Ok so I got a weight on the fuel in the kiln after its second run in there and it knocked out another 15 lbs exactly. So its repeating.
However this run I thought was sort of odd. It ran a bit cooler, but more stable. When It started gasifying I did my normal routine of throttling the valves down but I found it ran too cool; so I openned them back up. It also ran even cleaner than before hardly any smoke at all and wasnt trying to melt a hole through the earth. I think the water vapor from the kiln maybe taming the gas down a bit. It also ran longer on less wood than the first run. It ran 4 1/2 hours Believe it or not I still have left over wood from that pile I showed in the earlier post.
3 batch runs will easily yield a 55 gallon drum. So roughly 1/3 reduction plus what little fuel in used in the retort.
Oh one thing I did on this run they may have contributed to it running cooler and more stable. Those second stage air tubes that hold up the retort were sagging. So I grabbed the ol pipe wrench and spun them 180*. There are something like seven 1/2" holes drilled into it and every other one is drilled through to the other side of the tubes. So one side has half as many holes. Originally the side that had the most holes were pointed inward to center. I think this reversing this may be why its running cleaner and this is probably the right way to do it and point those out so air can mix as the gas exits the burn chamber.
I am going to order 1 1/4 thick wall pipe to replace this tube and that is how I will set this up this next time. Yeah this is probably why this run was different than any others beforel.
I also did a pre dry test on my green fire wood for the house fire , i have a 55gal drum sat over a fire pit in the ground the drum has a 6 inch central flu pipe going up the middle , and to heat it i just raked up all the mess on the ground into the hole in the ground ( Mostly gum leaves and twigs ) you would have thought it was petrol i was pouring under there if you have never seen gum leaves burn before , kept a pretty consistent burn going for a few hours while cleaning up , ended up with lovely scorched wood that was a lot lighter in weight but still needed to wait a few months to get the middle dry enough to burn clean . Pallet wood is also a great fuel for doing this also .
Dave
Ok I built the stainless jet and ran the first test run tonight. I got a weight on the charcoal as well, a 5 gallon pale came to 7.5 lbs not including the weight the bucket. So total hopper load weight is 15 lbs.
I got around a 2 hour and 50 minute run. It consumed the full water tank and ran @ 2 kW for the first two hours. However after that it just would not pull that load so reduced it down to 1.5 kW for the remaining 50 minutes. Combustion zone is dead center however I suspect the reduced char depth is the cause for why it would not pull as strong as before. So not going to change anything yet and run again. If this repeats then Im going to chop 2 inches off.
So tonights run averaged 2.7 lbs per net kW / Hour
The other day with the 3 hour run with a net 6.9 kW/hr net output. If I use this wieght the average weigth per kW/hr is actually a bit more than prevously calculated. About 2.2 lbs per kW/hr. That is still very good though. The last time I weighed the fuel I was using that slat wood and that was a mix of different woods so more likely it was softer woods giving a lighter weight.
I just realized I had the air compressor turned on. I bet that thing was trying to start causing that issue later in the run. I never heard it turn on though. But it was plugged in and it was on and there are leaks in the hoses. I generally only turn it on when I need to run the air.
So this happened today. Decided to try and come up with a simple design that could be built without any welding and could be manufactured really cheap.
Critieria:
No welding required option
Down Draft Configuration with Water Injection
Use Comon off the shelf components
DIY friendly
Can be addapted to a range of tanks and drum with minor design changes
Ok so this version would require some welding as Im using a tank instead of a drum. However if a drum is used you could build this without any welding. The con is the drum is thinner metal versus a propain tank or portable air tank will be much more robust.
So to create the lid you will need to cut the dome off one side of the tank and weld a duct flange to the tank and then a plate flange to the lid to accomade a clamp plate to secure the flanged rope seal.
The concept is a through port design where the intake of the unit portrudes through the top of the lid. This is a 1 1/4 inch pipe. Then bellow this pipe is a choke plate that forces flows to take path around it get as much reaction as possible. The bottom side of this plate is an exhaust tube with vents to the top and then this pipe nipple is threaded into a pipe flange on that is bolted to the bottom side of the tank. This pipe is a 2 inch X 4 nipple. The choke plate sepperates the exhaust side from the top intake side. The bottom will be double flanged one on the inside and one on the outside. Now you could creat a second tank to place under it and using the pipe flanges you could screw them together with 2 inch nipple inbetween. The bottom would be a settling tank / gas pre cooler basically. This way the gas will be cool enough for the red flex hose we use to connect it to a filter. So from here you would connect the unit to a drum filter with an Amatek Blower mounted to its lid for starting. Then hose port out to engine.
