Hi Ray, Before going any further, let me make a suggestion. Forget the brain mary pot. Go to a real plumbing store and get a 4" nipple and 4" cap. Weld the nipple onto the tank and use the screw on lid to close up the reactor. Just had another thought. If your 4" nipple is as long as it can be (your hand has to reach to the bottom of the reactor to replace the nozzle) then it will also act as additional charcoal storage which equates into longer run time. For your 15HP engine, a 1" nozzle should work well. Since you are using this design reactor, you will need a cyclone to cut down on chuncks of charcoal being sucked over. (If your reactor was made from a steel bucket with removable lid, you could just lay a screen on top of the charcoal to keep it in the reactor) You should not need a cooler. Definately need a filter though. Kick these ideas around, but what ever you do, make sure your hopper lid is air tight.
About time you got a gasifier together to burn all that charcoal. 
Ray, once you get an engine fired up on charcoal you will grin from ear to ear, then go out and start making more! I am worried the Feds may see this as an addiction and step in to regulate it. Toooo much fun!
Gary in PA
Gary, If I go with the pipe nipple and cap there will be no “puffer lid”, since the inlet and outlet ports are the only other holes. I thought I would need a spring loaded lid in case of explosion? (BTW, managed to make another barrel of charcoal this morning. It is cooling down now.)
The key to a charcoal gasifier is making alot of high quality charcoal, fast! Here’s how I’ve been doing it lately:
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I start the burn by pouring some diesel on the wood and down along the inside of the barrel. Then I use a propane torch to lite the top AND the bottom of the burn thru the upright fat slits in the bottom side of the barrel. I lite the top first, then the smoke that is pouring up from the bottom fire, feeds the top fire. The two flame fronts meet in the middle, making the burn twice as fast. If the wind blows out the top flame, there is an incredible amount of smoke. I relite it with the propane torch. As long as there is a top flame, there is no smoke, only incredible flame. I use a piece of #8 (1/8 inch) mesh over the top of the after burner to stop lit flying ash.
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When all the coals are glowing, the burn is done. I do not use dirt to seal the large fat slits every 3 inches along the bottom side of the retort. Instead, I have an air tight finishing container that I dump the coals into. This frees up the retort for more production.
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I made a lite weight frame, 2 feet by 4 feet, for the #8 mesh. I lay this on the ground. Above this, I put the coarse mesh frame on a spacer. I dump the raw charcoal in and stomp it thru the coarse mesh onto the fine mesh. If the coarse mesh is thinner wire, it slices thru the charcoal easier and there are less fines. When the fine mesh frame is pretty full, I take the coarse mesh frame off and shake out the fines. I make sure the wind is at my back when I do this! I then pour the finished, graded charcoal into an air tight 55 gallon storage barrel. I don’t trust the fresh charcoal because of possible spontaneous combustion.
The only part of the process I dislike is the grading, but until I can come up with something better, this will have to do.
Steve, Thank you. Ha I’ve considered those ceramic welding nozzles and said to myself, nah, I’ve never seen anyone else use them before. Now I’m thinking hmm, just maybe. I’m also thinking of using the high temp ceramic paint but wonder how to do the curing process (if it’s not on an engine or exhaust system) I’m guessing it should be coated on inside and outside the reactor but fumes would be dangerous during a gasifier run yes? Should I use another way to heat up the reactor? Have you used this stuff before? Any ideas?
Ray, if you’re going with the pot hopper idea I think a collar should work or even just bolting tabs directly to the pot and sealing with silicone like the tabs that Gary is using on the tractor project above. I used silicone around my lid, let it skin for a couple hours, put waxed paper on it and then pressed and weighted it to the reactor, and let it cure for a day. Don’t know if this is the best way, but I haven’t seen too much about lid seal techniques. If this wasn’t working I was going to use fiberglass stove rope.
John
Hi JohnR.
The one DYI use of the fusible ceramic coatings was reported by John Blount. He said that the parts of the system subjected to fusible heat it worked fine for a hard protective surface that did not erode or react. Not heated to fusing it would just scrape off. It can be purchased as a powder. You add your own liquid vehicle to spray or paint on; water based or other. Would not be any fumes with a water based vehicle. Commercial guys send the coated parts out for furnace fuzing. Just like most job out their laser cutting.
Pottery kiln would do the job. Lots of pottery people around.
