[Gasification] tests to design a new cheap gasifier fan
jim mason
jim at allpowerlabs.org
Sun Oct 3 05:37:09 CDT 2010
On Sun, Oct 3, 2010 at 3:33 AM, jim mason <jim at allpowerlabs.org> 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 <a31ford at gmail.com> 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: gasification-bounces at lists.bioenergylists.org
>> [mailto:gasification-bounces at lists.bioenergylists.org]On Behalf Of jim
>> mason
>> Sent: Saturday, October 02, 2010 4:58 PM
>> To: gasification at bioenergylists.org
>> 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
>>
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>
>
>
> --
> ------------------------------------------------------------------------------
> 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
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