[Gasification] Sealing for gasifier?

Sun Sep 11 15:44:07 CDT 2011

repost from woodgas list on other sealing options.  i thought it might
be interesting for some here too.

-------------------------------------------------------

here's the list of what we found and like so far at apl for sealing
solutions.  if others
know of other interesting options, i'd love to hear them. getting
reasonable seals
in the various places continues to be a challenge.

for everything 300c and below we use silicone sheet of 3/32" thickness and 40
durometer. we cut it to the flange shape on a cnc laser. this is silly, we
should really be pouring them. pouring silicone is not difficult. but we're
not yet set up to do this. in the interim, we cut sheet. sheet is easy to get.

however one gets the silicone gasket, you can rtv it in place. use the orange
rtv from the autoparts store. if you are really worried about seal, put it on
the other side too. the result seals perfectly as long as your flanges are
reasonably aligned.

for things over 300c we use ceramic braided tape, with sticky on one side and
fireplace black mortar on the other side. we use this to put together hearth,
reactor, cyclone etc hot joints.

mcmaster sells this tape by the roll. see here:
http://www.mcmaster.com/#4057k3/=dt4nkx

when we install the flange we cover the ceramic tape with the black mortar. the
mortar hardens, so if you need to redo the join, you need to put on more mortar.
the tape however we do a couple cycles.

on the filter we're starting to use edge grip seal. this is a split gasket you
push over an exposed edge, letting you do a pressure cap onto it. the list of
options in mcmaster is here:
http://www.mcmaster.com/#catalog/117/3439/=dt4n5t the specific one we use on
the power pallet filter is #: 12335A54

there are also all silicone edge bulb gaskets like this, though the clean slot
one we've used before isn't showing up anymore in the list.
http://www.mcmaster.com/#silicone-rubber-bulb-seal-gaskets/=dt4pwe

our "get out of jail" hack gasket of choice is clay cord weatherstripping. as
it is clay, it will deal with very high temps. we've often used it to bolt in
hearths. it is easy to form and fill nearly anything. somewhat messy to clean
on the next install though. it is only one use.
http://www.mcmaster.com/#catalog/117/3393/=dt4qlu

there is also a purpose made "clay rope" like this used in the boiler world.
i've yet to try it, but should. it is extruded into a rope shape, but no rope
in the center. see here:

http://www.deaconindustries.com/high-temperature-sealant.html
http://www.pres-seal.com/

hoppers we now do with silicone sheet, but used to use many standard weather
stripping products. either will work fine.

to the degree you are really worried, get a tube of standard house silicon caulk
from the hardware store. the 100% stuff will take up to 300c, and it is 5
dollars a tube. put it on any joint surface you are worried about leaking.

leaks are easy to have, and they can do surprising damage. most of us don't pay
much attention to them in the early stages, as we figure we are running vac, and
need to get air in anyways. or at least i did. in reality air leaks at the
wrong places and amounts can completely change the performance of the hearth
and/or burn up most of your gas before you have a chance to use it.

the best starting place is zero leaks. then if interesting start controlling
the leaks of air back in the hopper at higher loads to extend the reactors
range, and/or to convince yourself you just secretly solved the tar cracking
problem!

j

On Sun, Sep 11, 2011 at 1:34 PM, jim mason <jim at allpowerlabs.org> wrote:
> On Sun, Sep 4, 2011 at 8:49 PM, Pete & Sheri <spaco at baldwin-telecom.net> wrote:
>>
>>   A “Quad ring” is a sort-of  square cross section ring, with o-shaped
>> edges.
>>
>> See:
>>
>> http://www.daemar.com/pdfs/118-DMR_Quad-Ring-GrooveDesign_01.pdf
>>
>> for a better look at one style.  There are others.
>>
>>
>
>
> i had not seen that one.  thank you pete.  it looks like this might
> stay in a groove or around an edge better than a straight O-ring.
>
> i also just found. turns out you can buy the fiberglass/ceramic rope
> premade with a silicone cover. this sounds useful, for combination of
> flexibility and seal.  however, still only 300c tops in constant use.
>
> silicon sealed rope
> http://www.davlyn.com/products/product.php?id=6
> http://www.adlinsulflex.com/high-temp-rope?gclid=CN7O54yB76oCFRA5gwodcgF4NQ
>
> j
>
>
>
>
>>
>> Pete Stanaitis
>>
>> -----------------
>>
>> _______________________________________________
>> Gasification mailing list
>>
>> to Send a Message to the list, use the email address
>> Gasification at bioenergylists.org
>>
>> to UNSUBSCRIBE or Change your List Settings use the web page
>> http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org
>>
>> for more Gasifiers,  News and Information see our web site:
>> http://gasifiers.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