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<DIV>Dr Karve and listers, Hello,</DIV>
<DIV> </DIV>
<DIV>Tests I tried in a laboratory which involved pumping material into a digester suggested that flow velocity is important. The microbes do not seem to like being accelerated, and stop working. A centrifugal pump works by accelerating the fluid, so is not really suitable for use in an anaerobic digester. The type of pump most often used is a progressive cavity pump, although an archimedes screw is also good. </DIV>
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<DIV>Unfortunately, the project was not properly written up, mainly because it did not produce biogas. I did try to write a patent on the idea, but as it did not work, it became rather pointless. </DIV>
<DIV> </DIV>
<DIV>Best wishes,</DIV>
<DIV>David</DIV>
<DIV><A href="mailto:davidf@kingdombio.com"><EM><FONT size=2>davidf@kingdombio.com</FONT></EM></A></DIV>
<DIV> </DIV>
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<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: Tahoma"><FONT size=2 face=Verdana><FONT color=#604c78>******************************************************<BR>Dr David Fulford CEnv MEI, 15, Brandon Ave, Woodley, Reading RG5 4PU<BR> Tel: +44(0)118 969 5039 Mob: +44(0)7746 806401<BR>Kingdom Bioenergy Ltd, </FONT><A href="www.kingdombio.com" target=_BLANK><EM><FONT color=#604c78>www.kingdombio.com</FONT></EM></A><FONT color=#604c78>, </FONT><A href="mailto:davidf@kindombio.com" target=_BLANK><EM><FONT color=#604c78>davidf@kindombio.com</FONT></EM></A><BR><FONT color=#604c78> Skype Identity: djfulford</FONT></FONT></DIV></DIV>
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<DIV> </DIV>
<DIV> </DIV>
<DIV>------ Original Message ------</DIV>
<DIV>From: "Anand Karve" <<A href="mailto:adkarve@gmail.com">adkarve@gmail.com</A>></DIV>
<DIV>To: "For Discussion of Anaerobic Digestion" <<A href="mailto:digestion@lists.bioenergylists.org">digestion@lists.bioenergylists.org</A>></DIV>
<DIV>Sent: 16/11/2013 07:35:15</DIV>
<DIV>Subject: Re: [Digestion] Use of centrifugal pump for transferring feedstock into digester</DIV>
<BLOCKQUOTE class=cite cite=CACPy7ScxnFW0Bqt9Vp10JF8mB=Zos=fnxznw54RWOVg1tcANcA@mail.gmail.com type="cite">
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<DIV dir=ltr>Dear Marc,
<DIV>the feedstock is going into the digester all right. So obstruction in the feed line is not the problem. </DIV>
<DIV>Yours</DIV>
<DIV>A.D.Karve</DIV></DIV>
<DIV class=gmail_extra><BR><BR>
<DIV class=gmail_quote>On Sat, Nov 16, 2013 at 8:04 AM, Marc de Piolenc <SPAN dir=ltr><<A href="mailto:piolenc@archivale.com">piolenc@archivale.com</A>></SPAN> wrote:<BR>
<BLOCKQUOTE class=gmail_quote style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">There are at least two other possibilities<BR><BR>- cavitation within the pump leading to loss of "prime"; this is heavily dependent on where the pump is installed, bends and constriction in the feed line and so on<BR><BR>- formation of gas bubbles in the feed; why wouldn't fermentation start in the feed, given the right conditions? Those gas bubbles will act just like water vapor (cavitation) or air intrusion, and make the pump lose its "prime."<BR><BR>The usual remedy is installing a manual, reciprocating pump in line with the centrifugal pump. This is used for initially priming the centrifugal pump and for re-priming it if it gets gas-locked or "sucks dry." Whether this will work with a relatively thick slurry or not, I don't know.<BR><BR>Marc de Piolenc<BR>-- <BR>Archivale catalog: <A href="http://www.archivale.com/catalog">http://www.archivale.com/<U></U>catalog</A><BR>Polymath weblog: <A href="http://www.archivale.com/weblog">http://www.archivale.com/<U></U>weblog</A><BR>Translations (ProZ profile): <A href="http://www.proz.com/profile/639380">http://www.proz.com/profile/<U></U>639380</A><BR>Translations (BeWords profile): <A href="http://www.bewords.com/Marc-dePiolenc">http://www.bewords.com/Marc-<U></U>dePiolenc</A><BR>Ducted fans: <A href="http://massflow.archivale.com/">http://massflow.archivale.com/</A><BR><BR>______________________________<U></U>_________________<BR>Digestion mailing list<BR><BR>to Send a Message to the list, use the email address<BR><A href="mailto:Digestion@bioenergylists.org">Digestion@bioenergylists.org</A><BR><BR>to UNSUBSCRIBE or Change your List Settings use the web page<BR><A href="http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org">http://lists.bioenergylists.<U></U>org/mailman/listinfo/<U></U>digestion_lists.<U></U>bioenergylists.org</A><BR><BR>for more information about digestion, see<BR>Beginner's Guide to Biogas<BR><A href="http://www.adelaide.edu.au/biogas/">http://www.adelaide.edu.au/<U></U>biogas/</A><BR>and the Biogas Wiki <A href="http://biogas.wikispaces.com/">http://biogas.wikispaces.com/</A><BR><BR></BLOCKQUOTE></DIV><BR><BR clear=all>
<DIV><BR></DIV>-- <BR>***<BR>Dr. A.D. Karve<BR>Trustee & Founder President, Appropriate Rural Technology Institute (ARTI)<BR><BR></DIV></DIV></BLOCKQUOTE></BODY></HTML>