paul Olivier To: Discussion of biomass cooking stoves Sent: Tuesday, March 06, 2012 12:12 AM Subject: Re: [Stoves] the 150 gasifier in operation in Vietnam 446 stainless can handle temperatures as high as 1,200 C. Silicon carbide is quite cheap, and it can handle temperatures as high as 1,650 C. http://accuratus.com/silicar.html Thanks. Paul On Tue, Mar 6, 2012 at 11:02 AM, Anand Karve <[email protected]> wrote: Dear Paul, I have not worked with that grade of stainless steel and also not worked with silicon carbide mesh. Yours A.D.Karve On Tue, Mar 6, 2012 at 11:58 AM, Paul Olivier <[email protected]> wrote: A.D., I am looking for a 446 stainless steel wire mesh. Have you ever worked with silicon carbide mesh? It is used as an emitter in thermophotovoltaics. Paul On Tue, Mar 6, 2012 at 10:54 AM, Anand Karve <[email protected]> wrote: Dear Paul, even stainless steel is no good. At high temperature, it corrodes and crumbles into pieces. Yours A.D.Karve On Mon, Mar 5, 2012 at 4:03 PM, Steve Taylor <[email protected]> wrote: On 5 March 2012 02:56, Paul Olivier <[email protected]> wrote: I know that a tungsten wire mesh exists. But no doubt this would be too expensive. Tungsten will oxidise to nothing very quickly. Probably Incoloy would be ideal Steve _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org for more Biomass Cooking Stoves, News and Information see our web site: http://www.bioenergylists.org/ -- *** Dr. A.D. Karve Trustee & Founder President, Appropriate Rural Technology Institute (ARTI) _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org for more Biomass Cooking Stoves, News and Information see our web site: http://www.bioenergylists.org/ -- Paul A. Olivier PhD 27C Pham Hong Thai Street Dalat Vietnam Louisiana telephone: 1-337-447-4124 (rings Vietnam) Mobile: 090-694-1573 (in Vietnam) Skype address: Xpolivier http://www.esrla.com/ _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org for more Biomass Cooking Stoves, News and Information see our web site: http://www.bioenergylists.org/ -- *** Dr. A.D. Karve Trustee & Founder President, Appropriate Rural Technology Institute (ARTI) _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org for more Biomass Cooking Stoves, News and Information see our web site: http://www.bioenergylists.org/ -- Paul A. Olivier PhD 27C Pham Hong Thai Street Dalat Vietnam Louisiana telephone: 1-337-447-4124 (rings Vietnam) Mobile: 090-694-1573 (in Vietnam) Skype address: Xpolivier http://www.esrla.com/ -------------------------------------------------------------------------- _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org for more Biomass Cooking Stoves, News and Information see our web site: http://www.bioenergylists.org/ -------------------------------------------------------------------------- No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2114/4852 - Release Date: 03/05/12 _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org for more Biomass Cooking Stoves, News and Information see our web site: http://www.bioenergylists.org/ -- Paul A. Olivier PhD 27C Pham Hong Thai Street Dalat Vietnam Louisiana telephone: 1-337-447-4124 (rings Vietnam) Mobile: 090-694-1573 (in Vietnam) Skype address: Xpolivier http://www.esrla.com/ ------------------------------------------------------------------------------ _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org for more Biomass Cooking Stoves, News and Information see our web site: http://www.bioenergylists.org/ ------------------------------------------------------------------------------ No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2114/4852 - Release Date: 03/05/12
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