[Terrapreta] Terrapreta Digest, Vol 11, Issue 71, message 8Greg!

[Nikolaus Foidl]

Dear Greg!

You are exactly right. Its a cylinder with a pressure bottom and a submarine
like pressure lid with a quick opening and closing device, a sealing which
will work in a temperature range of up to 700 degrees Celsius and a feeding
tube for compressed air and cooling steam and a pressure release valve which
keeps pressure at a preset value. Additional you need a security pressure
release valve which is set some bars higher then your working pressure and
then you are set to work.Make sure that your pressure kiln can withstand at
least 2,5 times the working pressure under a 1,5 time higher temperature
then your working temperature so things dont go out of hand. My kiln works
at 35 bars and 400 to 450 degrees Celsius and has a 2 " wall thickness made
of an special heat resistant steel. Its not for backyard operation, its kind
of expensive for small volumes. I will produce some 20 tons of Charcoal a
day with this Kiln.


Best regards Nikolaus
> 
> Message: 8
> Date: Fri, 28 Dec 2007 08:57:39 -0700
> From: "Greg and April" <gregandapril at earthlink.net>
> Subject: Re: [Terrapreta] Terrapreta Digest, Vol 11, Issue 70
> To: "Terra Preta" <terrapreta at bioenergylists.org>
> Message-ID: <004901c8496a$5fb94ec0$2101a8c0 at GREG>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=original
> 
> Ok, how does one make a high pressure kiln - I keep having this vision of a
> metal box with a presser relief valve that opens once it reaches a certain
> pre set pressure.
> 
> Greg H.
> 
> ----- Original Message -----
> From: "Nikolaus Foidl" <nfoidl at desa.com.bo>
> To: <terrapreta at bioenergylists.org>
> Sent: Thursday, December 27, 2007 14:10
> Subject: Re: [Terrapreta] Terrapreta Digest, Vol 11, Issue 70
> 
> 
>> Dear Gerhard!
>> 
>> I only heat the Wood up to 280 degrees Celsius .In my atmospheric kiln
>> this
>> takes some 3 hours. ( Gas outlet temperature from the gas tube). I still
>> don't know how many time it will take on my new high pressure kiln. The
>> torrefied wood is very brittle as most of the hemi cellulose is already
>> gone
>> and the cellulose is partially charred.
> 
> 
> 
> 
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