GEK Wiki / Light-Up and Run Instructions
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Light-Up and Run Instructions

Page history last edited by jay 10 years, 2 months ago

Go back to First-Run Start-Up Instructions


Saftey! Be aware, and remember protective eye equipment, when dealing with the combustion of fuels there is always a potential of explosions.


1. Air Flow

Open the compressed air valve on the ejector venturi system. This is the 1/4" valve where the air line connects. The monometer should respond easily upwards to 5 inH2O. Set the pressure drop across the reactor to about 3 inches of water. If the monometer does not respond, go back to Final Preparation Before Lighting.


2. Ignition:

Open the air inlet. Squirt in a bit of liquid fuel to start. Light with a propane torch about an inch from the inlet so as to provide oxygen for the propane torch. Make sure that the air is flowing into the reactor to be careful of potential back fire. You may need to keep the torch there for a minute or two. Be sure to close the cap on the ignition port when reactor is lit (and open the 1" air cowling port), and seal it with clay weatherstripping or RTV silicone prior to iginition.

Ignition has been shown to be possible with just a propane torch, with lower flows leading to faster initial ignition. Recommended reactor pressure reading: 1" H2O during ignition.


3. Flare

Within a few seconds of lighting, gas will come out of the flare. At first this may not be a combustable gas until the reactor gets up to temperature. Be sure to have a manual pilot light or propane torch to help burn off the tar and steam smoke on start up.  This will keep a good large pilot flame at where the syngas enters the swirl burner, and keep things clean until the syngas flame will sustain itself.  The extra flare will prevent unburned gas from floating around your work area.  Get a hand propane torch so you can do this, ideally with piezo-ignition.


If this initial period of uncombusted gases is a concern, propane can also be introduced just before the flare via a pumbing T and turned off after a few minutes of reactor warm up. There is a port that comes with the ejector venturi for this purpose.


4. Sustained Flare

After a few minutes you will be able to turn off your propane pilot light torch on the flare. Adjust the oxygen mixture on the flare to transition from a propane to woodgas flare (this is the 3/4" valve on your ejector).  Keep it handy in case the syngas flare goes out and you need to relight it quickly.  Remember do not breathe the gas when it is unburned.  After it is burned it is very clean.


Notice: When the O2 valve is closed too far, the flare does not have enough oxygen and it will rise up out of the flare stack. Because there may not be enough oxygen to competely combust the carbon monoxide and hydrogen, there could be some carbon monoxide being released near the flare that has not combusted. As you open the O2 valve, the flare will pull back into the flare stack. All of the woodgas should be combusting before halfway along the flare stack. This ensures a complete combustion.

Notice: When the O2 valve is opened the ejector will be pulling air through this port which will lower the vacuum that it pulls on the rest of the system. Notice that when the O2 valve is opened, the manometer will indicate that the pressure drop across the reactor (and the filter) lowers. Make sure that you are staying in range of the proper pull rate. You may need to increase the flow across the ejector to make up for this difference.


5. Proper Gas Pull Rates and Ranges

For starters, we suggest running the reactor at about 5" h2o vac, as read on the GEK manometer.  This is a robust pull rate that will ensure tar is converted and the char is burned into configuration quickly.


As for ongoing running, here's the range of gas pull rates you can explore, and where the "out of bounds" thresholds are to be found.  Remember this is the reactor only.  You can expect to see another 2-5" h2o with the reading after the filter.

10+ Overpull

8 Maximum

6 Good

5 Ideal

4 Good

2 OK

1 Minimum

0-1 Underpull

Overpull creates a mess of soot and weak gas

Underpull creates a mess of tars and richer gas. 




10. Filter

The manometer is your first indication that the filter media may be clogged.

If the filter media is working properly, generally there will be a 2-4 inch of water difference between the two of them.

If the reactor and filter pressure have a larger difference between them, it might be best to change your filter media.


11. Note rate of fuel consumption

All biomass is different. Check the fuel level every few minutes through the fill port until you get a feel for how quickly it lowers.   Do not let it go more than halfway to the nozzles before you refill. Without a hopper or auger filling option attached, the reactor will likely need more fuel every 5-10 minutes.Nonetheless, when first learning how the GEK runs, you should experiment without the hopper.


12. Ponder

Try and break it.  Figure out how and why it works.  Change the fuels.  Change all the internals around.  Make it better.  Send us your pictures and videos so we can ponder the mysteries together and tell others what you did. Enjoy!


Need Help?

contact: jay(at)


Go back to First-Run Start-Up Instructions

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