Fwd: [Gasification] We use to dream of making one of these

[jim mason]

diy mixture sensor details from peef.

j


---------- Forwarded message ----------
From: ¤ pEEf ¤ <pEEf at mindfart.com>
Date: May 19, 2006 12:42 AM
Subject: Re: [Gasification] We use to dream of making one of these
To: jim mason <jimmason at whatiamupto.com>

 It's super-easy to make a mixture meter.  All you need is a digital volt
meter and a $30 oxygen sensor from the auto parts store.  If you want to use
it at the exhaust exit, get the 3-wire kind (heated). (also more responsive)
 The 2 black wires go across 12v (heater) and the white wire and the case
across the DVM.

voltage less than .05 = Bad Sensor
.05v to .3v = Lean
.4 to .6 = Stoichiometric Mixture Realm
.7 to 1v = Rich

The Oxygen sensor voltage should stand true for any fuel.
The ideal Stoich mixtures differ though:

Gasoline: 1:14:7
Propane: 1:15.6
Diesel: 1:14.5
Hydrogen: 1:27.2

Generally you target .5v.  Most Fuel injection systems start decreasing the
injector pulse width at .45v and increasing at .55v

I've done it, works great!

Remember, a perfect Stoichiometric mixture, with perfect combustion, would
result in no oxygen reaming in the exhaust.  This indicates perfect
oxidation of the fuel mixture, which is the goal.

Given that an internal combustion engine is not an ideal environment for
totally pure and complete oxidation of the fuel mix, there is always a
little oxygen left over anyway.   But monitoring of this will give you a
clue of how good a job you are doing.  The Oxygen sensor has some kind of
rare elements in it that cause it to act like a little tiny oxygen sensor
and generate a voltage in response to the Oxygen remaining.

In theory, this technique could be used in situations where you are trying
to burn fuel with perfect result.  The only problem would be if your
measurement technique (Oxygen Sensor) is damaged by the other components in
the exhaust.  My take on this is that Diesels would be a good example of a
system that you should use an O2 sensor on.  I would guess that the
combustion products would clog up an oxygen sensor rather fast, but I'm not
positive.

A quick walk over to the WikiPedia gives a wealth of information as usual:
http://en.wikipedia.org/wiki/Oxygen_sensor

Way more than I knew, in fact!

Peef







---------- Forwarded message ----------
From: Peter Singfield <snkm at btl.net >
Date: May 18, 2006 10:55 PM
Subject: [Gasification] We use to dream of making one of these
To: gasification at listserv.repp.org


Now you can take it right off the shelf.

http://www.woodward.com/pdf/ic/03553.pdf

Total controller for your gasifier.

Peter / Belize
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