Great point Brian. The whole reason behind the dimmer switch was to have throttling capabilities so I could play with optimal speed/gas quality combinations. Much better to play with air flow via a ball valve than to potentially wreck a motor. In fact, I better be sure this system is safe, because the intent is to allow others to replicate it. A ball valve is inherently safer.
I’m also a little worried about the vacuum motor being so close to the gas stream. I’ve already purchased a Rigid 6-gallon shop vac, but I haven’t had time to examine the motor, to see if there is any potential for spark. Brian, you sound like you know motors… Provided I make sure the vacuum is 100% air tight, do I have anything to fear about spark?
To be compliant in the “no welding required” spirit, I’m going to use a plant stand. I’ve seen a few at the nursery that are 16" diameter, heavy frame, and would hold the propane very steady. As soon as I demonstrate that indeed, no welding is required, I will then begin to systematically improve the base design with all kinds of enhancements – including welding and other more advanced fabrication techniques.
I certainly have nothing against welding. I just felt that it IS possible… and could be done as a response to the most often cited reason my friends don’t jump into gasification – “I don’t know how to weld,” or “I don’t know a welder.” No excuses now
I just need to make sure that it makes great gas, and is very safe… Might have a long way to go still…
Troy, the reason I’m saying this is because I’ve been through the same mode of thinking. FORGET the no welding thing! You will spend WAY more money not welding than welding. Not welding kept me on the sidelines for 2 1/2 years. I’m now done with my gasifier unit and am 2 weeks away from finishing the cleaning system. A 110 volt stick welder is less than $150. A good sheild with auto darkening is another $100. You are going to have to weld with your design. How are you going to clean it out? Answer a pipe nipple and cap welded at the bottom end of the tank. It can double as the nozzle entrance. A propane tank already has a base welded on it so don’t spend any more time or money on that. Weld a 4 inch nipple to the top where the 3/4 outlet used to be and weld a pipe across the cap and now you have a refill lid. Weld an 1 1/2 or 2 inch coupling onto the top side of the tank and you have a gas outlet. Hard pipe that down to your cyclone and you have a good, durable system. Believe me, if you don’t want to weld or can’t find someone who can, this is the wrong hobby for you. I learned this the hard way and don’t want to see you do the same thing. Get a stick welder and go for it!
about the shop vac…
The motor is external or does the cooling comes from the air sucked trough the filters ? ( as most ordinary vac’s do )
If its not a “brushless” then you should be careful at any given time.
If it is a brushless, then no worry’s as long you make air tight electrical connections with the switches, you could then also run the vac cleaner with a soft starter, this gives the ability to adjust the RPM as well.
Hi Troy, I looked at your latest drawing and here are a few thoughts. Is the nozzle diameter only 5/16"? That seems to me to be too small for the size engine you are running. Maybe for a 5 hp it would be OK. Give it a try but my bet is it will constrict your flow too much. Cyclone = good. The shopvac, as Koen pointed out, could be a problem. You do not what sparks in your charcoal gas in case there is an air leak upstream. BoooooM! Where is your final dust filter? Open cell foam rubber topped with wool cloth works really well for me. Easy to clean and maintain. Consider putting it on be for the shopvac. Actually, why not eliminate the shopvac and put on an in line bilge blower. They cost about $25 and put a pull on the charcoal gas that is more like the pull put on by the engine. Finally, place your three way valve as close to the engine as possible. This makes it easier to get the correct stoichiometric mixture sooner as the amount of charcoal gas in the line is less.
Off to help my daughters get their new homes ready
Gary in PA
Thanks for the feedback on the shop vac… I’m going to go with an inline unit, but I have a (rather urgent) question. Can I use an inline fan instead of a bilge blower? I already have access to one, and I can’t seem to tell the difference… our big build day is this Saturday, and i want to make sure I purchase the right blower in time for shipment. Any quick response would be most appreciated.
Also, now that the shop vac is gone, so goes the media filter than comes with it… No big deal, because we can do the open cell foam + wool blanket.
Hi Troy, I like the inline bilge blowers as well and you can find them at any boat store or mega outdoor place. Another fun feature is you can fit them onto 3 or 4 inch PVC plumbing couplers making them easy to then reduce to a threaded pipe. That would reduce your chance of leaking but seperating the pathways is still a good idea. Have a good build
David
Troy: I know just enough about electric motors to know when I should probably worry about something, but that is about it. It looks like Koen and Gary G. have told you more than I could.
I do know (from reading more-knowledgable-than-I people here) that some vacuums cool their motors with air being pulled through the vacuum using the vacuum exhaust. I know this is BAD for us. Some vacuums have an isolated cooling vent assemply for the motor (look for motors with dedicated inlet/exhaust vents for the motor that aren’t affected by the vacuum itself.) These are “generally” more OK.
Beyond basic physics and mechanics, that is about the limit to what I know about electric motors.
OK Troy, that is the inline or bilge blower. They come with a three or four inch opening. I like the three inch. Get two rubber boots from the hardware store that are used for plastic piping to neck it down from three (or four) inch to 1.5 inches. Looking forward to how your build goes!
Gary in PA
Hi Bryan… I could put one together, but we’ve spent the last 3 months building the “real deal,” vs. the proof of concept, as seen in that picture. A lot of the parts were cut, epoxied, or modified in different ways.
If you’re very interested in building our concept model, I’d recommend you watching my video… I walk through all the parts: The OpenFire Charcoal Gasifier - YouTube
However, if you can wait a week or so, we will be flaring off the new version. It will be released as open source (CC-BY-SA).
Just watched your U-tube video and thought it was great. I especially liked you explanation of why the gas was cooled down to almost ambient but the time it reach the “rubber” hose that went from the “gas generator” to the cyclone. I am sitting on 200 gal. of charcoal that I would like to use in a electric generator like you have built. Good job.TomC
As written into my closed thread when water steam is REALLY cracked and burned the flame is invisible but with just water steam you can’t obtain an fast water cracking also if you use red carbon you need an catalyst and “activated water”. Testing Testing Testing