The water drip will be integrated into the spring retainer. Note the spring coil around the intake pipe. There is a pipe half couple that put presure on the spring and there is a bottle stand weld to it. You simply use a 2 ltr soda bottle. You will need to install a drip valve in the bottom. I was thinking 3D printing a simple valve with a barb on one end. Then you drill a hole in the bottom of the 2 ltr and install a rubber gromet along with some sylicone it should seal.
So you could easily see your drip rate with this set up. The water as it drips in will more than likely hit the walls and evaporate as it migrates down to the jet holes. If not it will hit the choke plate and evaporate there. So very easy to control the water and this should yeild a 100% evaporation process. So it should be very eficient processing the resulting steam
Interesting concept, I like the choke/baffle that elongates the active zone to really make use of the diameter of the container. I guess the closest thing would be like a Kalle but actually DIY friendly and not on the razors edge of melting down.
I was thinking you could just line the walls with the ceramic insulation of what ever vessel you use. For the plate another but more expensive option would be use a butt weld bell pipe reducer. But just going to try the plate first I think it will be fine with a thick plate steel here.
Just for you Tom I revised it so it has a heavy duty coupler there. This way if you do degrade the nozzles you only have to replace this coupler. Plus its 4 times thicker so it should yeild a pretty long service life.
I was thinking of the same thing. I’m finally getting back to finishing the gasifier for my saw mill and I think I’ll build one for my log splitter using this design except welded. I like the mental image of the gas spilling over the edge of the plate. I was originally interested in no-weld gasifiers for homesteaders without welding skills but later decided that if a person couldn’t be bothered to learn basic skills like simple welding I didn’t want to be involved with them.
Here it is set up on the gas pre cooler. Its basically built like the top but the flange is bolted together and the dome end off that tank is flipped to create stand for it. Then the double pipe flanges; the inside extends a 2 inch pipe to direct the gas to the bottom so it has to take the longest path possible before exiting the exhaust port. < that part is not shown. But it will be located at the top for the gas to exit to a remote drum filter. Its just another pipe flange that will get bolted to the side up at the top. The 2 inch pipe flange on the top side is for a 2 inch close nipple to connect the reactor to it. Im planning to mount the lower unit on a hand cart. Then the reactor can be unscrewed from it and taken to be emptied and serviced.
The blower adapter I make for the Ametek I use will be the same NPT size as the intake tube. This is a back up plan for lighting the unit. I can already see it will be a bear to get lit up and will probably take forever to make volitile gas. So the back up plan will be install the blower on the intake and back draft the igntion source from its igntion port to migrate and establish combustion at the nozzles. Then you remove the blower and screw it onto the remote filter and run like you would any gasifier.
I ran the numbers on this and if braught to market it will retail for $2400.00. Thats just for this kit, you would have to cut, mod, weld and assemble it yourself. I basically set up orderes with all vendors with all the parts that would be required to create this in a complete kit where nothing would need to be bought. It would include everything including the hoses, couplers, mixer assembly the engine adapter, the drum, tanks all the pipe fittings etc etc. It would come with everything. You just supply the elbow grease to cut, mod, weld and assemble it.
Ok I slapped together a proof of concept. It works!
I tore down the DFX proto and converted it into this concept. I dont get very long run time though. I think the hopper is too small. They always seem to need a certain amount of charcoal above and bellow the nozzle (or jets in this case.) Plus the charcoal Im running is from a bunch of softwood I aquired and converted to charcoal. I can run the blower on just 12 volts DC and it will sustain the unit. Its probably close to the volume the small 212cc generator would pull. Im going to run it tonight off the blower and test it a bit and then tomorrow I might try and run the little WEN 212cc genny with it.
This maybe the direction I may go. I can produce this unit in a kit form for half the cost of the CFX RTR. And can get the cost even cheaper with the basic kits. I think this will be a more viable product plus it would put the actual price point in line with the market price point perception.
Ran two more hopper loads with the blower running on 24 Volts. That seems like the best voltage for these smaller units. Thats the nice thing about the Ametek blowers you can tune them to the size of your gasifier and match the load of the application.
It lights up just fine from the outside ignition its not a problem like I had thought it would be. The water drip is much easier to control and I dont have any flow issues. Set it and forget it. The boiler pot concept works as planned. It runs very stable and so far its checked all the boxes of what I was trying to accoplish.
I will be playing with that with my other company. Funding is tight so I can’t afford the equipment yet. But I will be playing with 3D printed lost invesment casting soon. Plus Ill be getting the equipment for Carbon Fiber cloth lamination and developing a Lexan forming machine for DIY’ers
