<br><br><div class="gmail_quote">On 17 July 2012 14:36, David G. LeVine <span dir="ltr"><<a href="mailto:dlevine@speakeasy.net" target="_blank">dlevine@speakeasy.net</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"><div class="im"><br></div>
Is there a good reason that a TLUD can not be hexagonal or
octagonal? Hexagonal packs better, but either can be made to fold
almost flat (assuming normal hinging.) Having multiple staggered
hinges allows very close to flat with only a small amount of
non-flat overhang.<br><br></div></blockquote><div><br>Aren't they round to ensure uniform gas flow conditions for both primary AND secondary air ? <br> </div></div>