I’ve personally never had any problems using woven fiber glass stove rope down in the hot/hot areas. Just have to have stiff enough surfaces to now distort with the clamping forces needed.
Upper Raw fuel gasifier hopper goo/drool/condensate mucks it up. The high temp silicone moulded and then HT silicone greased is fine up there (DJ and VesaM). If lacking a good lip groove then many report HT silicone squeezed and worked into the fiberglass stove rope and allowed to cure works well to give durability to the hopper seal. This is not a problem area a charcoal gasifier should have. Heat Is. Neither are Poofs, Belches, or Fash Backs with charcoal. Cold moist charcoal you should only be getting non-combustible steam. CO flashes are really woosie compared to H2/CH4/tar vapor flashes. And they weak compared to gasoline. Put raw or partially cooked wood in a charcoal pot and then the possibilities and problems shift back to those of raw fuel gasification.
I’m strongly thinking just maybe on the ceramic nozzles myself.
Regards to all
Steve Unruh
Hey everyone, It was a few weeks ago I got the bright idea to put some used
motor oil in with the charcoal in the Simple-Fire. After running three fillings
through my Gravely mounted unit, I can say it kind of works and it is kind of a
problem. The oil is vaporized and condenses in the gas pipe and expecially the
filter. Oil on the filter catches the charcoal dust and eventually plugs up.
When you pull the foam rubber filter out, it is an oil soaked black mess. Some
of the oil that gets through the filter (must be well vaporized) will increase
engine HP due to the addition of these hydro carbons. If someone else wants to
give it a try, let me recommend you use no more than one quart of oil to a 55
gallon drum full of charcoal. Any takers???
Until later,
Gary in Pa
Steve, I did not know about these things. Can you get them as large as 1 1/4" ID?
John R. Looks like these could easily fit your 1/2" nozzle. Sure would be a lot easier than fusing a ceramic coating on your nozzle. Then again, my SS nozzle sheath is holding up fairly well. Really need to put the unit on a generator and just let it run. Steve, you mentioned a good target to aim for. Ie 2 hours per day run time.
Later,
Gary in PA
Gary. I -think- you need to “crack” the oil. Essentially heat it to vaporize it, then superheat the vapors as hot as you can get them. And/or just cool the gas, and condense out the reformed oil before it gets to your engine. I have a feeling you aren’t getting enough heat to it to crack all of it. Cracking should give you shorter carbon chains, that won’t reform as oil, but more like gas. I can’t remember if you need a catalyst to assist it or not.
Hi Gary I wonder if you couldn’t use the injected exhaust to sort of venturi in a small quantity of oil. Its hot so you would get some vapourizing of the oil and its measured to the output of the engine so you would get some flow control. You would not get the dust control but you would get the added hydrocarbons. Not about to try it though; all I have time for is looking these days. Burn ban is finally off so I made a batch last night. Very peaceful.
Best regards, David
Hi DavidB.
You sure shown me a thing or too with your big barrel softwood charcoal gasifier. Darn. I was going too small!
Look over John Rubins pictures and comments about his engine exhaust tapping off and injecting results. Sure looks simple and favorable for heat control and maybe better fuel economy.
Gary in PA it may have been me somewhere who did say design for a min 2 hour cycle a day for stationary electrical generation. Fits with DavidB, DJ and others I know with enough sun and installed solar PV to be self standing. They all must have enough battery banking for overnight carry over. The dedcated doing this with Dino fueling say best to engine genrate recharge in a 2 hour bulk engine 80% loaded recharge cycles. After that the battery bank charge acceptance rate cuts back leading to an under loaded engine/gen- head and fuel wastage. Be the same regardless of the engine fuel. That first ~25% of engine fuel usage on gensets just goes to keep the engine turing over, pumping oil (and maybe coolant water) and always wattage committed for cooling air.
I do not think the TIG ceramic cups come commonly in 1 1/4" size. Industrial may-b-e. But be an industrial price. Welding company I use say users needing that much metal lay down now pretty much using a submerged arc process.
Regards
Steve Unruh
Hi David, There is so little of the exhaust needed to control oxidation temp that it doesn’t create a venturi effect. I want to keep the Simple-Fire simple, but in the future can see adding a small copper line (to let some liquid like motor oil) drip oil onto the hot nozzle where it will then flow into the hot charcoal. This will definately work and the incomming oil may cool the oxidation reaction enough to forgo the exhaust. However, I really like keeping the exhaust to temper the temperature since it is always there, doesn’t clog up and a mess up in temp regulation WILL cause s melt down of the nozzle. Keep thinking.
