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<P style="MARGIN: 0in 0in 0pt" class=MsoNoSpacing><B
style="mso-bidi-font-weight: normal"><SPAN
style="FONT-SIZE: 18pt; mso-fareast-font-family: 'Times New Roman'; mso-bidi-font-family: Arial; mso-bidi-theme-font: minor-latin"><FONT
face=Arial><FONT size=4>I do not see how the twisted tape can create turbulence
with the low velocities in the stove. There is probably something else going on
that is increasing the efficiency. The TT may slow down the flow and reduce the
excess air?</FONT></FONT></SPAN></B></P>
<P style="MARGIN: 0in 0in 0pt" class=MsoNoSpacing><B
style="mso-bidi-font-weight: normal"><SPAN
style="FONT-SIZE: 18pt; mso-fareast-font-family: 'Times New Roman'; mso-bidi-font-family: Arial; mso-bidi-theme-font: minor-latin"><o:p><FONT
size=4 face=Arial> </FONT></o:p></SPAN></B></P>
<P style="MARGIN: 0in 0in 0pt" class=MsoNoSpacing><B
style="mso-bidi-font-weight: normal"><SPAN
style="FONT-SIZE: 18pt; mso-fareast-font-family: 'Times New Roman'; mso-bidi-font-family: Arial; mso-bidi-theme-font: minor-latin"><FONT
face=Arial><FONT size=4>You may be able to send some smoke through the stove to
see the flow path.<o:p></o:p></FONT></FONT></SPAN></B></P>
<P style="MARGIN: 0in 0in 0pt" class=MsoNoSpacing><B
style="mso-bidi-font-weight: normal"><SPAN
style="FONT-SIZE: 18pt; mso-fareast-font-family: 'Times New Roman'; mso-bidi-font-family: Arial; mso-bidi-theme-font: minor-latin"><o:p><FONT
size=4 face=Arial> </FONT></o:p></SPAN></B></P>
<P style="MARGIN: 0in 0in 0pt" class=MsoNoSpacing><B
style="mso-bidi-font-weight: normal"><SPAN
style="FONT-SIZE: 18pt; mso-fareast-font-family: 'Times New Roman'; mso-bidi-font-family: Arial; mso-bidi-theme-font: minor-latin"><FONT
face=Arial><FONT size=4>Also anything between the fire and the pot will block
radiant heat. <o:p></o:p></FONT></FONT></SPAN></B></P></DIV>
<BLOCKQUOTE
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<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US">Dear
Paul<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US">Before
rushing to put in the TT’s be aware that such devices in the actual flame will
impede combustion quite a bit, producing a lot of soot (clinging to it).
<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt; mso-fareast-language: EN-US"><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"
lang=EN-US>If the carbon falls into the fire and burns, that might be OK. If,
strictly speaking, the purpose is turbulence, it could as well be created with
secondary air jets and the soot avoided. Everyone should try it to see the
effects.</SPAN><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; FONT-SIZE: 11pt"
lang=EN-US><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"
lang=EN-US><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"
lang=EN-US><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"
lang=EN-US>Because we do not know the gas composition from the stove, it is
hard to know what the overall effect of the TTs was on combustion efficiency.
This is the sort of effect that is hard to guess.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"
lang=EN-US><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"
lang=EN-US>Regards<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"
lang=EN-US>Crispin<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"
lang=EN-US><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"
lang=EN-US><o:p> </o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"
lang=EN-US><o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 11pt"><o:p> </o:p></SPAN></P>
<DIV>
<P class=MsoNormal>Frank,<BR><BR>see below<BR><BR><o:p></o:p></P></DIV>
<BLOCKQUOTE style="MARGIN-TOP: 5pt; MARGIN-BOTTOM: 5pt">
<P class=MsoNormal><B><SPAN
style="FONT-FAMILY: 'Calibri','sans-serif'; COLOR: #1f497d; FONT-SIZE: 14pt">Surprised
to see twisted tape adding efficiency as I would think that would just
remove heat that was on its way to the pot.
</SPAN></B><o:p></o:p></P></BLOCKQUOTE>
<P class=MsoNormal>They twisted tape (TT) is quite small and will be up to
full temperature quite quickly. After that, they to not remove any
more heat. But the added turbulence continues. And
seems to have substantial impact. <BR><BR>The test of the TT could
easily be done in the Rocket stoves that have been tested so many
times. Does 1 or more TT have impact there? <BR><BR>TT is
one of several major designs for turbulence. Looks like an
important topic for more study (and does not require fancy expensive
equipment.</P></DIV></BLOCKQUOTE></BODY></HTML>