On Sun, Oct 3, 2010 at 3:33 AM, jim mason <[email protected]> wrote: > the rotor made from the spinning disk with vanes between we have not > yet tested. we should i agree.
that was to say *two* spinning disks, with the vanes between. > we have testing the one sided version > with vanes at various angles forward and back from perpendicular. i > was surprised to find it makes little difference. backward rake, > espeically curve backwards at the tip is done with pro fans to reduce > noise, not increase pressure/vac. it actually reduces performance a > bit. > > it has taken awhile to get through my head that these fans are working > as centrifugal devices, not pressure devices. the blades are not > levers or pumps. they are simple accelerators for air mass. your > pressure/vac is coming from velocity and inertia/momentum. > > this is why the tightness to the walls makes little difference. i've > moved the rotor / wall tolerance around quite a bit and saw very > little diffference. i've read this is also why you see less double > walled rotors that one might expect. but i've yet to test this so > can't really say. greg says he gets 25% more out of these types. > > some devices in the weed blower vac world put vanes on both sides of > teh disk. but i think this is to prevent the weeds from getting stuck > on the back of the disk. see the toro blower for example of this. > > arnt raises an interesting concern about the rotor bending. the other > way to deal with this would be to make a full slot for the vanes, and > push the vanes through so they stick out on both sides. put a hole in > the center so air can feed to both sides of the rotor. > > and . . . i have to suggest it. . . > > this might finally be a reasonable application for a tesla turbine. > many parallel disks, no vanes or welding. problem is the distance > between the disks needs to be related to the laminar layer thickness > at the rpms one is running. the distances are usually very small. > like a few 100ths of an inch. these are difficult tolerances to > maintain with junk cut metal. > > however, it begs to be tried. we will soon here. maybe at the > workshop next weekend. > > j > > > > > > On Sat, Oct 2, 2010 at 7:39 PM, Greg Manning <[email protected]> wrote: >> >> >> Greetings Jim, and list members. >> >> Jim, if you want a better fan, (and cheaper), simply make 2 disks (one >> mounts on the shaft, the other has the larger hole for the inlet.) >> >> then use strips of heavy tin (or light gauge metal) and form them into a Z >> shape (well, an L with a dog leg the other end, and the opposite way, >> somewhat like a "90 degree Z") >> >> take these and pop rivet with STEEL rivets (NOT aluminum ones) so they are >> sandwiched between the two disks in a radial fashion (like your welded >> version on your site, BUT with the extra disk on the inlet side of things. >> >> the extra disk should run as close as it can to the outer housing the >> Bernoulli principal will help stabilize the outer disk, and the outer disk >> will add about 25% more suction to the unit for the same RPM (therefore the >> entire unit could be built smaller and lighter). >> >> Greg Manning, >> Canadian Gasifier Ltd. >> Building Hi-Performance Gasifiers, Since 2001 >> >> Brandon, Manitoba, Canada >> 1 (204) 726-1851 >> >> >> >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]]on Behalf Of jim >> mason >> Sent: Saturday, October 02, 2010 4:58 PM >> To: [email protected] >> Subject: [Gasification] tests to design a new cheap gasifier fan >> >> >> we've been doing some work lately to design a new fan/blower that will >> produce the needed vac and heat tolerance for gasifier operation. as >> we all know, there is not an inexpensive source for such a thing from >> other industries and applications. thus we had to build one for the >> early gek kits. >> >> the original gek fan proved to not be strong enough once we finally >> characterized the vac numbers that produce the flow/heat rates that >> correspond to full tar conversion. the ejector/venturi solution we're >> using currently produces plenty of vac and is very flexible, but >> requires compressed air. this is not good for many off grid >> situations. thus we still need a good fan/blower source. and one >> that works on 12vdc, not an ac source. >> >> here's the info an pictures of our recent tests to produce this. we >> are working towards a much simplified solution that also gets rid of >> the welding to make it. this is based on the common car/truck fasco >> type fan motor. >> >> http://gekgasifier.com/forums/showthread.php?t=455 >> >> jim >> >> >> >> -- >> ---------------------------------------------------------------------------- >> -- >> Jim Mason >> Website: http://www.whatiamupto.com >> Current Projects: >> - Gasifier Experimenters Kit (the GEK): http://www.gekgasifier.com >> - Escape from Berkeley alt fuels vehicle race: www.escapefromberkeley.com >> - ALL Power Labs on Twitter: http://twitter.com/allpowerlabs >> - Shipyard Announce list: >> http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com >> >> _______________________________________________ >> Gasification mailing list >> [email protected] >> http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenerg >> ylists.org >> No virus found in this incoming message. >> Checked by AVG - www.avg.com >> Version: 9.0.856 / Virus Database: 271.1.1/3158 - Release Date: 10/02/10 >> 01:34:00 >> >> >> _______________________________________________ >> Gasification mailing list >> [email protected] >> http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org >> > > > > -- > ------------------------------------------------------------------------------ > Jim Mason > Website: http://www.whatiamupto.com > Current Projects: > - Gasifier Experimenters Kit (the GEK): http://www.gekgasifier.com > - Escape from Berkeley alt fuels vehicle race: www.escapefromberkeley.com > - ALL Power Labs on Twitter: http://twitter.com/allpowerlabs > - Shipyard Announce list: > http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com > -- ------------------------------------------------------------------------------ Jim Mason Website: http://www.whatiamupto.com Current Projects: - Gasifier Experimenters Kit (the GEK): http://www.gekgasifier.com - Escape from Berkeley alt fuels vehicle race: www.escapefromberkeley.com - ALL Power Labs on Twitter: http://twitter.com/allpowerlabs - Shipyard Announce list: http://lists.spaceship.com/listinfo.cgi/icp-spaceship.com _______________________________________________ Gasification mailing list [email protected] http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org
