Attached are some pictures of my junkyard gasifier plant. Yes, it was built entirely from junk salvaged from the tip. Took about 2 years to collect enough to do it.
The Pyroliser unit is constructed from an old electric hot water urn boiler, the hopper is a garbage bin turned upside down (FEMA design). The promary gas cooler is made from some thin walled tube from an old bedhead, and is a pretty blue powder coated color, the secondary cooler is the same stuff, but a nice contrasting red. The water trap is an old jam jar, the Primary filter is made form an old vacuum cleaner with the insides constructed to the FEMA design. The secondary filter is constructed from an old paint tin that happened to fit a used caterpiller bulldozer paper element filter. Most of the odd pipe fittings were from my box of “stuff” and the various pipes were offcuts from jobs around the farm. The fan was a heater unit from a Toyota Corolla car that was dumped at the tip.
The junkyard gasifier is all mounted on an old 6 X 6 pallet and is reasonably moveable with the aid of the tractor.
I have also fitted a pyrometer inside the hearth to measure the combustion temperature. This got to 750 deg celcius during my tests, so it should crack tar OK.
In the pyroliser itself, I have allowed a secondary air intake (capped off at present) just in case the prmary air didn’t allow the temp to get hot enough to crack tars. I also have a small inspection port. (It was originally going to be the lighting port, but I decided that I didn’t want to pull the whole thing apart just to clean it out, so I cut a hole in the side to allow internal access and made it air tight with a silastic gasket).
The first test was spectacular. After about 10 mins I was refueling the unit and had a backfire, so it was producing combustable gas. I connected it to a 3.5 Kva Honda alternator set and started the generator on petrol. I turned off the petrol and shut off the drawing fan and closed the fan valve. The engine faulted and started coughing then stopped. The mixing valve was too course to allow adjustment, so I closed it off, restarted the generator on petrol, turned off the petrol and controlled the air mixture by lifting up the gas pipe from the intake. This got the engine running, but only for a few minutes at a time.
Obviously the quality of the gas was not good as I was using wood chips that were 1/2 composted. The next test will be with good quality wood chips and I expect better results.
The gas cooler was perfect with the pipe being touchable only 1 meter from the gas inlet. The other 6 meters of it was cool, so the thin walled pipe works very well. I could probably shorten it to one length, but given summers here get to 40 odd degrees, extra cooling is probably worth it. The cooler the gas, the more oxygen available to burn, and hence, more power. So I will probably leave it alone.
The next test of the junkyard gasifier will be with a larger generator. I have a 5 Kva Suberu (Robin) generator that has a failed electronic ignition unit. I have built a transistor ignition unit and am triggering it with a HAL effect sensor. This will allow me to vary the timing to optimise it for syngas.
Overall, I was pretty happy with the first test, and now have some experience with wood gas. No damage was done with the backfire, apart from singed eyebrows, but hey, isn’t that what they are for? Oh yes, don’t forget to wear safety glasses, I was and that probably saved me trip to hospital to remove bits of wood from my eyes.
If there is any one else around here (Northern NSW, Australia) experiementing with wood gas I would like to correspond with them. My e-mail is: peterlaughton at y7mail.com.au
Till next time,,, go go gas !!!!!!!