Gary in PA
Hi Ray, I have not messed with wood gas units but do know they can puff! I have never had my charcoal gasifiers puff. Even when I take the lid off after running to add more charcoal, at the most, the charcoal gas will ignigte and burn in a lazy blue flame. Dump more charcoal on top and put the lid on. No puff. That has been my experiance so far.
You reallly need to start burning up your charcoal in an engine otherwise your wife will think you are turning into a coal miser.
Gary in PA
Thought I’d add my little fire extinguisher charcoal gasifier. First time I saw the picture of the motorcycle with the fire extinguisher on the back I wanted to build one.
The hose is heavy duty truck heater hose made of silicone, and seems to take the heat very well (good to 350deg continuous). It’s expensive, but not bad if only used for flexible connections.
Note the big hole in the bottom left corner of the fuel tank - to show there is no gasoline in there 
Here’s a youtube of it running:
William
William
I thought the same thing when I saw that extinguisher motorcycle. I’ve got a charcoal motorized bicycle engine build in progress. It’s a small 37 cc engine. I’m trying to figure out the carb and exhaust modifications now.
This looks like it’s working really well. Where’d you find the old extinguisher?
John
Scrap metal yard, they come in about once a month from someone in the business. That’s the first time I got one with the big screw on top - usually they are modern versions with a squeeze handle and pressure gauge. This one had a glass bottle suspended in a wire cage from the top, with a lead weight plug - so turned upside down would dump the bottle. I’m working on getting a 25 year old junk plasma cutter and wire welder running, and rigging up a scratch tig torch to eliminate a lot of the fabrication problems. Most of my welding equipment was stolen a few months ago and trying to rebuild…
Sorry to hear of the theft, that’s terrible. The large opening on top is what I noticed and looks ideal for a small hp setup. Great find. I’ll have to pay the scrap yard more frequent visits. Best of luck getting the fabrication equipment up and running.
I was walking through my shop today and happened to see one of my military Jerry Cans that holds 5 US gallons in a small footprint and got to thinking that it would probably work pretty sweet for a small charcoal gasifier. It could be tilted on a 45 degree with the filler cap at the very top and the nozzle near the bottom pointing up. The slope would automatically gravity feed the coal to the fire. A rolled up metal sheet could be pushed through the filler cap and then spread out inside along the sides if added heat protection would be necessary. The flat sides would make for easy flange attachment and the whole unit would not take up much space for applications like saddle bag mount on a motor bike. Just thinking out loud here.
Don M
Hello Mr. Gilmore, my name is Marco, I live in Florence Italy and I’m an little inventor also… I have found casually your charcoal thread and I decided to sign in. I think that charcoal can be used in the future for reduce a lot CO2 emissions and I think that another design can be used for semplify and increase a lot the efficency of your system using just the engine as energy source and just your filter modified for work as reactor/radiator/filter … all togheter. Why lost some heat from the exhaust gas of engine instead to use all energy released? We must not forget the law of conservation of energy!! Regards Marco
Hi Marco and welcome to this site. I love charcoal and can see some exciting uses for it. I am curious about your thoughts on increasing the efficiency of the generator. Have you done any work in this area or can you post some diagrams of your idea? Conserving energy is very important as we move into an era of higher energy costs. Right now our natural gas prices are at rock bottom but I bet that will change several decades from now. So as we develop wood gasification, we do need to keep thinking about efficiencies.
Thanks for joining in on the conversation, and more importantly, the doing.
Gary in PA
Hello Mr. Gilmour, thanks for reply me. Personally I think that wood is the fuel of future and our scientists are are too busy thinking to the god particle and not what mother nature offers us. However I think that we need to start from wood directly and not from charcoal. My main project isn’t the creation of syngas (CO/H2) but of methane (CH4). About this I do not understand why no one has used a catalyst to be used both as a filter as a catalyst at the same time processing the syngas into methane. From your tests you have found an best thing, exhaust gas can be reused again and again into the process, in fact as you wrote you produce CO2 and water steam and with right process can be transformed into burnable gas. Actually I’m working to an special burner/reactor/catalyst for obtain an complete gas process and for not have CO in output but just methane. Very Important thing is pirolisys zone, probably we need to use not conventional heat source. Regards Marco