[Gasification] Gasifiers and kilns

[Arnt Karlsen]

On Wed, 15 Nov 2006 16:53:01 -0000, Paul wrote in message 
<MCBBKFBMAJDKKHEEMOCOGEKECGAA.pstubbs at uwclub.net>:

> As a potter and kiln builder im intrigued by the idea of using a
> gasifier to generate gas to fire pottery kilns. What would be required
> would be a variable output with a maximum delivery of 15,000 Bthu per
> cu foot of chamber size.

..15kBtu/cuft, (or 559MJ/m^3) that's common for a 12hour glaze fire?

> The whole cycle might run over a period of 8 to 12 hours I would be
> initially interested in trying it out on a test kiln of about 5 cu ft.

..79MJ or 22kWh, needs just 1.8 to 2.7kW of heat.  Can do.  ;o)
For production, say 13kW to 19kW per cubic meter.

> Is this a do-able project or is a gasifier not  suitable for a wide,
> variable-output situation.

..piece of cake, really belongs in the WTF-are-you-waiting-for.  ;o)

>  I would envisage using chipped hard wood (oak), a forced air fan for
> secondary air at the burner and presumably a variable blower at the
> front end to provide the draught to the ember bed.

..if you cool your gas, you can use a fan downstream of the cooler,
avoids pressurising your gasifier, if there are leaks, you'll prefer air
leaks going in to create hot spot in your piping, rather than sneaky
poisonous CO gas leaking out to kill you.

..for control, you need timed temperature profiles and you will wanna
do air/gas mixture control profile combinations, so you'll want a car
tail pipe kinda O2 sensor too in your kiln stack.

..and if grid power is lost, you don't wanna have your kiln fans die, so
spend a wee bit of gas in an hot standby genset and sell whatever you
feed back to the grid people.  ;o)

> I guess no worries about tar with this type of application

..tar vapors a problem?  Hmmm, you might even _want_ tar in both 
your biscuit and glaze firings, the 3 potters I know are weird people,
artists, and of course with _no_ money.  ;o)

>  I would welcome any comments and suggested reading on this.
>  Paul Stubbs Ceramics,Kilns and Potters Tools.pstubbs at uwclub.net

-- 
..med vennlig hilsen = with Kind Regards from Arnt... ;o)
...with a number of polar bear hunters in his ancestry...
  Scenarios always come in sets of three: 
  best case, worst case, and just in case.