[Gasification] Electronic Ignition for Gasifiers

[Jonathan F. Pratt]

Doug,

Thank you for the comments.  I did not think it would work either to have 
anything protruding into the char zone but I would think it feasible to have 
some kind of butane pilot or "hot air gun" type system build into one or 
more of the air intake areas of the char zone.

My hope is that someone on this list may have worked out a custom solution 
using exisiting commercial controls for furnaces or has the schematics for a 
PLC type control system if not for the whole gasifier operation but at least 
for auto-ignition.

Let's assume a simple hypothetical use for a close combustion downdraft 
gasifier for heating applications.  A sensor input such as an electronic 
thermostat sends a signal  to a ignition circuit of a gasifier-heater (just 
like they do for say a forced air furnace) that it needs to be switched 
"on".  The ignition control board in sequence fires off the pilot/ignitor, 
turns the blower fan on low, and after a pre-set period of time or after a 
temp sensor (maybe even an O2 sensor) indicates conditions in the reduction 
zone are adequate then fires off a pilot and ignition sequence in the burner 
that the producer gas is directed to (just the same as the forced air 
furnaces do).

I thought a butane pilot of some kind might work out because it would 
provide fairly uniform high temp heat applied directly into the char zone, 
and not require the large amount of electrical current that say a hot air 
gun would require, and also might resemble very closely the hot air furnaces 
who's ignition sequence go very similarly, IE a pilot light is started which 
then lights the main burner (for PLC controlled furnaces that don't have 
continuous pilot flames anymore).

On the internet I found a few butane canisters, torches etc... that are used 
for soldering, as lighters and even for gormet cooking.  Basically a small 
canister of butane would be enough to last through several hundred of these 
ignition cycles for a gasifer.  The selanoids as they are used in gas 
furnaces may work just fine with butane, heck Dimethyl Ether (aerosol 
propellant)  might work good in such a system.

I know enough to build circuit boards from schematics but not to design them 
as an electrical engineer would.   I'm sure some kind of programming would 
be involved as well to program the PLC control chip/s.

Does this hit a nerve anyone?


Jonathan

----- Original Message ----- 
From: "doug.williams" <Doug.Williams at orcon.net.nz>
To: "Ian" <i.milliken at innovation-tech.co.uk>; 
<gasification at listserv.repp.org>; "Jonathan Pratt" <jonpratt76 at hotmail.com>
Sent: Wednesday, November 15, 2006 6:33 PM
Subject: Re: [Gasification] Electronic Ignition for Gasifiers


> Hi Jonathan, and Colleagues,
>
> You ask:
> > Please comment about ignition systems for gasifiers.  I presume this
> ground
>> has been covered especially for commercial gasifiers but what if any
>> automatic ignition systems might be available for smaller gasifiers for
>> heating and small power 10kw-100kw generation?
>
> You have an interesting definition of small power generation, as not too 
> many gasifiers any where visible generating in developed countries. Each 
> commercial developer will have an ignition system that suits their design, 
> and I would expect it to be probably adapted in house for the job.
>
> Whether you use hot gas, hot air, electrical elements, or glow plugs, 
> nothing can be mounted in the actual char that is normally the oxidation 
> zone, because this is the char that the heating has to ignite. You are not 
> just heating the reduction char, you are supplying heat containing oxygen, 
> that will then allow the char to ignite in the oxidation zone
>
> If you have the expertise, anything is possible if you do it yourself. But 
> if you want a custom built system, then I can only refer you to our 
> licensee ITI in N.Ireland, www.innovation-tech.co.uk  as they actually 
> know what you need, and manufacture control systems for all sorts of 
> specialized applications.
>
> While the fully automated gasifier is possible, the cost of the components 
> will determine it's practicallity. Add an engine, and it becomes a lot 
> more expensive, but time will reduce costs, as modular components might 
> adapt simply from other technologies.
>
> Hope this helps.
> Doug Williams,
> Fluidyne Gasification.
>
>
>
>
>
>